fs: yaffs: Import yaffs from Thu Dec 23 13:31:37 2010 +1300
authorArve Hjønnevåg <arve@android.com>
Wed, 19 May 2010 03:35:30 +0000 (20:35 -0700)
committerColin Cross <ccross@android.com>
Tue, 14 Jun 2011 16:09:13 +0000 (09:09 -0700)
commit ddf33fed15c2376bfb602d62dd018c63fce60df8
Author: Timothy Manning <tfhmanning@gmail.com>
Date:   Thu Dec 23 13:31:37 2010 +1300

    yaffs updated direct/timothy_tests/quick_tests
Signed-off-by: Timothy Manning <tfhmanning@gmail.com>
Change-Id: I5bbe5a05277bdf8a6fe188bbe4c77725b3fa2aae
Signed-off-by: Dima Zavin <dima@android.com>
45 files changed:
fs/Kconfig
fs/Makefile
fs/yaffs2/Kconfig [new file with mode: 0644]
fs/yaffs2/Makefile [new file with mode: 0644]
fs/yaffs2/yaffs_allocator.c [new file with mode: 0644]
fs/yaffs2/yaffs_allocator.h [new file with mode: 0644]
fs/yaffs2/yaffs_attribs.c [new file with mode: 0644]
fs/yaffs2/yaffs_attribs.h [new file with mode: 0644]
fs/yaffs2/yaffs_bitmap.c [new file with mode: 0644]
fs/yaffs2/yaffs_bitmap.h [new file with mode: 0644]
fs/yaffs2/yaffs_checkptrw.c [new file with mode: 0644]
fs/yaffs2/yaffs_checkptrw.h [new file with mode: 0644]
fs/yaffs2/yaffs_ecc.c [new file with mode: 0644]
fs/yaffs2/yaffs_ecc.h [new file with mode: 0644]
fs/yaffs2/yaffs_getblockinfo.h [new file with mode: 0644]
fs/yaffs2/yaffs_guts.c [new file with mode: 0644]
fs/yaffs2/yaffs_guts.h [new file with mode: 0644]
fs/yaffs2/yaffs_linux.h [new file with mode: 0644]
fs/yaffs2/yaffs_mtdif.c [new file with mode: 0644]
fs/yaffs2/yaffs_mtdif.h [new file with mode: 0644]
fs/yaffs2/yaffs_mtdif1.c [new file with mode: 0644]
fs/yaffs2/yaffs_mtdif1.h [new file with mode: 0644]
fs/yaffs2/yaffs_mtdif2.c [new file with mode: 0644]
fs/yaffs2/yaffs_mtdif2.h [new file with mode: 0644]
fs/yaffs2/yaffs_nameval.c [new file with mode: 0644]
fs/yaffs2/yaffs_nameval.h [new file with mode: 0644]
fs/yaffs2/yaffs_nand.c [new file with mode: 0644]
fs/yaffs2/yaffs_nand.h [new file with mode: 0644]
fs/yaffs2/yaffs_packedtags1.c [new file with mode: 0644]
fs/yaffs2/yaffs_packedtags1.h [new file with mode: 0644]
fs/yaffs2/yaffs_packedtags2.c [new file with mode: 0644]
fs/yaffs2/yaffs_packedtags2.h [new file with mode: 0644]
fs/yaffs2/yaffs_tagscompat.c [new file with mode: 0644]
fs/yaffs2/yaffs_tagscompat.h [new file with mode: 0644]
fs/yaffs2/yaffs_tagsvalidity.c [new file with mode: 0644]
fs/yaffs2/yaffs_tagsvalidity.h [new file with mode: 0644]
fs/yaffs2/yaffs_trace.h [new file with mode: 0644]
fs/yaffs2/yaffs_verify.c [new file with mode: 0644]
fs/yaffs2/yaffs_verify.h [new file with mode: 0644]
fs/yaffs2/yaffs_vfs.c [new file with mode: 0644]
fs/yaffs2/yaffs_yaffs1.c [new file with mode: 0644]
fs/yaffs2/yaffs_yaffs1.h [new file with mode: 0644]
fs/yaffs2/yaffs_yaffs2.c [new file with mode: 0644]
fs/yaffs2/yaffs_yaffs2.h [new file with mode: 0644]
fs/yaffs2/yportenv.h [new file with mode: 0644]

index 19891aab9c6ed7255388f175eabfcd7e4f5bb253..88701cc00e0ce403f482a7efe91a9911286e3a9f 100644 (file)
@@ -192,6 +192,10 @@ source "fs/hfsplus/Kconfig"
 source "fs/befs/Kconfig"
 source "fs/bfs/Kconfig"
 source "fs/efs/Kconfig"
+
+# Patched by YAFFS
+source "fs/yaffs2/Kconfig"
+
 source "fs/jffs2/Kconfig"
 # UBIFS File system configuration
 source "fs/ubifs/Kconfig"
index fb68c2b8cf8a73626bc2900048a0d4928993c365..2999b4d4b26795a21904278300038420c50ca74e 100644 (file)
@@ -124,3 +124,6 @@ obj-$(CONFIG_GFS2_FS)           += gfs2/
 obj-$(CONFIG_EXOFS_FS)          += exofs/
 obj-$(CONFIG_CEPH_FS)          += ceph/
 obj-$(CONFIG_PSTORE)           += pstore/
+
+# Patched by YAFFS
+obj-$(CONFIG_YAFFS_FS)         += yaffs2/
diff --git a/fs/yaffs2/Kconfig b/fs/yaffs2/Kconfig
new file mode 100644 (file)
index 0000000..6354140
--- /dev/null
@@ -0,0 +1,161 @@
+#
+# YAFFS file system configurations
+#
+
+config YAFFS_FS
+       tristate "YAFFS2 file system support"
+       default n
+       depends on MTD_BLOCK
+       select YAFFS_YAFFS1
+       select YAFFS_YAFFS2
+       help
+         YAFFS2, or Yet Another Flash Filing System, is a filing system
+         optimised for NAND Flash chips.
+
+         To compile the YAFFS2 file system support as a module, choose M
+         here: the module will be called yaffs2.
+
+         If unsure, say N.
+
+         Further information on YAFFS2 is available at
+         <http://www.aleph1.co.uk/yaffs/>.
+
+config YAFFS_YAFFS1
+       bool "512 byte / page devices"
+       depends on YAFFS_FS
+       default y
+       help
+         Enable YAFFS1 support -- yaffs for 512 byte / page devices
+
+         Not needed for 2K-page devices.
+
+         If unsure, say Y.
+
+config YAFFS_9BYTE_TAGS
+       bool "Use older-style on-NAND data format with pageStatus byte"
+       depends on YAFFS_YAFFS1
+       default n
+       help
+
+         Older-style on-NAND data format has a "pageStatus" byte to record
+         chunk/page state.  This byte is zero when the page is discarded.
+         Choose this option if you have existing on-NAND data using this
+         format that you need to continue to support.  New data written
+         also uses the older-style format.  Note: Use of this option
+         generally requires that MTD's oob layout be adjusted to use the
+         older-style format.  See notes on tags formats and MTD versions
+         in yaffs_mtdif1.c.
+
+         If unsure, say N.
+
+config YAFFS_DOES_ECC
+       bool "Lets Yaffs do its own ECC"
+       depends on YAFFS_FS && YAFFS_YAFFS1 && !YAFFS_9BYTE_TAGS
+       default n
+       help
+         This enables Yaffs to use its own ECC functions instead of using
+         the ones from the generic MTD-NAND driver.
+
+         If unsure, say N.
+
+config YAFFS_ECC_WRONG_ORDER
+       bool "Use the same ecc byte order as Steven Hill's nand_ecc.c"
+       depends on YAFFS_FS && YAFFS_DOES_ECC && !YAFFS_9BYTE_TAGS
+       default n
+       help
+         This makes yaffs_ecc.c use the same ecc byte order as Steven
+         Hill's nand_ecc.c. If not set, then you get the same ecc byte
+         order as SmartMedia.
+
+         If unsure, say N.
+
+config YAFFS_YAFFS2
+       bool "2048 byte (or larger) / page devices"
+       depends on YAFFS_FS
+       default y
+       help
+         Enable YAFFS2 support -- yaffs for >= 2K bytes per page devices
+
+         If unsure, say Y.
+
+config YAFFS_AUTO_YAFFS2
+       bool "Autoselect yaffs2 format"
+       depends on YAFFS_YAFFS2
+       default y
+       help
+         Without this, you need to explicitely use yaffs2 as the file
+         system type. With this, you can say "yaffs" and yaffs or yaffs2
+         will be used depending on the device page size (yaffs on
+         512-byte page devices, yaffs2 on 2K page devices).
+
+         If unsure, say Y.
+
+config YAFFS_DISABLE_TAGS_ECC
+       bool "Disable YAFFS from doing ECC on tags by default"
+       depends on YAFFS_FS && YAFFS_YAFFS2
+       default n
+       help
+         This defaults Yaffs to using its own ECC calculations on tags instead of
+         just relying on the MTD.
+         This behavior can also be overridden with tags_ecc_on and
+         tags_ecc_off mount options.
+
+         If unsure, say N.
+
+config YAFFS_ALWAYS_CHECK_CHUNK_ERASED
+       bool "Force chunk erase check"
+       depends on YAFFS_FS
+       default n
+       help
+          Normally YAFFS only checks chunks before writing until an erased
+         chunk is found. This helps to detect any partially written
+         chunks that might have happened due to power loss.
+
+         Enabling this forces on the test that chunks are erased in flash
+         before writing to them. This takes more time but is potentially
+         a bit more secure.
+
+         Suggest setting Y during development and ironing out driver
+         issues etc. Suggest setting to N if you want faster writing.
+
+         If unsure, say Y.
+
+config YAFFS_EMPTY_LOST_AND_FOUND
+       bool "Empty lost and found on boot"
+       depends on YAFFS_FS
+       default n
+       help
+         If this is enabled then the contents of lost and found is
+         automatically dumped at mount.
+
+         If unsure, say N.
+
+config YAFFS_DISABLE_BLOCK_REFRESHING
+       bool "Disable yaffs2 block refreshing"
+       depends on YAFFS_FS
+       default n
+       help
+        If this is set, then block refreshing is disabled.
+        Block refreshing infrequently refreshes the oldest block in
+        a yaffs2 file system. This mechanism helps to refresh flash to
+        mitigate against data loss. This is particularly useful for MLC.
+
+         If unsure, say N.
+
+config YAFFS_DISABLE_BACKGROUND
+       bool "Disable yaffs2 background processing"
+       depends on YAFFS_FS
+       default n
+       help
+        If this is set, then background processing is disabled.
+        Background processing makes many foreground activities faster.
+
+        If unsure, say N.
+
+config YAFFS_XATTR
+       bool "Enable yaffs2 xattr support"
+       depends on YAFFS_FS
+       default y
+       help
+        If this is set then yaffs2 will provide xattr support.
+        If unsure, say Y.
diff --git a/fs/yaffs2/Makefile b/fs/yaffs2/Makefile
new file mode 100644 (file)
index 0000000..e63a28a
--- /dev/null
@@ -0,0 +1,17 @@
+#
+# Makefile for the linux YAFFS filesystem routines.
+#
+
+obj-$(CONFIG_YAFFS_FS) += yaffs.o
+
+yaffs-y := yaffs_ecc.o yaffs_vfs.o yaffs_guts.o yaffs_checkptrw.o
+yaffs-y += yaffs_packedtags1.o yaffs_packedtags2.o yaffs_nand.o
+yaffs-y += yaffs_tagscompat.o yaffs_tagsvalidity.o
+yaffs-y += yaffs_mtdif.o yaffs_mtdif1.o yaffs_mtdif2.o
+yaffs-y += yaffs_nameval.o yaffs_attribs.o
+yaffs-y += yaffs_allocator.o
+yaffs-y += yaffs_yaffs1.o
+yaffs-y += yaffs_yaffs2.o
+yaffs-y += yaffs_bitmap.o
+yaffs-y += yaffs_verify.o
+
diff --git a/fs/yaffs2/yaffs_allocator.c b/fs/yaffs2/yaffs_allocator.c
new file mode 100644 (file)
index 0000000..f9cd5be
--- /dev/null
@@ -0,0 +1,396 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_allocator.h"
+#include "yaffs_guts.h"
+#include "yaffs_trace.h"
+#include "yportenv.h"
+
+#ifdef CONFIG_YAFFS_KMALLOC_ALLOCATOR
+
+void yaffs_deinit_raw_tnodes_and_objs(struct yaffs_dev *dev)
+{
+       dev = dev;
+}
+
+void yaffs_init_raw_tnodes_and_objs(struct yaffs_dev *dev)
+{
+       dev = dev;
+}
+
+struct yaffs_tnode *yaffs_alloc_raw_tnode(struct yaffs_dev *dev)
+{
+       return (struct yaffs_tnode *)kmalloc(dev->tnode_size, GFP_NOFS);
+}
+
+void yaffs_free_raw_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
+{
+       dev = dev;
+       kfree(tn);
+}
+
+void yaffs_init_raw_objs(struct yaffs_dev *dev)
+{
+       dev = dev;
+}
+
+void yaffs_deinit_raw_objs(struct yaffs_dev *dev)
+{
+       dev = dev;
+}
+
+struct yaffs_obj *yaffs_alloc_raw_obj(struct yaffs_dev *dev)
+{
+       dev = dev;
+       return (struct yaffs_obj *)kmalloc(sizeof(struct yaffs_obj));
+}
+
+void yaffs_free_raw_obj(struct yaffs_dev *dev, struct yaffs_obj *obj)
+{
+
+       dev = dev;
+       kfree(obj);
+}
+
+#else
+
+struct yaffs_tnode_list {
+       struct yaffs_tnode_list *next;
+       struct yaffs_tnode *tnodes;
+};
+
+struct yaffs_obj_list {
+       struct yaffs_obj_list *next;
+       struct yaffs_obj *objects;
+};
+
+struct yaffs_allocator {
+       int n_tnodes_created;
+       struct yaffs_tnode *free_tnodes;
+       int n_free_tnodes;
+       struct yaffs_tnode_list *alloc_tnode_list;
+
+       int n_obj_created;
+       struct yaffs_obj *free_objs;
+       int n_free_objects;
+
+       struct yaffs_obj_list *allocated_obj_list;
+};
+
+static void yaffs_deinit_raw_tnodes(struct yaffs_dev *dev)
+{
+
+       struct yaffs_allocator *allocator =
+           (struct yaffs_allocator *)dev->allocator;
+
+       struct yaffs_tnode_list *tmp;
+
+       if (!allocator) {
+               YBUG();
+               return;
+       }
+
+       while (allocator->alloc_tnode_list) {
+               tmp = allocator->alloc_tnode_list->next;
+
+               kfree(allocator->alloc_tnode_list->tnodes);
+               kfree(allocator->alloc_tnode_list);
+               allocator->alloc_tnode_list = tmp;
+
+       }
+
+       allocator->free_tnodes = NULL;
+       allocator->n_free_tnodes = 0;
+       allocator->n_tnodes_created = 0;
+}
+
+static void yaffs_init_raw_tnodes(struct yaffs_dev *dev)
+{
+       struct yaffs_allocator *allocator = dev->allocator;
+
+       if (allocator) {
+               allocator->alloc_tnode_list = NULL;
+               allocator->free_tnodes = NULL;
+               allocator->n_free_tnodes = 0;
+               allocator->n_tnodes_created = 0;
+       } else {
+               YBUG();
+       }
+}
+
+static int yaffs_create_tnodes(struct yaffs_dev *dev, int n_tnodes)
+{
+       struct yaffs_allocator *allocator =
+           (struct yaffs_allocator *)dev->allocator;
+       int i;
+       struct yaffs_tnode *new_tnodes;
+       u8 *mem;
+       struct yaffs_tnode *curr;
+       struct yaffs_tnode *next;
+       struct yaffs_tnode_list *tnl;
+
+       if (!allocator) {
+               YBUG();
+               return YAFFS_FAIL;
+       }
+
+       if (n_tnodes < 1)
+               return YAFFS_OK;
+
+       /* make these things */
+
+       new_tnodes = kmalloc(n_tnodes * dev->tnode_size, GFP_NOFS);
+       mem = (u8 *) new_tnodes;
+
+       if (!new_tnodes) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                       "yaffs: Could not allocate Tnodes");
+               return YAFFS_FAIL;
+       }
+
+       /* New hookup for wide tnodes */
+       for (i = 0; i < n_tnodes - 1; i++) {
+               curr = (struct yaffs_tnode *)&mem[i * dev->tnode_size];
+               next = (struct yaffs_tnode *)&mem[(i + 1) * dev->tnode_size];
+               curr->internal[0] = next;
+       }
+
+       curr = (struct yaffs_tnode *)&mem[(n_tnodes - 1) * dev->tnode_size];
+       curr->internal[0] = allocator->free_tnodes;
+       allocator->free_tnodes = (struct yaffs_tnode *)mem;
+
+       allocator->n_free_tnodes += n_tnodes;
+       allocator->n_tnodes_created += n_tnodes;
+
+       /* Now add this bunch of tnodes to a list for freeing up.
+        * NB If we can't add this to the management list it isn't fatal
+        * but it just means we can't free this bunch of tnodes later.
+        */
+
+       tnl = kmalloc(sizeof(struct yaffs_tnode_list), GFP_NOFS);
+       if (!tnl) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                       "Could not add tnodes to management list");
+               return YAFFS_FAIL;
+       } else {
+               tnl->tnodes = new_tnodes;
+               tnl->next = allocator->alloc_tnode_list;
+               allocator->alloc_tnode_list = tnl;
+       }
+
+       yaffs_trace(YAFFS_TRACE_ALLOCATE,"Tnodes added");
+
+       return YAFFS_OK;
+}
+
+struct yaffs_tnode *yaffs_alloc_raw_tnode(struct yaffs_dev *dev)
+{
+       struct yaffs_allocator *allocator =
+           (struct yaffs_allocator *)dev->allocator;
+       struct yaffs_tnode *tn = NULL;
+
+       if (!allocator) {
+               YBUG();
+               return NULL;
+       }
+
+       /* If there are none left make more */
+       if (!allocator->free_tnodes)
+               yaffs_create_tnodes(dev, YAFFS_ALLOCATION_NTNODES);
+
+       if (allocator->free_tnodes) {
+               tn = allocator->free_tnodes;
+               allocator->free_tnodes = allocator->free_tnodes->internal[0];
+               allocator->n_free_tnodes--;
+       }
+
+       return tn;
+}
+
+/* FreeTnode frees up a tnode and puts it back on the free list */
+void yaffs_free_raw_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
+{
+       struct yaffs_allocator *allocator = dev->allocator;
+
+       if (!allocator) {
+               YBUG();
+               return;
+       }
+
+       if (tn) {
+               tn->internal[0] = allocator->free_tnodes;
+               allocator->free_tnodes = tn;
+               allocator->n_free_tnodes++;
+       }
+       dev->checkpoint_blocks_required = 0;    /* force recalculation */
+}
+
+static void yaffs_init_raw_objs(struct yaffs_dev *dev)
+{
+       struct yaffs_allocator *allocator = dev->allocator;
+
+       if (allocator) {
+               allocator->allocated_obj_list = NULL;
+               allocator->free_objs = NULL;
+               allocator->n_free_objects = 0;
+       } else {
+               YBUG();
+       }
+}
+
+static void yaffs_deinit_raw_objs(struct yaffs_dev *dev)
+{
+       struct yaffs_allocator *allocator = dev->allocator;
+       struct yaffs_obj_list *tmp;
+
+       if (!allocator) {
+               YBUG();
+               return;
+       }
+
+       while (allocator->allocated_obj_list) {
+               tmp = allocator->allocated_obj_list->next;
+               kfree(allocator->allocated_obj_list->objects);
+               kfree(allocator->allocated_obj_list);
+
+               allocator->allocated_obj_list = tmp;
+       }
+
+       allocator->free_objs = NULL;
+       allocator->n_free_objects = 0;
+       allocator->n_obj_created = 0;
+}
+
+static int yaffs_create_free_objs(struct yaffs_dev *dev, int n_obj)
+{
+       struct yaffs_allocator *allocator = dev->allocator;
+
+       int i;
+       struct yaffs_obj *new_objs;
+       struct yaffs_obj_list *list;
+
+       if (!allocator) {
+               YBUG();
+               return YAFFS_FAIL;
+       }
+
+       if (n_obj < 1)
+               return YAFFS_OK;
+
+       /* make these things */
+       new_objs = kmalloc(n_obj * sizeof(struct yaffs_obj), GFP_NOFS);
+       list = kmalloc(sizeof(struct yaffs_obj_list), GFP_NOFS);
+
+       if (!new_objs || !list) {
+               if (new_objs) {
+                       kfree(new_objs);
+                       new_objs = NULL;
+               }
+               if (list) {
+                       kfree(list);
+                       list = NULL;
+               }
+               yaffs_trace(YAFFS_TRACE_ALLOCATE,
+                       "Could not allocate more objects");
+               return YAFFS_FAIL;
+       }
+
+       /* Hook them into the free list */
+       for (i = 0; i < n_obj - 1; i++) {
+               new_objs[i].siblings.next =
+                   (struct list_head *)(&new_objs[i + 1]);
+       }
+
+       new_objs[n_obj - 1].siblings.next = (void *)allocator->free_objs;
+       allocator->free_objs = new_objs;
+       allocator->n_free_objects += n_obj;
+       allocator->n_obj_created += n_obj;
+
+       /* Now add this bunch of Objects to a list for freeing up. */
+
+       list->objects = new_objs;
+       list->next = allocator->allocated_obj_list;
+       allocator->allocated_obj_list = list;
+
+       return YAFFS_OK;
+}
+
+struct yaffs_obj *yaffs_alloc_raw_obj(struct yaffs_dev *dev)
+{
+       struct yaffs_obj *obj = NULL;
+       struct yaffs_allocator *allocator = dev->allocator;
+
+       if (!allocator) {
+               YBUG();
+               return obj;
+       }
+
+       /* If there are none left make more */
+       if (!allocator->free_objs)
+               yaffs_create_free_objs(dev, YAFFS_ALLOCATION_NOBJECTS);
+
+       if (allocator->free_objs) {
+               obj = allocator->free_objs;
+               allocator->free_objs =
+                   (struct yaffs_obj *)(allocator->free_objs->siblings.next);
+               allocator->n_free_objects--;
+       }
+
+       return obj;
+}
+
+void yaffs_free_raw_obj(struct yaffs_dev *dev, struct yaffs_obj *obj)
+{
+
+       struct yaffs_allocator *allocator = dev->allocator;
+
+       if (!allocator)
+               YBUG();
+       else {
+               /* Link into the free list. */
+               obj->siblings.next = (struct list_head *)(allocator->free_objs);
+               allocator->free_objs = obj;
+               allocator->n_free_objects++;
+       }
+}
+
+void yaffs_deinit_raw_tnodes_and_objs(struct yaffs_dev *dev)
+{
+       if (dev->allocator) {
+               yaffs_deinit_raw_tnodes(dev);
+               yaffs_deinit_raw_objs(dev);
+
+               kfree(dev->allocator);
+               dev->allocator = NULL;
+       } else {
+               YBUG();
+       }
+}
+
+void yaffs_init_raw_tnodes_and_objs(struct yaffs_dev *dev)
+{
+       struct yaffs_allocator *allocator;
+
+       if (!dev->allocator) {
+               allocator = kmalloc(sizeof(struct yaffs_allocator), GFP_NOFS);
+               if (allocator) {
+                       dev->allocator = allocator;
+                       yaffs_init_raw_tnodes(dev);
+                       yaffs_init_raw_objs(dev);
+               }
+       } else {
+               YBUG();
+       }
+}
+
+#endif
diff --git a/fs/yaffs2/yaffs_allocator.h b/fs/yaffs2/yaffs_allocator.h
new file mode 100644 (file)
index 0000000..4d5f2ae
--- /dev/null
@@ -0,0 +1,30 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_ALLOCATOR_H__
+#define __YAFFS_ALLOCATOR_H__
+
+#include "yaffs_guts.h"
+
+void yaffs_init_raw_tnodes_and_objs(struct yaffs_dev *dev);
+void yaffs_deinit_raw_tnodes_and_objs(struct yaffs_dev *dev);
+
+struct yaffs_tnode *yaffs_alloc_raw_tnode(struct yaffs_dev *dev);
+void yaffs_free_raw_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn);
+
+struct yaffs_obj *yaffs_alloc_raw_obj(struct yaffs_dev *dev);
+void yaffs_free_raw_obj(struct yaffs_dev *dev, struct yaffs_obj *obj);
+
+#endif
diff --git a/fs/yaffs2/yaffs_attribs.c b/fs/yaffs2/yaffs_attribs.c
new file mode 100644 (file)
index 0000000..9b47d37
--- /dev/null
@@ -0,0 +1,124 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_guts.h"
+#include "yaffs_attribs.h"
+
+void yaffs_load_attribs(struct yaffs_obj *obj, struct yaffs_obj_hdr *oh)
+{
+       obj->yst_uid = oh->yst_uid;
+       obj->yst_gid = oh->yst_gid;
+       obj->yst_atime = oh->yst_atime;
+       obj->yst_mtime = oh->yst_mtime;
+       obj->yst_ctime = oh->yst_ctime;
+       obj->yst_rdev = oh->yst_rdev;
+}
+
+void yaffs_load_attribs_oh(struct yaffs_obj_hdr *oh, struct yaffs_obj *obj)
+{
+       oh->yst_uid = obj->yst_uid;
+       oh->yst_gid = obj->yst_gid;
+       oh->yst_atime = obj->yst_atime;
+       oh->yst_mtime = obj->yst_mtime;
+       oh->yst_ctime = obj->yst_ctime;
+       oh->yst_rdev = obj->yst_rdev;
+
+}
+
+void yaffs_load_current_time(struct yaffs_obj *obj, int do_a, int do_c)
+{
+       obj->yst_mtime = Y_CURRENT_TIME;
+       if (do_a)
+               obj->yst_atime = obj->yst_mtime;
+       if (do_c)
+               obj->yst_ctime = obj->yst_mtime;
+}
+
+void yaffs_attribs_init(struct yaffs_obj *obj, u32 gid, u32 uid, u32 rdev)
+{
+       yaffs_load_current_time(obj, 1, 1);
+       obj->yst_rdev = rdev;
+       obj->yst_uid = uid;
+       obj->yst_gid = gid;
+}
+
+loff_t yaffs_get_file_size(struct yaffs_obj *obj)
+{
+       YCHAR *alias = NULL;
+       obj = yaffs_get_equivalent_obj(obj);
+
+       switch (obj->variant_type) {
+       case YAFFS_OBJECT_TYPE_FILE:
+               return obj->variant.file_variant.file_size;
+       case YAFFS_OBJECT_TYPE_SYMLINK:
+               alias = obj->variant.symlink_variant.alias;
+               if (!alias)
+                       return 0;
+               return strnlen(alias, YAFFS_MAX_ALIAS_LENGTH);
+       default:
+               return 0;
+       }
+}
+
+int yaffs_set_attribs(struct yaffs_obj *obj, struct iattr *attr)
+{
+       unsigned int valid = attr->ia_valid;
+
+       if (valid & ATTR_MODE)
+               obj->yst_mode = attr->ia_mode;
+       if (valid & ATTR_UID)
+               obj->yst_uid = attr->ia_uid;
+       if (valid & ATTR_GID)
+               obj->yst_gid = attr->ia_gid;
+
+       if (valid & ATTR_ATIME)
+               obj->yst_atime = Y_TIME_CONVERT(attr->ia_atime);
+       if (valid & ATTR_CTIME)
+               obj->yst_ctime = Y_TIME_CONVERT(attr->ia_ctime);
+       if (valid & ATTR_MTIME)
+               obj->yst_mtime = Y_TIME_CONVERT(attr->ia_mtime);
+
+       if (valid & ATTR_SIZE)
+               yaffs_resize_file(obj, attr->ia_size);
+
+       yaffs_update_oh(obj, NULL, 1, 0, 0, NULL);
+
+       return YAFFS_OK;
+
+}
+
+int yaffs_get_attribs(struct yaffs_obj *obj, struct iattr *attr)
+{
+       unsigned int valid = 0;
+
+       attr->ia_mode = obj->yst_mode;
+       valid |= ATTR_MODE;
+       attr->ia_uid = obj->yst_uid;
+       valid |= ATTR_UID;
+       attr->ia_gid = obj->yst_gid;
+       valid |= ATTR_GID;
+
+       Y_TIME_CONVERT(attr->ia_atime) = obj->yst_atime;
+       valid |= ATTR_ATIME;
+       Y_TIME_CONVERT(attr->ia_ctime) = obj->yst_ctime;
+       valid |= ATTR_CTIME;
+       Y_TIME_CONVERT(attr->ia_mtime) = obj->yst_mtime;
+       valid |= ATTR_MTIME;
+
+       attr->ia_size = yaffs_get_file_size(obj);
+       valid |= ATTR_SIZE;
+
+       attr->ia_valid = valid;
+
+       return YAFFS_OK;
+}
diff --git a/fs/yaffs2/yaffs_attribs.h b/fs/yaffs2/yaffs_attribs.h
new file mode 100644 (file)
index 0000000..33d541d
--- /dev/null
@@ -0,0 +1,28 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_ATTRIBS_H__
+#define __YAFFS_ATTRIBS_H__
+
+#include "yaffs_guts.h"
+
+void yaffs_load_attribs(struct yaffs_obj *obj, struct yaffs_obj_hdr *oh);
+void yaffs_load_attribs_oh(struct yaffs_obj_hdr *oh, struct yaffs_obj *obj);
+void yaffs_attribs_init(struct yaffs_obj *obj, u32 gid, u32 uid, u32 rdev);
+void yaffs_load_current_time(struct yaffs_obj *obj, int do_a, int do_c);
+int yaffs_set_attribs(struct yaffs_obj *obj, struct iattr *attr);
+int yaffs_get_attribs(struct yaffs_obj *obj, struct iattr *attr);
+
+#endif
diff --git a/fs/yaffs2/yaffs_bitmap.c b/fs/yaffs2/yaffs_bitmap.c
new file mode 100644 (file)
index 0000000..7df42cd
--- /dev/null
@@ -0,0 +1,98 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_bitmap.h"
+#include "yaffs_trace.h"
+/*
+ * Chunk bitmap manipulations
+ */
+
+static inline u8 *yaffs_block_bits(struct yaffs_dev *dev, int blk)
+{
+       if (blk < dev->internal_start_block || blk > dev->internal_end_block) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                       "BlockBits block %d is not valid",
+                       blk);
+               YBUG();
+       }
+       return dev->chunk_bits +
+           (dev->chunk_bit_stride * (blk - dev->internal_start_block));
+}
+
+void yaffs_verify_chunk_bit_id(struct yaffs_dev *dev, int blk, int chunk)
+{
+       if (blk < dev->internal_start_block || blk > dev->internal_end_block ||
+           chunk < 0 || chunk >= dev->param.chunks_per_block) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                       "Chunk Id (%d:%d) invalid",
+                       blk, chunk);
+               YBUG();
+       }
+}
+
+void yaffs_clear_chunk_bits(struct yaffs_dev *dev, int blk)
+{
+       u8 *blk_bits = yaffs_block_bits(dev, blk);
+
+       memset(blk_bits, 0, dev->chunk_bit_stride);
+}
+
+void yaffs_clear_chunk_bit(struct yaffs_dev *dev, int blk, int chunk)
+{
+       u8 *blk_bits = yaffs_block_bits(dev, blk);
+
+       yaffs_verify_chunk_bit_id(dev, blk, chunk);
+
+       blk_bits[chunk / 8] &= ~(1 << (chunk & 7));
+}
+
+void yaffs_set_chunk_bit(struct yaffs_dev *dev, int blk, int chunk)
+{
+       u8 *blk_bits = yaffs_block_bits(dev, blk);
+
+       yaffs_verify_chunk_bit_id(dev, blk, chunk);
+
+       blk_bits[chunk / 8] |= (1 << (chunk & 7));
+}
+
+int yaffs_check_chunk_bit(struct yaffs_dev *dev, int blk, int chunk)
+{
+       u8 *blk_bits = yaffs_block_bits(dev, blk);
+       yaffs_verify_chunk_bit_id(dev, blk, chunk);
+
+       return (blk_bits[chunk / 8] & (1 << (chunk & 7))) ? 1 : 0;
+}
+
+int yaffs_still_some_chunks(struct yaffs_dev *dev, int blk)
+{
+       u8 *blk_bits = yaffs_block_bits(dev, blk);
+       int i;
+       for (i = 0; i < dev->chunk_bit_stride; i++) {
+               if (*blk_bits)
+                       return 1;
+               blk_bits++;
+       }
+       return 0;
+}
+
+int yaffs_count_chunk_bits(struct yaffs_dev *dev, int blk)
+{
+       u8 *blk_bits = yaffs_block_bits(dev, blk);
+       int i;
+       int n = 0;
+
+       for (i = 0; i < dev->chunk_bit_stride; i++, blk_bits++)
+               n += hweight8(*blk_bits);
+
+       return n;
+}
diff --git a/fs/yaffs2/yaffs_bitmap.h b/fs/yaffs2/yaffs_bitmap.h
new file mode 100644 (file)
index 0000000..cf9ea58
--- /dev/null
@@ -0,0 +1,33 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+/*
+ * Chunk bitmap manipulations
+ */
+
+#ifndef __YAFFS_BITMAP_H__
+#define __YAFFS_BITMAP_H__
+
+#include "yaffs_guts.h"
+
+void yaffs_verify_chunk_bit_id(struct yaffs_dev *dev, int blk, int chunk);
+void yaffs_clear_chunk_bits(struct yaffs_dev *dev, int blk);
+void yaffs_clear_chunk_bit(struct yaffs_dev *dev, int blk, int chunk);
+void yaffs_set_chunk_bit(struct yaffs_dev *dev, int blk, int chunk);
+int yaffs_check_chunk_bit(struct yaffs_dev *dev, int blk, int chunk);
+int yaffs_still_some_chunks(struct yaffs_dev *dev, int blk);
+int yaffs_count_chunk_bits(struct yaffs_dev *dev, int blk);
+
+#endif
diff --git a/fs/yaffs2/yaffs_checkptrw.c b/fs/yaffs2/yaffs_checkptrw.c
new file mode 100644 (file)
index 0000000..4e40f43
--- /dev/null
@@ -0,0 +1,415 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_checkptrw.h"
+#include "yaffs_getblockinfo.h"
+
+static int yaffs2_checkpt_space_ok(struct yaffs_dev *dev)
+{
+       int blocks_avail = dev->n_erased_blocks - dev->param.n_reserved_blocks;
+
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+               "checkpt blocks_avail = %d", blocks_avail);
+
+       return (blocks_avail <= 0) ? 0 : 1;
+}
+
+static int yaffs_checkpt_erase(struct yaffs_dev *dev)
+{
+       int i;
+
+       if (!dev->param.erase_fn)
+               return 0;
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+               "checking blocks %d to %d",
+               dev->internal_start_block, dev->internal_end_block);
+
+       for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
+               struct yaffs_block_info *bi = yaffs_get_block_info(dev, i);
+               if (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT) {
+                       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                       "erasing checkpt block %d", i);
+
+                       dev->n_erasures++;
+
+                       if (dev->param.
+                           erase_fn(dev,
+                                    i - dev->block_offset /* realign */ )) {
+                               bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
+                               dev->n_erased_blocks++;
+                               dev->n_free_chunks +=
+                                   dev->param.chunks_per_block;
+                       } else {
+                               dev->param.bad_block_fn(dev, i);
+                               bi->block_state = YAFFS_BLOCK_STATE_DEAD;
+                       }
+               }
+       }
+
+       dev->blocks_in_checkpt = 0;
+
+       return 1;
+}
+
+static void yaffs2_checkpt_find_erased_block(struct yaffs_dev *dev)
+{
+       int i;
+       int blocks_avail = dev->n_erased_blocks - dev->param.n_reserved_blocks;
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+               "allocating checkpt block: erased %d reserved %d avail %d next %d ",
+               dev->n_erased_blocks, dev->param.n_reserved_blocks,
+               blocks_avail, dev->checkpt_next_block);
+
+       if (dev->checkpt_next_block >= 0 &&
+           dev->checkpt_next_block <= dev->internal_end_block &&
+           blocks_avail > 0) {
+
+               for (i = dev->checkpt_next_block; i <= dev->internal_end_block;
+                    i++) {
+                       struct yaffs_block_info *bi =
+                           yaffs_get_block_info(dev, i);
+                       if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
+                               dev->checkpt_next_block = i + 1;
+                               dev->checkpt_cur_block = i;
+                               yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                                       "allocating checkpt block %d", i);
+                               return;
+                       }
+               }
+       }
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT, "out of checkpt blocks");
+
+       dev->checkpt_next_block = -1;
+       dev->checkpt_cur_block = -1;
+}
+
+static void yaffs2_checkpt_find_block(struct yaffs_dev *dev)
+{
+       int i;
+       struct yaffs_ext_tags tags;
+
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+               "find next checkpt block: start:  blocks %d next %d",
+               dev->blocks_in_checkpt, dev->checkpt_next_block);
+
+       if (dev->blocks_in_checkpt < dev->checkpt_max_blocks)
+               for (i = dev->checkpt_next_block; i <= dev->internal_end_block;
+                    i++) {
+                       int chunk = i * dev->param.chunks_per_block;
+                       int realigned_chunk = chunk - dev->chunk_offset;
+
+                       dev->param.read_chunk_tags_fn(dev, realigned_chunk,
+                                                     NULL, &tags);
+                       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                               "find next checkpt block: search: block %d oid %d seq %d eccr %d",
+                               i, tags.obj_id, tags.seq_number,
+                               tags.ecc_result);
+
+                       if (tags.seq_number == YAFFS_SEQUENCE_CHECKPOINT_DATA) {
+                               /* Right kind of block */
+                               dev->checkpt_next_block = tags.obj_id;
+                               dev->checkpt_cur_block = i;
+                               dev->checkpt_block_list[dev->
+                                                       blocks_in_checkpt] = i;
+                               dev->blocks_in_checkpt++;
+                               yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                                       "found checkpt block %d", i);
+                               return;
+                       }
+               }
+
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT, "found no more checkpt blocks");
+
+       dev->checkpt_next_block = -1;
+       dev->checkpt_cur_block = -1;
+}
+
+int yaffs2_checkpt_open(struct yaffs_dev *dev, int writing)
+{
+
+       dev->checkpt_open_write = writing;
+
+       /* Got the functions we need? */
+       if (!dev->param.write_chunk_tags_fn ||
+           !dev->param.read_chunk_tags_fn ||
+           !dev->param.erase_fn || !dev->param.bad_block_fn)
+               return 0;
+
+       if (writing && !yaffs2_checkpt_space_ok(dev))
+               return 0;
+
+       if (!dev->checkpt_buffer)
+               dev->checkpt_buffer =
+                   kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
+       if (!dev->checkpt_buffer)
+               return 0;
+
+       dev->checkpt_page_seq = 0;
+       dev->checkpt_byte_count = 0;
+       dev->checkpt_sum = 0;
+       dev->checkpt_xor = 0;
+       dev->checkpt_cur_block = -1;
+       dev->checkpt_cur_chunk = -1;
+       dev->checkpt_next_block = dev->internal_start_block;
+
+       /* Erase all the blocks in the checkpoint area */
+       if (writing) {
+               memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);
+               dev->checkpt_byte_offs = 0;
+               return yaffs_checkpt_erase(dev);
+       } else {
+               int i;
+               /* Set to a value that will kick off a read */
+               dev->checkpt_byte_offs = dev->data_bytes_per_chunk;
+               /* A checkpoint block list of 1 checkpoint block per 16 block is (hopefully)
+                * going to be way more than we need */
+               dev->blocks_in_checkpt = 0;
+               dev->checkpt_max_blocks =
+                   (dev->internal_end_block - dev->internal_start_block) / 16 +
+                   2;
+               dev->checkpt_block_list =
+                   kmalloc(sizeof(int) * dev->checkpt_max_blocks, GFP_NOFS);
+               if (!dev->checkpt_block_list)
+                       return 0;
+
+               for (i = 0; i < dev->checkpt_max_blocks; i++)
+                       dev->checkpt_block_list[i] = -1;
+       }
+
+       return 1;
+}
+
+int yaffs2_get_checkpt_sum(struct yaffs_dev *dev, u32 * sum)
+{
+       u32 composite_sum;
+       composite_sum = (dev->checkpt_sum << 8) | (dev->checkpt_xor & 0xFF);
+       *sum = composite_sum;
+       return 1;
+}
+
+static int yaffs2_checkpt_flush_buffer(struct yaffs_dev *dev)
+{
+       int chunk;
+       int realigned_chunk;
+
+       struct yaffs_ext_tags tags;
+
+       if (dev->checkpt_cur_block < 0) {
+               yaffs2_checkpt_find_erased_block(dev);
+               dev->checkpt_cur_chunk = 0;
+       }
+
+       if (dev->checkpt_cur_block < 0)
+               return 0;
+
+       tags.is_deleted = 0;
+       tags.obj_id = dev->checkpt_next_block;  /* Hint to next place to look */
+       tags.chunk_id = dev->checkpt_page_seq + 1;
+       tags.seq_number = YAFFS_SEQUENCE_CHECKPOINT_DATA;
+       tags.n_bytes = dev->data_bytes_per_chunk;
+       if (dev->checkpt_cur_chunk == 0) {
+               /* First chunk we write for the block? Set block state to
+                  checkpoint */
+               struct yaffs_block_info *bi =
+                   yaffs_get_block_info(dev, dev->checkpt_cur_block);
+               bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
+               dev->blocks_in_checkpt++;
+       }
+
+       chunk =
+           dev->checkpt_cur_block * dev->param.chunks_per_block +
+           dev->checkpt_cur_chunk;
+
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+               "checkpoint wite buffer nand %d(%d:%d) objid %d chId %d",
+               chunk, dev->checkpt_cur_block, dev->checkpt_cur_chunk,
+               tags.obj_id, tags.chunk_id);
+
+       realigned_chunk = chunk - dev->chunk_offset;
+
+       dev->n_page_writes++;
+
+       dev->param.write_chunk_tags_fn(dev, realigned_chunk,
+                                      dev->checkpt_buffer, &tags);
+       dev->checkpt_byte_offs = 0;
+       dev->checkpt_page_seq++;
+       dev->checkpt_cur_chunk++;
+       if (dev->checkpt_cur_chunk >= dev->param.chunks_per_block) {
+               dev->checkpt_cur_chunk = 0;
+               dev->checkpt_cur_block = -1;
+       }
+       memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);
+
+       return 1;
+}
+
+int yaffs2_checkpt_wr(struct yaffs_dev *dev, const void *data, int n_bytes)
+{
+       int i = 0;
+       int ok = 1;
+
+       u8 *data_bytes = (u8 *) data;
+
+       if (!dev->checkpt_buffer)
+               return 0;
+
+       if (!dev->checkpt_open_write)
+               return -1;
+
+       while (i < n_bytes && ok) {
+               dev->checkpt_buffer[dev->checkpt_byte_offs] = *data_bytes;
+               dev->checkpt_sum += *data_bytes;
+               dev->checkpt_xor ^= *data_bytes;
+
+               dev->checkpt_byte_offs++;
+               i++;
+               data_bytes++;
+               dev->checkpt_byte_count++;
+
+               if (dev->checkpt_byte_offs < 0 ||
+                   dev->checkpt_byte_offs >= dev->data_bytes_per_chunk)
+                       ok = yaffs2_checkpt_flush_buffer(dev);
+       }
+
+       return i;
+}
+
+int yaffs2_checkpt_rd(struct yaffs_dev *dev, void *data, int n_bytes)
+{
+       int i = 0;
+       int ok = 1;
+       struct yaffs_ext_tags tags;
+
+       int chunk;
+       int realigned_chunk;
+
+       u8 *data_bytes = (u8 *) data;
+
+       if (!dev->checkpt_buffer)
+               return 0;
+
+       if (dev->checkpt_open_write)
+               return -1;
+
+       while (i < n_bytes && ok) {
+
+               if (dev->checkpt_byte_offs < 0 ||
+                   dev->checkpt_byte_offs >= dev->data_bytes_per_chunk) {
+
+                       if (dev->checkpt_cur_block < 0) {
+                               yaffs2_checkpt_find_block(dev);
+                               dev->checkpt_cur_chunk = 0;
+                       }
+
+                       if (dev->checkpt_cur_block < 0)
+                               ok = 0;
+                       else {
+                               chunk = dev->checkpt_cur_block *
+                                   dev->param.chunks_per_block +
+                                   dev->checkpt_cur_chunk;
+
+                               realigned_chunk = chunk - dev->chunk_offset;
+
+                               dev->n_page_reads++;
+
+                               /* read in the next chunk */
+                               dev->param.read_chunk_tags_fn(dev,
+                                                             realigned_chunk,
+                                                             dev->
+                                                             checkpt_buffer,
+                                                             &tags);
+
+                               if (tags.chunk_id != (dev->checkpt_page_seq + 1)
+                                   || tags.ecc_result > YAFFS_ECC_RESULT_FIXED
+                                   || tags.seq_number !=
+                                   YAFFS_SEQUENCE_CHECKPOINT_DATA)
+                                       ok = 0;
+
+                               dev->checkpt_byte_offs = 0;
+                               dev->checkpt_page_seq++;
+                               dev->checkpt_cur_chunk++;
+
+                               if (dev->checkpt_cur_chunk >=
+                                   dev->param.chunks_per_block)
+                                       dev->checkpt_cur_block = -1;
+                       }
+               }
+
+               if (ok) {
+                       *data_bytes =
+                           dev->checkpt_buffer[dev->checkpt_byte_offs];
+                       dev->checkpt_sum += *data_bytes;
+                       dev->checkpt_xor ^= *data_bytes;
+                       dev->checkpt_byte_offs++;
+                       i++;
+                       data_bytes++;
+                       dev->checkpt_byte_count++;
+               }
+       }
+
+       return i;
+}
+
+int yaffs_checkpt_close(struct yaffs_dev *dev)
+{
+
+       if (dev->checkpt_open_write) {
+               if (dev->checkpt_byte_offs != 0)
+                       yaffs2_checkpt_flush_buffer(dev);
+       } else if (dev->checkpt_block_list) {
+               int i;
+               for (i = 0;
+                    i < dev->blocks_in_checkpt
+                    && dev->checkpt_block_list[i] >= 0; i++) {
+                       int blk = dev->checkpt_block_list[i];
+                       struct yaffs_block_info *bi = NULL;
+                       if (dev->internal_start_block <= blk
+                           && blk <= dev->internal_end_block)
+                               bi = yaffs_get_block_info(dev, blk);
+                       if (bi && bi->block_state == YAFFS_BLOCK_STATE_EMPTY)
+                               bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
+                       else {
+                               /* Todo this looks odd... */
+                       }
+               }
+               kfree(dev->checkpt_block_list);
+               dev->checkpt_block_list = NULL;
+       }
+
+       dev->n_free_chunks -=
+           dev->blocks_in_checkpt * dev->param.chunks_per_block;
+       dev->n_erased_blocks -= dev->blocks_in_checkpt;
+
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT,"checkpoint byte count %d",
+               dev->checkpt_byte_count);
+
+       if (dev->checkpt_buffer) {
+               /* free the buffer */
+               kfree(dev->checkpt_buffer);
+               dev->checkpt_buffer = NULL;
+               return 1;
+       } else {
+               return 0;
+        }
+}
+
+int yaffs2_checkpt_invalidate_stream(struct yaffs_dev *dev)
+{
+       /* Erase the checkpoint data */
+
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+               "checkpoint invalidate of %d blocks",
+               dev->blocks_in_checkpt);
+
+       return yaffs_checkpt_erase(dev);
+}
diff --git a/fs/yaffs2/yaffs_checkptrw.h b/fs/yaffs2/yaffs_checkptrw.h
new file mode 100644 (file)
index 0000000..361c606
--- /dev/null
@@ -0,0 +1,33 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_CHECKPTRW_H__
+#define __YAFFS_CHECKPTRW_H__
+
+#include "yaffs_guts.h"
+
+int yaffs2_checkpt_open(struct yaffs_dev *dev, int writing);
+
+int yaffs2_checkpt_wr(struct yaffs_dev *dev, const void *data, int n_bytes);
+
+int yaffs2_checkpt_rd(struct yaffs_dev *dev, void *data, int n_bytes);
+
+int yaffs2_get_checkpt_sum(struct yaffs_dev *dev, u32 * sum);
+
+int yaffs_checkpt_close(struct yaffs_dev *dev);
+
+int yaffs2_checkpt_invalidate_stream(struct yaffs_dev *dev);
+
+#endif
diff --git a/fs/yaffs2/yaffs_ecc.c b/fs/yaffs2/yaffs_ecc.c
new file mode 100644 (file)
index 0000000..e95a806
--- /dev/null
@@ -0,0 +1,298 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * This code implements the ECC algorithm used in SmartMedia.
+ *
+ * The ECC comprises 22 bits of parity information and is stuffed into 3 bytes.
+ * The two unused bit are set to 1.
+ * The ECC can correct single bit errors in a 256-byte page of data. Thus, two such ECC
+ * blocks are used on a 512-byte NAND page.
+ *
+ */
+
+/* Table generated by gen-ecc.c
+ * Using a table means we do not have to calculate p1..p4 and p1'..p4'
+ * for each byte of data. These are instead provided in a table in bits7..2.
+ * Bit 0 of each entry indicates whether the entry has an odd or even parity, and therefore
+ * this bytes influence on the line parity.
+ */
+
+#include "yportenv.h"
+
+#include "yaffs_ecc.h"
+
+static const unsigned char column_parity_table[] = {
+       0x00, 0x55, 0x59, 0x0c, 0x65, 0x30, 0x3c, 0x69,
+       0x69, 0x3c, 0x30, 0x65, 0x0c, 0x59, 0x55, 0x00,
+       0x95, 0xc0, 0xcc, 0x99, 0xf0, 0xa5, 0xa9, 0xfc,
+       0xfc, 0xa9, 0xa5, 0xf0, 0x99, 0xcc, 0xc0, 0x95,
+       0x99, 0xcc, 0xc0, 0x95, 0xfc, 0xa9, 0xa5, 0xf0,
+       0xf0, 0xa5, 0xa9, 0xfc, 0x95, 0xc0, 0xcc, 0x99,
+       0x0c, 0x59, 0x55, 0x00, 0x69, 0x3c, 0x30, 0x65,
+       0x65, 0x30, 0x3c, 0x69, 0x00, 0x55, 0x59, 0x0c,
+       0xa5, 0xf0, 0xfc, 0xa9, 0xc0, 0x95, 0x99, 0xcc,
+       0xcc, 0x99, 0x95, 0xc0, 0xa9, 0xfc, 0xf0, 0xa5,
+       0x30, 0x65, 0x69, 0x3c, 0x55, 0x00, 0x0c, 0x59,
+       0x59, 0x0c, 0x00, 0x55, 0x3c, 0x69, 0x65, 0x30,
+       0x3c, 0x69, 0x65, 0x30, 0x59, 0x0c, 0x00, 0x55,
+       0x55, 0x00, 0x0c, 0x59, 0x30, 0x65, 0x69, 0x3c,
+       0xa9, 0xfc, 0xf0, 0xa5, 0xcc, 0x99, 0x95, 0xc0,
+       0xc0, 0x95, 0x99, 0xcc, 0xa5, 0xf0, 0xfc, 0xa9,
+       0xa9, 0xfc, 0xf0, 0xa5, 0xcc, 0x99, 0x95, 0xc0,
+       0xc0, 0x95, 0x99, 0xcc, 0xa5, 0xf0, 0xfc, 0xa9,
+       0x3c, 0x69, 0x65, 0x30, 0x59, 0x0c, 0x00, 0x55,
+       0x55, 0x00, 0x0c, 0x59, 0x30, 0x65, 0x69, 0x3c,
+       0x30, 0x65, 0x69, 0x3c, 0x55, 0x00, 0x0c, 0x59,
+       0x59, 0x0c, 0x00, 0x55, 0x3c, 0x69, 0x65, 0x30,
+       0xa5, 0xf0, 0xfc, 0xa9, 0xc0, 0x95, 0x99, 0xcc,
+       0xcc, 0x99, 0x95, 0xc0, 0xa9, 0xfc, 0xf0, 0xa5,
+       0x0c, 0x59, 0x55, 0x00, 0x69, 0x3c, 0x30, 0x65,
+       0x65, 0x30, 0x3c, 0x69, 0x00, 0x55, 0x59, 0x0c,
+       0x99, 0xcc, 0xc0, 0x95, 0xfc, 0xa9, 0xa5, 0xf0,
+       0xf0, 0xa5, 0xa9, 0xfc, 0x95, 0xc0, 0xcc, 0x99,
+       0x95, 0xc0, 0xcc, 0x99, 0xf0, 0xa5, 0xa9, 0xfc,
+       0xfc, 0xa9, 0xa5, 0xf0, 0x99, 0xcc, 0xc0, 0x95,
+       0x00, 0x55, 0x59, 0x0c, 0x65, 0x30, 0x3c, 0x69,
+       0x69, 0x3c, 0x30, 0x65, 0x0c, 0x59, 0x55, 0x00,
+};
+
+
+/* Calculate the ECC for a 256-byte block of data */
+void yaffs_ecc_cacl(const unsigned char *data, unsigned char *ecc)
+{
+       unsigned int i;
+
+       unsigned char col_parity = 0;
+       unsigned char line_parity = 0;
+       unsigned char line_parity_prime = 0;
+       unsigned char t;
+       unsigned char b;
+
+       for (i = 0; i < 256; i++) {
+               b = column_parity_table[*data++];
+               col_parity ^= b;
+
+               if (b & 0x01) { /* odd number of bits in the byte */
+                       line_parity ^= i;
+                       line_parity_prime ^= ~i;
+               }
+       }
+
+       ecc[2] = (~col_parity) | 0x03;
+
+       t = 0;
+       if (line_parity & 0x80)
+               t |= 0x80;
+       if (line_parity_prime & 0x80)
+               t |= 0x40;
+       if (line_parity & 0x40)
+               t |= 0x20;
+       if (line_parity_prime & 0x40)
+               t |= 0x10;
+       if (line_parity & 0x20)
+               t |= 0x08;
+       if (line_parity_prime & 0x20)
+               t |= 0x04;
+       if (line_parity & 0x10)
+               t |= 0x02;
+       if (line_parity_prime & 0x10)
+               t |= 0x01;
+       ecc[1] = ~t;
+
+       t = 0;
+       if (line_parity & 0x08)
+               t |= 0x80;
+       if (line_parity_prime & 0x08)
+               t |= 0x40;
+       if (line_parity & 0x04)
+               t |= 0x20;
+       if (line_parity_prime & 0x04)
+               t |= 0x10;
+       if (line_parity & 0x02)
+               t |= 0x08;
+       if (line_parity_prime & 0x02)
+               t |= 0x04;
+       if (line_parity & 0x01)
+               t |= 0x02;
+       if (line_parity_prime & 0x01)
+               t |= 0x01;
+       ecc[0] = ~t;
+
+#ifdef CONFIG_YAFFS_ECC_WRONG_ORDER
+       /* Swap the bytes into the wrong order */
+       t = ecc[0];
+       ecc[0] = ecc[1];
+       ecc[1] = t;
+#endif
+}
+
+/* Correct the ECC on a 256 byte block of data */
+
+int yaffs_ecc_correct(unsigned char *data, unsigned char *read_ecc,
+                     const unsigned char *test_ecc)
+{
+       unsigned char d0, d1, d2;       /* deltas */
+
+       d0 = read_ecc[0] ^ test_ecc[0];
+       d1 = read_ecc[1] ^ test_ecc[1];
+       d2 = read_ecc[2] ^ test_ecc[2];
+
+       if ((d0 | d1 | d2) == 0)
+               return 0;       /* no error */
+
+       if (((d0 ^ (d0 >> 1)) & 0x55) == 0x55 &&
+           ((d1 ^ (d1 >> 1)) & 0x55) == 0x55 &&
+           ((d2 ^ (d2 >> 1)) & 0x54) == 0x54) {
+               /* Single bit (recoverable) error in data */
+
+               unsigned byte;
+               unsigned bit;
+
+#ifdef CONFIG_YAFFS_ECC_WRONG_ORDER
+               /* swap the bytes to correct for the wrong order */
+               unsigned char t;
+
+               t = d0;
+               d0 = d1;
+               d1 = t;
+#endif
+
+               bit = byte = 0;
+
+               if (d1 & 0x80)
+                       byte |= 0x80;
+               if (d1 & 0x20)
+                       byte |= 0x40;
+               if (d1 & 0x08)
+                       byte |= 0x20;
+               if (d1 & 0x02)
+                       byte |= 0x10;
+               if (d0 & 0x80)
+                       byte |= 0x08;
+               if (d0 & 0x20)
+                       byte |= 0x04;
+               if (d0 & 0x08)
+                       byte |= 0x02;
+               if (d0 & 0x02)
+                       byte |= 0x01;
+
+               if (d2 & 0x80)
+                       bit |= 0x04;
+               if (d2 & 0x20)
+                       bit |= 0x02;
+               if (d2 & 0x08)
+                       bit |= 0x01;
+
+               data[byte] ^= (1 << bit);
+
+               return 1;       /* Corrected the error */
+       }
+
+       if ((hweight8(d0) + hweight8(d1) + hweight8(d2)) == 1) {
+               /* Reccoverable error in ecc */
+
+               read_ecc[0] = test_ecc[0];
+               read_ecc[1] = test_ecc[1];
+               read_ecc[2] = test_ecc[2];
+
+               return 1;       /* Corrected the error */
+       }
+
+       /* Unrecoverable error */
+
+       return -1;
+
+}
+
+/*
+ * ECCxxxOther does ECC calcs on arbitrary n bytes of data
+ */
+void yaffs_ecc_calc_other(const unsigned char *data, unsigned n_bytes,
+                         struct yaffs_ecc_other *ecc_other)
+{
+       unsigned int i;
+
+       unsigned char col_parity = 0;
+       unsigned line_parity = 0;
+       unsigned line_parity_prime = 0;
+       unsigned char b;
+
+       for (i = 0; i < n_bytes; i++) {
+               b = column_parity_table[*data++];
+               col_parity ^= b;
+
+               if (b & 0x01) {
+                       /* odd number of bits in the byte */
+                       line_parity ^= i;
+                       line_parity_prime ^= ~i;
+               }
+
+       }
+
+       ecc_other->col_parity = (col_parity >> 2) & 0x3f;
+       ecc_other->line_parity = line_parity;
+       ecc_other->line_parity_prime = line_parity_prime;
+}
+
+int yaffs_ecc_correct_other(unsigned char *data, unsigned n_bytes,
+                           struct yaffs_ecc_other *read_ecc,
+                           const struct yaffs_ecc_other *test_ecc)
+{
+       unsigned char delta_col;        /* column parity delta */
+       unsigned delta_line;    /* line parity delta */
+       unsigned delta_line_prime;      /* line parity delta */
+       unsigned bit;
+
+       delta_col = read_ecc->col_parity ^ test_ecc->col_parity;
+       delta_line = read_ecc->line_parity ^ test_ecc->line_parity;
+       delta_line_prime =
+           read_ecc->line_parity_prime ^ test_ecc->line_parity_prime;
+
+       if ((delta_col | delta_line | delta_line_prime) == 0)
+               return 0;       /* no error */
+
+       if (delta_line == ~delta_line_prime &&
+           (((delta_col ^ (delta_col >> 1)) & 0x15) == 0x15)) {
+               /* Single bit (recoverable) error in data */
+
+               bit = 0;
+
+               if (delta_col & 0x20)
+                       bit |= 0x04;
+               if (delta_col & 0x08)
+                       bit |= 0x02;
+               if (delta_col & 0x02)
+                       bit |= 0x01;
+
+               if (delta_line >= n_bytes)
+                       return -1;
+
+               data[delta_line] ^= (1 << bit);
+
+               return 1;       /* corrected */
+       }
+
+       if ((hweight32(delta_line) +
+            hweight32(delta_line_prime) +
+            hweight8(delta_col)) == 1) {
+               /* Reccoverable error in ecc */
+
+               *read_ecc = *test_ecc;
+               return 1;       /* corrected */
+       }
+
+       /* Unrecoverable error */
+
+       return -1;
+}
diff --git a/fs/yaffs2/yaffs_ecc.h b/fs/yaffs2/yaffs_ecc.h
new file mode 100644 (file)
index 0000000..b0c461d
--- /dev/null
@@ -0,0 +1,44 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+/*
+ * This code implements the ECC algorithm used in SmartMedia.
+ *
+ * The ECC comprises 22 bits of parity information and is stuffed into 3 bytes.
+ * The two unused bit are set to 1.
+ * The ECC can correct single bit errors in a 256-byte page of data. Thus, two such ECC
+ * blocks are used on a 512-byte NAND page.
+ *
+ */
+
+#ifndef __YAFFS_ECC_H__
+#define __YAFFS_ECC_H__
+
+struct yaffs_ecc_other {
+       unsigned char col_parity;
+       unsigned line_parity;
+       unsigned line_parity_prime;
+};
+
+void yaffs_ecc_cacl(const unsigned char *data, unsigned char *ecc);
+int yaffs_ecc_correct(unsigned char *data, unsigned char *read_ecc,
+                     const unsigned char *test_ecc);
+
+void yaffs_ecc_calc_other(const unsigned char *data, unsigned n_bytes,
+                         struct yaffs_ecc_other *ecc);
+int yaffs_ecc_correct_other(unsigned char *data, unsigned n_bytes,
+                           struct yaffs_ecc_other *read_ecc,
+                           const struct yaffs_ecc_other *test_ecc);
+#endif
diff --git a/fs/yaffs2/yaffs_getblockinfo.h b/fs/yaffs2/yaffs_getblockinfo.h
new file mode 100644 (file)
index 0000000..d87acbd
--- /dev/null
@@ -0,0 +1,35 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_GETBLOCKINFO_H__
+#define __YAFFS_GETBLOCKINFO_H__
+
+#include "yaffs_guts.h"
+#include "yaffs_trace.h"
+
+/* Function to manipulate block info */
+static inline struct yaffs_block_info *yaffs_get_block_info(struct yaffs_dev
+                                                             *dev, int blk)
+{
+       if (blk < dev->internal_start_block || blk > dev->internal_end_block) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                       "**>> yaffs: get_block_info block %d is not valid",
+                       blk);
+               YBUG();
+       }
+       return &dev->block_info[blk - dev->internal_start_block];
+}
+
+#endif
diff --git a/fs/yaffs2/yaffs_guts.c b/fs/yaffs2/yaffs_guts.c
new file mode 100644 (file)
index 0000000..f4ae9de
--- /dev/null
@@ -0,0 +1,5164 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yportenv.h"
+#include "yaffs_trace.h"
+
+#include "yaffs_guts.h"
+#include "yaffs_tagsvalidity.h"
+#include "yaffs_getblockinfo.h"
+
+#include "yaffs_tagscompat.h"
+
+#include "yaffs_nand.h"
+
+#include "yaffs_yaffs1.h"
+#include "yaffs_yaffs2.h"
+#include "yaffs_bitmap.h"
+#include "yaffs_verify.h"
+
+#include "yaffs_nand.h"
+#include "yaffs_packedtags2.h"
+
+#include "yaffs_nameval.h"
+#include "yaffs_allocator.h"
+
+#include "yaffs_attribs.h"
+
+/* Note YAFFS_GC_GOOD_ENOUGH must be <= YAFFS_GC_PASSIVE_THRESHOLD */
+#define YAFFS_GC_GOOD_ENOUGH 2
+#define YAFFS_GC_PASSIVE_THRESHOLD 4
+
+#include "yaffs_ecc.h"
+
+/* Forward declarations */
+
+static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
+                            const u8 * buffer, int n_bytes, int use_reserve);
+
+
+
+/* Function to calculate chunk and offset */
+
+static void yaffs_addr_to_chunk(struct yaffs_dev *dev, loff_t addr,
+                               int *chunk_out, u32 * offset_out)
+{
+       int chunk;
+       u32 offset;
+
+       chunk = (u32) (addr >> dev->chunk_shift);
+
+       if (dev->chunk_div == 1) {
+               /* easy power of 2 case */
+               offset = (u32) (addr & dev->chunk_mask);
+       } else {
+               /* Non power-of-2 case */
+
+               loff_t chunk_base;
+
+               chunk /= dev->chunk_div;
+
+               chunk_base = ((loff_t) chunk) * dev->data_bytes_per_chunk;
+               offset = (u32) (addr - chunk_base);
+       }
+
+       *chunk_out = chunk;
+       *offset_out = offset;
+}
+
+/* Function to return the number of shifts for a power of 2 greater than or
+ * equal to the given number
+ * Note we don't try to cater for all possible numbers and this does not have to
+ * be hellishly efficient.
+ */
+
+static u32 calc_shifts_ceiling(u32 x)
+{
+       int extra_bits;
+       int shifts;
+
+       shifts = extra_bits = 0;
+
+       while (x > 1) {
+               if (x & 1)
+                       extra_bits++;
+               x >>= 1;
+               shifts++;
+       }
+
+       if (extra_bits)
+               shifts++;
+
+       return shifts;
+}
+
+/* Function to return the number of shifts to get a 1 in bit 0
+ */
+
+static u32 calc_shifts(u32 x)
+{
+       u32 shifts;
+
+       shifts = 0;
+
+       if (!x)
+               return 0;
+
+       while (!(x & 1)) {
+               x >>= 1;
+               shifts++;
+       }
+
+       return shifts;
+}
+
+/*
+ * Temporary buffer manipulations.
+ */
+
+static int yaffs_init_tmp_buffers(struct yaffs_dev *dev)
+{
+       int i;
+       u8 *buf = (u8 *) 1;
+
+       memset(dev->temp_buffer, 0, sizeof(dev->temp_buffer));
+
+       for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) {
+               dev->temp_buffer[i].line = 0;   /* not in use */
+               dev->temp_buffer[i].buffer = buf =
+                   kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
+       }
+
+       return buf ? YAFFS_OK : YAFFS_FAIL;
+}
+
+u8 *yaffs_get_temp_buffer(struct yaffs_dev * dev, int line_no)
+{
+       int i, j;
+
+       dev->temp_in_use++;
+       if (dev->temp_in_use > dev->max_temp)
+               dev->max_temp = dev->temp_in_use;
+
+       for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
+               if (dev->temp_buffer[i].line == 0) {
+                       dev->temp_buffer[i].line = line_no;
+                       if ((i + 1) > dev->max_temp) {
+                               dev->max_temp = i + 1;
+                               for (j = 0; j <= i; j++)
+                                       dev->temp_buffer[j].max_line =
+                                           dev->temp_buffer[j].line;
+                       }
+
+                       return dev->temp_buffer[i].buffer;
+               }
+       }
+
+       yaffs_trace(YAFFS_TRACE_BUFFERS,
+               "Out of temp buffers at line %d, other held by lines:",
+               line_no);
+       for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
+               yaffs_trace(YAFFS_TRACE_BUFFERS," %d", dev->temp_buffer[i].line);
+
+       /*
+        * If we got here then we have to allocate an unmanaged one
+        * This is not good.
+        */
+
+       dev->unmanaged_buffer_allocs++;
+       return kmalloc(dev->data_bytes_per_chunk, GFP_NOFS);
+
+}
+
+void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 * buffer, int line_no)
+{
+       int i;
+
+       dev->temp_in_use--;
+
+       for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
+               if (dev->temp_buffer[i].buffer == buffer) {
+                       dev->temp_buffer[i].line = 0;
+                       return;
+               }
+       }
+
+       if (buffer) {
+               /* assume it is an unmanaged one. */
+               yaffs_trace(YAFFS_TRACE_BUFFERS,
+                 "Releasing unmanaged temp buffer in line %d",
+                  line_no);
+               kfree(buffer);
+               dev->unmanaged_buffer_deallocs++;
+       }
+
+}
+
+/*
+ * Determine if we have a managed buffer.
+ */
+int yaffs_is_managed_tmp_buffer(struct yaffs_dev *dev, const u8 * buffer)
+{
+       int i;
+
+       for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
+               if (dev->temp_buffer[i].buffer == buffer)
+                       return 1;
+       }
+
+       for (i = 0; i < dev->param.n_caches; i++) {
+               if (dev->cache[i].data == buffer)
+                       return 1;
+       }
+
+       if (buffer == dev->checkpt_buffer)
+               return 1;
+
+       yaffs_trace(YAFFS_TRACE_ALWAYS,
+         "yaffs: unmaged buffer detected.");
+       return 0;
+}
+
+/*
+ * Functions for robustisizing TODO
+ *
+ */
+
+static void yaffs_handle_chunk_wr_ok(struct yaffs_dev *dev, int nand_chunk,
+                                    const u8 * data,
+                                    const struct yaffs_ext_tags *tags)
+{
+       dev = dev;
+       nand_chunk = nand_chunk;
+       data = data;
+       tags = tags;
+}
+
+static void yaffs_handle_chunk_update(struct yaffs_dev *dev, int nand_chunk,
+                                     const struct yaffs_ext_tags *tags)
+{
+       dev = dev;
+       nand_chunk = nand_chunk;
+       tags = tags;
+}
+
+void yaffs_handle_chunk_error(struct yaffs_dev *dev,
+                             struct yaffs_block_info *bi)
+{
+       if (!bi->gc_prioritise) {
+               bi->gc_prioritise = 1;
+               dev->has_pending_prioritised_gc = 1;
+               bi->chunk_error_strikes++;
+
+               if (bi->chunk_error_strikes > 3) {
+                       bi->needs_retiring = 1; /* Too many stikes, so retire this */
+                       yaffs_trace(YAFFS_TRACE_ALWAYS, "yaffs: Block struck out");
+
+               }
+       }
+}
+
+static void yaffs_handle_chunk_wr_error(struct yaffs_dev *dev, int nand_chunk,
+                                       int erased_ok)
+{
+       int flash_block = nand_chunk / dev->param.chunks_per_block;
+       struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
+
+       yaffs_handle_chunk_error(dev, bi);
+
+       if (erased_ok) {
+               /* Was an actual write failure, so mark the block for retirement  */
+               bi->needs_retiring = 1;
+               yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
+                 "**>> Block %d needs retiring", flash_block);
+       }
+
+       /* Delete the chunk */
+       yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
+       yaffs_skip_rest_of_block(dev);
+}
+
+/*
+ * Verification code
+ */
+
+/*
+ *  Simple hash function. Needs to have a reasonable spread
+ */
+
+static inline int yaffs_hash_fn(int n)
+{
+       n = abs(n);
+       return n % YAFFS_NOBJECT_BUCKETS;
+}
+
+/*
+ * Access functions to useful fake objects.
+ * Note that root might have a presence in NAND if permissions are set.
+ */
+
+struct yaffs_obj *yaffs_root(struct yaffs_dev *dev)
+{
+       return dev->root_dir;
+}
+
+struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev)
+{
+       return dev->lost_n_found;
+}
+
+/*
+ *  Erased NAND checking functions
+ */
+
+int yaffs_check_ff(u8 * buffer, int n_bytes)
+{
+       /* Horrible, slow implementation */
+       while (n_bytes--) {
+               if (*buffer != 0xFF)
+                       return 0;
+               buffer++;
+       }
+       return 1;
+}
+
+static int yaffs_check_chunk_erased(struct yaffs_dev *dev, int nand_chunk)
+{
+       int retval = YAFFS_OK;
+       u8 *data = yaffs_get_temp_buffer(dev, __LINE__);
+       struct yaffs_ext_tags tags;
+       int result;
+
+       result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, data, &tags);
+
+       if (tags.ecc_result > YAFFS_ECC_RESULT_NO_ERROR)
+               retval = YAFFS_FAIL;
+
+       if (!yaffs_check_ff(data, dev->data_bytes_per_chunk) ||
+               tags.chunk_used) {
+               yaffs_trace(YAFFS_TRACE_NANDACCESS, "Chunk %d not erased", nand_chunk);
+               retval = YAFFS_FAIL;
+       }
+
+       yaffs_release_temp_buffer(dev, data, __LINE__);
+
+       return retval;
+
+}
+
+static int yaffs_verify_chunk_written(struct yaffs_dev *dev,
+                                     int nand_chunk,
+                                     const u8 * data,
+                                     struct yaffs_ext_tags *tags)
+{
+       int retval = YAFFS_OK;
+       struct yaffs_ext_tags temp_tags;
+       u8 *buffer = yaffs_get_temp_buffer(dev, __LINE__);
+       int result;
+
+       result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, buffer, &temp_tags);
+       if (memcmp(buffer, data, dev->data_bytes_per_chunk) ||
+           temp_tags.obj_id != tags->obj_id ||
+           temp_tags.chunk_id != tags->chunk_id ||
+           temp_tags.n_bytes != tags->n_bytes)
+               retval = YAFFS_FAIL;
+
+       yaffs_release_temp_buffer(dev, buffer, __LINE__);
+
+       return retval;
+}
+
+
+int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks)
+{
+       int reserved_chunks;
+       int reserved_blocks = dev->param.n_reserved_blocks;
+       int checkpt_blocks;
+
+       checkpt_blocks = yaffs_calc_checkpt_blocks_required(dev);
+
+       reserved_chunks =
+           ((reserved_blocks + checkpt_blocks) * dev->param.chunks_per_block);
+
+       return (dev->n_free_chunks > (reserved_chunks + n_chunks));
+}
+
+static int yaffs_find_alloc_block(struct yaffs_dev *dev)
+{
+       int i;
+
+       struct yaffs_block_info *bi;
+
+       if (dev->n_erased_blocks < 1) {
+               /* Hoosterman we've got a problem.
+                * Can't get space to gc
+                */
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                 "yaffs tragedy: no more erased blocks" );
+
+               return -1;
+       }
+
+       /* Find an empty block. */
+
+       for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
+               dev->alloc_block_finder++;
+               if (dev->alloc_block_finder < dev->internal_start_block
+                   || dev->alloc_block_finder > dev->internal_end_block) {
+                       dev->alloc_block_finder = dev->internal_start_block;
+               }
+
+               bi = yaffs_get_block_info(dev, dev->alloc_block_finder);
+
+               if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
+                       bi->block_state = YAFFS_BLOCK_STATE_ALLOCATING;
+                       dev->seq_number++;
+                       bi->seq_number = dev->seq_number;
+                       dev->n_erased_blocks--;
+                       yaffs_trace(YAFFS_TRACE_ALLOCATE,
+                         "Allocated block %d, seq  %d, %d left" ,
+                          dev->alloc_block_finder, dev->seq_number,
+                          dev->n_erased_blocks);
+                       return dev->alloc_block_finder;
+               }
+       }
+
+       yaffs_trace(YAFFS_TRACE_ALWAYS,
+               "yaffs tragedy: no more erased blocks, but there should have been %d",
+               dev->n_erased_blocks);
+
+       return -1;
+}
+
+static int yaffs_alloc_chunk(struct yaffs_dev *dev, int use_reserver,
+                            struct yaffs_block_info **block_ptr)
+{
+       int ret_val;
+       struct yaffs_block_info *bi;
+
+       if (dev->alloc_block < 0) {
+               /* Get next block to allocate off */
+               dev->alloc_block = yaffs_find_alloc_block(dev);
+               dev->alloc_page = 0;
+       }
+
+       if (!use_reserver && !yaffs_check_alloc_available(dev, 1)) {
+               /* Not enough space to allocate unless we're allowed to use the reserve. */
+               return -1;
+       }
+
+       if (dev->n_erased_blocks < dev->param.n_reserved_blocks
+           && dev->alloc_page == 0)
+               yaffs_trace(YAFFS_TRACE_ALLOCATE, "Allocating reserve");
+
+       /* Next page please.... */
+       if (dev->alloc_block >= 0) {
+               bi = yaffs_get_block_info(dev, dev->alloc_block);
+
+               ret_val = (dev->alloc_block * dev->param.chunks_per_block) +
+                   dev->alloc_page;
+               bi->pages_in_use++;
+               yaffs_set_chunk_bit(dev, dev->alloc_block, dev->alloc_page);
+
+               dev->alloc_page++;
+
+               dev->n_free_chunks--;
+
+               /* If the block is full set the state to full */
+               if (dev->alloc_page >= dev->param.chunks_per_block) {
+                       bi->block_state = YAFFS_BLOCK_STATE_FULL;
+                       dev->alloc_block = -1;
+               }
+
+               if (block_ptr)
+                       *block_ptr = bi;
+
+               return ret_val;
+       }
+
+       yaffs_trace(YAFFS_TRACE_ERROR, "!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!" );
+
+       return -1;
+}
+
+static int yaffs_get_erased_chunks(struct yaffs_dev *dev)
+{
+       int n;
+
+       n = dev->n_erased_blocks * dev->param.chunks_per_block;
+
+       if (dev->alloc_block > 0)
+               n += (dev->param.chunks_per_block - dev->alloc_page);
+
+       return n;
+
+}
+
+/*
+ * yaffs_skip_rest_of_block() skips over the rest of the allocation block
+ * if we don't want to write to it.
+ */
+void yaffs_skip_rest_of_block(struct yaffs_dev *dev)
+{
+       if (dev->alloc_block > 0) {
+               struct yaffs_block_info *bi =
+                   yaffs_get_block_info(dev, dev->alloc_block);
+               if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING) {
+                       bi->block_state = YAFFS_BLOCK_STATE_FULL;
+                       dev->alloc_block = -1;
+               }
+       }
+}
+
+static int yaffs_write_new_chunk(struct yaffs_dev *dev,
+                                const u8 * data,
+                                struct yaffs_ext_tags *tags, int use_reserver)
+{
+       int attempts = 0;
+       int write_ok = 0;
+       int chunk;
+
+       yaffs2_checkpt_invalidate(dev);
+
+       do {
+               struct yaffs_block_info *bi = 0;
+               int erased_ok = 0;
+
+               chunk = yaffs_alloc_chunk(dev, use_reserver, &bi);
+               if (chunk < 0) {
+                       /* no space */
+                       break;
+               }
+
+               /* First check this chunk is erased, if it needs
+                * checking.  The checking policy (unless forced
+                * always on) is as follows:
+                *
+                * Check the first page we try to write in a block.
+                * If the check passes then we don't need to check any
+                * more.        If the check fails, we check again...
+                * If the block has been erased, we don't need to check.
+                *
+                * However, if the block has been prioritised for gc,
+                * then we think there might be something odd about
+                * this block and stop using it.
+                *
+                * Rationale: We should only ever see chunks that have
+                * not been erased if there was a partially written
+                * chunk due to power loss.  This checking policy should
+                * catch that case with very few checks and thus save a
+                * lot of checks that are most likely not needed.
+                *
+                * Mods to the above
+                * If an erase check fails or the write fails we skip the 
+                * rest of the block.
+                */
+
+               /* let's give it a try */
+               attempts++;
+
+               if (dev->param.always_check_erased)
+                       bi->skip_erased_check = 0;
+
+               if (!bi->skip_erased_check) {
+                       erased_ok = yaffs_check_chunk_erased(dev, chunk);
+                       if (erased_ok != YAFFS_OK) {
+                               yaffs_trace(YAFFS_TRACE_ERROR,
+                                 "**>> yaffs chunk %d was not erased",
+                                 chunk);
+
+                               /* If not erased, delete this one,
+                                * skip rest of block and
+                                * try another chunk */
+                               yaffs_chunk_del(dev, chunk, 1, __LINE__);
+                               yaffs_skip_rest_of_block(dev);
+                               continue;
+                       }
+               }
+
+               write_ok = yaffs_wr_chunk_tags_nand(dev, chunk, data, tags);
+
+               if (!bi->skip_erased_check)
+                       write_ok =
+                           yaffs_verify_chunk_written(dev, chunk, data, tags);
+
+               if (write_ok != YAFFS_OK) {
+                       /* Clean up aborted write, skip to next block and
+                        * try another chunk */
+                       yaffs_handle_chunk_wr_error(dev, chunk, erased_ok);
+                       continue;
+               }
+
+               bi->skip_erased_check = 1;
+
+               /* Copy the data into the robustification buffer */
+               yaffs_handle_chunk_wr_ok(dev, chunk, data, tags);
+
+       } while (write_ok != YAFFS_OK &&
+                (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
+
+       if (!write_ok)
+               chunk = -1;
+
+       if (attempts > 1) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                       "**>> yaffs write required %d attempts",
+                       attempts);
+               dev->n_retired_writes += (attempts - 1);
+       }
+
+       return chunk;
+}
+
+/*
+ * Block retiring for handling a broken block.
+ */
+
+static void yaffs_retire_block(struct yaffs_dev *dev, int flash_block)
+{
+       struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
+
+       yaffs2_checkpt_invalidate(dev);
+
+       yaffs2_clear_oldest_dirty_seq(dev, bi);
+
+       if (yaffs_mark_bad(dev, flash_block) != YAFFS_OK) {
+               if (yaffs_erase_block(dev, flash_block) != YAFFS_OK) {
+                       yaffs_trace(YAFFS_TRACE_ALWAYS,
+                               "yaffs: Failed to mark bad and erase block %d",
+                               flash_block);
+               } else {
+                       struct yaffs_ext_tags tags;
+                       int chunk_id =
+                           flash_block * dev->param.chunks_per_block;
+
+                       u8 *buffer = yaffs_get_temp_buffer(dev, __LINE__);
+
+                       memset(buffer, 0xff, dev->data_bytes_per_chunk);
+                       yaffs_init_tags(&tags);
+                       tags.seq_number = YAFFS_SEQUENCE_BAD_BLOCK;
+                       if (dev->param.write_chunk_tags_fn(dev, chunk_id -
+                                                          dev->chunk_offset,
+                                                          buffer,
+                                                          &tags) != YAFFS_OK)
+                               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                                       "yaffs: Failed to write bad block marker to block %d",
+                                       flash_block);
+
+                       yaffs_release_temp_buffer(dev, buffer, __LINE__);
+               }
+       }
+
+       bi->block_state = YAFFS_BLOCK_STATE_DEAD;
+       bi->gc_prioritise = 0;
+       bi->needs_retiring = 0;
+
+       dev->n_retired_blocks++;
+}
+
+/*---------------- Name handling functions ------------*/
+
+static u16 yaffs_calc_name_sum(const YCHAR * name)
+{
+       u16 sum = 0;
+       u16 i = 1;
+
+       const YUCHAR *bname = (const YUCHAR *)name;
+       if (bname) {
+               while ((*bname) && (i < (YAFFS_MAX_NAME_LENGTH / 2))) {
+
+                       /* 0x1f mask is case insensitive */
+                       sum += ((*bname) & 0x1f) * i;
+                       i++;
+                       bname++;
+               }
+       }
+       return sum;
+}
+
+void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR * name)
+{
+#ifndef CONFIG_YAFFS_NO_SHORT_NAMES
+       memset(obj->short_name, 0, sizeof(obj->short_name));
+       if (name && 
+               strnlen(name, YAFFS_SHORT_NAME_LENGTH + 1) <=
+           YAFFS_SHORT_NAME_LENGTH)
+               strcpy(obj->short_name, name);
+       else
+               obj->short_name[0] = _Y('\0');
+#endif
+       obj->sum = yaffs_calc_name_sum(name);
+}
+
+void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
+                               const struct yaffs_obj_hdr *oh)
+{
+#ifdef CONFIG_YAFFS_AUTO_UNICODE
+       YCHAR tmp_name[YAFFS_MAX_NAME_LENGTH + 1];
+       memset(tmp_name, 0, sizeof(tmp_name));
+       yaffs_load_name_from_oh(obj->my_dev, tmp_name, oh->name,
+                               YAFFS_MAX_NAME_LENGTH + 1);
+       yaffs_set_obj_name(obj, tmp_name);
+#else
+       yaffs_set_obj_name(obj, oh->name);
+#endif
+}
+
+/*-------------------- TNODES -------------------
+
+ * List of spare tnodes
+ * The list is hooked together using the first pointer
+ * in the tnode.
+ */
+
+struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev)
+{
+       struct yaffs_tnode *tn = yaffs_alloc_raw_tnode(dev);
+       if (tn) {
+               memset(tn, 0, dev->tnode_size);
+               dev->n_tnodes++;
+       }
+
+       dev->checkpoint_blocks_required = 0;    /* force recalculation */
+
+       return tn;
+}
+
+/* FreeTnode frees up a tnode and puts it back on the free list */
+static void yaffs_free_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
+{
+       yaffs_free_raw_tnode(dev, tn);
+       dev->n_tnodes--;
+       dev->checkpoint_blocks_required = 0;    /* force recalculation */
+}
+
+static void yaffs_deinit_tnodes_and_objs(struct yaffs_dev *dev)
+{
+       yaffs_deinit_raw_tnodes_and_objs(dev);
+       dev->n_obj = 0;
+       dev->n_tnodes = 0;
+}
+
+void yaffs_load_tnode_0(struct yaffs_dev *dev, struct yaffs_tnode *tn,
+                       unsigned pos, unsigned val)
+{
+       u32 *map = (u32 *) tn;
+       u32 bit_in_map;
+       u32 bit_in_word;
+       u32 word_in_map;
+       u32 mask;
+
+       pos &= YAFFS_TNODES_LEVEL0_MASK;
+       val >>= dev->chunk_grp_bits;
+
+       bit_in_map = pos * dev->tnode_width;
+       word_in_map = bit_in_map / 32;
+       bit_in_word = bit_in_map & (32 - 1);
+
+       mask = dev->tnode_mask << bit_in_word;
+
+       map[word_in_map] &= ~mask;
+       map[word_in_map] |= (mask & (val << bit_in_word));
+
+       if (dev->tnode_width > (32 - bit_in_word)) {
+               bit_in_word = (32 - bit_in_word);
+               word_in_map++;;
+               mask =
+                   dev->tnode_mask >> ( /*dev->tnode_width - */ bit_in_word);
+               map[word_in_map] &= ~mask;
+               map[word_in_map] |= (mask & (val >> bit_in_word));
+       }
+}
+
+u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
+                        unsigned pos)
+{
+       u32 *map = (u32 *) tn;
+       u32 bit_in_map;
+       u32 bit_in_word;
+       u32 word_in_map;
+       u32 val;
+
+       pos &= YAFFS_TNODES_LEVEL0_MASK;
+
+       bit_in_map = pos * dev->tnode_width;
+       word_in_map = bit_in_map / 32;
+       bit_in_word = bit_in_map & (32 - 1);
+
+       val = map[word_in_map] >> bit_in_word;
+
+       if (dev->tnode_width > (32 - bit_in_word)) {
+               bit_in_word = (32 - bit_in_word);
+               word_in_map++;;
+               val |= (map[word_in_map] << bit_in_word);
+       }
+
+       val &= dev->tnode_mask;
+       val <<= dev->chunk_grp_bits;
+
+       return val;
+}
+
+/* ------------------- End of individual tnode manipulation -----------------*/
+
+/* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
+ * The look up tree is represented by the top tnode and the number of top_level
+ * in the tree. 0 means only the level 0 tnode is in the tree.
+ */
+
+/* FindLevel0Tnode finds the level 0 tnode, if one exists. */
+struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
+                                      struct yaffs_file_var *file_struct,
+                                      u32 chunk_id)
+{
+       struct yaffs_tnode *tn = file_struct->top;
+       u32 i;
+       int required_depth;
+       int level = file_struct->top_level;
+
+       dev = dev;
+
+       /* Check sane level and chunk Id */
+       if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
+               return NULL;
+
+       if (chunk_id > YAFFS_MAX_CHUNK_ID)
+               return NULL;
+
+       /* First check we're tall enough (ie enough top_level) */
+
+       i = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
+       required_depth = 0;
+       while (i) {
+               i >>= YAFFS_TNODES_INTERNAL_BITS;
+               required_depth++;
+       }
+
+       if (required_depth > file_struct->top_level)
+               return NULL;    /* Not tall enough, so we can't find it */
+
+       /* Traverse down to level 0 */
+       while (level > 0 && tn) {
+               tn = tn->internal[(chunk_id >>
+                                  (YAFFS_TNODES_LEVEL0_BITS +
+                                   (level - 1) *
+                                   YAFFS_TNODES_INTERNAL_BITS)) &
+                                 YAFFS_TNODES_INTERNAL_MASK];
+               level--;
+       }
+
+       return tn;
+}
+
+/* AddOrFindLevel0Tnode finds the level 0 tnode if it exists, otherwise first expands the tree.
+ * This happens in two steps:
+ *  1. If the tree isn't tall enough, then make it taller.
+ *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
+ *
+ * Used when modifying the tree.
+ *
+ *  If the tn argument is NULL, then a fresh tnode will be added otherwise the specified tn will
+ *  be plugged into the ttree.
+ */
+
+struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
+                                          struct yaffs_file_var *file_struct,
+                                          u32 chunk_id,
+                                          struct yaffs_tnode *passed_tn)
+{
+       int required_depth;
+       int i;
+       int l;
+       struct yaffs_tnode *tn;
+
+       u32 x;
+
+       /* Check sane level and page Id */
+       if (file_struct->top_level < 0
+           || file_struct->top_level > YAFFS_TNODES_MAX_LEVEL)
+               return NULL;
+
+       if (chunk_id > YAFFS_MAX_CHUNK_ID)
+               return NULL;
+
+       /* First check we're tall enough (ie enough top_level) */
+
+       x = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
+       required_depth = 0;
+       while (x) {
+               x >>= YAFFS_TNODES_INTERNAL_BITS;
+               required_depth++;
+       }
+
+       if (required_depth > file_struct->top_level) {
+               /* Not tall enough, gotta make the tree taller */
+               for (i = file_struct->top_level; i < required_depth; i++) {
+
+                       tn = yaffs_get_tnode(dev);
+
+                       if (tn) {
+                               tn->internal[0] = file_struct->top;
+                               file_struct->top = tn;
+                               file_struct->top_level++;
+                       } else {
+                               yaffs_trace(YAFFS_TRACE_ERROR, "yaffs: no more tnodes");
+                               return NULL;
+                       }
+               }
+       }
+
+       /* Traverse down to level 0, adding anything we need */
+
+       l = file_struct->top_level;
+       tn = file_struct->top;
+
+       if (l > 0) {
+               while (l > 0 && tn) {
+                       x = (chunk_id >>
+                            (YAFFS_TNODES_LEVEL0_BITS +
+                             (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
+                           YAFFS_TNODES_INTERNAL_MASK;
+
+                       if ((l > 1) && !tn->internal[x]) {
+                               /* Add missing non-level-zero tnode */
+                               tn->internal[x] = yaffs_get_tnode(dev);
+                               if (!tn->internal[x])
+                                       return NULL;
+                       } else if (l == 1) {
+                               /* Looking from level 1 at level 0 */
+                               if (passed_tn) {
+                                       /* If we already have one, then release it. */
+                                       if (tn->internal[x])
+                                               yaffs_free_tnode(dev,
+                                                                tn->
+                                                                internal[x]);
+                                       tn->internal[x] = passed_tn;
+
+                               } else if (!tn->internal[x]) {
+                                       /* Don't have one, none passed in */
+                                       tn->internal[x] = yaffs_get_tnode(dev);
+                                       if (!tn->internal[x])
+                                               return NULL;
+                               }
+                       }
+
+                       tn = tn->internal[x];
+                       l--;
+               }
+       } else {
+               /* top is level 0 */
+               if (passed_tn) {
+                       memcpy(tn, passed_tn,
+                              (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8);
+                       yaffs_free_tnode(dev, passed_tn);
+               }
+       }
+
+       return tn;
+}
+
+static int yaffs_tags_match(const struct yaffs_ext_tags *tags, int obj_id,
+                           int chunk_obj)
+{
+       return (tags->chunk_id == chunk_obj &&
+               tags->obj_id == obj_id && !tags->is_deleted) ? 1 : 0;
+
+}
+
+static int yaffs_find_chunk_in_group(struct yaffs_dev *dev, int the_chunk,
+                                    struct yaffs_ext_tags *tags, int obj_id,
+                                    int inode_chunk)
+{
+       int j;
+
+       for (j = 0; the_chunk && j < dev->chunk_grp_size; j++) {
+               if (yaffs_check_chunk_bit
+                   (dev, the_chunk / dev->param.chunks_per_block,
+                    the_chunk % dev->param.chunks_per_block)) {
+
+                       if (dev->chunk_grp_size == 1)
+                               return the_chunk;
+                       else {
+                               yaffs_rd_chunk_tags_nand(dev, the_chunk, NULL,
+                                                        tags);
+                               if (yaffs_tags_match(tags, obj_id, inode_chunk)) {
+                                       /* found it; */
+                                       return the_chunk;
+                               }
+                       }
+               }
+               the_chunk++;
+       }
+       return -1;
+}
+
+static int yaffs_find_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
+                                   struct yaffs_ext_tags *tags)
+{
+       /*Get the Tnode, then get the level 0 offset chunk offset */
+       struct yaffs_tnode *tn;
+       int the_chunk = -1;
+       struct yaffs_ext_tags local_tags;
+       int ret_val = -1;
+
+       struct yaffs_dev *dev = in->my_dev;
+
+       if (!tags) {
+               /* Passed a NULL, so use our own tags space */
+               tags = &local_tags;
+       }
+
+       tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
+
+       if (tn) {
+               the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
+
+               ret_val =
+                   yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
+                                             inode_chunk);
+       }
+       return ret_val;
+}
+
+static int yaffs_find_del_file_chunk(struct yaffs_obj *in, int inode_chunk,
+                                    struct yaffs_ext_tags *tags)
+{
+       /* Get the Tnode, then get the level 0 offset chunk offset */
+       struct yaffs_tnode *tn;
+       int the_chunk = -1;
+       struct yaffs_ext_tags local_tags;
+
+       struct yaffs_dev *dev = in->my_dev;
+       int ret_val = -1;
+
+       if (!tags) {
+               /* Passed a NULL, so use our own tags space */
+               tags = &local_tags;
+       }
+
+       tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
+
+       if (tn) {
+
+               the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
+
+               ret_val =
+                   yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
+                                             inode_chunk);
+
+               /* Delete the entry in the filestructure (if found) */
+               if (ret_val != -1)
+                       yaffs_load_tnode_0(dev, tn, inode_chunk, 0);
+       }
+
+       return ret_val;
+}
+
+int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
+                           int nand_chunk, int in_scan)
+{
+       /* NB in_scan is zero unless scanning.
+        * For forward scanning, in_scan is > 0;
+        * for backward scanning in_scan is < 0
+        *
+        * nand_chunk = 0 is a dummy insert to make sure the tnodes are there.
+        */
+
+       struct yaffs_tnode *tn;
+       struct yaffs_dev *dev = in->my_dev;
+       int existing_cunk;
+       struct yaffs_ext_tags existing_tags;
+       struct yaffs_ext_tags new_tags;
+       unsigned existing_serial, new_serial;
+
+       if (in->variant_type != YAFFS_OBJECT_TYPE_FILE) {
+               /* Just ignore an attempt at putting a chunk into a non-file during scanning
+                * If it is not during Scanning then something went wrong!
+                */
+               if (!in_scan) {
+                       yaffs_trace(YAFFS_TRACE_ERROR,
+                               "yaffs tragedy:attempt to put data chunk into a non-file"
+                               );
+                       YBUG();
+               }
+
+               yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
+               return YAFFS_OK;
+       }
+
+       tn = yaffs_add_find_tnode_0(dev,
+                                   &in->variant.file_variant,
+                                   inode_chunk, NULL);
+       if (!tn)
+               return YAFFS_FAIL;
+
+       if (!nand_chunk)
+               /* Dummy insert, bail now */
+               return YAFFS_OK;
+
+       existing_cunk = yaffs_get_group_base(dev, tn, inode_chunk);
+
+       if (in_scan != 0) {
+               /* If we're scanning then we need to test for duplicates
+                * NB This does not need to be efficient since it should only ever
+                * happen when the power fails during a write, then only one
+                * chunk should ever be affected.
+                *
+                * Correction for YAFFS2: This could happen quite a lot and we need to think about efficiency! TODO
+                * Update: For backward scanning we don't need to re-read tags so this is quite cheap.
+                */
+
+               if (existing_cunk > 0) {
+                       /* NB Right now existing chunk will not be real chunk_id if the chunk group size > 1
+                        *    thus we have to do a FindChunkInFile to get the real chunk id.
+                        *
+                        * We have a duplicate now we need to decide which one to use:
+                        *
+                        * Backwards scanning YAFFS2: The old one is what we use, dump the new one.
+                        * Forward scanning YAFFS2: The new one is what we use, dump the old one.
+                        * YAFFS1: Get both sets of tags and compare serial numbers.
+                        */
+
+                       if (in_scan > 0) {
+                               /* Only do this for forward scanning */
+                               yaffs_rd_chunk_tags_nand(dev,
+                                                        nand_chunk,
+                                                        NULL, &new_tags);
+
+                               /* Do a proper find */
+                               existing_cunk =
+                                   yaffs_find_chunk_in_file(in, inode_chunk,
+                                                            &existing_tags);
+                       }
+
+                       if (existing_cunk <= 0) {
+                               /*Hoosterman - how did this happen? */
+
+                               yaffs_trace(YAFFS_TRACE_ERROR,
+                                       "yaffs tragedy: existing chunk < 0 in scan"
+                                       );
+
+                       }
+
+                       /* NB The deleted flags should be false, otherwise the chunks will
+                        * not be loaded during a scan
+                        */
+
+                       if (in_scan > 0) {
+                               new_serial = new_tags.serial_number;
+                               existing_serial = existing_tags.serial_number;
+                       }
+
+                       if ((in_scan > 0) &&
+                           (existing_cunk <= 0 ||
+                            ((existing_serial + 1) & 3) == new_serial)) {
+                               /* Forward scanning.
+                                * Use new
+                                * Delete the old one and drop through to update the tnode
+                                */
+                               yaffs_chunk_del(dev, existing_cunk, 1,
+                                               __LINE__);
+                       } else {
+                               /* Backward scanning or we want to use the existing one
+                                * Use existing.
+                                * Delete the new one and return early so that the tnode isn't changed
+                                */
+                               yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
+                               return YAFFS_OK;
+                       }
+               }
+
+       }
+
+       if (existing_cunk == 0)
+               in->n_data_chunks++;
+
+       yaffs_load_tnode_0(dev, tn, inode_chunk, nand_chunk);
+
+       return YAFFS_OK;
+}
+
+static void yaffs_soft_del_chunk(struct yaffs_dev *dev, int chunk)
+{
+       struct yaffs_block_info *the_block;
+       unsigned block_no;
+
+       yaffs_trace(YAFFS_TRACE_DELETION, "soft delete chunk %d", chunk);
+
+       block_no = chunk / dev->param.chunks_per_block;
+       the_block = yaffs_get_block_info(dev, block_no);
+       if (the_block) {
+               the_block->soft_del_pages++;
+               dev->n_free_chunks++;
+               yaffs2_update_oldest_dirty_seq(dev, block_no, the_block);
+       }
+}
+
+/* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all the chunks in the file.
+ * All soft deleting does is increment the block's softdelete count and pulls the chunk out
+ * of the tnode.
+ * Thus, essentially this is the same as DeleteWorker except that the chunks are soft deleted.
+ */
+
+static int yaffs_soft_del_worker(struct yaffs_obj *in, struct yaffs_tnode *tn,
+                                u32 level, int chunk_offset)
+{
+       int i;
+       int the_chunk;
+       int all_done = 1;
+       struct yaffs_dev *dev = in->my_dev;
+
+       if (tn) {
+               if (level > 0) {
+
+                       for (i = YAFFS_NTNODES_INTERNAL - 1; all_done && i >= 0;
+                            i--) {
+                               if (tn->internal[i]) {
+                                       all_done =
+                                           yaffs_soft_del_worker(in,
+                                                                 tn->internal
+                                                                 [i],
+                                                                 level - 1,
+                                                                 (chunk_offset
+                                                                  <<
+                                                                  YAFFS_TNODES_INTERNAL_BITS)
+                                                                 + i);
+                                       if (all_done) {
+                                               yaffs_free_tnode(dev,
+                                                                tn->internal
+                                                                [i]);
+                                               tn->internal[i] = NULL;
+                                       } else {
+                                               /* Hoosterman... how could this happen? */
+                                       }
+                               }
+                       }
+                       return (all_done) ? 1 : 0;
+               } else if (level == 0) {
+
+                       for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
+                               the_chunk = yaffs_get_group_base(dev, tn, i);
+                               if (the_chunk) {
+                                       /* Note this does not find the real chunk, only the chunk group.
+                                        * We make an assumption that a chunk group is not larger than
+                                        * a block.
+                                        */
+                                       yaffs_soft_del_chunk(dev, the_chunk);
+                                       yaffs_load_tnode_0(dev, tn, i, 0);
+                               }
+
+                       }
+                       return 1;
+
+               }
+
+       }
+
+       return 1;
+
+}
+
+static void yaffs_remove_obj_from_dir(struct yaffs_obj *obj)
+{
+       struct yaffs_dev *dev = obj->my_dev;
+       struct yaffs_obj *parent;
+
+       yaffs_verify_obj_in_dir(obj);
+       parent = obj->parent;
+
+       yaffs_verify_dir(parent);
+
+       if (dev && dev->param.remove_obj_fn)
+               dev->param.remove_obj_fn(obj);
+
+       list_del_init(&obj->siblings);
+       obj->parent = NULL;
+
+       yaffs_verify_dir(parent);
+}
+
+void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj)
+{
+       if (!directory) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "tragedy: Trying to add an object to a null pointer directory"
+                       );
+               YBUG();
+               return;
+       }
+       if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "tragedy: Trying to add an object to a non-directory"
+                       );
+               YBUG();
+       }
+
+       if (obj->siblings.prev == NULL) {
+               /* Not initialised */
+               YBUG();
+       }
+
+       yaffs_verify_dir(directory);
+
+       yaffs_remove_obj_from_dir(obj);
+
+       /* Now add it */
+       list_add(&obj->siblings, &directory->variant.dir_variant.children);
+       obj->parent = directory;
+
+       if (directory == obj->my_dev->unlinked_dir
+           || directory == obj->my_dev->del_dir) {
+               obj->unlinked = 1;
+               obj->my_dev->n_unlinked_files++;
+               obj->rename_allowed = 0;
+       }
+
+       yaffs_verify_dir(directory);
+       yaffs_verify_obj_in_dir(obj);
+}
+
+static int yaffs_change_obj_name(struct yaffs_obj *obj,
+                                struct yaffs_obj *new_dir,
+                                const YCHAR * new_name, int force, int shadows)
+{
+       int unlink_op;
+       int del_op;
+
+       struct yaffs_obj *existing_target;
+
+       if (new_dir == NULL)
+               new_dir = obj->parent;  /* use the old directory */
+
+       if (new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "tragedy: yaffs_change_obj_name: new_dir is not a directory"
+                       );
+               YBUG();
+       }
+
+       /* TODO: Do we need this different handling for YAFFS2 and YAFFS1?? */
+       if (obj->my_dev->param.is_yaffs2)
+               unlink_op = (new_dir == obj->my_dev->unlinked_dir);
+       else
+               unlink_op = (new_dir == obj->my_dev->unlinked_dir
+                            && obj->variant_type == YAFFS_OBJECT_TYPE_FILE);
+
+       del_op = (new_dir == obj->my_dev->del_dir);
+
+       existing_target = yaffs_find_by_name(new_dir, new_name);
+
+       /* If the object is a file going into the unlinked directory,
+        *   then it is OK to just stuff it in since duplicate names are allowed.
+        *   else only proceed if the new name does not exist and if we're putting
+        *   it into a directory.
+        */
+       if ((unlink_op ||
+            del_op ||
+            force ||
+            (shadows > 0) ||
+            !existing_target) &&
+           new_dir->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY) {
+               yaffs_set_obj_name(obj, new_name);
+               obj->dirty = 1;
+
+               yaffs_add_obj_to_dir(new_dir, obj);
+
+               if (unlink_op)
+                       obj->unlinked = 1;
+
+               /* If it is a deletion then we mark it as a shrink for gc purposes. */
+               if (yaffs_update_oh(obj, new_name, 0, del_op, shadows, NULL) >=
+                   0)
+                       return YAFFS_OK;
+       }
+
+       return YAFFS_FAIL;
+}
+
+/*------------------------ Short Operations Cache ----------------------------------------
+ *   In many situations where there is no high level buffering  a lot of
+ *   reads might be short sequential reads, and a lot of writes may be short
+ *   sequential writes. eg. scanning/writing a jpeg file.
+ *   In these cases, a short read/write cache can provide a huge perfomance
+ *   benefit with dumb-as-a-rock code.
+ *   In Linux, the page cache provides read buffering and the short op cache 
+ *   provides write buffering.
+ *
+ *   There are a limited number (~10) of cache chunks per device so that we don't
+ *   need a very intelligent search.
+ */
+
+static int yaffs_obj_cache_dirty(struct yaffs_obj *obj)
+{
+       struct yaffs_dev *dev = obj->my_dev;
+       int i;
+       struct yaffs_cache *cache;
+       int n_caches = obj->my_dev->param.n_caches;
+
+       for (i = 0; i < n_caches; i++) {
+               cache = &dev->cache[i];
+               if (cache->object == obj && cache->dirty)
+                       return 1;
+       }
+
+       return 0;
+}
+
+static void yaffs_flush_file_cache(struct yaffs_obj *obj)
+{
+       struct yaffs_dev *dev = obj->my_dev;
+       int lowest = -99;       /* Stop compiler whining. */
+       int i;
+       struct yaffs_cache *cache;
+       int chunk_written = 0;
+       int n_caches = obj->my_dev->param.n_caches;
+
+       if (n_caches > 0) {
+               do {
+                       cache = NULL;
+
+                       /* Find the dirty cache for this object with the lowest chunk id. */
+                       for (i = 0; i < n_caches; i++) {
+                               if (dev->cache[i].object == obj &&
+                                   dev->cache[i].dirty) {
+                                       if (!cache
+                                           || dev->cache[i].chunk_id <
+                                           lowest) {
+                                               cache = &dev->cache[i];
+                                               lowest = cache->chunk_id;
+                                       }
+                               }
+                       }
+
+                       if (cache && !cache->locked) {
+                               /* Write it out and free it up */
+
+                               chunk_written =
+                                   yaffs_wr_data_obj(cache->object,
+                                                     cache->chunk_id,
+                                                     cache->data,
+                                                     cache->n_bytes, 1);
+                               cache->dirty = 0;
+                               cache->object = NULL;
+                       }
+
+               } while (cache && chunk_written > 0);
+
+               if (cache)
+                       /* Hoosterman, disk full while writing cache out. */
+                       yaffs_trace(YAFFS_TRACE_ERROR,
+                               "yaffs tragedy: no space during cache write");
+
+       }
+
+}
+
+/*yaffs_flush_whole_cache(dev)
+ *
+ *
+ */
+
+void yaffs_flush_whole_cache(struct yaffs_dev *dev)
+{
+       struct yaffs_obj *obj;
+       int n_caches = dev->param.n_caches;
+       int i;
+
+       /* Find a dirty object in the cache and flush it...
+        * until there are no further dirty objects.
+        */
+       do {
+               obj = NULL;
+               for (i = 0; i < n_caches && !obj; i++) {
+                       if (dev->cache[i].object && dev->cache[i].dirty)
+                               obj = dev->cache[i].object;
+
+               }
+               if (obj)
+                       yaffs_flush_file_cache(obj);
+
+       } while (obj);
+
+}
+
+/* Grab us a cache chunk for use.
+ * First look for an empty one.
+ * Then look for the least recently used non-dirty one.
+ * Then look for the least recently used dirty one...., flush and look again.
+ */
+static struct yaffs_cache *yaffs_grab_chunk_worker(struct yaffs_dev *dev)
+{
+       int i;
+
+       if (dev->param.n_caches > 0) {
+               for (i = 0; i < dev->param.n_caches; i++) {
+                       if (!dev->cache[i].object)
+                               return &dev->cache[i];
+               }
+       }
+
+       return NULL;
+}
+
+static struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev)
+{
+       struct yaffs_cache *cache;
+       struct yaffs_obj *the_obj;
+       int usage;
+       int i;
+       int pushout;
+
+       if (dev->param.n_caches > 0) {
+               /* Try find a non-dirty one... */
+
+               cache = yaffs_grab_chunk_worker(dev);
+
+               if (!cache) {
+                       /* They were all dirty, find the last recently used object and flush
+                        * its cache, then  find again.
+                        * NB what's here is not very accurate, we actually flush the object
+                        * the last recently used page.
+                        */
+
+                       /* With locking we can't assume we can use entry zero */
+
+                       the_obj = NULL;
+                       usage = -1;
+                       cache = NULL;
+                       pushout = -1;
+
+                       for (i = 0; i < dev->param.n_caches; i++) {
+                               if (dev->cache[i].object &&
+                                   !dev->cache[i].locked &&
+                                   (dev->cache[i].last_use < usage
+                                    || !cache)) {
+                                       usage = dev->cache[i].last_use;
+                                       the_obj = dev->cache[i].object;
+                                       cache = &dev->cache[i];
+                                       pushout = i;
+                               }
+                       }
+
+                       if (!cache || cache->dirty) {
+                               /* Flush and try again */
+                               yaffs_flush_file_cache(the_obj);
+                               cache = yaffs_grab_chunk_worker(dev);
+                       }
+
+               }
+               return cache;
+       } else {
+               return NULL;
+        }
+}
+
+/* Find a cached chunk */
+static struct yaffs_cache *yaffs_find_chunk_cache(const struct yaffs_obj *obj,
+                                                 int chunk_id)
+{
+       struct yaffs_dev *dev = obj->my_dev;
+       int i;
+       if (dev->param.n_caches > 0) {
+               for (i = 0; i < dev->param.n_caches; i++) {
+                       if (dev->cache[i].object == obj &&
+                           dev->cache[i].chunk_id == chunk_id) {
+                               dev->cache_hits++;
+
+                               return &dev->cache[i];
+                       }
+               }
+       }
+       return NULL;
+}
+
+/* Mark the chunk for the least recently used algorithym */
+static void yaffs_use_cache(struct yaffs_dev *dev, struct yaffs_cache *cache,
+                           int is_write)
+{
+
+       if (dev->param.n_caches > 0) {
+               if (dev->cache_last_use < 0 || dev->cache_last_use > 100000000) {
+                       /* Reset the cache usages */
+                       int i;
+                       for (i = 1; i < dev->param.n_caches; i++)
+                               dev->cache[i].last_use = 0;
+
+                       dev->cache_last_use = 0;
+               }
+
+               dev->cache_last_use++;
+
+               cache->last_use = dev->cache_last_use;
+
+               if (is_write)
+                       cache->dirty = 1;
+       }
+}
+
+/* Invalidate a single cache page.
+ * Do this when a whole page gets written,
+ * ie the short cache for this page is no longer valid.
+ */
+static void yaffs_invalidate_chunk_cache(struct yaffs_obj *object, int chunk_id)
+{
+       if (object->my_dev->param.n_caches > 0) {
+               struct yaffs_cache *cache =
+                   yaffs_find_chunk_cache(object, chunk_id);
+
+               if (cache)
+                       cache->object = NULL;
+       }
+}
+
+/* Invalidate all the cache pages associated with this object
+ * Do this whenever ther file is deleted or resized.
+ */
+static void yaffs_invalidate_whole_cache(struct yaffs_obj *in)
+{
+       int i;
+       struct yaffs_dev *dev = in->my_dev;
+
+       if (dev->param.n_caches > 0) {
+               /* Invalidate it. */
+               for (i = 0; i < dev->param.n_caches; i++) {
+                       if (dev->cache[i].object == in)
+                               dev->cache[i].object = NULL;
+               }
+       }
+}
+
+static void yaffs_unhash_obj(struct yaffs_obj *obj)
+{
+       int bucket;
+       struct yaffs_dev *dev = obj->my_dev;
+
+       /* If it is still linked into the bucket list, free from the list */
+       if (!list_empty(&obj->hash_link)) {
+               list_del_init(&obj->hash_link);
+               bucket = yaffs_hash_fn(obj->obj_id);
+               dev->obj_bucket[bucket].count--;
+       }
+}
+
+/*  FreeObject frees up a Object and puts it back on the free list */
+static void yaffs_free_obj(struct yaffs_obj *obj)
+{
+       struct yaffs_dev *dev = obj->my_dev;
+
+       yaffs_trace(YAFFS_TRACE_OS, "FreeObject %p inode %p",
+               obj, obj->my_inode);
+
+       if (!obj)
+               YBUG();
+       if (obj->parent)
+               YBUG();
+       if (!list_empty(&obj->siblings))
+               YBUG();
+
+       if (obj->my_inode) {
+               /* We're still hooked up to a cached inode.
+                * Don't delete now, but mark for later deletion
+                */
+               obj->defered_free = 1;
+               return;
+       }
+
+       yaffs_unhash_obj(obj);
+
+       yaffs_free_raw_obj(dev, obj);
+       dev->n_obj--;
+       dev->checkpoint_blocks_required = 0;    /* force recalculation */
+}
+
+void yaffs_handle_defered_free(struct yaffs_obj *obj)
+{
+       if (obj->defered_free)
+               yaffs_free_obj(obj);
+}
+
+static int yaffs_generic_obj_del(struct yaffs_obj *in)
+{
+
+       /* First off, invalidate the file's data in the cache, without flushing. */
+       yaffs_invalidate_whole_cache(in);
+
+       if (in->my_dev->param.is_yaffs2 && (in->parent != in->my_dev->del_dir)) {
+               /* Move to the unlinked directory so we have a record that it was deleted. */
+               yaffs_change_obj_name(in, in->my_dev->del_dir, _Y("deleted"), 0,
+                                     0);
+
+       }
+
+       yaffs_remove_obj_from_dir(in);
+       yaffs_chunk_del(in->my_dev, in->hdr_chunk, 1, __LINE__);
+       in->hdr_chunk = 0;
+
+       yaffs_free_obj(in);
+       return YAFFS_OK;
+
+}
+
+static void yaffs_soft_del_file(struct yaffs_obj *obj)
+{
+       if (obj->deleted &&
+           obj->variant_type == YAFFS_OBJECT_TYPE_FILE && !obj->soft_del) {
+               if (obj->n_data_chunks <= 0) {
+                       /* Empty file with no duplicate object headers,
+                        * just delete it immediately */
+                       yaffs_free_tnode(obj->my_dev,
+                                        obj->variant.file_variant.top);
+                       obj->variant.file_variant.top = NULL;
+                       yaffs_trace(YAFFS_TRACE_TRACING,
+                               "yaffs: Deleting empty file %d",
+                               obj->obj_id);
+                       yaffs_generic_obj_del(obj);
+               } else {
+                       yaffs_soft_del_worker(obj,
+                                             obj->variant.file_variant.top,
+                                             obj->variant.
+                                             file_variant.top_level, 0);
+                       obj->soft_del = 1;
+               }
+       }
+}
+
+/* Pruning removes any part of the file structure tree that is beyond the
+ * bounds of the file (ie that does not point to chunks).
+ *
+ * A file should only get pruned when its size is reduced.
+ *
+ * Before pruning, the chunks must be pulled from the tree and the
+ * level 0 tnode entries must be zeroed out.
+ * Could also use this for file deletion, but that's probably better handled
+ * by a special case.
+ *
+ * This function is recursive. For levels > 0 the function is called again on
+ * any sub-tree. For level == 0 we just check if the sub-tree has data.
+ * If there is no data in a subtree then it is pruned.
+ */
+
+static struct yaffs_tnode *yaffs_prune_worker(struct yaffs_dev *dev,
+                                             struct yaffs_tnode *tn, u32 level,
+                                             int del0)
+{
+       int i;
+       int has_data;
+
+       if (tn) {
+               has_data = 0;
+
+               if (level > 0) {
+                       for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
+                               if (tn->internal[i]) {
+                                       tn->internal[i] =
+                                           yaffs_prune_worker(dev,
+                                                              tn->internal[i],
+                                                              level - 1,
+                                                              (i ==
+                                                               0) ? del0 : 1);
+                               }
+
+                               if (tn->internal[i])
+                                       has_data++;
+                       }
+               } else {
+                       int tnode_size_u32 = dev->tnode_size / sizeof(u32);
+                       u32 *map = (u32 *) tn;
+
+                       for (i = 0; !has_data && i < tnode_size_u32; i++) {
+                               if (map[i])
+                                       has_data++;
+                       }
+               }
+
+               if (has_data == 0 && del0) {
+                       /* Free and return NULL */
+
+                       yaffs_free_tnode(dev, tn);
+                       tn = NULL;
+               }
+
+       }
+
+       return tn;
+
+}
+
+static int yaffs_prune_tree(struct yaffs_dev *dev,
+                           struct yaffs_file_var *file_struct)
+{
+       int i;
+       int has_data;
+       int done = 0;
+       struct yaffs_tnode *tn;
+
+       if (file_struct->top_level > 0) {
+               file_struct->top =
+                   yaffs_prune_worker(dev, file_struct->top,
+                                      file_struct->top_level, 0);
+
+               /* Now we have a tree with all the non-zero branches NULL but the height
+                * is the same as it was.
+                * Let's see if we can trim internal tnodes to shorten the tree.
+                * We can do this if only the 0th element in the tnode is in use
+                * (ie all the non-zero are NULL)
+                */
+
+               while (file_struct->top_level && !done) {
+                       tn = file_struct->top;
+
+                       has_data = 0;
+                       for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
+                               if (tn->internal[i])
+                                       has_data++;
+                       }
+
+                       if (!has_data) {
+                               file_struct->top = tn->internal[0];
+                               file_struct->top_level--;
+                               yaffs_free_tnode(dev, tn);
+                       } else {
+                               done = 1;
+                       }
+               }
+       }
+
+       return YAFFS_OK;
+}
+
+/*-------------------- End of File Structure functions.-------------------*/
+
+/* AllocateEmptyObject gets us a clean Object. Tries to make allocate more if we run out */
+static struct yaffs_obj *yaffs_alloc_empty_obj(struct yaffs_dev *dev)
+{
+       struct yaffs_obj *obj = yaffs_alloc_raw_obj(dev);
+
+       if (obj) {
+               dev->n_obj++;
+
+               /* Now sweeten it up... */
+
+               memset(obj, 0, sizeof(struct yaffs_obj));
+               obj->being_created = 1;
+
+               obj->my_dev = dev;
+               obj->hdr_chunk = 0;
+               obj->variant_type = YAFFS_OBJECT_TYPE_UNKNOWN;
+               INIT_LIST_HEAD(&(obj->hard_links));
+               INIT_LIST_HEAD(&(obj->hash_link));
+               INIT_LIST_HEAD(&obj->siblings);
+
+               /* Now make the directory sane */
+               if (dev->root_dir) {
+                       obj->parent = dev->root_dir;
+                       list_add(&(obj->siblings),
+                                &dev->root_dir->variant.dir_variant.children);
+               }
+
+               /* Add it to the lost and found directory.
+                * NB Can't put root or lost-n-found in lost-n-found so
+                * check if lost-n-found exists first
+                */
+               if (dev->lost_n_found)
+                       yaffs_add_obj_to_dir(dev->lost_n_found, obj);
+
+               obj->being_created = 0;
+       }
+
+       dev->checkpoint_blocks_required = 0;    /* force recalculation */
+
+       return obj;
+}
+
+static int yaffs_find_nice_bucket(struct yaffs_dev *dev)
+{
+       int i;
+       int l = 999;
+       int lowest = 999999;
+
+       /* Search for the shortest list or one that
+        * isn't too long.
+        */
+
+       for (i = 0; i < 10 && lowest > 4; i++) {
+               dev->bucket_finder++;
+               dev->bucket_finder %= YAFFS_NOBJECT_BUCKETS;
+               if (dev->obj_bucket[dev->bucket_finder].count < lowest) {
+                       lowest = dev->obj_bucket[dev->bucket_finder].count;
+                       l = dev->bucket_finder;
+               }
+
+       }
+
+       return l;
+}
+
+static int yaffs_new_obj_id(struct yaffs_dev *dev)
+{
+       int bucket = yaffs_find_nice_bucket(dev);
+
+       /* Now find an object value that has not already been taken
+        * by scanning the list.
+        */
+
+       int found = 0;
+       struct list_head *i;
+
+       u32 n = (u32) bucket;
+
+       /* yaffs_check_obj_hash_sane();  */
+
+       while (!found) {
+               found = 1;
+               n += YAFFS_NOBJECT_BUCKETS;
+               if (1 || dev->obj_bucket[bucket].count > 0) {
+                       list_for_each(i, &dev->obj_bucket[bucket].list) {
+                               /* If there is already one in the list */
+                               if (i && list_entry(i, struct yaffs_obj,
+                                                   hash_link)->obj_id == n) {
+                                       found = 0;
+                               }
+                       }
+               }
+       }
+
+       return n;
+}
+
+static void yaffs_hash_obj(struct yaffs_obj *in)
+{
+       int bucket = yaffs_hash_fn(in->obj_id);
+       struct yaffs_dev *dev = in->my_dev;
+
+       list_add(&in->hash_link, &dev->obj_bucket[bucket].list);
+       dev->obj_bucket[bucket].count++;
+}
+
+struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number)
+{
+       int bucket = yaffs_hash_fn(number);
+       struct list_head *i;
+       struct yaffs_obj *in;
+
+       list_for_each(i, &dev->obj_bucket[bucket].list) {
+               /* Look if it is in the list */
+               if (i) {
+                       in = list_entry(i, struct yaffs_obj, hash_link);
+                       if (in->obj_id == number) {
+
+                               /* Don't tell the VFS about this one if it is defered free */
+                               if (in->defered_free)
+                                       return NULL;
+
+                               return in;
+                       }
+               }
+       }
+
+       return NULL;
+}
+
+struct yaffs_obj *yaffs_new_obj(struct yaffs_dev *dev, int number,
+                               enum yaffs_obj_type type)
+{
+       struct yaffs_obj *the_obj = NULL;
+       struct yaffs_tnode *tn = NULL;
+
+       if (number < 0)
+               number = yaffs_new_obj_id(dev);
+
+       if (type == YAFFS_OBJECT_TYPE_FILE) {
+               tn = yaffs_get_tnode(dev);
+               if (!tn)
+                       return NULL;
+       }
+
+       the_obj = yaffs_alloc_empty_obj(dev);
+       if (!the_obj) {
+               if (tn)
+                       yaffs_free_tnode(dev, tn);
+               return NULL;
+       }
+
+       if (the_obj) {
+               the_obj->fake = 0;
+               the_obj->rename_allowed = 1;
+               the_obj->unlink_allowed = 1;
+               the_obj->obj_id = number;
+               yaffs_hash_obj(the_obj);
+               the_obj->variant_type = type;
+               yaffs_load_current_time(the_obj, 1, 1);
+
+               switch (type) {
+               case YAFFS_OBJECT_TYPE_FILE:
+                       the_obj->variant.file_variant.file_size = 0;
+                       the_obj->variant.file_variant.scanned_size = 0;
+                       the_obj->variant.file_variant.shrink_size = ~0; /* max */
+                       the_obj->variant.file_variant.top_level = 0;
+                       the_obj->variant.file_variant.top = tn;
+                       break;
+               case YAFFS_OBJECT_TYPE_DIRECTORY:
+                       INIT_LIST_HEAD(&the_obj->variant.dir_variant.children);
+                       INIT_LIST_HEAD(&the_obj->variant.dir_variant.dirty);
+                       break;
+               case YAFFS_OBJECT_TYPE_SYMLINK:
+               case YAFFS_OBJECT_TYPE_HARDLINK:
+               case YAFFS_OBJECT_TYPE_SPECIAL:
+                       /* No action required */
+                       break;
+               case YAFFS_OBJECT_TYPE_UNKNOWN:
+                       /* todo this should not happen */
+                       break;
+               }
+       }
+
+       return the_obj;
+}
+
+static struct yaffs_obj *yaffs_create_fake_dir(struct yaffs_dev *dev,
+                                              int number, u32 mode)
+{
+
+       struct yaffs_obj *obj =
+           yaffs_new_obj(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
+       if (obj) {
+               obj->fake = 1;  /* it is fake so it might have no NAND presence... */
+               obj->rename_allowed = 0;        /* ... and we're not allowed to rename it... */
+               obj->unlink_allowed = 0;        /* ... or unlink it */
+               obj->deleted = 0;
+               obj->unlinked = 0;
+               obj->yst_mode = mode;
+               obj->my_dev = dev;
+               obj->hdr_chunk = 0;     /* Not a valid chunk. */
+       }
+
+       return obj;
+
+}
+
+
+static void yaffs_init_tnodes_and_objs(struct yaffs_dev *dev)
+{
+       int i;
+
+       dev->n_obj = 0;
+       dev->n_tnodes = 0;
+
+       yaffs_init_raw_tnodes_and_objs(dev);
+
+       for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
+               INIT_LIST_HEAD(&dev->obj_bucket[i].list);
+               dev->obj_bucket[i].count = 0;
+       }
+}
+
+struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
+                                                int number,
+                                                enum yaffs_obj_type type)
+{
+       struct yaffs_obj *the_obj = NULL;
+
+       if (number > 0)
+               the_obj = yaffs_find_by_number(dev, number);
+
+       if (!the_obj)
+               the_obj = yaffs_new_obj(dev, number, type);
+
+       return the_obj;
+
+}
+
+YCHAR *yaffs_clone_str(const YCHAR * str)
+{
+       YCHAR *new_str = NULL;
+       int len;
+
+       if (!str)
+               str = _Y("");
+
+       len = strnlen(str, YAFFS_MAX_ALIAS_LENGTH);
+       new_str = kmalloc((len + 1) * sizeof(YCHAR), GFP_NOFS);
+       if (new_str) {
+               strncpy(new_str, str, len);
+               new_str[len] = 0;
+       }
+       return new_str;
+
+}
+/*
+ *yaffs_update_parent() handles fixing a directories mtime and ctime when a new
+ * link (ie. name) is created or deleted in the directory.
+ *
+ * ie.
+ *   create dir/a : update dir's mtime/ctime
+ *   rm dir/a:   update dir's mtime/ctime
+ *   modify dir/a: don't update dir's mtimme/ctime
+ *
+ * This can be handled immediately or defered. Defering helps reduce the number
+ * of updates when many files in a directory are changed within a brief period.
+ *
+ * If the directory updating is defered then yaffs_update_dirty_dirs must be
+ * called periodically.
+ */
+
+static void yaffs_update_parent(struct yaffs_obj *obj)
+{
+       struct yaffs_dev *dev;
+       if (!obj)
+               return;
+       dev = obj->my_dev;
+       obj->dirty = 1;
+       yaffs_load_current_time(obj, 0, 1);
+       if (dev->param.defered_dir_update) {
+               struct list_head *link = &obj->variant.dir_variant.dirty;
+
+               if (list_empty(link)) {
+                       list_add(link, &dev->dirty_dirs);
+                       yaffs_trace(YAFFS_TRACE_BACKGROUND,
+                         "Added object %d to dirty directories",
+                          obj->obj_id);
+               }
+
+       } else {
+               yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
+        }
+}
+
+void yaffs_update_dirty_dirs(struct yaffs_dev *dev)
+{
+       struct list_head *link;
+       struct yaffs_obj *obj;
+       struct yaffs_dir_var *d_s;
+       union yaffs_obj_var *o_v;
+
+       yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update dirty directories");
+
+       while (!list_empty(&dev->dirty_dirs)) {
+               link = dev->dirty_dirs.next;
+               list_del_init(link);
+
+               d_s = list_entry(link, struct yaffs_dir_var, dirty);
+               o_v = list_entry(d_s, union yaffs_obj_var, dir_variant);
+               obj = list_entry(o_v, struct yaffs_obj, variant);
+
+               yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update directory %d",
+                       obj->obj_id);
+
+               if (obj->dirty)
+                       yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
+       }
+}
+
+/*
+ * Mknod (create) a new object.
+ * equiv_obj only has meaning for a hard link;
+ * alias_str only has meaning for a symlink.
+ * rdev only has meaning for devices (a subset of special objects)
+ */
+
+static struct yaffs_obj *yaffs_create_obj(enum yaffs_obj_type type,
+                                         struct yaffs_obj *parent,
+                                         const YCHAR * name,
+                                         u32 mode,
+                                         u32 uid,
+                                         u32 gid,
+                                         struct yaffs_obj *equiv_obj,
+                                         const YCHAR * alias_str, u32 rdev)
+{
+       struct yaffs_obj *in;
+       YCHAR *str = NULL;
+
+       struct yaffs_dev *dev = parent->my_dev;
+
+       /* Check if the entry exists. If it does then fail the call since we don't want a dup. */
+       if (yaffs_find_by_name(parent, name))
+               return NULL;
+
+       if (type == YAFFS_OBJECT_TYPE_SYMLINK) {
+               str = yaffs_clone_str(alias_str);
+               if (!str)
+                       return NULL;
+       }
+
+       in = yaffs_new_obj(dev, -1, type);
+
+       if (!in) {
+               if (str)
+                       kfree(str);
+               return NULL;
+       }
+
+       if (in) {
+               in->hdr_chunk = 0;
+               in->valid = 1;
+               in->variant_type = type;
+
+               in->yst_mode = mode;
+
+               yaffs_attribs_init(in, gid, uid, rdev);
+
+               in->n_data_chunks = 0;
+
+               yaffs_set_obj_name(in, name);
+               in->dirty = 1;
+
+               yaffs_add_obj_to_dir(parent, in);
+
+               in->my_dev = parent->my_dev;
+
+               switch (type) {
+               case YAFFS_OBJECT_TYPE_SYMLINK:
+                       in->variant.symlink_variant.alias = str;
+                       break;
+               case YAFFS_OBJECT_TYPE_HARDLINK:
+                       in->variant.hardlink_variant.equiv_obj = equiv_obj;
+                       in->variant.hardlink_variant.equiv_id =
+                           equiv_obj->obj_id;
+                       list_add(&in->hard_links, &equiv_obj->hard_links);
+                       break;
+               case YAFFS_OBJECT_TYPE_FILE:
+               case YAFFS_OBJECT_TYPE_DIRECTORY:
+               case YAFFS_OBJECT_TYPE_SPECIAL:
+               case YAFFS_OBJECT_TYPE_UNKNOWN:
+                       /* do nothing */
+                       break;
+               }
+
+               if (yaffs_update_oh(in, name, 0, 0, 0, NULL) < 0) {
+                       /* Could not create the object header, fail the creation */
+                       yaffs_del_obj(in);
+                       in = NULL;
+               }
+
+               yaffs_update_parent(parent);
+       }
+
+       return in;
+}
+
+struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
+                                   const YCHAR * name, u32 mode, u32 uid,
+                                   u32 gid)
+{
+       return yaffs_create_obj(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
+                               uid, gid, NULL, NULL, 0);
+}
+
+struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR * name,
+                                  u32 mode, u32 uid, u32 gid)
+{
+       return yaffs_create_obj(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
+                               mode, uid, gid, NULL, NULL, 0);
+}
+
+struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
+                                      const YCHAR * name, u32 mode, u32 uid,
+                                      u32 gid, u32 rdev)
+{
+       return yaffs_create_obj(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
+                               uid, gid, NULL, NULL, rdev);
+}
+
+struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
+                                      const YCHAR * name, u32 mode, u32 uid,
+                                      u32 gid, const YCHAR * alias)
+{
+       return yaffs_create_obj(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
+                               uid, gid, NULL, alias, 0);
+}
+
+/* yaffs_link_obj returns the object id of the equivalent object.*/
+struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR * name,
+                                struct yaffs_obj *equiv_obj)
+{
+       /* Get the real object in case we were fed a hard link as an equivalent object */
+       equiv_obj = yaffs_get_equivalent_obj(equiv_obj);
+
+       if (yaffs_create_obj
+           (YAFFS_OBJECT_TYPE_HARDLINK, parent, name, 0, 0, 0,
+            equiv_obj, NULL, 0)) {
+               return equiv_obj;
+       } else {
+               return NULL;
+       }
+
+}
+
+
+
+/*------------------------- Block Management and Page Allocation ----------------*/
+
+static int yaffs_init_blocks(struct yaffs_dev *dev)
+{
+       int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
+
+       dev->block_info = NULL;
+       dev->chunk_bits = NULL;
+
+       dev->alloc_block = -1;  /* force it to get a new one */
+
+       /* If the first allocation strategy fails, thry the alternate one */
+       dev->block_info =
+               kmalloc(n_blocks * sizeof(struct yaffs_block_info), GFP_NOFS);
+       if (!dev->block_info) {
+               dev->block_info =
+                   vmalloc(n_blocks * sizeof(struct yaffs_block_info));
+               dev->block_info_alt = 1;
+       } else {
+               dev->block_info_alt = 0;
+        }
+
+       if (dev->block_info) {
+               /* Set up dynamic blockinfo stuff. Round up bytes. */
+               dev->chunk_bit_stride = (dev->param.chunks_per_block + 7) / 8;
+               dev->chunk_bits =
+                       kmalloc(dev->chunk_bit_stride * n_blocks, GFP_NOFS);
+               if (!dev->chunk_bits) {
+                       dev->chunk_bits =
+                           vmalloc(dev->chunk_bit_stride * n_blocks);
+                       dev->chunk_bits_alt = 1;
+               } else {
+                       dev->chunk_bits_alt = 0;
+                }
+       }
+
+       if (dev->block_info && dev->chunk_bits) {
+               memset(dev->block_info, 0,
+                      n_blocks * sizeof(struct yaffs_block_info));
+               memset(dev->chunk_bits, 0, dev->chunk_bit_stride * n_blocks);
+               return YAFFS_OK;
+       }
+
+       return YAFFS_FAIL;
+}
+
+static void yaffs_deinit_blocks(struct yaffs_dev *dev)
+{
+       if (dev->block_info_alt && dev->block_info)
+               vfree(dev->block_info);
+       else if (dev->block_info)
+               kfree(dev->block_info);
+
+       dev->block_info_alt = 0;
+
+       dev->block_info = NULL;
+
+       if (dev->chunk_bits_alt && dev->chunk_bits)
+               vfree(dev->chunk_bits);
+       else if (dev->chunk_bits)
+               kfree(dev->chunk_bits);
+       dev->chunk_bits_alt = 0;
+       dev->chunk_bits = NULL;
+}
+
+void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no)
+{
+       struct yaffs_block_info *bi = yaffs_get_block_info(dev, block_no);
+
+       int erased_ok = 0;
+
+       /* If the block is still healthy erase it and mark as clean.
+        * If the block has had a data failure, then retire it.
+        */
+
+       yaffs_trace(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
+               "yaffs_block_became_dirty block %d state %d %s",
+               block_no, bi->block_state,
+               (bi->needs_retiring) ? "needs retiring" : "");
+
+       yaffs2_clear_oldest_dirty_seq(dev, bi);
+
+       bi->block_state = YAFFS_BLOCK_STATE_DIRTY;
+
+       /* If this is the block being garbage collected then stop gc'ing this block */
+       if (block_no == dev->gc_block)
+               dev->gc_block = 0;
+
+       /* If this block is currently the best candidate for gc then drop as a candidate */
+       if (block_no == dev->gc_dirtiest) {
+               dev->gc_dirtiest = 0;
+               dev->gc_pages_in_use = 0;
+       }
+
+       if (!bi->needs_retiring) {
+               yaffs2_checkpt_invalidate(dev);
+               erased_ok = yaffs_erase_block(dev, block_no);
+               if (!erased_ok) {
+                       dev->n_erase_failures++;
+                       yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
+                         "**>> Erasure failed %d", block_no);
+               }
+       }
+
+       if (erased_ok &&
+           ((yaffs_trace_mask & YAFFS_TRACE_ERASE)
+            || !yaffs_skip_verification(dev))) {
+               int i;
+               for (i = 0; i < dev->param.chunks_per_block; i++) {
+                       if (!yaffs_check_chunk_erased
+                           (dev, block_no * dev->param.chunks_per_block + i)) {
+                               yaffs_trace(YAFFS_TRACE_ERROR,
+                                       ">>Block %d erasure supposedly OK, but chunk %d not erased",
+                                       block_no, i);
+                       }
+               }
+       }
+
+       if (erased_ok) {
+               /* Clean it up... */
+               bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
+               bi->seq_number = 0;
+               dev->n_erased_blocks++;
+               bi->pages_in_use = 0;
+               bi->soft_del_pages = 0;
+               bi->has_shrink_hdr = 0;
+               bi->skip_erased_check = 1;      /* Clean, so no need to check */
+               bi->gc_prioritise = 0;
+               yaffs_clear_chunk_bits(dev, block_no);
+
+               yaffs_trace(YAFFS_TRACE_ERASE,
+                       "Erased block %d", block_no);
+       } else {
+               /* We lost a block of free space */
+               dev->n_free_chunks -= dev->param.chunks_per_block;
+               yaffs_retire_block(dev, block_no);
+               yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
+                       "**>> Block %d retired", block_no);
+       }
+}
+
+
+
+static int yaffs_gc_block(struct yaffs_dev *dev, int block, int whole_block)
+{
+       int old_chunk;
+       int new_chunk;
+       int mark_flash;
+       int ret_val = YAFFS_OK;
+       int i;
+       int is_checkpt_block;
+       int matching_chunk;
+       int max_copies;
+
+       int chunks_before = yaffs_get_erased_chunks(dev);
+       int chunks_after;
+
+       struct yaffs_ext_tags tags;
+
+       struct yaffs_block_info *bi = yaffs_get_block_info(dev, block);
+
+       struct yaffs_obj *object;
+
+       is_checkpt_block = (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT);
+
+       yaffs_trace(YAFFS_TRACE_TRACING,
+               "Collecting block %d, in use %d, shrink %d, whole_block %d",
+               block, bi->pages_in_use, bi->has_shrink_hdr,
+               whole_block);
+
+       /*yaffs_verify_free_chunks(dev); */
+
+       if (bi->block_state == YAFFS_BLOCK_STATE_FULL)
+               bi->block_state = YAFFS_BLOCK_STATE_COLLECTING;
+
+       bi->has_shrink_hdr = 0; /* clear the flag so that the block can erase */
+
+       dev->gc_disable = 1;
+
+       if (is_checkpt_block || !yaffs_still_some_chunks(dev, block)) {
+               yaffs_trace(YAFFS_TRACE_TRACING,
+                       "Collecting block %d that has no chunks in use",
+                       block);
+               yaffs_block_became_dirty(dev, block);
+       } else {
+
+               u8 *buffer = yaffs_get_temp_buffer(dev, __LINE__);
+
+               yaffs_verify_blk(dev, bi, block);
+
+               max_copies = (whole_block) ? dev->param.chunks_per_block : 5;
+               old_chunk = block * dev->param.chunks_per_block + dev->gc_chunk;
+
+               for ( /* init already done */ ;
+                    ret_val == YAFFS_OK &&
+                    dev->gc_chunk < dev->param.chunks_per_block &&
+                    (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) &&
+                    max_copies > 0; dev->gc_chunk++, old_chunk++) {
+                       if (yaffs_check_chunk_bit(dev, block, dev->gc_chunk)) {
+
+                               /* This page is in use and might need to be copied off */
+
+                               max_copies--;
+
+                               mark_flash = 1;
+
+                               yaffs_init_tags(&tags);
+
+                               yaffs_rd_chunk_tags_nand(dev, old_chunk,
+                                                        buffer, &tags);
+
+                               object = yaffs_find_by_number(dev, tags.obj_id);
+
+                               yaffs_trace(YAFFS_TRACE_GC_DETAIL,
+                                       "Collecting chunk in block %d, %d %d %d ",
+                                       dev->gc_chunk, tags.obj_id,
+                                       tags.chunk_id, tags.n_bytes);
+
+                               if (object && !yaffs_skip_verification(dev)) {
+                                       if (tags.chunk_id == 0)
+                                               matching_chunk =
+                                                   object->hdr_chunk;
+                                       else if (object->soft_del)
+                                               matching_chunk = old_chunk;     /* Defeat the test */
+                                       else
+                                               matching_chunk =
+                                                   yaffs_find_chunk_in_file
+                                                   (object, tags.chunk_id,
+                                                    NULL);
+
+                                       if (old_chunk != matching_chunk)
+                                               yaffs_trace(YAFFS_TRACE_ERROR,
+                                                       "gc: page in gc mismatch: %d %d %d %d",
+                                                       old_chunk,
+                                                       matching_chunk,
+                                                       tags.obj_id,
+                                                       tags.chunk_id);
+
+                               }
+
+                               if (!object) {
+                                       yaffs_trace(YAFFS_TRACE_ERROR,
+                                               "page %d in gc has no object: %d %d %d ",
+                                               old_chunk,
+                                               tags.obj_id, tags.chunk_id,
+                                               tags.n_bytes);
+                               }
+
+                               if (object &&
+                                   object->deleted &&
+                                   object->soft_del && tags.chunk_id != 0) {
+                                       /* Data chunk in a soft deleted file, throw it away
+                                        * It's a soft deleted data chunk,
+                                        * No need to copy this, just forget about it and
+                                        * fix up the object.
+                                        */
+
+                                       /* Free chunks already includes softdeleted chunks.
+                                        * How ever this chunk is going to soon be really deleted
+                                        * which will increment free chunks.
+                                        * We have to decrement free chunks so this works out properly.
+                                        */
+                                       dev->n_free_chunks--;
+                                       bi->soft_del_pages--;
+
+                                       object->n_data_chunks--;
+
+                                       if (object->n_data_chunks <= 0) {
+                                               /* remeber to clean up the object */
+                                               dev->gc_cleanup_list[dev->
+                                                                    n_clean_ups]
+                                                   = tags.obj_id;
+                                               dev->n_clean_ups++;
+                                       }
+                                       mark_flash = 0;
+                               } else if (0) {
+                                       /* Todo object && object->deleted && object->n_data_chunks == 0 */
+                                       /* Deleted object header with no data chunks.
+                                        * Can be discarded and the file deleted.
+                                        */
+                                       object->hdr_chunk = 0;
+                                       yaffs_free_tnode(object->my_dev,
+                                                        object->
+                                                        variant.file_variant.
+                                                        top);
+                                       object->variant.file_variant.top = NULL;
+                                       yaffs_generic_obj_del(object);
+
+                               } else if (object) {
+                                       /* It's either a data chunk in a live file or
+                                        * an ObjectHeader, so we're interested in it.
+                                        * NB Need to keep the ObjectHeaders of deleted files
+                                        * until the whole file has been deleted off
+                                        */
+                                       tags.serial_number++;
+
+                                       dev->n_gc_copies++;
+
+                                       if (tags.chunk_id == 0) {
+                                               /* It is an object Id,
+                                                * We need to nuke the shrinkheader flags first
+                                                * Also need to clean up shadowing.
+                                                * We no longer want the shrink_header flag since its work is done
+                                                * and if it is left in place it will mess up scanning.
+                                                */
+
+                                               struct yaffs_obj_hdr *oh;
+                                               oh = (struct yaffs_obj_hdr *)
+                                                   buffer;
+
+                                               oh->is_shrink = 0;
+                                               tags.extra_is_shrink = 0;
+
+                                               oh->shadows_obj = 0;
+                                               oh->inband_shadowed_obj_id = 0;
+                                               tags.extra_shadows = 0;
+
+                                               /* Update file size */
+                                               if (object->variant_type ==
+                                                   YAFFS_OBJECT_TYPE_FILE) {
+                                                       oh->file_size =
+                                                           object->variant.
+                                                           file_variant.
+                                                           file_size;
+                                                       tags.extra_length =
+                                                           oh->file_size;
+                                               }
+
+                                               yaffs_verify_oh(object, oh,
+                                                               &tags, 1);
+                                               new_chunk =
+                                                   yaffs_write_new_chunk(dev,
+                                                                         (u8 *)
+                                                                         oh,
+                                                                         &tags,
+                                                                         1);
+                                       } else {
+                                               new_chunk =
+                                                   yaffs_write_new_chunk(dev,
+                                                                         buffer,
+                                                                         &tags,
+                                                                         1);
+                                        }
+
+                                       if (new_chunk < 0) {
+                                               ret_val = YAFFS_FAIL;
+                                       } else {
+
+                                               /* Ok, now fix up the Tnodes etc. */
+
+                                               if (tags.chunk_id == 0) {
+                                                       /* It's a header */
+                                                       object->hdr_chunk =
+                                                           new_chunk;
+                                                       object->serial =
+                                                           tags.serial_number;
+                                               } else {
+                                                       /* It's a data chunk */
+                                                       int ok;
+                                                       ok = yaffs_put_chunk_in_file(object, tags.chunk_id, new_chunk, 0);
+                                               }
+                                       }
+                               }
+
+                               if (ret_val == YAFFS_OK)
+                                       yaffs_chunk_del(dev, old_chunk,
+                                                       mark_flash, __LINE__);
+
+                       }
+               }
+
+               yaffs_release_temp_buffer(dev, buffer, __LINE__);
+
+       }
+
+       yaffs_verify_collected_blk(dev, bi, block);
+
+       if (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
+               /*
+                * The gc did not complete. Set block state back to FULL
+                * because checkpointing does not restore gc.
+                */
+               bi->block_state = YAFFS_BLOCK_STATE_FULL;
+       } else {
+               /* The gc completed. */
+               /* Do any required cleanups */
+               for (i = 0; i < dev->n_clean_ups; i++) {
+                       /* Time to delete the file too */
+                       object =
+                           yaffs_find_by_number(dev, dev->gc_cleanup_list[i]);
+                       if (object) {
+                               yaffs_free_tnode(dev,
+                                                object->variant.
+                                                file_variant.top);
+                               object->variant.file_variant.top = NULL;
+                               yaffs_trace(YAFFS_TRACE_GC,
+                                       "yaffs: About to finally delete object %d",
+                                       object->obj_id);
+                               yaffs_generic_obj_del(object);
+                               object->my_dev->n_deleted_files--;
+                       }
+
+               }
+
+               chunks_after = yaffs_get_erased_chunks(dev);
+               if (chunks_before >= chunks_after)
+                       yaffs_trace(YAFFS_TRACE_GC,
+                               "gc did not increase free chunks before %d after %d",
+                               chunks_before, chunks_after);
+               dev->gc_block = 0;
+               dev->gc_chunk = 0;
+               dev->n_clean_ups = 0;
+       }
+
+       dev->gc_disable = 0;
+
+       return ret_val;
+}
+
+/*
+ * FindBlockForgarbageCollection is used to select the dirtiest block (or close enough)
+ * for garbage collection.
+ */
+
+static unsigned yaffs_find_gc_block(struct yaffs_dev *dev,
+                                   int aggressive, int background)
+{
+       int i;
+       int iterations;
+       unsigned selected = 0;
+       int prioritised = 0;
+       int prioritised_exist = 0;
+       struct yaffs_block_info *bi;
+       int threshold;
+
+       /* First let's see if we need to grab a prioritised block */
+       if (dev->has_pending_prioritised_gc && !aggressive) {
+               dev->gc_dirtiest = 0;
+               bi = dev->block_info;
+               for (i = dev->internal_start_block;
+                    i <= dev->internal_end_block && !selected; i++) {
+
+                       if (bi->gc_prioritise) {
+                               prioritised_exist = 1;
+                               if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
+                                   yaffs_block_ok_for_gc(dev, bi)) {
+                                       selected = i;
+                                       prioritised = 1;
+                               }
+                       }
+                       bi++;
+               }
+
+               /*
+                * If there is a prioritised block and none was selected then
+                * this happened because there is at least one old dirty block gumming
+                * up the works. Let's gc the oldest dirty block.
+                */
+
+               if (prioritised_exist &&
+                   !selected && dev->oldest_dirty_block > 0)
+                       selected = dev->oldest_dirty_block;
+
+               if (!prioritised_exist) /* None found, so we can clear this */
+                       dev->has_pending_prioritised_gc = 0;
+       }
+
+       /* If we're doing aggressive GC then we are happy to take a less-dirty block, and
+        * search harder.
+        * else (we're doing a leasurely gc), then we only bother to do this if the
+        * block has only a few pages in use.
+        */
+
+       if (!selected) {
+               int pages_used;
+               int n_blocks =
+                   dev->internal_end_block - dev->internal_start_block + 1;
+               if (aggressive) {
+                       threshold = dev->param.chunks_per_block;
+                       iterations = n_blocks;
+               } else {
+                       int max_threshold;
+
+                       if (background)
+                               max_threshold = dev->param.chunks_per_block / 2;
+                       else
+                               max_threshold = dev->param.chunks_per_block / 8;
+
+                       if (max_threshold < YAFFS_GC_PASSIVE_THRESHOLD)
+                               max_threshold = YAFFS_GC_PASSIVE_THRESHOLD;
+
+                       threshold = background ? (dev->gc_not_done + 2) * 2 : 0;
+                       if (threshold < YAFFS_GC_PASSIVE_THRESHOLD)
+                               threshold = YAFFS_GC_PASSIVE_THRESHOLD;
+                       if (threshold > max_threshold)
+                               threshold = max_threshold;
+
+                       iterations = n_blocks / 16 + 1;
+                       if (iterations > 100)
+                               iterations = 100;
+               }
+
+               for (i = 0;
+                    i < iterations &&
+                    (dev->gc_dirtiest < 1 ||
+                     dev->gc_pages_in_use > YAFFS_GC_GOOD_ENOUGH); i++) {
+                       dev->gc_block_finder++;
+                       if (dev->gc_block_finder < dev->internal_start_block ||
+                           dev->gc_block_finder > dev->internal_end_block)
+                               dev->gc_block_finder =
+                                   dev->internal_start_block;
+
+                       bi = yaffs_get_block_info(dev, dev->gc_block_finder);
+
+                       pages_used = bi->pages_in_use - bi->soft_del_pages;
+
+                       if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
+                           pages_used < dev->param.chunks_per_block &&
+                           (dev->gc_dirtiest < 1
+                            || pages_used < dev->gc_pages_in_use)
+                           && yaffs_block_ok_for_gc(dev, bi)) {
+                               dev->gc_dirtiest = dev->gc_block_finder;
+                               dev->gc_pages_in_use = pages_used;
+                       }
+               }
+
+               if (dev->gc_dirtiest > 0 && dev->gc_pages_in_use <= threshold)
+                       selected = dev->gc_dirtiest;
+       }
+
+       /*
+        * If nothing has been selected for a while, try selecting the oldest dirty
+        * because that's gumming up the works.
+        */
+
+       if (!selected && dev->param.is_yaffs2 &&
+           dev->gc_not_done >= (background ? 10 : 20)) {
+               yaffs2_find_oldest_dirty_seq(dev);
+               if (dev->oldest_dirty_block > 0) {
+                       selected = dev->oldest_dirty_block;
+                       dev->gc_dirtiest = selected;
+                       dev->oldest_dirty_gc_count++;
+                       bi = yaffs_get_block_info(dev, selected);
+                       dev->gc_pages_in_use =
+                           bi->pages_in_use - bi->soft_del_pages;
+               } else {
+                       dev->gc_not_done = 0;
+                }
+       }
+
+       if (selected) {
+               yaffs_trace(YAFFS_TRACE_GC,
+                       "GC Selected block %d with %d free, prioritised:%d",
+                       selected,
+                       dev->param.chunks_per_block - dev->gc_pages_in_use,
+                       prioritised);
+
+               dev->n_gc_blocks++;
+               if (background)
+                       dev->bg_gcs++;
+
+               dev->gc_dirtiest = 0;
+               dev->gc_pages_in_use = 0;
+               dev->gc_not_done = 0;
+               if (dev->refresh_skip > 0)
+                       dev->refresh_skip--;
+       } else {
+               dev->gc_not_done++;
+               yaffs_trace(YAFFS_TRACE_GC,
+                       "GC none: finder %d skip %d threshold %d dirtiest %d using %d oldest %d%s",
+                       dev->gc_block_finder, dev->gc_not_done, threshold,
+                       dev->gc_dirtiest, dev->gc_pages_in_use,
+                       dev->oldest_dirty_block, background ? " bg" : "");
+       }
+
+       return selected;
+}
+
+/* New garbage collector
+ * If we're very low on erased blocks then we do aggressive garbage collection
+ * otherwise we do "leasurely" garbage collection.
+ * Aggressive gc looks further (whole array) and will accept less dirty blocks.
+ * Passive gc only inspects smaller areas and will only accept more dirty blocks.
+ *
+ * The idea is to help clear out space in a more spread-out manner.
+ * Dunno if it really does anything useful.
+ */
+static int yaffs_check_gc(struct yaffs_dev *dev, int background)
+{
+       int aggressive = 0;
+       int gc_ok = YAFFS_OK;
+       int max_tries = 0;
+       int min_erased;
+       int erased_chunks;
+       int checkpt_block_adjust;
+
+       if (dev->param.gc_control && (dev->param.gc_control(dev) & 1) == 0)
+               return YAFFS_OK;
+
+       if (dev->gc_disable) {
+               /* Bail out so we don't get recursive gc */
+               return YAFFS_OK;
+       }
+
+       /* This loop should pass the first time.
+        * We'll only see looping here if the collection does not increase space.
+        */
+
+       do {
+               max_tries++;
+
+               checkpt_block_adjust = yaffs_calc_checkpt_blocks_required(dev);
+
+               min_erased =
+                   dev->param.n_reserved_blocks + checkpt_block_adjust + 1;
+               erased_chunks =
+                   dev->n_erased_blocks * dev->param.chunks_per_block;
+
+               /* If we need a block soon then do aggressive gc. */
+               if (dev->n_erased_blocks < min_erased)
+                       aggressive = 1;
+               else {
+                       if (!background
+                           && erased_chunks > (dev->n_free_chunks / 4))
+                               break;
+
+                       if (dev->gc_skip > 20)
+                               dev->gc_skip = 20;
+                       if (erased_chunks < dev->n_free_chunks / 2 ||
+                           dev->gc_skip < 1 || background)
+                               aggressive = 0;
+                       else {
+                               dev->gc_skip--;
+                               break;
+                       }
+               }
+
+               dev->gc_skip = 5;
+
+               /* If we don't already have a block being gc'd then see if we should start another */
+
+               if (dev->gc_block < 1 && !aggressive) {
+                       dev->gc_block = yaffs2_find_refresh_block(dev);
+                       dev->gc_chunk = 0;
+                       dev->n_clean_ups = 0;
+               }
+               if (dev->gc_block < 1) {
+                       dev->gc_block =
+                           yaffs_find_gc_block(dev, aggressive, background);
+                       dev->gc_chunk = 0;
+                       dev->n_clean_ups = 0;
+               }
+
+               if (dev->gc_block > 0) {
+                       dev->all_gcs++;
+                       if (!aggressive)
+                               dev->passive_gc_count++;
+
+                       yaffs_trace(YAFFS_TRACE_GC,
+                               "yaffs: GC n_erased_blocks %d aggressive %d",
+                               dev->n_erased_blocks, aggressive);
+
+                       gc_ok = yaffs_gc_block(dev, dev->gc_block, aggressive);
+               }
+
+               if (dev->n_erased_blocks < (dev->param.n_reserved_blocks)
+                   && dev->gc_block > 0) {
+                       yaffs_trace(YAFFS_TRACE_GC,
+                               "yaffs: GC !!!no reclaim!!! n_erased_blocks %d after try %d block %d",
+                               dev->n_erased_blocks, max_tries,
+                               dev->gc_block);
+               }
+       } while ((dev->n_erased_blocks < dev->param.n_reserved_blocks) &&
+                (dev->gc_block > 0) && (max_tries < 2));
+
+       return aggressive ? gc_ok : YAFFS_OK;
+}
+
+/*
+ * yaffs_bg_gc()
+ * Garbage collects. Intended to be called from a background thread.
+ * Returns non-zero if at least half the free chunks are erased.
+ */
+int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency)
+{
+       int erased_chunks = dev->n_erased_blocks * dev->param.chunks_per_block;
+
+       yaffs_trace(YAFFS_TRACE_BACKGROUND, "Background gc %u", urgency);
+
+       yaffs_check_gc(dev, 1);
+       return erased_chunks > dev->n_free_chunks / 2;
+}
+
+/*-------------------- Data file manipulation -----------------*/
+
+static int yaffs_rd_data_obj(struct yaffs_obj *in, int inode_chunk, u8 * buffer)
+{
+       int nand_chunk = yaffs_find_chunk_in_file(in, inode_chunk, NULL);
+
+       if (nand_chunk >= 0)
+               return yaffs_rd_chunk_tags_nand(in->my_dev, nand_chunk,
+                                               buffer, NULL);
+       else {
+               yaffs_trace(YAFFS_TRACE_NANDACCESS,
+                       "Chunk %d not found zero instead",
+                       nand_chunk);
+               /* get sane (zero) data if you read a hole */
+               memset(buffer, 0, in->my_dev->data_bytes_per_chunk);
+               return 0;
+       }
+
+}
+
+void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
+                    int lyn)
+{
+       int block;
+       int page;
+       struct yaffs_ext_tags tags;
+       struct yaffs_block_info *bi;
+
+       if (chunk_id <= 0)
+               return;
+
+       dev->n_deletions++;
+       block = chunk_id / dev->param.chunks_per_block;
+       page = chunk_id % dev->param.chunks_per_block;
+
+       if (!yaffs_check_chunk_bit(dev, block, page))
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Deleting invalid chunk %d", chunk_id);
+
+       bi = yaffs_get_block_info(dev, block);
+
+       yaffs2_update_oldest_dirty_seq(dev, block, bi);
+
+       yaffs_trace(YAFFS_TRACE_DELETION,
+               "line %d delete of chunk %d",
+               lyn, chunk_id);
+
+       if (!dev->param.is_yaffs2 && mark_flash &&
+           bi->block_state != YAFFS_BLOCK_STATE_COLLECTING) {
+
+               yaffs_init_tags(&tags);
+
+               tags.is_deleted = 1;
+
+               yaffs_wr_chunk_tags_nand(dev, chunk_id, NULL, &tags);
+               yaffs_handle_chunk_update(dev, chunk_id, &tags);
+       } else {
+               dev->n_unmarked_deletions++;
+       }
+
+       /* Pull out of the management area.
+        * If the whole block became dirty, this will kick off an erasure.
+        */
+       if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING ||
+           bi->block_state == YAFFS_BLOCK_STATE_FULL ||
+           bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
+           bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
+               dev->n_free_chunks++;
+
+               yaffs_clear_chunk_bit(dev, block, page);
+
+               bi->pages_in_use--;
+
+               if (bi->pages_in_use == 0 &&
+                   !bi->has_shrink_hdr &&
+                   bi->block_state != YAFFS_BLOCK_STATE_ALLOCATING &&
+                   bi->block_state != YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
+                       yaffs_block_became_dirty(dev, block);
+               }
+
+       }
+
+}
+
+static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
+                            const u8 * buffer, int n_bytes, int use_reserve)
+{
+       /* Find old chunk Need to do this to get serial number
+        * Write new one and patch into tree.
+        * Invalidate old tags.
+        */
+
+       int prev_chunk_id;
+       struct yaffs_ext_tags prev_tags;
+
+       int new_chunk_id;
+       struct yaffs_ext_tags new_tags;
+
+       struct yaffs_dev *dev = in->my_dev;
+
+       yaffs_check_gc(dev, 0);
+
+       /* Get the previous chunk at this location in the file if it exists.
+        * If it does not exist then put a zero into the tree. This creates
+        * the tnode now, rather than later when it is harder to clean up.
+        */
+       prev_chunk_id = yaffs_find_chunk_in_file(in, inode_chunk, &prev_tags);
+       if (prev_chunk_id < 1 &&
+           !yaffs_put_chunk_in_file(in, inode_chunk, 0, 0))
+               return 0;
+
+       /* Set up new tags */
+       yaffs_init_tags(&new_tags);
+
+       new_tags.chunk_id = inode_chunk;
+       new_tags.obj_id = in->obj_id;
+       new_tags.serial_number =
+           (prev_chunk_id > 0) ? prev_tags.serial_number + 1 : 1;
+       new_tags.n_bytes = n_bytes;
+
+       if (n_bytes < 1 || n_bytes > dev->param.total_bytes_per_chunk) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                 "Writing %d bytes to chunk!!!!!!!!!",
+                  n_bytes);
+               YBUG();
+       }
+
+       new_chunk_id =
+           yaffs_write_new_chunk(dev, buffer, &new_tags, use_reserve);
+
+       if (new_chunk_id > 0) {
+               yaffs_put_chunk_in_file(in, inode_chunk, new_chunk_id, 0);
+
+               if (prev_chunk_id > 0)
+                       yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
+
+               yaffs_verify_file_sane(in);
+       }
+       return new_chunk_id;
+
+}
+
+
+
+static int yaffs_do_xattrib_mod(struct yaffs_obj *obj, int set,
+                               const YCHAR * name, const void *value, int size,
+                               int flags)
+{
+       struct yaffs_xattr_mod xmod;
+
+       int result;
+
+       xmod.set = set;
+       xmod.name = name;
+       xmod.data = value;
+       xmod.size = size;
+       xmod.flags = flags;
+       xmod.result = -ENOSPC;
+
+       result = yaffs_update_oh(obj, NULL, 0, 0, 0, &xmod);
+
+       if (result > 0)
+               return xmod.result;
+       else
+               return -ENOSPC;
+}
+
+static int yaffs_apply_xattrib_mod(struct yaffs_obj *obj, char *buffer,
+                                  struct yaffs_xattr_mod *xmod)
+{
+       int retval = 0;
+       int x_offs = sizeof(struct yaffs_obj_hdr);
+       struct yaffs_dev *dev = obj->my_dev;
+       int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
+
+       char *x_buffer = buffer + x_offs;
+
+       if (xmod->set)
+               retval =
+                   nval_set(x_buffer, x_size, xmod->name, xmod->data,
+                            xmod->size, xmod->flags);
+       else
+               retval = nval_del(x_buffer, x_size, xmod->name);
+
+       obj->has_xattr = nval_hasvalues(x_buffer, x_size);
+       obj->xattr_known = 1;
+
+       xmod->result = retval;
+
+       return retval;
+}
+
+static int yaffs_do_xattrib_fetch(struct yaffs_obj *obj, const YCHAR * name,
+                                 void *value, int size)
+{
+       char *buffer = NULL;
+       int result;
+       struct yaffs_ext_tags tags;
+       struct yaffs_dev *dev = obj->my_dev;
+       int x_offs = sizeof(struct yaffs_obj_hdr);
+       int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
+
+       char *x_buffer;
+
+       int retval = 0;
+
+       if (obj->hdr_chunk < 1)
+               return -ENODATA;
+
+       /* If we know that the object has no xattribs then don't do all the
+        * reading and parsing.
+        */
+       if (obj->xattr_known && !obj->has_xattr) {
+               if (name)
+                       return -ENODATA;
+               else
+                       return 0;
+       }
+
+       buffer = (char *)yaffs_get_temp_buffer(dev, __LINE__);
+       if (!buffer)
+               return -ENOMEM;
+
+       result =
+           yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, (u8 *) buffer, &tags);
+
+       if (result != YAFFS_OK)
+               retval = -ENOENT;
+       else {
+               x_buffer = buffer + x_offs;
+
+               if (!obj->xattr_known) {
+                       obj->has_xattr = nval_hasvalues(x_buffer, x_size);
+                       obj->xattr_known = 1;
+               }
+
+               if (name)
+                       retval = nval_get(x_buffer, x_size, name, value, size);
+               else
+                       retval = nval_list(x_buffer, x_size, value, size);
+       }
+       yaffs_release_temp_buffer(dev, (u8 *) buffer, __LINE__);
+       return retval;
+}
+
+int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
+                     const void *value, int size, int flags)
+{
+       return yaffs_do_xattrib_mod(obj, 1, name, value, size, flags);
+}
+
+int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name)
+{
+       return yaffs_do_xattrib_mod(obj, 0, name, NULL, 0, 0);
+}
+
+int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
+                     int size)
+{
+       return yaffs_do_xattrib_fetch(obj, name, value, size);
+}
+
+int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size)
+{
+       return yaffs_do_xattrib_fetch(obj, NULL, buffer, size);
+}
+
+static void yaffs_check_obj_details_loaded(struct yaffs_obj *in)
+{
+       u8 *chunk_data;
+       struct yaffs_obj_hdr *oh;
+       struct yaffs_dev *dev;
+       struct yaffs_ext_tags tags;
+       int result;
+       int alloc_failed = 0;
+
+       if (!in)
+               return;
+
+       dev = in->my_dev;
+
+       if (in->lazy_loaded && in->hdr_chunk > 0) {
+               in->lazy_loaded = 0;
+               chunk_data = yaffs_get_temp_buffer(dev, __LINE__);
+
+               result =
+                   yaffs_rd_chunk_tags_nand(dev, in->hdr_chunk, chunk_data,
+                                            &tags);
+               oh = (struct yaffs_obj_hdr *)chunk_data;
+
+               in->yst_mode = oh->yst_mode;
+               yaffs_load_attribs(in, oh);
+               yaffs_set_obj_name_from_oh(in, oh);
+
+               if (in->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
+                       in->variant.symlink_variant.alias =
+                           yaffs_clone_str(oh->alias);
+                       if (!in->variant.symlink_variant.alias)
+                               alloc_failed = 1;       /* Not returned to caller */
+               }
+
+               yaffs_release_temp_buffer(dev, chunk_data, __LINE__);
+       }
+}
+
+static void yaffs_load_name_from_oh(struct yaffs_dev *dev, YCHAR * name,
+                                   const YCHAR * oh_name, int buff_size)
+{
+#ifdef CONFIG_YAFFS_AUTO_UNICODE
+       if (dev->param.auto_unicode) {
+               if (*oh_name) {
+                       /* It is an ASCII name, do an ASCII to
+                        * unicode conversion */
+                       const char *ascii_oh_name = (const char *)oh_name;
+                       int n = buff_size - 1;
+                       while (n > 0 && *ascii_oh_name) {
+                               *name = *ascii_oh_name;
+                               name++;
+                               ascii_oh_name++;
+                               n--;
+                       }
+               } else {
+                       strncpy(name, oh_name + 1, buff_size - 1);
+                }
+       } else {
+#else
+        {
+#endif
+               strncpy(name, oh_name, buff_size - 1);
+        }
+}
+
+static void yaffs_load_oh_from_name(struct yaffs_dev *dev, YCHAR * oh_name,
+                                   const YCHAR * name)
+{
+#ifdef CONFIG_YAFFS_AUTO_UNICODE
+
+       int is_ascii;
+       YCHAR *w;
+
+       if (dev->param.auto_unicode) {
+
+               is_ascii = 1;
+               w = name;
+
+               /* Figure out if the name will fit in ascii character set */
+               while (is_ascii && *w) {
+                       if ((*w) & 0xff00)
+                               is_ascii = 0;
+                       w++;
+               }
+
+               if (is_ascii) {
+                       /* It is an ASCII name, so do a unicode to ascii conversion */
+                       char *ascii_oh_name = (char *)oh_name;
+                       int n = YAFFS_MAX_NAME_LENGTH - 1;
+                       while (n > 0 && *name) {
+                               *ascii_oh_name = *name;
+                               name++;
+                               ascii_oh_name++;
+                               n--;
+                       }
+               } else {
+                       /* It is a unicode name, so save starting at the second YCHAR */
+                       *oh_name = 0;
+                       strncpy(oh_name + 1, name,
+                                     YAFFS_MAX_NAME_LENGTH - 2);
+               }
+       } else {
+#else
+        {
+#endif
+               strncpy(oh_name, name, YAFFS_MAX_NAME_LENGTH - 1);
+        }
+
+}
+
+/* UpdateObjectHeader updates the header on NAND for an object.
+ * If name is not NULL, then that new name is used.
+ */
+int yaffs_update_oh(struct yaffs_obj *in, const YCHAR * name, int force,
+                   int is_shrink, int shadows, struct yaffs_xattr_mod *xmod)
+{
+
+       struct yaffs_block_info *bi;
+
+       struct yaffs_dev *dev = in->my_dev;
+
+       int prev_chunk_id;
+       int ret_val = 0;
+       int result = 0;
+
+       int new_chunk_id;
+       struct yaffs_ext_tags new_tags;
+       struct yaffs_ext_tags old_tags;
+       const YCHAR *alias = NULL;
+
+       u8 *buffer = NULL;
+       YCHAR old_name[YAFFS_MAX_NAME_LENGTH + 1];
+
+       struct yaffs_obj_hdr *oh = NULL;
+
+       strcpy(old_name, _Y("silly old name"));
+
+       if (!in->fake || in == dev->root_dir ||
+           force || xmod) {
+
+               yaffs_check_gc(dev, 0);
+               yaffs_check_obj_details_loaded(in);
+
+               buffer = yaffs_get_temp_buffer(in->my_dev, __LINE__);
+               oh = (struct yaffs_obj_hdr *)buffer;
+
+               prev_chunk_id = in->hdr_chunk;
+
+               if (prev_chunk_id > 0) {
+                       result = yaffs_rd_chunk_tags_nand(dev, prev_chunk_id,
+                                                         buffer, &old_tags);
+
+                       yaffs_verify_oh(in, oh, &old_tags, 0);
+
+                       memcpy(old_name, oh->name, sizeof(oh->name));
+                       memset(buffer, 0xFF, sizeof(struct yaffs_obj_hdr));
+               } else {
+                       memset(buffer, 0xFF, dev->data_bytes_per_chunk);
+                }
+
+               oh->type = in->variant_type;
+               oh->yst_mode = in->yst_mode;
+               oh->shadows_obj = oh->inband_shadowed_obj_id = shadows;
+
+               yaffs_load_attribs_oh(oh, in);
+
+               if (in->parent)
+                       oh->parent_obj_id = in->parent->obj_id;
+               else
+                       oh->parent_obj_id = 0;
+
+               if (name && *name) {
+                       memset(oh->name, 0, sizeof(oh->name));
+                       yaffs_load_oh_from_name(dev, oh->name, name);
+               } else if (prev_chunk_id > 0) {
+                       memcpy(oh->name, old_name, sizeof(oh->name));
+               } else {
+                       memset(oh->name, 0, sizeof(oh->name));
+                }
+
+               oh->is_shrink = is_shrink;
+
+               switch (in->variant_type) {
+               case YAFFS_OBJECT_TYPE_UNKNOWN:
+                       /* Should not happen */
+                       break;
+               case YAFFS_OBJECT_TYPE_FILE:
+                       oh->file_size =
+                           (oh->parent_obj_id == YAFFS_OBJECTID_DELETED
+                            || oh->parent_obj_id ==
+                            YAFFS_OBJECTID_UNLINKED) ? 0 : in->
+                           variant.file_variant.file_size;
+                       break;
+               case YAFFS_OBJECT_TYPE_HARDLINK:
+                       oh->equiv_id = in->variant.hardlink_variant.equiv_id;
+                       break;
+               case YAFFS_OBJECT_TYPE_SPECIAL:
+                       /* Do nothing */
+                       break;
+               case YAFFS_OBJECT_TYPE_DIRECTORY:
+                       /* Do nothing */
+                       break;
+               case YAFFS_OBJECT_TYPE_SYMLINK:
+                       alias = in->variant.symlink_variant.alias;
+                       if (!alias)
+                               alias = _Y("no alias");
+                       strncpy(oh->alias, alias, YAFFS_MAX_ALIAS_LENGTH);
+                       oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
+                       break;
+               }
+
+               /* process any xattrib modifications */
+               if (xmod)
+                       yaffs_apply_xattrib_mod(in, (char *)buffer, xmod);
+
+               /* Tags */
+               yaffs_init_tags(&new_tags);
+               in->serial++;
+               new_tags.chunk_id = 0;
+               new_tags.obj_id = in->obj_id;
+               new_tags.serial_number = in->serial;
+
+               /* Add extra info for file header */
+
+               new_tags.extra_available = 1;
+               new_tags.extra_parent_id = oh->parent_obj_id;
+               new_tags.extra_length = oh->file_size;
+               new_tags.extra_is_shrink = oh->is_shrink;
+               new_tags.extra_equiv_id = oh->equiv_id;
+               new_tags.extra_shadows = (oh->shadows_obj > 0) ? 1 : 0;
+               new_tags.extra_obj_type = in->variant_type;
+
+               yaffs_verify_oh(in, oh, &new_tags, 1);
+
+               /* Create new chunk in NAND */
+               new_chunk_id =
+                   yaffs_write_new_chunk(dev, buffer, &new_tags,
+                                         (prev_chunk_id > 0) ? 1 : 0);
+
+               if (new_chunk_id >= 0) {
+
+                       in->hdr_chunk = new_chunk_id;
+
+                       if (prev_chunk_id > 0) {
+                               yaffs_chunk_del(dev, prev_chunk_id, 1,
+                                               __LINE__);
+                       }
+
+                       if (!yaffs_obj_cache_dirty(in))
+                               in->dirty = 0;
+
+                       /* If this was a shrink, then mark the block that the chunk lives on */
+                       if (is_shrink) {
+                               bi = yaffs_get_block_info(in->my_dev,
+                                                         new_chunk_id /
+                                                         in->my_dev->param.
+                                                         chunks_per_block);
+                               bi->has_shrink_hdr = 1;
+                       }
+
+               }
+
+               ret_val = new_chunk_id;
+
+       }
+
+       if (buffer)
+               yaffs_release_temp_buffer(dev, buffer, __LINE__);
+
+       return ret_val;
+}
+
+/*--------------------- File read/write ------------------------
+ * Read and write have very similar structures.
+ * In general the read/write has three parts to it
+ * An incomplete chunk to start with (if the read/write is not chunk-aligned)
+ * Some complete chunks
+ * An incomplete chunk to end off with
+ *
+ * Curve-balls: the first chunk might also be the last chunk.
+ */
+
+int yaffs_file_rd(struct yaffs_obj *in, u8 * buffer, loff_t offset, int n_bytes)
+{
+
+       int chunk;
+       u32 start;
+       int n_copy;
+       int n = n_bytes;
+       int n_done = 0;
+       struct yaffs_cache *cache;
+
+       struct yaffs_dev *dev;
+
+       dev = in->my_dev;
+
+       while (n > 0) {
+               /* chunk = offset / dev->data_bytes_per_chunk + 1; */
+               /* start = offset % dev->data_bytes_per_chunk; */
+               yaffs_addr_to_chunk(dev, offset, &chunk, &start);
+               chunk++;
+
+               /* OK now check for the curveball where the start and end are in
+                * the same chunk.
+                */
+               if ((start + n) < dev->data_bytes_per_chunk)
+                       n_copy = n;
+               else
+                       n_copy = dev->data_bytes_per_chunk - start;
+
+               cache = yaffs_find_chunk_cache(in, chunk);
+
+               /* If the chunk is already in the cache or it is less than a whole chunk
+                * or we're using inband tags then use the cache (if there is caching)
+                * else bypass the cache.
+                */
+               if (cache || n_copy != dev->data_bytes_per_chunk
+                   || dev->param.inband_tags) {
+                       if (dev->param.n_caches > 0) {
+
+                               /* If we can't find the data in the cache, then load it up. */
+
+                               if (!cache) {
+                                       cache =
+                                           yaffs_grab_chunk_cache(in->my_dev);
+                                       cache->object = in;
+                                       cache->chunk_id = chunk;
+                                       cache->dirty = 0;
+                                       cache->locked = 0;
+                                       yaffs_rd_data_obj(in, chunk,
+                                                         cache->data);
+                                       cache->n_bytes = 0;
+                               }
+
+                               yaffs_use_cache(dev, cache, 0);
+
+                               cache->locked = 1;
+
+                               memcpy(buffer, &cache->data[start], n_copy);
+
+                               cache->locked = 0;
+                       } else {
+                               /* Read into the local buffer then copy.. */
+
+                               u8 *local_buffer =
+                                   yaffs_get_temp_buffer(dev, __LINE__);
+                               yaffs_rd_data_obj(in, chunk, local_buffer);
+
+                               memcpy(buffer, &local_buffer[start], n_copy);
+
+                               yaffs_release_temp_buffer(dev, local_buffer,
+                                                         __LINE__);
+                       }
+
+               } else {
+
+                       /* A full chunk. Read directly into the supplied buffer. */
+                       yaffs_rd_data_obj(in, chunk, buffer);
+
+               }
+
+               n -= n_copy;
+               offset += n_copy;
+               buffer += n_copy;
+               n_done += n_copy;
+
+       }
+
+       return n_done;
+}
+
+int yaffs_do_file_wr(struct yaffs_obj *in, const u8 * buffer, loff_t offset,
+                    int n_bytes, int write_trhrough)
+{
+
+       int chunk;
+       u32 start;
+       int n_copy;
+       int n = n_bytes;
+       int n_done = 0;
+       int n_writeback;
+       int start_write = offset;
+       int chunk_written = 0;
+       u32 n_bytes_read;
+       u32 chunk_start;
+
+       struct yaffs_dev *dev;
+
+       dev = in->my_dev;
+
+       while (n > 0 && chunk_written >= 0) {
+               yaffs_addr_to_chunk(dev, offset, &chunk, &start);
+
+               if (chunk * dev->data_bytes_per_chunk + start != offset ||
+                   start >= dev->data_bytes_per_chunk) {
+                       yaffs_trace(YAFFS_TRACE_ERROR,
+                               "AddrToChunk of offset %d gives chunk %d start %d",
+                               (int)offset, chunk, start);
+               }
+               chunk++;        /* File pos to chunk in file offset */
+
+               /* OK now check for the curveball where the start and end are in
+                * the same chunk.
+                */
+
+               if ((start + n) < dev->data_bytes_per_chunk) {
+                       n_copy = n;
+
+                       /* Now folks, to calculate how many bytes to write back....
+                        * If we're overwriting and not writing to then end of file then
+                        * we need to write back as much as was there before.
+                        */
+
+                       chunk_start = ((chunk - 1) * dev->data_bytes_per_chunk);
+
+                       if (chunk_start > in->variant.file_variant.file_size)
+                               n_bytes_read = 0;       /* Past end of file */
+                       else
+                               n_bytes_read =
+                                   in->variant.file_variant.file_size -
+                                   chunk_start;
+
+                       if (n_bytes_read > dev->data_bytes_per_chunk)
+                               n_bytes_read = dev->data_bytes_per_chunk;
+
+                       n_writeback =
+                           (n_bytes_read >
+                            (start + n)) ? n_bytes_read : (start + n);
+
+                       if (n_writeback < 0
+                           || n_writeback > dev->data_bytes_per_chunk)
+                               YBUG();
+
+               } else {
+                       n_copy = dev->data_bytes_per_chunk - start;
+                       n_writeback = dev->data_bytes_per_chunk;
+               }
+
+               if (n_copy != dev->data_bytes_per_chunk
+                   || dev->param.inband_tags) {
+                       /* An incomplete start or end chunk (or maybe both start and end chunk),
+                        * or we're using inband tags, so we want to use the cache buffers.
+                        */
+                       if (dev->param.n_caches > 0) {
+                               struct yaffs_cache *cache;
+                               /* If we can't find the data in the cache, then load the cache */
+                               cache = yaffs_find_chunk_cache(in, chunk);
+
+                               if (!cache
+                                   && yaffs_check_alloc_available(dev, 1)) {
+                                       cache = yaffs_grab_chunk_cache(dev);
+                                       cache->object = in;
+                                       cache->chunk_id = chunk;
+                                       cache->dirty = 0;
+                                       cache->locked = 0;
+                                       yaffs_rd_data_obj(in, chunk,
+                                                         cache->data);
+                               } else if (cache &&
+                                          !cache->dirty &&
+                                          !yaffs_check_alloc_available(dev,
+                                                                       1)) {
+                                       /* Drop the cache if it was a read cache item and
+                                        * no space check has been made for it.
+                                        */
+                                       cache = NULL;
+                               }
+
+                               if (cache) {
+                                       yaffs_use_cache(dev, cache, 1);
+                                       cache->locked = 1;
+
+                                       memcpy(&cache->data[start], buffer,
+                                              n_copy);
+
+                                       cache->locked = 0;
+                                       cache->n_bytes = n_writeback;
+
+                                       if (write_trhrough) {
+                                               chunk_written =
+                                                   yaffs_wr_data_obj
+                                                   (cache->object,
+                                                    cache->chunk_id,
+                                                    cache->data,
+                                                    cache->n_bytes, 1);
+                                               cache->dirty = 0;
+                                       }
+
+                               } else {
+                                       chunk_written = -1;     /* fail the write */
+                               }
+                       } else {
+                               /* An incomplete start or end chunk (or maybe both start and end chunk)
+                                * Read into the local buffer then copy, then copy over and write back.
+                                */
+
+                               u8 *local_buffer =
+                                   yaffs_get_temp_buffer(dev, __LINE__);
+
+                               yaffs_rd_data_obj(in, chunk, local_buffer);
+
+                               memcpy(&local_buffer[start], buffer, n_copy);
+
+                               chunk_written =
+                                   yaffs_wr_data_obj(in, chunk,
+                                                     local_buffer,
+                                                     n_writeback, 0);
+
+                               yaffs_release_temp_buffer(dev, local_buffer,
+                                                         __LINE__);
+
+                       }
+
+               } else {
+                       /* A full chunk. Write directly from the supplied buffer. */
+
+                       chunk_written =
+                           yaffs_wr_data_obj(in, chunk, buffer,
+                                             dev->data_bytes_per_chunk, 0);
+
+                       /* Since we've overwritten the cached data, we better invalidate it. */
+                       yaffs_invalidate_chunk_cache(in, chunk);
+               }
+
+               if (chunk_written >= 0) {
+                       n -= n_copy;
+                       offset += n_copy;
+                       buffer += n_copy;
+                       n_done += n_copy;
+               }
+
+       }
+
+       /* Update file object */
+
+       if ((start_write + n_done) > in->variant.file_variant.file_size)
+               in->variant.file_variant.file_size = (start_write + n_done);
+
+       in->dirty = 1;
+
+       return n_done;
+}
+
+int yaffs_wr_file(struct yaffs_obj *in, const u8 * buffer, loff_t offset,
+                 int n_bytes, int write_trhrough)
+{
+       yaffs2_handle_hole(in, offset);
+       return yaffs_do_file_wr(in, buffer, offset, n_bytes, write_trhrough);
+}
+
+/* ---------------------- File resizing stuff ------------------ */
+
+static void yaffs_prune_chunks(struct yaffs_obj *in, int new_size)
+{
+
+       struct yaffs_dev *dev = in->my_dev;
+       int old_size = in->variant.file_variant.file_size;
+
+       int last_del = 1 + (old_size - 1) / dev->data_bytes_per_chunk;
+
+       int start_del = 1 + (new_size + dev->data_bytes_per_chunk - 1) /
+           dev->data_bytes_per_chunk;
+       int i;
+       int chunk_id;
+
+       /* Delete backwards so that we don't end up with holes if
+        * power is lost part-way through the operation.
+        */
+       for (i = last_del; i >= start_del; i--) {
+               /* NB this could be optimised somewhat,
+                * eg. could retrieve the tags and write them without
+                * using yaffs_chunk_del
+                */
+
+               chunk_id = yaffs_find_del_file_chunk(in, i, NULL);
+               if (chunk_id > 0) {
+                       if (chunk_id <
+                           (dev->internal_start_block *
+                            dev->param.chunks_per_block)
+                           || chunk_id >=
+                           ((dev->internal_end_block +
+                             1) * dev->param.chunks_per_block)) {
+                               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                                       "Found daft chunk_id %d for %d",
+                                       chunk_id, i);
+                       } else {
+                               in->n_data_chunks--;
+                               yaffs_chunk_del(dev, chunk_id, 1, __LINE__);
+                       }
+               }
+       }
+
+}
+
+void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size)
+{
+       int new_full;
+       u32 new_partial;
+       struct yaffs_dev *dev = obj->my_dev;
+
+       yaffs_addr_to_chunk(dev, new_size, &new_full, &new_partial);
+
+       yaffs_prune_chunks(obj, new_size);
+
+       if (new_partial != 0) {
+               int last_chunk = 1 + new_full;
+               u8 *local_buffer = yaffs_get_temp_buffer(dev, __LINE__);
+
+               /* Rewrite the last chunk with its new size and zero pad */
+               yaffs_rd_data_obj(obj, last_chunk, local_buffer);
+               memset(local_buffer + new_partial, 0,
+                      dev->data_bytes_per_chunk - new_partial);
+
+               yaffs_wr_data_obj(obj, last_chunk, local_buffer,
+                                 new_partial, 1);
+
+               yaffs_release_temp_buffer(dev, local_buffer, __LINE__);
+       }
+
+       obj->variant.file_variant.file_size = new_size;
+
+       yaffs_prune_tree(dev, &obj->variant.file_variant);
+}
+
+int yaffs_resize_file(struct yaffs_obj *in, loff_t new_size)
+{
+       struct yaffs_dev *dev = in->my_dev;
+       int old_size = in->variant.file_variant.file_size;
+
+       yaffs_flush_file_cache(in);
+       yaffs_invalidate_whole_cache(in);
+
+       yaffs_check_gc(dev, 0);
+
+       if (in->variant_type != YAFFS_OBJECT_TYPE_FILE)
+               return YAFFS_FAIL;
+
+       if (new_size == old_size)
+               return YAFFS_OK;
+
+       if (new_size > old_size) {
+               yaffs2_handle_hole(in, new_size);
+               in->variant.file_variant.file_size = new_size;
+       } else {
+               /* new_size < old_size */
+               yaffs_resize_file_down(in, new_size);
+       }
+
+       /* Write a new object header to reflect the resize.
+        * show we've shrunk the file, if need be
+        * Do this only if the file is not in the deleted directories
+        * and is not shadowed.
+        */
+       if (in->parent &&
+           !in->is_shadowed &&
+           in->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
+           in->parent->obj_id != YAFFS_OBJECTID_DELETED)
+               yaffs_update_oh(in, NULL, 0, 0, 0, NULL);
+
+       return YAFFS_OK;
+}
+
+int yaffs_flush_file(struct yaffs_obj *in, int update_time, int data_sync)
+{
+       int ret_val;
+       if (in->dirty) {
+               yaffs_flush_file_cache(in);
+               if (data_sync)  /* Only sync data */
+                       ret_val = YAFFS_OK;
+               else {
+                       if (update_time)
+                               yaffs_load_current_time(in, 0, 0);
+
+                       ret_val = (yaffs_update_oh(in, NULL, 0, 0, 0, NULL) >=
+                                  0) ? YAFFS_OK : YAFFS_FAIL;
+               }
+       } else {
+               ret_val = YAFFS_OK;
+       }
+
+       return ret_val;
+
+}
+
+
+/* yaffs_del_file deletes the whole file data
+ * and the inode associated with the file.
+ * It does not delete the links associated with the file.
+ */
+static int yaffs_unlink_file_if_needed(struct yaffs_obj *in)
+{
+
+       int ret_val;
+       int del_now = 0;
+       struct yaffs_dev *dev = in->my_dev;
+
+       if (!in->my_inode)
+               del_now = 1;
+
+       if (del_now) {
+               ret_val =
+                   yaffs_change_obj_name(in, in->my_dev->del_dir,
+                                         _Y("deleted"), 0, 0);
+               yaffs_trace(YAFFS_TRACE_TRACING,
+                       "yaffs: immediate deletion of file %d",
+                       in->obj_id);
+               in->deleted = 1;
+               in->my_dev->n_deleted_files++;
+               if (dev->param.disable_soft_del || dev->param.is_yaffs2)
+                       yaffs_resize_file(in, 0);
+               yaffs_soft_del_file(in);
+       } else {
+               ret_val =
+                   yaffs_change_obj_name(in, in->my_dev->unlinked_dir,
+                                         _Y("unlinked"), 0, 0);
+       }
+
+       return ret_val;
+}
+
+int yaffs_del_file(struct yaffs_obj *in)
+{
+       int ret_val = YAFFS_OK;
+       int deleted;            /* Need to cache value on stack if in is freed */
+       struct yaffs_dev *dev = in->my_dev;
+
+       if (dev->param.disable_soft_del || dev->param.is_yaffs2)
+               yaffs_resize_file(in, 0);
+
+       if (in->n_data_chunks > 0) {
+               /* Use soft deletion if there is data in the file.
+                * That won't be the case if it has been resized to zero.
+                */
+               if (!in->unlinked)
+                       ret_val = yaffs_unlink_file_if_needed(in);
+
+               deleted = in->deleted;
+
+               if (ret_val == YAFFS_OK && in->unlinked && !in->deleted) {
+                       in->deleted = 1;
+                       deleted = 1;
+                       in->my_dev->n_deleted_files++;
+                       yaffs_soft_del_file(in);
+               }
+               return deleted ? YAFFS_OK : YAFFS_FAIL;
+       } else {
+               /* The file has no data chunks so we toss it immediately */
+               yaffs_free_tnode(in->my_dev, in->variant.file_variant.top);
+               in->variant.file_variant.top = NULL;
+               yaffs_generic_obj_del(in);
+
+               return YAFFS_OK;
+       }
+}
+
+int yaffs_is_non_empty_dir(struct yaffs_obj *obj)
+{
+       return (obj &&
+               obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY) &&
+               !(list_empty(&obj->variant.dir_variant.children));
+}
+
+static int yaffs_del_dir(struct yaffs_obj *obj)
+{
+       /* First check that the directory is empty. */
+       if (yaffs_is_non_empty_dir(obj))
+               return YAFFS_FAIL;
+
+       return yaffs_generic_obj_del(obj);
+}
+
+static int yaffs_del_symlink(struct yaffs_obj *in)
+{
+       if (in->variant.symlink_variant.alias)
+               kfree(in->variant.symlink_variant.alias);
+       in->variant.symlink_variant.alias = NULL;
+
+       return yaffs_generic_obj_del(in);
+}
+
+static int yaffs_del_link(struct yaffs_obj *in)
+{
+       /* remove this hardlink from the list assocaited with the equivalent
+        * object
+        */
+       list_del_init(&in->hard_links);
+       return yaffs_generic_obj_del(in);
+}
+
+int yaffs_del_obj(struct yaffs_obj *obj)
+{
+       int ret_val = -1;
+       switch (obj->variant_type) {
+       case YAFFS_OBJECT_TYPE_FILE:
+               ret_val = yaffs_del_file(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_DIRECTORY:
+               if (!list_empty(&obj->variant.dir_variant.dirty)) {
+                       yaffs_trace(YAFFS_TRACE_BACKGROUND,
+                               "Remove object %d from dirty directories",
+                               obj->obj_id);
+                       list_del_init(&obj->variant.dir_variant.dirty);
+               }
+               return yaffs_del_dir(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_SYMLINK:
+               ret_val = yaffs_del_symlink(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_HARDLINK:
+               ret_val = yaffs_del_link(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_SPECIAL:
+               ret_val = yaffs_generic_obj_del(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_UNKNOWN:
+               ret_val = 0;
+               break;          /* should not happen. */
+       }
+
+       return ret_val;
+}
+
+static int yaffs_unlink_worker(struct yaffs_obj *obj)
+{
+
+       int del_now = 0;
+
+       if (!obj->my_inode)
+               del_now = 1;
+
+       if (obj)
+               yaffs_update_parent(obj->parent);
+
+       if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
+               return yaffs_del_link(obj);
+       } else if (!list_empty(&obj->hard_links)) {
+               /* Curve ball: We're unlinking an object that has a hardlink.
+                *
+                * This problem arises because we are not strictly following
+                * The Linux link/inode model.
+                *
+                * We can't really delete the object.
+                * Instead, we do the following:
+                * - Select a hardlink.
+                * - Unhook it from the hard links
+                * - Move it from its parent directory (so that the rename can work)
+                * - Rename the object to the hardlink's name.
+                * - Delete the hardlink
+                */
+
+               struct yaffs_obj *hl;
+               struct yaffs_obj *parent;
+               int ret_val;
+               YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
+
+               hl = list_entry(obj->hard_links.next, struct yaffs_obj,
+                               hard_links);
+
+               yaffs_get_obj_name(hl, name, YAFFS_MAX_NAME_LENGTH + 1);
+               parent = hl->parent;
+
+               list_del_init(&hl->hard_links);
+
+               yaffs_add_obj_to_dir(obj->my_dev->unlinked_dir, hl);
+
+               ret_val = yaffs_change_obj_name(obj, parent, name, 0, 0);
+
+               if (ret_val == YAFFS_OK)
+                       ret_val = yaffs_generic_obj_del(hl);
+
+               return ret_val;
+
+       } else if (del_now) {
+               switch (obj->variant_type) {
+               case YAFFS_OBJECT_TYPE_FILE:
+                       return yaffs_del_file(obj);
+                       break;
+               case YAFFS_OBJECT_TYPE_DIRECTORY:
+                       list_del_init(&obj->variant.dir_variant.dirty);
+                       return yaffs_del_dir(obj);
+                       break;
+               case YAFFS_OBJECT_TYPE_SYMLINK:
+                       return yaffs_del_symlink(obj);
+                       break;
+               case YAFFS_OBJECT_TYPE_SPECIAL:
+                       return yaffs_generic_obj_del(obj);
+                       break;
+               case YAFFS_OBJECT_TYPE_HARDLINK:
+               case YAFFS_OBJECT_TYPE_UNKNOWN:
+               default:
+                       return YAFFS_FAIL;
+               }
+       } else if (yaffs_is_non_empty_dir(obj)) {
+               return YAFFS_FAIL;
+       } else {
+               return yaffs_change_obj_name(obj, obj->my_dev->unlinked_dir,
+                                            _Y("unlinked"), 0, 0);
+        }
+}
+
+static int yaffs_unlink_obj(struct yaffs_obj *obj)
+{
+
+       if (obj && obj->unlink_allowed)
+               return yaffs_unlink_worker(obj);
+
+       return YAFFS_FAIL;
+
+}
+
+int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR * name)
+{
+       struct yaffs_obj *obj;
+
+       obj = yaffs_find_by_name(dir, name);
+       return yaffs_unlink_obj(obj);
+}
+
+/* Note:
+ * If old_name is NULL then we take old_dir as the object to be renamed.
+ */
+int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR * old_name,
+                    struct yaffs_obj *new_dir, const YCHAR * new_name)
+{
+       struct yaffs_obj *obj = NULL;
+       struct yaffs_obj *existing_target = NULL;
+       int force = 0;
+       int result;
+       struct yaffs_dev *dev;
+
+       if (!old_dir || old_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
+               YBUG();
+       if (!new_dir || new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
+               YBUG();
+
+       dev = old_dir->my_dev;
+
+#ifdef CONFIG_YAFFS_CASE_INSENSITIVE
+       /* Special case for case insemsitive systems.
+        * While look-up is case insensitive, the name isn't.
+        * Therefore we might want to change x.txt to X.txt
+        */
+       if (old_dir == new_dir && 
+               old_name && new_name && 
+               strcmp(old_name, new_name) == 0)
+               force = 1;
+#endif
+
+       if (strnlen(new_name, YAFFS_MAX_NAME_LENGTH + 1) >
+           YAFFS_MAX_NAME_LENGTH)
+               /* ENAMETOOLONG */
+               return YAFFS_FAIL;
+
+       if(old_name)
+               obj = yaffs_find_by_name(old_dir, old_name);
+       else{
+               obj = old_dir;
+               old_dir = obj->parent;
+       }
+
+
+       if (obj && obj->rename_allowed) {
+
+               /* Now do the handling for an existing target, if there is one */
+
+               existing_target = yaffs_find_by_name(new_dir, new_name);
+               if (yaffs_is_non_empty_dir(existing_target)){
+                       return YAFFS_FAIL;      /* ENOTEMPTY */
+               } else if (existing_target && existing_target != obj) {
+                       /* Nuke the target first, using shadowing,
+                        * but only if it isn't the same object.
+                        *
+                        * Note we must disable gc otherwise it can mess up the shadowing.
+                        *
+                        */
+                       dev->gc_disable = 1;
+                       yaffs_change_obj_name(obj, new_dir, new_name, force,
+                                             existing_target->obj_id);
+                       existing_target->is_shadowed = 1;
+                       yaffs_unlink_obj(existing_target);
+                       dev->gc_disable = 0;
+               }
+
+               result = yaffs_change_obj_name(obj, new_dir, new_name, 1, 0);
+
+               yaffs_update_parent(old_dir);
+               if (new_dir != old_dir)
+                       yaffs_update_parent(new_dir);
+
+               return result;
+       }
+       return YAFFS_FAIL;
+}
+
+/*----------------------- Initialisation Scanning ---------------------- */
+
+void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
+                              int backward_scanning)
+{
+       struct yaffs_obj *obj;
+
+       if (!backward_scanning) {
+               /* Handle YAFFS1 forward scanning case
+                * For YAFFS1 we always do the deletion
+                */
+
+       } else {
+               /* Handle YAFFS2 case (backward scanning)
+                * If the shadowed object exists then ignore.
+                */
+               obj = yaffs_find_by_number(dev, obj_id);
+               if (obj)
+                       return;
+       }
+
+       /* Let's create it (if it does not exist) assuming it is a file so that it can do shrinking etc.
+        * We put it in unlinked dir to be cleaned up after the scanning
+        */
+       obj =
+           yaffs_find_or_create_by_number(dev, obj_id, YAFFS_OBJECT_TYPE_FILE);
+       if (!obj)
+               return;
+       obj->is_shadowed = 1;
+       yaffs_add_obj_to_dir(dev->unlinked_dir, obj);
+       obj->variant.file_variant.shrink_size = 0;
+       obj->valid = 1;         /* So that we don't read any other info for this file */
+
+}
+
+void yaffs_link_fixup(struct yaffs_dev *dev, struct yaffs_obj *hard_list)
+{
+       struct yaffs_obj *hl;
+       struct yaffs_obj *in;
+
+       while (hard_list) {
+               hl = hard_list;
+               hard_list = (struct yaffs_obj *)(hard_list->hard_links.next);
+
+               in = yaffs_find_by_number(dev,
+                                         hl->variant.
+                                         hardlink_variant.equiv_id);
+
+               if (in) {
+                       /* Add the hardlink pointers */
+                       hl->variant.hardlink_variant.equiv_obj = in;
+                       list_add(&hl->hard_links, &in->hard_links);
+               } else {
+                       /* Todo Need to report/handle this better.
+                        * Got a problem... hardlink to a non-existant object
+                        */
+                       hl->variant.hardlink_variant.equiv_obj = NULL;
+                       INIT_LIST_HEAD(&hl->hard_links);
+
+               }
+       }
+}
+
+static void yaffs_strip_deleted_objs(struct yaffs_dev *dev)
+{
+       /*
+        *  Sort out state of unlinked and deleted objects after scanning.
+        */
+       struct list_head *i;
+       struct list_head *n;
+       struct yaffs_obj *l;
+
+       if (dev->read_only)
+               return;
+
+       /* Soft delete all the unlinked files */
+       list_for_each_safe(i, n,
+                          &dev->unlinked_dir->variant.dir_variant.children) {
+               if (i) {
+                       l = list_entry(i, struct yaffs_obj, siblings);
+                       yaffs_del_obj(l);
+               }
+       }
+
+       list_for_each_safe(i, n, &dev->del_dir->variant.dir_variant.children) {
+               if (i) {
+                       l = list_entry(i, struct yaffs_obj, siblings);
+                       yaffs_del_obj(l);
+               }
+       }
+
+}
+
+/*
+ * This code iterates through all the objects making sure that they are rooted.
+ * Any unrooted objects are re-rooted in lost+found.
+ * An object needs to be in one of:
+ * - Directly under deleted, unlinked
+ * - Directly or indirectly under root.
+ *
+ * Note:
+ *  This code assumes that we don't ever change the current relationships between
+ *  directories:
+ *   root_dir->parent == unlinked_dir->parent == del_dir->parent == NULL
+ *   lost-n-found->parent == root_dir
+ *
+ * This fixes the problem where directories might have inadvertently been deleted
+ * leaving the object "hanging" without being rooted in the directory tree.
+ */
+
+static int yaffs_has_null_parent(struct yaffs_dev *dev, struct yaffs_obj *obj)
+{
+       return (obj == dev->del_dir ||
+               obj == dev->unlinked_dir || obj == dev->root_dir);
+}
+
+static void yaffs_fix_hanging_objs(struct yaffs_dev *dev)
+{
+       struct yaffs_obj *obj;
+       struct yaffs_obj *parent;
+       int i;
+       struct list_head *lh;
+       struct list_head *n;
+       int depth_limit;
+       int hanging;
+
+       if (dev->read_only)
+               return;
+
+       /* Iterate through the objects in each hash entry,
+        * looking at each object.
+        * Make sure it is rooted.
+        */
+
+       for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
+               list_for_each_safe(lh, n, &dev->obj_bucket[i].list) {
+                       if (lh) {
+                               obj =
+                                   list_entry(lh, struct yaffs_obj, hash_link);
+                               parent = obj->parent;
+
+                               if (yaffs_has_null_parent(dev, obj)) {
+                                       /* These directories are not hanging */
+                                       hanging = 0;
+                               } else if (!parent
+                                          || parent->variant_type !=
+                                          YAFFS_OBJECT_TYPE_DIRECTORY) {
+                                       hanging = 1;
+                               } else if (yaffs_has_null_parent(dev, parent)) {
+                                       hanging = 0;
+                               } else {
+                                       /*
+                                        * Need to follow the parent chain to see if it is hanging.
+                                        */
+                                       hanging = 0;
+                                       depth_limit = 100;
+
+                                       while (parent != dev->root_dir &&
+                                              parent->parent &&
+                                              parent->parent->variant_type ==
+                                              YAFFS_OBJECT_TYPE_DIRECTORY
+                                              && depth_limit > 0) {
+                                               parent = parent->parent;
+                                               depth_limit--;
+                                       }
+                                       if (parent != dev->root_dir)
+                                               hanging = 1;
+                               }
+                               if (hanging) {
+                                       yaffs_trace(YAFFS_TRACE_SCAN,
+                                               "Hanging object %d moved to lost and found",
+                                               obj->obj_id);
+                                       yaffs_add_obj_to_dir(dev->lost_n_found,
+                                                            obj);
+                               }
+                       }
+               }
+       }
+}
+
+/*
+ * Delete directory contents for cleaning up lost and found.
+ */
+static void yaffs_del_dir_contents(struct yaffs_obj *dir)
+{
+       struct yaffs_obj *obj;
+       struct list_head *lh;
+       struct list_head *n;
+
+       if (dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
+               YBUG();
+
+       list_for_each_safe(lh, n, &dir->variant.dir_variant.children) {
+               if (lh) {
+                       obj = list_entry(lh, struct yaffs_obj, siblings);
+                       if (obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY)
+                               yaffs_del_dir_contents(obj);
+
+                       yaffs_trace(YAFFS_TRACE_SCAN,
+                               "Deleting lost_found object %d",
+                               obj->obj_id);
+
+                       /* Need to use UnlinkObject since Delete would not handle
+                        * hardlinked objects correctly.
+                        */
+                       yaffs_unlink_obj(obj);
+               }
+       }
+
+}
+
+static void yaffs_empty_l_n_f(struct yaffs_dev *dev)
+{
+       yaffs_del_dir_contents(dev->lost_n_found);
+}
+
+
+struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *directory,
+                                    const YCHAR * name)
+{
+       int sum;
+
+       struct list_head *i;
+       YCHAR buffer[YAFFS_MAX_NAME_LENGTH + 1];
+
+       struct yaffs_obj *l;
+
+       if (!name)
+               return NULL;
+
+       if (!directory) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "tragedy: yaffs_find_by_name: null pointer directory"
+                       );
+               YBUG();
+               return NULL;
+       }
+       if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "tragedy: yaffs_find_by_name: non-directory"
+                       );
+               YBUG();
+       }
+
+       sum = yaffs_calc_name_sum(name);
+
+       list_for_each(i, &directory->variant.dir_variant.children) {
+               if (i) {
+                       l = list_entry(i, struct yaffs_obj, siblings);
+
+                       if (l->parent != directory)
+                               YBUG();
+
+                       yaffs_check_obj_details_loaded(l);
+
+                       /* Special case for lost-n-found */
+                       if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
+                               if (!strcmp(name, YAFFS_LOSTNFOUND_NAME))
+                                       return l;
+                       } else if (l->sum == sum
+                                  || l->hdr_chunk <= 0) {
+                               /* LostnFound chunk called Objxxx
+                                * Do a real check
+                                */
+                               yaffs_get_obj_name(l, buffer,
+                                                  YAFFS_MAX_NAME_LENGTH + 1);
+                               if (strncmp
+                                   (name, buffer, YAFFS_MAX_NAME_LENGTH) == 0)
+                                       return l;
+                       }
+               }
+       }
+
+       return NULL;
+}
+
+/* GetEquivalentObject dereferences any hard links to get to the
+ * actual object.
+ */
+
+struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj)
+{
+       if (obj && obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
+               /* We want the object id of the equivalent object, not this one */
+               obj = obj->variant.hardlink_variant.equiv_obj;
+               yaffs_check_obj_details_loaded(obj);
+       }
+       return obj;
+}
+
+/*
+ *  A note or two on object names.
+ *  * If the object name is missing, we then make one up in the form objnnn
+ *
+ *  * ASCII names are stored in the object header's name field from byte zero
+ *  * Unicode names are historically stored starting from byte zero.
+ *
+ * Then there are automatic Unicode names...
+ * The purpose of these is to save names in a way that can be read as
+ * ASCII or Unicode names as appropriate, thus allowing a Unicode and ASCII
+ * system to share files.
+ *
+ * These automatic unicode are stored slightly differently...
+ *  - If the name can fit in the ASCII character space then they are saved as 
+ *    ascii names as per above.
+ *  - If the name needs Unicode then the name is saved in Unicode
+ *    starting at oh->name[1].
+
+ */
+static void yaffs_fix_null_name(struct yaffs_obj *obj, YCHAR * name,
+                               int buffer_size)
+{
+       /* Create an object name if we could not find one. */
+       if (strnlen(name, YAFFS_MAX_NAME_LENGTH) == 0) {
+               YCHAR local_name[20];
+               YCHAR num_string[20];
+               YCHAR *x = &num_string[19];
+               unsigned v = obj->obj_id;
+               num_string[19] = 0;
+               while (v > 0) {
+                       x--;
+                       *x = '0' + (v % 10);
+                       v /= 10;
+               }
+               /* make up a name */
+               strcpy(local_name, YAFFS_LOSTNFOUND_PREFIX);
+               strcat(local_name, x);
+               strncpy(name, local_name, buffer_size - 1);
+       }
+}
+
+int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR * name, int buffer_size)
+{
+       memset(name, 0, buffer_size * sizeof(YCHAR));
+
+       yaffs_check_obj_details_loaded(obj);
+
+       if (obj->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
+               strncpy(name, YAFFS_LOSTNFOUND_NAME, buffer_size - 1);
+       }
+#ifndef CONFIG_YAFFS_NO_SHORT_NAMES
+       else if (obj->short_name[0]) {
+               strcpy(name, obj->short_name);
+       }
+#endif
+       else if (obj->hdr_chunk > 0) {
+               int result;
+               u8 *buffer = yaffs_get_temp_buffer(obj->my_dev, __LINE__);
+
+               struct yaffs_obj_hdr *oh = (struct yaffs_obj_hdr *)buffer;
+
+               memset(buffer, 0, obj->my_dev->data_bytes_per_chunk);
+
+               if (obj->hdr_chunk > 0) {
+                       result = yaffs_rd_chunk_tags_nand(obj->my_dev,
+                                                         obj->hdr_chunk,
+                                                         buffer, NULL);
+               }
+               yaffs_load_name_from_oh(obj->my_dev, name, oh->name,
+                                       buffer_size);
+
+               yaffs_release_temp_buffer(obj->my_dev, buffer, __LINE__);
+       }
+
+       yaffs_fix_null_name(obj, name, buffer_size);
+
+       return strnlen(name, YAFFS_MAX_NAME_LENGTH);
+}
+
+int yaffs_get_obj_length(struct yaffs_obj *obj)
+{
+       /* Dereference any hard linking */
+       obj = yaffs_get_equivalent_obj(obj);
+
+       if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
+               return obj->variant.file_variant.file_size;
+       if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
+               if (!obj->variant.symlink_variant.alias)
+                       return 0;
+               return strnlen(obj->variant.symlink_variant.alias,
+                                    YAFFS_MAX_ALIAS_LENGTH);
+       } else {
+               /* Only a directory should drop through to here */
+               return obj->my_dev->data_bytes_per_chunk;
+       }
+}
+
+int yaffs_get_obj_link_count(struct yaffs_obj *obj)
+{
+       int count = 0;
+       struct list_head *i;
+
+       if (!obj->unlinked)
+               count++;        /* the object itself */
+
+       list_for_each(i, &obj->hard_links)
+           count++;            /* add the hard links; */
+
+       return count;
+}
+
+int yaffs_get_obj_inode(struct yaffs_obj *obj)
+{
+       obj = yaffs_get_equivalent_obj(obj);
+
+       return obj->obj_id;
+}
+
+unsigned yaffs_get_obj_type(struct yaffs_obj *obj)
+{
+       obj = yaffs_get_equivalent_obj(obj);
+
+       switch (obj->variant_type) {
+       case YAFFS_OBJECT_TYPE_FILE:
+               return DT_REG;
+               break;
+       case YAFFS_OBJECT_TYPE_DIRECTORY:
+               return DT_DIR;
+               break;
+       case YAFFS_OBJECT_TYPE_SYMLINK:
+               return DT_LNK;
+               break;
+       case YAFFS_OBJECT_TYPE_HARDLINK:
+               return DT_REG;
+               break;
+       case YAFFS_OBJECT_TYPE_SPECIAL:
+               if (S_ISFIFO(obj->yst_mode))
+                       return DT_FIFO;
+               if (S_ISCHR(obj->yst_mode))
+                       return DT_CHR;
+               if (S_ISBLK(obj->yst_mode))
+                       return DT_BLK;
+               if (S_ISSOCK(obj->yst_mode))
+                       return DT_SOCK;
+       default:
+               return DT_REG;
+               break;
+       }
+}
+
+YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj)
+{
+       obj = yaffs_get_equivalent_obj(obj);
+       if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK)
+               return yaffs_clone_str(obj->variant.symlink_variant.alias);
+       else
+               return yaffs_clone_str(_Y(""));
+}
+
+/*--------------------------- Initialisation code -------------------------- */
+
+static int yaffs_check_dev_fns(const struct yaffs_dev *dev)
+{
+
+       /* Common functions, gotta have */
+       if (!dev->param.erase_fn || !dev->param.initialise_flash_fn)
+               return 0;
+
+#ifdef CONFIG_YAFFS_YAFFS2
+
+       /* Can use the "with tags" style interface for yaffs1 or yaffs2 */
+       if (dev->param.write_chunk_tags_fn &&
+           dev->param.read_chunk_tags_fn &&
+           !dev->param.write_chunk_fn &&
+           !dev->param.read_chunk_fn &&
+           dev->param.bad_block_fn && dev->param.query_block_fn)
+               return 1;
+#endif
+
+       /* Can use the "spare" style interface for yaffs1 */
+       if (!dev->param.is_yaffs2 &&
+           !dev->param.write_chunk_tags_fn &&
+           !dev->param.read_chunk_tags_fn &&
+           dev->param.write_chunk_fn &&
+           dev->param.read_chunk_fn &&
+           !dev->param.bad_block_fn && !dev->param.query_block_fn)
+               return 1;
+
+       return 0;               /* bad */
+}
+
+static int yaffs_create_initial_dir(struct yaffs_dev *dev)
+{
+       /* Initialise the unlinked, deleted, root and lost and found directories */
+
+       dev->lost_n_found = dev->root_dir = NULL;
+       dev->unlinked_dir = dev->del_dir = NULL;
+
+       dev->unlinked_dir =
+           yaffs_create_fake_dir(dev, YAFFS_OBJECTID_UNLINKED, S_IFDIR);
+
+       dev->del_dir =
+           yaffs_create_fake_dir(dev, YAFFS_OBJECTID_DELETED, S_IFDIR);
+
+       dev->root_dir =
+           yaffs_create_fake_dir(dev, YAFFS_OBJECTID_ROOT,
+                                 YAFFS_ROOT_MODE | S_IFDIR);
+       dev->lost_n_found =
+           yaffs_create_fake_dir(dev, YAFFS_OBJECTID_LOSTNFOUND,
+                                 YAFFS_LOSTNFOUND_MODE | S_IFDIR);
+
+       if (dev->lost_n_found && dev->root_dir && dev->unlinked_dir
+           && dev->del_dir) {
+               yaffs_add_obj_to_dir(dev->root_dir, dev->lost_n_found);
+               return YAFFS_OK;
+       }
+
+       return YAFFS_FAIL;
+}
+
+int yaffs_guts_initialise(struct yaffs_dev *dev)
+{
+       int init_failed = 0;
+       unsigned x;
+       int bits;
+
+       yaffs_trace(YAFFS_TRACE_TRACING, "yaffs: yaffs_guts_initialise()" );
+
+       /* Check stuff that must be set */
+
+       if (!dev) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "yaffs: Need a device"
+                       );
+               return YAFFS_FAIL;
+       }
+
+       dev->internal_start_block = dev->param.start_block;
+       dev->internal_end_block = dev->param.end_block;
+       dev->block_offset = 0;
+       dev->chunk_offset = 0;
+       dev->n_free_chunks = 0;
+
+       dev->gc_block = 0;
+
+       if (dev->param.start_block == 0) {
+               dev->internal_start_block = dev->param.start_block + 1;
+               dev->internal_end_block = dev->param.end_block + 1;
+               dev->block_offset = 1;
+               dev->chunk_offset = dev->param.chunks_per_block;
+       }
+
+       /* Check geometry parameters. */
+
+       if ((!dev->param.inband_tags && dev->param.is_yaffs2 &&
+               dev->param.total_bytes_per_chunk < 1024) ||
+               (!dev->param.is_yaffs2 &&
+                       dev->param.total_bytes_per_chunk < 512) ||
+               (dev->param.inband_tags && !dev->param.is_yaffs2) ||
+                dev->param.chunks_per_block < 2 ||
+                dev->param.n_reserved_blocks < 2 ||
+               dev->internal_start_block <= 0 || 
+               dev->internal_end_block <= 0 || 
+               dev->internal_end_block <= 
+               (dev->internal_start_block + dev->param.n_reserved_blocks + 2)
+               ) {
+               /* otherwise it is too small */
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "NAND geometry problems: chunk size %d, type is yaffs%s, inband_tags %d ",
+                       dev->param.total_bytes_per_chunk,
+                       dev->param.is_yaffs2 ? "2" : "",
+                       dev->param.inband_tags);
+               return YAFFS_FAIL;
+       }
+
+       if (yaffs_init_nand(dev) != YAFFS_OK) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS, "InitialiseNAND failed");
+               return YAFFS_FAIL;
+       }
+
+       /* Sort out space for inband tags, if required */
+       if (dev->param.inband_tags)
+               dev->data_bytes_per_chunk =
+                   dev->param.total_bytes_per_chunk -
+                   sizeof(struct yaffs_packed_tags2_tags_only);
+       else
+               dev->data_bytes_per_chunk = dev->param.total_bytes_per_chunk;
+
+       /* Got the right mix of functions? */
+       if (!yaffs_check_dev_fns(dev)) {
+               /* Function missing */
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "device function(s) missing or wrong");
+
+               return YAFFS_FAIL;
+       }
+
+       if (dev->is_mounted) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS, "device already mounted");
+               return YAFFS_FAIL;
+       }
+
+       /* Finished with most checks. One or two more checks happen later on too. */
+
+       dev->is_mounted = 1;
+
+       /* OK now calculate a few things for the device */
+
+       /*
+        *  Calculate all the chunk size manipulation numbers:
+        */
+       x = dev->data_bytes_per_chunk;
+       /* We always use dev->chunk_shift and dev->chunk_div */
+       dev->chunk_shift = calc_shifts(x);
+       x >>= dev->chunk_shift;
+       dev->chunk_div = x;
+       /* We only use chunk mask if chunk_div is 1 */
+       dev->chunk_mask = (1 << dev->chunk_shift) - 1;
+
+       /*
+        * Calculate chunk_grp_bits.
+        * We need to find the next power of 2 > than internal_end_block
+        */
+
+       x = dev->param.chunks_per_block * (dev->internal_end_block + 1);
+
+       bits = calc_shifts_ceiling(x);
+
+       /* Set up tnode width if wide tnodes are enabled. */
+       if (!dev->param.wide_tnodes_disabled) {
+               /* bits must be even so that we end up with 32-bit words */
+               if (bits & 1)
+                       bits++;
+               if (bits < 16)
+                       dev->tnode_width = 16;
+               else
+                       dev->tnode_width = bits;
+       } else {
+               dev->tnode_width = 16;
+        }
+
+       dev->tnode_mask = (1 << dev->tnode_width) - 1;
+
+       /* Level0 Tnodes are 16 bits or wider (if wide tnodes are enabled),
+        * so if the bitwidth of the
+        * chunk range we're using is greater than 16 we need
+        * to figure out chunk shift and chunk_grp_size
+        */
+
+       if (bits <= dev->tnode_width)
+               dev->chunk_grp_bits = 0;
+       else
+               dev->chunk_grp_bits = bits - dev->tnode_width;
+
+       dev->tnode_size = (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8;
+       if (dev->tnode_size < sizeof(struct yaffs_tnode))
+               dev->tnode_size = sizeof(struct yaffs_tnode);
+
+       dev->chunk_grp_size = 1 << dev->chunk_grp_bits;
+
+       if (dev->param.chunks_per_block < dev->chunk_grp_size) {
+               /* We have a problem because the soft delete won't work if
+                * the chunk group size > chunks per block.
+                * This can be remedied by using larger "virtual blocks".
+                */
+               yaffs_trace(YAFFS_TRACE_ALWAYS, "chunk group too large");
+
+               return YAFFS_FAIL;
+       }
+
+       /* OK, we've finished verifying the device, lets continue with initialisation */
+
+       /* More device initialisation */
+       dev->all_gcs = 0;
+       dev->passive_gc_count = 0;
+       dev->oldest_dirty_gc_count = 0;
+       dev->bg_gcs = 0;
+       dev->gc_block_finder = 0;
+       dev->buffered_block = -1;
+       dev->doing_buffered_block_rewrite = 0;
+       dev->n_deleted_files = 0;
+       dev->n_bg_deletions = 0;
+       dev->n_unlinked_files = 0;
+       dev->n_ecc_fixed = 0;
+       dev->n_ecc_unfixed = 0;
+       dev->n_tags_ecc_fixed = 0;
+       dev->n_tags_ecc_unfixed = 0;
+       dev->n_erase_failures = 0;
+       dev->n_erased_blocks = 0;
+       dev->gc_disable = 0;
+       dev->has_pending_prioritised_gc = 1;    /* Assume the worst for now, will get fixed on first GC */
+       INIT_LIST_HEAD(&dev->dirty_dirs);
+       dev->oldest_dirty_seq = 0;
+       dev->oldest_dirty_block = 0;
+
+       /* Initialise temporary buffers and caches. */
+       if (!yaffs_init_tmp_buffers(dev))
+               init_failed = 1;
+
+       dev->cache = NULL;
+       dev->gc_cleanup_list = NULL;
+
+       if (!init_failed && dev->param.n_caches > 0) {
+               int i;
+               void *buf;
+               int cache_bytes =
+                   dev->param.n_caches * sizeof(struct yaffs_cache);
+
+               if (dev->param.n_caches > YAFFS_MAX_SHORT_OP_CACHES)
+                       dev->param.n_caches = YAFFS_MAX_SHORT_OP_CACHES;
+
+               dev->cache = kmalloc(cache_bytes, GFP_NOFS);
+
+               buf = (u8 *) dev->cache;
+
+               if (dev->cache)
+                       memset(dev->cache, 0, cache_bytes);
+
+               for (i = 0; i < dev->param.n_caches && buf; i++) {
+                       dev->cache[i].object = NULL;
+                       dev->cache[i].last_use = 0;
+                       dev->cache[i].dirty = 0;
+                       dev->cache[i].data = buf =
+                           kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
+               }
+               if (!buf)
+                       init_failed = 1;
+
+               dev->cache_last_use = 0;
+       }
+
+       dev->cache_hits = 0;
+
+       if (!init_failed) {
+               dev->gc_cleanup_list =
+                   kmalloc(dev->param.chunks_per_block * sizeof(u32),
+                                       GFP_NOFS);
+               if (!dev->gc_cleanup_list)
+                       init_failed = 1;
+       }
+
+       if (dev->param.is_yaffs2)
+               dev->param.use_header_file_size = 1;
+
+       if (!init_failed && !yaffs_init_blocks(dev))
+               init_failed = 1;
+
+       yaffs_init_tnodes_and_objs(dev);
+
+       if (!init_failed && !yaffs_create_initial_dir(dev))
+               init_failed = 1;
+
+       if (!init_failed) {
+               /* Now scan the flash. */
+               if (dev->param.is_yaffs2) {
+                       if (yaffs2_checkpt_restore(dev)) {
+                               yaffs_check_obj_details_loaded(dev->root_dir);
+                               yaffs_trace(YAFFS_TRACE_CHECKPOINT | YAFFS_TRACE_MOUNT,
+                                       "yaffs: restored from checkpoint"
+                                       );
+                       } else {
+
+                               /* Clean up the mess caused by an aborted checkpoint load
+                                * and scan backwards.
+                                */
+                               yaffs_deinit_blocks(dev);
+
+                               yaffs_deinit_tnodes_and_objs(dev);
+
+                               dev->n_erased_blocks = 0;
+                               dev->n_free_chunks = 0;
+                               dev->alloc_block = -1;
+                               dev->alloc_page = -1;
+                               dev->n_deleted_files = 0;
+                               dev->n_unlinked_files = 0;
+                               dev->n_bg_deletions = 0;
+
+                               if (!init_failed && !yaffs_init_blocks(dev))
+                                       init_failed = 1;
+
+                               yaffs_init_tnodes_and_objs(dev);
+
+                               if (!init_failed
+                                   && !yaffs_create_initial_dir(dev))
+                                       init_failed = 1;
+
+                               if (!init_failed && !yaffs2_scan_backwards(dev))
+                                       init_failed = 1;
+                       }
+               } else if (!yaffs1_scan(dev)) {
+                       init_failed = 1;
+                }
+
+               yaffs_strip_deleted_objs(dev);
+               yaffs_fix_hanging_objs(dev);
+               if (dev->param.empty_lost_n_found)
+                       yaffs_empty_l_n_f(dev);
+       }
+
+       if (init_failed) {
+               /* Clean up the mess */
+               yaffs_trace(YAFFS_TRACE_TRACING,
+                 "yaffs: yaffs_guts_initialise() aborted.");
+
+               yaffs_deinitialise(dev);
+               return YAFFS_FAIL;
+       }
+
+       /* Zero out stats */
+       dev->n_page_reads = 0;
+       dev->n_page_writes = 0;
+       dev->n_erasures = 0;
+       dev->n_gc_copies = 0;
+       dev->n_retired_writes = 0;
+
+       dev->n_retired_blocks = 0;
+
+       yaffs_verify_free_chunks(dev);
+       yaffs_verify_blocks(dev);
+
+       /* Clean up any aborted checkpoint data */
+       if (!dev->is_checkpointed && dev->blocks_in_checkpt > 0)
+               yaffs2_checkpt_invalidate(dev);
+
+       yaffs_trace(YAFFS_TRACE_TRACING,
+         "yaffs: yaffs_guts_initialise() done.");
+       return YAFFS_OK;
+
+}
+
+void yaffs_deinitialise(struct yaffs_dev *dev)
+{
+       if (dev->is_mounted) {
+               int i;
+
+               yaffs_deinit_blocks(dev);
+               yaffs_deinit_tnodes_and_objs(dev);
+               if (dev->param.n_caches > 0 && dev->cache) {
+
+                       for (i = 0; i < dev->param.n_caches; i++) {
+                               if (dev->cache[i].data)
+                                       kfree(dev->cache[i].data);
+                               dev->cache[i].data = NULL;
+                       }
+
+                       kfree(dev->cache);
+                       dev->cache = NULL;
+               }
+
+               kfree(dev->gc_cleanup_list);
+
+               for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
+                       kfree(dev->temp_buffer[i].buffer);
+
+               dev->is_mounted = 0;
+
+               if (dev->param.deinitialise_flash_fn)
+                       dev->param.deinitialise_flash_fn(dev);
+       }
+}
+
+int yaffs_count_free_chunks(struct yaffs_dev *dev)
+{
+       int n_free = 0;
+       int b;
+
+       struct yaffs_block_info *blk;
+
+       blk = dev->block_info;
+       for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
+               switch (blk->block_state) {
+               case YAFFS_BLOCK_STATE_EMPTY:
+               case YAFFS_BLOCK_STATE_ALLOCATING:
+               case YAFFS_BLOCK_STATE_COLLECTING:
+               case YAFFS_BLOCK_STATE_FULL:
+                       n_free +=
+                           (dev->param.chunks_per_block - blk->pages_in_use +
+                            blk->soft_del_pages);
+                       break;
+               default:
+                       break;
+               }
+               blk++;
+       }
+
+       return n_free;
+}
+
+int yaffs_get_n_free_chunks(struct yaffs_dev *dev)
+{
+       /* This is what we report to the outside world */
+
+       int n_free;
+       int n_dirty_caches;
+       int blocks_for_checkpt;
+       int i;
+
+       n_free = dev->n_free_chunks;
+       n_free += dev->n_deleted_files;
+
+       /* Now count the number of dirty chunks in the cache and subtract those */
+
+       for (n_dirty_caches = 0, i = 0; i < dev->param.n_caches; i++) {
+               if (dev->cache[i].dirty)
+                       n_dirty_caches++;
+       }
+
+       n_free -= n_dirty_caches;
+
+       n_free -=
+           ((dev->param.n_reserved_blocks + 1) * dev->param.chunks_per_block);
+
+       /* Now we figure out how much to reserve for the checkpoint and report that... */
+       blocks_for_checkpt = yaffs_calc_checkpt_blocks_required(dev);
+
+       n_free -= (blocks_for_checkpt * dev->param.chunks_per_block);
+
+       if (n_free < 0)
+               n_free = 0;
+
+       return n_free;
+
+}
diff --git a/fs/yaffs2/yaffs_guts.h b/fs/yaffs2/yaffs_guts.h
new file mode 100644 (file)
index 0000000..307eba2
--- /dev/null
@@ -0,0 +1,915 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_GUTS_H__
+#define __YAFFS_GUTS_H__
+
+#include "yportenv.h"
+
+#define YAFFS_OK       1
+#define YAFFS_FAIL  0
+
+/* Give us a  Y=0x59,
+ * Give us an A=0x41,
+ * Give us an FF=0xFF
+ * Give us an S=0x53
+ * And what have we got...
+ */
+#define YAFFS_MAGIC                    0x5941FF53
+
+#define YAFFS_NTNODES_LEVEL0           16
+#define YAFFS_TNODES_LEVEL0_BITS       4
+#define YAFFS_TNODES_LEVEL0_MASK       0xf
+
+#define YAFFS_NTNODES_INTERNAL                 (YAFFS_NTNODES_LEVEL0 / 2)
+#define YAFFS_TNODES_INTERNAL_BITS     (YAFFS_TNODES_LEVEL0_BITS - 1)
+#define YAFFS_TNODES_INTERNAL_MASK     0x7
+#define YAFFS_TNODES_MAX_LEVEL         6
+
+#ifndef CONFIG_YAFFS_NO_YAFFS1
+#define YAFFS_BYTES_PER_SPARE          16
+#define YAFFS_BYTES_PER_CHUNK          512
+#define YAFFS_CHUNK_SIZE_SHIFT         9
+#define YAFFS_CHUNKS_PER_BLOCK         32
+#define YAFFS_BYTES_PER_BLOCK          (YAFFS_CHUNKS_PER_BLOCK*YAFFS_BYTES_PER_CHUNK)
+#endif
+
+#define YAFFS_MIN_YAFFS2_CHUNK_SIZE    1024
+#define YAFFS_MIN_YAFFS2_SPARE_SIZE    32
+
+#define YAFFS_MAX_CHUNK_ID             0x000FFFFF
+
+#define YAFFS_ALLOCATION_NOBJECTS      100
+#define YAFFS_ALLOCATION_NTNODES       100
+#define YAFFS_ALLOCATION_NLINKS                100
+
+#define YAFFS_NOBJECT_BUCKETS          256
+
+#define YAFFS_OBJECT_SPACE             0x40000
+#define YAFFS_MAX_OBJECT_ID            (YAFFS_OBJECT_SPACE -1)
+
+#define YAFFS_CHECKPOINT_VERSION       4
+
+#ifdef CONFIG_YAFFS_UNICODE
+#define YAFFS_MAX_NAME_LENGTH          127
+#define YAFFS_MAX_ALIAS_LENGTH         79
+#else
+#define YAFFS_MAX_NAME_LENGTH          255
+#define YAFFS_MAX_ALIAS_LENGTH         159
+#endif
+
+#define YAFFS_SHORT_NAME_LENGTH                15
+
+/* Some special object ids for pseudo objects */
+#define YAFFS_OBJECTID_ROOT            1
+#define YAFFS_OBJECTID_LOSTNFOUND      2
+#define YAFFS_OBJECTID_UNLINKED                3
+#define YAFFS_OBJECTID_DELETED         4
+
+/* Pseudo object ids for checkpointing */
+#define YAFFS_OBJECTID_SB_HEADER       0x10
+#define YAFFS_OBJECTID_CHECKPOINT_DATA 0x20
+#define YAFFS_SEQUENCE_CHECKPOINT_DATA  0x21
+
+#define YAFFS_MAX_SHORT_OP_CACHES      20
+
+#define YAFFS_N_TEMP_BUFFERS           6
+
+/* We limit the number attempts at sucessfully saving a chunk of data.
+ * Small-page devices have 32 pages per block; large-page devices have 64.
+ * Default to something in the order of 5 to 10 blocks worth of chunks.
+ */
+#define YAFFS_WR_ATTEMPTS              (5*64)
+
+/* Sequence numbers are used in YAFFS2 to determine block allocation order.
+ * The range is limited slightly to help distinguish bad numbers from good.
+ * This also allows us to perhaps in the future use special numbers for
+ * special purposes.
+ * EFFFFF00 allows the allocation of 8 blocks per second (~1Mbytes) for 15 years,
+ * and is a larger number than the lifetime of a 2GB device.
+ */
+#define YAFFS_LOWEST_SEQUENCE_NUMBER   0x00001000
+#define YAFFS_HIGHEST_SEQUENCE_NUMBER  0xEFFFFF00
+
+/* Special sequence number for bad block that failed to be marked bad */
+#define YAFFS_SEQUENCE_BAD_BLOCK       0xFFFF0000
+
+/* ChunkCache is used for short read/write operations.*/
+struct yaffs_cache {
+       struct yaffs_obj *object;
+       int chunk_id;
+       int last_use;
+       int dirty;
+       int n_bytes;            /* Only valid if the cache is dirty */
+       int locked;             /* Can't push out or flush while locked. */
+       u8 *data;
+};
+
+/* Tags structures in RAM
+ * NB This uses bitfield. Bitfields should not straddle a u32 boundary otherwise
+ * the structure size will get blown out.
+ */
+
+#ifndef CONFIG_YAFFS_NO_YAFFS1
+struct yaffs_tags {
+       unsigned chunk_id:20;
+       unsigned serial_number:2;
+       unsigned n_bytes_lsb:10;
+       unsigned obj_id:18;
+       unsigned ecc:12;
+       unsigned n_bytes_msb:2;
+};
+
+union yaffs_tags_union {
+       struct yaffs_tags as_tags;
+       u8 as_bytes[8];
+};
+
+#endif
+
+/* Stuff used for extended tags in YAFFS2 */
+
+enum yaffs_ecc_result {
+       YAFFS_ECC_RESULT_UNKNOWN,
+       YAFFS_ECC_RESULT_NO_ERROR,
+       YAFFS_ECC_RESULT_FIXED,
+       YAFFS_ECC_RESULT_UNFIXED
+};
+
+enum yaffs_obj_type {
+       YAFFS_OBJECT_TYPE_UNKNOWN,
+       YAFFS_OBJECT_TYPE_FILE,
+       YAFFS_OBJECT_TYPE_SYMLINK,
+       YAFFS_OBJECT_TYPE_DIRECTORY,
+       YAFFS_OBJECT_TYPE_HARDLINK,
+       YAFFS_OBJECT_TYPE_SPECIAL
+};
+
+#define YAFFS_OBJECT_TYPE_MAX YAFFS_OBJECT_TYPE_SPECIAL
+
+struct yaffs_ext_tags {
+
+       unsigned validity0;
+       unsigned chunk_used;    /*  Status of the chunk: used or unused */
+       unsigned obj_id;        /* If 0 then this is not part of an object (unused) */
+       unsigned chunk_id;      /* If 0 then this is a header, else a data chunk */
+       unsigned n_bytes;       /* Only valid for data chunks */
+
+       /* The following stuff only has meaning when we read */
+       enum yaffs_ecc_result ecc_result;
+       unsigned block_bad;
+
+       /* YAFFS 1 stuff */
+       unsigned is_deleted;    /* The chunk is marked deleted */
+       unsigned serial_number; /* Yaffs1 2-bit serial number */
+
+       /* YAFFS2 stuff */
+       unsigned seq_number;    /* The sequence number of this block */
+
+       /* Extra info if this is an object header (YAFFS2 only) */
+
+       unsigned extra_available;       /* There is extra info available if this is not zero */
+       unsigned extra_parent_id;       /* The parent object */
+       unsigned extra_is_shrink;       /* Is it a shrink header? */
+       unsigned extra_shadows; /* Does this shadow another object? */
+
+       enum yaffs_obj_type extra_obj_type;     /* What object type? */
+
+       unsigned extra_length;  /* Length if it is a file */
+       unsigned extra_equiv_id;        /* Equivalent object Id if it is a hard link */
+
+       unsigned validity1;
+
+};
+
+/* Spare structure for YAFFS1 */
+struct yaffs_spare {
+       u8 tb0;
+       u8 tb1;
+       u8 tb2;
+       u8 tb3;
+       u8 page_status;         /* set to 0 to delete the chunk */
+       u8 block_status;
+       u8 tb4;
+       u8 tb5;
+       u8 ecc1[3];
+       u8 tb6;
+       u8 tb7;
+       u8 ecc2[3];
+};
+
+/*Special structure for passing through to mtd */
+struct yaffs_nand_spare {
+       struct yaffs_spare spare;
+       int eccres1;
+       int eccres2;
+};
+
+/* Block data in RAM */
+
+enum yaffs_block_state {
+       YAFFS_BLOCK_STATE_UNKNOWN = 0,
+
+       YAFFS_BLOCK_STATE_SCANNING,
+       /* Being scanned */
+
+       YAFFS_BLOCK_STATE_NEEDS_SCANNING,
+       /* The block might have something on it (ie it is allocating or full, perhaps empty)
+        * but it needs to be scanned to determine its true state.
+        * This state is only valid during scanning.
+        * NB We tolerate empty because the pre-scanner might be incapable of deciding
+        * However, if this state is returned on a YAFFS2 device, then we expect a sequence number
+        */
+
+       YAFFS_BLOCK_STATE_EMPTY,
+       /* This block is empty */
+
+       YAFFS_BLOCK_STATE_ALLOCATING,
+       /* This block is partially allocated.
+        * At least one page holds valid data.
+        * This is the one currently being used for page
+        * allocation. Should never be more than one of these.
+        * If a block is only partially allocated at mount it is treated as full.
+        */
+
+       YAFFS_BLOCK_STATE_FULL,
+       /* All the pages in this block have been allocated.
+        * If a block was only partially allocated when mounted we treat
+        * it as fully allocated.
+        */
+
+       YAFFS_BLOCK_STATE_DIRTY,
+       /* The block was full and now all chunks have been deleted.
+        * Erase me, reuse me.
+        */
+
+       YAFFS_BLOCK_STATE_CHECKPOINT,
+       /* This block is assigned to holding checkpoint data. */
+
+       YAFFS_BLOCK_STATE_COLLECTING,
+       /* This block is being garbage collected */
+
+       YAFFS_BLOCK_STATE_DEAD
+           /* This block has failed and is not in use */
+};
+
+#define        YAFFS_NUMBER_OF_BLOCK_STATES (YAFFS_BLOCK_STATE_DEAD + 1)
+
+struct yaffs_block_info {
+
+       int soft_del_pages:10;  /* number of soft deleted pages */
+       int pages_in_use:10;    /* number of pages in use */
+       unsigned block_state:4; /* One of the above block states. NB use unsigned because enum is sometimes an int */
+       u32 needs_retiring:1;   /* Data has failed on this block, need to get valid data off */
+       /* and retire the block. */
+       u32 skip_erased_check:1;        /* If this is set we can skip the erased check on this block */
+       u32 gc_prioritise:1;    /* An ECC check or blank check has failed on this block.
+                                  It should be prioritised for GC */
+       u32 chunk_error_strikes:3;      /* How many times we've had ecc etc failures on this block and tried to reuse it */
+
+#ifdef CONFIG_YAFFS_YAFFS2
+       u32 has_shrink_hdr:1;   /* This block has at least one shrink object header */
+       u32 seq_number;         /* block sequence number for yaffs2 */
+#endif
+
+};
+
+/* -------------------------- Object structure -------------------------------*/
+/* This is the object structure as stored on NAND */
+
+struct yaffs_obj_hdr {
+       enum yaffs_obj_type type;
+
+       /* Apply to everything  */
+       int parent_obj_id;
+       u16 sum_no_longer_used; /* checksum of name. No longer used */
+       YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
+
+       /* The following apply to directories, files, symlinks - not hard links */
+       u32 yst_mode;           /* protection */
+
+       u32 yst_uid;
+       u32 yst_gid;
+       u32 yst_atime;
+       u32 yst_mtime;
+       u32 yst_ctime;
+
+       /* File size  applies to files only */
+       int file_size;
+
+       /* Equivalent object id applies to hard links only. */
+       int equiv_id;
+
+       /* Alias is for symlinks only. */
+       YCHAR alias[YAFFS_MAX_ALIAS_LENGTH + 1];
+
+       u32 yst_rdev;           /* device stuff for block and char devices (major/min) */
+
+       u32 win_ctime[2];
+       u32 win_atime[2];
+       u32 win_mtime[2];
+
+       u32 inband_shadowed_obj_id;
+       u32 inband_is_shrink;
+
+       u32 reserved[2];
+       int shadows_obj;        /* This object header shadows the specified object if > 0 */
+
+       /* is_shrink applies to object headers written when we shrink the file (ie resize) */
+       u32 is_shrink;
+
+};
+
+/*--------------------------- Tnode -------------------------- */
+
+struct yaffs_tnode {
+       struct yaffs_tnode *internal[YAFFS_NTNODES_INTERNAL];
+};
+
+/*------------------------  Object -----------------------------*/
+/* An object can be one of:
+ * - a directory (no data, has children links
+ * - a regular file (data.... not prunes :->).
+ * - a symlink [symbolic link] (the alias).
+ * - a hard link
+ */
+
+struct yaffs_file_var {
+       u32 file_size;
+       u32 scanned_size;
+       u32 shrink_size;
+       int top_level;
+       struct yaffs_tnode *top;
+};
+
+struct yaffs_dir_var {
+       struct list_head children;      /* list of child links */
+       struct list_head dirty; /* Entry for list of dirty directories */
+};
+
+struct yaffs_symlink_var {
+       YCHAR *alias;
+};
+
+struct yaffs_hardlink_var {
+       struct yaffs_obj *equiv_obj;
+       u32 equiv_id;
+};
+
+union yaffs_obj_var {
+       struct yaffs_file_var file_variant;
+       struct yaffs_dir_var dir_variant;
+       struct yaffs_symlink_var symlink_variant;
+       struct yaffs_hardlink_var hardlink_variant;
+};
+
+struct yaffs_obj {
+       u8 deleted:1;           /* This should only apply to unlinked files. */
+       u8 soft_del:1;          /* it has also been soft deleted */
+       u8 unlinked:1;          /* An unlinked file. The file should be in the unlinked directory. */
+       u8 fake:1;              /* A fake object has no presence on NAND. */
+       u8 rename_allowed:1;    /* Some objects are not allowed to be renamed. */
+       u8 unlink_allowed:1;
+       u8 dirty:1;             /* the object needs to be written to flash */
+       u8 valid:1;             /* When the file system is being loaded up, this
+                                * object might be created before the data
+                                * is available (ie. file data records appear before the header).
+                                */
+       u8 lazy_loaded:1;       /* This object has been lazy loaded and is missing some detail */
+
+       u8 defered_free:1;      /* For Linux kernel. Object is removed from NAND, but is
+                                * still in the inode cache. Free of object is defered.
+                                * until the inode is released.
+                                */
+       u8 being_created:1;     /* This object is still being created so skip some checks. */
+       u8 is_shadowed:1;       /* This object is shadowed on the way to being renamed. */
+
+       u8 xattr_known:1;       /* We know if this has object has xattribs or not. */
+       u8 has_xattr:1;         /* This object has xattribs. Valid if xattr_known. */
+
+       u8 serial;              /* serial number of chunk in NAND. Cached here */
+       u16 sum;                /* sum of the name to speed searching */
+
+       struct yaffs_dev *my_dev;       /* The device I'm on */
+
+       struct list_head hash_link;     /* list of objects in this hash bucket */
+
+       struct list_head hard_links;    /* all the equivalent hard linked objects */
+
+       /* directory structure stuff */
+       /* also used for linking up the free list */
+       struct yaffs_obj *parent;
+       struct list_head siblings;
+
+       /* Where's my object header in NAND? */
+       int hdr_chunk;
+
+       int n_data_chunks;      /* Number of data chunks attached to the file. */
+
+       u32 obj_id;             /* the object id value */
+
+       u32 yst_mode;
+
+#ifndef CONFIG_YAFFS_NO_SHORT_NAMES
+       YCHAR short_name[YAFFS_SHORT_NAME_LENGTH + 1];
+#endif
+
+#ifdef CONFIG_YAFFS_WINCE
+       u32 win_ctime[2];
+       u32 win_mtime[2];
+       u32 win_atime[2];
+#else
+       u32 yst_uid;
+       u32 yst_gid;
+       u32 yst_atime;
+       u32 yst_mtime;
+       u32 yst_ctime;
+#endif
+
+       u32 yst_rdev;
+
+       void *my_inode;
+
+       enum yaffs_obj_type variant_type;
+
+       union yaffs_obj_var variant;
+
+};
+
+struct yaffs_obj_bucket {
+       struct list_head list;
+       int count;
+};
+
+/* yaffs_checkpt_obj holds the definition of an object as dumped
+ * by checkpointing.
+ */
+
+struct yaffs_checkpt_obj {
+       int struct_type;
+       u32 obj_id;
+       u32 parent_id;
+       int hdr_chunk;
+       enum yaffs_obj_type variant_type:3;
+       u8 deleted:1;
+       u8 soft_del:1;
+       u8 unlinked:1;
+       u8 fake:1;
+       u8 rename_allowed:1;
+       u8 unlink_allowed:1;
+       u8 serial;
+       int n_data_chunks;
+       u32 size_or_equiv_obj;
+};
+
+/*--------------------- Temporary buffers ----------------
+ *
+ * These are chunk-sized working buffers. Each device has a few
+ */
+
+struct yaffs_buffer {
+       u8 *buffer;
+       int line;               /* track from whence this buffer was allocated */
+       int max_line;
+};
+
+/*----------------- Device ---------------------------------*/
+
+struct yaffs_param {
+       const YCHAR *name;
+
+       /*
+        * Entry parameters set up way early. Yaffs sets up the rest.
+        * The structure should be zeroed out before use so that unused
+        * and defualt values are zero.
+        */
+
+       int inband_tags;        /* Use unband tags */
+       u32 total_bytes_per_chunk;      /* Should be >= 512, does not need to be a power of 2 */
+       int chunks_per_block;   /* does not need to be a power of 2 */
+       int spare_bytes_per_chunk;      /* spare area size */
+       int start_block;        /* Start block we're allowed to use */
+       int end_block;          /* End block we're allowed to use */
+       int n_reserved_blocks;  /* We want this tuneable so that we can reduce */
+       /* reserved blocks on NOR and RAM. */
+
+       int n_caches;           /* If <= 0, then short op caching is disabled, else
+                                * the number of short op caches (don't use too many).
+                                * 10 to 20 is a good bet.
+                                */
+       int use_nand_ecc;       /* Flag to decide whether or not to use NANDECC on data (yaffs1) */
+       int no_tags_ecc;        /* Flag to decide whether or not to do ECC on packed tags (yaffs2) */
+
+       int is_yaffs2;          /* Use yaffs2 mode on this device */
+
+       int empty_lost_n_found; /* Auto-empty lost+found directory on mount */
+
+       int refresh_period;     /* How often we should check to do a block refresh */
+
+       /* Checkpoint control. Can be set before or after initialisation */
+       u8 skip_checkpt_rd;
+       u8 skip_checkpt_wr;
+
+       int enable_xattr;       /* Enable xattribs */
+
+       /* NAND access functions (Must be set before calling YAFFS) */
+
+       int (*write_chunk_fn) (struct yaffs_dev * dev,
+                              int nand_chunk, const u8 * data,
+                              const struct yaffs_spare * spare);
+       int (*read_chunk_fn) (struct yaffs_dev * dev,
+                             int nand_chunk, u8 * data,
+                             struct yaffs_spare * spare);
+       int (*erase_fn) (struct yaffs_dev * dev, int flash_block);
+       int (*initialise_flash_fn) (struct yaffs_dev * dev);
+       int (*deinitialise_flash_fn) (struct yaffs_dev * dev);
+
+#ifdef CONFIG_YAFFS_YAFFS2
+       int (*write_chunk_tags_fn) (struct yaffs_dev * dev,
+                                   int nand_chunk, const u8 * data,
+                                   const struct yaffs_ext_tags * tags);
+       int (*read_chunk_tags_fn) (struct yaffs_dev * dev,
+                                  int nand_chunk, u8 * data,
+                                  struct yaffs_ext_tags * tags);
+       int (*bad_block_fn) (struct yaffs_dev * dev, int block_no);
+       int (*query_block_fn) (struct yaffs_dev * dev, int block_no,
+                              enum yaffs_block_state * state,
+                              u32 * seq_number);
+#endif
+
+       /* The remove_obj_fn function must be supplied by OS flavours that
+        * need it.
+        * yaffs direct uses it to implement the faster readdir.
+        * Linux uses it to protect the directory during unlocking.
+        */
+       void (*remove_obj_fn) (struct yaffs_obj * obj);
+
+       /* Callback to mark the superblock dirty */
+       void (*sb_dirty_fn) (struct yaffs_dev * dev);
+
+       /*  Callback to control garbage collection. */
+       unsigned (*gc_control) (struct yaffs_dev * dev);
+
+       /* Debug control flags. Don't use unless you know what you're doing */
+       int use_header_file_size;       /* Flag to determine if we should use file sizes from the header */
+       int disable_lazy_load;  /* Disable lazy loading on this device */
+       int wide_tnodes_disabled;       /* Set to disable wide tnodes */
+       int disable_soft_del;   /* yaffs 1 only: Set to disable the use of softdeletion. */
+
+       int defered_dir_update; /* Set to defer directory updates */
+
+#ifdef CONFIG_YAFFS_AUTO_UNICODE
+       int auto_unicode;
+#endif
+       int always_check_erased;        /* Force chunk erased check always on */
+};
+
+struct yaffs_dev {
+       struct yaffs_param param;
+
+       /* Context storage. Holds extra OS specific data for this device */
+
+       void *os_context;
+       void *driver_context;
+
+       struct list_head dev_list;
+
+       /* Runtime parameters. Set up by YAFFS. */
+       int data_bytes_per_chunk;
+
+       /* Non-wide tnode stuff */
+       u16 chunk_grp_bits;     /* Number of bits that need to be resolved if
+                                * the tnodes are not wide enough.
+                                */
+       u16 chunk_grp_size;     /* == 2^^chunk_grp_bits */
+
+       /* Stuff to support wide tnodes */
+       u32 tnode_width;
+       u32 tnode_mask;
+       u32 tnode_size;
+
+       /* Stuff for figuring out file offset to chunk conversions */
+       u32 chunk_shift;        /* Shift value */
+       u32 chunk_div;          /* Divisor after shifting: 1 for power-of-2 sizes */
+       u32 chunk_mask;         /* Mask to use for power-of-2 case */
+
+       int is_mounted;
+       int read_only;
+       int is_checkpointed;
+
+       /* Stuff to support block offsetting to support start block zero */
+       int internal_start_block;
+       int internal_end_block;
+       int block_offset;
+       int chunk_offset;
+
+       /* Runtime checkpointing stuff */
+       int checkpt_page_seq;   /* running sequence number of checkpoint pages */
+       int checkpt_byte_count;
+       int checkpt_byte_offs;
+       u8 *checkpt_buffer;
+       int checkpt_open_write;
+       int blocks_in_checkpt;
+       int checkpt_cur_chunk;
+       int checkpt_cur_block;
+       int checkpt_next_block;
+       int *checkpt_block_list;
+       int checkpt_max_blocks;
+       u32 checkpt_sum;
+       u32 checkpt_xor;
+
+       int checkpoint_blocks_required; /* Number of blocks needed to store current checkpoint set */
+
+       /* Block Info */
+       struct yaffs_block_info *block_info;
+       u8 *chunk_bits;         /* bitmap of chunks in use */
+       unsigned block_info_alt:1;      /* was allocated using alternative strategy */
+       unsigned chunk_bits_alt:1;      /* was allocated using alternative strategy */
+       int chunk_bit_stride;   /* Number of bytes of chunk_bits per block.
+                                * Must be consistent with chunks_per_block.
+                                */
+
+       int n_erased_blocks;
+       int alloc_block;        /* Current block being allocated off */
+       u32 alloc_page;
+       int alloc_block_finder; /* Used to search for next allocation block */
+
+       /* Object and Tnode memory management */
+       void *allocator;
+       int n_obj;
+       int n_tnodes;
+
+       int n_hardlinks;
+
+       struct yaffs_obj_bucket obj_bucket[YAFFS_NOBJECT_BUCKETS];
+       u32 bucket_finder;
+
+       int n_free_chunks;
+
+       /* Garbage collection control */
+       u32 *gc_cleanup_list;   /* objects to delete at the end of a GC. */
+       u32 n_clean_ups;
+
+       unsigned has_pending_prioritised_gc;    /* We think this device might have pending prioritised gcs */
+       unsigned gc_disable;
+       unsigned gc_block_finder;
+       unsigned gc_dirtiest;
+       unsigned gc_pages_in_use;
+       unsigned gc_not_done;
+       unsigned gc_block;
+       unsigned gc_chunk;
+       unsigned gc_skip;
+
+       /* Special directories */
+       struct yaffs_obj *root_dir;
+       struct yaffs_obj *lost_n_found;
+
+       /* Buffer areas for storing data to recover from write failures TODO
+        *      u8            buffered_data[YAFFS_CHUNKS_PER_BLOCK][YAFFS_BYTES_PER_CHUNK];
+        *      struct yaffs_spare buffered_spare[YAFFS_CHUNKS_PER_BLOCK];
+        */
+
+       int buffered_block;     /* Which block is buffered here? */
+       int doing_buffered_block_rewrite;
+
+       struct yaffs_cache *cache;
+       int cache_last_use;
+
+       /* Stuff for background deletion and unlinked files. */
+       struct yaffs_obj *unlinked_dir; /* Directory where unlinked and deleted files live. */
+       struct yaffs_obj *del_dir;      /* Directory where deleted objects are sent to disappear. */
+       struct yaffs_obj *unlinked_deletion;    /* Current file being background deleted. */
+       int n_deleted_files;    /* Count of files awaiting deletion; */
+       int n_unlinked_files;   /* Count of unlinked files. */
+       int n_bg_deletions;     /* Count of background deletions. */
+
+       /* Temporary buffer management */
+       struct yaffs_buffer temp_buffer[YAFFS_N_TEMP_BUFFERS];
+       int max_temp;
+       int temp_in_use;
+       int unmanaged_buffer_allocs;
+       int unmanaged_buffer_deallocs;
+
+       /* yaffs2 runtime stuff */
+       unsigned seq_number;    /* Sequence number of currently allocating block */
+       unsigned oldest_dirty_seq;
+       unsigned oldest_dirty_block;
+
+       /* Block refreshing */
+       int refresh_skip;       /* A skip down counter. Refresh happens when this gets to zero. */
+
+       /* Dirty directory handling */
+       struct list_head dirty_dirs;    /* List of dirty directories */
+
+       /* Statistcs */
+       u32 n_page_writes;
+       u32 n_page_reads;
+       u32 n_erasures;
+       u32 n_erase_failures;
+       u32 n_gc_copies;
+       u32 all_gcs;
+       u32 passive_gc_count;
+       u32 oldest_dirty_gc_count;
+       u32 n_gc_blocks;
+       u32 bg_gcs;
+       u32 n_retired_writes;
+       u32 n_retired_blocks;
+       u32 n_ecc_fixed;
+       u32 n_ecc_unfixed;
+       u32 n_tags_ecc_fixed;
+       u32 n_tags_ecc_unfixed;
+       u32 n_deletions;
+       u32 n_unmarked_deletions;
+       u32 refresh_count;
+       u32 cache_hits;
+
+};
+
+/* The CheckpointDevice structure holds the device information that changes at runtime and
+ * must be preserved over unmount/mount cycles.
+ */
+struct yaffs_checkpt_dev {
+       int struct_type;
+       int n_erased_blocks;
+       int alloc_block;        /* Current block being allocated off */
+       u32 alloc_page;
+       int n_free_chunks;
+
+       int n_deleted_files;    /* Count of files awaiting deletion; */
+       int n_unlinked_files;   /* Count of unlinked files. */
+       int n_bg_deletions;     /* Count of background deletions. */
+
+       /* yaffs2 runtime stuff */
+       unsigned seq_number;    /* Sequence number of currently allocating block */
+
+};
+
+struct yaffs_checkpt_validity {
+       int struct_type;
+       u32 magic;
+       u32 version;
+       u32 head;
+};
+
+struct yaffs_shadow_fixer {
+       int obj_id;
+       int shadowed_id;
+       struct yaffs_shadow_fixer *next;
+};
+
+/* Structure for doing xattr modifications */
+struct yaffs_xattr_mod {
+       int set;                /* If 0 then this is a deletion */
+       const YCHAR *name;
+       const void *data;
+       int size;
+       int flags;
+       int result;
+};
+
+/*----------------------- YAFFS Functions -----------------------*/
+
+int yaffs_guts_initialise(struct yaffs_dev *dev);
+void yaffs_deinitialise(struct yaffs_dev *dev);
+
+int yaffs_get_n_free_chunks(struct yaffs_dev *dev);
+
+int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR * old_name,
+                    struct yaffs_obj *new_dir, const YCHAR * new_name);
+
+int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR * name);
+int yaffs_del_obj(struct yaffs_obj *obj);
+
+int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR * name, int buffer_size);
+int yaffs_get_obj_length(struct yaffs_obj *obj);
+int yaffs_get_obj_inode(struct yaffs_obj *obj);
+unsigned yaffs_get_obj_type(struct yaffs_obj *obj);
+int yaffs_get_obj_link_count(struct yaffs_obj *obj);
+
+/* File operations */
+int yaffs_file_rd(struct yaffs_obj *obj, u8 * buffer, loff_t offset,
+                 int n_bytes);
+int yaffs_wr_file(struct yaffs_obj *obj, const u8 * buffer, loff_t offset,
+                 int n_bytes, int write_trhrough);
+int yaffs_resize_file(struct yaffs_obj *obj, loff_t new_size);
+
+struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
+                                   const YCHAR * name, u32 mode, u32 uid,
+                                   u32 gid);
+
+int yaffs_flush_file(struct yaffs_obj *obj, int update_time, int data_sync);
+
+/* Flushing and checkpointing */
+void yaffs_flush_whole_cache(struct yaffs_dev *dev);
+
+int yaffs_checkpoint_save(struct yaffs_dev *dev);
+int yaffs_checkpoint_restore(struct yaffs_dev *dev);
+
+/* Directory operations */
+struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR * name,
+                                  u32 mode, u32 uid, u32 gid);
+struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *the_dir,
+                                    const YCHAR * name);
+struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number);
+
+/* Link operations */
+struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR * name,
+                                struct yaffs_obj *equiv_obj);
+
+struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj);
+
+/* Symlink operations */
+struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
+                                      const YCHAR * name, u32 mode, u32 uid,
+                                      u32 gid, const YCHAR * alias);
+YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj);
+
+/* Special inodes (fifos, sockets and devices) */
+struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
+                                      const YCHAR * name, u32 mode, u32 uid,
+                                      u32 gid, u32 rdev);
+
+int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
+                     const void *value, int size, int flags);
+int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
+                     int size);
+int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size);
+int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name);
+
+/* Special directories */
+struct yaffs_obj *yaffs_root(struct yaffs_dev *dev);
+struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev);
+
+void yaffs_handle_defered_free(struct yaffs_obj *obj);
+
+void yaffs_update_dirty_dirs(struct yaffs_dev *dev);
+
+int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency);
+
+/* Debug dump  */
+int yaffs_dump_obj(struct yaffs_obj *obj);
+
+void yaffs_guts_test(struct yaffs_dev *dev);
+
+/* A few useful functions to be used within the core files*/
+void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
+                    int lyn);
+int yaffs_check_ff(u8 * buffer, int n_bytes);
+void yaffs_handle_chunk_error(struct yaffs_dev *dev,
+                             struct yaffs_block_info *bi);
+
+u8 *yaffs_get_temp_buffer(struct yaffs_dev *dev, int line_no);
+void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 * buffer, int line_no);
+
+struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
+                                                int number,
+                                                enum yaffs_obj_type type);
+int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
+                           int nand_chunk, int in_scan);
+void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR * name);
+void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
+                               const struct yaffs_obj_hdr *oh);
+void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj);
+YCHAR *yaffs_clone_str(const YCHAR * str);
+void yaffs_link_fixup(struct yaffs_dev *dev, struct yaffs_obj *hard_list);
+void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no);
+int yaffs_update_oh(struct yaffs_obj *in, const YCHAR * name,
+                   int force, int is_shrink, int shadows,
+                   struct yaffs_xattr_mod *xop);
+void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
+                              int backward_scanning);
+int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks);
+struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev);
+struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
+                                          struct yaffs_file_var *file_struct,
+                                          u32 chunk_id,
+                                          struct yaffs_tnode *passed_tn);
+
+int yaffs_do_file_wr(struct yaffs_obj *in, const u8 * buffer, loff_t offset,
+                    int n_bytes, int write_trhrough);
+void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size);
+void yaffs_skip_rest_of_block(struct yaffs_dev *dev);
+
+int yaffs_count_free_chunks(struct yaffs_dev *dev);
+
+struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
+                                      struct yaffs_file_var *file_struct,
+                                      u32 chunk_id);
+
+u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
+                        unsigned pos);
+
+int yaffs_is_non_empty_dir(struct yaffs_obj *obj);
+#endif
diff --git a/fs/yaffs2/yaffs_linux.h b/fs/yaffs2/yaffs_linux.h
new file mode 100644 (file)
index 0000000..3b508cb
--- /dev/null
@@ -0,0 +1,41 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_LINUX_H__
+#define __YAFFS_LINUX_H__
+
+#include "yportenv.h"
+
+struct yaffs_linux_context {
+       struct list_head context_list;  /* List of these we have mounted */
+       struct yaffs_dev *dev;
+       struct super_block *super;
+       struct task_struct *bg_thread;  /* Background thread for this device */
+       int bg_running;
+       struct mutex gross_lock;        /* Gross locking mutex*/
+       u8 *spare_buffer;       /* For mtdif2 use. Don't know the size of the buffer
+                                * at compile time so we have to allocate it.
+                                */
+       struct list_head search_contexts;
+       void (*put_super_fn) (struct super_block * sb);
+
+       struct task_struct *readdir_process;
+       unsigned mount_id;
+};
+
+#define yaffs_dev_to_lc(dev) ((struct yaffs_linux_context *)((dev)->os_context))
+#define yaffs_dev_to_mtd(dev) ((struct mtd_info *)((dev)->driver_context))
+
+#endif
diff --git a/fs/yaffs2/yaffs_mtdif.c b/fs/yaffs2/yaffs_mtdif.c
new file mode 100644 (file)
index 0000000..7cf53b3
--- /dev/null
@@ -0,0 +1,54 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yportenv.h"
+
+#include "yaffs_mtdif.h"
+
+#include "linux/mtd/mtd.h"
+#include "linux/types.h"
+#include "linux/time.h"
+#include "linux/mtd/nand.h"
+
+#include "yaffs_linux.h"
+
+int nandmtd_erase_block(struct yaffs_dev *dev, int block_no)
+{
+       struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
+       u32 addr =
+           ((loff_t) block_no) * dev->param.total_bytes_per_chunk
+           * dev->param.chunks_per_block;
+       struct erase_info ei;
+
+       int retval = 0;
+
+       ei.mtd = mtd;
+       ei.addr = addr;
+       ei.len = dev->param.total_bytes_per_chunk * dev->param.chunks_per_block;
+       ei.time = 1000;
+       ei.retries = 2;
+       ei.callback = NULL;
+       ei.priv = (u_long) dev;
+
+       retval = mtd->erase(mtd, &ei);
+
+       if (retval == 0)
+               return YAFFS_OK;
+       else
+               return YAFFS_FAIL;
+}
+
+int nandmtd_initialise(struct yaffs_dev *dev)
+{
+       return YAFFS_OK;
+}
diff --git a/fs/yaffs2/yaffs_mtdif.h b/fs/yaffs2/yaffs_mtdif.h
new file mode 100644 (file)
index 0000000..6665074
--- /dev/null
@@ -0,0 +1,23 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_MTDIF_H__
+#define __YAFFS_MTDIF_H__
+
+#include "yaffs_guts.h"
+
+int nandmtd_erase_block(struct yaffs_dev *dev, int block_no);
+int nandmtd_initialise(struct yaffs_dev *dev);
+#endif
diff --git a/fs/yaffs2/yaffs_mtdif1.c b/fs/yaffs2/yaffs_mtdif1.c
new file mode 100644 (file)
index 0000000..5108369
--- /dev/null
@@ -0,0 +1,330 @@
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * This module provides the interface between yaffs_nand.c and the
+ * MTD API.  This version is used when the MTD interface supports the
+ * 'mtd_oob_ops' style calls to read_oob and write_oob, circa 2.6.17,
+ * and we have small-page NAND device.
+ *
+ * These functions are invoked via function pointers in yaffs_nand.c.
+ * This replaces functionality provided by functions in yaffs_mtdif.c
+ * and the yaffs_tags compatability functions in yaffs_tagscompat.c that are
+ * called in yaffs_mtdif.c when the function pointers are NULL.
+ * We assume the MTD layer is performing ECC (use_nand_ecc is true).
+ */
+
+#include "yportenv.h"
+#include "yaffs_trace.h"
+#include "yaffs_guts.h"
+#include "yaffs_packedtags1.h"
+#include "yaffs_tagscompat.h"  /* for yaffs_calc_tags_ecc */
+#include "yaffs_linux.h"
+
+#include "linux/kernel.h"
+#include "linux/version.h"
+#include "linux/types.h"
+#include "linux/mtd/mtd.h"
+
+#ifndef CONFIG_YAFFS_9BYTE_TAGS
+# define YTAG1_SIZE 8
+#else
+# define YTAG1_SIZE 9
+#endif
+
+/* Write a chunk (page) of data to NAND.
+ *
+ * Caller always provides ExtendedTags data which are converted to a more
+ * compact (packed) form for storage in NAND.  A mini-ECC runs over the
+ * contents of the tags meta-data; used to valid the tags when read.
+ *
+ *  - Pack ExtendedTags to packed_tags1 form
+ *  - Compute mini-ECC for packed_tags1
+ *  - Write data and packed tags to NAND.
+ *
+ * Note: Due to the use of the packed_tags1 meta-data which does not include
+ * a full sequence number (as found in the larger packed_tags2 form) it is
+ * necessary for Yaffs to re-write a chunk/page (just once) to mark it as
+ * discarded and dirty.  This is not ideal: newer NAND parts are supposed
+ * to be written just once.  When Yaffs performs this operation, this
+ * function is called with a NULL data pointer -- calling MTD write_oob
+ * without data is valid usage (2.6.17).
+ *
+ * Any underlying MTD error results in YAFFS_FAIL.
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+int nandmtd1_write_chunk_tags(struct yaffs_dev *dev,
+                             int nand_chunk, const u8 * data,
+                             const struct yaffs_ext_tags *etags)
+{
+       struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
+       int chunk_bytes = dev->data_bytes_per_chunk;
+       loff_t addr = ((loff_t) nand_chunk) * chunk_bytes;
+       struct mtd_oob_ops ops;
+       struct yaffs_packed_tags1 pt1;
+       int retval;
+
+       /* we assume that packed_tags1 and struct yaffs_tags are compatible */
+       compile_time_assertion(sizeof(struct yaffs_packed_tags1) == 12);
+       compile_time_assertion(sizeof(struct yaffs_tags) == 8);
+
+       yaffs_pack_tags1(&pt1, etags);
+       yaffs_calc_tags_ecc((struct yaffs_tags *)&pt1);
+
+       /* When deleting a chunk, the upper layer provides only skeletal
+        * etags, one with is_deleted set.  However, we need to update the
+        * tags, not erase them completely.  So we use the NAND write property
+        * that only zeroed-bits stick and set tag bytes to all-ones and
+        * zero just the (not) deleted bit.
+        */
+#ifndef CONFIG_YAFFS_9BYTE_TAGS
+       if (etags->is_deleted) {
+               memset(&pt1, 0xff, 8);
+               /* clear delete status bit to indicate deleted */
+               pt1.deleted = 0;
+       }
+#else
+       ((u8 *) & pt1)[8] = 0xff;
+       if (etags->is_deleted) {
+               memset(&pt1, 0xff, 8);
+               /* zero page_status byte to indicate deleted */
+               ((u8 *) & pt1)[8] = 0;
+       }
+#endif
+
+       memset(&ops, 0, sizeof(ops));
+       ops.mode = MTD_OOB_AUTO;
+       ops.len = (data) ? chunk_bytes : 0;
+       ops.ooblen = YTAG1_SIZE;
+       ops.datbuf = (u8 *) data;
+       ops.oobbuf = (u8 *) & pt1;
+
+       retval = mtd->write_oob(mtd, addr, &ops);
+       if (retval) {
+               yaffs_trace(YAFFS_TRACE_MTD,
+                       "write_oob failed, chunk %d, mtd error %d",
+                       nand_chunk, retval);
+       }
+       return retval ? YAFFS_FAIL : YAFFS_OK;
+}
+
+/* Return with empty ExtendedTags but add ecc_result.
+ */
+static int rettags(struct yaffs_ext_tags *etags, int ecc_result, int retval)
+{
+       if (etags) {
+               memset(etags, 0, sizeof(*etags));
+               etags->ecc_result = ecc_result;
+       }
+       return retval;
+}
+
+/* Read a chunk (page) from NAND.
+ *
+ * Caller expects ExtendedTags data to be usable even on error; that is,
+ * all members except ecc_result and block_bad are zeroed.
+ *
+ *  - Check ECC results for data (if applicable)
+ *  - Check for blank/erased block (return empty ExtendedTags if blank)
+ *  - Check the packed_tags1 mini-ECC (correct if necessary/possible)
+ *  - Convert packed_tags1 to ExtendedTags
+ *  - Update ecc_result and block_bad members to refect state.
+ *
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+int nandmtd1_read_chunk_tags(struct yaffs_dev *dev,
+                            int nand_chunk, u8 * data,
+                            struct yaffs_ext_tags *etags)
+{
+       struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
+       int chunk_bytes = dev->data_bytes_per_chunk;
+       loff_t addr = ((loff_t) nand_chunk) * chunk_bytes;
+       int eccres = YAFFS_ECC_RESULT_NO_ERROR;
+       struct mtd_oob_ops ops;
+       struct yaffs_packed_tags1 pt1;
+       int retval;
+       int deleted;
+
+       memset(&ops, 0, sizeof(ops));
+       ops.mode = MTD_OOB_AUTO;
+       ops.len = (data) ? chunk_bytes : 0;
+       ops.ooblen = YTAG1_SIZE;
+       ops.datbuf = data;
+       ops.oobbuf = (u8 *) & pt1;
+
+       /* Read page and oob using MTD.
+        * Check status and determine ECC result.
+        */
+       retval = mtd->read_oob(mtd, addr, &ops);
+       if (retval) {
+               yaffs_trace(YAFFS_TRACE_MTD,
+                       "read_oob failed, chunk %d, mtd error %d",
+                       nand_chunk, retval);
+       }
+
+       switch (retval) {
+       case 0:
+               /* no error */
+               break;
+
+       case -EUCLEAN:
+               /* MTD's ECC fixed the data */
+               eccres = YAFFS_ECC_RESULT_FIXED;
+               dev->n_ecc_fixed++;
+               break;
+
+       case -EBADMSG:
+               /* MTD's ECC could not fix the data */
+               dev->n_ecc_unfixed++;
+               /* fall into... */
+       default:
+               rettags(etags, YAFFS_ECC_RESULT_UNFIXED, 0);
+               etags->block_bad = (mtd->block_isbad) (mtd, addr);
+               return YAFFS_FAIL;
+       }
+
+       /* Check for a blank/erased chunk.
+        */
+       if (yaffs_check_ff((u8 *) & pt1, 8)) {
+               /* when blank, upper layers want ecc_result to be <= NO_ERROR */
+               return rettags(etags, YAFFS_ECC_RESULT_NO_ERROR, YAFFS_OK);
+       }
+#ifndef CONFIG_YAFFS_9BYTE_TAGS
+       /* Read deleted status (bit) then return it to it's non-deleted
+        * state before performing tags mini-ECC check. pt1.deleted is
+        * inverted.
+        */
+       deleted = !pt1.deleted;
+       pt1.deleted = 1;
+#else
+       deleted = (yaffs_count_bits(((u8 *) & pt1)[8]) < 7);
+#endif
+
+       /* Check the packed tags mini-ECC and correct if necessary/possible.
+        */
+       retval = yaffs_check_tags_ecc((struct yaffs_tags *)&pt1);
+       switch (retval) {
+       case 0:
+               /* no tags error, use MTD result */
+               break;
+       case 1:
+               /* recovered tags-ECC error */
+               dev->n_tags_ecc_fixed++;
+               if (eccres == YAFFS_ECC_RESULT_NO_ERROR)
+                       eccres = YAFFS_ECC_RESULT_FIXED;
+               break;
+       default:
+               /* unrecovered tags-ECC error */
+               dev->n_tags_ecc_unfixed++;
+               return rettags(etags, YAFFS_ECC_RESULT_UNFIXED, YAFFS_FAIL);
+       }
+
+       /* Unpack the tags to extended form and set ECC result.
+        * [set should_be_ff just to keep yaffs_unpack_tags1 happy]
+        */
+       pt1.should_be_ff = 0xFFFFFFFF;
+       yaffs_unpack_tags1(etags, &pt1);
+       etags->ecc_result = eccres;
+
+       /* Set deleted state */
+       etags->is_deleted = deleted;
+       return YAFFS_OK;
+}
+
+/* Mark a block bad.
+ *
+ * This is a persistant state.
+ * Use of this function should be rare.
+ *
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+int nandmtd1_mark_block_bad(struct yaffs_dev *dev, int block_no)
+{
+       struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
+       int blocksize = dev->param.chunks_per_block * dev->data_bytes_per_chunk;
+       int retval;
+
+       yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
+               "marking block %d bad", block_no);
+
+       retval = mtd->block_markbad(mtd, (loff_t) blocksize * block_no);
+       return (retval) ? YAFFS_FAIL : YAFFS_OK;
+}
+
+/* Check any MTD prerequists.
+ *
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+static int nandmtd1_test_prerequists(struct mtd_info *mtd)
+{
+       /* 2.6.18 has mtd->ecclayout->oobavail */
+       /* 2.6.21 has mtd->ecclayout->oobavail and mtd->oobavail */
+       int oobavail = mtd->ecclayout->oobavail;
+
+       if (oobavail < YTAG1_SIZE) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                       "mtd device has only %d bytes for tags, need %d",
+                       oobavail, YTAG1_SIZE);
+               return YAFFS_FAIL;
+       }
+       return YAFFS_OK;
+}
+
+/* Query for the current state of a specific block.
+ *
+ * Examine the tags of the first chunk of the block and return the state:
+ *  - YAFFS_BLOCK_STATE_DEAD, the block is marked bad
+ *  - YAFFS_BLOCK_STATE_NEEDS_SCANNING, the block is in use
+ *  - YAFFS_BLOCK_STATE_EMPTY, the block is clean
+ *
+ * Always returns YAFFS_OK.
+ */
+int nandmtd1_query_block(struct yaffs_dev *dev, int block_no,
+                        enum yaffs_block_state *state_ptr, u32 * seq_ptr)
+{
+       struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
+       int chunk_num = block_no * dev->param.chunks_per_block;
+       loff_t addr = (loff_t) chunk_num * dev->data_bytes_per_chunk;
+       struct yaffs_ext_tags etags;
+       int state = YAFFS_BLOCK_STATE_DEAD;
+       int seqnum = 0;
+       int retval;
+
+       /* We don't yet have a good place to test for MTD config prerequists.
+        * Do it here as we are called during the initial scan.
+        */
+       if (nandmtd1_test_prerequists(mtd) != YAFFS_OK)
+               return YAFFS_FAIL;
+
+       retval = nandmtd1_read_chunk_tags(dev, chunk_num, NULL, &etags);
+       etags.block_bad = (mtd->block_isbad) (mtd, addr);
+       if (etags.block_bad) {
+               yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
+                       "block %d is marked bad", block_no);
+               state = YAFFS_BLOCK_STATE_DEAD;
+       } else if (etags.ecc_result != YAFFS_ECC_RESULT_NO_ERROR) {
+               /* bad tags, need to look more closely */
+               state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
+       } else if (etags.chunk_used) {
+               state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
+               seqnum = etags.seq_number;
+       } else {
+               state = YAFFS_BLOCK_STATE_EMPTY;
+       }
+
+       *state_ptr = state;
+       *seq_ptr = seqnum;
+
+       /* query always succeeds */
+       return YAFFS_OK;
+}
diff --git a/fs/yaffs2/yaffs_mtdif1.h b/fs/yaffs2/yaffs_mtdif1.h
new file mode 100644 (file)
index 0000000..07ce452
--- /dev/null
@@ -0,0 +1,29 @@
+/*
+ * YAFFS: Yet another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_MTDIF1_H__
+#define __YAFFS_MTDIF1_H__
+
+int nandmtd1_write_chunk_tags(struct yaffs_dev *dev, int nand_chunk,
+                             const u8 * data,
+                             const struct yaffs_ext_tags *tags);
+
+int nandmtd1_read_chunk_tags(struct yaffs_dev *dev, int nand_chunk,
+                            u8 * data, struct yaffs_ext_tags *tags);
+
+int nandmtd1_mark_block_bad(struct yaffs_dev *dev, int block_no);
+
+int nandmtd1_query_block(struct yaffs_dev *dev, int block_no,
+                        enum yaffs_block_state *state, u32 * seq_number);
+
+#endif
diff --git a/fs/yaffs2/yaffs_mtdif2.c b/fs/yaffs2/yaffs_mtdif2.c
new file mode 100644 (file)
index 0000000..d1643df
--- /dev/null
@@ -0,0 +1,225 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/* mtd interface for YAFFS2 */
+
+#include "yportenv.h"
+#include "yaffs_trace.h"
+
+#include "yaffs_mtdif2.h"
+
+#include "linux/mtd/mtd.h"
+#include "linux/types.h"
+#include "linux/time.h"
+
+#include "yaffs_packedtags2.h"
+
+#include "yaffs_linux.h"
+
+/* NB For use with inband tags....
+ * We assume that the data buffer is of size total_bytes_per_chunk so that we can also
+ * use it to load the tags.
+ */
+int nandmtd2_write_chunk_tags(struct yaffs_dev *dev, int nand_chunk,
+                             const u8 * data,
+                             const struct yaffs_ext_tags *tags)
+{
+       struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
+       struct mtd_oob_ops ops;
+       int retval = 0;
+
+       loff_t addr;
+
+       struct yaffs_packed_tags2 pt;
+
+       int packed_tags_size =
+           dev->param.no_tags_ecc ? sizeof(pt.t) : sizeof(pt);
+       void *packed_tags_ptr =
+           dev->param.no_tags_ecc ? (void *)&pt.t : (void *)&pt;
+
+       yaffs_trace(YAFFS_TRACE_MTD,
+               "nandmtd2_write_chunk_tags chunk %d data %p tags %p",
+               nand_chunk, data, tags);
+
+       addr = ((loff_t) nand_chunk) * dev->param.total_bytes_per_chunk;
+
+       /* For yaffs2 writing there must be both data and tags.
+        * If we're using inband tags, then the tags are stuffed into
+        * the end of the data buffer.
+        */
+       if (!data || !tags)
+               BUG();
+       else if (dev->param.inband_tags) {
+               struct yaffs_packed_tags2_tags_only *pt2tp;
+               pt2tp =
+                   (struct yaffs_packed_tags2_tags_only *)(data +
+                                                           dev->
+                                                           data_bytes_per_chunk);
+               yaffs_pack_tags2_tags_only(pt2tp, tags);
+       } else {
+               yaffs_pack_tags2(&pt, tags, !dev->param.no_tags_ecc);
+        }
+
+       ops.mode = MTD_OOB_AUTO;
+       ops.ooblen = (dev->param.inband_tags) ? 0 : packed_tags_size;
+       ops.len = dev->param.total_bytes_per_chunk;
+       ops.ooboffs = 0;
+       ops.datbuf = (u8 *) data;
+       ops.oobbuf = (dev->param.inband_tags) ? NULL : packed_tags_ptr;
+       retval = mtd->write_oob(mtd, addr, &ops);
+
+       if (retval == 0)
+               return YAFFS_OK;
+       else
+               return YAFFS_FAIL;
+}
+
+int nandmtd2_read_chunk_tags(struct yaffs_dev *dev, int nand_chunk,
+                            u8 * data, struct yaffs_ext_tags *tags)
+{
+       struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
+       struct mtd_oob_ops ops;
+
+       size_t dummy;
+       int retval = 0;
+       int local_data = 0;
+
+       loff_t addr = ((loff_t) nand_chunk) * dev->param.total_bytes_per_chunk;
+
+       struct yaffs_packed_tags2 pt;
+
+       int packed_tags_size =
+           dev->param.no_tags_ecc ? sizeof(pt.t) : sizeof(pt);
+       void *packed_tags_ptr =
+           dev->param.no_tags_ecc ? (void *)&pt.t : (void *)&pt;
+
+       yaffs_trace(YAFFS_TRACE_MTD,
+               "nandmtd2_read_chunk_tags chunk %d data %p tags %p",
+               nand_chunk, data, tags);
+
+       if (dev->param.inband_tags) {
+
+               if (!data) {
+                       local_data = 1;
+                       data = yaffs_get_temp_buffer(dev, __LINE__);
+               }
+
+       }
+
+       if (dev->param.inband_tags || (data && !tags))
+               retval = mtd->read(mtd, addr, dev->param.total_bytes_per_chunk,
+                                  &dummy, data);
+       else if (tags) {
+               ops.mode = MTD_OOB_AUTO;
+               ops.ooblen = packed_tags_size;
+               ops.len = data ? dev->data_bytes_per_chunk : packed_tags_size;
+               ops.ooboffs = 0;
+               ops.datbuf = data;
+               ops.oobbuf = yaffs_dev_to_lc(dev)->spare_buffer;
+               retval = mtd->read_oob(mtd, addr, &ops);
+       }
+
+       if (dev->param.inband_tags) {
+               if (tags) {
+                       struct yaffs_packed_tags2_tags_only *pt2tp;
+                       pt2tp =
+                           (struct yaffs_packed_tags2_tags_only *)&data[dev->
+                                                                        data_bytes_per_chunk];
+                       yaffs_unpack_tags2_tags_only(tags, pt2tp);
+               }
+       } else {
+               if (tags) {
+                       memcpy(packed_tags_ptr,
+                              yaffs_dev_to_lc(dev)->spare_buffer,
+                              packed_tags_size);
+                       yaffs_unpack_tags2(tags, &pt, !dev->param.no_tags_ecc);
+               }
+       }
+
+       if (local_data)
+               yaffs_release_temp_buffer(dev, data, __LINE__);
+
+       if (tags && retval == -EBADMSG
+           && tags->ecc_result == YAFFS_ECC_RESULT_NO_ERROR) {
+               tags->ecc_result = YAFFS_ECC_RESULT_UNFIXED;
+               dev->n_ecc_unfixed++;
+       }
+       if (tags && retval == -EUCLEAN
+           && tags->ecc_result == YAFFS_ECC_RESULT_NO_ERROR) {
+               tags->ecc_result = YAFFS_ECC_RESULT_FIXED;
+               dev->n_ecc_fixed++;
+       }
+       if (retval == 0)
+               return YAFFS_OK;
+       else
+               return YAFFS_FAIL;
+}
+
+int nandmtd2_mark_block_bad(struct yaffs_dev *dev, int block_no)
+{
+       struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
+       int retval;
+       yaffs_trace(YAFFS_TRACE_MTD,
+               "nandmtd2_mark_block_bad %d", block_no);
+
+       retval =
+           mtd->block_markbad(mtd,
+                              block_no * dev->param.chunks_per_block *
+                              dev->param.total_bytes_per_chunk);
+
+       if (retval == 0)
+               return YAFFS_OK;
+       else
+               return YAFFS_FAIL;
+
+}
+
+int nandmtd2_query_block(struct yaffs_dev *dev, int block_no,
+                        enum yaffs_block_state *state, u32 * seq_number)
+{
+       struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
+       int retval;
+
+       yaffs_trace(YAFFS_TRACE_MTD, "nandmtd2_query_block %d", block_no);
+       retval =
+           mtd->block_isbad(mtd,
+                            block_no * dev->param.chunks_per_block *
+                            dev->param.total_bytes_per_chunk);
+
+       if (retval) {
+               yaffs_trace(YAFFS_TRACE_MTD, "block is bad");
+
+               *state = YAFFS_BLOCK_STATE_DEAD;
+               *seq_number = 0;
+       } else {
+               struct yaffs_ext_tags t;
+               nandmtd2_read_chunk_tags(dev, block_no *
+                                        dev->param.chunks_per_block, NULL, &t);
+
+               if (t.chunk_used) {
+                       *seq_number = t.seq_number;
+                       *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
+               } else {
+                       *seq_number = 0;
+                       *state = YAFFS_BLOCK_STATE_EMPTY;
+               }
+       }
+       yaffs_trace(YAFFS_TRACE_MTD,
+               "block is bad seq %d state %d", *seq_number, *state);
+
+       if (retval == 0)
+               return YAFFS_OK;
+       else
+               return YAFFS_FAIL;
+}
+
diff --git a/fs/yaffs2/yaffs_mtdif2.h b/fs/yaffs2/yaffs_mtdif2.h
new file mode 100644 (file)
index 0000000..d821126
--- /dev/null
@@ -0,0 +1,29 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_MTDIF2_H__
+#define __YAFFS_MTDIF2_H__
+
+#include "yaffs_guts.h"
+int nandmtd2_write_chunk_tags(struct yaffs_dev *dev, int nand_chunk,
+                             const u8 * data,
+                             const struct yaffs_ext_tags *tags);
+int nandmtd2_read_chunk_tags(struct yaffs_dev *dev, int nand_chunk,
+                            u8 * data, struct yaffs_ext_tags *tags);
+int nandmtd2_mark_block_bad(struct yaffs_dev *dev, int block_no);
+int nandmtd2_query_block(struct yaffs_dev *dev, int block_no,
+                        enum yaffs_block_state *state, u32 * seq_number);
+
+#endif
diff --git a/fs/yaffs2/yaffs_nameval.c b/fs/yaffs2/yaffs_nameval.c
new file mode 100644 (file)
index 0000000..daa36f9
--- /dev/null
@@ -0,0 +1,201 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * This simple implementation of a name-value store assumes a small number of values and fits
+ * into a small finite buffer.
+ *
+ * Each attribute is stored as a record:
+ *  sizeof(int) bytes   record size.
+ *  strnlen+1 bytes name null terminated.
+ *  nbytes    value.
+ *  ----------
+ *  total size  stored in record size 
+ *
+ * This code has not been tested with unicode yet.
+ */
+
+#include "yaffs_nameval.h"
+
+#include "yportenv.h"
+
+static int nval_find(const char *xb, int xb_size, const YCHAR * name,
+                    int *exist_size)
+{
+       int pos = 0;
+       int size;
+
+       memcpy(&size, xb, sizeof(int));
+       while (size > 0 && (size < xb_size) && (pos + size < xb_size)) {
+               if (strncmp
+                   ((YCHAR *) (xb + pos + sizeof(int)), name, size) == 0) {
+                       if (exist_size)
+                               *exist_size = size;
+                       return pos;
+               }
+               pos += size;
+               if (pos < xb_size - sizeof(int))
+                       memcpy(&size, xb + pos, sizeof(int));
+               else
+                       size = 0;
+       }
+       if (exist_size)
+               *exist_size = 0;
+       return -1;
+}
+
+static int nval_used(const char *xb, int xb_size)
+{
+       int pos = 0;
+       int size;
+
+       memcpy(&size, xb + pos, sizeof(int));
+       while (size > 0 && (size < xb_size) && (pos + size < xb_size)) {
+               pos += size;
+               if (pos < xb_size - sizeof(int))
+                       memcpy(&size, xb + pos, sizeof(int));
+               else
+                       size = 0;
+       }
+       return pos;
+}
+
+int nval_del(char *xb, int xb_size, const YCHAR * name)
+{
+       int pos = nval_find(xb, xb_size, name, NULL);
+       int size;
+
+       if (pos >= 0 && pos < xb_size) {
+               /* Find size, shift rest over this record, then zero out the rest of buffer */
+               memcpy(&size, xb + pos, sizeof(int));
+               memcpy(xb + pos, xb + pos + size, xb_size - (pos + size));
+               memset(xb + (xb_size - size), 0, size);
+               return 0;
+       } else {
+               return -ENODATA;
+        }
+}
+
+int nval_set(char *xb, int xb_size, const YCHAR * name, const char *buf,
+            int bsize, int flags)
+{
+       int pos;
+       int namelen = strnlen(name, xb_size);
+       int reclen;
+       int size_exist = 0;
+       int space;
+       int start;
+
+       pos = nval_find(xb, xb_size, name, &size_exist);
+
+       if (flags & XATTR_CREATE && pos >= 0)
+               return -EEXIST;
+       if (flags & XATTR_REPLACE && pos < 0)
+               return -ENODATA;
+
+       start = nval_used(xb, xb_size);
+       space = xb_size - start + size_exist;
+
+       reclen = (sizeof(int) + namelen + 1 + bsize);
+
+       if (reclen > space)
+               return -ENOSPC;
+
+       if (pos >= 0) {
+               nval_del(xb, xb_size, name);
+               start = nval_used(xb, xb_size);
+       }
+
+       pos = start;
+
+       memcpy(xb + pos, &reclen, sizeof(int));
+       pos += sizeof(int);
+       strncpy((YCHAR *) (xb + pos), name, reclen);
+       pos += (namelen + 1);
+       memcpy(xb + pos, buf, bsize);
+       return 0;
+}
+
+int nval_get(const char *xb, int xb_size, const YCHAR * name, char *buf,
+            int bsize)
+{
+       int pos = nval_find(xb, xb_size, name, NULL);
+       int size;
+
+       if (pos >= 0 && pos < xb_size) {
+
+               memcpy(&size, xb + pos, sizeof(int));
+               pos += sizeof(int);     /* advance past record length */
+               size -= sizeof(int);
+
+               /* Advance over name string */
+               while (xb[pos] && size > 0 && pos < xb_size) {
+                       pos++;
+                       size--;
+               }
+               /*Advance over NUL */
+               pos++;
+               size--;
+
+               if (size <= bsize) {
+                       memcpy(buf, xb + pos, size);
+                       return size;
+               }
+
+       }
+       if (pos >= 0)
+               return -ERANGE;
+       else
+               return -ENODATA;
+}
+
+int nval_list(const char *xb, int xb_size, char *buf, int bsize)
+{
+       int pos = 0;
+       int size;
+       int name_len;
+       int ncopied = 0;
+       int filled = 0;
+
+       memcpy(&size, xb + pos, sizeof(int));
+       while (size > sizeof(int) && size <= xb_size && (pos + size) < xb_size
+              && !filled) {
+               pos += sizeof(int);
+               size -= sizeof(int);
+               name_len = strnlen((YCHAR *) (xb + pos), size);
+               if (ncopied + name_len + 1 < bsize) {
+                       memcpy(buf, xb + pos, name_len * sizeof(YCHAR));
+                       buf += name_len;
+                       *buf = '\0';
+                       buf++;
+                       if (sizeof(YCHAR) > 1) {
+                               *buf = '\0';
+                               buf++;
+                       }
+                       ncopied += (name_len + 1);
+               } else {
+                       filled = 1;
+                }
+               pos += size;
+               if (pos < xb_size - sizeof(int))
+                       memcpy(&size, xb + pos, sizeof(int));
+               else
+                       size = 0;
+       }
+       return ncopied;
+}
+
+int nval_hasvalues(const char *xb, int xb_size)
+{
+       return nval_used(xb, xb_size) > 0;
+}
diff --git a/fs/yaffs2/yaffs_nameval.h b/fs/yaffs2/yaffs_nameval.h
new file mode 100644 (file)
index 0000000..2bb02b6
--- /dev/null
@@ -0,0 +1,28 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __NAMEVAL_H__
+#define __NAMEVAL_H__
+
+#include "yportenv.h"
+
+int nval_del(char *xb, int xb_size, const YCHAR * name);
+int nval_set(char *xb, int xb_size, const YCHAR * name, const char *buf,
+            int bsize, int flags);
+int nval_get(const char *xb, int xb_size, const YCHAR * name, char *buf,
+            int bsize);
+int nval_list(const char *xb, int xb_size, char *buf, int bsize);
+int nval_hasvalues(const char *xb, int xb_size);
+#endif
diff --git a/fs/yaffs2/yaffs_nand.c b/fs/yaffs2/yaffs_nand.c
new file mode 100644 (file)
index 0000000..e816cab
--- /dev/null
@@ -0,0 +1,127 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_nand.h"
+#include "yaffs_tagscompat.h"
+#include "yaffs_tagsvalidity.h"
+
+#include "yaffs_getblockinfo.h"
+
+int yaffs_rd_chunk_tags_nand(struct yaffs_dev *dev, int nand_chunk,
+                            u8 * buffer, struct yaffs_ext_tags *tags)
+{
+       int result;
+       struct yaffs_ext_tags local_tags;
+
+       int realigned_chunk = nand_chunk - dev->chunk_offset;
+
+       dev->n_page_reads++;
+
+       /* If there are no tags provided, use local tags to get prioritised gc working */
+       if (!tags)
+               tags = &local_tags;
+
+       if (dev->param.read_chunk_tags_fn)
+               result =
+                   dev->param.read_chunk_tags_fn(dev, realigned_chunk, buffer,
+                                                 tags);
+       else
+               result = yaffs_tags_compat_rd(dev,
+                                             realigned_chunk, buffer, tags);
+       if (tags && tags->ecc_result > YAFFS_ECC_RESULT_NO_ERROR) {
+
+               struct yaffs_block_info *bi;
+               bi = yaffs_get_block_info(dev,
+                                         nand_chunk /
+                                         dev->param.chunks_per_block);
+               yaffs_handle_chunk_error(dev, bi);
+       }
+
+       return result;
+}
+
+int yaffs_wr_chunk_tags_nand(struct yaffs_dev *dev,
+                            int nand_chunk,
+                            const u8 * buffer, struct yaffs_ext_tags *tags)
+{
+
+       dev->n_page_writes++;
+
+       nand_chunk -= dev->chunk_offset;
+
+       if (tags) {
+               tags->seq_number = dev->seq_number;
+               tags->chunk_used = 1;
+               if (!yaffs_validate_tags(tags)) {
+                       yaffs_trace(YAFFS_TRACE_ERROR, "Writing uninitialised tags");
+                       YBUG();
+               }
+               yaffs_trace(YAFFS_TRACE_WRITE,
+                       "Writing chunk %d tags %d %d",
+                       nand_chunk, tags->obj_id, tags->chunk_id);
+       } else {
+               yaffs_trace(YAFFS_TRACE_ERROR, "Writing with no tags");
+               YBUG();
+       }
+
+       if (dev->param.write_chunk_tags_fn)
+               return dev->param.write_chunk_tags_fn(dev, nand_chunk, buffer,
+                                                     tags);
+       else
+               return yaffs_tags_compat_wr(dev, nand_chunk, buffer, tags);
+}
+
+int yaffs_mark_bad(struct yaffs_dev *dev, int block_no)
+{
+       block_no -= dev->block_offset;
+
+       if (dev->param.bad_block_fn)
+               return dev->param.bad_block_fn(dev, block_no);
+       else
+               return yaffs_tags_compat_mark_bad(dev, block_no);
+}
+
+int yaffs_query_init_block_state(struct yaffs_dev *dev,
+                                int block_no,
+                                enum yaffs_block_state *state,
+                                u32 * seq_number)
+{
+       block_no -= dev->block_offset;
+
+       if (dev->param.query_block_fn)
+               return dev->param.query_block_fn(dev, block_no, state,
+                                                seq_number);
+       else
+               return yaffs_tags_compat_query_block(dev, block_no,
+                                                    state, seq_number);
+}
+
+int yaffs_erase_block(struct yaffs_dev *dev, int flash_block)
+{
+       int result;
+
+       flash_block -= dev->block_offset;
+
+       dev->n_erasures++;
+
+       result = dev->param.erase_fn(dev, flash_block);
+
+       return result;
+}
+
+int yaffs_init_nand(struct yaffs_dev *dev)
+{
+       if (dev->param.initialise_flash_fn)
+               return dev->param.initialise_flash_fn(dev);
+       return YAFFS_OK;
+}
diff --git a/fs/yaffs2/yaffs_nand.h b/fs/yaffs2/yaffs_nand.h
new file mode 100644 (file)
index 0000000..543f198
--- /dev/null
@@ -0,0 +1,38 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_NAND_H__
+#define __YAFFS_NAND_H__
+#include "yaffs_guts.h"
+
+int yaffs_rd_chunk_tags_nand(struct yaffs_dev *dev, int nand_chunk,
+                            u8 * buffer, struct yaffs_ext_tags *tags);
+
+int yaffs_wr_chunk_tags_nand(struct yaffs_dev *dev,
+                            int nand_chunk,
+                            const u8 * buffer, struct yaffs_ext_tags *tags);
+
+int yaffs_mark_bad(struct yaffs_dev *dev, int block_no);
+
+int yaffs_query_init_block_state(struct yaffs_dev *dev,
+                                int block_no,
+                                enum yaffs_block_state *state,
+                                unsigned *seq_number);
+
+int yaffs_erase_block(struct yaffs_dev *dev, int flash_block);
+
+int yaffs_init_nand(struct yaffs_dev *dev);
+
+#endif
diff --git a/fs/yaffs2/yaffs_packedtags1.c b/fs/yaffs2/yaffs_packedtags1.c
new file mode 100644 (file)
index 0000000..a77f095
--- /dev/null
@@ -0,0 +1,53 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_packedtags1.h"
+#include "yportenv.h"
+
+void yaffs_pack_tags1(struct yaffs_packed_tags1 *pt,
+                     const struct yaffs_ext_tags *t)
+{
+       pt->chunk_id = t->chunk_id;
+       pt->serial_number = t->serial_number;
+       pt->n_bytes = t->n_bytes;
+       pt->obj_id = t->obj_id;
+       pt->ecc = 0;
+       pt->deleted = (t->is_deleted) ? 0 : 1;
+       pt->unused_stuff = 0;
+       pt->should_be_ff = 0xFFFFFFFF;
+
+}
+
+void yaffs_unpack_tags1(struct yaffs_ext_tags *t,
+                       const struct yaffs_packed_tags1 *pt)
+{
+       static const u8 all_ff[] =
+           { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+               0xff
+       };
+
+       if (memcmp(all_ff, pt, sizeof(struct yaffs_packed_tags1))) {
+               t->block_bad = 0;
+               if (pt->should_be_ff != 0xFFFFFFFF)
+                       t->block_bad = 1;
+               t->chunk_used = 1;
+               t->obj_id = pt->obj_id;
+               t->chunk_id = pt->chunk_id;
+               t->n_bytes = pt->n_bytes;
+               t->ecc_result = YAFFS_ECC_RESULT_NO_ERROR;
+               t->is_deleted = (pt->deleted) ? 0 : 1;
+               t->serial_number = pt->serial_number;
+       } else {
+               memset(t, 0, sizeof(struct yaffs_ext_tags));
+       }
+}
diff --git a/fs/yaffs2/yaffs_packedtags1.h b/fs/yaffs2/yaffs_packedtags1.h
new file mode 100644 (file)
index 0000000..d6861ff
--- /dev/null
@@ -0,0 +1,39 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+/* This is used to pack YAFFS1 tags, not YAFFS2 tags. */
+
+#ifndef __YAFFS_PACKEDTAGS1_H__
+#define __YAFFS_PACKEDTAGS1_H__
+
+#include "yaffs_guts.h"
+
+struct yaffs_packed_tags1 {
+       unsigned chunk_id:20;
+       unsigned serial_number:2;
+       unsigned n_bytes:10;
+       unsigned obj_id:18;
+       unsigned ecc:12;
+       unsigned deleted:1;
+       unsigned unused_stuff:1;
+       unsigned should_be_ff;
+
+};
+
+void yaffs_pack_tags1(struct yaffs_packed_tags1 *pt,
+                     const struct yaffs_ext_tags *t);
+void yaffs_unpack_tags1(struct yaffs_ext_tags *t,
+                       const struct yaffs_packed_tags1 *pt);
+#endif
diff --git a/fs/yaffs2/yaffs_packedtags2.c b/fs/yaffs2/yaffs_packedtags2.c
new file mode 100644 (file)
index 0000000..8e7fea3
--- /dev/null
@@ -0,0 +1,196 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_packedtags2.h"
+#include "yportenv.h"
+#include "yaffs_trace.h"
+#include "yaffs_tagsvalidity.h"
+
+/* This code packs a set of extended tags into a binary structure for
+ * NAND storage
+ */
+
+/* Some of the information is "extra" struff which can be packed in to
+ * speed scanning
+ * This is defined by having the EXTRA_HEADER_INFO_FLAG set.
+ */
+
+/* Extra flags applied to chunk_id */
+
+#define EXTRA_HEADER_INFO_FLAG 0x80000000
+#define EXTRA_SHRINK_FLAG      0x40000000
+#define EXTRA_SHADOWS_FLAG     0x20000000
+#define EXTRA_SPARE_FLAGS      0x10000000
+
+#define ALL_EXTRA_FLAGS                0xF0000000
+
+/* Also, the top 4 bits of the object Id are set to the object type. */
+#define EXTRA_OBJECT_TYPE_SHIFT (28)
+#define EXTRA_OBJECT_TYPE_MASK  ((0x0F) << EXTRA_OBJECT_TYPE_SHIFT)
+
+static void yaffs_dump_packed_tags2_tags_only(const struct
+                                             yaffs_packed_tags2_tags_only *ptt)
+{
+       yaffs_trace(YAFFS_TRACE_MTD,
+               "packed tags obj %d chunk %d byte %d seq %d",
+               ptt->obj_id, ptt->chunk_id, ptt->n_bytes, ptt->seq_number);
+}
+
+static void yaffs_dump_packed_tags2(const struct yaffs_packed_tags2 *pt)
+{
+       yaffs_dump_packed_tags2_tags_only(&pt->t);
+}
+
+static void yaffs_dump_tags2(const struct yaffs_ext_tags *t)
+{
+       yaffs_trace(YAFFS_TRACE_MTD,
+               "ext.tags eccres %d blkbad %d chused %d obj %d chunk%d byte %d del %d ser %d seq %d",
+               t->ecc_result, t->block_bad, t->chunk_used, t->obj_id,
+               t->chunk_id, t->n_bytes, t->is_deleted, t->serial_number,
+               t->seq_number);
+
+}
+
+void yaffs_pack_tags2_tags_only(struct yaffs_packed_tags2_tags_only *ptt,
+                               const struct yaffs_ext_tags *t)
+{
+       ptt->chunk_id = t->chunk_id;
+       ptt->seq_number = t->seq_number;
+       ptt->n_bytes = t->n_bytes;
+       ptt->obj_id = t->obj_id;
+
+       if (t->chunk_id == 0 && t->extra_available) {
+               /* Store the extra header info instead */
+               /* We save the parent object in the chunk_id */
+               ptt->chunk_id = EXTRA_HEADER_INFO_FLAG | t->extra_parent_id;
+               if (t->extra_is_shrink)
+                       ptt->chunk_id |= EXTRA_SHRINK_FLAG;
+               if (t->extra_shadows)
+                       ptt->chunk_id |= EXTRA_SHADOWS_FLAG;
+
+               ptt->obj_id &= ~EXTRA_OBJECT_TYPE_MASK;
+               ptt->obj_id |= (t->extra_obj_type << EXTRA_OBJECT_TYPE_SHIFT);
+
+               if (t->extra_obj_type == YAFFS_OBJECT_TYPE_HARDLINK)
+                       ptt->n_bytes = t->extra_equiv_id;
+               else if (t->extra_obj_type == YAFFS_OBJECT_TYPE_FILE)
+                       ptt->n_bytes = t->extra_length;
+               else
+                       ptt->n_bytes = 0;
+       }
+
+       yaffs_dump_packed_tags2_tags_only(ptt);
+       yaffs_dump_tags2(t);
+}
+
+void yaffs_pack_tags2(struct yaffs_packed_tags2 *pt,
+                     const struct yaffs_ext_tags *t, int tags_ecc)
+{
+       yaffs_pack_tags2_tags_only(&pt->t, t);
+
+       if (tags_ecc)
+               yaffs_ecc_calc_other((unsigned char *)&pt->t,
+                                    sizeof(struct
+                                           yaffs_packed_tags2_tags_only),
+                                    &pt->ecc);
+}
+
+void yaffs_unpack_tags2_tags_only(struct yaffs_ext_tags *t,
+                                 struct yaffs_packed_tags2_tags_only *ptt)
+{
+
+       memset(t, 0, sizeof(struct yaffs_ext_tags));
+
+       yaffs_init_tags(t);
+
+       if (ptt->seq_number != 0xFFFFFFFF) {
+               t->block_bad = 0;
+               t->chunk_used = 1;
+               t->obj_id = ptt->obj_id;
+               t->chunk_id = ptt->chunk_id;
+               t->n_bytes = ptt->n_bytes;
+               t->is_deleted = 0;
+               t->serial_number = 0;
+               t->seq_number = ptt->seq_number;
+
+               /* Do extra header info stuff */
+
+               if (ptt->chunk_id & EXTRA_HEADER_INFO_FLAG) {
+                       t->chunk_id = 0;
+                       t->n_bytes = 0;
+
+                       t->extra_available = 1;
+                       t->extra_parent_id =
+                           ptt->chunk_id & (~(ALL_EXTRA_FLAGS));
+                       t->extra_is_shrink =
+                           (ptt->chunk_id & EXTRA_SHRINK_FLAG) ? 1 : 0;
+                       t->extra_shadows =
+                           (ptt->chunk_id & EXTRA_SHADOWS_FLAG) ? 1 : 0;
+                       t->extra_obj_type =
+                           ptt->obj_id >> EXTRA_OBJECT_TYPE_SHIFT;
+                       t->obj_id &= ~EXTRA_OBJECT_TYPE_MASK;
+
+                       if (t->extra_obj_type == YAFFS_OBJECT_TYPE_HARDLINK)
+                               t->extra_equiv_id = ptt->n_bytes;
+                       else
+                               t->extra_length = ptt->n_bytes;
+               }
+       }
+
+       yaffs_dump_packed_tags2_tags_only(ptt);
+       yaffs_dump_tags2(t);
+
+}
+
+void yaffs_unpack_tags2(struct yaffs_ext_tags *t, struct yaffs_packed_tags2 *pt,
+                       int tags_ecc)
+{
+
+       enum yaffs_ecc_result ecc_result = YAFFS_ECC_RESULT_NO_ERROR;
+
+       if (pt->t.seq_number != 0xFFFFFFFF && tags_ecc) {
+               /* Chunk is in use and we need to do ECC */
+
+               struct yaffs_ecc_other ecc;
+               int result;
+               yaffs_ecc_calc_other((unsigned char *)&pt->t,
+                                    sizeof(struct
+                                           yaffs_packed_tags2_tags_only),
+                                    &ecc);
+               result =
+                   yaffs_ecc_correct_other((unsigned char *)&pt->t,
+                                           sizeof(struct
+                                                  yaffs_packed_tags2_tags_only),
+                                           &pt->ecc, &ecc);
+               switch (result) {
+               case 0:
+                       ecc_result = YAFFS_ECC_RESULT_NO_ERROR;
+                       break;
+               case 1:
+                       ecc_result = YAFFS_ECC_RESULT_FIXED;
+                       break;
+               case -1:
+                       ecc_result = YAFFS_ECC_RESULT_UNFIXED;
+                       break;
+               default:
+                       ecc_result = YAFFS_ECC_RESULT_UNKNOWN;
+               }
+       }
+
+       yaffs_unpack_tags2_tags_only(t, &pt->t);
+
+       t->ecc_result = ecc_result;
+
+       yaffs_dump_packed_tags2(pt);
+       yaffs_dump_tags2(t);
+}
diff --git a/fs/yaffs2/yaffs_packedtags2.h b/fs/yaffs2/yaffs_packedtags2.h
new file mode 100644 (file)
index 0000000..f329669
--- /dev/null
@@ -0,0 +1,47 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+/* This is used to pack YAFFS2 tags, not YAFFS1tags. */
+
+#ifndef __YAFFS_PACKEDTAGS2_H__
+#define __YAFFS_PACKEDTAGS2_H__
+
+#include "yaffs_guts.h"
+#include "yaffs_ecc.h"
+
+struct yaffs_packed_tags2_tags_only {
+       unsigned seq_number;
+       unsigned obj_id;
+       unsigned chunk_id;
+       unsigned n_bytes;
+};
+
+struct yaffs_packed_tags2 {
+       struct yaffs_packed_tags2_tags_only t;
+       struct yaffs_ecc_other ecc;
+};
+
+/* Full packed tags with ECC, used for oob tags */
+void yaffs_pack_tags2(struct yaffs_packed_tags2 *pt,
+                     const struct yaffs_ext_tags *t, int tags_ecc);
+void yaffs_unpack_tags2(struct yaffs_ext_tags *t, struct yaffs_packed_tags2 *pt,
+                       int tags_ecc);
+
+/* Only the tags part (no ECC for use with inband tags */
+void yaffs_pack_tags2_tags_only(struct yaffs_packed_tags2_tags_only *pt,
+                               const struct yaffs_ext_tags *t);
+void yaffs_unpack_tags2_tags_only(struct yaffs_ext_tags *t,
+                                 struct yaffs_packed_tags2_tags_only *pt);
+#endif
diff --git a/fs/yaffs2/yaffs_tagscompat.c b/fs/yaffs2/yaffs_tagscompat.c
new file mode 100644 (file)
index 0000000..7578075
--- /dev/null
@@ -0,0 +1,422 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_guts.h"
+#include "yaffs_tagscompat.h"
+#include "yaffs_ecc.h"
+#include "yaffs_getblockinfo.h"
+#include "yaffs_trace.h"
+
+static void yaffs_handle_rd_data_error(struct yaffs_dev *dev, int nand_chunk);
+
+
+/********** Tags ECC calculations  *********/
+
+void yaffs_calc_ecc(const u8 * data, struct yaffs_spare *spare)
+{
+       yaffs_ecc_cacl(data, spare->ecc1);
+       yaffs_ecc_cacl(&data[256], spare->ecc2);
+}
+
+void yaffs_calc_tags_ecc(struct yaffs_tags *tags)
+{
+       /* Calculate an ecc */
+
+       unsigned char *b = ((union yaffs_tags_union *)tags)->as_bytes;
+       unsigned i, j;
+       unsigned ecc = 0;
+       unsigned bit = 0;
+
+       tags->ecc = 0;
+
+       for (i = 0; i < 8; i++) {
+               for (j = 1; j & 0xff; j <<= 1) {
+                       bit++;
+                       if (b[i] & j)
+                               ecc ^= bit;
+               }
+       }
+
+       tags->ecc = ecc;
+
+}
+
+int yaffs_check_tags_ecc(struct yaffs_tags *tags)
+{
+       unsigned ecc = tags->ecc;
+
+       yaffs_calc_tags_ecc(tags);
+
+       ecc ^= tags->ecc;
+
+       if (ecc && ecc <= 64) {
+               /* TODO: Handle the failure better. Retire? */
+               unsigned char *b = ((union yaffs_tags_union *)tags)->as_bytes;
+
+               ecc--;
+
+               b[ecc / 8] ^= (1 << (ecc & 7));
+
+               /* Now recvalc the ecc */
+               yaffs_calc_tags_ecc(tags);
+
+               return 1;       /* recovered error */
+       } else if (ecc) {
+               /* Wierd ecc failure value */
+               /* TODO Need to do somethiong here */
+               return -1;      /* unrecovered error */
+       }
+
+       return 0;
+}
+
+/********** Tags **********/
+
+static void yaffs_load_tags_to_spare(struct yaffs_spare *spare_ptr,
+                                    struct yaffs_tags *tags_ptr)
+{
+       union yaffs_tags_union *tu = (union yaffs_tags_union *)tags_ptr;
+
+       yaffs_calc_tags_ecc(tags_ptr);
+
+       spare_ptr->tb0 = tu->as_bytes[0];
+       spare_ptr->tb1 = tu->as_bytes[1];
+       spare_ptr->tb2 = tu->as_bytes[2];
+       spare_ptr->tb3 = tu->as_bytes[3];
+       spare_ptr->tb4 = tu->as_bytes[4];
+       spare_ptr->tb5 = tu->as_bytes[5];
+       spare_ptr->tb6 = tu->as_bytes[6];
+       spare_ptr->tb7 = tu->as_bytes[7];
+}
+
+static void yaffs_get_tags_from_spare(struct yaffs_dev *dev,
+                                     struct yaffs_spare *spare_ptr,
+                                     struct yaffs_tags *tags_ptr)
+{
+       union yaffs_tags_union *tu = (union yaffs_tags_union *)tags_ptr;
+       int result;
+
+       tu->as_bytes[0] = spare_ptr->tb0;
+       tu->as_bytes[1] = spare_ptr->tb1;
+       tu->as_bytes[2] = spare_ptr->tb2;
+       tu->as_bytes[3] = spare_ptr->tb3;
+       tu->as_bytes[4] = spare_ptr->tb4;
+       tu->as_bytes[5] = spare_ptr->tb5;
+       tu->as_bytes[6] = spare_ptr->tb6;
+       tu->as_bytes[7] = spare_ptr->tb7;
+
+       result = yaffs_check_tags_ecc(tags_ptr);
+       if (result > 0)
+               dev->n_tags_ecc_fixed++;
+       else if (result < 0)
+               dev->n_tags_ecc_unfixed++;
+}
+
+static void yaffs_spare_init(struct yaffs_spare *spare)
+{
+       memset(spare, 0xFF, sizeof(struct yaffs_spare));
+}
+
+static int yaffs_wr_nand(struct yaffs_dev *dev,
+                        int nand_chunk, const u8 * data,
+                        struct yaffs_spare *spare)
+{
+       if (nand_chunk < dev->param.start_block * dev->param.chunks_per_block) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                       "**>> yaffs chunk %d is not valid",
+                       nand_chunk);
+               return YAFFS_FAIL;
+       }
+
+       return dev->param.write_chunk_fn(dev, nand_chunk, data, spare);
+}
+
+static int yaffs_rd_chunk_nand(struct yaffs_dev *dev,
+                              int nand_chunk,
+                              u8 * data,
+                              struct yaffs_spare *spare,
+                              enum yaffs_ecc_result *ecc_result,
+                              int correct_errors)
+{
+       int ret_val;
+       struct yaffs_spare local_spare;
+
+       if (!spare && data) {
+               /* If we don't have a real spare, then we use a local one. */
+               /* Need this for the calculation of the ecc */
+               spare = &local_spare;
+       }
+
+       if (!dev->param.use_nand_ecc) {
+               ret_val =
+                   dev->param.read_chunk_fn(dev, nand_chunk, data, spare);
+               if (data && correct_errors) {
+                       /* Do ECC correction */
+                       /* Todo handle any errors */
+                       int ecc_result1, ecc_result2;
+                       u8 calc_ecc[3];
+
+                       yaffs_ecc_cacl(data, calc_ecc);
+                       ecc_result1 =
+                           yaffs_ecc_correct(data, spare->ecc1, calc_ecc);
+                       yaffs_ecc_cacl(&data[256], calc_ecc);
+                       ecc_result2 =
+                           yaffs_ecc_correct(&data[256], spare->ecc2,
+                                             calc_ecc);
+
+                       if (ecc_result1 > 0) {
+                               yaffs_trace(YAFFS_TRACE_ERROR,
+                                       "**>>yaffs ecc error fix performed on chunk %d:0",
+                                       nand_chunk);
+                               dev->n_ecc_fixed++;
+                       } else if (ecc_result1 < 0) {
+                               yaffs_trace(YAFFS_TRACE_ERROR,
+                                       "**>>yaffs ecc error unfixed on chunk %d:0",
+                                       nand_chunk);
+                               dev->n_ecc_unfixed++;
+                       }
+
+                       if (ecc_result2 > 0) {
+                               yaffs_trace(YAFFS_TRACE_ERROR,
+                                       "**>>yaffs ecc error fix performed on chunk %d:1",
+                                       nand_chunk);
+                               dev->n_ecc_fixed++;
+                       } else if (ecc_result2 < 0) {
+                               yaffs_trace(YAFFS_TRACE_ERROR,
+                                       "**>>yaffs ecc error unfixed on chunk %d:1",
+                                       nand_chunk);
+                               dev->n_ecc_unfixed++;
+                       }
+
+                       if (ecc_result1 || ecc_result2) {
+                               /* We had a data problem on this page */
+                               yaffs_handle_rd_data_error(dev, nand_chunk);
+                       }
+
+                       if (ecc_result1 < 0 || ecc_result2 < 0)
+                               *ecc_result = YAFFS_ECC_RESULT_UNFIXED;
+                       else if (ecc_result1 > 0 || ecc_result2 > 0)
+                               *ecc_result = YAFFS_ECC_RESULT_FIXED;
+                       else
+                               *ecc_result = YAFFS_ECC_RESULT_NO_ERROR;
+               }
+       } else {
+               /* Must allocate enough memory for spare+2*sizeof(int) */
+               /* for ecc results from device. */
+               struct yaffs_nand_spare nspare;
+
+               memset(&nspare, 0, sizeof(nspare));
+
+               ret_val = dev->param.read_chunk_fn(dev, nand_chunk, data,
+                                                  (struct yaffs_spare *)
+                                                  &nspare);
+               memcpy(spare, &nspare, sizeof(struct yaffs_spare));
+               if (data && correct_errors) {
+                       if (nspare.eccres1 > 0) {
+                               yaffs_trace(YAFFS_TRACE_ERROR,
+                                       "**>>mtd ecc error fix performed on chunk %d:0",
+                                       nand_chunk);
+                       } else if (nspare.eccres1 < 0) {
+                               yaffs_trace(YAFFS_TRACE_ERROR,
+                                       "**>>mtd ecc error unfixed on chunk %d:0",
+                                       nand_chunk);
+                       }
+
+                       if (nspare.eccres2 > 0) {
+                               yaffs_trace(YAFFS_TRACE_ERROR,
+                                       "**>>mtd ecc error fix performed on chunk %d:1",
+                                       nand_chunk);
+                       } else if (nspare.eccres2 < 0) {
+                               yaffs_trace(YAFFS_TRACE_ERROR,
+                                       "**>>mtd ecc error unfixed on chunk %d:1",
+                                       nand_chunk);
+                       }
+
+                       if (nspare.eccres1 || nspare.eccres2) {
+                               /* We had a data problem on this page */
+                               yaffs_handle_rd_data_error(dev, nand_chunk);
+                       }
+
+                       if (nspare.eccres1 < 0 || nspare.eccres2 < 0)
+                               *ecc_result = YAFFS_ECC_RESULT_UNFIXED;
+                       else if (nspare.eccres1 > 0 || nspare.eccres2 > 0)
+                               *ecc_result = YAFFS_ECC_RESULT_FIXED;
+                       else
+                               *ecc_result = YAFFS_ECC_RESULT_NO_ERROR;
+
+               }
+       }
+       return ret_val;
+}
+
+/*
+ * Functions for robustisizing
+ */
+
+static void yaffs_handle_rd_data_error(struct yaffs_dev *dev, int nand_chunk)
+{
+       int flash_block = nand_chunk / dev->param.chunks_per_block;
+
+       /* Mark the block for retirement */
+       yaffs_get_block_info(dev,
+                            flash_block + dev->block_offset)->needs_retiring =
+           1;
+       yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
+               "**>>Block %d marked for retirement",
+               flash_block);
+
+       /* TODO:
+        * Just do a garbage collection on the affected block
+        * then retire the block
+        * NB recursion
+        */
+}
+
+int yaffs_tags_compat_wr(struct yaffs_dev *dev,
+                        int nand_chunk,
+                        const u8 * data, const struct yaffs_ext_tags *ext_tags)
+{
+       struct yaffs_spare spare;
+       struct yaffs_tags tags;
+
+       yaffs_spare_init(&spare);
+
+       if (ext_tags->is_deleted)
+               spare.page_status = 0;
+       else {
+               tags.obj_id = ext_tags->obj_id;
+               tags.chunk_id = ext_tags->chunk_id;
+
+               tags.n_bytes_lsb = ext_tags->n_bytes & 0x3ff;
+
+               if (dev->data_bytes_per_chunk >= 1024)
+                       tags.n_bytes_msb = (ext_tags->n_bytes >> 10) & 3;
+               else
+                       tags.n_bytes_msb = 3;
+
+               tags.serial_number = ext_tags->serial_number;
+
+               if (!dev->param.use_nand_ecc && data)
+                       yaffs_calc_ecc(data, &spare);
+
+               yaffs_load_tags_to_spare(&spare, &tags);
+
+       }
+
+       return yaffs_wr_nand(dev, nand_chunk, data, &spare);
+}
+
+int yaffs_tags_compat_rd(struct yaffs_dev *dev,
+                        int nand_chunk,
+                        u8 * data, struct yaffs_ext_tags *ext_tags)
+{
+
+       struct yaffs_spare spare;
+       struct yaffs_tags tags;
+       enum yaffs_ecc_result ecc_result = YAFFS_ECC_RESULT_UNKNOWN;
+
+       static struct yaffs_spare spare_ff;
+       static int init;
+
+       if (!init) {
+               memset(&spare_ff, 0xFF, sizeof(spare_ff));
+               init = 1;
+       }
+
+       if (yaffs_rd_chunk_nand(dev, nand_chunk, data, &spare, &ecc_result, 1)) {
+               /* ext_tags may be NULL */
+               if (ext_tags) {
+
+                       int deleted =
+                           (hweight8(spare.page_status) < 7) ? 1 : 0;
+
+                       ext_tags->is_deleted = deleted;
+                       ext_tags->ecc_result = ecc_result;
+                       ext_tags->block_bad = 0;        /* We're reading it */
+                       /* therefore it is not a bad block */
+                       ext_tags->chunk_used =
+                           (memcmp(&spare_ff, &spare, sizeof(spare_ff)) !=
+                            0) ? 1 : 0;
+
+                       if (ext_tags->chunk_used) {
+                               yaffs_get_tags_from_spare(dev, &spare, &tags);
+
+                               ext_tags->obj_id = tags.obj_id;
+                               ext_tags->chunk_id = tags.chunk_id;
+                               ext_tags->n_bytes = tags.n_bytes_lsb;
+
+                               if (dev->data_bytes_per_chunk >= 1024)
+                                       ext_tags->n_bytes |=
+                                           (((unsigned)tags.
+                                             n_bytes_msb) << 10);
+
+                               ext_tags->serial_number = tags.serial_number;
+                       }
+               }
+
+               return YAFFS_OK;
+       } else {
+               return YAFFS_FAIL;
+       }
+}
+
+int yaffs_tags_compat_mark_bad(struct yaffs_dev *dev, int flash_block)
+{
+
+       struct yaffs_spare spare;
+
+       memset(&spare, 0xff, sizeof(struct yaffs_spare));
+
+       spare.block_status = 'Y';
+
+       yaffs_wr_nand(dev, flash_block * dev->param.chunks_per_block, NULL,
+                     &spare);
+       yaffs_wr_nand(dev, flash_block * dev->param.chunks_per_block + 1,
+                     NULL, &spare);
+
+       return YAFFS_OK;
+
+}
+
+int yaffs_tags_compat_query_block(struct yaffs_dev *dev,
+                                 int block_no,
+                                 enum yaffs_block_state *state,
+                                 u32 * seq_number)
+{
+
+       struct yaffs_spare spare0, spare1;
+       static struct yaffs_spare spare_ff;
+       static int init;
+       enum yaffs_ecc_result dummy;
+
+       if (!init) {
+               memset(&spare_ff, 0xFF, sizeof(spare_ff));
+               init = 1;
+       }
+
+       *seq_number = 0;
+
+       yaffs_rd_chunk_nand(dev, block_no * dev->param.chunks_per_block, NULL,
+                           &spare0, &dummy, 1);
+       yaffs_rd_chunk_nand(dev, block_no * dev->param.chunks_per_block + 1,
+                           NULL, &spare1, &dummy, 1);
+
+       if (hweight8(spare0.block_status & spare1.block_status) < 7)
+               *state = YAFFS_BLOCK_STATE_DEAD;
+       else if (memcmp(&spare_ff, &spare0, sizeof(spare_ff)) == 0)
+               *state = YAFFS_BLOCK_STATE_EMPTY;
+       else
+               *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
+
+       return YAFFS_OK;
+}
diff --git a/fs/yaffs2/yaffs_tagscompat.h b/fs/yaffs2/yaffs_tagscompat.h
new file mode 100644 (file)
index 0000000..8cd35dc
--- /dev/null
@@ -0,0 +1,36 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_TAGSCOMPAT_H__
+#define __YAFFS_TAGSCOMPAT_H__
+
+#include "yaffs_guts.h"
+int yaffs_tags_compat_wr(struct yaffs_dev *dev,
+                        int nand_chunk,
+                        const u8 * data, const struct yaffs_ext_tags *tags);
+int yaffs_tags_compat_rd(struct yaffs_dev *dev,
+                        int nand_chunk,
+                        u8 * data, struct yaffs_ext_tags *tags);
+int yaffs_tags_compat_mark_bad(struct yaffs_dev *dev, int block_no);
+int yaffs_tags_compat_query_block(struct yaffs_dev *dev,
+                                 int block_no,
+                                 enum yaffs_block_state *state,
+                                 u32 * seq_number);
+
+void yaffs_calc_tags_ecc(struct yaffs_tags *tags);
+int yaffs_check_tags_ecc(struct yaffs_tags *tags);
+int yaffs_count_bits(u8 byte);
+
+#endif
diff --git a/fs/yaffs2/yaffs_tagsvalidity.c b/fs/yaffs2/yaffs_tagsvalidity.c
new file mode 100644 (file)
index 0000000..4358d79
--- /dev/null
@@ -0,0 +1,27 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_tagsvalidity.h"
+
+void yaffs_init_tags(struct yaffs_ext_tags *tags)
+{
+       memset(tags, 0, sizeof(struct yaffs_ext_tags));
+       tags->validity0 = 0xAAAAAAAA;
+       tags->validity1 = 0x55555555;
+}
+
+int yaffs_validate_tags(struct yaffs_ext_tags *tags)
+{
+       return (tags->validity0 == 0xAAAAAAAA && tags->validity1 == 0x55555555);
+
+}
diff --git a/fs/yaffs2/yaffs_tagsvalidity.h b/fs/yaffs2/yaffs_tagsvalidity.h
new file mode 100644 (file)
index 0000000..36a021f
--- /dev/null
@@ -0,0 +1,23 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_TAGS_VALIDITY_H__
+#define __YAFFS_TAGS_VALIDITY_H__
+
+#include "yaffs_guts.h"
+
+void yaffs_init_tags(struct yaffs_ext_tags *tags);
+int yaffs_validate_tags(struct yaffs_ext_tags *tags);
+#endif
diff --git a/fs/yaffs2/yaffs_trace.h b/fs/yaffs2/yaffs_trace.h
new file mode 100644 (file)
index 0000000..6273dbf
--- /dev/null
@@ -0,0 +1,57 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YTRACE_H__
+#define __YTRACE_H__
+
+extern unsigned int yaffs_trace_mask;
+extern unsigned int yaffs_wr_attempts;
+
+/*
+ * Tracing flags.
+ * The flags masked in YAFFS_TRACE_ALWAYS are always traced.
+ */
+
+#define YAFFS_TRACE_OS                 0x00000002
+#define YAFFS_TRACE_ALLOCATE           0x00000004
+#define YAFFS_TRACE_SCAN               0x00000008
+#define YAFFS_TRACE_BAD_BLOCKS         0x00000010
+#define YAFFS_TRACE_ERASE              0x00000020
+#define YAFFS_TRACE_GC                 0x00000040
+#define YAFFS_TRACE_WRITE              0x00000080
+#define YAFFS_TRACE_TRACING            0x00000100
+#define YAFFS_TRACE_DELETION           0x00000200
+#define YAFFS_TRACE_BUFFERS            0x00000400
+#define YAFFS_TRACE_NANDACCESS         0x00000800
+#define YAFFS_TRACE_GC_DETAIL          0x00001000
+#define YAFFS_TRACE_SCAN_DEBUG         0x00002000
+#define YAFFS_TRACE_MTD                        0x00004000
+#define YAFFS_TRACE_CHECKPOINT         0x00008000
+
+#define YAFFS_TRACE_VERIFY             0x00010000
+#define YAFFS_TRACE_VERIFY_NAND                0x00020000
+#define YAFFS_TRACE_VERIFY_FULL                0x00040000
+#define YAFFS_TRACE_VERIFY_ALL         0x000F0000
+
+#define YAFFS_TRACE_SYNC               0x00100000
+#define YAFFS_TRACE_BACKGROUND         0x00200000
+#define YAFFS_TRACE_LOCK               0x00400000
+#define YAFFS_TRACE_MOUNT              0x00800000
+
+#define YAFFS_TRACE_ERROR              0x40000000
+#define YAFFS_TRACE_BUG                        0x80000000
+#define YAFFS_TRACE_ALWAYS             0xF0000000
+
+#endif
diff --git a/fs/yaffs2/yaffs_verify.c b/fs/yaffs2/yaffs_verify.c
new file mode 100644 (file)
index 0000000..738c7f6
--- /dev/null
@@ -0,0 +1,535 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_verify.h"
+#include "yaffs_trace.h"
+#include "yaffs_bitmap.h"
+#include "yaffs_getblockinfo.h"
+#include "yaffs_nand.h"
+
+int yaffs_skip_verification(struct yaffs_dev *dev)
+{
+       dev = dev;
+       return !(yaffs_trace_mask &
+                (YAFFS_TRACE_VERIFY | YAFFS_TRACE_VERIFY_FULL));
+}
+
+static int yaffs_skip_full_verification(struct yaffs_dev *dev)
+{
+       dev = dev;
+       return !(yaffs_trace_mask & (YAFFS_TRACE_VERIFY_FULL));
+}
+
+static int yaffs_skip_nand_verification(struct yaffs_dev *dev)
+{
+       dev = dev;
+       return !(yaffs_trace_mask & (YAFFS_TRACE_VERIFY_NAND));
+}
+
+static const char *block_state_name[] = {
+       "Unknown",
+       "Needs scanning",
+       "Scanning",
+       "Empty",
+       "Allocating",
+       "Full",
+       "Dirty",
+       "Checkpoint",
+       "Collecting",
+       "Dead"
+};
+
+void yaffs_verify_blk(struct yaffs_dev *dev, struct yaffs_block_info *bi, int n)
+{
+       int actually_used;
+       int in_use;
+
+       if (yaffs_skip_verification(dev))
+               return;
+
+       /* Report illegal runtime states */
+       if (bi->block_state >= YAFFS_NUMBER_OF_BLOCK_STATES)
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Block %d has undefined state %d",
+                       n, bi->block_state);
+
+       switch (bi->block_state) {
+       case YAFFS_BLOCK_STATE_UNKNOWN:
+       case YAFFS_BLOCK_STATE_SCANNING:
+       case YAFFS_BLOCK_STATE_NEEDS_SCANNING:
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Block %d has bad run-state %s",
+                       n, block_state_name[bi->block_state]);
+       }
+
+       /* Check pages in use and soft deletions are legal */
+
+       actually_used = bi->pages_in_use - bi->soft_del_pages;
+
+       if (bi->pages_in_use < 0
+           || bi->pages_in_use > dev->param.chunks_per_block
+           || bi->soft_del_pages < 0
+           || bi->soft_del_pages > dev->param.chunks_per_block
+           || actually_used < 0 || actually_used > dev->param.chunks_per_block)
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Block %d has illegal values pages_in_used %d soft_del_pages %d",
+                       n, bi->pages_in_use, bi->soft_del_pages);
+
+       /* Check chunk bitmap legal */
+       in_use = yaffs_count_chunk_bits(dev, n);
+       if (in_use != bi->pages_in_use)
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Block %d has inconsistent values pages_in_use %d counted chunk bits %d",
+                       n, bi->pages_in_use, in_use);
+
+}
+
+void yaffs_verify_collected_blk(struct yaffs_dev *dev,
+                               struct yaffs_block_info *bi, int n)
+{
+       yaffs_verify_blk(dev, bi, n);
+
+       /* After collection the block should be in the erased state */
+
+       if (bi->block_state != YAFFS_BLOCK_STATE_COLLECTING &&
+           bi->block_state != YAFFS_BLOCK_STATE_EMPTY) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                       "Block %d is in state %d after gc, should be erased",
+                       n, bi->block_state);
+       }
+}
+
+void yaffs_verify_blocks(struct yaffs_dev *dev)
+{
+       int i;
+       int state_count[YAFFS_NUMBER_OF_BLOCK_STATES];
+       int illegal_states = 0;
+
+       if (yaffs_skip_verification(dev))
+               return;
+
+       memset(state_count, 0, sizeof(state_count));
+
+       for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
+               struct yaffs_block_info *bi = yaffs_get_block_info(dev, i);
+               yaffs_verify_blk(dev, bi, i);
+
+               if (bi->block_state < YAFFS_NUMBER_OF_BLOCK_STATES)
+                       state_count[bi->block_state]++;
+               else
+                       illegal_states++;
+       }
+
+       yaffs_trace(YAFFS_TRACE_VERIFY, "Block summary");
+
+       yaffs_trace(YAFFS_TRACE_VERIFY,
+               "%d blocks have illegal states",
+               illegal_states);
+       if (state_count[YAFFS_BLOCK_STATE_ALLOCATING] > 1)
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Too many allocating blocks");
+
+       for (i = 0; i < YAFFS_NUMBER_OF_BLOCK_STATES; i++)
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "%s %d blocks",
+                       block_state_name[i], state_count[i]);
+
+       if (dev->blocks_in_checkpt != state_count[YAFFS_BLOCK_STATE_CHECKPOINT])
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Checkpoint block count wrong dev %d count %d",
+                       dev->blocks_in_checkpt,
+                       state_count[YAFFS_BLOCK_STATE_CHECKPOINT]);
+
+       if (dev->n_erased_blocks != state_count[YAFFS_BLOCK_STATE_EMPTY])
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Erased block count wrong dev %d count %d",
+                       dev->n_erased_blocks,
+                       state_count[YAFFS_BLOCK_STATE_EMPTY]);
+
+       if (state_count[YAFFS_BLOCK_STATE_COLLECTING] > 1)
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Too many collecting blocks %d (max is 1)",
+                       state_count[YAFFS_BLOCK_STATE_COLLECTING]);
+}
+
+/*
+ * Verify the object header. oh must be valid, but obj and tags may be NULL in which
+ * case those tests will not be performed.
+ */
+void yaffs_verify_oh(struct yaffs_obj *obj, struct yaffs_obj_hdr *oh,
+                    struct yaffs_ext_tags *tags, int parent_check)
+{
+       if (obj && yaffs_skip_verification(obj->my_dev))
+               return;
+
+       if (!(tags && obj && oh)) {
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Verifying object header tags %p obj %p oh %p",
+                       tags, obj, oh);
+               return;
+       }
+
+       if (oh->type <= YAFFS_OBJECT_TYPE_UNKNOWN ||
+           oh->type > YAFFS_OBJECT_TYPE_MAX)
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Obj %d header type is illegal value 0x%x",
+                       tags->obj_id, oh->type);
+
+       if (tags->obj_id != obj->obj_id)
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Obj %d header mismatch obj_id %d",
+                       tags->obj_id, obj->obj_id);
+
+       /*
+        * Check that the object's parent ids match if parent_check requested.
+        *
+        * Tests do not apply to the root object.
+        */
+
+       if (parent_check && tags->obj_id > 1 && !obj->parent)
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Obj %d header mismatch parent_id %d obj->parent is NULL",
+                       tags->obj_id, oh->parent_obj_id);
+
+       if (parent_check && obj->parent &&
+           oh->parent_obj_id != obj->parent->obj_id &&
+           (oh->parent_obj_id != YAFFS_OBJECTID_UNLINKED ||
+            obj->parent->obj_id != YAFFS_OBJECTID_DELETED))
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Obj %d header mismatch parent_id %d parent_obj_id %d",
+                       tags->obj_id, oh->parent_obj_id,
+                       obj->parent->obj_id);
+
+       if (tags->obj_id > 1 && oh->name[0] == 0)       /* Null name */
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Obj %d header name is NULL",
+                       obj->obj_id);
+
+       if (tags->obj_id > 1 && ((u8) (oh->name[0])) == 0xff)   /* Trashed name */
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Obj %d header name is 0xFF",
+                       obj->obj_id);
+}
+
+void yaffs_verify_file(struct yaffs_obj *obj)
+{
+       int required_depth;
+       int actual_depth;
+       u32 last_chunk;
+       u32 x;
+       u32 i;
+       struct yaffs_dev *dev;
+       struct yaffs_ext_tags tags;
+       struct yaffs_tnode *tn;
+       u32 obj_id;
+
+       if (!obj)
+               return;
+
+       if (yaffs_skip_verification(obj->my_dev))
+               return;
+
+       dev = obj->my_dev;
+       obj_id = obj->obj_id;
+
+       /* Check file size is consistent with tnode depth */
+       last_chunk =
+           obj->variant.file_variant.file_size / dev->data_bytes_per_chunk + 1;
+       x = last_chunk >> YAFFS_TNODES_LEVEL0_BITS;
+       required_depth = 0;
+       while (x > 0) {
+               x >>= YAFFS_TNODES_INTERNAL_BITS;
+               required_depth++;
+       }
+
+       actual_depth = obj->variant.file_variant.top_level;
+
+       /* Check that the chunks in the tnode tree are all correct.
+        * We do this by scanning through the tnode tree and
+        * checking the tags for every chunk match.
+        */
+
+       if (yaffs_skip_nand_verification(dev))
+               return;
+
+       for (i = 1; i <= last_chunk; i++) {
+               tn = yaffs_find_tnode_0(dev, &obj->variant.file_variant, i);
+
+               if (tn) {
+                       u32 the_chunk = yaffs_get_group_base(dev, tn, i);
+                       if (the_chunk > 0) {
+                               yaffs_rd_chunk_tags_nand(dev, the_chunk, NULL,
+                                                        &tags);
+                               if (tags.obj_id != obj_id || tags.chunk_id != i)
+                               yaffs_trace(YAFFS_TRACE_VERIFY,
+                                       "Object %d chunk_id %d NAND mismatch chunk %d tags (%d:%d)",
+                                        obj_id, i, the_chunk,
+                                        tags.obj_id, tags.chunk_id);
+                       }
+               }
+       }
+}
+
+void yaffs_verify_link(struct yaffs_obj *obj)
+{
+       if (obj && yaffs_skip_verification(obj->my_dev))
+               return;
+
+       /* Verify sane equivalent object */
+}
+
+void yaffs_verify_symlink(struct yaffs_obj *obj)
+{
+       if (obj && yaffs_skip_verification(obj->my_dev))
+               return;
+
+       /* Verify symlink string */
+}
+
+void yaffs_verify_special(struct yaffs_obj *obj)
+{
+       if (obj && yaffs_skip_verification(obj->my_dev))
+               return;
+}
+
+void yaffs_verify_obj(struct yaffs_obj *obj)
+{
+       struct yaffs_dev *dev;
+
+       u32 chunk_min;
+       u32 chunk_max;
+
+       u32 chunk_id_ok;
+       u32 chunk_in_range;
+       u32 chunk_wrongly_deleted;
+       u32 chunk_valid;
+
+       if (!obj)
+               return;
+
+       if (obj->being_created)
+               return;
+
+       dev = obj->my_dev;
+
+       if (yaffs_skip_verification(dev))
+               return;
+
+       /* Check sane object header chunk */
+
+       chunk_min = dev->internal_start_block * dev->param.chunks_per_block;
+       chunk_max =
+           (dev->internal_end_block + 1) * dev->param.chunks_per_block - 1;
+
+       chunk_in_range = (((unsigned)(obj->hdr_chunk)) >= chunk_min &&
+                         ((unsigned)(obj->hdr_chunk)) <= chunk_max);
+       chunk_id_ok = chunk_in_range || (obj->hdr_chunk == 0);
+       chunk_valid = chunk_in_range &&
+           yaffs_check_chunk_bit(dev,
+                                 obj->hdr_chunk / dev->param.chunks_per_block,
+                                 obj->hdr_chunk % dev->param.chunks_per_block);
+       chunk_wrongly_deleted = chunk_in_range && !chunk_valid;
+
+       if (!obj->fake && (!chunk_id_ok || chunk_wrongly_deleted))
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Obj %d has chunk_id %d %s %s",
+                       obj->obj_id, obj->hdr_chunk,
+                       chunk_id_ok ? "" : ",out of range",
+                       chunk_wrongly_deleted ? ",marked as deleted" : "");
+
+       if (chunk_valid && !yaffs_skip_nand_verification(dev)) {
+               struct yaffs_ext_tags tags;
+               struct yaffs_obj_hdr *oh;
+               u8 *buffer = yaffs_get_temp_buffer(dev, __LINE__);
+
+               oh = (struct yaffs_obj_hdr *)buffer;
+
+               yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, buffer, &tags);
+
+               yaffs_verify_oh(obj, oh, &tags, 1);
+
+               yaffs_release_temp_buffer(dev, buffer, __LINE__);
+       }
+
+       /* Verify it has a parent */
+       if (obj && !obj->fake && (!obj->parent || obj->parent->my_dev != dev)) {
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Obj %d has parent pointer %p which does not look like an object",
+                       obj->obj_id, obj->parent);
+       }
+
+       /* Verify parent is a directory */
+       if (obj->parent
+           && obj->parent->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Obj %d's parent is not a directory (type %d)",
+                       obj->obj_id, obj->parent->variant_type);
+       }
+
+       switch (obj->variant_type) {
+       case YAFFS_OBJECT_TYPE_FILE:
+               yaffs_verify_file(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_SYMLINK:
+               yaffs_verify_symlink(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_DIRECTORY:
+               yaffs_verify_dir(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_HARDLINK:
+               yaffs_verify_link(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_SPECIAL:
+               yaffs_verify_special(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_UNKNOWN:
+       default:
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Obj %d has illegaltype %d",
+                  obj->obj_id, obj->variant_type);
+               break;
+       }
+}
+
+void yaffs_verify_objects(struct yaffs_dev *dev)
+{
+       struct yaffs_obj *obj;
+       int i;
+       struct list_head *lh;
+
+       if (yaffs_skip_verification(dev))
+               return;
+
+       /* Iterate through the objects in each hash entry */
+
+       for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
+               list_for_each(lh, &dev->obj_bucket[i].list) {
+                       if (lh) {
+                               obj =
+                                   list_entry(lh, struct yaffs_obj, hash_link);
+                               yaffs_verify_obj(obj);
+                       }
+               }
+       }
+}
+
+void yaffs_verify_obj_in_dir(struct yaffs_obj *obj)
+{
+       struct list_head *lh;
+       struct yaffs_obj *list_obj;
+
+       int count = 0;
+
+       if (!obj) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS, "No object to verify");
+               YBUG();
+               return;
+       }
+
+       if (yaffs_skip_verification(obj->my_dev))
+               return;
+
+       if (!obj->parent) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS, "Object does not have parent" );
+               YBUG();
+               return;
+       }
+
+       if (obj->parent->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS, "Parent is not directory");
+               YBUG();
+       }
+
+       /* Iterate through the objects in each hash entry */
+
+       list_for_each(lh, &obj->parent->variant.dir_variant.children) {
+               if (lh) {
+                       list_obj = list_entry(lh, struct yaffs_obj, siblings);
+                       yaffs_verify_obj(list_obj);
+                       if (obj == list_obj)
+                               count++;
+               }
+       }
+
+       if (count != 1) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "Object in directory %d times",
+                       count);
+               YBUG();
+       }
+}
+
+void yaffs_verify_dir(struct yaffs_obj *directory)
+{
+       struct list_head *lh;
+       struct yaffs_obj *list_obj;
+
+       if (!directory) {
+               YBUG();
+               return;
+       }
+
+       if (yaffs_skip_full_verification(directory->my_dev))
+               return;
+
+       if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "Directory has wrong type: %d",
+                       directory->variant_type);
+               YBUG();
+       }
+
+       /* Iterate through the objects in each hash entry */
+
+       list_for_each(lh, &directory->variant.dir_variant.children) {
+               if (lh) {
+                       list_obj = list_entry(lh, struct yaffs_obj, siblings);
+                       if (list_obj->parent != directory) {
+                               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                                       "Object in directory list has wrong parent %p",
+                                       list_obj->parent);
+                               YBUG();
+                       }
+                       yaffs_verify_obj_in_dir(list_obj);
+               }
+       }
+}
+
+static int yaffs_free_verification_failures;
+
+void yaffs_verify_free_chunks(struct yaffs_dev *dev)
+{
+       int counted;
+       int difference;
+
+       if (yaffs_skip_verification(dev))
+               return;
+
+       counted = yaffs_count_free_chunks(dev);
+
+       difference = dev->n_free_chunks - counted;
+
+       if (difference) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "Freechunks verification failure %d %d %d",
+                       dev->n_free_chunks, counted, difference);
+               yaffs_free_verification_failures++;
+       }
+}
+
+int yaffs_verify_file_sane(struct yaffs_obj *in)
+{
+       in = in;
+       return YAFFS_OK;
+}
+
diff --git a/fs/yaffs2/yaffs_verify.h b/fs/yaffs2/yaffs_verify.h
new file mode 100644 (file)
index 0000000..cc6f889
--- /dev/null
@@ -0,0 +1,43 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_VERIFY_H__
+#define __YAFFS_VERIFY_H__
+
+#include "yaffs_guts.h"
+
+void yaffs_verify_blk(struct yaffs_dev *dev, struct yaffs_block_info *bi,
+                     int n);
+void yaffs_verify_collected_blk(struct yaffs_dev *dev,
+                               struct yaffs_block_info *bi, int n);
+void yaffs_verify_blocks(struct yaffs_dev *dev);
+
+void yaffs_verify_oh(struct yaffs_obj *obj, struct yaffs_obj_hdr *oh,
+                    struct yaffs_ext_tags *tags, int parent_check);
+void yaffs_verify_file(struct yaffs_obj *obj);
+void yaffs_verify_link(struct yaffs_obj *obj);
+void yaffs_verify_symlink(struct yaffs_obj *obj);
+void yaffs_verify_special(struct yaffs_obj *obj);
+void yaffs_verify_obj(struct yaffs_obj *obj);
+void yaffs_verify_objects(struct yaffs_dev *dev);
+void yaffs_verify_obj_in_dir(struct yaffs_obj *obj);
+void yaffs_verify_dir(struct yaffs_obj *directory);
+void yaffs_verify_free_chunks(struct yaffs_dev *dev);
+
+int yaffs_verify_file_sane(struct yaffs_obj *obj);
+
+int yaffs_skip_verification(struct yaffs_dev *dev);
+
+#endif
diff --git a/fs/yaffs2/yaffs_vfs.c b/fs/yaffs2/yaffs_vfs.c
new file mode 100644 (file)
index 0000000..d5b8753
--- /dev/null
@@ -0,0 +1,2792 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ * Acknowledgements:
+ * Luc van OostenRyck for numerous patches.
+ * Nick Bane for numerous patches.
+ * Nick Bane for 2.5/2.6 integration.
+ * Andras Toth for mknod rdev issue.
+ * Michael Fischer for finding the problem with inode inconsistency.
+ * Some code bodily lifted from JFFS
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ *
+ * This is the file system front-end to YAFFS that hooks it up to
+ * the VFS.
+ *
+ * Special notes:
+ * >> 2.4: sb->u.generic_sbp points to the struct yaffs_dev associated with
+ *         this superblock
+ * >> 2.6: sb->s_fs_info  points to the struct yaffs_dev associated with this
+ *         superblock
+ * >> inode->u.generic_ip points to the associated struct yaffs_obj.
+ */
+
+/*
+ * NB There are two variants of Linux VFS glue code. This variant supports
+ * a single version and should not include any multi-version code.
+ */
+#include <linux/version.h>
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/proc_fs.h>
+#include <linux/smp_lock.h>
+#include <linux/pagemap.h>
+#include <linux/mtd/mtd.h>
+#include <linux/interrupt.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/namei.h>
+#include <linux/exportfs.h>
+#include <linux/kthread.h>
+#include <linux/delay.h>
+#include <linux/freezer.h>
+
+#include <asm/div64.h>
+
+#include <linux/statfs.h>
+
+#define UnlockPage(p) unlock_page(p)
+#define Page_Uptodate(page)    test_bit(PG_uptodate, &(page)->flags)
+
+#define yaffs_devname(sb, buf) bdevname(sb->s_bdev, buf)
+
+#define YPROC_ROOT  NULL
+
+#define Y_INIT_TIMER(a)        init_timer_on_stack(a)
+
+#define WRITE_SIZE_STR "writesize"
+#define WRITE_SIZE(mtd) ((mtd)->writesize)
+
+static uint32_t YCALCBLOCKS(uint64_t partition_size, uint32_t block_size)
+{
+       uint64_t result = partition_size;
+       do_div(result, block_size);
+       return (uint32_t) result;
+}
+
+#include <linux/uaccess.h>
+#include <linux/mtd/mtd.h>
+
+#include "yportenv.h"
+#include "yaffs_trace.h"
+#include "yaffs_guts.h"
+#include "yaffs_attribs.h"
+
+#include "yaffs_linux.h"
+
+#include "yaffs_mtdif.h"
+#include "yaffs_mtdif1.h"
+#include "yaffs_mtdif2.h"
+
+unsigned int yaffs_trace_mask = YAFFS_TRACE_BAD_BLOCKS | YAFFS_TRACE_ALWAYS;
+unsigned int yaffs_wr_attempts = YAFFS_WR_ATTEMPTS;
+unsigned int yaffs_auto_checkpoint = 1;
+unsigned int yaffs_gc_control = 1;
+unsigned int yaffs_bg_enable = 1;
+
+/* Module Parameters */
+module_param(yaffs_trace_mask, uint, 0644);
+module_param(yaffs_wr_attempts, uint, 0644);
+module_param(yaffs_auto_checkpoint, uint, 0644);
+module_param(yaffs_gc_control, uint, 0644);
+module_param(yaffs_bg_enable, uint, 0644);
+
+
+#define yaffs_inode_to_obj_lv(iptr) ((iptr)->i_private)
+#define yaffs_inode_to_obj(iptr) ((struct yaffs_obj *)(yaffs_inode_to_obj_lv(iptr)))
+#define yaffs_dentry_to_obj(dptr) yaffs_inode_to_obj((dptr)->d_inode)
+#define yaffs_super_to_dev(sb) ((struct yaffs_dev *)sb->s_fs_info)
+
+#define update_dir_time(dir) do {\
+                       (dir)->i_ctime = (dir)->i_mtime = CURRENT_TIME; \
+               } while(0)
+
+
+static unsigned yaffs_gc_control_callback(struct yaffs_dev *dev)
+{
+       return yaffs_gc_control;
+}
+
+static void yaffs_gross_lock(struct yaffs_dev *dev)
+{
+       yaffs_trace(YAFFS_TRACE_LOCK, "yaffs locking %p", current);
+       mutex_lock(&(yaffs_dev_to_lc(dev)->gross_lock));
+       yaffs_trace(YAFFS_TRACE_LOCK, "yaffs locked %p", current);
+}
+
+static void yaffs_gross_unlock(struct yaffs_dev *dev)
+{
+       yaffs_trace(YAFFS_TRACE_LOCK, "yaffs unlocking %p", current);
+       mutex_unlock(&(yaffs_dev_to_lc(dev)->gross_lock));
+}
+
+static void yaffs_fill_inode_from_obj(struct inode *inode,
+                                     struct yaffs_obj *obj);
+
+static struct inode *yaffs_iget(struct super_block *sb, unsigned long ino)
+{
+       struct inode *inode;
+       struct yaffs_obj *obj;
+       struct yaffs_dev *dev = yaffs_super_to_dev(sb);
+
+       yaffs_trace(YAFFS_TRACE_OS, "yaffs_iget for %lu", ino);
+
+       inode = iget_locked(sb, ino);
+       if (!inode)
+               return ERR_PTR(-ENOMEM);
+       if (!(inode->i_state & I_NEW))
+               return inode;
+
+       /* NB This is called as a side effect of other functions, but
+        * we had to release the lock to prevent deadlocks, so
+        * need to lock again.
+        */
+
+       yaffs_gross_lock(dev);
+
+       obj = yaffs_find_by_number(dev, inode->i_ino);
+
+       yaffs_fill_inode_from_obj(inode, obj);
+
+       yaffs_gross_unlock(dev);
+
+       unlock_new_inode(inode);
+       return inode;
+}
+
+struct inode *yaffs_get_inode(struct super_block *sb, int mode, int dev,
+                             struct yaffs_obj *obj)
+{
+       struct inode *inode;
+
+       if (!sb) {
+               yaffs_trace(YAFFS_TRACE_OS,
+                       "yaffs_get_inode for NULL super_block!!");
+               return NULL;
+
+       }
+
+       if (!obj) {
+               yaffs_trace(YAFFS_TRACE_OS,
+                       "yaffs_get_inode for NULL object!!");
+               return NULL;
+
+       }
+
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_get_inode for object %d",
+               obj->obj_id);
+
+       inode = yaffs_iget(sb, obj->obj_id);
+       if (IS_ERR(inode))
+               return NULL;
+
+       /* NB Side effect: iget calls back to yaffs_read_inode(). */
+       /* iget also increments the inode's i_count */
+       /* NB You can't be holding gross_lock or deadlock will happen! */
+
+       return inode;
+}
+
+static int yaffs_mknod(struct inode *dir, struct dentry *dentry, int mode,
+                      dev_t rdev)
+{
+       struct inode *inode;
+
+       struct yaffs_obj *obj = NULL;
+       struct yaffs_dev *dev;
+
+       struct yaffs_obj *parent = yaffs_inode_to_obj(dir);
+
+       int error = -ENOSPC;
+       uid_t uid = current->cred->fsuid;
+       gid_t gid =
+           (dir->i_mode & S_ISGID) ? dir->i_gid : current->cred->fsgid;
+
+       if ((dir->i_mode & S_ISGID) && S_ISDIR(mode))
+               mode |= S_ISGID;
+
+       if (parent) {
+               yaffs_trace(YAFFS_TRACE_OS,
+                       "yaffs_mknod: parent object %d type %d",
+                       parent->obj_id, parent->variant_type);
+       } else {
+               yaffs_trace(YAFFS_TRACE_OS,
+                       "yaffs_mknod: could not get parent object");
+               return -EPERM;
+       }
+
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_mknod: making oject for %s, mode %x dev %x",
+               dentry->d_name.name, mode, rdev);
+
+       dev = parent->my_dev;
+
+       yaffs_gross_lock(dev);
+
+       switch (mode & S_IFMT) {
+       default:
+               /* Special (socket, fifo, device...) */
+               yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod: making special");
+               obj =
+                   yaffs_create_special(parent, dentry->d_name.name, mode, uid,
+                                        gid, old_encode_dev(rdev));
+               break;
+       case S_IFREG:           /* file          */
+               yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod: making file");
+               obj = yaffs_create_file(parent, dentry->d_name.name, mode, uid,
+                                       gid);
+               break;
+       case S_IFDIR:           /* directory */
+               yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod: making directory");
+               obj = yaffs_create_dir(parent, dentry->d_name.name, mode,
+                                      uid, gid);
+               break;
+       case S_IFLNK:           /* symlink */
+               yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod: making symlink");
+               obj = NULL;     /* Do we ever get here? */
+               break;
+       }
+
+       /* Can not call yaffs_get_inode() with gross lock held */
+       yaffs_gross_unlock(dev);
+
+       if (obj) {
+               inode = yaffs_get_inode(dir->i_sb, mode, rdev, obj);
+               d_instantiate(dentry, inode);
+               update_dir_time(dir);
+               yaffs_trace(YAFFS_TRACE_OS,
+                       "yaffs_mknod created object %d count = %d",
+                       obj->obj_id, atomic_read(&inode->i_count));
+               error = 0;
+               yaffs_fill_inode_from_obj(dir, parent);
+       } else {
+               yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod failed making object");
+               error = -ENOMEM;
+       }
+
+       return error;
+}
+
+static int yaffs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+       return yaffs_mknod(dir, dentry, mode | S_IFDIR, 0);
+}
+
+static int yaffs_create(struct inode *dir, struct dentry *dentry, int mode,
+                       struct nameidata *n)
+{
+       return yaffs_mknod(dir, dentry, mode | S_IFREG, 0);
+}
+
+static int yaffs_link(struct dentry *old_dentry, struct inode *dir,
+                     struct dentry *dentry)
+{
+       struct inode *inode = old_dentry->d_inode;
+       struct yaffs_obj *obj = NULL;
+       struct yaffs_obj *link = NULL;
+       struct yaffs_dev *dev;
+
+       yaffs_trace(YAFFS_TRACE_OS, "yaffs_link");
+
+       obj = yaffs_inode_to_obj(inode);
+       dev = obj->my_dev;
+
+       yaffs_gross_lock(dev);
+
+       if (!S_ISDIR(inode->i_mode))    /* Don't link directories */
+               link =
+                   yaffs_link_obj(yaffs_inode_to_obj(dir), dentry->d_name.name,
+                                  obj);
+
+       if (link) {
+               old_dentry->d_inode->i_nlink = yaffs_get_obj_link_count(obj);
+               d_instantiate(dentry, old_dentry->d_inode);
+               atomic_inc(&old_dentry->d_inode->i_count);
+               yaffs_trace(YAFFS_TRACE_OS,
+                       "yaffs_link link count %d i_count %d",
+                       old_dentry->d_inode->i_nlink,
+                       atomic_read(&old_dentry->d_inode->i_count));
+       }
+
+       yaffs_gross_unlock(dev);
+
+       if (link) {
+               update_dir_time(dir);
+               return 0;
+       }
+
+       return -EPERM;
+}
+
+static int yaffs_symlink(struct inode *dir, struct dentry *dentry,
+                        const char *symname)
+{
+       struct yaffs_obj *obj;
+       struct yaffs_dev *dev;
+       uid_t uid = current->cred->fsuid;
+       gid_t gid =
+           (dir->i_mode & S_ISGID) ? dir->i_gid : current->cred->fsgid;
+
+       yaffs_trace(YAFFS_TRACE_OS, "yaffs_symlink");
+
+       dev = yaffs_inode_to_obj(dir)->my_dev;
+       yaffs_gross_lock(dev);
+       obj = yaffs_create_symlink(yaffs_inode_to_obj(dir), dentry->d_name.name,
+                                  S_IFLNK | S_IRWXUGO, uid, gid, symname);
+       yaffs_gross_unlock(dev);
+
+       if (obj) {
+               struct inode *inode;
+
+               inode = yaffs_get_inode(dir->i_sb, obj->yst_mode, 0, obj);
+               d_instantiate(dentry, inode);
+               update_dir_time(dir);
+               yaffs_trace(YAFFS_TRACE_OS, "symlink created OK");
+               return 0;
+       } else {
+               yaffs_trace(YAFFS_TRACE_OS, "symlink not created");
+       }
+
+       return -ENOMEM;
+}
+
+static struct dentry *yaffs_lookup(struct inode *dir, struct dentry *dentry,
+                                  struct nameidata *n)
+{
+       struct yaffs_obj *obj;
+       struct inode *inode = NULL;
+
+       struct yaffs_dev *dev = yaffs_inode_to_obj(dir)->my_dev;
+
+       if (current != yaffs_dev_to_lc(dev)->readdir_process)
+               yaffs_gross_lock(dev);
+
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_lookup for %d:%s",
+               yaffs_inode_to_obj(dir)->obj_id, dentry->d_name.name);
+
+       obj = yaffs_find_by_name(yaffs_inode_to_obj(dir), dentry->d_name.name);
+
+       obj = yaffs_get_equivalent_obj(obj);    /* in case it was a hardlink */
+
+       /* Can't hold gross lock when calling yaffs_get_inode() */
+       if (current != yaffs_dev_to_lc(dev)->readdir_process)
+               yaffs_gross_unlock(dev);
+
+       if (obj) {
+               yaffs_trace(YAFFS_TRACE_OS,
+                       "yaffs_lookup found %d", obj->obj_id);
+
+               inode = yaffs_get_inode(dir->i_sb, obj->yst_mode, 0, obj);
+
+               if (inode) {
+                       yaffs_trace(YAFFS_TRACE_OS, "yaffs_loookup dentry");
+                       d_add(dentry, inode);
+                       /* return dentry; */
+                       return NULL;
+               }
+
+       } else {
+               yaffs_trace(YAFFS_TRACE_OS, "yaffs_lookup not found");
+
+       }
+
+       d_add(dentry, inode);
+
+       return NULL;
+}
+
+static int yaffs_unlink(struct inode *dir, struct dentry *dentry)
+{
+       int ret_val;
+
+       struct yaffs_dev *dev;
+       struct yaffs_obj *obj;
+
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_unlink %d:%s",
+               (int)(dir->i_ino), dentry->d_name.name);
+       obj = yaffs_inode_to_obj(dir);
+       dev = obj->my_dev;
+
+       yaffs_gross_lock(dev);
+
+       ret_val = yaffs_unlinker(obj, dentry->d_name.name);
+
+       if (ret_val == YAFFS_OK) {
+               dentry->d_inode->i_nlink--;
+               dir->i_version++;
+               yaffs_gross_unlock(dev);
+               mark_inode_dirty(dentry->d_inode);
+               update_dir_time(dir);
+               return 0;
+       }
+       yaffs_gross_unlock(dev);
+       return -ENOTEMPTY;
+}
+
+static int yaffs_sync_object(struct file *file, int datasync)
+{
+
+       struct yaffs_obj *obj;
+       struct yaffs_dev *dev;
+       struct dentry *dentry = file->f_path.dentry;
+
+       obj = yaffs_dentry_to_obj(dentry);
+
+       dev = obj->my_dev;
+
+       yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC, "yaffs_sync_object");
+       yaffs_gross_lock(dev);
+       yaffs_flush_file(obj, 1, datasync);
+       yaffs_gross_unlock(dev);
+       return 0;
+}
+/*
+ * The VFS layer already does all the dentry stuff for rename.
+ *
+ * NB: POSIX says you can rename an object over an old object of the same name
+ */
+static int yaffs_rename(struct inode *old_dir, struct dentry *old_dentry,
+                       struct inode *new_dir, struct dentry *new_dentry)
+{
+       struct yaffs_dev *dev;
+       int ret_val = YAFFS_FAIL;
+       struct yaffs_obj *target;
+
+       yaffs_trace(YAFFS_TRACE_OS, "yaffs_rename");
+       dev = yaffs_inode_to_obj(old_dir)->my_dev;
+
+       yaffs_gross_lock(dev);
+
+       /* Check if the target is an existing directory that is not empty. */
+       target = yaffs_find_by_name(yaffs_inode_to_obj(new_dir),
+                                   new_dentry->d_name.name);
+
+       if (target && target->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY &&
+           !list_empty(&target->variant.dir_variant.children)) {
+
+               yaffs_trace(YAFFS_TRACE_OS, "target is non-empty dir");
+
+               ret_val = YAFFS_FAIL;
+       } else {
+               /* Now does unlinking internally using shadowing mechanism */
+               yaffs_trace(YAFFS_TRACE_OS, "calling yaffs_rename_obj");
+
+               ret_val = yaffs_rename_obj(yaffs_inode_to_obj(old_dir),
+                                          old_dentry->d_name.name,
+                                          yaffs_inode_to_obj(new_dir),
+                                          new_dentry->d_name.name);
+       }
+       yaffs_gross_unlock(dev);
+
+       if (ret_val == YAFFS_OK) {
+               if (target) {
+                       new_dentry->d_inode->i_nlink--;
+                       mark_inode_dirty(new_dentry->d_inode);
+               }
+
+               update_dir_time(old_dir);
+               if (old_dir != new_dir)
+                       update_dir_time(new_dir);
+               return 0;
+       } else {
+               return -ENOTEMPTY;
+       }
+}
+
+static int yaffs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+       struct inode *inode = dentry->d_inode;
+       int error = 0;
+       struct yaffs_dev *dev;
+
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_setattr of object %d",
+               yaffs_inode_to_obj(inode)->obj_id);
+
+       /* Fail if a requested resize >= 2GB */
+       if (attr->ia_valid & ATTR_SIZE && (attr->ia_size >> 31))
+               error = -EINVAL;
+
+       if (error == 0)
+               error = inode_change_ok(inode, attr);
+       if (error == 0) {
+               int result;
+               if (!error) {
+                       setattr_copy(inode, attr);
+                       yaffs_trace(YAFFS_TRACE_OS, "inode_setattr called");
+                       if (attr->ia_valid & ATTR_SIZE) {
+                               truncate_setsize(inode, attr->ia_size);
+                               inode->i_blocks = (inode->i_size + 511) >> 9;
+                       }
+               }
+               dev = yaffs_inode_to_obj(inode)->my_dev;
+               if (attr->ia_valid & ATTR_SIZE) {
+                       yaffs_trace(YAFFS_TRACE_OS, "resize to %d(%x)",
+                                          (int)(attr->ia_size),
+                                          (int)(attr->ia_size));
+               }
+               yaffs_gross_lock(dev);
+               result = yaffs_set_attribs(yaffs_inode_to_obj(inode), attr);
+               if (result == YAFFS_OK) {
+                       error = 0;
+               } else {
+                       error = -EPERM;
+               }
+               yaffs_gross_unlock(dev);
+
+       }
+
+       yaffs_trace(YAFFS_TRACE_OS, "yaffs_setattr done returning %d", error);
+
+       return error;
+}
+
+#ifdef CONFIG_YAFFS_XATTR
+static int yaffs_setxattr(struct dentry *dentry, const char *name,
+                  const void *value, size_t size, int flags)
+{
+       struct inode *inode = dentry->d_inode;
+       int error = 0;
+       struct yaffs_dev *dev;
+       struct yaffs_obj *obj = yaffs_inode_to_obj(inode);
+
+       yaffs_trace(YAFFS_TRACE_OS, "yaffs_setxattr of object %d", obj->obj_id);
+
+       if (error == 0) {
+               int result;
+               dev = obj->my_dev;
+               yaffs_gross_lock(dev);
+               result = yaffs_set_xattrib(obj, name, value, size, flags);
+               if (result == YAFFS_OK)
+                       error = 0;
+               else if (result < 0)
+                       error = result;
+               yaffs_gross_unlock(dev);
+
+       }
+       yaffs_trace(YAFFS_TRACE_OS, "yaffs_setxattr done returning %d", error);
+
+       return error;
+}
+
+static ssize_t yaffs_getxattr(struct dentry * dentry, const char *name, void *buff,
+                      size_t size)
+{
+       struct inode *inode = dentry->d_inode;
+       int error = 0;
+       struct yaffs_dev *dev;
+       struct yaffs_obj *obj = yaffs_inode_to_obj(inode);
+
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_getxattr \"%s\" from object %d",
+               name, obj->obj_id);
+
+       if (error == 0) {
+               dev = obj->my_dev;
+               yaffs_gross_lock(dev);
+               error = yaffs_get_xattrib(obj, name, buff, size);
+               yaffs_gross_unlock(dev);
+
+       }
+       yaffs_trace(YAFFS_TRACE_OS, "yaffs_getxattr done returning %d", error);
+
+       return error;
+}
+
+static int yaffs_removexattr(struct dentry *dentry, const char *name)
+{
+       struct inode *inode = dentry->d_inode;
+       int error = 0;
+       struct yaffs_dev *dev;
+       struct yaffs_obj *obj = yaffs_inode_to_obj(inode);
+
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_removexattr of object %d", obj->obj_id);
+
+       if (error == 0) {
+               int result;
+               dev = obj->my_dev;
+               yaffs_gross_lock(dev);
+               result = yaffs_remove_xattrib(obj, name);
+               if (result == YAFFS_OK)
+                       error = 0;
+               else if (result < 0)
+                       error = result;
+               yaffs_gross_unlock(dev);
+
+       }
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_removexattr done returning %d", error);
+
+       return error;
+}
+
+static ssize_t yaffs_listxattr(struct dentry * dentry, char *buff, size_t size)
+{
+       struct inode *inode = dentry->d_inode;
+       int error = 0;
+       struct yaffs_dev *dev;
+       struct yaffs_obj *obj = yaffs_inode_to_obj(inode);
+
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_listxattr of object %d", obj->obj_id);
+
+       if (error == 0) {
+               dev = obj->my_dev;
+               yaffs_gross_lock(dev);
+               error = yaffs_list_xattrib(obj, buff, size);
+               yaffs_gross_unlock(dev);
+
+       }
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_listxattr done returning %d", error);
+
+       return error;
+}
+
+#endif
+
+static const struct inode_operations yaffs_dir_inode_operations = {
+       .create = yaffs_create,
+       .lookup = yaffs_lookup,
+       .link = yaffs_link,
+       .unlink = yaffs_unlink,
+       .symlink = yaffs_symlink,
+       .mkdir = yaffs_mkdir,
+       .rmdir = yaffs_unlink,
+       .mknod = yaffs_mknod,
+       .rename = yaffs_rename,
+       .setattr = yaffs_setattr,
+#ifdef CONFIG_YAFFS_XATTR
+       .setxattr = yaffs_setxattr,
+       .getxattr = yaffs_getxattr,
+       .listxattr = yaffs_listxattr,
+       .removexattr = yaffs_removexattr,
+#endif
+};
+/*-----------------------------------------------------------------*/
+/* Directory search context allows us to unlock access to yaffs during
+ * filldir without causing problems with the directory being modified.
+ * This is similar to the tried and tested mechanism used in yaffs direct.
+ *
+ * A search context iterates along a doubly linked list of siblings in the
+ * directory. If the iterating object is deleted then this would corrupt
+ * the list iteration, likely causing a crash. The search context avoids
+ * this by using the remove_obj_fn to move the search context to the
+ * next object before the object is deleted.
+ *
+ * Many readdirs (and thus seach conexts) may be alive simulateously so
+ * each struct yaffs_dev has a list of these.
+ *
+ * A seach context lives for the duration of a readdir.
+ *
+ * All these functions must be called while yaffs is locked.
+ */
+
+struct yaffs_search_context {
+       struct yaffs_dev *dev;
+       struct yaffs_obj *dir_obj;
+       struct yaffs_obj *next_return;
+       struct list_head others;
+};
+
+/*
+ * yaffs_new_search() creates a new search context, initialises it and
+ * adds it to the device's search context list.
+ *
+ * Called at start of readdir.
+ */
+static struct yaffs_search_context *yaffs_new_search(struct yaffs_obj *dir)
+{
+       struct yaffs_dev *dev = dir->my_dev;
+       struct yaffs_search_context *sc =
+           kmalloc(sizeof(struct yaffs_search_context), GFP_NOFS);
+       if (sc) {
+               sc->dir_obj = dir;
+               sc->dev = dev;
+               if (list_empty(&sc->dir_obj->variant.dir_variant.children))
+                       sc->next_return = NULL;
+               else
+                       sc->next_return =
+                           list_entry(dir->variant.dir_variant.children.next,
+                                      struct yaffs_obj, siblings);
+               INIT_LIST_HEAD(&sc->others);
+               list_add(&sc->others, &(yaffs_dev_to_lc(dev)->search_contexts));
+       }
+       return sc;
+}
+
+/*
+ * yaffs_search_end() disposes of a search context and cleans up.
+ */
+static void yaffs_search_end(struct yaffs_search_context *sc)
+{
+       if (sc) {
+               list_del(&sc->others);
+               kfree(sc);
+       }
+}
+
+/*
+ * yaffs_search_advance() moves a search context to the next object.
+ * Called when the search iterates or when an object removal causes
+ * the search context to be moved to the next object.
+ */
+static void yaffs_search_advance(struct yaffs_search_context *sc)
+{
+       if (!sc)
+               return;
+
+       if (sc->next_return == NULL ||
+           list_empty(&sc->dir_obj->variant.dir_variant.children))
+               sc->next_return = NULL;
+       else {
+               struct list_head *next = sc->next_return->siblings.next;
+
+               if (next == &sc->dir_obj->variant.dir_variant.children)
+                       sc->next_return = NULL; /* end of list */
+               else
+                       sc->next_return =
+                           list_entry(next, struct yaffs_obj, siblings);
+       }
+}
+
+/*
+ * yaffs_remove_obj_callback() is called when an object is unlinked.
+ * We check open search contexts and advance any which are currently
+ * on the object being iterated.
+ */
+static void yaffs_remove_obj_callback(struct yaffs_obj *obj)
+{
+
+       struct list_head *i;
+       struct yaffs_search_context *sc;
+       struct list_head *search_contexts =
+           &(yaffs_dev_to_lc(obj->my_dev)->search_contexts);
+
+       /* Iterate through the directory search contexts.
+        * If any are currently on the object being removed, then advance
+        * the search context to the next object to prevent a hanging pointer.
+        */
+       list_for_each(i, search_contexts) {
+               if (i) {
+                       sc = list_entry(i, struct yaffs_search_context, others);
+                       if (sc->next_return == obj)
+                               yaffs_search_advance(sc);
+               }
+       }
+
+}
+
+static int yaffs_readdir(struct file *f, void *dirent, filldir_t filldir)
+{
+       struct yaffs_obj *obj;
+       struct yaffs_dev *dev;
+       struct yaffs_search_context *sc;
+       struct inode *inode = f->f_dentry->d_inode;
+       unsigned long offset, curoffs;
+       struct yaffs_obj *l;
+       int ret_val = 0;
+
+       char name[YAFFS_MAX_NAME_LENGTH + 1];
+
+       obj = yaffs_dentry_to_obj(f->f_dentry);
+       dev = obj->my_dev;
+
+       yaffs_gross_lock(dev);
+
+       yaffs_dev_to_lc(dev)->readdir_process = current;
+
+       offset = f->f_pos;
+
+       sc = yaffs_new_search(obj);
+       if (!sc) {
+               ret_val = -ENOMEM;
+               goto out;
+       }
+
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_readdir: starting at %d", (int)offset);
+
+       if (offset == 0) {
+               yaffs_trace(YAFFS_TRACE_OS,
+                       "yaffs_readdir: entry . ino %d",
+                       (int)inode->i_ino);
+               yaffs_gross_unlock(dev);
+               if (filldir(dirent, ".", 1, offset, inode->i_ino, DT_DIR) < 0) {
+                       yaffs_gross_lock(dev);
+                       goto out;
+               }
+               yaffs_gross_lock(dev);
+               offset++;
+               f->f_pos++;
+       }
+       if (offset == 1) {
+               yaffs_trace(YAFFS_TRACE_OS,
+                       "yaffs_readdir: entry .. ino %d",
+                       (int)f->f_dentry->d_parent->d_inode->i_ino);
+               yaffs_gross_unlock(dev);
+               if (filldir(dirent, "..", 2, offset,
+                           f->f_dentry->d_parent->d_inode->i_ino,
+                           DT_DIR) < 0) {
+                       yaffs_gross_lock(dev);
+                       goto out;
+               }
+               yaffs_gross_lock(dev);
+               offset++;
+               f->f_pos++;
+       }
+
+       curoffs = 1;
+
+       /* If the directory has changed since the open or last call to
+          readdir, rewind to after the 2 canned entries. */
+       if (f->f_version != inode->i_version) {
+               offset = 2;
+               f->f_pos = offset;
+               f->f_version = inode->i_version;
+       }
+
+       while (sc->next_return) {
+               curoffs++;
+               l = sc->next_return;
+               if (curoffs >= offset) {
+                       int this_inode = yaffs_get_obj_inode(l);
+                       int this_type = yaffs_get_obj_type(l);
+
+                       yaffs_get_obj_name(l, name, YAFFS_MAX_NAME_LENGTH + 1);
+                       yaffs_trace(YAFFS_TRACE_OS,
+                               "yaffs_readdir: %s inode %d",
+                               name, yaffs_get_obj_inode(l));
+
+                       yaffs_gross_unlock(dev);
+
+                       if (filldir(dirent,
+                                   name,
+                                   strlen(name),
+                                   offset, this_inode, this_type) < 0) {
+                               yaffs_gross_lock(dev);
+                               goto out;
+                       }
+
+                       yaffs_gross_lock(dev);
+
+                       offset++;
+                       f->f_pos++;
+               }
+               yaffs_search_advance(sc);
+       }
+
+out:
+       yaffs_search_end(sc);
+       yaffs_dev_to_lc(dev)->readdir_process = NULL;
+       yaffs_gross_unlock(dev);
+
+       return ret_val;
+}
+
+static const struct file_operations yaffs_dir_operations = {
+       .read = generic_read_dir,
+       .readdir = yaffs_readdir,
+       .fsync = yaffs_sync_object,
+       .llseek = generic_file_llseek,
+};
+
+
+
+static int yaffs_file_flush(struct file *file, fl_owner_t id)
+{
+       struct yaffs_obj *obj = yaffs_dentry_to_obj(file->f_dentry);
+
+       struct yaffs_dev *dev = obj->my_dev;
+
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_file_flush object %d (%s)",
+               obj->obj_id, obj->dirty ? "dirty" : "clean");
+
+       yaffs_gross_lock(dev);
+
+       yaffs_flush_file(obj, 1, 0);
+
+       yaffs_gross_unlock(dev);
+
+       return 0;
+}
+
+static const struct file_operations yaffs_file_operations = {
+       .read = do_sync_read,
+       .write = do_sync_write,
+       .aio_read = generic_file_aio_read,
+       .aio_write = generic_file_aio_write,
+       .mmap = generic_file_mmap,
+       .flush = yaffs_file_flush,
+       .fsync = yaffs_sync_object,
+       .splice_read = generic_file_splice_read,
+       .splice_write = generic_file_splice_write,
+       .llseek = generic_file_llseek,
+};
+
+
+/* ExportFS support */
+static struct inode *yaffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
+                                         uint32_t generation)
+{
+       return yaffs_iget(sb, ino);
+}
+
+static struct dentry *yaffs2_fh_to_dentry(struct super_block *sb,
+                                         struct fid *fid, int fh_len,
+                                         int fh_type)
+{
+       return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
+                                   yaffs2_nfs_get_inode);
+}
+
+static struct dentry *yaffs2_fh_to_parent(struct super_block *sb,
+                                         struct fid *fid, int fh_len,
+                                         int fh_type)
+{
+       return generic_fh_to_parent(sb, fid, fh_len, fh_type,
+                                   yaffs2_nfs_get_inode);
+}
+
+struct dentry *yaffs2_get_parent(struct dentry *dentry)
+{
+
+       struct super_block *sb = dentry->d_inode->i_sb;
+       struct dentry *parent = ERR_PTR(-ENOENT);
+       struct inode *inode;
+       unsigned long parent_ino;
+       struct yaffs_obj *d_obj;
+       struct yaffs_obj *parent_obj;
+
+       d_obj = yaffs_inode_to_obj(dentry->d_inode);
+
+       if (d_obj) {
+               parent_obj = d_obj->parent;
+               if (parent_obj) {
+                       parent_ino = yaffs_get_obj_inode(parent_obj);
+                       inode = yaffs_iget(sb, parent_ino);
+
+                       if (IS_ERR(inode)) {
+                               parent = ERR_CAST(inode);
+                       } else {
+                               parent = d_obtain_alias(inode);
+                               if (!IS_ERR(parent)) {
+                                       parent = ERR_PTR(-ENOMEM);
+                                       iput(inode);
+                               }
+                       }
+               }
+       }
+
+       return parent;
+}
+
+/* Just declare a zero structure as a NULL value implies
+ * using the default functions of exportfs.
+ */
+
+static struct export_operations yaffs_export_ops = {
+       .fh_to_dentry = yaffs2_fh_to_dentry,
+       .fh_to_parent = yaffs2_fh_to_parent,
+       .get_parent = yaffs2_get_parent,
+};
+
+
+/*-----------------------------------------------------------------*/
+
+static int yaffs_readlink(struct dentry *dentry, char __user * buffer,
+                         int buflen)
+{
+       unsigned char *alias;
+       int ret;
+
+       struct yaffs_dev *dev = yaffs_dentry_to_obj(dentry)->my_dev;
+
+       yaffs_gross_lock(dev);
+
+       alias = yaffs_get_symlink_alias(yaffs_dentry_to_obj(dentry));
+
+       yaffs_gross_unlock(dev);
+
+       if (!alias)
+               return -ENOMEM;
+
+       ret = vfs_readlink(dentry, buffer, buflen, alias);
+       kfree(alias);
+       return ret;
+}
+
+static void *yaffs_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+       unsigned char *alias;
+       void *ret;
+       struct yaffs_dev *dev = yaffs_dentry_to_obj(dentry)->my_dev;
+
+       yaffs_gross_lock(dev);
+
+       alias = yaffs_get_symlink_alias(yaffs_dentry_to_obj(dentry));
+       yaffs_gross_unlock(dev);
+
+       if (!alias) {
+               ret = ERR_PTR(-ENOMEM);
+               goto out;
+       }
+
+       nd_set_link(nd, alias);
+       ret = (void *)alias;
+out:
+       return ret;
+}
+
+void yaffs_put_link(struct dentry *dentry, struct nameidata *nd, void *alias)
+{
+       kfree(alias);
+}
+
+
+static void yaffs_unstitch_obj(struct inode *inode, struct yaffs_obj *obj)
+{
+       /* Clear the association between the inode and
+        * the struct yaffs_obj.
+        */
+       obj->my_inode = NULL;
+       yaffs_inode_to_obj_lv(inode) = NULL;
+
+       /* If the object freeing was deferred, then the real
+        * free happens now.
+        * This should fix the inode inconsistency problem.
+        */
+       yaffs_handle_defered_free(obj);
+}
+
+/* yaffs_evict_inode combines into one operation what was previously done in
+ * yaffs_clear_inode() and yaffs_delete_inode()
+ *
+ */
+static void yaffs_evict_inode(struct inode *inode)
+{
+       struct yaffs_obj *obj;
+       struct yaffs_dev *dev;
+       int deleteme = 0;
+
+       obj = yaffs_inode_to_obj(inode);
+
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_evict_inode: ino %d, count %d %s",
+               (int)inode->i_ino,
+               atomic_read(&inode->i_count),
+               obj ? "object exists" : "null object");
+
+       if (!inode->i_nlink && !is_bad_inode(inode))
+               deleteme = 1;
+       truncate_inode_pages(&inode->i_data, 0);
+       end_writeback(inode);
+
+       if (deleteme && obj) {
+               dev = obj->my_dev;
+               yaffs_gross_lock(dev);
+               yaffs_del_obj(obj);
+               yaffs_gross_unlock(dev);
+       }
+       if (obj) {
+               dev = obj->my_dev;
+               yaffs_gross_lock(dev);
+               yaffs_unstitch_obj(inode, obj);
+               yaffs_gross_unlock(dev);
+       }
+
+}
+
+static void yaffs_touch_super(struct yaffs_dev *dev)
+{
+       struct super_block *sb = yaffs_dev_to_lc(dev)->super;
+
+       yaffs_trace(YAFFS_TRACE_OS, "yaffs_touch_super() sb = %p", sb);
+       if (sb)
+               sb->s_dirt = 1;
+}
+
+static int yaffs_readpage_nolock(struct file *f, struct page *pg)
+{
+       /* Lifted from jffs2 */
+
+       struct yaffs_obj *obj;
+       unsigned char *pg_buf;
+       int ret;
+
+       struct yaffs_dev *dev;
+
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_readpage_nolock at %08x, size %08x",
+               (unsigned)(pg->index << PAGE_CACHE_SHIFT),
+               (unsigned)PAGE_CACHE_SIZE);
+
+       obj = yaffs_dentry_to_obj(f->f_dentry);
+
+       dev = obj->my_dev;
+
+       BUG_ON(!PageLocked(pg));
+
+       pg_buf = kmap(pg);
+       /* FIXME: Can kmap fail? */
+
+       yaffs_gross_lock(dev);
+
+       ret = yaffs_file_rd(obj, pg_buf,
+                           pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE);
+
+       yaffs_gross_unlock(dev);
+
+       if (ret >= 0)
+               ret = 0;
+
+       if (ret) {
+               ClearPageUptodate(pg);
+               SetPageError(pg);
+       } else {
+               SetPageUptodate(pg);
+               ClearPageError(pg);
+       }
+
+       flush_dcache_page(pg);
+       kunmap(pg);
+
+       yaffs_trace(YAFFS_TRACE_OS, "yaffs_readpage_nolock done");
+       return ret;
+}
+
+static int yaffs_readpage_unlock(struct file *f, struct page *pg)
+{
+       int ret = yaffs_readpage_nolock(f, pg);
+       UnlockPage(pg);
+       return ret;
+}
+
+static int yaffs_readpage(struct file *f, struct page *pg)
+{
+       int ret;
+
+       yaffs_trace(YAFFS_TRACE_OS, "yaffs_readpage");
+       ret = yaffs_readpage_unlock(f, pg);
+       yaffs_trace(YAFFS_TRACE_OS, "yaffs_readpage done");
+       return ret;
+}
+
+/* writepage inspired by/stolen from smbfs */
+
+static int yaffs_writepage(struct page *page, struct writeback_control *wbc)
+{
+       struct yaffs_dev *dev;
+       struct address_space *mapping = page->mapping;
+       struct inode *inode;
+       unsigned long end_index;
+       char *buffer;
+       struct yaffs_obj *obj;
+       int n_written = 0;
+       unsigned n_bytes;
+       loff_t i_size;
+
+       if (!mapping)
+               BUG();
+       inode = mapping->host;
+       if (!inode)
+               BUG();
+       i_size = i_size_read(inode);
+
+       end_index = i_size >> PAGE_CACHE_SHIFT;
+
+       if (page->index < end_index)
+               n_bytes = PAGE_CACHE_SIZE;
+       else {
+               n_bytes = i_size & (PAGE_CACHE_SIZE - 1);
+
+               if (page->index > end_index || !n_bytes) {
+                       yaffs_trace(YAFFS_TRACE_OS,
+                               "yaffs_writepage at %08x, inode size = %08x!!!",
+                               (unsigned)(page->index << PAGE_CACHE_SHIFT),
+                               (unsigned)inode->i_size);
+                       yaffs_trace(YAFFS_TRACE_OS,
+                         "                -> don't care!!");
+
+                       zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+                       set_page_writeback(page);
+                       unlock_page(page);
+                       end_page_writeback(page);
+                       return 0;
+               }
+       }
+
+       if (n_bytes != PAGE_CACHE_SIZE)
+               zero_user_segment(page, n_bytes, PAGE_CACHE_SIZE);
+
+       get_page(page);
+
+       buffer = kmap(page);
+
+       obj = yaffs_inode_to_obj(inode);
+       dev = obj->my_dev;
+       yaffs_gross_lock(dev);
+
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_writepage at %08x, size %08x",
+               (unsigned)(page->index << PAGE_CACHE_SHIFT), n_bytes);
+       yaffs_trace(YAFFS_TRACE_OS,
+               "writepag0: obj = %05x, ino = %05x",
+               (int)obj->variant.file_variant.file_size, (int)inode->i_size);
+
+       n_written = yaffs_wr_file(obj, buffer,
+                                 page->index << PAGE_CACHE_SHIFT, n_bytes, 0);
+
+       yaffs_touch_super(dev);
+
+       yaffs_trace(YAFFS_TRACE_OS,
+               "writepag1: obj = %05x, ino = %05x",
+               (int)obj->variant.file_variant.file_size, (int)inode->i_size);
+
+       yaffs_gross_unlock(dev);
+
+       kunmap(page);
+       set_page_writeback(page);
+       unlock_page(page);
+       end_page_writeback(page);
+       put_page(page);
+
+       return (n_written == n_bytes) ? 0 : -ENOSPC;
+}
+
+/* Space holding and freeing is done to ensure we have space available for 
+ * write_begin/end.
+ * For now we just assume few parallel writes and check against a small
+ * number.
+ * Todo: need to do this with a counter to handle parallel reads better.
+ */
+
+static ssize_t yaffs_hold_space(struct file *f)
+{
+       struct yaffs_obj *obj;
+       struct yaffs_dev *dev;
+
+       int n_free_chunks;
+
+       obj = yaffs_dentry_to_obj(f->f_dentry);
+
+       dev = obj->my_dev;
+
+       yaffs_gross_lock(dev);
+
+       n_free_chunks = yaffs_get_n_free_chunks(dev);
+
+       yaffs_gross_unlock(dev);
+
+       return (n_free_chunks > 20) ? 1 : 0;
+}
+
+static void yaffs_release_space(struct file *f)
+{
+       struct yaffs_obj *obj;
+       struct yaffs_dev *dev;
+
+       obj = yaffs_dentry_to_obj(f->f_dentry);
+
+       dev = obj->my_dev;
+
+       yaffs_gross_lock(dev);
+
+       yaffs_gross_unlock(dev);
+}
+
+static int yaffs_write_begin(struct file *filp, struct address_space *mapping,
+                            loff_t pos, unsigned len, unsigned flags,
+                            struct page **pagep, void **fsdata)
+{
+       struct page *pg = NULL;
+       pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+
+       int ret = 0;
+       int space_held = 0;
+
+       /* Get a page */
+       pg = grab_cache_page_write_begin(mapping, index, flags);
+
+       *pagep = pg;
+       if (!pg) {
+               ret = -ENOMEM;
+               goto out;
+       }
+       yaffs_trace(YAFFS_TRACE_OS,
+               "start yaffs_write_begin index %d(%x) uptodate %d",
+               (int)index, (int)index, Page_Uptodate(pg) ? 1 : 0);
+
+       /* Get fs space */
+       space_held = yaffs_hold_space(filp);
+
+       if (!space_held) {
+               ret = -ENOSPC;
+               goto out;
+       }
+
+       /* Update page if required */
+
+       if (!Page_Uptodate(pg))
+               ret = yaffs_readpage_nolock(filp, pg);
+
+       if (ret)
+               goto out;
+
+       /* Happy path return */
+       yaffs_trace(YAFFS_TRACE_OS, "end yaffs_write_begin - ok");
+
+       return 0;
+
+out:
+       yaffs_trace(YAFFS_TRACE_OS,
+               "end yaffs_write_begin fail returning %d", ret);
+       if (space_held)
+               yaffs_release_space(filp);
+       if (pg) {
+               unlock_page(pg);
+               page_cache_release(pg);
+       }
+       return ret;
+}
+
+static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n,
+                               loff_t * pos)
+{
+       struct yaffs_obj *obj;
+       int n_written, ipos;
+       struct inode *inode;
+       struct yaffs_dev *dev;
+
+       obj = yaffs_dentry_to_obj(f->f_dentry);
+
+       dev = obj->my_dev;
+
+       yaffs_gross_lock(dev);
+
+       inode = f->f_dentry->d_inode;
+
+       if (!S_ISBLK(inode->i_mode) && f->f_flags & O_APPEND)
+               ipos = inode->i_size;
+       else
+               ipos = *pos;
+
+       if (!obj)
+               yaffs_trace(YAFFS_TRACE_OS,
+                       "yaffs_file_write: hey obj is null!");
+       else
+               yaffs_trace(YAFFS_TRACE_OS,
+                       "yaffs_file_write about to write writing %u(%x) bytes to object %d at %d(%x)",
+                       (unsigned)n, (unsigned)n, obj->obj_id, ipos, ipos);
+
+       n_written = yaffs_wr_file(obj, buf, ipos, n, 0);
+
+       yaffs_touch_super(dev);
+
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_file_write: %d(%x) bytes written",
+               (unsigned)n, (unsigned)n);
+
+       if (n_written > 0) {
+               ipos += n_written;
+               *pos = ipos;
+               if (ipos > inode->i_size) {
+                       inode->i_size = ipos;
+                       inode->i_blocks = (ipos + 511) >> 9;
+
+                       yaffs_trace(YAFFS_TRACE_OS,
+                               "yaffs_file_write size updated to %d bytes, %d blocks",
+                               ipos, (int)(inode->i_blocks));
+               }
+
+       }
+       yaffs_gross_unlock(dev);
+       return (n_written == 0) && (n > 0) ? -ENOSPC : n_written;
+}
+
+static int yaffs_write_end(struct file *filp, struct address_space *mapping,
+                          loff_t pos, unsigned len, unsigned copied,
+                          struct page *pg, void *fsdadata)
+{
+       int ret = 0;
+       void *addr, *kva;
+       uint32_t offset_into_page = pos & (PAGE_CACHE_SIZE - 1);
+
+       kva = kmap(pg);
+       addr = kva + offset_into_page;
+
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_write_end addr %p pos %x n_bytes %d",
+               addr, (unsigned)pos, copied);
+
+       ret = yaffs_file_write(filp, addr, copied, &pos);
+
+       if (ret != copied) {
+               yaffs_trace(YAFFS_TRACE_OS,
+                       "yaffs_write_end not same size ret %d  copied %d",
+                       ret, copied);
+               SetPageError(pg);
+       }
+
+       kunmap(pg);
+
+       yaffs_release_space(filp);
+       unlock_page(pg);
+       page_cache_release(pg);
+       return ret;
+}
+
+static int yaffs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+       struct yaffs_dev *dev = yaffs_dentry_to_obj(dentry)->my_dev;
+       struct super_block *sb = dentry->d_sb;
+
+       yaffs_trace(YAFFS_TRACE_OS, "yaffs_statfs");
+
+       yaffs_gross_lock(dev);
+
+       buf->f_type = YAFFS_MAGIC;
+       buf->f_bsize = sb->s_blocksize;
+       buf->f_namelen = 255;
+
+       if (dev->data_bytes_per_chunk & (dev->data_bytes_per_chunk - 1)) {
+               /* Do this if chunk size is not a power of 2 */
+
+               uint64_t bytes_in_dev;
+               uint64_t bytes_free;
+
+               bytes_in_dev =
+                   ((uint64_t)
+                    ((dev->param.end_block - dev->param.start_block +
+                      1))) * ((uint64_t) (dev->param.chunks_per_block *
+                                          dev->data_bytes_per_chunk));
+
+               do_div(bytes_in_dev, sb->s_blocksize);  /* bytes_in_dev becomes the number of blocks */
+               buf->f_blocks = bytes_in_dev;
+
+               bytes_free = ((uint64_t) (yaffs_get_n_free_chunks(dev))) *
+                   ((uint64_t) (dev->data_bytes_per_chunk));
+
+               do_div(bytes_free, sb->s_blocksize);
+
+               buf->f_bfree = bytes_free;
+
+       } else if (sb->s_blocksize > dev->data_bytes_per_chunk) {
+
+               buf->f_blocks =
+                   (dev->param.end_block - dev->param.start_block + 1) *
+                   dev->param.chunks_per_block /
+                   (sb->s_blocksize / dev->data_bytes_per_chunk);
+               buf->f_bfree =
+                   yaffs_get_n_free_chunks(dev) /
+                   (sb->s_blocksize / dev->data_bytes_per_chunk);
+       } else {
+               buf->f_blocks =
+                   (dev->param.end_block - dev->param.start_block + 1) *
+                   dev->param.chunks_per_block *
+                   (dev->data_bytes_per_chunk / sb->s_blocksize);
+
+               buf->f_bfree =
+                   yaffs_get_n_free_chunks(dev) *
+                   (dev->data_bytes_per_chunk / sb->s_blocksize);
+       }
+
+       buf->f_files = 0;
+       buf->f_ffree = 0;
+       buf->f_bavail = buf->f_bfree;
+
+       yaffs_gross_unlock(dev);
+       return 0;
+}
+
+static void yaffs_flush_inodes(struct super_block *sb)
+{
+       struct inode *iptr;
+       struct yaffs_obj *obj;
+
+       list_for_each_entry(iptr, &sb->s_inodes, i_sb_list) {
+               obj = yaffs_inode_to_obj(iptr);
+               if (obj) {
+                       yaffs_trace(YAFFS_TRACE_OS,
+                               "flushing obj %d", obj->obj_id);
+                       yaffs_flush_file(obj, 1, 0);
+               }
+       }
+}
+
+static void yaffs_flush_super(struct super_block *sb, int do_checkpoint)
+{
+       struct yaffs_dev *dev = yaffs_super_to_dev(sb);
+       if (!dev)
+               return;
+
+       yaffs_flush_inodes(sb);
+       yaffs_update_dirty_dirs(dev);
+       yaffs_flush_whole_cache(dev);
+       if (do_checkpoint)
+               yaffs_checkpoint_save(dev);
+}
+
+static unsigned yaffs_bg_gc_urgency(struct yaffs_dev *dev)
+{
+       unsigned erased_chunks =
+           dev->n_erased_blocks * dev->param.chunks_per_block;
+       struct yaffs_linux_context *context = yaffs_dev_to_lc(dev);
+       unsigned scattered = 0; /* Free chunks not in an erased block */
+
+       if (erased_chunks < dev->n_free_chunks)
+               scattered = (dev->n_free_chunks - erased_chunks);
+
+       if (!context->bg_running)
+               return 0;
+       else if (scattered < (dev->param.chunks_per_block * 2))
+               return 0;
+       else if (erased_chunks > dev->n_free_chunks / 2)
+               return 0;
+       else if (erased_chunks > dev->n_free_chunks / 4)
+               return 1;
+       else
+               return 2;
+}
+
+static int yaffs_do_sync_fs(struct super_block *sb, int request_checkpoint)
+{
+
+       struct yaffs_dev *dev = yaffs_super_to_dev(sb);
+       unsigned int oneshot_checkpoint = (yaffs_auto_checkpoint & 4);
+       unsigned gc_urgent = yaffs_bg_gc_urgency(dev);
+       int do_checkpoint;
+
+       yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC | YAFFS_TRACE_BACKGROUND,
+               "yaffs_do_sync_fs: gc-urgency %d %s %s%s",
+               gc_urgent,
+               sb->s_dirt ? "dirty" : "clean",
+               request_checkpoint ? "checkpoint requested" : "no checkpoint",
+               oneshot_checkpoint ? " one-shot" : "");
+
+       yaffs_gross_lock(dev);
+       do_checkpoint = ((request_checkpoint && !gc_urgent) ||
+                        oneshot_checkpoint) && !dev->is_checkpointed;
+
+       if (sb->s_dirt || do_checkpoint) {
+               yaffs_flush_super(sb, !dev->is_checkpointed && do_checkpoint);
+               sb->s_dirt = 0;
+               if (oneshot_checkpoint)
+                       yaffs_auto_checkpoint &= ~4;
+       }
+       yaffs_gross_unlock(dev);
+
+       return 0;
+}
+
+/*
+ * yaffs background thread functions .
+ * yaffs_bg_thread_fn() the thread function
+ * yaffs_bg_start() launches the background thread.
+ * yaffs_bg_stop() cleans up the background thread.
+ *
+ * NB: 
+ * The thread should only run after the yaffs is initialised
+ * The thread should be stopped before yaffs is unmounted.
+ * The thread should not do any writing while the fs is in read only.
+ */
+
+void yaffs_background_waker(unsigned long data)
+{
+       wake_up_process((struct task_struct *)data);
+}
+
+static int yaffs_bg_thread_fn(void *data)
+{
+       struct yaffs_dev *dev = (struct yaffs_dev *)data;
+       struct yaffs_linux_context *context = yaffs_dev_to_lc(dev);
+       unsigned long now = jiffies;
+       unsigned long next_dir_update = now;
+       unsigned long next_gc = now;
+       unsigned long expires;
+       unsigned int urgency;
+
+       int gc_result;
+       struct timer_list timer;
+
+       yaffs_trace(YAFFS_TRACE_BACKGROUND,
+               "yaffs_background starting for dev %p", (void *)dev);
+
+       set_freezable();
+       while (context->bg_running) {
+               yaffs_trace(YAFFS_TRACE_BACKGROUND, "yaffs_background");
+
+               if (kthread_should_stop())
+                       break;
+
+               if (try_to_freeze())
+                       continue;
+
+               yaffs_gross_lock(dev);
+
+               now = jiffies;
+
+               if (time_after(now, next_dir_update) && yaffs_bg_enable) {
+                       yaffs_update_dirty_dirs(dev);
+                       next_dir_update = now + HZ;
+               }
+
+               if (time_after(now, next_gc) && yaffs_bg_enable) {
+                       if (!dev->is_checkpointed) {
+                               urgency = yaffs_bg_gc_urgency(dev);
+                               gc_result = yaffs_bg_gc(dev, urgency);
+                               if (urgency > 1)
+                                       next_gc = now + HZ / 20 + 1;
+                               else if (urgency > 0)
+                                       next_gc = now + HZ / 10 + 1;
+                               else
+                                       next_gc = now + HZ * 2;
+                       } else  {
+                               /*
+                                * gc not running so set to next_dir_update
+                                * to cut down on wake ups
+                                */
+                               next_gc = next_dir_update;
+                        }
+               }
+               yaffs_gross_unlock(dev);
+               expires = next_dir_update;
+               if (time_before(next_gc, expires))
+                       expires = next_gc;
+               if (time_before(expires, now))
+                       expires = now + HZ;
+
+               Y_INIT_TIMER(&timer);
+               timer.expires = expires + 1;
+               timer.data = (unsigned long)current;
+               timer.function = yaffs_background_waker;
+
+               set_current_state(TASK_INTERRUPTIBLE);
+               add_timer(&timer);
+               schedule();
+               del_timer_sync(&timer);
+       }
+
+       return 0;
+}
+
+static int yaffs_bg_start(struct yaffs_dev *dev)
+{
+       int retval = 0;
+       struct yaffs_linux_context *context = yaffs_dev_to_lc(dev);
+
+       if (dev->read_only)
+               return -1;
+
+       context->bg_running = 1;
+
+       context->bg_thread = kthread_run(yaffs_bg_thread_fn,
+                                        (void *)dev, "yaffs-bg-%d",
+                                        context->mount_id);
+
+       if (IS_ERR(context->bg_thread)) {
+               retval = PTR_ERR(context->bg_thread);
+               context->bg_thread = NULL;
+               context->bg_running = 0;
+       }
+       return retval;
+}
+
+static void yaffs_bg_stop(struct yaffs_dev *dev)
+{
+       struct yaffs_linux_context *ctxt = yaffs_dev_to_lc(dev);
+
+       ctxt->bg_running = 0;
+
+       if (ctxt->bg_thread) {
+               kthread_stop(ctxt->bg_thread);
+               ctxt->bg_thread = NULL;
+       }
+}
+
+static void yaffs_write_super(struct super_block *sb)
+{
+       unsigned request_checkpoint = (yaffs_auto_checkpoint >= 2);
+
+       yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC | YAFFS_TRACE_BACKGROUND,
+               "yaffs_write_super%s",
+               request_checkpoint ? " checkpt" : "");
+
+       yaffs_do_sync_fs(sb, request_checkpoint);
+
+}
+
+static int yaffs_sync_fs(struct super_block *sb, int wait)
+{
+       unsigned request_checkpoint = (yaffs_auto_checkpoint >= 1);
+
+       yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC,
+               "yaffs_sync_fs%s", request_checkpoint ? " checkpt" : "");
+
+       yaffs_do_sync_fs(sb, request_checkpoint);
+
+       return 0;
+}
+
+
+static LIST_HEAD(yaffs_context_list);
+struct mutex yaffs_context_lock;
+
+
+
+struct yaffs_options {
+       int inband_tags;
+       int skip_checkpoint_read;
+       int skip_checkpoint_write;
+       int no_cache;
+       int tags_ecc_on;
+       int tags_ecc_overridden;
+       int lazy_loading_enabled;
+       int lazy_loading_overridden;
+       int empty_lost_and_found;
+       int empty_lost_and_found_overridden;
+};
+
+#define MAX_OPT_LEN 30
+static int yaffs_parse_options(struct yaffs_options *options,
+                              const char *options_str)
+{
+       char cur_opt[MAX_OPT_LEN + 1];
+       int p;
+       int error = 0;
+
+       /* Parse through the options which is a comma seperated list */
+
+       while (options_str && *options_str && !error) {
+               memset(cur_opt, 0, MAX_OPT_LEN + 1);
+               p = 0;
+
+               while (*options_str == ',')
+                       options_str++;
+
+               while (*options_str && *options_str != ',') {
+                       if (p < MAX_OPT_LEN) {
+                               cur_opt[p] = *options_str;
+                               p++;
+                       }
+                       options_str++;
+               }
+
+               if (!strcmp(cur_opt, "inband-tags")) {
+                       options->inband_tags = 1;
+               } else if (!strcmp(cur_opt, "tags-ecc-off")) {
+                       options->tags_ecc_on = 0;
+                       options->tags_ecc_overridden = 1;
+               } else if (!strcmp(cur_opt, "tags-ecc-on")) {
+                       options->tags_ecc_on = 1;
+                       options->tags_ecc_overridden = 1;
+               } else if (!strcmp(cur_opt, "lazy-loading-off")) {
+                       options->lazy_loading_enabled = 0;
+                       options->lazy_loading_overridden = 1;
+               } else if (!strcmp(cur_opt, "lazy-loading-on")) {
+                       options->lazy_loading_enabled = 1;
+                       options->lazy_loading_overridden = 1;
+               } else if (!strcmp(cur_opt, "empty-lost-and-found-off")) {
+                       options->empty_lost_and_found = 0;
+                       options->empty_lost_and_found_overridden = 1;
+               } else if (!strcmp(cur_opt, "empty-lost-and-found-on")) {
+                       options->empty_lost_and_found = 1;
+                       options->empty_lost_and_found_overridden = 1;
+               } else if (!strcmp(cur_opt, "no-cache")) {
+                       options->no_cache = 1;
+               } else if (!strcmp(cur_opt, "no-checkpoint-read")) {
+                       options->skip_checkpoint_read = 1;
+               } else if (!strcmp(cur_opt, "no-checkpoint-write")) {
+                       options->skip_checkpoint_write = 1;
+               } else if (!strcmp(cur_opt, "no-checkpoint")) {
+                       options->skip_checkpoint_read = 1;
+                       options->skip_checkpoint_write = 1;
+               } else {
+                       printk(KERN_INFO "yaffs: Bad mount option \"%s\"\n",
+                              cur_opt);
+                       error = 1;
+               }
+       }
+
+       return error;
+}
+
+static struct address_space_operations yaffs_file_address_operations = {
+       .readpage = yaffs_readpage,
+       .writepage = yaffs_writepage,
+       .write_begin = yaffs_write_begin,
+       .write_end = yaffs_write_end,
+};
+
+
+
+static const struct inode_operations yaffs_file_inode_operations = {
+       .setattr = yaffs_setattr,
+#ifdef CONFIG_YAFFS_XATTR
+       .setxattr = yaffs_setxattr,
+       .getxattr = yaffs_getxattr,
+       .listxattr = yaffs_listxattr,
+       .removexattr = yaffs_removexattr,
+#endif
+};
+
+static const struct inode_operations yaffs_symlink_inode_operations = {
+       .readlink = yaffs_readlink,
+       .follow_link = yaffs_follow_link,
+       .put_link = yaffs_put_link,
+       .setattr = yaffs_setattr,
+#ifdef CONFIG_YAFFS_XATTR
+       .setxattr = yaffs_setxattr,
+       .getxattr = yaffs_getxattr,
+       .listxattr = yaffs_listxattr,
+       .removexattr = yaffs_removexattr,
+#endif
+};
+
+static void yaffs_fill_inode_from_obj(struct inode *inode,
+                                     struct yaffs_obj *obj)
+{
+       if (inode && obj) {
+
+               /* Check mode against the variant type and attempt to repair if broken. */
+               u32 mode = obj->yst_mode;
+               switch (obj->variant_type) {
+               case YAFFS_OBJECT_TYPE_FILE:
+                       if (!S_ISREG(mode)) {
+                               obj->yst_mode &= ~S_IFMT;
+                               obj->yst_mode |= S_IFREG;
+                       }
+
+                       break;
+               case YAFFS_OBJECT_TYPE_SYMLINK:
+                       if (!S_ISLNK(mode)) {
+                               obj->yst_mode &= ~S_IFMT;
+                               obj->yst_mode |= S_IFLNK;
+                       }
+
+                       break;
+               case YAFFS_OBJECT_TYPE_DIRECTORY:
+                       if (!S_ISDIR(mode)) {
+                               obj->yst_mode &= ~S_IFMT;
+                               obj->yst_mode |= S_IFDIR;
+                       }
+
+                       break;
+               case YAFFS_OBJECT_TYPE_UNKNOWN:
+               case YAFFS_OBJECT_TYPE_HARDLINK:
+               case YAFFS_OBJECT_TYPE_SPECIAL:
+               default:
+                       /* TODO? */
+                       break;
+               }
+
+               inode->i_flags |= S_NOATIME;
+
+               inode->i_ino = obj->obj_id;
+               inode->i_mode = obj->yst_mode;
+               inode->i_uid = obj->yst_uid;
+               inode->i_gid = obj->yst_gid;
+
+               inode->i_rdev = old_decode_dev(obj->yst_rdev);
+
+               inode->i_atime.tv_sec = (time_t) (obj->yst_atime);
+               inode->i_atime.tv_nsec = 0;
+               inode->i_mtime.tv_sec = (time_t) obj->yst_mtime;
+               inode->i_mtime.tv_nsec = 0;
+               inode->i_ctime.tv_sec = (time_t) obj->yst_ctime;
+               inode->i_ctime.tv_nsec = 0;
+               inode->i_size = yaffs_get_obj_length(obj);
+               inode->i_blocks = (inode->i_size + 511) >> 9;
+
+               inode->i_nlink = yaffs_get_obj_link_count(obj);
+
+               yaffs_trace(YAFFS_TRACE_OS,
+                       "yaffs_fill_inode mode %x uid %d gid %d size %d count %d",
+                       inode->i_mode, inode->i_uid, inode->i_gid,
+                       (int)inode->i_size, atomic_read(&inode->i_count));
+
+               switch (obj->yst_mode & S_IFMT) {
+               default:        /* fifo, device or socket */
+                       init_special_inode(inode, obj->yst_mode,
+                                          old_decode_dev(obj->yst_rdev));
+                       break;
+               case S_IFREG:   /* file */
+                       inode->i_op = &yaffs_file_inode_operations;
+                       inode->i_fop = &yaffs_file_operations;
+                       inode->i_mapping->a_ops =
+                           &yaffs_file_address_operations;
+                       break;
+               case S_IFDIR:   /* directory */
+                       inode->i_op = &yaffs_dir_inode_operations;
+                       inode->i_fop = &yaffs_dir_operations;
+                       break;
+               case S_IFLNK:   /* symlink */
+                       inode->i_op = &yaffs_symlink_inode_operations;
+                       break;
+               }
+
+               yaffs_inode_to_obj_lv(inode) = obj;
+
+               obj->my_inode = inode;
+
+       } else {
+               yaffs_trace(YAFFS_TRACE_OS,
+                       "yaffs_fill_inode invalid parameters");
+       }
+}
+
+static void yaffs_put_super(struct super_block *sb)
+{
+       struct yaffs_dev *dev = yaffs_super_to_dev(sb);
+
+       yaffs_trace(YAFFS_TRACE_OS, "yaffs_put_super");
+
+       yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_BACKGROUND,
+               "Shutting down yaffs background thread");
+       yaffs_bg_stop(dev);
+       yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_BACKGROUND,
+               "yaffs background thread shut down");
+
+       yaffs_gross_lock(dev);
+
+       yaffs_flush_super(sb, 1);
+
+       if (yaffs_dev_to_lc(dev)->put_super_fn)
+               yaffs_dev_to_lc(dev)->put_super_fn(sb);
+
+       yaffs_deinitialise(dev);
+
+       yaffs_gross_unlock(dev);
+       mutex_lock(&yaffs_context_lock);
+       list_del_init(&(yaffs_dev_to_lc(dev)->context_list));
+       mutex_unlock(&yaffs_context_lock);
+
+       if (yaffs_dev_to_lc(dev)->spare_buffer) {
+               kfree(yaffs_dev_to_lc(dev)->spare_buffer);
+               yaffs_dev_to_lc(dev)->spare_buffer = NULL;
+       }
+
+       kfree(dev);
+}
+
+static void yaffs_mtd_put_super(struct super_block *sb)
+{
+       struct mtd_info *mtd = yaffs_dev_to_mtd(yaffs_super_to_dev(sb));
+
+       if (mtd->sync)
+               mtd->sync(mtd);
+
+       put_mtd_device(mtd);
+}
+
+static const struct super_operations yaffs_super_ops = {
+       .statfs = yaffs_statfs,
+       .put_super = yaffs_put_super,
+       .evict_inode = yaffs_evict_inode,
+       .sync_fs = yaffs_sync_fs,
+       .write_super = yaffs_write_super,
+};
+
+static struct super_block *yaffs_internal_read_super(int yaffs_version,
+                                                    struct super_block *sb,
+                                                    void *data, int silent)
+{
+       int n_blocks;
+       struct inode *inode = NULL;
+       struct dentry *root;
+       struct yaffs_dev *dev = 0;
+       char devname_buf[BDEVNAME_SIZE + 1];
+       struct mtd_info *mtd;
+       int err;
+       char *data_str = (char *)data;
+       struct yaffs_linux_context *context = NULL;
+       struct yaffs_param *param;
+
+       int read_only = 0;
+
+       struct yaffs_options options;
+
+       unsigned mount_id;
+       int found;
+       struct yaffs_linux_context *context_iterator;
+       struct list_head *l;
+
+       sb->s_magic = YAFFS_MAGIC;
+       sb->s_op = &yaffs_super_ops;
+       sb->s_flags |= MS_NOATIME;
+
+       read_only = ((sb->s_flags & MS_RDONLY) != 0);
+
+       sb->s_export_op = &yaffs_export_ops;
+
+       if (!sb)
+               printk(KERN_INFO "yaffs: sb is NULL\n");
+       else if (!sb->s_dev)
+               printk(KERN_INFO "yaffs: sb->s_dev is NULL\n");
+       else if (!yaffs_devname(sb, devname_buf))
+               printk(KERN_INFO "yaffs: devname is NULL\n");
+       else
+               printk(KERN_INFO "yaffs: dev is %d name is \"%s\" %s\n",
+                      sb->s_dev,
+                      yaffs_devname(sb, devname_buf), read_only ? "ro" : "rw");
+
+       if (!data_str)
+               data_str = "";
+
+       printk(KERN_INFO "yaffs: passed flags \"%s\"\n", data_str);
+
+       memset(&options, 0, sizeof(options));
+
+       if (yaffs_parse_options(&options, data_str)) {
+               /* Option parsing failed */
+               return NULL;
+       }
+
+       sb->s_blocksize = PAGE_CACHE_SIZE;
+       sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_read_super: Using yaffs%d", yaffs_version);
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_read_super: block size %d", (int)(sb->s_blocksize));
+
+       yaffs_trace(YAFFS_TRACE_ALWAYS,
+               "Attempting MTD mount of %u.%u,\"%s\"",
+               MAJOR(sb->s_dev), MINOR(sb->s_dev),
+               yaffs_devname(sb, devname_buf));
+
+       /* Check it's an mtd device..... */
+       if (MAJOR(sb->s_dev) != MTD_BLOCK_MAJOR)
+               return NULL;    /* This isn't an mtd device */
+
+       /* Get the device */
+       mtd = get_mtd_device(NULL, MINOR(sb->s_dev));
+       if (!mtd) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "MTD device #%u doesn't appear to exist",
+                       MINOR(sb->s_dev));
+               return NULL;
+       }
+       /* Check it's NAND */
+       if (mtd->type != MTD_NANDFLASH) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "MTD device is not NAND it's type %d",
+                       mtd->type);
+               return NULL;
+       }
+
+       yaffs_trace(YAFFS_TRACE_OS, " erase %p", mtd->erase);
+       yaffs_trace(YAFFS_TRACE_OS, " read %p", mtd->read);
+       yaffs_trace(YAFFS_TRACE_OS, " write %p", mtd->write);
+       yaffs_trace(YAFFS_TRACE_OS, " readoob %p", mtd->read_oob);
+       yaffs_trace(YAFFS_TRACE_OS, " writeoob %p", mtd->write_oob);
+       yaffs_trace(YAFFS_TRACE_OS, " block_isbad %p", mtd->block_isbad);
+       yaffs_trace(YAFFS_TRACE_OS, " block_markbad %p", mtd->block_markbad);
+       yaffs_trace(YAFFS_TRACE_OS, " %s %d", WRITE_SIZE_STR, WRITE_SIZE(mtd));
+       yaffs_trace(YAFFS_TRACE_OS, " oobsize %d", mtd->oobsize);
+       yaffs_trace(YAFFS_TRACE_OS, " erasesize %d", mtd->erasesize);
+       yaffs_trace(YAFFS_TRACE_OS, " size %lld", mtd->size);
+
+#ifdef CONFIG_YAFFS_AUTO_YAFFS2
+
+       if (yaffs_version == 1 && WRITE_SIZE(mtd) >= 2048) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS, "auto selecting yaffs2");
+               yaffs_version = 2;
+       }
+
+       /* Added NCB 26/5/2006 for completeness */
+       if (yaffs_version == 2 && !options.inband_tags
+           && WRITE_SIZE(mtd) == 512) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS, "auto selecting yaffs1");
+               yaffs_version = 1;
+       }
+#endif
+
+       if (yaffs_version == 2) {
+               /* Check for version 2 style functions */
+               if (!mtd->erase ||
+                   !mtd->block_isbad ||
+                   !mtd->block_markbad ||
+                   !mtd->read ||
+                   !mtd->write || !mtd->read_oob || !mtd->write_oob) {
+                       yaffs_trace(YAFFS_TRACE_ALWAYS,
+                               "MTD device does not support required functions");
+                       return NULL;
+               }
+
+               if ((WRITE_SIZE(mtd) < YAFFS_MIN_YAFFS2_CHUNK_SIZE ||
+                    mtd->oobsize < YAFFS_MIN_YAFFS2_SPARE_SIZE) &&
+                   !options.inband_tags) {
+                       yaffs_trace(YAFFS_TRACE_ALWAYS,
+                               "MTD device does not have the right page sizes");
+                       return NULL;
+               }
+       } else {
+               /* Check for V1 style functions */
+               if (!mtd->erase ||
+                   !mtd->read ||
+                   !mtd->write || !mtd->read_oob || !mtd->write_oob) {
+                       yaffs_trace(YAFFS_TRACE_ALWAYS,
+                               "MTD device does not support required functions");
+                       return NULL;
+               }
+
+               if (WRITE_SIZE(mtd) < YAFFS_BYTES_PER_CHUNK ||
+                   mtd->oobsize != YAFFS_BYTES_PER_SPARE) {
+                       yaffs_trace(YAFFS_TRACE_ALWAYS,
+                               "MTD device does not support have the right page sizes");
+                       return NULL;
+               }
+       }
+
+       /* OK, so if we got here, we have an MTD that's NAND and looks
+        * like it has the right capabilities
+        * Set the struct yaffs_dev up for mtd
+        */
+
+       if (!read_only && !(mtd->flags & MTD_WRITEABLE)) {
+               read_only = 1;
+               printk(KERN_INFO
+                      "yaffs: mtd is read only, setting superblock read only");
+               sb->s_flags |= MS_RDONLY;
+       }
+
+       dev = kmalloc(sizeof(struct yaffs_dev), GFP_KERNEL);
+       context = kmalloc(sizeof(struct yaffs_linux_context), GFP_KERNEL);
+
+       if (!dev || !context) {
+               if (dev)
+                       kfree(dev);
+               if (context)
+                       kfree(context);
+               dev = NULL;
+               context = NULL;
+       }
+
+       if (!dev) {
+               /* Deep shit could not allocate device structure */
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "yaffs_read_super failed trying to allocate yaffs_dev");
+               return NULL;
+       }
+       memset(dev, 0, sizeof(struct yaffs_dev));
+       param = &(dev->param);
+
+       memset(context, 0, sizeof(struct yaffs_linux_context));
+       dev->os_context = context;
+       INIT_LIST_HEAD(&(context->context_list));
+       context->dev = dev;
+       context->super = sb;
+
+       dev->read_only = read_only;
+
+       sb->s_fs_info = dev;
+
+       dev->driver_context = mtd;
+       param->name = mtd->name;
+
+       /* Set up the memory size parameters.... */
+
+       n_blocks =
+           YCALCBLOCKS(mtd->size,
+                       (YAFFS_CHUNKS_PER_BLOCK * YAFFS_BYTES_PER_CHUNK));
+
+       param->start_block = 0;
+       param->end_block = n_blocks - 1;
+       param->chunks_per_block = YAFFS_CHUNKS_PER_BLOCK;
+       param->total_bytes_per_chunk = YAFFS_BYTES_PER_CHUNK;
+       param->n_reserved_blocks = 5;
+       param->n_caches = (options.no_cache) ? 0 : 10;
+       param->inband_tags = options.inband_tags;
+
+#ifdef CONFIG_YAFFS_DISABLE_LAZY_LOAD
+       param->disable_lazy_load = 1;
+#endif
+#ifdef CONFIG_YAFFS_XATTR
+       param->enable_xattr = 1;
+#endif
+       if (options.lazy_loading_overridden)
+               param->disable_lazy_load = !options.lazy_loading_enabled;
+
+#ifdef CONFIG_YAFFS_DISABLE_TAGS_ECC
+       param->no_tags_ecc = 1;
+#endif
+
+#ifdef CONFIG_YAFFS_DISABLE_BACKGROUND
+#else
+       param->defered_dir_update = 1;
+#endif
+
+       if (options.tags_ecc_overridden)
+               param->no_tags_ecc = !options.tags_ecc_on;
+
+#ifdef CONFIG_YAFFS_EMPTY_LOST_AND_FOUND
+       param->empty_lost_n_found = 1;
+#endif
+
+#ifdef CONFIG_YAFFS_DISABLE_BLOCK_REFRESHING
+       param->refresh_period = 0;
+#else
+       param->refresh_period = 500;
+#endif
+
+#ifdef CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED
+       param->always_check_erased = 1;
+#endif
+
+       if (options.empty_lost_and_found_overridden)
+               param->empty_lost_n_found = options.empty_lost_and_found;
+
+       /* ... and the functions. */
+       if (yaffs_version == 2) {
+               param->write_chunk_tags_fn = nandmtd2_write_chunk_tags;
+               param->read_chunk_tags_fn = nandmtd2_read_chunk_tags;
+               param->bad_block_fn = nandmtd2_mark_block_bad;
+               param->query_block_fn = nandmtd2_query_block;
+               yaffs_dev_to_lc(dev)->spare_buffer = 
+                               kmalloc(mtd->oobsize, GFP_NOFS);
+               param->is_yaffs2 = 1;
+               param->total_bytes_per_chunk = mtd->writesize;
+               param->chunks_per_block = mtd->erasesize / mtd->writesize;
+               n_blocks = YCALCBLOCKS(mtd->size, mtd->erasesize);
+
+               param->start_block = 0;
+               param->end_block = n_blocks - 1;
+       } else {
+               /* use the MTD interface in yaffs_mtdif1.c */
+               param->write_chunk_tags_fn = nandmtd1_write_chunk_tags;
+               param->read_chunk_tags_fn = nandmtd1_read_chunk_tags;
+               param->bad_block_fn = nandmtd1_mark_block_bad;
+               param->query_block_fn = nandmtd1_query_block;
+               param->is_yaffs2 = 0;
+       }
+       /* ... and common functions */
+       param->erase_fn = nandmtd_erase_block;
+       param->initialise_flash_fn = nandmtd_initialise;
+
+       yaffs_dev_to_lc(dev)->put_super_fn = yaffs_mtd_put_super;
+
+       param->sb_dirty_fn = yaffs_touch_super;
+       param->gc_control = yaffs_gc_control_callback;
+
+       yaffs_dev_to_lc(dev)->super = sb;
+
+#ifndef CONFIG_YAFFS_DOES_ECC
+       param->use_nand_ecc = 1;
+#endif
+
+       param->skip_checkpt_rd = options.skip_checkpoint_read;
+       param->skip_checkpt_wr = options.skip_checkpoint_write;
+
+       mutex_lock(&yaffs_context_lock);
+       /* Get a mount id */
+       found = 0;
+       for (mount_id = 0; !found; mount_id++) {
+               found = 1;
+               list_for_each(l, &yaffs_context_list) {
+                       context_iterator =
+                           list_entry(l, struct yaffs_linux_context,
+                                      context_list);
+                       if (context_iterator->mount_id == mount_id)
+                               found = 0;
+               }
+       }
+       context->mount_id = mount_id;
+
+       list_add_tail(&(yaffs_dev_to_lc(dev)->context_list),
+                     &yaffs_context_list);
+       mutex_unlock(&yaffs_context_lock);
+
+       /* Directory search handling... */
+       INIT_LIST_HEAD(&(yaffs_dev_to_lc(dev)->search_contexts));
+       param->remove_obj_fn = yaffs_remove_obj_callback;
+
+       mutex_init(&(yaffs_dev_to_lc(dev)->gross_lock));
+
+       yaffs_gross_lock(dev);
+
+       err = yaffs_guts_initialise(dev);
+
+       yaffs_trace(YAFFS_TRACE_OS,
+               "yaffs_read_super: guts initialised %s",
+               (err == YAFFS_OK) ? "OK" : "FAILED");
+
+       if (err == YAFFS_OK)
+               yaffs_bg_start(dev);
+
+       if (!context->bg_thread)
+               param->defered_dir_update = 0;
+
+       /* Release lock before yaffs_get_inode() */
+       yaffs_gross_unlock(dev);
+
+       /* Create root inode */
+       if (err == YAFFS_OK)
+               inode = yaffs_get_inode(sb, S_IFDIR | 0755, 0, yaffs_root(dev));
+
+       if (!inode)
+               return NULL;
+
+       inode->i_op = &yaffs_dir_inode_operations;
+       inode->i_fop = &yaffs_dir_operations;
+
+       yaffs_trace(YAFFS_TRACE_OS, "yaffs_read_super: got root inode");
+
+       root = d_alloc_root(inode);
+
+       yaffs_trace(YAFFS_TRACE_OS, "yaffs_read_super: d_alloc_root done");
+
+       if (!root) {
+               iput(inode);
+               return NULL;
+       }
+       sb->s_root = root;
+       sb->s_dirt = !dev->is_checkpointed;
+       yaffs_trace(YAFFS_TRACE_ALWAYS,
+               "yaffs_read_super: is_checkpointed %d",
+               dev->is_checkpointed);
+
+       yaffs_trace(YAFFS_TRACE_OS, "yaffs_read_super: done");
+       return sb;
+}
+
+static int yaffs_internal_read_super_mtd(struct super_block *sb, void *data,
+                                        int silent)
+{
+       return yaffs_internal_read_super(1, sb, data, silent) ? 0 : -EINVAL;
+}
+
+static int yaffs_read_super(struct file_system_type *fs,
+                           int flags, const char *dev_name,
+                           void *data, struct vfsmount *mnt)
+{
+
+       return get_sb_bdev(fs, flags, dev_name, data,
+                          yaffs_internal_read_super_mtd, mnt);
+}
+
+static struct file_system_type yaffs_fs_type = {
+       .owner = THIS_MODULE,
+       .name = "yaffs",
+       .get_sb = yaffs_read_super,
+       .kill_sb = kill_block_super,
+       .fs_flags = FS_REQUIRES_DEV,
+};
+
+#ifdef CONFIG_YAFFS_YAFFS2
+
+static int yaffs2_internal_read_super_mtd(struct super_block *sb, void *data,
+                                         int silent)
+{
+       return yaffs_internal_read_super(2, sb, data, silent) ? 0 : -EINVAL;
+}
+
+static int yaffs2_read_super(struct file_system_type *fs,
+                            int flags, const char *dev_name, void *data,
+                            struct vfsmount *mnt)
+{
+       return get_sb_bdev(fs, flags, dev_name, data,
+                          yaffs2_internal_read_super_mtd, mnt);
+}
+
+static struct file_system_type yaffs2_fs_type = {
+       .owner = THIS_MODULE,
+       .name = "yaffs2",
+       .get_sb = yaffs2_read_super,
+       .kill_sb = kill_block_super,
+       .fs_flags = FS_REQUIRES_DEV,
+};
+#endif /* CONFIG_YAFFS_YAFFS2 */
+
+static struct proc_dir_entry *my_proc_entry;
+
+static char *yaffs_dump_dev_part0(char *buf, struct yaffs_dev *dev)
+{
+       struct yaffs_param *param = &dev->param;
+       buf += sprintf(buf, "start_block........... %d\n", param->start_block);
+       buf += sprintf(buf, "end_block............. %d\n", param->end_block);
+       buf += sprintf(buf, "total_bytes_per_chunk. %d\n",
+                       param->total_bytes_per_chunk);
+       buf += sprintf(buf, "use_nand_ecc.......... %d\n",
+                       param->use_nand_ecc);
+       buf += sprintf(buf, "no_tags_ecc........... %d\n", param->no_tags_ecc);
+       buf += sprintf(buf, "is_yaffs2............. %d\n", param->is_yaffs2);
+       buf += sprintf(buf, "inband_tags........... %d\n", param->inband_tags);
+       buf += sprintf(buf, "empty_lost_n_found.... %d\n",
+                       param->empty_lost_n_found);
+       buf += sprintf(buf, "disable_lazy_load..... %d\n",
+                       param->disable_lazy_load);
+       buf += sprintf(buf, "refresh_period........ %d\n",
+                       param->refresh_period);
+       buf += sprintf(buf, "n_caches.............. %d\n", param->n_caches);
+       buf += sprintf(buf, "n_reserved_blocks..... %d\n",
+                       param->n_reserved_blocks);
+       buf += sprintf(buf, "always_check_erased... %d\n",
+                       param->always_check_erased);
+
+       return buf;
+}
+
+static char *yaffs_dump_dev_part1(char *buf, struct yaffs_dev *dev)
+{
+       buf +=
+           sprintf(buf, "data_bytes_per_chunk.. %d\n",
+                   dev->data_bytes_per_chunk);
+       buf += sprintf(buf, "chunk_grp_bits........ %d\n", dev->chunk_grp_bits);
+       buf += sprintf(buf, "chunk_grp_size........ %d\n", dev->chunk_grp_size);
+       buf +=
+           sprintf(buf, "n_erased_blocks....... %d\n", dev->n_erased_blocks);
+       buf +=
+           sprintf(buf, "blocks_in_checkpt..... %d\n", dev->blocks_in_checkpt);
+       buf += sprintf(buf, "\n");
+       buf += sprintf(buf, "n_tnodes.............. %d\n", dev->n_tnodes);
+       buf += sprintf(buf, "n_obj................. %d\n", dev->n_obj);
+       buf += sprintf(buf, "n_free_chunks......... %d\n", dev->n_free_chunks);
+       buf += sprintf(buf, "\n");
+       buf += sprintf(buf, "n_page_writes......... %u\n", dev->n_page_writes);
+       buf += sprintf(buf, "n_page_reads.......... %u\n", dev->n_page_reads);
+       buf += sprintf(buf, "n_erasures............ %u\n", dev->n_erasures);
+       buf += sprintf(buf, "n_gc_copies........... %u\n", dev->n_gc_copies);
+       buf += sprintf(buf, "all_gcs............... %u\n", dev->all_gcs);
+       buf +=
+           sprintf(buf, "passive_gc_count...... %u\n", dev->passive_gc_count);
+       buf +=
+           sprintf(buf, "oldest_dirty_gc_count. %u\n",
+                   dev->oldest_dirty_gc_count);
+       buf += sprintf(buf, "n_gc_blocks........... %u\n", dev->n_gc_blocks);
+       buf += sprintf(buf, "bg_gcs................ %u\n", dev->bg_gcs);
+       buf +=
+           sprintf(buf, "n_retired_writes...... %u\n", dev->n_retired_writes);
+       buf +=
+           sprintf(buf, "n_retired_blocks...... %u\n", dev->n_retired_blocks);
+       buf += sprintf(buf, "n_ecc_fixed........... %u\n", dev->n_ecc_fixed);
+       buf += sprintf(buf, "n_ecc_unfixed......... %u\n", dev->n_ecc_unfixed);
+       buf +=
+           sprintf(buf, "n_tags_ecc_fixed...... %u\n", dev->n_tags_ecc_fixed);
+       buf +=
+           sprintf(buf, "n_tags_ecc_unfixed.... %u\n",
+                   dev->n_tags_ecc_unfixed);
+       buf += sprintf(buf, "cache_hits............ %u\n", dev->cache_hits);
+       buf +=
+           sprintf(buf, "n_deleted_files....... %u\n", dev->n_deleted_files);
+       buf +=
+           sprintf(buf, "n_unlinked_files...... %u\n", dev->n_unlinked_files);
+       buf += sprintf(buf, "refresh_count......... %u\n", dev->refresh_count);
+       buf += sprintf(buf, "n_bg_deletions........ %u\n", dev->n_bg_deletions);
+
+       return buf;
+}
+
+static int yaffs_proc_read(char *page,
+                          char **start,
+                          off_t offset, int count, int *eof, void *data)
+{
+       struct list_head *item;
+       char *buf = page;
+       int step = offset;
+       int n = 0;
+
+       /* Get proc_file_read() to step 'offset' by one on each sucessive call.
+        * We use 'offset' (*ppos) to indicate where we are in dev_list.
+        * This also assumes the user has posted a read buffer large
+        * enough to hold the complete output; but that's life in /proc.
+        */
+
+       *(int *)start = 1;
+
+       /* Print header first */
+       if (step == 0)
+               buf += sprintf(buf, "YAFFS built:" __DATE__ " " __TIME__ "\n");
+       else if (step == 1)
+               buf += sprintf(buf, "\n");
+       else {
+               step -= 2;
+
+               mutex_lock(&yaffs_context_lock);
+
+               /* Locate and print the Nth entry.  Order N-squared but N is small. */
+               list_for_each(item, &yaffs_context_list) {
+                       struct yaffs_linux_context *dc =
+                           list_entry(item, struct yaffs_linux_context,
+                                      context_list);
+                       struct yaffs_dev *dev = dc->dev;
+
+                       if (n < (step & ~1)) {
+                               n += 2;
+                               continue;
+                       }
+                       if ((step & 1) == 0) {
+                               buf +=
+                                   sprintf(buf, "\nDevice %d \"%s\"\n", n,
+                                           dev->param.name);
+                               buf = yaffs_dump_dev_part0(buf, dev);
+                       } else {
+                               buf = yaffs_dump_dev_part1(buf, dev);
+                        }
+
+                       break;
+               }
+               mutex_unlock(&yaffs_context_lock);
+       }
+
+       return buf - page < count ? buf - page : count;
+}
+
+
+/**
+ * Set the verbosity of the warnings and error messages.
+ *
+ * Note that the names can only be a..z or _ with the current code.
+ */
+
+static struct {
+       char *mask_name;
+       unsigned mask_bitfield;
+} mask_flags[] = {
+       {"allocate", YAFFS_TRACE_ALLOCATE}, 
+       {"always", YAFFS_TRACE_ALWAYS},
+       {"background", YAFFS_TRACE_BACKGROUND},
+       {"bad_blocks", YAFFS_TRACE_BAD_BLOCKS},
+       {"buffers", YAFFS_TRACE_BUFFERS},
+       {"bug", YAFFS_TRACE_BUG},
+       {"checkpt", YAFFS_TRACE_CHECKPOINT},
+       {"deletion", YAFFS_TRACE_DELETION},
+       {"erase", YAFFS_TRACE_ERASE},
+       {"error", YAFFS_TRACE_ERROR},
+       {"gc_detail", YAFFS_TRACE_GC_DETAIL},
+       {"gc", YAFFS_TRACE_GC},
+       {"lock", YAFFS_TRACE_LOCK},
+       {"mtd", YAFFS_TRACE_MTD},
+       {"nandaccess", YAFFS_TRACE_NANDACCESS},
+       {"os", YAFFS_TRACE_OS},
+       {"scan_debug", YAFFS_TRACE_SCAN_DEBUG},
+       {"scan", YAFFS_TRACE_SCAN},
+       {"mount", YAFFS_TRACE_MOUNT},
+       {"tracing", YAFFS_TRACE_TRACING},
+       {"sync", YAFFS_TRACE_SYNC},
+       {"write", YAFFS_TRACE_WRITE},
+       {"verify", YAFFS_TRACE_VERIFY},
+       {"verify_nand", YAFFS_TRACE_VERIFY_NAND},
+       {"verify_full", YAFFS_TRACE_VERIFY_FULL},
+       {"verify_all", YAFFS_TRACE_VERIFY_ALL},
+       {"all", 0xffffffff},
+       {"none", 0},
+       {NULL, 0},
+};
+
+#define MAX_MASK_NAME_LENGTH 40
+static int yaffs_proc_write_trace_options(struct file *file, const char *buf,
+                                         unsigned long count, void *data)
+{
+       unsigned rg = 0, mask_bitfield;
+       char *end;
+       char *mask_name;
+       const char *x;
+       char substring[MAX_MASK_NAME_LENGTH + 1];
+       int i;
+       int done = 0;
+       int add, len = 0;
+       int pos = 0;
+
+       rg = yaffs_trace_mask;
+
+       while (!done && (pos < count)) {
+               done = 1;
+               while ((pos < count) && isspace(buf[pos]))
+                       pos++;
+
+               switch (buf[pos]) {
+               case '+':
+               case '-':
+               case '=':
+                       add = buf[pos];
+                       pos++;
+                       break;
+
+               default:
+                       add = ' ';
+                       break;
+               }
+               mask_name = NULL;
+
+               mask_bitfield = simple_strtoul(buf + pos, &end, 0);
+
+               if (end > buf + pos) {
+                       mask_name = "numeral";
+                       len = end - (buf + pos);
+                       pos += len;
+                       done = 0;
+               } else {
+                       for (x = buf + pos, i = 0;
+                            (*x == '_' || (*x >= 'a' && *x <= 'z')) &&
+                            i < MAX_MASK_NAME_LENGTH; x++, i++, pos++)
+                               substring[i] = *x;
+                       substring[i] = '\0';
+
+                       for (i = 0; mask_flags[i].mask_name != NULL; i++) {
+                               if (strcmp(substring, mask_flags[i].mask_name)
+                                   == 0) {
+                                       mask_name = mask_flags[i].mask_name;
+                                       mask_bitfield =
+                                           mask_flags[i].mask_bitfield;
+                                       done = 0;
+                                       break;
+                               }
+                       }
+               }
+
+               if (mask_name != NULL) {
+                       done = 0;
+                       switch (add) {
+                       case '-':
+                               rg &= ~mask_bitfield;
+                               break;
+                       case '+':
+                               rg |= mask_bitfield;
+                               break;
+                       case '=':
+                               rg = mask_bitfield;
+                               break;
+                       default:
+                               rg |= mask_bitfield;
+                               break;
+                       }
+               }
+       }
+
+       yaffs_trace_mask = rg | YAFFS_TRACE_ALWAYS;
+
+       printk(KERN_DEBUG "new trace = 0x%08X\n", yaffs_trace_mask);
+
+       if (rg & YAFFS_TRACE_ALWAYS) {
+               for (i = 0; mask_flags[i].mask_name != NULL; i++) {
+                       char flag;
+                       flag = ((rg & mask_flags[i].mask_bitfield) ==
+                               mask_flags[i].mask_bitfield) ? '+' : '-';
+                       printk(KERN_DEBUG "%c%s\n", flag,
+                              mask_flags[i].mask_name);
+               }
+       }
+
+       return count;
+}
+
+static int yaffs_proc_write(struct file *file, const char *buf,
+                           unsigned long count, void *data)
+{
+       return yaffs_proc_write_trace_options(file, buf, count, data);
+}
+
+/* Stuff to handle installation of file systems */
+struct file_system_to_install {
+       struct file_system_type *fst;
+       int installed;
+};
+
+static struct file_system_to_install fs_to_install[] = {
+       {&yaffs_fs_type, 0},
+       {&yaffs2_fs_type, 0},
+       {NULL, 0}
+};
+
+static int __init init_yaffs_fs(void)
+{
+       int error = 0;
+       struct file_system_to_install *fsinst;
+
+       yaffs_trace(YAFFS_TRACE_ALWAYS,
+               "yaffs built " __DATE__ " " __TIME__ " Installing.");
+
+#ifdef CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED
+       yaffs_trace(YAFFS_TRACE_ALWAYS,
+               "\n\nYAFFS-WARNING CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED selected.\n\n\n");
+#endif
+
+       mutex_init(&yaffs_context_lock);
+
+       /* Install the proc_fs entries */
+       my_proc_entry = create_proc_entry("yaffs",
+                                         S_IRUGO | S_IFREG, YPROC_ROOT);
+
+       if (my_proc_entry) {
+               my_proc_entry->write_proc = yaffs_proc_write;
+               my_proc_entry->read_proc = yaffs_proc_read;
+               my_proc_entry->data = NULL;
+       } else {
+               return -ENOMEM;
+        }
+
+
+       /* Now add the file system entries */
+
+       fsinst = fs_to_install;
+
+       while (fsinst->fst && !error) {
+               error = register_filesystem(fsinst->fst);
+               if (!error)
+                       fsinst->installed = 1;
+               fsinst++;
+       }
+
+       /* Any errors? uninstall  */
+       if (error) {
+               fsinst = fs_to_install;
+
+               while (fsinst->fst) {
+                       if (fsinst->installed) {
+                               unregister_filesystem(fsinst->fst);
+                               fsinst->installed = 0;
+                       }
+                       fsinst++;
+               }
+       }
+
+       return error;
+}
+
+static void __exit exit_yaffs_fs(void)
+{
+
+       struct file_system_to_install *fsinst;
+
+       yaffs_trace(YAFFS_TRACE_ALWAYS,
+               "yaffs built " __DATE__ " " __TIME__ " removing.");
+
+       remove_proc_entry("yaffs", YPROC_ROOT);
+
+       fsinst = fs_to_install;
+
+       while (fsinst->fst) {
+               if (fsinst->installed) {
+                       unregister_filesystem(fsinst->fst);
+                       fsinst->installed = 0;
+               }
+               fsinst++;
+       }
+}
+
+module_init(init_yaffs_fs)
+    module_exit(exit_yaffs_fs)
+
+    MODULE_DESCRIPTION("YAFFS2 - a NAND specific flash file system");
+MODULE_AUTHOR("Charles Manning, Aleph One Ltd., 2002-2010");
+MODULE_LICENSE("GPL");
diff --git a/fs/yaffs2/yaffs_yaffs1.c b/fs/yaffs2/yaffs_yaffs1.c
new file mode 100644 (file)
index 0000000..9eb6030
--- /dev/null
@@ -0,0 +1,433 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_yaffs1.h"
+#include "yportenv.h"
+#include "yaffs_trace.h"
+#include "yaffs_bitmap.h"
+#include "yaffs_getblockinfo.h"
+#include "yaffs_nand.h"
+#include "yaffs_attribs.h"
+
+int yaffs1_scan(struct yaffs_dev *dev)
+{
+       struct yaffs_ext_tags tags;
+       int blk;
+       int result;
+
+       int chunk;
+       int c;
+       int deleted;
+       enum yaffs_block_state state;
+       struct yaffs_obj *hard_list = NULL;
+       struct yaffs_block_info *bi;
+       u32 seq_number;
+       struct yaffs_obj_hdr *oh;
+       struct yaffs_obj *in;
+       struct yaffs_obj *parent;
+
+       int alloc_failed = 0;
+
+       struct yaffs_shadow_fixer *shadow_fixers = NULL;
+
+       u8 *chunk_data;
+
+       yaffs_trace(YAFFS_TRACE_SCAN,
+               "yaffs1_scan starts  intstartblk %d intendblk %d...",
+               dev->internal_start_block, dev->internal_end_block);
+
+       chunk_data = yaffs_get_temp_buffer(dev, __LINE__);
+
+       dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
+
+       /* Scan all the blocks to determine their state */
+       bi = dev->block_info;
+       for (blk = dev->internal_start_block; blk <= dev->internal_end_block;
+            blk++) {
+               yaffs_clear_chunk_bits(dev, blk);
+               bi->pages_in_use = 0;
+               bi->soft_del_pages = 0;
+
+               yaffs_query_init_block_state(dev, blk, &state, &seq_number);
+
+               bi->block_state = state;
+               bi->seq_number = seq_number;
+
+               if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
+                       bi->block_state = state = YAFFS_BLOCK_STATE_DEAD;
+
+               yaffs_trace(YAFFS_TRACE_SCAN_DEBUG,
+                       "Block scanning block %d state %d seq %d",
+                       blk, state, seq_number);
+
+               if (state == YAFFS_BLOCK_STATE_DEAD) {
+                       yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
+                               "block %d is bad", blk);
+               } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
+                       yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "Block empty ");
+                       dev->n_erased_blocks++;
+                       dev->n_free_chunks += dev->param.chunks_per_block;
+               }
+               bi++;
+       }
+
+       /* For each block.... */
+       for (blk = dev->internal_start_block;
+            !alloc_failed && blk <= dev->internal_end_block; blk++) {
+
+               cond_resched();
+
+               bi = yaffs_get_block_info(dev, blk);
+               state = bi->block_state;
+
+               deleted = 0;
+
+               /* For each chunk in each block that needs scanning.... */
+               for (c = 0; !alloc_failed && c < dev->param.chunks_per_block &&
+                    state == YAFFS_BLOCK_STATE_NEEDS_SCANNING; c++) {
+                       /* Read the tags and decide what to do */
+                       chunk = blk * dev->param.chunks_per_block + c;
+
+                       result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL,
+                                                         &tags);
+
+                       /* Let's have a good look at this chunk... */
+
+                       if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED
+                           || tags.is_deleted) {
+                               /* YAFFS1 only...
+                                * A deleted chunk
+                                */
+                               deleted++;
+                               dev->n_free_chunks++;
+                               /*T((" %d %d deleted\n",blk,c)); */
+                       } else if (!tags.chunk_used) {
+                               /* An unassigned chunk in the block
+                                * This means that either the block is empty or
+                                * this is the one being allocated from
+                                */
+
+                               if (c == 0) {
+                                       /* We're looking at the first chunk in the block so the block is unused */
+                                       state = YAFFS_BLOCK_STATE_EMPTY;
+                                       dev->n_erased_blocks++;
+                               } else {
+                                       /* this is the block being allocated from */
+                                       yaffs_trace(YAFFS_TRACE_SCAN,
+                                               " Allocating from %d %d",
+                                               blk, c);
+                                       state = YAFFS_BLOCK_STATE_ALLOCATING;
+                                       dev->alloc_block = blk;
+                                       dev->alloc_page = c;
+                                       dev->alloc_block_finder = blk;
+                                       /* Set block finder here to encourage the allocator to go forth from here. */
+
+                               }
+
+                               dev->n_free_chunks +=
+                                   (dev->param.chunks_per_block - c);
+                       } else if (tags.chunk_id > 0) {
+                               /* chunk_id > 0 so it is a data chunk... */
+                               unsigned int endpos;
+
+                               yaffs_set_chunk_bit(dev, blk, c);
+                               bi->pages_in_use++;
+
+                               in = yaffs_find_or_create_by_number(dev,
+                                                                   tags.obj_id,
+                                                                   YAFFS_OBJECT_TYPE_FILE);
+                               /* PutChunkIntoFile checks for a clash (two data chunks with
+                                * the same chunk_id).
+                                */
+
+                               if (!in)
+                                       alloc_failed = 1;
+
+                               if (in) {
+                                       if (!yaffs_put_chunk_in_file
+                                           (in, tags.chunk_id, chunk, 1))
+                                               alloc_failed = 1;
+                               }
+
+                               endpos =
+                                   (tags.chunk_id -
+                                    1) * dev->data_bytes_per_chunk +
+                                   tags.n_bytes;
+                               if (in
+                                   && in->variant_type ==
+                                   YAFFS_OBJECT_TYPE_FILE
+                                   && in->variant.file_variant.scanned_size <
+                                   endpos) {
+                                       in->variant.file_variant.scanned_size =
+                                           endpos;
+                                       if (!dev->param.use_header_file_size) {
+                                               in->variant.
+                                                   file_variant.file_size =
+                                                   in->variant.
+                                                   file_variant.scanned_size;
+                                       }
+
+                               }
+                               /* T((" %d %d data %d %d\n",blk,c,tags.obj_id,tags.chunk_id));   */
+                       } else {
+                               /* chunk_id == 0, so it is an ObjectHeader.
+                                * Thus, we read in the object header and make the object
+                                */
+                               yaffs_set_chunk_bit(dev, blk, c);
+                               bi->pages_in_use++;
+
+                               result = yaffs_rd_chunk_tags_nand(dev, chunk,
+                                                                 chunk_data,
+                                                                 NULL);
+
+                               oh = (struct yaffs_obj_hdr *)chunk_data;
+
+                               in = yaffs_find_by_number(dev, tags.obj_id);
+                               if (in && in->variant_type != oh->type) {
+                                       /* This should not happen, but somehow
+                                        * Wev'e ended up with an obj_id that has been reused but not yet
+                                        * deleted, and worse still it has changed type. Delete the old object.
+                                        */
+
+                                       yaffs_del_obj(in);
+
+                                       in = 0;
+                               }
+
+                               in = yaffs_find_or_create_by_number(dev,
+                                                                   tags.obj_id,
+                                                                   oh->type);
+
+                               if (!in)
+                                       alloc_failed = 1;
+
+                               if (in && oh->shadows_obj > 0) {
+
+                                       struct yaffs_shadow_fixer *fixer;
+                                       fixer =
+                                               kmalloc(sizeof
+                                               (struct yaffs_shadow_fixer),
+                                               GFP_NOFS);
+                                       if (fixer) {
+                                               fixer->next = shadow_fixers;
+                                               shadow_fixers = fixer;
+                                               fixer->obj_id = tags.obj_id;
+                                               fixer->shadowed_id =
+                                                   oh->shadows_obj;
+                                               yaffs_trace(YAFFS_TRACE_SCAN,
+                                                       " Shadow fixer: %d shadows %d",
+                                                       fixer->obj_id,
+                                                       fixer->shadowed_id);
+
+                                       }
+
+                               }
+
+                               if (in && in->valid) {
+                                       /* We have already filled this one. We have a duplicate and need to resolve it. */
+
+                                       unsigned existing_serial = in->serial;
+                                       unsigned new_serial =
+                                           tags.serial_number;
+
+                                       if (((existing_serial + 1) & 3) ==
+                                           new_serial) {
+                                               /* Use new one - destroy the exisiting one */
+                                               yaffs_chunk_del(dev,
+                                                               in->hdr_chunk,
+                                                               1, __LINE__);
+                                               in->valid = 0;
+                                       } else {
+                                               /* Use existing - destroy this one. */
+                                               yaffs_chunk_del(dev, chunk, 1,
+                                                               __LINE__);
+                                       }
+                               }
+
+                               if (in && !in->valid &&
+                                   (tags.obj_id == YAFFS_OBJECTID_ROOT ||
+                                    tags.obj_id ==
+                                    YAFFS_OBJECTID_LOSTNFOUND)) {
+                                       /* We only load some info, don't fiddle with directory structure */
+                                       in->valid = 1;
+                                       in->variant_type = oh->type;
+
+                                       in->yst_mode = oh->yst_mode;
+                                       yaffs_load_attribs(in, oh);
+                                       in->hdr_chunk = chunk;
+                                       in->serial = tags.serial_number;
+
+                               } else if (in && !in->valid) {
+                                       /* we need to load this info */
+
+                                       in->valid = 1;
+                                       in->variant_type = oh->type;
+
+                                       in->yst_mode = oh->yst_mode;
+                                       yaffs_load_attribs(in, oh);
+                                       in->hdr_chunk = chunk;
+                                       in->serial = tags.serial_number;
+
+                                       yaffs_set_obj_name_from_oh(in, oh);
+                                       in->dirty = 0;
+
+                                       /* directory stuff...
+                                        * hook up to parent
+                                        */
+
+                                       parent =
+                                           yaffs_find_or_create_by_number
+                                           (dev, oh->parent_obj_id,
+                                            YAFFS_OBJECT_TYPE_DIRECTORY);
+                                       if (!parent)
+                                               alloc_failed = 1;
+                                       if (parent && parent->variant_type ==
+                                           YAFFS_OBJECT_TYPE_UNKNOWN) {
+                                               /* Set up as a directory */
+                                               parent->variant_type =
+                                                   YAFFS_OBJECT_TYPE_DIRECTORY;
+                                               INIT_LIST_HEAD(&parent->
+                                                              variant.dir_variant.children);
+                                       } else if (!parent
+                                                  || parent->variant_type !=
+                                                  YAFFS_OBJECT_TYPE_DIRECTORY) {
+                                               /* Hoosterman, another problem....
+                                                * We're trying to use a non-directory as a directory
+                                                */
+
+                                               yaffs_trace(YAFFS_TRACE_ERROR,
+                                                       "yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
+                                                       );
+                                               parent = dev->lost_n_found;
+                                       }
+
+                                       yaffs_add_obj_to_dir(parent, in);
+
+                                       if (0 && (parent == dev->del_dir ||
+                                                 parent ==
+                                                 dev->unlinked_dir)) {
+                                               in->deleted = 1;        /* If it is unlinked at start up then it wants deleting */
+                                               dev->n_deleted_files++;
+                                       }
+                                       /* Note re hardlinks.
+                                        * Since we might scan a hardlink before its equivalent object is scanned
+                                        * we put them all in a list.
+                                        * After scanning is complete, we should have all the objects, so we run through this
+                                        * list and fix up all the chains.
+                                        */
+
+                                       switch (in->variant_type) {
+                                       case YAFFS_OBJECT_TYPE_UNKNOWN:
+                                               /* Todo got a problem */
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_FILE:
+                                               if (dev->param.
+                                                   use_header_file_size)
+
+                                                       in->variant.
+                                                           file_variant.file_size
+                                                           = oh->file_size;
+
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_HARDLINK:
+                                               in->variant.
+                                                   hardlink_variant.equiv_id =
+                                                   oh->equiv_id;
+                                               in->hard_links.next =
+                                                   (struct list_head *)
+                                                   hard_list;
+                                               hard_list = in;
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_DIRECTORY:
+                                               /* Do nothing */
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_SPECIAL:
+                                               /* Do nothing */
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_SYMLINK:
+                                               in->variant.symlink_variant.
+                                                   alias =
+                                                   yaffs_clone_str(oh->alias);
+                                               if (!in->variant.
+                                                   symlink_variant.alias)
+                                                       alloc_failed = 1;
+                                               break;
+                                       }
+
+                               }
+                       }
+               }
+
+               if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
+                       /* If we got this far while scanning, then the block is fully allocated. */
+                       state = YAFFS_BLOCK_STATE_FULL;
+               }
+
+               if (state == YAFFS_BLOCK_STATE_ALLOCATING) {
+                       /* If the block was partially allocated then treat it as fully allocated. */
+                       state = YAFFS_BLOCK_STATE_FULL;
+                       dev->alloc_block = -1;
+               }
+
+               bi->block_state = state;
+
+               /* Now let's see if it was dirty */
+               if (bi->pages_in_use == 0 &&
+                   !bi->has_shrink_hdr &&
+                   bi->block_state == YAFFS_BLOCK_STATE_FULL) {
+                       yaffs_block_became_dirty(dev, blk);
+               }
+
+       }
+
+       /* Ok, we've done all the scanning.
+        * Fix up the hard link chains.
+        * We should now have scanned all the objects, now it's time to add these
+        * hardlinks.
+        */
+
+       yaffs_link_fixup(dev, hard_list);
+
+       /* Fix up any shadowed objects */
+       {
+               struct yaffs_shadow_fixer *fixer;
+               struct yaffs_obj *obj;
+
+               while (shadow_fixers) {
+                       fixer = shadow_fixers;
+                       shadow_fixers = fixer->next;
+                       /* Complete the rename transaction by deleting the shadowed object
+                        * then setting the object header to unshadowed.
+                        */
+                       obj = yaffs_find_by_number(dev, fixer->shadowed_id);
+                       if (obj)
+                               yaffs_del_obj(obj);
+
+                       obj = yaffs_find_by_number(dev, fixer->obj_id);
+
+                       if (obj)
+                               yaffs_update_oh(obj, NULL, 1, 0, 0, NULL);
+
+                       kfree(fixer);
+               }
+       }
+
+       yaffs_release_temp_buffer(dev, chunk_data, __LINE__);
+
+       if (alloc_failed)
+               return YAFFS_FAIL;
+
+       yaffs_trace(YAFFS_TRACE_SCAN, "yaffs1_scan ends");
+
+       return YAFFS_OK;
+}
diff --git a/fs/yaffs2/yaffs_yaffs1.h b/fs/yaffs2/yaffs_yaffs1.h
new file mode 100644 (file)
index 0000000..db23e04
--- /dev/null
@@ -0,0 +1,22 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_YAFFS1_H__
+#define __YAFFS_YAFFS1_H__
+
+#include "yaffs_guts.h"
+int yaffs1_scan(struct yaffs_dev *dev);
+
+#endif
diff --git a/fs/yaffs2/yaffs_yaffs2.c b/fs/yaffs2/yaffs_yaffs2.c
new file mode 100644 (file)
index 0000000..33397af
--- /dev/null
@@ -0,0 +1,1598 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_guts.h"
+#include "yaffs_trace.h"
+#include "yaffs_yaffs2.h"
+#include "yaffs_checkptrw.h"
+#include "yaffs_bitmap.h"
+#include "yaffs_nand.h"
+#include "yaffs_getblockinfo.h"
+#include "yaffs_verify.h"
+#include "yaffs_attribs.h"
+
+/*
+ * Checkpoints are really no benefit on very small partitions.
+ *
+ * To save space on small partitions don't bother with checkpoints unless
+ * the partition is at least this big.
+ */
+#define YAFFS_CHECKPOINT_MIN_BLOCKS 60
+
+#define YAFFS_SMALL_HOLE_THRESHOLD 4
+
+/*
+ * Oldest Dirty Sequence Number handling.
+ */
+
+/* yaffs_calc_oldest_dirty_seq()
+ * yaffs2_find_oldest_dirty_seq()
+ * Calculate the oldest dirty sequence number if we don't know it.
+ */
+void yaffs_calc_oldest_dirty_seq(struct yaffs_dev *dev)
+{
+       int i;
+       unsigned seq;
+       unsigned block_no = 0;
+       struct yaffs_block_info *b;
+
+       if (!dev->param.is_yaffs2)
+               return;
+
+       /* Find the oldest dirty sequence number. */
+       seq = dev->seq_number + 1;
+       b = dev->block_info;
+       for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
+               if (b->block_state == YAFFS_BLOCK_STATE_FULL &&
+                   (b->pages_in_use - b->soft_del_pages) <
+                   dev->param.chunks_per_block && b->seq_number < seq) {
+                       seq = b->seq_number;
+                       block_no = i;
+               }
+               b++;
+       }
+
+       if (block_no) {
+               dev->oldest_dirty_seq = seq;
+               dev->oldest_dirty_block = block_no;
+       }
+
+}
+
+void yaffs2_find_oldest_dirty_seq(struct yaffs_dev *dev)
+{
+       if (!dev->param.is_yaffs2)
+               return;
+
+       if (!dev->oldest_dirty_seq)
+               yaffs_calc_oldest_dirty_seq(dev);
+}
+
+/*
+ * yaffs_clear_oldest_dirty_seq()
+ * Called when a block is erased or marked bad. (ie. when its seq_number
+ * becomes invalid). If the value matches the oldest then we clear 
+ * dev->oldest_dirty_seq to force its recomputation.
+ */
+void yaffs2_clear_oldest_dirty_seq(struct yaffs_dev *dev,
+                                  struct yaffs_block_info *bi)
+{
+
+       if (!dev->param.is_yaffs2)
+               return;
+
+       if (!bi || bi->seq_number == dev->oldest_dirty_seq) {
+               dev->oldest_dirty_seq = 0;
+               dev->oldest_dirty_block = 0;
+       }
+}
+
+/*
+ * yaffs2_update_oldest_dirty_seq()
+ * Update the oldest dirty sequence number whenever we dirty a block.
+ * Only do this if the oldest_dirty_seq is actually being tracked.
+ */
+void yaffs2_update_oldest_dirty_seq(struct yaffs_dev *dev, unsigned block_no,
+                                   struct yaffs_block_info *bi)
+{
+       if (!dev->param.is_yaffs2)
+               return;
+
+       if (dev->oldest_dirty_seq) {
+               if (dev->oldest_dirty_seq > bi->seq_number) {
+                       dev->oldest_dirty_seq = bi->seq_number;
+                       dev->oldest_dirty_block = block_no;
+               }
+       }
+}
+
+int yaffs_block_ok_for_gc(struct yaffs_dev *dev, struct yaffs_block_info *bi)
+{
+
+       if (!dev->param.is_yaffs2)
+               return 1;       /* disqualification only applies to yaffs2. */
+
+       if (!bi->has_shrink_hdr)
+               return 1;       /* can gc */
+
+       yaffs2_find_oldest_dirty_seq(dev);
+
+       /* Can't do gc of this block if there are any blocks older than this one that have
+        * discarded pages.
+        */
+       return (bi->seq_number <= dev->oldest_dirty_seq);
+}
+
+/*
+ * yaffs2_find_refresh_block()
+ * periodically finds the oldest full block by sequence number for refreshing.
+ * Only for yaffs2.
+ */
+u32 yaffs2_find_refresh_block(struct yaffs_dev * dev)
+{
+       u32 b;
+
+       u32 oldest = 0;
+       u32 oldest_seq = 0;
+
+       struct yaffs_block_info *bi;
+
+       if (!dev->param.is_yaffs2)
+               return oldest;
+
+       /*
+        * If refresh period < 10 then refreshing is disabled.
+        */
+       if (dev->param.refresh_period < 10)
+               return oldest;
+
+       /*
+        * Fix broken values.
+        */
+       if (dev->refresh_skip > dev->param.refresh_period)
+               dev->refresh_skip = dev->param.refresh_period;
+
+       if (dev->refresh_skip > 0)
+               return oldest;
+
+       /*
+        * Refresh skip is now zero.
+        * We'll do a refresh this time around....
+        * Update the refresh skip and find the oldest block.
+        */
+       dev->refresh_skip = dev->param.refresh_period;
+       dev->refresh_count++;
+       bi = dev->block_info;
+       for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
+
+               if (bi->block_state == YAFFS_BLOCK_STATE_FULL) {
+
+                       if (oldest < 1 || bi->seq_number < oldest_seq) {
+                               oldest = b;
+                               oldest_seq = bi->seq_number;
+                       }
+               }
+               bi++;
+       }
+
+       if (oldest > 0) {
+               yaffs_trace(YAFFS_TRACE_GC,
+                       "GC refresh count %d selected block %d with seq_number %d",
+                       dev->refresh_count, oldest, oldest_seq);
+       }
+
+       return oldest;
+}
+
+int yaffs2_checkpt_required(struct yaffs_dev *dev)
+{
+       int nblocks;
+
+       if (!dev->param.is_yaffs2)
+               return 0;
+
+       nblocks = dev->internal_end_block - dev->internal_start_block + 1;
+
+       return !dev->param.skip_checkpt_wr &&
+           !dev->read_only && (nblocks >= YAFFS_CHECKPOINT_MIN_BLOCKS);
+}
+
+int yaffs_calc_checkpt_blocks_required(struct yaffs_dev *dev)
+{
+       int retval;
+
+       if (!dev->param.is_yaffs2)
+               return 0;
+
+       if (!dev->checkpoint_blocks_required && yaffs2_checkpt_required(dev)) {
+               /* Not a valid value so recalculate */
+               int n_bytes = 0;
+               int n_blocks;
+               int dev_blocks =
+                   (dev->param.end_block - dev->param.start_block + 1);
+
+               n_bytes += sizeof(struct yaffs_checkpt_validity);
+               n_bytes += sizeof(struct yaffs_checkpt_dev);
+               n_bytes += dev_blocks * sizeof(struct yaffs_block_info);
+               n_bytes += dev_blocks * dev->chunk_bit_stride;
+               n_bytes +=
+                   (sizeof(struct yaffs_checkpt_obj) +
+                    sizeof(u32)) * (dev->n_obj);
+               n_bytes += (dev->tnode_size + sizeof(u32)) * (dev->n_tnodes);
+               n_bytes += sizeof(struct yaffs_checkpt_validity);
+               n_bytes += sizeof(u32); /* checksum */
+
+               /* Round up and add 2 blocks to allow for some bad blocks, so add 3 */
+
+               n_blocks =
+                   (n_bytes /
+                    (dev->data_bytes_per_chunk *
+                     dev->param.chunks_per_block)) + 3;
+
+               dev->checkpoint_blocks_required = n_blocks;
+       }
+
+       retval = dev->checkpoint_blocks_required - dev->blocks_in_checkpt;
+       if (retval < 0)
+               retval = 0;
+       return retval;
+}
+
+/*--------------------- Checkpointing --------------------*/
+
+static int yaffs2_wr_checkpt_validity_marker(struct yaffs_dev *dev, int head)
+{
+       struct yaffs_checkpt_validity cp;
+
+       memset(&cp, 0, sizeof(cp));
+
+       cp.struct_type = sizeof(cp);
+       cp.magic = YAFFS_MAGIC;
+       cp.version = YAFFS_CHECKPOINT_VERSION;
+       cp.head = (head) ? 1 : 0;
+
+       return (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp)) ? 1 : 0;
+}
+
+static int yaffs2_rd_checkpt_validity_marker(struct yaffs_dev *dev, int head)
+{
+       struct yaffs_checkpt_validity cp;
+       int ok;
+
+       ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
+
+       if (ok)
+               ok = (cp.struct_type == sizeof(cp)) &&
+                   (cp.magic == YAFFS_MAGIC) &&
+                   (cp.version == YAFFS_CHECKPOINT_VERSION) &&
+                   (cp.head == ((head) ? 1 : 0));
+       return ok ? 1 : 0;
+}
+
+static void yaffs2_dev_to_checkpt_dev(struct yaffs_checkpt_dev *cp,
+                                     struct yaffs_dev *dev)
+{
+       cp->n_erased_blocks = dev->n_erased_blocks;
+       cp->alloc_block = dev->alloc_block;
+       cp->alloc_page = dev->alloc_page;
+       cp->n_free_chunks = dev->n_free_chunks;
+
+       cp->n_deleted_files = dev->n_deleted_files;
+       cp->n_unlinked_files = dev->n_unlinked_files;
+       cp->n_bg_deletions = dev->n_bg_deletions;
+       cp->seq_number = dev->seq_number;
+
+}
+
+static void yaffs_checkpt_dev_to_dev(struct yaffs_dev *dev,
+                                    struct yaffs_checkpt_dev *cp)
+{
+       dev->n_erased_blocks = cp->n_erased_blocks;
+       dev->alloc_block = cp->alloc_block;
+       dev->alloc_page = cp->alloc_page;
+       dev->n_free_chunks = cp->n_free_chunks;
+
+       dev->n_deleted_files = cp->n_deleted_files;
+       dev->n_unlinked_files = cp->n_unlinked_files;
+       dev->n_bg_deletions = cp->n_bg_deletions;
+       dev->seq_number = cp->seq_number;
+}
+
+static int yaffs2_wr_checkpt_dev(struct yaffs_dev *dev)
+{
+       struct yaffs_checkpt_dev cp;
+       u32 n_bytes;
+       u32 n_blocks =
+           (dev->internal_end_block - dev->internal_start_block + 1);
+
+       int ok;
+
+       /* Write device runtime values */
+       yaffs2_dev_to_checkpt_dev(&cp, dev);
+       cp.struct_type = sizeof(cp);
+
+       ok = (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp));
+
+       /* Write block info */
+       if (ok) {
+               n_bytes = n_blocks * sizeof(struct yaffs_block_info);
+               ok = (yaffs2_checkpt_wr(dev, dev->block_info, n_bytes) ==
+                     n_bytes);
+       }
+
+       /* Write chunk bits */
+       if (ok) {
+               n_bytes = n_blocks * dev->chunk_bit_stride;
+               ok = (yaffs2_checkpt_wr(dev, dev->chunk_bits, n_bytes) ==
+                     n_bytes);
+       }
+       return ok ? 1 : 0;
+
+}
+
+static int yaffs2_rd_checkpt_dev(struct yaffs_dev *dev)
+{
+       struct yaffs_checkpt_dev cp;
+       u32 n_bytes;
+       u32 n_blocks =
+           (dev->internal_end_block - dev->internal_start_block + 1);
+
+       int ok;
+
+       ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
+       if (!ok)
+               return 0;
+
+       if (cp.struct_type != sizeof(cp))
+               return 0;
+
+       yaffs_checkpt_dev_to_dev(dev, &cp);
+
+       n_bytes = n_blocks * sizeof(struct yaffs_block_info);
+
+       ok = (yaffs2_checkpt_rd(dev, dev->block_info, n_bytes) == n_bytes);
+
+       if (!ok)
+               return 0;
+       n_bytes = n_blocks * dev->chunk_bit_stride;
+
+       ok = (yaffs2_checkpt_rd(dev, dev->chunk_bits, n_bytes) == n_bytes);
+
+       return ok ? 1 : 0;
+}
+
+static void yaffs2_obj_checkpt_obj(struct yaffs_checkpt_obj *cp,
+                                  struct yaffs_obj *obj)
+{
+
+       cp->obj_id = obj->obj_id;
+       cp->parent_id = (obj->parent) ? obj->parent->obj_id : 0;
+       cp->hdr_chunk = obj->hdr_chunk;
+       cp->variant_type = obj->variant_type;
+       cp->deleted = obj->deleted;
+       cp->soft_del = obj->soft_del;
+       cp->unlinked = obj->unlinked;
+       cp->fake = obj->fake;
+       cp->rename_allowed = obj->rename_allowed;
+       cp->unlink_allowed = obj->unlink_allowed;
+       cp->serial = obj->serial;
+       cp->n_data_chunks = obj->n_data_chunks;
+
+       if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
+               cp->size_or_equiv_obj = obj->variant.file_variant.file_size;
+       else if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK)
+               cp->size_or_equiv_obj = obj->variant.hardlink_variant.equiv_id;
+}
+
+static int taffs2_checkpt_obj_to_obj(struct yaffs_obj *obj,
+                                    struct yaffs_checkpt_obj *cp)
+{
+
+       struct yaffs_obj *parent;
+
+       if (obj->variant_type != cp->variant_type) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                       "Checkpoint read object %d type %d chunk %d does not match existing object type %d",
+                       cp->obj_id, cp->variant_type, cp->hdr_chunk,
+                       obj->variant_type);
+               return 0;
+       }
+
+       obj->obj_id = cp->obj_id;
+
+       if (cp->parent_id)
+               parent = yaffs_find_or_create_by_number(obj->my_dev,
+                                                       cp->parent_id,
+                                                       YAFFS_OBJECT_TYPE_DIRECTORY);
+       else
+               parent = NULL;
+
+       if (parent) {
+               if (parent->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+                       yaffs_trace(YAFFS_TRACE_ALWAYS,
+                               "Checkpoint read object %d parent %d type %d chunk %d Parent type, %d, not directory",
+                               cp->obj_id, cp->parent_id,
+                               cp->variant_type, cp->hdr_chunk,
+                               parent->variant_type);
+                       return 0;
+               }
+               yaffs_add_obj_to_dir(parent, obj);
+       }
+
+       obj->hdr_chunk = cp->hdr_chunk;
+       obj->variant_type = cp->variant_type;
+       obj->deleted = cp->deleted;
+       obj->soft_del = cp->soft_del;
+       obj->unlinked = cp->unlinked;
+       obj->fake = cp->fake;
+       obj->rename_allowed = cp->rename_allowed;
+       obj->unlink_allowed = cp->unlink_allowed;
+       obj->serial = cp->serial;
+       obj->n_data_chunks = cp->n_data_chunks;
+
+       if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
+               obj->variant.file_variant.file_size = cp->size_or_equiv_obj;
+       else if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK)
+               obj->variant.hardlink_variant.equiv_id = cp->size_or_equiv_obj;
+
+       if (obj->hdr_chunk > 0)
+               obj->lazy_loaded = 1;
+       return 1;
+}
+
+static int yaffs2_checkpt_tnode_worker(struct yaffs_obj *in,
+                                      struct yaffs_tnode *tn, u32 level,
+                                      int chunk_offset)
+{
+       int i;
+       struct yaffs_dev *dev = in->my_dev;
+       int ok = 1;
+
+       if (tn) {
+               if (level > 0) {
+
+                       for (i = 0; i < YAFFS_NTNODES_INTERNAL && ok; i++) {
+                               if (tn->internal[i]) {
+                                       ok = yaffs2_checkpt_tnode_worker(in,
+                                                                        tn->
+                                                                        internal
+                                                                        [i],
+                                                                        level -
+                                                                        1,
+                                                                        (chunk_offset
+                                                                         <<
+                                                                         YAFFS_TNODES_INTERNAL_BITS)
+                                                                        + i);
+                               }
+                       }
+               } else if (level == 0) {
+                       u32 base_offset =
+                           chunk_offset << YAFFS_TNODES_LEVEL0_BITS;
+                       ok = (yaffs2_checkpt_wr
+                             (dev, &base_offset,
+                              sizeof(base_offset)) == sizeof(base_offset));
+                       if (ok)
+                               ok = (yaffs2_checkpt_wr
+                                     (dev, tn,
+                                      dev->tnode_size) == dev->tnode_size);
+               }
+       }
+
+       return ok;
+
+}
+
+static int yaffs2_wr_checkpt_tnodes(struct yaffs_obj *obj)
+{
+       u32 end_marker = ~0;
+       int ok = 1;
+
+       if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE) {
+               ok = yaffs2_checkpt_tnode_worker(obj,
+                                                obj->variant.file_variant.top,
+                                                obj->variant.file_variant.
+                                                top_level, 0);
+               if (ok)
+                       ok = (yaffs2_checkpt_wr
+                             (obj->my_dev, &end_marker,
+                              sizeof(end_marker)) == sizeof(end_marker));
+       }
+
+       return ok ? 1 : 0;
+}
+
+static int yaffs2_rd_checkpt_tnodes(struct yaffs_obj *obj)
+{
+       u32 base_chunk;
+       int ok = 1;
+       struct yaffs_dev *dev = obj->my_dev;
+       struct yaffs_file_var *file_stuct_ptr = &obj->variant.file_variant;
+       struct yaffs_tnode *tn;
+       int nread = 0;
+
+       ok = (yaffs2_checkpt_rd(dev, &base_chunk, sizeof(base_chunk)) ==
+             sizeof(base_chunk));
+
+       while (ok && (~base_chunk)) {
+               nread++;
+               /* Read level 0 tnode */
+
+               tn = yaffs_get_tnode(dev);
+               if (tn) {
+                       ok = (yaffs2_checkpt_rd(dev, tn, dev->tnode_size) ==
+                             dev->tnode_size);
+               } else {
+                       ok = 0;
+                }
+
+               if (tn && ok)
+                       ok = yaffs_add_find_tnode_0(dev,
+                                                   file_stuct_ptr,
+                                                   base_chunk, tn) ? 1 : 0;
+
+               if (ok)
+                       ok = (yaffs2_checkpt_rd
+                             (dev, &base_chunk,
+                              sizeof(base_chunk)) == sizeof(base_chunk));
+
+       }
+
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+               "Checkpoint read tnodes %d records, last %d. ok %d",
+               nread, base_chunk, ok);
+
+       return ok ? 1 : 0;
+}
+
+static int yaffs2_wr_checkpt_objs(struct yaffs_dev *dev)
+{
+       struct yaffs_obj *obj;
+       struct yaffs_checkpt_obj cp;
+       int i;
+       int ok = 1;
+       struct list_head *lh;
+
+       /* Iterate through the objects in each hash entry,
+        * dumping them to the checkpointing stream.
+        */
+
+       for (i = 0; ok && i < YAFFS_NOBJECT_BUCKETS; i++) {
+               list_for_each(lh, &dev->obj_bucket[i].list) {
+                       if (lh) {
+                               obj =
+                                   list_entry(lh, struct yaffs_obj, hash_link);
+                               if (!obj->defered_free) {
+                                       yaffs2_obj_checkpt_obj(&cp, obj);
+                                       cp.struct_type = sizeof(cp);
+
+                                       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                                               "Checkpoint write object %d parent %d type %d chunk %d obj addr %p",
+                                               cp.obj_id, cp.parent_id,
+                                               cp.variant_type, cp.hdr_chunk, obj);
+
+                                       ok = (yaffs2_checkpt_wr
+                                             (dev, &cp,
+                                              sizeof(cp)) == sizeof(cp));
+
+                                       if (ok
+                                           && obj->variant_type ==
+                                           YAFFS_OBJECT_TYPE_FILE)
+                                               ok = yaffs2_wr_checkpt_tnodes
+                                                   (obj);
+                               }
+                       }
+               }
+       }
+
+       /* Dump end of list */
+       memset(&cp, 0xFF, sizeof(struct yaffs_checkpt_obj));
+       cp.struct_type = sizeof(cp);
+
+       if (ok)
+               ok = (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp));
+
+       return ok ? 1 : 0;
+}
+
+static int yaffs2_rd_checkpt_objs(struct yaffs_dev *dev)
+{
+       struct yaffs_obj *obj;
+       struct yaffs_checkpt_obj cp;
+       int ok = 1;
+       int done = 0;
+       struct yaffs_obj *hard_list = NULL;
+
+       while (ok && !done) {
+               ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
+               if (cp.struct_type != sizeof(cp)) {
+                       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                               "struct size %d instead of %d ok %d",
+                               cp.struct_type, (int)sizeof(cp), ok);
+                       ok = 0;
+               }
+
+               yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                       "Checkpoint read object %d parent %d type %d chunk %d ",
+                       cp.obj_id, cp.parent_id, cp.variant_type,
+                       cp.hdr_chunk);
+
+               if (ok && cp.obj_id == ~0) {
+                       done = 1;
+               } else if (ok) {
+                       obj =
+                           yaffs_find_or_create_by_number(dev, cp.obj_id,
+                                                          cp.variant_type);
+                       if (obj) {
+                               ok = taffs2_checkpt_obj_to_obj(obj, &cp);
+                               if (!ok)
+                                       break;
+                               if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE) {
+                                       ok = yaffs2_rd_checkpt_tnodes(obj);
+                               } else if (obj->variant_type ==
+                                          YAFFS_OBJECT_TYPE_HARDLINK) {
+                                       obj->hard_links.next =
+                                           (struct list_head *)hard_list;
+                                       hard_list = obj;
+                               }
+                       } else {
+                               ok = 0;
+                        }
+               }
+       }
+
+       if (ok)
+               yaffs_link_fixup(dev, hard_list);
+
+       return ok ? 1 : 0;
+}
+
+static int yaffs2_wr_checkpt_sum(struct yaffs_dev *dev)
+{
+       u32 checkpt_sum;
+       int ok;
+
+       yaffs2_get_checkpt_sum(dev, &checkpt_sum);
+
+       ok = (yaffs2_checkpt_wr(dev, &checkpt_sum, sizeof(checkpt_sum)) ==
+             sizeof(checkpt_sum));
+
+       if (!ok)
+               return 0;
+
+       return 1;
+}
+
+static int yaffs2_rd_checkpt_sum(struct yaffs_dev *dev)
+{
+       u32 checkpt_sum0;
+       u32 checkpt_sum1;
+       int ok;
+
+       yaffs2_get_checkpt_sum(dev, &checkpt_sum0);
+
+       ok = (yaffs2_checkpt_rd(dev, &checkpt_sum1, sizeof(checkpt_sum1)) ==
+             sizeof(checkpt_sum1));
+
+       if (!ok)
+               return 0;
+
+       if (checkpt_sum0 != checkpt_sum1)
+               return 0;
+
+       return 1;
+}
+
+static int yaffs2_wr_checkpt_data(struct yaffs_dev *dev)
+{
+       int ok = 1;
+
+       if (!yaffs2_checkpt_required(dev)) {
+               yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                       "skipping checkpoint write");
+               ok = 0;
+       }
+
+       if (ok)
+               ok = yaffs2_checkpt_open(dev, 1);
+
+       if (ok) {
+               yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                       "write checkpoint validity");
+               ok = yaffs2_wr_checkpt_validity_marker(dev, 1);
+       }
+       if (ok) {
+               yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                       "write checkpoint device");
+               ok = yaffs2_wr_checkpt_dev(dev);
+       }
+       if (ok) {
+               yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                       "write checkpoint objects");
+               ok = yaffs2_wr_checkpt_objs(dev);
+       }
+       if (ok) {
+               yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                       "write checkpoint validity");
+               ok = yaffs2_wr_checkpt_validity_marker(dev, 0);
+       }
+
+       if (ok)
+               ok = yaffs2_wr_checkpt_sum(dev);
+
+       if (!yaffs_checkpt_close(dev))
+               ok = 0;
+
+       if (ok)
+               dev->is_checkpointed = 1;
+       else
+               dev->is_checkpointed = 0;
+
+       return dev->is_checkpointed;
+}
+
+static int yaffs2_rd_checkpt_data(struct yaffs_dev *dev)
+{
+       int ok = 1;
+
+       if (!dev->param.is_yaffs2)
+               ok = 0;
+
+       if (ok && dev->param.skip_checkpt_rd) {
+               yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                       "skipping checkpoint read");
+               ok = 0;
+       }
+
+       if (ok)
+               ok = yaffs2_checkpt_open(dev, 0); /* open for read */
+
+       if (ok) {
+               yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                       "read checkpoint validity");
+               ok = yaffs2_rd_checkpt_validity_marker(dev, 1);
+       }
+       if (ok) {
+               yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                       "read checkpoint device");
+               ok = yaffs2_rd_checkpt_dev(dev);
+       }
+       if (ok) {
+               yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                       "read checkpoint objects");
+               ok = yaffs2_rd_checkpt_objs(dev);
+       }
+       if (ok) {
+               yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                       "read checkpoint validity");
+               ok = yaffs2_rd_checkpt_validity_marker(dev, 0);
+       }
+
+       if (ok) {
+               ok = yaffs2_rd_checkpt_sum(dev);
+               yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                       "read checkpoint checksum %d", ok);
+       }
+
+       if (!yaffs_checkpt_close(dev))
+               ok = 0;
+
+       if (ok)
+               dev->is_checkpointed = 1;
+       else
+               dev->is_checkpointed = 0;
+
+       return ok ? 1 : 0;
+
+}
+
+void yaffs2_checkpt_invalidate(struct yaffs_dev *dev)
+{
+       if (dev->is_checkpointed || dev->blocks_in_checkpt > 0) {
+               dev->is_checkpointed = 0;
+               yaffs2_checkpt_invalidate_stream(dev);
+       }
+       if (dev->param.sb_dirty_fn)
+               dev->param.sb_dirty_fn(dev);
+}
+
+int yaffs_checkpoint_save(struct yaffs_dev *dev)
+{
+
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+               "save entry: is_checkpointed %d",
+               dev->is_checkpointed);
+
+       yaffs_verify_objects(dev);
+       yaffs_verify_blocks(dev);
+       yaffs_verify_free_chunks(dev);
+
+       if (!dev->is_checkpointed) {
+               yaffs2_checkpt_invalidate(dev);
+               yaffs2_wr_checkpt_data(dev);
+       }
+
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT | YAFFS_TRACE_MOUNT,
+               "save exit: is_checkpointed %d",
+               dev->is_checkpointed);
+
+       return dev->is_checkpointed;
+}
+
+int yaffs2_checkpt_restore(struct yaffs_dev *dev)
+{
+       int retval;
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+               "restore entry: is_checkpointed %d",
+               dev->is_checkpointed);
+
+       retval = yaffs2_rd_checkpt_data(dev);
+
+       if (dev->is_checkpointed) {
+               yaffs_verify_objects(dev);
+               yaffs_verify_blocks(dev);
+               yaffs_verify_free_chunks(dev);
+       }
+
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+               "restore exit: is_checkpointed %d",
+               dev->is_checkpointed);
+
+       return retval;
+}
+
+int yaffs2_handle_hole(struct yaffs_obj *obj, loff_t new_size)
+{
+       /* if new_size > old_file_size.
+        * We're going to be writing a hole.
+        * If the hole is small then write zeros otherwise write a start of hole marker.
+        */
+
+       loff_t old_file_size;
+       int increase;
+       int small_hole;
+       int result = YAFFS_OK;
+       struct yaffs_dev *dev = NULL;
+
+       u8 *local_buffer = NULL;
+
+       int small_increase_ok = 0;
+
+       if (!obj)
+               return YAFFS_FAIL;
+
+       if (obj->variant_type != YAFFS_OBJECT_TYPE_FILE)
+               return YAFFS_FAIL;
+
+       dev = obj->my_dev;
+
+       /* Bail out if not yaffs2 mode */
+       if (!dev->param.is_yaffs2)
+               return YAFFS_OK;
+
+       old_file_size = obj->variant.file_variant.file_size;
+
+       if (new_size <= old_file_size)
+               return YAFFS_OK;
+
+       increase = new_size - old_file_size;
+
+       if (increase < YAFFS_SMALL_HOLE_THRESHOLD * dev->data_bytes_per_chunk &&
+           yaffs_check_alloc_available(dev, YAFFS_SMALL_HOLE_THRESHOLD + 1))
+               small_hole = 1;
+       else
+               small_hole = 0;
+
+       if (small_hole)
+               local_buffer = yaffs_get_temp_buffer(dev, __LINE__);
+
+       if (local_buffer) {
+               /* fill hole with zero bytes */
+               int pos = old_file_size;
+               int this_write;
+               int written;
+               memset(local_buffer, 0, dev->data_bytes_per_chunk);
+               small_increase_ok = 1;
+
+               while (increase > 0 && small_increase_ok) {
+                       this_write = increase;
+                       if (this_write > dev->data_bytes_per_chunk)
+                               this_write = dev->data_bytes_per_chunk;
+                       written =
+                           yaffs_do_file_wr(obj, local_buffer, pos, this_write,
+                                            0);
+                       if (written == this_write) {
+                               pos += this_write;
+                               increase -= this_write;
+                       } else {
+                               small_increase_ok = 0;
+                        }
+               }
+
+               yaffs_release_temp_buffer(dev, local_buffer, __LINE__);
+
+               /* If we were out of space then reverse any chunks we've added */
+               if (!small_increase_ok)
+                       yaffs_resize_file_down(obj, old_file_size);
+       }
+
+       if (!small_increase_ok &&
+           obj->parent &&
+           obj->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
+           obj->parent->obj_id != YAFFS_OBJECTID_DELETED) {
+               /* Write a hole start header with the old file size */
+               yaffs_update_oh(obj, NULL, 0, 1, 0, NULL);
+       }
+
+       return result;
+
+}
+
+struct yaffs_block_index {
+       int seq;
+       int block;
+};
+
+static int yaffs2_ybicmp(const void *a, const void *b)
+{
+       int aseq = ((struct yaffs_block_index *)a)->seq;
+       int bseq = ((struct yaffs_block_index *)b)->seq;
+       int ablock = ((struct yaffs_block_index *)a)->block;
+       int bblock = ((struct yaffs_block_index *)b)->block;
+       if (aseq == bseq)
+               return ablock - bblock;
+       else
+               return aseq - bseq;
+}
+
+int yaffs2_scan_backwards(struct yaffs_dev *dev)
+{
+       struct yaffs_ext_tags tags;
+       int blk;
+       int block_iter;
+       int start_iter;
+       int end_iter;
+       int n_to_scan = 0;
+
+       int chunk;
+       int result;
+       int c;
+       int deleted;
+       enum yaffs_block_state state;
+       struct yaffs_obj *hard_list = NULL;
+       struct yaffs_block_info *bi;
+       u32 seq_number;
+       struct yaffs_obj_hdr *oh;
+       struct yaffs_obj *in;
+       struct yaffs_obj *parent;
+       int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
+       int is_unlinked;
+       u8 *chunk_data;
+
+       int file_size;
+       int is_shrink;
+       int found_chunks;
+       int equiv_id;
+       int alloc_failed = 0;
+
+       struct yaffs_block_index *block_index = NULL;
+       int alt_block_index = 0;
+
+       yaffs_trace(YAFFS_TRACE_SCAN,
+               "yaffs2_scan_backwards starts  intstartblk %d intendblk %d...",
+               dev->internal_start_block, dev->internal_end_block);
+
+       dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
+
+       block_index = kmalloc(n_blocks * sizeof(struct yaffs_block_index),
+                       GFP_NOFS);
+
+       if (!block_index) {
+               block_index =
+                   vmalloc(n_blocks * sizeof(struct yaffs_block_index));
+               alt_block_index = 1;
+       }
+
+       if (!block_index) {
+               yaffs_trace(YAFFS_TRACE_SCAN,
+                       "yaffs2_scan_backwards() could not allocate block index!"
+                       );
+               return YAFFS_FAIL;
+       }
+
+       dev->blocks_in_checkpt = 0;
+
+       chunk_data = yaffs_get_temp_buffer(dev, __LINE__);
+
+       /* Scan all the blocks to determine their state */
+       bi = dev->block_info;
+       for (blk = dev->internal_start_block; blk <= dev->internal_end_block;
+            blk++) {
+               yaffs_clear_chunk_bits(dev, blk);
+               bi->pages_in_use = 0;
+               bi->soft_del_pages = 0;
+
+               yaffs_query_init_block_state(dev, blk, &state, &seq_number);
+
+               bi->block_state = state;
+               bi->seq_number = seq_number;
+
+               if (bi->seq_number == YAFFS_SEQUENCE_CHECKPOINT_DATA)
+                       bi->block_state = state = YAFFS_BLOCK_STATE_CHECKPOINT;
+               if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
+                       bi->block_state = state = YAFFS_BLOCK_STATE_DEAD;
+
+               yaffs_trace(YAFFS_TRACE_SCAN_DEBUG,
+                       "Block scanning block %d state %d seq %d",
+                       blk, state, seq_number);
+
+               if (state == YAFFS_BLOCK_STATE_CHECKPOINT) {
+                       dev->blocks_in_checkpt++;
+
+               } else if (state == YAFFS_BLOCK_STATE_DEAD) {
+                       yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
+                               "block %d is bad", blk);
+               } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
+                       yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "Block empty ");
+                       dev->n_erased_blocks++;
+                       dev->n_free_chunks += dev->param.chunks_per_block;
+               } else if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
+
+                       /* Determine the highest sequence number */
+                       if (seq_number >= YAFFS_LOWEST_SEQUENCE_NUMBER &&
+                           seq_number < YAFFS_HIGHEST_SEQUENCE_NUMBER) {
+
+                               block_index[n_to_scan].seq = seq_number;
+                               block_index[n_to_scan].block = blk;
+
+                               n_to_scan++;
+
+                               if (seq_number >= dev->seq_number)
+                                       dev->seq_number = seq_number;
+                       } else {
+                               /* TODO: Nasty sequence number! */
+                               yaffs_trace(YAFFS_TRACE_SCAN,
+                                       "Block scanning block %d has bad sequence number %d",
+                                       blk, seq_number);
+
+                       }
+               }
+               bi++;
+       }
+
+       yaffs_trace(YAFFS_TRACE_SCAN, "%d blocks to be sorted...", n_to_scan);
+
+       cond_resched();
+
+       /* Sort the blocks by sequence number */
+       sort(block_index, n_to_scan, sizeof(struct yaffs_block_index),
+                  yaffs2_ybicmp, NULL);
+
+       cond_resched();
+
+       yaffs_trace(YAFFS_TRACE_SCAN, "...done");
+
+       /* Now scan the blocks looking at the data. */
+       start_iter = 0;
+       end_iter = n_to_scan - 1;
+       yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "%d blocks to scan", n_to_scan);
+
+       /* For each block.... backwards */
+       for (block_iter = end_iter; !alloc_failed && block_iter >= start_iter;
+            block_iter--) {
+               /* Cooperative multitasking! This loop can run for so
+                  long that watchdog timers expire. */
+               cond_resched();
+
+               /* get the block to scan in the correct order */
+               blk = block_index[block_iter].block;
+
+               bi = yaffs_get_block_info(dev, blk);
+
+               state = bi->block_state;
+
+               deleted = 0;
+
+               /* For each chunk in each block that needs scanning.... */
+               found_chunks = 0;
+               for (c = dev->param.chunks_per_block - 1;
+                    !alloc_failed && c >= 0 &&
+                    (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
+                     state == YAFFS_BLOCK_STATE_ALLOCATING); c--) {
+                       /* Scan backwards...
+                        * Read the tags and decide what to do
+                        */
+
+                       chunk = blk * dev->param.chunks_per_block + c;
+
+                       result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL,
+                                                         &tags);
+
+                       /* Let's have a good look at this chunk... */
+
+                       if (!tags.chunk_used) {
+                               /* An unassigned chunk in the block.
+                                * If there are used chunks after this one, then
+                                * it is a chunk that was skipped due to failing the erased
+                                * check. Just skip it so that it can be deleted.
+                                * But, more typically, We get here when this is an unallocated
+                                * chunk and his means that either the block is empty or
+                                * this is the one being allocated from
+                                */
+
+                               if (found_chunks) {
+                                       /* This is a chunk that was skipped due to failing the erased check */
+                               } else if (c == 0) {
+                                       /* We're looking at the first chunk in the block so the block is unused */
+                                       state = YAFFS_BLOCK_STATE_EMPTY;
+                                       dev->n_erased_blocks++;
+                               } else {
+                                       if (state ==
+                                           YAFFS_BLOCK_STATE_NEEDS_SCANNING
+                                           || state ==
+                                           YAFFS_BLOCK_STATE_ALLOCATING) {
+                                               if (dev->seq_number ==
+                                                   bi->seq_number) {
+                                                       /* this is the block being allocated from */
+
+                                                       yaffs_trace(YAFFS_TRACE_SCAN,
+                                                               " Allocating from %d %d",
+                                                               blk, c);
+
+                                                       state =
+                                                           YAFFS_BLOCK_STATE_ALLOCATING;
+                                                       dev->alloc_block = blk;
+                                                       dev->alloc_page = c;
+                                                       dev->
+                                                           alloc_block_finder =
+                                                           blk;
+                                               } else {
+                                                       /* This is a partially written block that is not
+                                                        * the current allocation block.
+                                                        */
+
+                                                       yaffs_trace(YAFFS_TRACE_SCAN,
+                                                               "Partially written block %d detected",
+                                                               blk);
+                                               }
+                                       }
+                               }
+
+                               dev->n_free_chunks++;
+
+                       } else if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED) {
+                               yaffs_trace(YAFFS_TRACE_SCAN,
+                                       " Unfixed ECC in chunk(%d:%d), chunk ignored",
+                                       blk, c);
+
+                               dev->n_free_chunks++;
+
+                       } else if (tags.obj_id > YAFFS_MAX_OBJECT_ID ||
+                                  tags.chunk_id > YAFFS_MAX_CHUNK_ID ||
+                                  (tags.chunk_id > 0
+                                   && tags.n_bytes > dev->data_bytes_per_chunk)
+                                  || tags.seq_number != bi->seq_number) {
+                               yaffs_trace(YAFFS_TRACE_SCAN,
+                                       "Chunk (%d:%d) with bad tags:obj = %d, chunk_id = %d, n_bytes = %d, ignored",
+                                       blk, c, tags.obj_id,
+                                       tags.chunk_id, tags.n_bytes);
+
+                               dev->n_free_chunks++;
+
+                       } else if (tags.chunk_id > 0) {
+                               /* chunk_id > 0 so it is a data chunk... */
+                               unsigned int endpos;
+                               u32 chunk_base =
+                                   (tags.chunk_id -
+                                    1) * dev->data_bytes_per_chunk;
+
+                               found_chunks = 1;
+
+                               yaffs_set_chunk_bit(dev, blk, c);
+                               bi->pages_in_use++;
+
+                               in = yaffs_find_or_create_by_number(dev,
+                                                                   tags.obj_id,
+                                                                   YAFFS_OBJECT_TYPE_FILE);
+                               if (!in) {
+                                       /* Out of memory */
+                                       alloc_failed = 1;
+                               }
+
+                               if (in &&
+                                   in->variant_type == YAFFS_OBJECT_TYPE_FILE
+                                   && chunk_base <
+                                   in->variant.file_variant.shrink_size) {
+                                       /* This has not been invalidated by a resize */
+                                       if (!yaffs_put_chunk_in_file
+                                           (in, tags.chunk_id, chunk, -1)) {
+                                               alloc_failed = 1;
+                                       }
+
+                                       /* File size is calculated by looking at the data chunks if we have not
+                                        * seen an object header yet. Stop this practice once we find an object header.
+                                        */
+                                       endpos = chunk_base + tags.n_bytes;
+
+                                       if (!in->valid &&       /* have not got an object header yet */
+                                           in->variant.file_variant.
+                                           scanned_size < endpos) {
+                                               in->variant.file_variant.
+                                                   scanned_size = endpos;
+                                               in->variant.file_variant.
+                                                   file_size = endpos;
+                                       }
+
+                               } else if (in) {
+                                       /* This chunk has been invalidated by a resize, or a past file deletion
+                                        * so delete the chunk*/
+                                       yaffs_chunk_del(dev, chunk, 1,
+                                                       __LINE__);
+
+                               }
+                       } else {
+                               /* chunk_id == 0, so it is an ObjectHeader.
+                                * Thus, we read in the object header and make the object
+                                */
+                               found_chunks = 1;
+
+                               yaffs_set_chunk_bit(dev, blk, c);
+                               bi->pages_in_use++;
+
+                               oh = NULL;
+                               in = NULL;
+
+                               if (tags.extra_available) {
+                                       in = yaffs_find_or_create_by_number(dev,
+                                                                           tags.
+                                                                           obj_id,
+                                                                           tags.
+                                                                           extra_obj_type);
+                                       if (!in)
+                                               alloc_failed = 1;
+                               }
+
+                               if (!in ||
+                                   (!in->valid && dev->param.disable_lazy_load)
+                                   || tags.extra_shadows || (!in->valid
+                                                             && (tags.obj_id ==
+                                                                 YAFFS_OBJECTID_ROOT
+                                                                 || tags.
+                                                                 obj_id ==
+                                                                 YAFFS_OBJECTID_LOSTNFOUND)))
+                               {
+
+                                       /* If we don't have  valid info then we need to read the chunk
+                                        * TODO In future we can probably defer reading the chunk and
+                                        * living with invalid data until needed.
+                                        */
+
+                                       result = yaffs_rd_chunk_tags_nand(dev,
+                                                                         chunk,
+                                                                         chunk_data,
+                                                                         NULL);
+
+                                       oh = (struct yaffs_obj_hdr *)chunk_data;
+
+                                       if (dev->param.inband_tags) {
+                                               /* Fix up the header if they got corrupted by inband tags */
+                                               oh->shadows_obj =
+                                                   oh->inband_shadowed_obj_id;
+                                               oh->is_shrink =
+                                                   oh->inband_is_shrink;
+                                       }
+
+                                       if (!in) {
+                                               in = yaffs_find_or_create_by_number(dev, tags.obj_id, oh->type);
+                                               if (!in)
+                                                       alloc_failed = 1;
+                                       }
+
+                               }
+
+                               if (!in) {
+                                       /* TODO Hoosterman we have a problem! */
+                                       yaffs_trace(YAFFS_TRACE_ERROR,
+                                               "yaffs tragedy: Could not make object for object  %d at chunk %d during scan",
+                                               tags.obj_id, chunk);
+                                       continue;
+                               }
+
+                               if (in->valid) {
+                                       /* We have already filled this one.
+                                        * We have a duplicate that will be discarded, but
+                                        * we first have to suck out resize info if it is a file.
+                                        */
+
+                                       if ((in->variant_type ==
+                                            YAFFS_OBJECT_TYPE_FILE) && ((oh
+                                                                         &&
+                                                                         oh->
+                                                                         type
+                                                                         ==
+                                                                         YAFFS_OBJECT_TYPE_FILE)
+                                                                        ||
+                                                                        (tags.
+                                                                         extra_available
+                                                                         &&
+                                                                         tags.
+                                                                         extra_obj_type
+                                                                         ==
+                                                                         YAFFS_OBJECT_TYPE_FILE)))
+                                       {
+                                               u32 this_size =
+                                                   (oh) ? oh->
+                                                   file_size :
+                                                   tags.extra_length;
+                                               u32 parent_obj_id =
+                                                   (oh) ? oh->parent_obj_id :
+                                                   tags.extra_parent_id;
+
+                                               is_shrink =
+                                                   (oh) ? oh->
+                                                   is_shrink :
+                                                   tags.extra_is_shrink;
+
+                                               /* If it is deleted (unlinked at start also means deleted)
+                                                * we treat the file size as being zeroed at this point.
+                                                */
+                                               if (parent_obj_id ==
+                                                   YAFFS_OBJECTID_DELETED
+                                                   || parent_obj_id ==
+                                                   YAFFS_OBJECTID_UNLINKED) {
+                                                       this_size = 0;
+                                                       is_shrink = 1;
+                                               }
+
+                                               if (is_shrink
+                                                   && in->variant.file_variant.
+                                                   shrink_size > this_size)
+                                                       in->variant.
+                                                           file_variant.
+                                                           shrink_size =
+                                                           this_size;
+
+                                               if (is_shrink)
+                                                       bi->has_shrink_hdr = 1;
+
+                                       }
+                                       /* Use existing - destroy this one. */
+                                       yaffs_chunk_del(dev, chunk, 1,
+                                                       __LINE__);
+
+                               }
+
+                               if (!in->valid && in->variant_type !=
+                                   (oh ? oh->type : tags.extra_obj_type))
+                                       yaffs_trace(YAFFS_TRACE_ERROR,
+                                               "yaffs tragedy: Bad object type, %d != %d, for object %d at chunk %d during scan",
+                                               oh ?
+                                               oh->type : tags.extra_obj_type,
+                                               in->variant_type, tags.obj_id,
+                                               chunk);
+
+                               if (!in->valid &&
+                                   (tags.obj_id == YAFFS_OBJECTID_ROOT ||
+                                    tags.obj_id ==
+                                    YAFFS_OBJECTID_LOSTNFOUND)) {
+                                       /* We only load some info, don't fiddle with directory structure */
+                                       in->valid = 1;
+
+                                       if (oh) {
+
+                                               in->yst_mode = oh->yst_mode;
+                                               yaffs_load_attribs(in, oh);
+                                               in->lazy_loaded = 0;
+                                       } else {
+                                               in->lazy_loaded = 1;
+                                        }
+                                       in->hdr_chunk = chunk;
+
+                               } else if (!in->valid) {
+                                       /* we need to load this info */
+
+                                       in->valid = 1;
+                                       in->hdr_chunk = chunk;
+
+                                       if (oh) {
+                                               in->variant_type = oh->type;
+
+                                               in->yst_mode = oh->yst_mode;
+                                               yaffs_load_attribs(in, oh);
+
+                                               if (oh->shadows_obj > 0)
+                                                       yaffs_handle_shadowed_obj
+                                                           (dev,
+                                                            oh->shadows_obj,
+                                                            1);
+
+                                               yaffs_set_obj_name_from_oh(in,
+                                                                          oh);
+                                               parent =
+                                                   yaffs_find_or_create_by_number
+                                                   (dev, oh->parent_obj_id,
+                                                    YAFFS_OBJECT_TYPE_DIRECTORY);
+
+                                               file_size = oh->file_size;
+                                               is_shrink = oh->is_shrink;
+                                               equiv_id = oh->equiv_id;
+
+                                       } else {
+                                               in->variant_type =
+                                                   tags.extra_obj_type;
+                                               parent =
+                                                   yaffs_find_or_create_by_number
+                                                   (dev, tags.extra_parent_id,
+                                                    YAFFS_OBJECT_TYPE_DIRECTORY);
+                                               file_size = tags.extra_length;
+                                               is_shrink =
+                                                   tags.extra_is_shrink;
+                                               equiv_id = tags.extra_equiv_id;
+                                               in->lazy_loaded = 1;
+
+                                       }
+                                       in->dirty = 0;
+
+                                       if (!parent)
+                                               alloc_failed = 1;
+
+                                       /* directory stuff...
+                                        * hook up to parent
+                                        */
+
+                                       if (parent && parent->variant_type ==
+                                           YAFFS_OBJECT_TYPE_UNKNOWN) {
+                                               /* Set up as a directory */
+                                               parent->variant_type =
+                                                   YAFFS_OBJECT_TYPE_DIRECTORY;
+                                               INIT_LIST_HEAD(&parent->
+                                                              variant.dir_variant.children);
+                                       } else if (!parent
+                                                  || parent->variant_type !=
+                                                  YAFFS_OBJECT_TYPE_DIRECTORY) {
+                                               /* Hoosterman, another problem....
+                                                * We're trying to use a non-directory as a directory
+                                                */
+
+                                               yaffs_trace(YAFFS_TRACE_ERROR,
+                                                       "yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
+                                                       );
+                                               parent = dev->lost_n_found;
+                                       }
+
+                                       yaffs_add_obj_to_dir(parent, in);
+
+                                       is_unlinked = (parent == dev->del_dir)
+                                           || (parent == dev->unlinked_dir);
+
+                                       if (is_shrink) {
+                                               /* Mark the block as having a shrink header */
+                                               bi->has_shrink_hdr = 1;
+                                       }
+
+                                       /* Note re hardlinks.
+                                        * Since we might scan a hardlink before its equivalent object is scanned
+                                        * we put them all in a list.
+                                        * After scanning is complete, we should have all the objects, so we run
+                                        * through this list and fix up all the chains.
+                                        */
+
+                                       switch (in->variant_type) {
+                                       case YAFFS_OBJECT_TYPE_UNKNOWN:
+                                               /* Todo got a problem */
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_FILE:
+
+                                               if (in->variant.
+                                                   file_variant.scanned_size <
+                                                   file_size) {
+                                                       /* This covers the case where the file size is greater
+                                                        * than where the data is
+                                                        * This will happen if the file is resized to be larger
+                                                        * than its current data extents.
+                                                        */
+                                                       in->variant.
+                                                           file_variant.
+                                                           file_size =
+                                                           file_size;
+                                                       in->variant.
+                                                           file_variant.
+                                                           scanned_size =
+                                                           file_size;
+                                               }
+
+                                               if (in->variant.file_variant.
+                                                   shrink_size > file_size)
+                                                       in->variant.
+                                                           file_variant.
+                                                           shrink_size =
+                                                           file_size;
+
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_HARDLINK:
+                                               if (!is_unlinked) {
+                                                       in->variant.
+                                                           hardlink_variant.
+                                                           equiv_id = equiv_id;
+                                                       in->hard_links.next =
+                                                           (struct list_head *)
+                                                           hard_list;
+                                                       hard_list = in;
+                                               }
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_DIRECTORY:
+                                               /* Do nothing */
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_SPECIAL:
+                                               /* Do nothing */
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_SYMLINK:
+                                               if (oh) {
+                                                       in->variant.
+                                                           symlink_variant.
+                                                           alias =
+                                                           yaffs_clone_str(oh->
+                                                                           alias);
+                                                       if (!in->variant.
+                                                           symlink_variant.
+                                                           alias)
+                                                               alloc_failed =
+                                                                   1;
+                                               }
+                                               break;
+                                       }
+
+                               }
+
+                       }
+
+               }               /* End of scanning for each chunk */
+
+               if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
+                       /* If we got this far while scanning, then the block is fully allocated. */
+                       state = YAFFS_BLOCK_STATE_FULL;
+               }
+
+               bi->block_state = state;
+
+               /* Now let's see if it was dirty */
+               if (bi->pages_in_use == 0 &&
+                   !bi->has_shrink_hdr &&
+                   bi->block_state == YAFFS_BLOCK_STATE_FULL) {
+                       yaffs_block_became_dirty(dev, blk);
+               }
+
+       }
+
+       yaffs_skip_rest_of_block(dev);
+
+       if (alt_block_index)
+               vfree(block_index);
+       else
+               kfree(block_index);
+
+       /* Ok, we've done all the scanning.
+        * Fix up the hard link chains.
+        * We should now have scanned all the objects, now it's time to add these
+        * hardlinks.
+        */
+       yaffs_link_fixup(dev, hard_list);
+
+       yaffs_release_temp_buffer(dev, chunk_data, __LINE__);
+
+       if (alloc_failed)
+               return YAFFS_FAIL;
+
+       yaffs_trace(YAFFS_TRACE_SCAN, "yaffs2_scan_backwards ends");
+
+       return YAFFS_OK;
+}
diff --git a/fs/yaffs2/yaffs_yaffs2.h b/fs/yaffs2/yaffs_yaffs2.h
new file mode 100644 (file)
index 0000000..e1a9287
--- /dev/null
@@ -0,0 +1,39 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_YAFFS2_H__
+#define __YAFFS_YAFFS2_H__
+
+#include "yaffs_guts.h"
+
+void yaffs_calc_oldest_dirty_seq(struct yaffs_dev *dev);
+void yaffs2_find_oldest_dirty_seq(struct yaffs_dev *dev);
+void yaffs2_clear_oldest_dirty_seq(struct yaffs_dev *dev,
+                                  struct yaffs_block_info *bi);
+void yaffs2_update_oldest_dirty_seq(struct yaffs_dev *dev, unsigned block_no,
+                                   struct yaffs_block_info *bi);
+int yaffs_block_ok_for_gc(struct yaffs_dev *dev, struct yaffs_block_info *bi);
+u32 yaffs2_find_refresh_block(struct yaffs_dev *dev);
+int yaffs2_checkpt_required(struct yaffs_dev *dev);
+int yaffs_calc_checkpt_blocks_required(struct yaffs_dev *dev);
+
+void yaffs2_checkpt_invalidate(struct yaffs_dev *dev);
+int yaffs2_checkpt_save(struct yaffs_dev *dev);
+int yaffs2_checkpt_restore(struct yaffs_dev *dev);
+
+int yaffs2_handle_hole(struct yaffs_obj *obj, loff_t new_size);
+int yaffs2_scan_backwards(struct yaffs_dev *dev);
+
+#endif
diff --git a/fs/yaffs2/yportenv.h b/fs/yaffs2/yportenv.h
new file mode 100644 (file)
index 0000000..236f579
--- /dev/null
@@ -0,0 +1,70 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YPORTENV_LINUX_H__
+#define __YPORTENV_LINUX_H__
+
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/xattr.h>
+#include <linux/list.h>
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/stat.h>
+#include <linux/sort.h>
+#include <linux/bitops.h>
+
+#define YCHAR char
+#define YUCHAR unsigned char
+#define _Y(x)     x
+
+#define YAFFS_LOSTNFOUND_NAME          "lost+found"
+#define YAFFS_LOSTNFOUND_PREFIX                "obj"
+
+
+#define YAFFS_ROOT_MODE                        0755
+#define YAFFS_LOSTNFOUND_MODE          0700
+
+#define Y_CURRENT_TIME CURRENT_TIME.tv_sec
+#define Y_TIME_CONVERT(x) (x).tv_sec
+
+#define compile_time_assertion(assertion) \
+       ({ int x = __builtin_choose_expr(assertion, 0, (void)0); (void) x; })
+
+
+#ifndef Y_DUMP_STACK
+#define Y_DUMP_STACK() dump_stack()
+#endif
+
+#define yaffs_trace(msk, fmt, ...) do { \
+       if(yaffs_trace_mask & ((msk) | YAFFS_TRACE_ALWAYS)) \
+               printk(KERN_DEBUG "yaffs: " fmt "\n", ##__VA_ARGS__); \
+} while(0)
+
+#ifndef YBUG
+#define YBUG() do {\
+       yaffs_trace(YAFFS_TRACE_BUG,\
+               "bug " __FILE__ " %d",\
+               __LINE__);\
+       Y_DUMP_STACK();\
+} while (0)
+#endif
+
+#endif