From: Chris Mason <chris.mason@oracle.com>
Date: Wed, 11 Apr 2007 17:57:44 +0000 (-0400)
Subject: Btrfs: early support for multiple devices
X-Git-Tag: firefly_0821_release~15789^2~11^2~55^2~56^2~30^2~601
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0bd93ba022f5c1ddb4e5b722b02f3c4a4a8865ad;p=firefly-linux-kernel-4.4.55.git
Btrfs: early support for multiple devices
Signed-off-by: Chris Mason <chris.mason@oracle.com>
---
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 3f3a23f52a3b..01310de2bf4a 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -13,10 +13,11 @@ extern struct kmem_cache *btrfs_path_cachep;
#define BTRFS_MAGIC "_BtRfS_M"
#define BTRFS_ROOT_TREE_OBJECTID 1ULL
-#define BTRFS_EXTENT_TREE_OBJECTID 2ULL
-#define BTRFS_FS_TREE_OBJECTID 3ULL
-#define BTRFS_ROOT_TREE_DIR_OBJECTID 4ULL
-#define BTRFS_FIRST_FREE_OBJECTID 5ULL
+#define BTRFS_DEV_TREE_OBJECTID 2ULL
+#define BTRFS_EXTENT_TREE_OBJECTID 3ULL
+#define BTRFS_FS_TREE_OBJECTID 4ULL
+#define BTRFS_ROOT_TREE_DIR_OBJECTID 5ULL
+#define BTRFS_FIRST_FREE_OBJECTID 6ULL
/*
* we can actually store much bigger names, but lets not confuse the rest
@@ -90,6 +91,10 @@ struct btrfs_super_block {
__le64 total_blocks;
__le64 blocks_used;
__le64 root_dir_objectid;
+ /* fields below here vary with the underlying disk */
+ __le64 device_block_start;
+ __le64 device_num_blocks;
+ __le64 device_root;
} __attribute__ ((__packed__));
/*
@@ -223,10 +228,15 @@ struct btrfs_csum_item {
u8 csum[BTRFS_CSUM_SIZE];
} __attribute__ ((__packed__));
+struct btrfs_device_item {
+ __le16 pathlen;
+} __attribute__ ((__packed__));
+
struct crypto_hash;
struct btrfs_fs_info {
struct btrfs_root *extent_root;
struct btrfs_root *tree_root;
+ struct btrfs_root *dev_root;
struct btrfs_key current_insert;
struct btrfs_key last_insert;
struct radix_tree_root fs_roots_radix;
@@ -312,11 +322,16 @@ struct btrfs_root {
*/
#define BTRFS_EXTENT_ITEM_KEY 8
+/*
+ * dev items list the devices that make up the FS
+ */
+#define BTRFS_DEV_ITEM_KEY 9
+
/*
* string items are for debugging. They just store a short string of
* data in the FS
*/
-#define BTRFS_STRING_ITEM_KEY 9
+#define BTRFS_STRING_ITEM_KEY 10
static inline u64 btrfs_inode_generation(struct btrfs_inode_item *i)
{
@@ -782,6 +797,40 @@ static inline void btrfs_set_super_root_dir(struct btrfs_super_block *s, u64
s->root_dir_objectid = cpu_to_le64(val);
}
+static inline u64 btrfs_super_device_block_start(struct btrfs_super_block *s)
+{
+ return le64_to_cpu(s->device_block_start);
+}
+
+static inline void btrfs_set_super_device_block_start(struct btrfs_super_block
+ *s, u64 val)
+{
+ s->device_block_start = cpu_to_le64(val);
+}
+
+static inline u64 btrfs_super_device_num_blocks(struct btrfs_super_block *s)
+{
+ return le64_to_cpu(s->device_num_blocks);
+}
+
+static inline void btrfs_set_super_device_num_blocks(struct btrfs_super_block
+ *s, u64 val)
+{
+ s->device_num_blocks = cpu_to_le64(val);
+}
+
+static inline u64 btrfs_super_device_root(struct btrfs_super_block *s)
+{
+ return le64_to_cpu(s->device_root);
+}
+
+static inline void btrfs_set_super_device_root(struct btrfs_super_block
+ *s, u64 val)
+{
+ s->device_root = cpu_to_le64(val);
+}
+
+
static inline u8 *btrfs_leaf_data(struct btrfs_leaf *l)
{
return (u8 *)l->items;
@@ -849,6 +898,17 @@ static inline void btrfs_set_file_extent_num_blocks(struct
e->num_blocks = cpu_to_le64(val);
}
+static inline u16 btrfs_device_pathlen(struct btrfs_device_item *d)
+{
+ return le16_to_cpu(d->pathlen);
+}
+
+static inline void btrfs_set_device_pathlen(struct btrfs_device_item *d,
+ u16 val)
+{
+ d->pathlen = cpu_to_le16(val);
+}
+
static inline struct btrfs_root *btrfs_sb(struct super_block *sb)
{
return sb->s_fs_info;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index ff69162829b3..e09233262af6 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -378,6 +378,8 @@ struct btrfs_root *open_ctree(struct super_block *sb)
{
struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
GFP_NOFS);
+ struct btrfs_root *dev_root = kmalloc(sizeof(struct btrfs_root),
+ GFP_NOFS);
struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
GFP_NOFS);
struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
@@ -392,6 +394,7 @@ struct btrfs_root *open_ctree(struct super_block *sb)
fs_info->running_transaction = NULL;
fs_info->tree_root = tree_root;
fs_info->extent_root = extent_root;
+ fs_info->dev_root = dev_root;
fs_info->sb = sb;
fs_info->btree_inode = new_inode(sb);
fs_info->btree_inode->i_ino = 1;
@@ -414,6 +417,9 @@ struct btrfs_root *open_ctree(struct super_block *sb)
memset(&fs_info->current_insert, 0, sizeof(fs_info->current_insert));
memset(&fs_info->last_insert, 0, sizeof(fs_info->last_insert));
+ __setup_root(sb->s_blocksize, dev_root,
+ fs_info, BTRFS_DEV_TREE_OBJECTID);
+
__setup_root(sb->s_blocksize, tree_root,
fs_info, BTRFS_ROOT_TREE_OBJECTID);
fs_info->sb_buffer = read_tree_block(tree_root,
@@ -427,6 +433,8 @@ struct btrfs_root *open_ctree(struct super_block *sb)
return NULL;
fs_info->disk_super = disk_super;
+ dev_root->node = read_tree_block(tree_root,
+ btrfs_super_device_root(disk_super));
tree_root->node = read_tree_block(tree_root,
btrfs_super_root(disk_super));
BUG_ON(!tree_root->node);
@@ -519,6 +527,9 @@ int close_ctree(struct btrfs_root *root)
if (fs_info->extent_root->node)
btrfs_block_release(fs_info->extent_root,
fs_info->extent_root->node);
+ if (fs_info->dev_root->node)
+ btrfs_block_release(fs_info->dev_root,
+ fs_info->dev_root->node);
if (fs_info->tree_root->node)
btrfs_block_release(fs_info->tree_root,
fs_info->tree_root->node);