2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
24 #include <linux/fsnotify.h>
25 #include <linux/pagemap.h>
26 #include <linux/highmem.h>
27 #include <linux/time.h>
28 #include <linux/init.h>
29 #include <linux/string.h>
30 #include <linux/backing-dev.h>
31 #include <linux/mount.h>
32 #include <linux/mpage.h>
33 #include <linux/namei.h>
34 #include <linux/swap.h>
35 #include <linux/writeback.h>
36 #include <linux/statfs.h>
37 #include <linux/compat.h>
38 #include <linux/bit_spinlock.h>
39 #include <linux/security.h>
40 #include <linux/xattr.h>
41 #include <linux/vmalloc.h>
45 #include "transaction.h"
46 #include "btrfs_inode.h"
48 #include "print-tree.h"
52 /* Mask out flags that are inappropriate for the given type of inode. */
53 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
57 else if (S_ISREG(mode))
58 return flags & ~FS_DIRSYNC_FL;
60 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
64 * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
66 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
68 unsigned int iflags = 0;
70 if (flags & BTRFS_INODE_SYNC)
72 if (flags & BTRFS_INODE_IMMUTABLE)
73 iflags |= FS_IMMUTABLE_FL;
74 if (flags & BTRFS_INODE_APPEND)
75 iflags |= FS_APPEND_FL;
76 if (flags & BTRFS_INODE_NODUMP)
77 iflags |= FS_NODUMP_FL;
78 if (flags & BTRFS_INODE_NOATIME)
79 iflags |= FS_NOATIME_FL;
80 if (flags & BTRFS_INODE_DIRSYNC)
81 iflags |= FS_DIRSYNC_FL;
87 * Update inode->i_flags based on the btrfs internal flags.
89 void btrfs_update_iflags(struct inode *inode)
91 struct btrfs_inode *ip = BTRFS_I(inode);
93 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
95 if (ip->flags & BTRFS_INODE_SYNC)
96 inode->i_flags |= S_SYNC;
97 if (ip->flags & BTRFS_INODE_IMMUTABLE)
98 inode->i_flags |= S_IMMUTABLE;
99 if (ip->flags & BTRFS_INODE_APPEND)
100 inode->i_flags |= S_APPEND;
101 if (ip->flags & BTRFS_INODE_NOATIME)
102 inode->i_flags |= S_NOATIME;
103 if (ip->flags & BTRFS_INODE_DIRSYNC)
104 inode->i_flags |= S_DIRSYNC;
108 * Inherit flags from the parent inode.
110 * Unlike extN we don't have any flags we don't want to inherit currently.
112 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
119 flags = BTRFS_I(dir)->flags;
121 if (S_ISREG(inode->i_mode))
122 flags &= ~BTRFS_INODE_DIRSYNC;
123 else if (!S_ISDIR(inode->i_mode))
124 flags &= (BTRFS_INODE_NODUMP | BTRFS_INODE_NOATIME);
126 BTRFS_I(inode)->flags = flags;
127 btrfs_update_iflags(inode);
130 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
132 struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode);
133 unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
135 if (copy_to_user(arg, &flags, sizeof(flags)))
140 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
142 struct inode *inode = file->f_path.dentry->d_inode;
143 struct btrfs_inode *ip = BTRFS_I(inode);
144 struct btrfs_root *root = ip->root;
145 struct btrfs_trans_handle *trans;
146 unsigned int flags, oldflags;
149 if (copy_from_user(&flags, arg, sizeof(flags)))
152 if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
153 FS_NOATIME_FL | FS_NODUMP_FL | \
154 FS_SYNC_FL | FS_DIRSYNC_FL))
157 if (!is_owner_or_cap(inode))
160 mutex_lock(&inode->i_mutex);
162 flags = btrfs_mask_flags(inode->i_mode, flags);
163 oldflags = btrfs_flags_to_ioctl(ip->flags);
164 if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
165 if (!capable(CAP_LINUX_IMMUTABLE)) {
171 ret = mnt_want_write(file->f_path.mnt);
175 if (flags & FS_SYNC_FL)
176 ip->flags |= BTRFS_INODE_SYNC;
178 ip->flags &= ~BTRFS_INODE_SYNC;
179 if (flags & FS_IMMUTABLE_FL)
180 ip->flags |= BTRFS_INODE_IMMUTABLE;
182 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
183 if (flags & FS_APPEND_FL)
184 ip->flags |= BTRFS_INODE_APPEND;
186 ip->flags &= ~BTRFS_INODE_APPEND;
187 if (flags & FS_NODUMP_FL)
188 ip->flags |= BTRFS_INODE_NODUMP;
190 ip->flags &= ~BTRFS_INODE_NODUMP;
191 if (flags & FS_NOATIME_FL)
192 ip->flags |= BTRFS_INODE_NOATIME;
194 ip->flags &= ~BTRFS_INODE_NOATIME;
195 if (flags & FS_DIRSYNC_FL)
196 ip->flags |= BTRFS_INODE_DIRSYNC;
198 ip->flags &= ~BTRFS_INODE_DIRSYNC;
201 trans = btrfs_join_transaction(root, 1);
204 ret = btrfs_update_inode(trans, root, inode);
207 btrfs_update_iflags(inode);
208 inode->i_ctime = CURRENT_TIME;
209 btrfs_end_transaction(trans, root);
211 mnt_drop_write(file->f_path.mnt);
213 mutex_unlock(&inode->i_mutex);
217 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
219 struct inode *inode = file->f_path.dentry->d_inode;
221 return put_user(inode->i_generation, arg);
224 static noinline int create_subvol(struct btrfs_root *root,
225 struct dentry *dentry,
226 char *name, int namelen)
228 struct btrfs_trans_handle *trans;
229 struct btrfs_key key;
230 struct btrfs_root_item root_item;
231 struct btrfs_inode_item *inode_item;
232 struct extent_buffer *leaf;
233 struct btrfs_root *new_root;
234 struct inode *dir = dentry->d_parent->d_inode;
238 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
247 ret = btrfs_reserve_metadata_space(root, 6);
251 trans = btrfs_start_transaction(root, 1);
254 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
259 leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
260 0, objectid, NULL, 0, 0, 0);
266 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
267 btrfs_set_header_bytenr(leaf, leaf->start);
268 btrfs_set_header_generation(leaf, trans->transid);
269 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
270 btrfs_set_header_owner(leaf, objectid);
272 write_extent_buffer(leaf, root->fs_info->fsid,
273 (unsigned long)btrfs_header_fsid(leaf),
275 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
276 (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
278 btrfs_mark_buffer_dirty(leaf);
280 inode_item = &root_item.inode;
281 memset(inode_item, 0, sizeof(*inode_item));
282 inode_item->generation = cpu_to_le64(1);
283 inode_item->size = cpu_to_le64(3);
284 inode_item->nlink = cpu_to_le32(1);
285 inode_item->nbytes = cpu_to_le64(root->leafsize);
286 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
288 btrfs_set_root_bytenr(&root_item, leaf->start);
289 btrfs_set_root_generation(&root_item, trans->transid);
290 btrfs_set_root_level(&root_item, 0);
291 btrfs_set_root_refs(&root_item, 1);
292 btrfs_set_root_used(&root_item, leaf->len);
293 btrfs_set_root_last_snapshot(&root_item, 0);
295 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
296 root_item.drop_level = 0;
298 btrfs_tree_unlock(leaf);
299 free_extent_buffer(leaf);
302 btrfs_set_root_dirid(&root_item, new_dirid);
304 key.objectid = objectid;
306 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
307 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
312 key.offset = (u64)-1;
313 new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
314 BUG_ON(IS_ERR(new_root));
316 btrfs_record_root_in_trans(trans, new_root);
318 ret = btrfs_create_subvol_root(trans, new_root, new_dirid,
319 BTRFS_I(dir)->block_group);
321 * insert the directory item
323 ret = btrfs_set_inode_index(dir, &index);
326 ret = btrfs_insert_dir_item(trans, root,
327 name, namelen, dir->i_ino, &key,
328 BTRFS_FT_DIR, index);
332 btrfs_i_size_write(dir, dir->i_size + namelen * 2);
333 ret = btrfs_update_inode(trans, root, dir);
336 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
337 objectid, root->root_key.objectid,
338 dir->i_ino, index, name, namelen);
342 d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
344 err = btrfs_commit_transaction(trans, root);
348 btrfs_unreserve_metadata_space(root, 6);
352 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
353 char *name, int namelen)
356 struct btrfs_pending_snapshot *pending_snapshot;
357 struct btrfs_trans_handle *trans;
369 ret = btrfs_reserve_metadata_space(root, 6);
373 pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
374 if (!pending_snapshot) {
376 btrfs_unreserve_metadata_space(root, 6);
379 pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
380 if (!pending_snapshot->name) {
382 kfree(pending_snapshot);
383 btrfs_unreserve_metadata_space(root, 6);
386 memcpy(pending_snapshot->name, name, namelen);
387 pending_snapshot->name[namelen] = '\0';
388 pending_snapshot->dentry = dentry;
389 trans = btrfs_start_transaction(root, 1);
391 pending_snapshot->root = root;
392 list_add(&pending_snapshot->list,
393 &trans->transaction->pending_snapshots);
394 ret = btrfs_commit_transaction(trans, root);
396 btrfs_unreserve_metadata_space(root, 6);
398 inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
400 ret = PTR_ERR(inode);
404 d_instantiate(dentry, inode);
410 /* copy of may_create in fs/namei.c() */
411 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
417 return inode_permission(dir, MAY_WRITE | MAY_EXEC);
421 * Create a new subvolume below @parent. This is largely modeled after
422 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
423 * inside this filesystem so it's quite a bit simpler.
425 static noinline int btrfs_mksubvol(struct path *parent,
426 char *name, int namelen,
427 struct btrfs_root *snap_src)
429 struct inode *dir = parent->dentry->d_inode;
430 struct dentry *dentry;
433 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
435 dentry = lookup_one_len(name, parent->dentry, namelen);
436 error = PTR_ERR(dentry);
444 error = mnt_want_write(parent->mnt);
448 error = btrfs_may_create(dir, dentry);
452 down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
454 if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
458 error = create_snapshot(snap_src, dentry,
461 error = create_subvol(BTRFS_I(dir)->root, dentry,
465 fsnotify_mkdir(dir, dentry);
467 up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
469 mnt_drop_write(parent->mnt);
473 mutex_unlock(&dir->i_mutex);
477 static int should_defrag_range(struct inode *inode, u64 start, u64 len,
478 int thresh, u64 *last_len, u64 *skip,
481 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
482 struct extent_map *em = NULL;
483 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
491 * make sure that once we start defragging and extent, we keep on
494 if (start < *defrag_end)
500 * hopefully we have this extent in the tree already, try without
501 * the full extent lock
503 read_lock(&em_tree->lock);
504 em = lookup_extent_mapping(em_tree, start, len);
505 read_unlock(&em_tree->lock);
508 /* get the big lock and read metadata off disk */
509 lock_extent(io_tree, start, start + len - 1, GFP_NOFS);
510 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
511 unlock_extent(io_tree, start, start + len - 1, GFP_NOFS);
517 /* this will cover holes, and inline extents */
518 if (em->block_start >= EXTENT_MAP_LAST_BYTE)
522 * we hit a real extent, if it is big don't bother defragging it again
524 if ((*last_len == 0 || *last_len >= thresh) && em->len >= thresh)
528 * last_len ends up being a counter of how many bytes we've defragged.
529 * every time we choose not to defrag an extent, we reset *last_len
530 * so that the next tiny extent will force a defrag.
532 * The end result of this is that tiny extents before a single big
533 * extent will force at least part of that big extent to be defragged.
537 *defrag_end = extent_map_end(em);
540 *skip = extent_map_end(em);
548 static int btrfs_defrag_file(struct file *file,
549 struct btrfs_ioctl_defrag_range_args *range)
551 struct inode *inode = fdentry(file)->d_inode;
552 struct btrfs_root *root = BTRFS_I(inode)->root;
553 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
554 struct btrfs_ordered_extent *ordered;
556 unsigned long last_index;
557 unsigned long ra_pages = root->fs_info->bdi.ra_pages;
558 unsigned long total_read = 0;
567 if (inode->i_size == 0)
570 if (range->start + range->len > range->start) {
571 last_index = min_t(u64, inode->i_size - 1,
572 range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
574 last_index = (inode->i_size - 1) >> PAGE_CACHE_SHIFT;
577 i = range->start >> PAGE_CACHE_SHIFT;
578 while (i <= last_index) {
579 if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
581 range->extent_thresh,
586 * the should_defrag function tells us how much to skip
587 * bump our counter by the suggested amount
589 next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
590 i = max(i + 1, next);
594 if (total_read % ra_pages == 0) {
595 btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
596 min(last_index, i + ra_pages - 1));
599 mutex_lock(&inode->i_mutex);
600 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
601 BTRFS_I(inode)->force_compress = 1;
603 ret = btrfs_check_data_free_space(root, inode, PAGE_CACHE_SIZE);
609 ret = btrfs_reserve_metadata_for_delalloc(root, inode, 1);
611 btrfs_free_reserved_data_space(root, inode,
617 if (inode->i_size == 0 ||
618 i > ((inode->i_size - 1) >> PAGE_CACHE_SHIFT)) {
620 goto err_reservations;
623 page = grab_cache_page(inode->i_mapping, i);
625 goto err_reservations;
627 if (!PageUptodate(page)) {
628 btrfs_readpage(NULL, page);
630 if (!PageUptodate(page)) {
632 page_cache_release(page);
633 goto err_reservations;
637 if (page->mapping != inode->i_mapping) {
639 page_cache_release(page);
643 wait_on_page_writeback(page);
645 if (PageDirty(page)) {
646 btrfs_free_reserved_data_space(root, inode,
651 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
652 page_end = page_start + PAGE_CACHE_SIZE - 1;
653 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
655 ordered = btrfs_lookup_ordered_extent(inode, page_start);
657 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
659 page_cache_release(page);
660 btrfs_start_ordered_extent(inode, ordered, 1);
661 btrfs_put_ordered_extent(ordered);
664 set_page_extent_mapped(page);
667 * this makes sure page_mkwrite is called on the
668 * page if it is dirtied again later
670 clear_page_dirty_for_io(page);
671 clear_extent_bits(&BTRFS_I(inode)->io_tree, page_start,
672 page_end, EXTENT_DIRTY | EXTENT_DELALLOC |
673 EXTENT_DO_ACCOUNTING, GFP_NOFS);
675 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
676 ClearPageChecked(page);
677 set_page_dirty(page);
678 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
682 page_cache_release(page);
683 mutex_unlock(&inode->i_mutex);
685 btrfs_unreserve_metadata_for_delalloc(root, inode, 1);
686 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
690 if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
691 filemap_flush(inode->i_mapping);
693 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
694 /* the filemap_flush will queue IO into the worker threads, but
695 * we have to make sure the IO is actually started and that
696 * ordered extents get created before we return
698 atomic_inc(&root->fs_info->async_submit_draining);
699 while (atomic_read(&root->fs_info->nr_async_submits) ||
700 atomic_read(&root->fs_info->async_delalloc_pages)) {
701 wait_event(root->fs_info->async_submit_wait,
702 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
703 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
705 atomic_dec(&root->fs_info->async_submit_draining);
707 mutex_lock(&inode->i_mutex);
708 BTRFS_I(inode)->force_compress = 0;
709 mutex_unlock(&inode->i_mutex);
715 mutex_unlock(&inode->i_mutex);
716 btrfs_free_reserved_data_space(root, inode, PAGE_CACHE_SIZE);
717 btrfs_unreserve_metadata_for_delalloc(root, inode, 1);
721 static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
727 struct btrfs_ioctl_vol_args *vol_args;
728 struct btrfs_trans_handle *trans;
729 struct btrfs_device *device = NULL;
736 if (root->fs_info->sb->s_flags & MS_RDONLY)
739 if (!capable(CAP_SYS_ADMIN))
742 vol_args = memdup_user(arg, sizeof(*vol_args));
743 if (IS_ERR(vol_args))
744 return PTR_ERR(vol_args);
746 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
747 namelen = strlen(vol_args->name);
749 mutex_lock(&root->fs_info->volume_mutex);
750 sizestr = vol_args->name;
751 devstr = strchr(sizestr, ':');
754 sizestr = devstr + 1;
756 devstr = vol_args->name;
757 devid = simple_strtoull(devstr, &end, 10);
758 printk(KERN_INFO "resizing devid %llu\n",
759 (unsigned long long)devid);
761 device = btrfs_find_device(root, devid, NULL, NULL);
763 printk(KERN_INFO "resizer unable to find device %llu\n",
764 (unsigned long long)devid);
768 if (!strcmp(sizestr, "max"))
769 new_size = device->bdev->bd_inode->i_size;
771 if (sizestr[0] == '-') {
774 } else if (sizestr[0] == '+') {
778 new_size = memparse(sizestr, NULL);
785 old_size = device->total_bytes;
788 if (new_size > old_size) {
792 new_size = old_size - new_size;
793 } else if (mod > 0) {
794 new_size = old_size + new_size;
797 if (new_size < 256 * 1024 * 1024) {
801 if (new_size > device->bdev->bd_inode->i_size) {
806 do_div(new_size, root->sectorsize);
807 new_size *= root->sectorsize;
809 printk(KERN_INFO "new size for %s is %llu\n",
810 device->name, (unsigned long long)new_size);
812 if (new_size > old_size) {
813 trans = btrfs_start_transaction(root, 1);
814 ret = btrfs_grow_device(trans, device, new_size);
815 btrfs_commit_transaction(trans, root);
817 ret = btrfs_shrink_device(device, new_size);
821 mutex_unlock(&root->fs_info->volume_mutex);
826 static noinline int btrfs_ioctl_snap_create(struct file *file,
827 void __user *arg, int subvol)
829 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
830 struct btrfs_ioctl_vol_args *vol_args;
831 struct file *src_file;
835 if (root->fs_info->sb->s_flags & MS_RDONLY)
838 vol_args = memdup_user(arg, sizeof(*vol_args));
839 if (IS_ERR(vol_args))
840 return PTR_ERR(vol_args);
842 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
843 namelen = strlen(vol_args->name);
844 if (strchr(vol_args->name, '/')) {
850 ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen,
853 struct inode *src_inode;
854 src_file = fget(vol_args->fd);
860 src_inode = src_file->f_path.dentry->d_inode;
861 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
862 printk(KERN_INFO "btrfs: Snapshot src from "
868 ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen,
869 BTRFS_I(src_inode)->root);
878 * helper to check if the subvolume references other subvolumes
880 static noinline int may_destroy_subvol(struct btrfs_root *root)
882 struct btrfs_path *path;
883 struct btrfs_key key;
886 path = btrfs_alloc_path();
890 key.objectid = root->root_key.objectid;
891 key.type = BTRFS_ROOT_REF_KEY;
892 key.offset = (u64)-1;
894 ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
901 if (path->slots[0] > 0) {
903 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
904 if (key.objectid == root->root_key.objectid &&
905 key.type == BTRFS_ROOT_REF_KEY)
909 btrfs_free_path(path);
913 static noinline int key_in_sk(struct btrfs_key *key,
914 struct btrfs_ioctl_search_key *sk)
916 struct btrfs_key test;
919 test.objectid = sk->min_objectid;
920 test.type = sk->min_type;
921 test.offset = sk->min_offset;
923 ret = btrfs_comp_cpu_keys(key, &test);
927 test.objectid = sk->max_objectid;
928 test.type = sk->max_type;
929 test.offset = sk->max_offset;
931 ret = btrfs_comp_cpu_keys(key, &test);
937 static noinline int copy_to_sk(struct btrfs_root *root,
938 struct btrfs_path *path,
939 struct btrfs_key *key,
940 struct btrfs_ioctl_search_key *sk,
942 unsigned long *sk_offset,
946 struct extent_buffer *leaf;
947 struct btrfs_ioctl_search_header sh;
948 unsigned long item_off;
949 unsigned long item_len;
956 leaf = path->nodes[0];
957 slot = path->slots[0];
958 nritems = btrfs_header_nritems(leaf);
960 if (btrfs_header_generation(leaf) > sk->max_transid) {
964 found_transid = btrfs_header_generation(leaf);
966 for (i = slot; i < nritems; i++) {
967 item_off = btrfs_item_ptr_offset(leaf, i);
968 item_len = btrfs_item_size_nr(leaf, i);
970 if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
973 if (sizeof(sh) + item_len + *sk_offset >
974 BTRFS_SEARCH_ARGS_BUFSIZE) {
979 btrfs_item_key_to_cpu(leaf, key, i);
980 if (!key_in_sk(key, sk))
983 sh.objectid = key->objectid;
984 sh.offset = key->offset;
987 sh.transid = found_transid;
989 /* copy search result header */
990 memcpy(buf + *sk_offset, &sh, sizeof(sh));
991 *sk_offset += sizeof(sh);
994 char *p = buf + *sk_offset;
996 read_extent_buffer(leaf, p,
998 *sk_offset += item_len;
1002 if (*num_found >= sk->nr_items)
1007 if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1009 else if (key->type < (u8)-1 && key->type < sk->max_type) {
1012 } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1019 *num_found += found;
1023 static noinline int search_ioctl(struct inode *inode,
1024 struct btrfs_ioctl_search_args *args)
1026 struct btrfs_root *root;
1027 struct btrfs_key key;
1028 struct btrfs_key max_key;
1029 struct btrfs_path *path;
1030 struct btrfs_ioctl_search_key *sk = &args->key;
1031 struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1034 unsigned long sk_offset = 0;
1036 path = btrfs_alloc_path();
1040 if (sk->tree_id == 0) {
1041 /* search the root of the inode that was passed */
1042 root = BTRFS_I(inode)->root;
1044 key.objectid = sk->tree_id;
1045 key.type = BTRFS_ROOT_ITEM_KEY;
1046 key.offset = (u64)-1;
1047 root = btrfs_read_fs_root_no_name(info, &key);
1049 printk(KERN_ERR "could not find root %llu\n",
1051 btrfs_free_path(path);
1056 key.objectid = sk->min_objectid;
1057 key.type = sk->min_type;
1058 key.offset = sk->min_offset;
1060 max_key.objectid = sk->max_objectid;
1061 max_key.type = sk->max_type;
1062 max_key.offset = sk->max_offset;
1064 path->keep_locks = 1;
1067 ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1074 ret = copy_to_sk(root, path, &key, sk, args->buf,
1075 &sk_offset, &num_found);
1076 btrfs_release_path(root, path);
1077 if (ret || num_found >= sk->nr_items)
1083 sk->nr_items = num_found;
1084 btrfs_free_path(path);
1088 static noinline int btrfs_ioctl_tree_search(struct file *file,
1091 struct btrfs_ioctl_search_args *args;
1092 struct inode *inode;
1095 if (!capable(CAP_SYS_ADMIN))
1098 args = kmalloc(sizeof(*args), GFP_KERNEL);
1102 if (copy_from_user(args, argp, sizeof(*args))) {
1106 inode = fdentry(file)->d_inode;
1107 ret = search_ioctl(inode, args);
1108 if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1115 * Search INODE_REFs to identify path name of 'dirid' directory
1116 * in a 'tree_id' tree. and sets path name to 'name'.
1118 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1119 u64 tree_id, u64 dirid, char *name)
1121 struct btrfs_root *root;
1122 struct btrfs_key key;
1128 struct btrfs_inode_ref *iref;
1129 struct extent_buffer *l;
1130 struct btrfs_path *path;
1132 if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1137 path = btrfs_alloc_path();
1141 ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1143 key.objectid = tree_id;
1144 key.type = BTRFS_ROOT_ITEM_KEY;
1145 key.offset = (u64)-1;
1146 root = btrfs_read_fs_root_no_name(info, &key);
1148 printk(KERN_ERR "could not find root %llu\n", tree_id);
1153 key.objectid = dirid;
1154 key.type = BTRFS_INODE_REF_KEY;
1155 key.offset = (u64)-1;
1158 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1163 slot = path->slots[0];
1164 if (ret > 0 && slot > 0)
1166 btrfs_item_key_to_cpu(l, &key, slot);
1168 if (ret > 0 && (key.objectid != dirid ||
1169 key.type != BTRFS_INODE_REF_KEY)) {
1174 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1175 len = btrfs_inode_ref_name_len(l, iref);
1177 total_len += len + 1;
1182 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1184 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1187 btrfs_release_path(root, path);
1188 key.objectid = key.offset;
1189 key.offset = (u64)-1;
1190 dirid = key.objectid;
1195 memcpy(name, ptr, total_len);
1196 name[total_len]='\0';
1199 btrfs_free_path(path);
1203 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1206 struct btrfs_ioctl_ino_lookup_args *args;
1207 struct inode *inode;
1210 if (!capable(CAP_SYS_ADMIN))
1213 args = kmalloc(sizeof(*args), GFP_KERNEL);
1217 if (copy_from_user(args, argp, sizeof(*args))) {
1221 inode = fdentry(file)->d_inode;
1223 if (args->treeid == 0)
1224 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
1226 ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
1227 args->treeid, args->objectid,
1230 if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1237 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
1240 struct dentry *parent = fdentry(file);
1241 struct dentry *dentry;
1242 struct inode *dir = parent->d_inode;
1243 struct inode *inode;
1244 struct btrfs_root *root = BTRFS_I(dir)->root;
1245 struct btrfs_root *dest = NULL;
1246 struct btrfs_ioctl_vol_args *vol_args;
1247 struct btrfs_trans_handle *trans;
1252 if (!capable(CAP_SYS_ADMIN))
1255 vol_args = memdup_user(arg, sizeof(*vol_args));
1256 if (IS_ERR(vol_args))
1257 return PTR_ERR(vol_args);
1259 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1260 namelen = strlen(vol_args->name);
1261 if (strchr(vol_args->name, '/') ||
1262 strncmp(vol_args->name, "..", namelen) == 0) {
1267 err = mnt_want_write(file->f_path.mnt);
1271 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
1272 dentry = lookup_one_len(vol_args->name, parent, namelen);
1273 if (IS_ERR(dentry)) {
1274 err = PTR_ERR(dentry);
1275 goto out_unlock_dir;
1278 if (!dentry->d_inode) {
1283 inode = dentry->d_inode;
1284 if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) {
1289 dest = BTRFS_I(inode)->root;
1291 mutex_lock(&inode->i_mutex);
1292 err = d_invalidate(dentry);
1296 down_write(&root->fs_info->subvol_sem);
1298 err = may_destroy_subvol(dest);
1302 trans = btrfs_start_transaction(root, 1);
1303 ret = btrfs_unlink_subvol(trans, root, dir,
1304 dest->root_key.objectid,
1305 dentry->d_name.name,
1306 dentry->d_name.len);
1309 btrfs_record_root_in_trans(trans, dest);
1311 memset(&dest->root_item.drop_progress, 0,
1312 sizeof(dest->root_item.drop_progress));
1313 dest->root_item.drop_level = 0;
1314 btrfs_set_root_refs(&dest->root_item, 0);
1316 ret = btrfs_insert_orphan_item(trans,
1317 root->fs_info->tree_root,
1318 dest->root_key.objectid);
1321 ret = btrfs_commit_transaction(trans, root);
1323 inode->i_flags |= S_DEAD;
1325 up_write(&root->fs_info->subvol_sem);
1327 mutex_unlock(&inode->i_mutex);
1329 shrink_dcache_sb(root->fs_info->sb);
1330 btrfs_invalidate_inodes(dest);
1336 mutex_unlock(&dir->i_mutex);
1337 mnt_drop_write(file->f_path.mnt);
1343 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
1345 struct inode *inode = fdentry(file)->d_inode;
1346 struct btrfs_root *root = BTRFS_I(inode)->root;
1347 struct btrfs_ioctl_defrag_range_args *range;
1350 ret = mnt_want_write(file->f_path.mnt);
1354 switch (inode->i_mode & S_IFMT) {
1356 if (!capable(CAP_SYS_ADMIN)) {
1360 btrfs_defrag_root(root, 0);
1361 btrfs_defrag_root(root->fs_info->extent_root, 0);
1364 if (!(file->f_mode & FMODE_WRITE)) {
1369 range = kzalloc(sizeof(*range), GFP_KERNEL);
1376 if (copy_from_user(range, argp,
1382 /* compression requires us to start the IO */
1383 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1384 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
1385 range->extent_thresh = (u32)-1;
1388 /* the rest are all set to zero by kzalloc */
1389 range->len = (u64)-1;
1391 btrfs_defrag_file(file, range);
1396 mnt_drop_write(file->f_path.mnt);
1400 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
1402 struct btrfs_ioctl_vol_args *vol_args;
1405 if (!capable(CAP_SYS_ADMIN))
1408 vol_args = memdup_user(arg, sizeof(*vol_args));
1409 if (IS_ERR(vol_args))
1410 return PTR_ERR(vol_args);
1412 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1413 ret = btrfs_init_new_device(root, vol_args->name);
1419 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
1421 struct btrfs_ioctl_vol_args *vol_args;
1424 if (!capable(CAP_SYS_ADMIN))
1427 if (root->fs_info->sb->s_flags & MS_RDONLY)
1430 vol_args = memdup_user(arg, sizeof(*vol_args));
1431 if (IS_ERR(vol_args))
1432 return PTR_ERR(vol_args);
1434 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1435 ret = btrfs_rm_device(root, vol_args->name);
1441 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
1442 u64 off, u64 olen, u64 destoff)
1444 struct inode *inode = fdentry(file)->d_inode;
1445 struct btrfs_root *root = BTRFS_I(inode)->root;
1446 struct file *src_file;
1448 struct btrfs_trans_handle *trans;
1449 struct btrfs_path *path;
1450 struct extent_buffer *leaf;
1452 struct btrfs_key key;
1457 u64 bs = root->fs_info->sb->s_blocksize;
1462 * - split compressed inline extents. annoying: we need to
1463 * decompress into destination's address_space (the file offset
1464 * may change, so source mapping won't do), then recompress (or
1465 * otherwise reinsert) a subrange.
1466 * - allow ranges within the same file to be cloned (provided
1467 * they don't overlap)?
1470 /* the destination must be opened for writing */
1471 if (!(file->f_mode & FMODE_WRITE))
1474 ret = mnt_want_write(file->f_path.mnt);
1478 src_file = fget(srcfd);
1481 goto out_drop_write;
1483 src = src_file->f_dentry->d_inode;
1490 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
1494 if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
1498 buf = vmalloc(btrfs_level_size(root, 0));
1502 path = btrfs_alloc_path();
1510 mutex_lock(&inode->i_mutex);
1511 mutex_lock(&src->i_mutex);
1513 mutex_lock(&src->i_mutex);
1514 mutex_lock(&inode->i_mutex);
1517 /* determine range to clone */
1519 if (off >= src->i_size || off + len > src->i_size)
1522 olen = len = src->i_size - off;
1523 /* if we extend to eof, continue to block boundary */
1524 if (off + len == src->i_size)
1525 len = ((src->i_size + bs-1) & ~(bs-1))
1528 /* verify the end result is block aligned */
1529 if ((off & (bs-1)) ||
1530 ((off + len) & (bs-1)))
1533 /* do any pending delalloc/csum calc on src, one way or
1534 another, and lock file content */
1536 struct btrfs_ordered_extent *ordered;
1537 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1538 ordered = btrfs_lookup_first_ordered_extent(inode, off+len);
1539 if (BTRFS_I(src)->delalloc_bytes == 0 && !ordered)
1541 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1543 btrfs_put_ordered_extent(ordered);
1544 btrfs_wait_ordered_range(src, off, off+len);
1547 trans = btrfs_start_transaction(root, 1);
1550 /* punch hole in destination first */
1551 btrfs_drop_extents(trans, inode, off, off + len, &hint_byte, 1);
1554 key.objectid = src->i_ino;
1555 key.type = BTRFS_EXTENT_DATA_KEY;
1560 * note the key will change type as we walk through the
1563 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
1567 nritems = btrfs_header_nritems(path->nodes[0]);
1568 if (path->slots[0] >= nritems) {
1569 ret = btrfs_next_leaf(root, path);
1574 nritems = btrfs_header_nritems(path->nodes[0]);
1576 leaf = path->nodes[0];
1577 slot = path->slots[0];
1579 btrfs_item_key_to_cpu(leaf, &key, slot);
1580 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
1581 key.objectid != src->i_ino)
1584 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
1585 struct btrfs_file_extent_item *extent;
1588 struct btrfs_key new_key;
1589 u64 disko = 0, diskl = 0;
1590 u64 datao = 0, datal = 0;
1593 size = btrfs_item_size_nr(leaf, slot);
1594 read_extent_buffer(leaf, buf,
1595 btrfs_item_ptr_offset(leaf, slot),
1598 extent = btrfs_item_ptr(leaf, slot,
1599 struct btrfs_file_extent_item);
1600 comp = btrfs_file_extent_compression(leaf, extent);
1601 type = btrfs_file_extent_type(leaf, extent);
1602 if (type == BTRFS_FILE_EXTENT_REG ||
1603 type == BTRFS_FILE_EXTENT_PREALLOC) {
1604 disko = btrfs_file_extent_disk_bytenr(leaf,
1606 diskl = btrfs_file_extent_disk_num_bytes(leaf,
1608 datao = btrfs_file_extent_offset(leaf, extent);
1609 datal = btrfs_file_extent_num_bytes(leaf,
1611 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1612 /* take upper bound, may be compressed */
1613 datal = btrfs_file_extent_ram_bytes(leaf,
1616 btrfs_release_path(root, path);
1618 if (key.offset + datal < off ||
1619 key.offset >= off+len)
1622 memcpy(&new_key, &key, sizeof(new_key));
1623 new_key.objectid = inode->i_ino;
1624 new_key.offset = key.offset + destoff - off;
1626 if (type == BTRFS_FILE_EXTENT_REG ||
1627 type == BTRFS_FILE_EXTENT_PREALLOC) {
1628 ret = btrfs_insert_empty_item(trans, root, path,
1633 leaf = path->nodes[0];
1634 slot = path->slots[0];
1635 write_extent_buffer(leaf, buf,
1636 btrfs_item_ptr_offset(leaf, slot),
1639 extent = btrfs_item_ptr(leaf, slot,
1640 struct btrfs_file_extent_item);
1642 if (off > key.offset) {
1643 datao += off - key.offset;
1644 datal -= off - key.offset;
1647 if (key.offset + datal > off + len)
1648 datal = off + len - key.offset;
1650 /* disko == 0 means it's a hole */
1654 btrfs_set_file_extent_offset(leaf, extent,
1656 btrfs_set_file_extent_num_bytes(leaf, extent,
1659 inode_add_bytes(inode, datal);
1660 ret = btrfs_inc_extent_ref(trans, root,
1662 root->root_key.objectid,
1664 new_key.offset - datao);
1667 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1670 if (off > key.offset) {
1671 skip = off - key.offset;
1672 new_key.offset += skip;
1675 if (key.offset + datal > off+len)
1676 trim = key.offset + datal - (off+len);
1678 if (comp && (skip || trim)) {
1682 size -= skip + trim;
1683 datal -= skip + trim;
1684 ret = btrfs_insert_empty_item(trans, root, path,
1691 btrfs_file_extent_calc_inline_size(0);
1692 memmove(buf+start, buf+start+skip,
1696 leaf = path->nodes[0];
1697 slot = path->slots[0];
1698 write_extent_buffer(leaf, buf,
1699 btrfs_item_ptr_offset(leaf, slot),
1701 inode_add_bytes(inode, datal);
1704 btrfs_mark_buffer_dirty(leaf);
1708 btrfs_release_path(root, path);
1713 btrfs_release_path(root, path);
1715 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1716 if (destoff + olen > inode->i_size)
1717 btrfs_i_size_write(inode, destoff + olen);
1718 BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
1719 ret = btrfs_update_inode(trans, root, inode);
1721 btrfs_end_transaction(trans, root);
1722 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1724 vmtruncate(inode, 0);
1726 mutex_unlock(&src->i_mutex);
1727 mutex_unlock(&inode->i_mutex);
1729 btrfs_free_path(path);
1733 mnt_drop_write(file->f_path.mnt);
1737 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
1739 struct btrfs_ioctl_clone_range_args args;
1741 if (copy_from_user(&args, argp, sizeof(args)))
1743 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
1744 args.src_length, args.dest_offset);
1748 * there are many ways the trans_start and trans_end ioctls can lead
1749 * to deadlocks. They should only be used by applications that
1750 * basically own the machine, and have a very in depth understanding
1751 * of all the possible deadlocks and enospc problems.
1753 static long btrfs_ioctl_trans_start(struct file *file)
1755 struct inode *inode = fdentry(file)->d_inode;
1756 struct btrfs_root *root = BTRFS_I(inode)->root;
1757 struct btrfs_trans_handle *trans;
1761 if (!capable(CAP_SYS_ADMIN))
1765 if (file->private_data)
1768 ret = mnt_want_write(file->f_path.mnt);
1772 mutex_lock(&root->fs_info->trans_mutex);
1773 root->fs_info->open_ioctl_trans++;
1774 mutex_unlock(&root->fs_info->trans_mutex);
1777 trans = btrfs_start_ioctl_transaction(root, 0);
1781 file->private_data = trans;
1785 mutex_lock(&root->fs_info->trans_mutex);
1786 root->fs_info->open_ioctl_trans--;
1787 mutex_unlock(&root->fs_info->trans_mutex);
1788 mnt_drop_write(file->f_path.mnt);
1793 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
1795 struct inode *inode = fdentry(file)->d_inode;
1796 struct btrfs_root *root = BTRFS_I(inode)->root;
1797 struct btrfs_root *new_root;
1798 struct btrfs_dir_item *di;
1799 struct btrfs_trans_handle *trans;
1800 struct btrfs_path *path;
1801 struct btrfs_key location;
1802 struct btrfs_disk_key disk_key;
1803 struct btrfs_super_block *disk_super;
1808 if (!capable(CAP_SYS_ADMIN))
1811 if (copy_from_user(&objectid, argp, sizeof(objectid)))
1815 objectid = root->root_key.objectid;
1817 location.objectid = objectid;
1818 location.type = BTRFS_ROOT_ITEM_KEY;
1819 location.offset = (u64)-1;
1821 new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
1822 if (IS_ERR(new_root))
1823 return PTR_ERR(new_root);
1825 if (btrfs_root_refs(&new_root->root_item) == 0)
1828 path = btrfs_alloc_path();
1831 path->leave_spinning = 1;
1833 trans = btrfs_start_transaction(root, 1);
1835 btrfs_free_path(path);
1839 dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
1840 di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
1841 dir_id, "default", 7, 1);
1843 btrfs_free_path(path);
1844 btrfs_end_transaction(trans, root);
1845 printk(KERN_ERR "Umm, you don't have the default dir item, "
1846 "this isn't going to work\n");
1850 btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
1851 btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
1852 btrfs_mark_buffer_dirty(path->nodes[0]);
1853 btrfs_free_path(path);
1855 disk_super = &root->fs_info->super_copy;
1856 features = btrfs_super_incompat_flags(disk_super);
1857 if (!(features & BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)) {
1858 features |= BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL;
1859 btrfs_set_super_incompat_flags(disk_super, features);
1861 btrfs_end_transaction(trans, root);
1866 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
1868 struct btrfs_ioctl_space_args space_args;
1869 struct btrfs_ioctl_space_info space;
1870 struct btrfs_ioctl_space_info *dest;
1871 struct btrfs_ioctl_space_info *dest_orig;
1872 struct btrfs_ioctl_space_info *user_dest;
1873 struct btrfs_space_info *info;
1878 if (copy_from_user(&space_args,
1879 (struct btrfs_ioctl_space_args __user *)arg,
1880 sizeof(space_args)))
1883 /* first we count slots */
1885 list_for_each_entry_rcu(info, &root->fs_info->space_info, list)
1889 /* space_slots == 0 means they are asking for a count */
1890 if (space_args.space_slots == 0) {
1891 space_args.total_spaces = slot_count;
1894 alloc_size = sizeof(*dest) * slot_count;
1895 /* we generally have at most 6 or so space infos, one for each raid
1896 * level. So, a whole page should be more than enough for everyone
1898 if (alloc_size > PAGE_CACHE_SIZE)
1901 space_args.total_spaces = 0;
1902 dest = kmalloc(alloc_size, GFP_NOFS);
1907 /* now we have a buffer to copy into */
1909 list_for_each_entry_rcu(info, &root->fs_info->space_info, list) {
1910 /* make sure we don't copy more than we allocated
1913 if (slot_count == 0)
1917 /* make sure userland has enough room in their buffer */
1918 if (space_args.total_spaces >= space_args.space_slots)
1921 space.flags = info->flags;
1922 space.total_bytes = info->total_bytes;
1923 space.used_bytes = info->bytes_used;
1924 memcpy(dest, &space, sizeof(space));
1926 space_args.total_spaces++;
1930 user_dest = (struct btrfs_ioctl_space_info *)
1931 (arg + sizeof(struct btrfs_ioctl_space_args));
1933 if (copy_to_user(user_dest, dest_orig, alloc_size))
1938 if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
1945 * there are many ways the trans_start and trans_end ioctls can lead
1946 * to deadlocks. They should only be used by applications that
1947 * basically own the machine, and have a very in depth understanding
1948 * of all the possible deadlocks and enospc problems.
1950 long btrfs_ioctl_trans_end(struct file *file)
1952 struct inode *inode = fdentry(file)->d_inode;
1953 struct btrfs_root *root = BTRFS_I(inode)->root;
1954 struct btrfs_trans_handle *trans;
1956 trans = file->private_data;
1959 file->private_data = NULL;
1961 btrfs_end_transaction(trans, root);
1963 mutex_lock(&root->fs_info->trans_mutex);
1964 root->fs_info->open_ioctl_trans--;
1965 mutex_unlock(&root->fs_info->trans_mutex);
1967 mnt_drop_write(file->f_path.mnt);
1971 long btrfs_ioctl(struct file *file, unsigned int
1972 cmd, unsigned long arg)
1974 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
1975 void __user *argp = (void __user *)arg;
1978 case FS_IOC_GETFLAGS:
1979 return btrfs_ioctl_getflags(file, argp);
1980 case FS_IOC_SETFLAGS:
1981 return btrfs_ioctl_setflags(file, argp);
1982 case FS_IOC_GETVERSION:
1983 return btrfs_ioctl_getversion(file, argp);
1984 case BTRFS_IOC_SNAP_CREATE:
1985 return btrfs_ioctl_snap_create(file, argp, 0);
1986 case BTRFS_IOC_SUBVOL_CREATE:
1987 return btrfs_ioctl_snap_create(file, argp, 1);
1988 case BTRFS_IOC_SNAP_DESTROY:
1989 return btrfs_ioctl_snap_destroy(file, argp);
1990 case BTRFS_IOC_DEFAULT_SUBVOL:
1991 return btrfs_ioctl_default_subvol(file, argp);
1992 case BTRFS_IOC_DEFRAG:
1993 return btrfs_ioctl_defrag(file, NULL);
1994 case BTRFS_IOC_DEFRAG_RANGE:
1995 return btrfs_ioctl_defrag(file, argp);
1996 case BTRFS_IOC_RESIZE:
1997 return btrfs_ioctl_resize(root, argp);
1998 case BTRFS_IOC_ADD_DEV:
1999 return btrfs_ioctl_add_dev(root, argp);
2000 case BTRFS_IOC_RM_DEV:
2001 return btrfs_ioctl_rm_dev(root, argp);
2002 case BTRFS_IOC_BALANCE:
2003 return btrfs_balance(root->fs_info->dev_root);
2004 case BTRFS_IOC_CLONE:
2005 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
2006 case BTRFS_IOC_CLONE_RANGE:
2007 return btrfs_ioctl_clone_range(file, argp);
2008 case BTRFS_IOC_TRANS_START:
2009 return btrfs_ioctl_trans_start(file);
2010 case BTRFS_IOC_TRANS_END:
2011 return btrfs_ioctl_trans_end(file);
2012 case BTRFS_IOC_TREE_SEARCH:
2013 return btrfs_ioctl_tree_search(file, argp);
2014 case BTRFS_IOC_INO_LOOKUP:
2015 return btrfs_ioctl_ino_lookup(file, argp);
2016 case BTRFS_IOC_SPACE_INFO:
2017 return btrfs_ioctl_space_info(root, argp);
2018 case BTRFS_IOC_SYNC:
2019 btrfs_sync_fs(file->f_dentry->d_sb, 1);