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Btrfs: Full back reference support
[deliverable/linux.git] / fs / btrfs / ioctl.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
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.
7 *
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.
12 *
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.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/smp_lock.h>
30 #include <linux/backing-dev.h>
31 #include <linux/mpage.h>
32 #include <linux/swap.h>
33 #include <linux/writeback.h>
34 #include <linux/statfs.h>
35 #include <linux/compat.h>
36 #include <linux/bit_spinlock.h>
37 #include <linux/version.h>
38 #include <linux/xattr.h>
39 #include <linux/vmalloc.h>
40 #include "ctree.h"
41 #include "disk-io.h"
42 #include "transaction.h"
43 #include "btrfs_inode.h"
44 #include "ioctl.h"
45 #include "print-tree.h"
46 #include "volumes.h"
47 #include "locking.h"
48
49
50
51 static noinline int create_subvol(struct btrfs_root *root, char *name,
52 int namelen)
53 {
54 struct btrfs_trans_handle *trans;
55 struct btrfs_key key;
56 struct btrfs_root_item root_item;
57 struct btrfs_inode_item *inode_item;
58 struct extent_buffer *leaf;
59 struct btrfs_root *new_root = root;
60 struct inode *dir;
61 int ret;
62 int err;
63 u64 objectid;
64 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
65 unsigned long nr = 1;
66
67 ret = btrfs_check_free_space(root, 1, 0);
68 if (ret)
69 goto fail_commit;
70
71 trans = btrfs_start_transaction(root, 1);
72 BUG_ON(!trans);
73
74 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
75 0, &objectid);
76 if (ret)
77 goto fail;
78
79 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
80 objectid, trans->transid, 0, 0, 0);
81 if (IS_ERR(leaf)) {
82 ret = PTR_ERR(leaf);
83 goto fail;
84 }
85
86 btrfs_set_header_nritems(leaf, 0);
87 btrfs_set_header_level(leaf, 0);
88 btrfs_set_header_bytenr(leaf, leaf->start);
89 btrfs_set_header_generation(leaf, trans->transid);
90 btrfs_set_header_owner(leaf, objectid);
91
92 write_extent_buffer(leaf, root->fs_info->fsid,
93 (unsigned long)btrfs_header_fsid(leaf),
94 BTRFS_FSID_SIZE);
95 btrfs_mark_buffer_dirty(leaf);
96
97 inode_item = &root_item.inode;
98 memset(inode_item, 0, sizeof(*inode_item));
99 inode_item->generation = cpu_to_le64(1);
100 inode_item->size = cpu_to_le64(3);
101 inode_item->nlink = cpu_to_le32(1);
102 inode_item->nblocks = cpu_to_le64(1);
103 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
104
105 btrfs_set_root_bytenr(&root_item, leaf->start);
106 btrfs_set_root_level(&root_item, 0);
107 btrfs_set_root_refs(&root_item, 1);
108 btrfs_set_root_used(&root_item, 0);
109
110 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
111 root_item.drop_level = 0;
112
113 btrfs_tree_unlock(leaf);
114 free_extent_buffer(leaf);
115 leaf = NULL;
116
117 btrfs_set_root_dirid(&root_item, new_dirid);
118
119 key.objectid = objectid;
120 key.offset = 1;
121 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
122 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
123 &root_item);
124 if (ret)
125 goto fail;
126
127 /*
128 * insert the directory item
129 */
130 key.offset = (u64)-1;
131 dir = root->fs_info->sb->s_root->d_inode;
132 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
133 name, namelen, dir->i_ino, &key,
134 BTRFS_FT_DIR, 0);
135 if (ret)
136 goto fail;
137
138 ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
139 name, namelen, objectid,
140 root->fs_info->sb->s_root->d_inode->i_ino, 0);
141 if (ret)
142 goto fail;
143
144 ret = btrfs_commit_transaction(trans, root);
145 if (ret)
146 goto fail_commit;
147
148 new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
149 BUG_ON(!new_root);
150
151 trans = btrfs_start_transaction(new_root, 1);
152 BUG_ON(!trans);
153
154 ret = btrfs_create_subvol_root(new_root, trans, new_dirid,
155 BTRFS_I(dir)->block_group);
156 if (ret)
157 goto fail;
158
159 /* Invalidate existing dcache entry for new subvolume. */
160 btrfs_invalidate_dcache_root(root, name, namelen);
161
162 fail:
163 nr = trans->blocks_used;
164 err = btrfs_commit_transaction(trans, new_root);
165 if (err && !ret)
166 ret = err;
167 fail_commit:
168 btrfs_btree_balance_dirty(root, nr);
169 return ret;
170 }
171
172 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
173 {
174 struct btrfs_pending_snapshot *pending_snapshot;
175 struct btrfs_trans_handle *trans;
176 int ret;
177 int err;
178 unsigned long nr = 0;
179
180 if (!root->ref_cows)
181 return -EINVAL;
182
183 ret = btrfs_check_free_space(root, 1, 0);
184 if (ret)
185 goto fail_unlock;
186
187 pending_snapshot = kmalloc(sizeof(*pending_snapshot), GFP_NOFS);
188 if (!pending_snapshot) {
189 ret = -ENOMEM;
190 goto fail_unlock;
191 }
192 pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
193 if (!pending_snapshot->name) {
194 ret = -ENOMEM;
195 kfree(pending_snapshot);
196 goto fail_unlock;
197 }
198 memcpy(pending_snapshot->name, name, namelen);
199 pending_snapshot->name[namelen] = '\0';
200 trans = btrfs_start_transaction(root, 1);
201 BUG_ON(!trans);
202 pending_snapshot->root = root;
203 list_add(&pending_snapshot->list,
204 &trans->transaction->pending_snapshots);
205 ret = btrfs_update_inode(trans, root, root->inode);
206 err = btrfs_commit_transaction(trans, root);
207
208 fail_unlock:
209 btrfs_btree_balance_dirty(root, nr);
210 return ret;
211 }
212
213 int btrfs_defrag_file(struct file *file)
214 {
215 struct inode *inode = fdentry(file)->d_inode;
216 struct btrfs_root *root = BTRFS_I(inode)->root;
217 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
218 struct btrfs_ordered_extent *ordered;
219 struct page *page;
220 unsigned long last_index;
221 unsigned long ra_pages = root->fs_info->bdi.ra_pages;
222 unsigned long total_read = 0;
223 u64 page_start;
224 u64 page_end;
225 unsigned long i;
226 int ret;
227
228 ret = btrfs_check_free_space(root, inode->i_size, 0);
229 if (ret)
230 return -ENOSPC;
231
232 mutex_lock(&inode->i_mutex);
233 last_index = inode->i_size >> PAGE_CACHE_SHIFT;
234 for (i = 0; i <= last_index; i++) {
235 if (total_read % ra_pages == 0) {
236 btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
237 min(last_index, i + ra_pages - 1));
238 }
239 total_read++;
240 again:
241 page = grab_cache_page(inode->i_mapping, i);
242 if (!page)
243 goto out_unlock;
244 if (!PageUptodate(page)) {
245 btrfs_readpage(NULL, page);
246 lock_page(page);
247 if (!PageUptodate(page)) {
248 unlock_page(page);
249 page_cache_release(page);
250 goto out_unlock;
251 }
252 }
253
254 wait_on_page_writeback(page);
255
256 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
257 page_end = page_start + PAGE_CACHE_SIZE - 1;
258 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
259
260 ordered = btrfs_lookup_ordered_extent(inode, page_start);
261 if (ordered) {
262 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
263 unlock_page(page);
264 page_cache_release(page);
265 btrfs_start_ordered_extent(inode, ordered, 1);
266 btrfs_put_ordered_extent(ordered);
267 goto again;
268 }
269 set_page_extent_mapped(page);
270
271 /*
272 * this makes sure page_mkwrite is called on the
273 * page if it is dirtied again later
274 */
275 clear_page_dirty_for_io(page);
276
277 btrfs_set_extent_delalloc(inode, page_start, page_end);
278
279 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
280 set_page_dirty(page);
281 unlock_page(page);
282 page_cache_release(page);
283 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
284 }
285
286 out_unlock:
287 mutex_unlock(&inode->i_mutex);
288 return 0;
289 }
290
291 /*
292 * Called inside transaction, so use GFP_NOFS
293 */
294
295 static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
296 {
297 u64 new_size;
298 u64 old_size;
299 u64 devid = 1;
300 struct btrfs_ioctl_vol_args *vol_args;
301 struct btrfs_trans_handle *trans;
302 struct btrfs_device *device = NULL;
303 char *sizestr;
304 char *devstr = NULL;
305 int ret = 0;
306 int namelen;
307 int mod = 0;
308
309 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
310
311 if (!vol_args)
312 return -ENOMEM;
313
314 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
315 ret = -EFAULT;
316 goto out;
317 }
318
319 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
320 namelen = strlen(vol_args->name);
321
322 mutex_lock(&root->fs_info->volume_mutex);
323 sizestr = vol_args->name;
324 devstr = strchr(sizestr, ':');
325 if (devstr) {
326 char *end;
327 sizestr = devstr + 1;
328 *devstr = '\0';
329 devstr = vol_args->name;
330 devid = simple_strtoull(devstr, &end, 10);
331 printk(KERN_INFO "resizing devid %llu\n", devid);
332 }
333 device = btrfs_find_device(root, devid, NULL);
334 if (!device) {
335 printk(KERN_INFO "resizer unable to find device %llu\n", devid);
336 ret = -EINVAL;
337 goto out_unlock;
338 }
339 if (!strcmp(sizestr, "max"))
340 new_size = device->bdev->bd_inode->i_size;
341 else {
342 if (sizestr[0] == '-') {
343 mod = -1;
344 sizestr++;
345 } else if (sizestr[0] == '+') {
346 mod = 1;
347 sizestr++;
348 }
349 new_size = btrfs_parse_size(sizestr);
350 if (new_size == 0) {
351 ret = -EINVAL;
352 goto out_unlock;
353 }
354 }
355
356 old_size = device->total_bytes;
357
358 if (mod < 0) {
359 if (new_size > old_size) {
360 ret = -EINVAL;
361 goto out_unlock;
362 }
363 new_size = old_size - new_size;
364 } else if (mod > 0) {
365 new_size = old_size + new_size;
366 }
367
368 if (new_size < 256 * 1024 * 1024) {
369 ret = -EINVAL;
370 goto out_unlock;
371 }
372 if (new_size > device->bdev->bd_inode->i_size) {
373 ret = -EFBIG;
374 goto out_unlock;
375 }
376
377 do_div(new_size, root->sectorsize);
378 new_size *= root->sectorsize;
379
380 printk(KERN_INFO "new size for %s is %llu\n",
381 device->name, (unsigned long long)new_size);
382
383 if (new_size > old_size) {
384 trans = btrfs_start_transaction(root, 1);
385 ret = btrfs_grow_device(trans, device, new_size);
386 btrfs_commit_transaction(trans, root);
387 } else {
388 ret = btrfs_shrink_device(device, new_size);
389 }
390
391 out_unlock:
392 mutex_unlock(&root->fs_info->volume_mutex);
393 out:
394 kfree(vol_args);
395 return ret;
396 }
397
398 static noinline int btrfs_ioctl_snap_create(struct btrfs_root *root,
399 void __user *arg)
400 {
401 struct btrfs_ioctl_vol_args *vol_args;
402 struct btrfs_dir_item *di;
403 struct btrfs_path *path;
404 u64 root_dirid;
405 int namelen;
406 int ret;
407
408 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
409
410 if (!vol_args)
411 return -ENOMEM;
412
413 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
414 ret = -EFAULT;
415 goto out;
416 }
417
418 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
419 namelen = strlen(vol_args->name);
420 if (strchr(vol_args->name, '/')) {
421 ret = -EINVAL;
422 goto out;
423 }
424
425 path = btrfs_alloc_path();
426 if (!path) {
427 ret = -ENOMEM;
428 goto out;
429 }
430
431 root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
432 di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
433 path, root_dirid,
434 vol_args->name, namelen, 0);
435 btrfs_free_path(path);
436
437 if (di && !IS_ERR(di)) {
438 ret = -EEXIST;
439 goto out;
440 }
441
442 if (IS_ERR(di)) {
443 ret = PTR_ERR(di);
444 goto out;
445 }
446
447 mutex_lock(&root->fs_info->drop_mutex);
448 if (root == root->fs_info->tree_root)
449 ret = create_subvol(root, vol_args->name, namelen);
450 else
451 ret = create_snapshot(root, vol_args->name, namelen);
452 mutex_unlock(&root->fs_info->drop_mutex);
453 out:
454 kfree(vol_args);
455 return ret;
456 }
457
458 static int btrfs_ioctl_defrag(struct file *file)
459 {
460 struct inode *inode = fdentry(file)->d_inode;
461 struct btrfs_root *root = BTRFS_I(inode)->root;
462
463 switch (inode->i_mode & S_IFMT) {
464 case S_IFDIR:
465 btrfs_defrag_root(root, 0);
466 btrfs_defrag_root(root->fs_info->extent_root, 0);
467 break;
468 case S_IFREG:
469 btrfs_defrag_file(file);
470 break;
471 }
472
473 return 0;
474 }
475
476 long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
477 {
478 struct btrfs_ioctl_vol_args *vol_args;
479 int ret;
480
481 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
482
483 if (!vol_args)
484 return -ENOMEM;
485
486 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
487 ret = -EFAULT;
488 goto out;
489 }
490 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
491 ret = btrfs_init_new_device(root, vol_args->name);
492
493 out:
494 kfree(vol_args);
495 return ret;
496 }
497
498 long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
499 {
500 struct btrfs_ioctl_vol_args *vol_args;
501 int ret;
502
503 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
504
505 if (!vol_args)
506 return -ENOMEM;
507
508 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
509 ret = -EFAULT;
510 goto out;
511 }
512 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
513 ret = btrfs_rm_device(root, vol_args->name);
514
515 out:
516 kfree(vol_args);
517 return ret;
518 }
519
520 long btrfs_ioctl_clone(struct file *file, unsigned long src_fd)
521 {
522 struct inode *inode = fdentry(file)->d_inode;
523 struct btrfs_root *root = BTRFS_I(inode)->root;
524 struct file *src_file;
525 struct inode *src;
526 struct btrfs_trans_handle *trans;
527 struct btrfs_path *path;
528 struct extent_buffer *leaf;
529 char *buf;
530 struct btrfs_key key;
531 u32 nritems;
532 int slot;
533 int ret;
534
535 src_file = fget(src_fd);
536 if (!src_file)
537 return -EBADF;
538 src = src_file->f_dentry->d_inode;
539
540 ret = -EISDIR;
541 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
542 goto out_fput;
543
544 ret = -EXDEV;
545 if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
546 goto out_fput;
547
548 ret = -ENOMEM;
549 buf = vmalloc(btrfs_level_size(root, 0));
550 if (!buf)
551 goto out_fput;
552
553 path = btrfs_alloc_path();
554 if (!path) {
555 vfree(buf);
556 goto out_fput;
557 }
558 path->reada = 2;
559
560 if (inode < src) {
561 mutex_lock(&inode->i_mutex);
562 mutex_lock(&src->i_mutex);
563 } else {
564 mutex_lock(&src->i_mutex);
565 mutex_lock(&inode->i_mutex);
566 }
567
568 ret = -ENOTEMPTY;
569 if (inode->i_size)
570 goto out_unlock;
571
572 /* do any pending delalloc/csum calc on src, one way or
573 another, and lock file content */
574 while (1) {
575 struct btrfs_ordered_extent *ordered;
576 lock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS);
577 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
578 if (BTRFS_I(src)->delalloc_bytes == 0 && !ordered)
579 break;
580 unlock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS);
581 if (ordered)
582 btrfs_put_ordered_extent(ordered);
583 btrfs_wait_ordered_range(src, 0, (u64)-1);
584 }
585
586 trans = btrfs_start_transaction(root, 1);
587 BUG_ON(!trans);
588
589 key.objectid = src->i_ino;
590 key.type = BTRFS_EXTENT_DATA_KEY;
591 key.offset = 0;
592
593 while (1) {
594 /*
595 * note the key will change type as we walk through the
596 * tree.
597 */
598 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
599 if (ret < 0)
600 goto out;
601
602 nritems = btrfs_header_nritems(path->nodes[0]);
603 if (path->slots[0] >= nritems) {
604 ret = btrfs_next_leaf(root, path);
605 if (ret < 0)
606 goto out;
607 if (ret > 0)
608 break;
609 nritems = btrfs_header_nritems(path->nodes[0]);
610 }
611 leaf = path->nodes[0];
612 slot = path->slots[0];
613
614 btrfs_item_key_to_cpu(leaf, &key, slot);
615 if (btrfs_key_type(&key) > BTRFS_CSUM_ITEM_KEY ||
616 key.objectid != src->i_ino)
617 break;
618
619 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY ||
620 btrfs_key_type(&key) == BTRFS_CSUM_ITEM_KEY) {
621 u32 size;
622 struct btrfs_key new_key;
623
624 size = btrfs_item_size_nr(leaf, slot);
625 read_extent_buffer(leaf, buf,
626 btrfs_item_ptr_offset(leaf, slot),
627 size);
628 btrfs_release_path(root, path);
629
630 memcpy(&new_key, &key, sizeof(new_key));
631 new_key.objectid = inode->i_ino;
632 ret = btrfs_insert_empty_item(trans, root, path,
633 &new_key, size);
634 if (ret)
635 goto out;
636
637 leaf = path->nodes[0];
638 slot = path->slots[0];
639 write_extent_buffer(leaf, buf,
640 btrfs_item_ptr_offset(leaf, slot),
641 size);
642 btrfs_mark_buffer_dirty(leaf);
643 }
644
645 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
646 struct btrfs_file_extent_item *extent;
647 int found_type;
648
649 extent = btrfs_item_ptr(leaf, slot,
650 struct btrfs_file_extent_item);
651 found_type = btrfs_file_extent_type(leaf, extent);
652 if (found_type == BTRFS_FILE_EXTENT_REG) {
653 u64 ds = btrfs_file_extent_disk_bytenr(leaf,
654 extent);
655 u64 dl = btrfs_file_extent_disk_num_bytes(leaf,
656 extent);
657 /* ds == 0 means there's a hole */
658 if (ds != 0) {
659 ret = btrfs_inc_extent_ref(trans, root,
660 ds, dl, leaf->start,
661 root->root_key.objectid,
662 trans->transid,
663 inode->i_ino, key.offset);
664 BUG_ON(ret);
665 }
666 }
667 }
668 btrfs_release_path(root, path);
669 key.offset++;
670 }
671 ret = 0;
672 out:
673 btrfs_release_path(root, path);
674 if (ret == 0) {
675 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
676 inode->i_blocks = src->i_blocks;
677 btrfs_i_size_write(inode, src->i_size);
678 BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
679 ret = btrfs_update_inode(trans, root, inode);
680 }
681 btrfs_end_transaction(trans, root);
682 unlock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS);
683 if (ret)
684 vmtruncate(inode, 0);
685 out_unlock:
686 mutex_unlock(&src->i_mutex);
687 mutex_unlock(&inode->i_mutex);
688 vfree(buf);
689 btrfs_free_path(path);
690 out_fput:
691 fput(src_file);
692 return ret;
693 }
694
695 /*
696 * there are many ways the trans_start and trans_end ioctls can lead
697 * to deadlocks. They should only be used by applications that
698 * basically own the machine, and have a very in depth understanding
699 * of all the possible deadlocks and enospc problems.
700 */
701 long btrfs_ioctl_trans_start(struct file *file)
702 {
703 struct inode *inode = fdentry(file)->d_inode;
704 struct btrfs_root *root = BTRFS_I(inode)->root;
705 struct btrfs_trans_handle *trans;
706 int ret = 0;
707
708 if (!capable(CAP_SYS_ADMIN))
709 return -EPERM;
710
711 if (file->private_data) {
712 ret = -EINPROGRESS;
713 goto out;
714 }
715
716 mutex_lock(&root->fs_info->trans_mutex);
717 root->fs_info->open_ioctl_trans++;
718 mutex_unlock(&root->fs_info->trans_mutex);
719
720 trans = btrfs_start_ioctl_transaction(root, 0);
721 if (trans)
722 file->private_data = trans;
723 else
724 ret = -ENOMEM;
725 /*printk(KERN_INFO "btrfs_ioctl_trans_start on %p\n", file);*/
726 out:
727 return ret;
728 }
729
730 /*
731 * there are many ways the trans_start and trans_end ioctls can lead
732 * to deadlocks. They should only be used by applications that
733 * basically own the machine, and have a very in depth understanding
734 * of all the possible deadlocks and enospc problems.
735 */
736 long btrfs_ioctl_trans_end(struct file *file)
737 {
738 struct inode *inode = fdentry(file)->d_inode;
739 struct btrfs_root *root = BTRFS_I(inode)->root;
740 struct btrfs_trans_handle *trans;
741 int ret = 0;
742
743 trans = file->private_data;
744 if (!trans) {
745 ret = -EINVAL;
746 goto out;
747 }
748 btrfs_end_transaction(trans, root);
749 file->private_data = NULL;
750
751 mutex_lock(&root->fs_info->trans_mutex);
752 root->fs_info->open_ioctl_trans--;
753 mutex_unlock(&root->fs_info->trans_mutex);
754
755 out:
756 return ret;
757 }
758
759 long btrfs_ioctl(struct file *file, unsigned int
760 cmd, unsigned long arg)
761 {
762 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
763
764 switch (cmd) {
765 case BTRFS_IOC_SNAP_CREATE:
766 return btrfs_ioctl_snap_create(root, (void __user *)arg);
767 case BTRFS_IOC_DEFRAG:
768 return btrfs_ioctl_defrag(file);
769 case BTRFS_IOC_RESIZE:
770 return btrfs_ioctl_resize(root, (void __user *)arg);
771 case BTRFS_IOC_ADD_DEV:
772 return btrfs_ioctl_add_dev(root, (void __user *)arg);
773 case BTRFS_IOC_RM_DEV:
774 return btrfs_ioctl_rm_dev(root, (void __user *)arg);
775 case BTRFS_IOC_BALANCE:
776 return btrfs_balance(root->fs_info->dev_root);
777 case BTRFS_IOC_CLONE:
778 return btrfs_ioctl_clone(file, arg);
779 case BTRFS_IOC_TRANS_START:
780 return btrfs_ioctl_trans_start(file);
781 case BTRFS_IOC_TRANS_END:
782 return btrfs_ioctl_trans_end(file);
783 case BTRFS_IOC_SYNC:
784 btrfs_start_delalloc_inodes(root);
785 btrfs_sync_fs(file->f_dentry->d_sb, 1);
786 return 0;
787 }
788
789 return -ENOTTY;
790 }
Linux kernel - Deliverables
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