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Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad...
[zen-stable.git] / fs / btrfs / ioctl.c
blob72d461656f606647292657f2367ee438a50d2a40
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/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>
42 #include <linux/slab.h>
43 #include <linux/blkdev.h>
44 #include "compat.h"
45 #include "ctree.h"
46 #include "disk-io.h"
47 #include "transaction.h"
48 #include "btrfs_inode.h"
49 #include "ioctl.h"
50 #include "print-tree.h"
51 #include "volumes.h"
52 #include "locking.h"
53 #include "inode-map.h"
54 #include "backref.h"
55
56 /* Mask out flags that are inappropriate for the given type of inode. */
57 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
58 {
59 if (S_ISDIR(mode))
60 return flags;
61 else if (S_ISREG(mode))
62 return flags & ~FS_DIRSYNC_FL;
63 else
64 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
65 }
66
67 /*
68 * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
69 */
70 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
71 {
72 unsigned int iflags = 0;
73
74 if (flags & BTRFS_INODE_SYNC)
75 iflags |= FS_SYNC_FL;
76 if (flags & BTRFS_INODE_IMMUTABLE)
77 iflags |= FS_IMMUTABLE_FL;
78 if (flags & BTRFS_INODE_APPEND)
79 iflags |= FS_APPEND_FL;
80 if (flags & BTRFS_INODE_NODUMP)
81 iflags |= FS_NODUMP_FL;
82 if (flags & BTRFS_INODE_NOATIME)
83 iflags |= FS_NOATIME_FL;
84 if (flags & BTRFS_INODE_DIRSYNC)
85 iflags |= FS_DIRSYNC_FL;
86 if (flags & BTRFS_INODE_NODATACOW)
87 iflags |= FS_NOCOW_FL;
88
89 if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS))
90 iflags |= FS_COMPR_FL;
91 else if (flags & BTRFS_INODE_NOCOMPRESS)
92 iflags |= FS_NOCOMP_FL;
93
94 return iflags;
95 }
96
97 /*
98 * Update inode->i_flags based on the btrfs internal flags.
99 */
100 void btrfs_update_iflags(struct inode *inode)
101 {
102 struct btrfs_inode *ip = BTRFS_I(inode);
103
104 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
105
106 if (ip->flags & BTRFS_INODE_SYNC)
107 inode->i_flags |= S_SYNC;
108 if (ip->flags & BTRFS_INODE_IMMUTABLE)
109 inode->i_flags |= S_IMMUTABLE;
110 if (ip->flags & BTRFS_INODE_APPEND)
111 inode->i_flags |= S_APPEND;
112 if (ip->flags & BTRFS_INODE_NOATIME)
113 inode->i_flags |= S_NOATIME;
114 if (ip->flags & BTRFS_INODE_DIRSYNC)
115 inode->i_flags |= S_DIRSYNC;
116 }
117
118 /*
119 * Inherit flags from the parent inode.
120 *
121 * Currently only the compression flags and the cow flags are inherited.
122 */
123 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
124 {
125 unsigned int flags;
126
127 if (!dir)
128 return;
129
130 flags = BTRFS_I(dir)->flags;
131
132 if (flags & BTRFS_INODE_NOCOMPRESS) {
133 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
134 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
135 } else if (flags & BTRFS_INODE_COMPRESS) {
136 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
137 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
138 }
139
140 if (flags & BTRFS_INODE_NODATACOW)
141 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
142
143 btrfs_update_iflags(inode);
144 }
145
146 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
147 {
148 struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode);
149 unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
150
151 if (copy_to_user(arg, &flags, sizeof(flags)))
152 return -EFAULT;
153 return 0;
154 }
155
156 static int check_flags(unsigned int flags)
157 {
158 if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
159 FS_NOATIME_FL | FS_NODUMP_FL | \
160 FS_SYNC_FL | FS_DIRSYNC_FL | \
161 FS_NOCOMP_FL | FS_COMPR_FL |
162 FS_NOCOW_FL))
163 return -EOPNOTSUPP;
164
165 if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
166 return -EINVAL;
167
168 return 0;
169 }
170
171 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
172 {
173 struct inode *inode = file->f_path.dentry->d_inode;
174 struct btrfs_inode *ip = BTRFS_I(inode);
175 struct btrfs_root *root = ip->root;
176 struct btrfs_trans_handle *trans;
177 unsigned int flags, oldflags;
178 int ret;
179
180 if (btrfs_root_readonly(root))
181 return -EROFS;
182
183 if (copy_from_user(&flags, arg, sizeof(flags)))
184 return -EFAULT;
185
186 ret = check_flags(flags);
187 if (ret)
188 return ret;
189
190 if (!inode_owner_or_capable(inode))
191 return -EACCES;
192
193 mutex_lock(&inode->i_mutex);
194
195 flags = btrfs_mask_flags(inode->i_mode, flags);
196 oldflags = btrfs_flags_to_ioctl(ip->flags);
197 if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
198 if (!capable(CAP_LINUX_IMMUTABLE)) {
199 ret = -EPERM;
200 goto out_unlock;
201 }
202 }
203
204 ret = mnt_want_write(file->f_path.mnt);
205 if (ret)
206 goto out_unlock;
207
208 if (flags & FS_SYNC_FL)
209 ip->flags |= BTRFS_INODE_SYNC;
210 else
211 ip->flags &= ~BTRFS_INODE_SYNC;
212 if (flags & FS_IMMUTABLE_FL)
213 ip->flags |= BTRFS_INODE_IMMUTABLE;
214 else
215 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
216 if (flags & FS_APPEND_FL)
217 ip->flags |= BTRFS_INODE_APPEND;
218 else
219 ip->flags &= ~BTRFS_INODE_APPEND;
220 if (flags & FS_NODUMP_FL)
221 ip->flags |= BTRFS_INODE_NODUMP;
222 else
223 ip->flags &= ~BTRFS_INODE_NODUMP;
224 if (flags & FS_NOATIME_FL)
225 ip->flags |= BTRFS_INODE_NOATIME;
226 else
227 ip->flags &= ~BTRFS_INODE_NOATIME;
228 if (flags & FS_DIRSYNC_FL)
229 ip->flags |= BTRFS_INODE_DIRSYNC;
230 else
231 ip->flags &= ~BTRFS_INODE_DIRSYNC;
232 if (flags & FS_NOCOW_FL)
233 ip->flags |= BTRFS_INODE_NODATACOW;
234 else
235 ip->flags &= ~BTRFS_INODE_NODATACOW;
236
237 /*
238 * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
239 * flag may be changed automatically if compression code won't make
240 * things smaller.
241 */
242 if (flags & FS_NOCOMP_FL) {
243 ip->flags &= ~BTRFS_INODE_COMPRESS;
244 ip->flags |= BTRFS_INODE_NOCOMPRESS;
245 } else if (flags & FS_COMPR_FL) {
246 ip->flags |= BTRFS_INODE_COMPRESS;
247 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
248 } else {
249 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
250 }
251
252 trans = btrfs_join_transaction(root);
253 BUG_ON(IS_ERR(trans));
254
255 ret = btrfs_update_inode(trans, root, inode);
256 BUG_ON(ret);
257
258 btrfs_update_iflags(inode);
259 inode->i_ctime = CURRENT_TIME;
260 btrfs_end_transaction(trans, root);
261
262 mnt_drop_write(file->f_path.mnt);
263
264 ret = 0;
265 out_unlock:
266 mutex_unlock(&inode->i_mutex);
267 return ret;
268 }
269
270 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
271 {
272 struct inode *inode = file->f_path.dentry->d_inode;
273
274 return put_user(inode->i_generation, arg);
275 }
276
277 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
278 {
279 struct btrfs_root *root = fdentry(file)->d_sb->s_fs_info;
280 struct btrfs_fs_info *fs_info = root->fs_info;
281 struct btrfs_device *device;
282 struct request_queue *q;
283 struct fstrim_range range;
284 u64 minlen = ULLONG_MAX;
285 u64 num_devices = 0;
286 u64 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
287 int ret;
288
289 if (!capable(CAP_SYS_ADMIN))
290 return -EPERM;
291
292 rcu_read_lock();
293 list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
294 dev_list) {
295 if (!device->bdev)
296 continue;
297 q = bdev_get_queue(device->bdev);
298 if (blk_queue_discard(q)) {
299 num_devices++;
300 minlen = min((u64)q->limits.discard_granularity,
301 minlen);
302 }
303 }
304 rcu_read_unlock();
305
306 if (!num_devices)
307 return -EOPNOTSUPP;
308 if (copy_from_user(&range, arg, sizeof(range)))
309 return -EFAULT;
310 if (range.start > total_bytes)
311 return -EINVAL;
312
313 range.len = min(range.len, total_bytes - range.start);
314 range.minlen = max(range.minlen, minlen);
315 ret = btrfs_trim_fs(root, &range);
316 if (ret < 0)
317 return ret;
318
319 if (copy_to_user(arg, &range, sizeof(range)))
320 return -EFAULT;
321
322 return 0;
323 }
324
325 static noinline int create_subvol(struct btrfs_root *root,
326 struct dentry *dentry,
327 char *name, int namelen,
328 u64 *async_transid)
329 {
330 struct btrfs_trans_handle *trans;
331 struct btrfs_key key;
332 struct btrfs_root_item root_item;
333 struct btrfs_inode_item *inode_item;
334 struct extent_buffer *leaf;
335 struct btrfs_root *new_root;
336 struct dentry *parent = dentry->d_parent;
337 struct inode *dir;
338 int ret;
339 int err;
340 u64 objectid;
341 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
342 u64 index = 0;
343
344 ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
345 if (ret)
346 return ret;
347
348 dir = parent->d_inode;
349
350 /*
351 * 1 - inode item
352 * 2 - refs
353 * 1 - root item
354 * 2 - dir items
355 */
356 trans = btrfs_start_transaction(root, 6);
357 if (IS_ERR(trans))
358 return PTR_ERR(trans);
359
360 leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
361 0, objectid, NULL, 0, 0, 0);
362 if (IS_ERR(leaf)) {
363 ret = PTR_ERR(leaf);
364 goto fail;
365 }
366
367 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
368 btrfs_set_header_bytenr(leaf, leaf->start);
369 btrfs_set_header_generation(leaf, trans->transid);
370 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
371 btrfs_set_header_owner(leaf, objectid);
372
373 write_extent_buffer(leaf, root->fs_info->fsid,
374 (unsigned long)btrfs_header_fsid(leaf),
375 BTRFS_FSID_SIZE);
376 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
377 (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
378 BTRFS_UUID_SIZE);
379 btrfs_mark_buffer_dirty(leaf);
380
381 inode_item = &root_item.inode;
382 memset(inode_item, 0, sizeof(*inode_item));
383 inode_item->generation = cpu_to_le64(1);
384 inode_item->size = cpu_to_le64(3);
385 inode_item->nlink = cpu_to_le32(1);
386 inode_item->nbytes = cpu_to_le64(root->leafsize);
387 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
388
389 root_item.flags = 0;
390 root_item.byte_limit = 0;
391 inode_item->flags = cpu_to_le64(BTRFS_INODE_ROOT_ITEM_INIT);
392
393 btrfs_set_root_bytenr(&root_item, leaf->start);
394 btrfs_set_root_generation(&root_item, trans->transid);
395 btrfs_set_root_level(&root_item, 0);
396 btrfs_set_root_refs(&root_item, 1);
397 btrfs_set_root_used(&root_item, leaf->len);
398 btrfs_set_root_last_snapshot(&root_item, 0);
399
400 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
401 root_item.drop_level = 0;
402
403 btrfs_tree_unlock(leaf);
404 free_extent_buffer(leaf);
405 leaf = NULL;
406
407 btrfs_set_root_dirid(&root_item, new_dirid);
408
409 key.objectid = objectid;
410 key.offset = 0;
411 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
412 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
413 &root_item);
414 if (ret)
415 goto fail;
416
417 key.offset = (u64)-1;
418 new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
419 BUG_ON(IS_ERR(new_root));
420
421 btrfs_record_root_in_trans(trans, new_root);
422
423 ret = btrfs_create_subvol_root(trans, new_root, new_dirid);
424 /*
425 * insert the directory item
426 */
427 ret = btrfs_set_inode_index(dir, &index);
428 BUG_ON(ret);
429
430 ret = btrfs_insert_dir_item(trans, root,
431 name, namelen, dir, &key,
432 BTRFS_FT_DIR, index);
433 if (ret)
434 goto fail;
435
436 btrfs_i_size_write(dir, dir->i_size + namelen * 2);
437 ret = btrfs_update_inode(trans, root, dir);
438 BUG_ON(ret);
439
440 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
441 objectid, root->root_key.objectid,
442 btrfs_ino(dir), index, name, namelen);
443
444 BUG_ON(ret);
445
446 d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
447 fail:
448 if (async_transid) {
449 *async_transid = trans->transid;
450 err = btrfs_commit_transaction_async(trans, root, 1);
451 } else {
452 err = btrfs_commit_transaction(trans, root);
453 }
454 if (err && !ret)
455 ret = err;
456 return ret;
457 }
458
459 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
460 char *name, int namelen, u64 *async_transid,
461 bool readonly)
462 {
463 struct inode *inode;
464 struct btrfs_pending_snapshot *pending_snapshot;
465 struct btrfs_trans_handle *trans;
466 int ret;
467
468 if (!root->ref_cows)
469 return -EINVAL;
470
471 pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
472 if (!pending_snapshot)
473 return -ENOMEM;
474
475 btrfs_init_block_rsv(&pending_snapshot->block_rsv);
476 pending_snapshot->dentry = dentry;
477 pending_snapshot->root = root;
478 pending_snapshot->readonly = readonly;
479
480 trans = btrfs_start_transaction(root->fs_info->extent_root, 5);
481 if (IS_ERR(trans)) {
482 ret = PTR_ERR(trans);
483 goto fail;
484 }
485
486 ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
487 BUG_ON(ret);
488
489 spin_lock(&root->fs_info->trans_lock);
490 list_add(&pending_snapshot->list,
491 &trans->transaction->pending_snapshots);
492 spin_unlock(&root->fs_info->trans_lock);
493 if (async_transid) {
494 *async_transid = trans->transid;
495 ret = btrfs_commit_transaction_async(trans,
496 root->fs_info->extent_root, 1);
497 } else {
498 ret = btrfs_commit_transaction(trans,
499 root->fs_info->extent_root);
500 }
501 BUG_ON(ret);
502
503 ret = pending_snapshot->error;
504 if (ret)
505 goto fail;
506
507 ret = btrfs_orphan_cleanup(pending_snapshot->snap);
508 if (ret)
509 goto fail;
510
511 inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
512 if (IS_ERR(inode)) {
513 ret = PTR_ERR(inode);
514 goto fail;
515 }
516 BUG_ON(!inode);
517 d_instantiate(dentry, inode);
518 ret = 0;
519 fail:
520 kfree(pending_snapshot);
521 return ret;
522 }
523
524 /* copy of check_sticky in fs/namei.c()
525 * It's inline, so penalty for filesystems that don't use sticky bit is
526 * minimal.
527 */
528 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode)
529 {
530 uid_t fsuid = current_fsuid();
531
532 if (!(dir->i_mode & S_ISVTX))
533 return 0;
534 if (inode->i_uid == fsuid)
535 return 0;
536 if (dir->i_uid == fsuid)
537 return 0;
538 return !capable(CAP_FOWNER);
539 }
540
541 /* copy of may_delete in fs/namei.c()
542 * Check whether we can remove a link victim from directory dir, check
543 * whether the type of victim is right.
544 * 1. We can't do it if dir is read-only (done in permission())
545 * 2. We should have write and exec permissions on dir
546 * 3. We can't remove anything from append-only dir
547 * 4. We can't do anything with immutable dir (done in permission())
548 * 5. If the sticky bit on dir is set we should either
549 * a. be owner of dir, or
550 * b. be owner of victim, or
551 * c. have CAP_FOWNER capability
552 * 6. If the victim is append-only or immutable we can't do antyhing with
553 * links pointing to it.
554 * 7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
555 * 8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
556 * 9. We can't remove a root or mountpoint.
557 * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
558 * nfs_async_unlink().
559 */
560
561 static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir)
562 {
563 int error;
564
565 if (!victim->d_inode)
566 return -ENOENT;
567
568 BUG_ON(victim->d_parent->d_inode != dir);
569 audit_inode_child(victim, dir);
570
571 error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
572 if (error)
573 return error;
574 if (IS_APPEND(dir))
575 return -EPERM;
576 if (btrfs_check_sticky(dir, victim->d_inode)||
577 IS_APPEND(victim->d_inode)||
578 IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
579 return -EPERM;
580 if (isdir) {
581 if (!S_ISDIR(victim->d_inode->i_mode))
582 return -ENOTDIR;
583 if (IS_ROOT(victim))
584 return -EBUSY;
585 } else if (S_ISDIR(victim->d_inode->i_mode))
586 return -EISDIR;
587 if (IS_DEADDIR(dir))
588 return -ENOENT;
589 if (victim->d_flags & DCACHE_NFSFS_RENAMED)
590 return -EBUSY;
591 return 0;
592 }
593
594 /* copy of may_create in fs/namei.c() */
595 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
596 {
597 if (child->d_inode)
598 return -EEXIST;
599 if (IS_DEADDIR(dir))
600 return -ENOENT;
601 return inode_permission(dir, MAY_WRITE | MAY_EXEC);
602 }
603
604 /*
605 * Create a new subvolume below @parent. This is largely modeled after
606 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
607 * inside this filesystem so it's quite a bit simpler.
608 */
609 static noinline int btrfs_mksubvol(struct path *parent,
610 char *name, int namelen,
611 struct btrfs_root *snap_src,
612 u64 *async_transid, bool readonly)
613 {
614 struct inode *dir = parent->dentry->d_inode;
615 struct dentry *dentry;
616 int error;
617
618 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
619
620 dentry = lookup_one_len(name, parent->dentry, namelen);
621 error = PTR_ERR(dentry);
622 if (IS_ERR(dentry))
623 goto out_unlock;
624
625 error = -EEXIST;
626 if (dentry->d_inode)
627 goto out_dput;
628
629 error = mnt_want_write(parent->mnt);
630 if (error)
631 goto out_dput;
632
633 error = btrfs_may_create(dir, dentry);
634 if (error)
635 goto out_drop_write;
636
637 down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
638
639 if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
640 goto out_up_read;
641
642 if (snap_src) {
643 error = create_snapshot(snap_src, dentry,
644 name, namelen, async_transid, readonly);
645 } else {
646 error = create_subvol(BTRFS_I(dir)->root, dentry,
647 name, namelen, async_transid);
648 }
649 if (!error)
650 fsnotify_mkdir(dir, dentry);
651 out_up_read:
652 up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
653 out_drop_write:
654 mnt_drop_write(parent->mnt);
655 out_dput:
656 dput(dentry);
657 out_unlock:
658 mutex_unlock(&dir->i_mutex);
659 return error;
660 }
661
662 /*
663 * When we're defragging a range, we don't want to kick it off again
664 * if it is really just waiting for delalloc to send it down.
665 * If we find a nice big extent or delalloc range for the bytes in the
666 * file you want to defrag, we return 0 to let you know to skip this
667 * part of the file
668 */
669 static int check_defrag_in_cache(struct inode *inode, u64 offset, int thresh)
670 {
671 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
672 struct extent_map *em = NULL;
673 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
674 u64 end;
675
676 read_lock(&em_tree->lock);
677 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
678 read_unlock(&em_tree->lock);
679
680 if (em) {
681 end = extent_map_end(em);
682 free_extent_map(em);
683 if (end - offset > thresh)
684 return 0;
685 }
686 /* if we already have a nice delalloc here, just stop */
687 thresh /= 2;
688 end = count_range_bits(io_tree, &offset, offset + thresh,
689 thresh, EXTENT_DELALLOC, 1);
690 if (end >= thresh)
691 return 0;
692 return 1;
693 }
694
695 /*
696 * helper function to walk through a file and find extents
697 * newer than a specific transid, and smaller than thresh.
698 *
699 * This is used by the defragging code to find new and small
700 * extents
701 */
702 static int find_new_extents(struct btrfs_root *root,
703 struct inode *inode, u64 newer_than,
704 u64 *off, int thresh)
705 {
706 struct btrfs_path *path;
707 struct btrfs_key min_key;
708 struct btrfs_key max_key;
709 struct extent_buffer *leaf;
710 struct btrfs_file_extent_item *extent;
711 int type;
712 int ret;
713 u64 ino = btrfs_ino(inode);
714
715 path = btrfs_alloc_path();
716 if (!path)
717 return -ENOMEM;
718
719 min_key.objectid = ino;
720 min_key.type = BTRFS_EXTENT_DATA_KEY;
721 min_key.offset = *off;
722
723 max_key.objectid = ino;
724 max_key.type = (u8)-1;
725 max_key.offset = (u64)-1;
726
727 path->keep_locks = 1;
728
729 while(1) {
730 ret = btrfs_search_forward(root, &min_key, &max_key,
731 path, 0, newer_than);
732 if (ret != 0)
733 goto none;
734 if (min_key.objectid != ino)
735 goto none;
736 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
737 goto none;
738
739 leaf = path->nodes[0];
740 extent = btrfs_item_ptr(leaf, path->slots[0],
741 struct btrfs_file_extent_item);
742
743 type = btrfs_file_extent_type(leaf, extent);
744 if (type == BTRFS_FILE_EXTENT_REG &&
745 btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
746 check_defrag_in_cache(inode, min_key.offset, thresh)) {
747 *off = min_key.offset;
748 btrfs_free_path(path);
749 return 0;
750 }
751
752 if (min_key.offset == (u64)-1)
753 goto none;
754
755 min_key.offset++;
756 btrfs_release_path(path);
757 }
758 none:
759 btrfs_free_path(path);
760 return -ENOENT;
761 }
762
763 static int should_defrag_range(struct inode *inode, u64 start, u64 len,
764 int thresh, u64 *last_len, u64 *skip,
765 u64 *defrag_end)
766 {
767 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
768 struct extent_map *em = NULL;
769 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
770 int ret = 1;
771
772 /*
773 * make sure that once we start defragging an extent, we keep on
774 * defragging it
775 */
776 if (start < *defrag_end)
777 return 1;
778
779 *skip = 0;
780
781 /*
782 * hopefully we have this extent in the tree already, try without
783 * the full extent lock
784 */
785 read_lock(&em_tree->lock);
786 em = lookup_extent_mapping(em_tree, start, len);
787 read_unlock(&em_tree->lock);
788
789 if (!em) {
790 /* get the big lock and read metadata off disk */
791 lock_extent(io_tree, start, start + len - 1, GFP_NOFS);
792 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
793 unlock_extent(io_tree, start, start + len - 1, GFP_NOFS);
794
795 if (IS_ERR(em))
796 return 0;
797 }
798
799 /* this will cover holes, and inline extents */
800 if (em->block_start >= EXTENT_MAP_LAST_BYTE)
801 ret = 0;
802
803 /*
804 * we hit a real extent, if it is big don't bother defragging it again
805 */
806 if ((*last_len == 0 || *last_len >= thresh) && em->len >= thresh)
807 ret = 0;
808
809 /*
810 * last_len ends up being a counter of how many bytes we've defragged.
811 * every time we choose not to defrag an extent, we reset *last_len
812 * so that the next tiny extent will force a defrag.
813 *
814 * The end result of this is that tiny extents before a single big
815 * extent will force at least part of that big extent to be defragged.
816 */
817 if (ret) {
818 *defrag_end = extent_map_end(em);
819 } else {
820 *last_len = 0;
821 *skip = extent_map_end(em);
822 *defrag_end = 0;
823 }
824
825 free_extent_map(em);
826 return ret;
827 }
828
829 /*
830 * it doesn't do much good to defrag one or two pages
831 * at a time. This pulls in a nice chunk of pages
832 * to COW and defrag.
833 *
834 * It also makes sure the delalloc code has enough
835 * dirty data to avoid making new small extents as part
836 * of the defrag
837 *
838 * It's a good idea to start RA on this range
839 * before calling this.
840 */
841 static int cluster_pages_for_defrag(struct inode *inode,
842 struct page **pages,
843 unsigned long start_index,
844 int num_pages)
845 {
846 unsigned long file_end;
847 u64 isize = i_size_read(inode);
848 u64 page_start;
849 u64 page_end;
850 int ret;
851 int i;
852 int i_done;
853 struct btrfs_ordered_extent *ordered;
854 struct extent_state *cached_state = NULL;
855 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
856
857 if (isize == 0)
858 return 0;
859 file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
860
861 ret = btrfs_delalloc_reserve_space(inode,
862 num_pages << PAGE_CACHE_SHIFT);
863 if (ret)
864 return ret;
865 again:
866 ret = 0;
867 i_done = 0;
868
869 /* step one, lock all the pages */
870 for (i = 0; i < num_pages; i++) {
871 struct page *page;
872 page = find_or_create_page(inode->i_mapping,
873 start_index + i, mask);
874 if (!page)
875 break;
876
877 if (!PageUptodate(page)) {
878 btrfs_readpage(NULL, page);
879 lock_page(page);
880 if (!PageUptodate(page)) {
881 unlock_page(page);
882 page_cache_release(page);
883 ret = -EIO;
884 break;
885 }
886 }
887 isize = i_size_read(inode);
888 file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
889 if (!isize || page->index > file_end ||
890 page->mapping != inode->i_mapping) {
891 /* whoops, we blew past eof, skip this page */
892 unlock_page(page);
893 page_cache_release(page);
894 break;
895 }
896 pages[i] = page;
897 i_done++;
898 }
899 if (!i_done || ret)
900 goto out;
901
902 if (!(inode->i_sb->s_flags & MS_ACTIVE))
903 goto out;
904
905 /*
906 * so now we have a nice long stream of locked
907 * and up to date pages, lets wait on them
908 */
909 for (i = 0; i < i_done; i++)
910 wait_on_page_writeback(pages[i]);
911
912 page_start = page_offset(pages[0]);
913 page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
914
915 lock_extent_bits(&BTRFS_I(inode)->io_tree,
916 page_start, page_end - 1, 0, &cached_state,
917 GFP_NOFS);
918 ordered = btrfs_lookup_first_ordered_extent(inode, page_end - 1);
919 if (ordered &&
920 ordered->file_offset + ordered->len > page_start &&
921 ordered->file_offset < page_end) {
922 btrfs_put_ordered_extent(ordered);
923 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
924 page_start, page_end - 1,
925 &cached_state, GFP_NOFS);
926 for (i = 0; i < i_done; i++) {
927 unlock_page(pages[i]);
928 page_cache_release(pages[i]);
929 }
930 btrfs_wait_ordered_range(inode, page_start,
931 page_end - page_start);
932 goto again;
933 }
934 if (ordered)
935 btrfs_put_ordered_extent(ordered);
936
937 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
938 page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
939 EXTENT_DO_ACCOUNTING, 0, 0, &cached_state,
940 GFP_NOFS);
941
942 if (i_done != num_pages) {
943 spin_lock(&BTRFS_I(inode)->lock);
944 BTRFS_I(inode)->outstanding_extents++;
945 spin_unlock(&BTRFS_I(inode)->lock);
946 btrfs_delalloc_release_space(inode,
947 (num_pages - i_done) << PAGE_CACHE_SHIFT);
948 }
949
950
951 btrfs_set_extent_delalloc(inode, page_start, page_end - 1,
952 &cached_state);
953
954 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
955 page_start, page_end - 1, &cached_state,
956 GFP_NOFS);
957
958 for (i = 0; i < i_done; i++) {
959 clear_page_dirty_for_io(pages[i]);
960 ClearPageChecked(pages[i]);
961 set_page_extent_mapped(pages[i]);
962 set_page_dirty(pages[i]);
963 unlock_page(pages[i]);
964 page_cache_release(pages[i]);
965 }
966 return i_done;
967 out:
968 for (i = 0; i < i_done; i++) {
969 unlock_page(pages[i]);
970 page_cache_release(pages[i]);
971 }
972 btrfs_delalloc_release_space(inode, num_pages << PAGE_CACHE_SHIFT);
973 return ret;
974
975 }
976
977 int btrfs_defrag_file(struct inode *inode, struct file *file,
978 struct btrfs_ioctl_defrag_range_args *range,
979 u64 newer_than, unsigned long max_to_defrag)
980 {
981 struct btrfs_root *root = BTRFS_I(inode)->root;
982 struct btrfs_super_block *disk_super;
983 struct file_ra_state *ra = NULL;
984 unsigned long last_index;
985 u64 isize = i_size_read(inode);
986 u64 features;
987 u64 last_len = 0;
988 u64 skip = 0;
989 u64 defrag_end = 0;
990 u64 newer_off = range->start;
991 unsigned long i;
992 unsigned long ra_index = 0;
993 int ret;
994 int defrag_count = 0;
995 int compress_type = BTRFS_COMPRESS_ZLIB;
996 int extent_thresh = range->extent_thresh;
997 int max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT;
998 int cluster = max_cluster;
999 u64 new_align = ~((u64)128 * 1024 - 1);
1000 struct page **pages = NULL;
1001
1002 if (extent_thresh == 0)
1003 extent_thresh = 256 * 1024;
1004
1005 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1006 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1007 return -EINVAL;
1008 if (range->compress_type)
1009 compress_type = range->compress_type;
1010 }
1011
1012 if (isize == 0)
1013 return 0;
1014
1015 /*
1016 * if we were not given a file, allocate a readahead
1017 * context
1018 */
1019 if (!file) {
1020 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1021 if (!ra)
1022 return -ENOMEM;
1023 file_ra_state_init(ra, inode->i_mapping);
1024 } else {
1025 ra = &file->f_ra;
1026 }
1027
1028 pages = kmalloc(sizeof(struct page *) * max_cluster,
1029 GFP_NOFS);
1030 if (!pages) {
1031 ret = -ENOMEM;
1032 goto out_ra;
1033 }
1034
1035 /* find the last page to defrag */
1036 if (range->start + range->len > range->start) {
1037 last_index = min_t(u64, isize - 1,
1038 range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
1039 } else {
1040 last_index = (isize - 1) >> PAGE_CACHE_SHIFT;
1041 }
1042
1043 if (newer_than) {
1044 ret = find_new_extents(root, inode, newer_than,
1045 &newer_off, 64 * 1024);
1046 if (!ret) {
1047 range->start = newer_off;
1048 /*
1049 * we always align our defrag to help keep
1050 * the extents in the file evenly spaced
1051 */
1052 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1053 } else
1054 goto out_ra;
1055 } else {
1056 i = range->start >> PAGE_CACHE_SHIFT;
1057 }
1058 if (!max_to_defrag)
1059 max_to_defrag = last_index;
1060
1061 /*
1062 * make writeback starts from i, so the defrag range can be
1063 * written sequentially.
1064 */
1065 if (i < inode->i_mapping->writeback_index)
1066 inode->i_mapping->writeback_index = i;
1067
1068 while (i <= last_index && defrag_count < max_to_defrag &&
1069 (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1070 PAGE_CACHE_SHIFT)) {
1071 /*
1072 * make sure we stop running if someone unmounts
1073 * the FS
1074 */
1075 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1076 break;
1077
1078 if (!newer_than &&
1079 !should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
1080 PAGE_CACHE_SIZE,
1081 extent_thresh,
1082 &last_len, &skip,
1083 &defrag_end)) {
1084 unsigned long next;
1085 /*
1086 * the should_defrag function tells us how much to skip
1087 * bump our counter by the suggested amount
1088 */
1089 next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1090 i = max(i + 1, next);
1091 continue;
1092 }
1093
1094 if (!newer_than) {
1095 cluster = (PAGE_CACHE_ALIGN(defrag_end) >>
1096 PAGE_CACHE_SHIFT) - i;
1097 cluster = min(cluster, max_cluster);
1098 } else {
1099 cluster = max_cluster;
1100 }
1101
1102 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1103 BTRFS_I(inode)->force_compress = compress_type;
1104
1105 if (i + cluster > ra_index) {
1106 ra_index = max(i, ra_index);
1107 btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1108 cluster);
1109 ra_index += max_cluster;
1110 }
1111
1112 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1113 if (ret < 0)
1114 goto out_ra;
1115
1116 defrag_count += ret;
1117 balance_dirty_pages_ratelimited_nr(inode->i_mapping, ret);
1118
1119 if (newer_than) {
1120 if (newer_off == (u64)-1)
1121 break;
1122
1123 newer_off = max(newer_off + 1,
1124 (u64)i << PAGE_CACHE_SHIFT);
1125
1126 ret = find_new_extents(root, inode,
1127 newer_than, &newer_off,
1128 64 * 1024);
1129 if (!ret) {
1130 range->start = newer_off;
1131 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1132 } else {
1133 break;
1134 }
1135 } else {
1136 if (ret > 0) {
1137 i += ret;
1138 last_len += ret << PAGE_CACHE_SHIFT;
1139 } else {
1140 i++;
1141 last_len = 0;
1142 }
1143 }
1144 }
1145
1146 if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
1147 filemap_flush(inode->i_mapping);
1148
1149 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1150 /* the filemap_flush will queue IO into the worker threads, but
1151 * we have to make sure the IO is actually started and that
1152 * ordered extents get created before we return
1153 */
1154 atomic_inc(&root->fs_info->async_submit_draining);
1155 while (atomic_read(&root->fs_info->nr_async_submits) ||
1156 atomic_read(&root->fs_info->async_delalloc_pages)) {
1157 wait_event(root->fs_info->async_submit_wait,
1158 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1159 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1160 }
1161 atomic_dec(&root->fs_info->async_submit_draining);
1162
1163 mutex_lock(&inode->i_mutex);
1164 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1165 mutex_unlock(&inode->i_mutex);
1166 }
1167
1168 disk_super = root->fs_info->super_copy;
1169 features = btrfs_super_incompat_flags(disk_super);
1170 if (range->compress_type == BTRFS_COMPRESS_LZO) {
1171 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
1172 btrfs_set_super_incompat_flags(disk_super, features);
1173 }
1174
1175 ret = defrag_count;
1176
1177 out_ra:
1178 if (!file)
1179 kfree(ra);
1180 kfree(pages);
1181 return ret;
1182 }
1183
1184 static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
1185 void __user *arg)
1186 {
1187 u64 new_size;
1188 u64 old_size;
1189 u64 devid = 1;
1190 struct btrfs_ioctl_vol_args *vol_args;
1191 struct btrfs_trans_handle *trans;
1192 struct btrfs_device *device = NULL;
1193 char *sizestr;
1194 char *devstr = NULL;
1195 int ret = 0;
1196 int mod = 0;
1197
1198 if (root->fs_info->sb->s_flags & MS_RDONLY)
1199 return -EROFS;
1200
1201 if (!capable(CAP_SYS_ADMIN))
1202 return -EPERM;
1203
1204 vol_args = memdup_user(arg, sizeof(*vol_args));
1205 if (IS_ERR(vol_args))
1206 return PTR_ERR(vol_args);
1207
1208 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1209
1210 mutex_lock(&root->fs_info->volume_mutex);
1211 sizestr = vol_args->name;
1212 devstr = strchr(sizestr, ':');
1213 if (devstr) {
1214 char *end;
1215 sizestr = devstr + 1;
1216 *devstr = '\0';
1217 devstr = vol_args->name;
1218 devid = simple_strtoull(devstr, &end, 10);
1219 printk(KERN_INFO "btrfs: resizing devid %llu\n",
1220 (unsigned long long)devid);
1221 }
1222 device = btrfs_find_device(root, devid, NULL, NULL);
1223 if (!device) {
1224 printk(KERN_INFO "btrfs: resizer unable to find device %llu\n",
1225 (unsigned long long)devid);
1226 ret = -EINVAL;
1227 goto out_unlock;
1228 }
1229 if (!strcmp(sizestr, "max"))
1230 new_size = device->bdev->bd_inode->i_size;
1231 else {
1232 if (sizestr[0] == '-') {
1233 mod = -1;
1234 sizestr++;
1235 } else if (sizestr[0] == '+') {
1236 mod = 1;
1237 sizestr++;
1238 }
1239 new_size = memparse(sizestr, NULL);
1240 if (new_size == 0) {
1241 ret = -EINVAL;
1242 goto out_unlock;
1243 }
1244 }
1245
1246 old_size = device->total_bytes;
1247
1248 if (mod < 0) {
1249 if (new_size > old_size) {
1250 ret = -EINVAL;
1251 goto out_unlock;
1252 }
1253 new_size = old_size - new_size;
1254 } else if (mod > 0) {
1255 new_size = old_size + new_size;
1256 }
1257
1258 if (new_size < 256 * 1024 * 1024) {
1259 ret = -EINVAL;
1260 goto out_unlock;
1261 }
1262 if (new_size > device->bdev->bd_inode->i_size) {
1263 ret = -EFBIG;
1264 goto out_unlock;
1265 }
1266
1267 do_div(new_size, root->sectorsize);
1268 new_size *= root->sectorsize;
1269
1270 printk(KERN_INFO "btrfs: new size for %s is %llu\n",
1271 device->name, (unsigned long long)new_size);
1272
1273 if (new_size > old_size) {
1274 trans = btrfs_start_transaction(root, 0);
1275 if (IS_ERR(trans)) {
1276 ret = PTR_ERR(trans);
1277 goto out_unlock;
1278 }
1279 ret = btrfs_grow_device(trans, device, new_size);
1280 btrfs_commit_transaction(trans, root);
1281 } else if (new_size < old_size) {
1282 ret = btrfs_shrink_device(device, new_size);
1283 }
1284
1285 out_unlock:
1286 mutex_unlock(&root->fs_info->volume_mutex);
1287 kfree(vol_args);
1288 return ret;
1289 }
1290
1291 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1292 char *name,
1293 unsigned long fd,
1294 int subvol,
1295 u64 *transid,
1296 bool readonly)
1297 {
1298 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
1299 struct file *src_file;
1300 int namelen;
1301 int ret = 0;
1302
1303 if (root->fs_info->sb->s_flags & MS_RDONLY)
1304 return -EROFS;
1305
1306 namelen = strlen(name);
1307 if (strchr(name, '/')) {
1308 ret = -EINVAL;
1309 goto out;
1310 }
1311
1312 if (subvol) {
1313 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1314 NULL, transid, readonly);
1315 } else {
1316 struct inode *src_inode;
1317 src_file = fget(fd);
1318 if (!src_file) {
1319 ret = -EINVAL;
1320 goto out;
1321 }
1322
1323 src_inode = src_file->f_path.dentry->d_inode;
1324 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
1325 printk(KERN_INFO "btrfs: Snapshot src from "
1326 "another FS\n");
1327 ret = -EINVAL;
1328 fput(src_file);
1329 goto out;
1330 }
1331 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1332 BTRFS_I(src_inode)->root,
1333 transid, readonly);
1334 fput(src_file);
1335 }
1336 out:
1337 return ret;
1338 }
1339
1340 static noinline int btrfs_ioctl_snap_create(struct file *file,
1341 void __user *arg, int subvol)
1342 {
1343 struct btrfs_ioctl_vol_args *vol_args;
1344 int ret;
1345
1346 vol_args = memdup_user(arg, sizeof(*vol_args));
1347 if (IS_ERR(vol_args))
1348 return PTR_ERR(vol_args);
1349 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1350
1351 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1352 vol_args->fd, subvol,
1353 NULL, false);
1354
1355 kfree(vol_args);
1356 return ret;
1357 }
1358
1359 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1360 void __user *arg, int subvol)
1361 {
1362 struct btrfs_ioctl_vol_args_v2 *vol_args;
1363 int ret;
1364 u64 transid = 0;
1365 u64 *ptr = NULL;
1366 bool readonly = false;
1367
1368 vol_args = memdup_user(arg, sizeof(*vol_args));
1369 if (IS_ERR(vol_args))
1370 return PTR_ERR(vol_args);
1371 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1372
1373 if (vol_args->flags &
1374 ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY)) {
1375 ret = -EOPNOTSUPP;
1376 goto out;
1377 }
1378
1379 if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1380 ptr = &transid;
1381 if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1382 readonly = true;
1383
1384 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1385 vol_args->fd, subvol,
1386 ptr, readonly);
1387
1388 if (ret == 0 && ptr &&
1389 copy_to_user(arg +
1390 offsetof(struct btrfs_ioctl_vol_args_v2,
1391 transid), ptr, sizeof(*ptr)))
1392 ret = -EFAULT;
1393 out:
1394 kfree(vol_args);
1395 return ret;
1396 }
1397
1398 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1399 void __user *arg)
1400 {
1401 struct inode *inode = fdentry(file)->d_inode;
1402 struct btrfs_root *root = BTRFS_I(inode)->root;
1403 int ret = 0;
1404 u64 flags = 0;
1405
1406 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1407 return -EINVAL;
1408
1409 down_read(&root->fs_info->subvol_sem);
1410 if (btrfs_root_readonly(root))
1411 flags |= BTRFS_SUBVOL_RDONLY;
1412 up_read(&root->fs_info->subvol_sem);
1413
1414 if (copy_to_user(arg, &flags, sizeof(flags)))
1415 ret = -EFAULT;
1416
1417 return ret;
1418 }
1419
1420 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1421 void __user *arg)
1422 {
1423 struct inode *inode = fdentry(file)->d_inode;
1424 struct btrfs_root *root = BTRFS_I(inode)->root;
1425 struct btrfs_trans_handle *trans;
1426 u64 root_flags;
1427 u64 flags;
1428 int ret = 0;
1429
1430 if (root->fs_info->sb->s_flags & MS_RDONLY)
1431 return -EROFS;
1432
1433 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1434 return -EINVAL;
1435
1436 if (copy_from_user(&flags, arg, sizeof(flags)))
1437 return -EFAULT;
1438
1439 if (flags & BTRFS_SUBVOL_CREATE_ASYNC)
1440 return -EINVAL;
1441
1442 if (flags & ~BTRFS_SUBVOL_RDONLY)
1443 return -EOPNOTSUPP;
1444
1445 if (!inode_owner_or_capable(inode))
1446 return -EACCES;
1447
1448 down_write(&root->fs_info->subvol_sem);
1449
1450 /* nothing to do */
1451 if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1452 goto out;
1453
1454 root_flags = btrfs_root_flags(&root->root_item);
1455 if (flags & BTRFS_SUBVOL_RDONLY)
1456 btrfs_set_root_flags(&root->root_item,
1457 root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1458 else
1459 btrfs_set_root_flags(&root->root_item,
1460 root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1461
1462 trans = btrfs_start_transaction(root, 1);
1463 if (IS_ERR(trans)) {
1464 ret = PTR_ERR(trans);
1465 goto out_reset;
1466 }
1467
1468 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1469 &root->root_key, &root->root_item);
1470
1471 btrfs_commit_transaction(trans, root);
1472 out_reset:
1473 if (ret)
1474 btrfs_set_root_flags(&root->root_item, root_flags);
1475 out:
1476 up_write(&root->fs_info->subvol_sem);
1477 return ret;
1478 }
1479
1480 /*
1481 * helper to check if the subvolume references other subvolumes
1482 */
1483 static noinline int may_destroy_subvol(struct btrfs_root *root)
1484 {
1485 struct btrfs_path *path;
1486 struct btrfs_key key;
1487 int ret;
1488
1489 path = btrfs_alloc_path();
1490 if (!path)
1491 return -ENOMEM;
1492
1493 key.objectid = root->root_key.objectid;
1494 key.type = BTRFS_ROOT_REF_KEY;
1495 key.offset = (u64)-1;
1496
1497 ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1498 &key, path, 0, 0);
1499 if (ret < 0)
1500 goto out;
1501 BUG_ON(ret == 0);
1502
1503 ret = 0;
1504 if (path->slots[0] > 0) {
1505 path->slots[0]--;
1506 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1507 if (key.objectid == root->root_key.objectid &&
1508 key.type == BTRFS_ROOT_REF_KEY)
1509 ret = -ENOTEMPTY;
1510 }
1511 out:
1512 btrfs_free_path(path);
1513 return ret;
1514 }
1515
1516 static noinline int key_in_sk(struct btrfs_key *key,
1517 struct btrfs_ioctl_search_key *sk)
1518 {
1519 struct btrfs_key test;
1520 int ret;
1521
1522 test.objectid = sk->min_objectid;
1523 test.type = sk->min_type;
1524 test.offset = sk->min_offset;
1525
1526 ret = btrfs_comp_cpu_keys(key, &test);
1527 if (ret < 0)
1528 return 0;
1529
1530 test.objectid = sk->max_objectid;
1531 test.type = sk->max_type;
1532 test.offset = sk->max_offset;
1533
1534 ret = btrfs_comp_cpu_keys(key, &test);
1535 if (ret > 0)
1536 return 0;
1537 return 1;
1538 }
1539
1540 static noinline int copy_to_sk(struct btrfs_root *root,
1541 struct btrfs_path *path,
1542 struct btrfs_key *key,
1543 struct btrfs_ioctl_search_key *sk,
1544 char *buf,
1545 unsigned long *sk_offset,
1546 int *num_found)
1547 {
1548 u64 found_transid;
1549 struct extent_buffer *leaf;
1550 struct btrfs_ioctl_search_header sh;
1551 unsigned long item_off;
1552 unsigned long item_len;
1553 int nritems;
1554 int i;
1555 int slot;
1556 int ret = 0;
1557
1558 leaf = path->nodes[0];
1559 slot = path->slots[0];
1560 nritems = btrfs_header_nritems(leaf);
1561
1562 if (btrfs_header_generation(leaf) > sk->max_transid) {
1563 i = nritems;
1564 goto advance_key;
1565 }
1566 found_transid = btrfs_header_generation(leaf);
1567
1568 for (i = slot; i < nritems; i++) {
1569 item_off = btrfs_item_ptr_offset(leaf, i);
1570 item_len = btrfs_item_size_nr(leaf, i);
1571
1572 if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1573 item_len = 0;
1574
1575 if (sizeof(sh) + item_len + *sk_offset >
1576 BTRFS_SEARCH_ARGS_BUFSIZE) {
1577 ret = 1;
1578 goto overflow;
1579 }
1580
1581 btrfs_item_key_to_cpu(leaf, key, i);
1582 if (!key_in_sk(key, sk))
1583 continue;
1584
1585 sh.objectid = key->objectid;
1586 sh.offset = key->offset;
1587 sh.type = key->type;
1588 sh.len = item_len;
1589 sh.transid = found_transid;
1590
1591 /* copy search result header */
1592 memcpy(buf + *sk_offset, &sh, sizeof(sh));
1593 *sk_offset += sizeof(sh);
1594
1595 if (item_len) {
1596 char *p = buf + *sk_offset;
1597 /* copy the item */
1598 read_extent_buffer(leaf, p,
1599 item_off, item_len);
1600 *sk_offset += item_len;
1601 }
1602 (*num_found)++;
1603
1604 if (*num_found >= sk->nr_items)
1605 break;
1606 }
1607 advance_key:
1608 ret = 0;
1609 if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1610 key->offset++;
1611 else if (key->type < (u8)-1 && key->type < sk->max_type) {
1612 key->offset = 0;
1613 key->type++;
1614 } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1615 key->offset = 0;
1616 key->type = 0;
1617 key->objectid++;
1618 } else
1619 ret = 1;
1620 overflow:
1621 return ret;
1622 }
1623
1624 static noinline int search_ioctl(struct inode *inode,
1625 struct btrfs_ioctl_search_args *args)
1626 {
1627 struct btrfs_root *root;
1628 struct btrfs_key key;
1629 struct btrfs_key max_key;
1630 struct btrfs_path *path;
1631 struct btrfs_ioctl_search_key *sk = &args->key;
1632 struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1633 int ret;
1634 int num_found = 0;
1635 unsigned long sk_offset = 0;
1636
1637 path = btrfs_alloc_path();
1638 if (!path)
1639 return -ENOMEM;
1640
1641 if (sk->tree_id == 0) {
1642 /* search the root of the inode that was passed */
1643 root = BTRFS_I(inode)->root;
1644 } else {
1645 key.objectid = sk->tree_id;
1646 key.type = BTRFS_ROOT_ITEM_KEY;
1647 key.offset = (u64)-1;
1648 root = btrfs_read_fs_root_no_name(info, &key);
1649 if (IS_ERR(root)) {
1650 printk(KERN_ERR "could not find root %llu\n",
1651 sk->tree_id);
1652 btrfs_free_path(path);
1653 return -ENOENT;
1654 }
1655 }
1656
1657 key.objectid = sk->min_objectid;
1658 key.type = sk->min_type;
1659 key.offset = sk->min_offset;
1660
1661 max_key.objectid = sk->max_objectid;
1662 max_key.type = sk->max_type;
1663 max_key.offset = sk->max_offset;
1664
1665 path->keep_locks = 1;
1666
1667 while(1) {
1668 ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1669 sk->min_transid);
1670 if (ret != 0) {
1671 if (ret > 0)
1672 ret = 0;
1673 goto err;
1674 }
1675 ret = copy_to_sk(root, path, &key, sk, args->buf,
1676 &sk_offset, &num_found);
1677 btrfs_release_path(path);
1678 if (ret || num_found >= sk->nr_items)
1679 break;
1680
1681 }
1682 ret = 0;
1683 err:
1684 sk->nr_items = num_found;
1685 btrfs_free_path(path);
1686 return ret;
1687 }
1688
1689 static noinline int btrfs_ioctl_tree_search(struct file *file,
1690 void __user *argp)
1691 {
1692 struct btrfs_ioctl_search_args *args;
1693 struct inode *inode;
1694 int ret;
1695
1696 if (!capable(CAP_SYS_ADMIN))
1697 return -EPERM;
1698
1699 args = memdup_user(argp, sizeof(*args));
1700 if (IS_ERR(args))
1701 return PTR_ERR(args);
1702
1703 inode = fdentry(file)->d_inode;
1704 ret = search_ioctl(inode, args);
1705 if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1706 ret = -EFAULT;
1707 kfree(args);
1708 return ret;
1709 }
1710
1711 /*
1712 * Search INODE_REFs to identify path name of 'dirid' directory
1713 * in a 'tree_id' tree. and sets path name to 'name'.
1714 */
1715 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1716 u64 tree_id, u64 dirid, char *name)
1717 {
1718 struct btrfs_root *root;
1719 struct btrfs_key key;
1720 char *ptr;
1721 int ret = -1;
1722 int slot;
1723 int len;
1724 int total_len = 0;
1725 struct btrfs_inode_ref *iref;
1726 struct extent_buffer *l;
1727 struct btrfs_path *path;
1728
1729 if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1730 name[0]='\0';
1731 return 0;
1732 }
1733
1734 path = btrfs_alloc_path();
1735 if (!path)
1736 return -ENOMEM;
1737
1738 ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1739
1740 key.objectid = tree_id;
1741 key.type = BTRFS_ROOT_ITEM_KEY;
1742 key.offset = (u64)-1;
1743 root = btrfs_read_fs_root_no_name(info, &key);
1744 if (IS_ERR(root)) {
1745 printk(KERN_ERR "could not find root %llu\n", tree_id);
1746 ret = -ENOENT;
1747 goto out;
1748 }
1749
1750 key.objectid = dirid;
1751 key.type = BTRFS_INODE_REF_KEY;
1752 key.offset = (u64)-1;
1753
1754 while(1) {
1755 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1756 if (ret < 0)
1757 goto out;
1758
1759 l = path->nodes[0];
1760 slot = path->slots[0];
1761 if (ret > 0 && slot > 0)
1762 slot--;
1763 btrfs_item_key_to_cpu(l, &key, slot);
1764
1765 if (ret > 0 && (key.objectid != dirid ||
1766 key.type != BTRFS_INODE_REF_KEY)) {
1767 ret = -ENOENT;
1768 goto out;
1769 }
1770
1771 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1772 len = btrfs_inode_ref_name_len(l, iref);
1773 ptr -= len + 1;
1774 total_len += len + 1;
1775 if (ptr < name)
1776 goto out;
1777
1778 *(ptr + len) = '/';
1779 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1780
1781 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1782 break;
1783
1784 btrfs_release_path(path);
1785 key.objectid = key.offset;
1786 key.offset = (u64)-1;
1787 dirid = key.objectid;
1788 }
1789 if (ptr < name)
1790 goto out;
1791 memmove(name, ptr, total_len);
1792 name[total_len]='\0';
1793 ret = 0;
1794 out:
1795 btrfs_free_path(path);
1796 return ret;
1797 }
1798
1799 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1800 void __user *argp)
1801 {
1802 struct btrfs_ioctl_ino_lookup_args *args;
1803 struct inode *inode;
1804 int ret;
1805
1806 if (!capable(CAP_SYS_ADMIN))
1807 return -EPERM;
1808
1809 args = memdup_user(argp, sizeof(*args));
1810 if (IS_ERR(args))
1811 return PTR_ERR(args);
1812
1813 inode = fdentry(file)->d_inode;
1814
1815 if (args->treeid == 0)
1816 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
1817
1818 ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
1819 args->treeid, args->objectid,
1820 args->name);
1821
1822 if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1823 ret = -EFAULT;
1824
1825 kfree(args);
1826 return ret;
1827 }
1828
1829 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
1830 void __user *arg)
1831 {
1832 struct dentry *parent = fdentry(file);
1833 struct dentry *dentry;
1834 struct inode *dir = parent->d_inode;
1835 struct inode *inode;
1836 struct btrfs_root *root = BTRFS_I(dir)->root;
1837 struct btrfs_root *dest = NULL;
1838 struct btrfs_ioctl_vol_args *vol_args;
1839 struct btrfs_trans_handle *trans;
1840 int namelen;
1841 int ret;
1842 int err = 0;
1843
1844 vol_args = memdup_user(arg, sizeof(*vol_args));
1845 if (IS_ERR(vol_args))
1846 return PTR_ERR(vol_args);
1847
1848 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1849 namelen = strlen(vol_args->name);
1850 if (strchr(vol_args->name, '/') ||
1851 strncmp(vol_args->name, "..", namelen) == 0) {
1852 err = -EINVAL;
1853 goto out;
1854 }
1855
1856 err = mnt_want_write(file->f_path.mnt);
1857 if (err)
1858 goto out;
1859
1860 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
1861 dentry = lookup_one_len(vol_args->name, parent, namelen);
1862 if (IS_ERR(dentry)) {
1863 err = PTR_ERR(dentry);
1864 goto out_unlock_dir;
1865 }
1866
1867 if (!dentry->d_inode) {
1868 err = -ENOENT;
1869 goto out_dput;
1870 }
1871
1872 inode = dentry->d_inode;
1873 dest = BTRFS_I(inode)->root;
1874 if (!capable(CAP_SYS_ADMIN)){
1875 /*
1876 * Regular user. Only allow this with a special mount
1877 * option, when the user has write+exec access to the
1878 * subvol root, and when rmdir(2) would have been
1879 * allowed.
1880 *
1881 * Note that this is _not_ check that the subvol is
1882 * empty or doesn't contain data that we wouldn't
1883 * otherwise be able to delete.
1884 *
1885 * Users who want to delete empty subvols should try
1886 * rmdir(2).
1887 */
1888 err = -EPERM;
1889 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1890 goto out_dput;
1891
1892 /*
1893 * Do not allow deletion if the parent dir is the same
1894 * as the dir to be deleted. That means the ioctl
1895 * must be called on the dentry referencing the root
1896 * of the subvol, not a random directory contained
1897 * within it.
1898 */
1899 err = -EINVAL;
1900 if (root == dest)
1901 goto out_dput;
1902
1903 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
1904 if (err)
1905 goto out_dput;
1906
1907 /* check if subvolume may be deleted by a non-root user */
1908 err = btrfs_may_delete(dir, dentry, 1);
1909 if (err)
1910 goto out_dput;
1911 }
1912
1913 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1914 err = -EINVAL;
1915 goto out_dput;
1916 }
1917
1918 mutex_lock(&inode->i_mutex);
1919 err = d_invalidate(dentry);
1920 if (err)
1921 goto out_unlock;
1922
1923 down_write(&root->fs_info->subvol_sem);
1924
1925 err = may_destroy_subvol(dest);
1926 if (err)
1927 goto out_up_write;
1928
1929 trans = btrfs_start_transaction(root, 0);
1930 if (IS_ERR(trans)) {
1931 err = PTR_ERR(trans);
1932 goto out_up_write;
1933 }
1934 trans->block_rsv = &root->fs_info->global_block_rsv;
1935
1936 ret = btrfs_unlink_subvol(trans, root, dir,
1937 dest->root_key.objectid,
1938 dentry->d_name.name,
1939 dentry->d_name.len);
1940 BUG_ON(ret);
1941
1942 btrfs_record_root_in_trans(trans, dest);
1943
1944 memset(&dest->root_item.drop_progress, 0,
1945 sizeof(dest->root_item.drop_progress));
1946 dest->root_item.drop_level = 0;
1947 btrfs_set_root_refs(&dest->root_item, 0);
1948
1949 if (!xchg(&dest->orphan_item_inserted, 1)) {
1950 ret = btrfs_insert_orphan_item(trans,
1951 root->fs_info->tree_root,
1952 dest->root_key.objectid);
1953 BUG_ON(ret);
1954 }
1955
1956 ret = btrfs_end_transaction(trans, root);
1957 BUG_ON(ret);
1958 inode->i_flags |= S_DEAD;
1959 out_up_write:
1960 up_write(&root->fs_info->subvol_sem);
1961 out_unlock:
1962 mutex_unlock(&inode->i_mutex);
1963 if (!err) {
1964 shrink_dcache_sb(root->fs_info->sb);
1965 btrfs_invalidate_inodes(dest);
1966 d_delete(dentry);
1967 }
1968 out_dput:
1969 dput(dentry);
1970 out_unlock_dir:
1971 mutex_unlock(&dir->i_mutex);
1972 mnt_drop_write(file->f_path.mnt);
1973 out:
1974 kfree(vol_args);
1975 return err;
1976 }
1977
1978 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
1979 {
1980 struct inode *inode = fdentry(file)->d_inode;
1981 struct btrfs_root *root = BTRFS_I(inode)->root;
1982 struct btrfs_ioctl_defrag_range_args *range;
1983 int ret;
1984
1985 if (btrfs_root_readonly(root))
1986 return -EROFS;
1987
1988 ret = mnt_want_write(file->f_path.mnt);
1989 if (ret)
1990 return ret;
1991
1992 switch (inode->i_mode & S_IFMT) {
1993 case S_IFDIR:
1994 if (!capable(CAP_SYS_ADMIN)) {
1995 ret = -EPERM;
1996 goto out;
1997 }
1998 ret = btrfs_defrag_root(root, 0);
1999 if (ret)
2000 goto out;
2001 ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
2002 break;
2003 case S_IFREG:
2004 if (!(file->f_mode & FMODE_WRITE)) {
2005 ret = -EINVAL;
2006 goto out;
2007 }
2008
2009 range = kzalloc(sizeof(*range), GFP_KERNEL);
2010 if (!range) {
2011 ret = -ENOMEM;
2012 goto out;
2013 }
2014
2015 if (argp) {
2016 if (copy_from_user(range, argp,
2017 sizeof(*range))) {
2018 ret = -EFAULT;
2019 kfree(range);
2020 goto out;
2021 }
2022 /* compression requires us to start the IO */
2023 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2024 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2025 range->extent_thresh = (u32)-1;
2026 }
2027 } else {
2028 /* the rest are all set to zero by kzalloc */
2029 range->len = (u64)-1;
2030 }
2031 ret = btrfs_defrag_file(fdentry(file)->d_inode, file,
2032 range, 0, 0);
2033 if (ret > 0)
2034 ret = 0;
2035 kfree(range);
2036 break;
2037 default:
2038 ret = -EINVAL;
2039 }
2040 out:
2041 mnt_drop_write(file->f_path.mnt);
2042 return ret;
2043 }
2044
2045 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2046 {
2047 struct btrfs_ioctl_vol_args *vol_args;
2048 int ret;
2049
2050 if (!capable(CAP_SYS_ADMIN))
2051 return -EPERM;
2052
2053 vol_args = memdup_user(arg, sizeof(*vol_args));
2054 if (IS_ERR(vol_args))
2055 return PTR_ERR(vol_args);
2056
2057 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2058 ret = btrfs_init_new_device(root, vol_args->name);
2059
2060 kfree(vol_args);
2061 return ret;
2062 }
2063
2064 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
2065 {
2066 struct btrfs_ioctl_vol_args *vol_args;
2067 int ret;
2068
2069 if (!capable(CAP_SYS_ADMIN))
2070 return -EPERM;
2071
2072 if (root->fs_info->sb->s_flags & MS_RDONLY)
2073 return -EROFS;
2074
2075 vol_args = memdup_user(arg, sizeof(*vol_args));
2076 if (IS_ERR(vol_args))
2077 return PTR_ERR(vol_args);
2078
2079 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2080 ret = btrfs_rm_device(root, vol_args->name);
2081
2082 kfree(vol_args);
2083 return ret;
2084 }
2085
2086 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2087 {
2088 struct btrfs_ioctl_fs_info_args *fi_args;
2089 struct btrfs_device *device;
2090 struct btrfs_device *next;
2091 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2092 int ret = 0;
2093
2094 if (!capable(CAP_SYS_ADMIN))
2095 return -EPERM;
2096
2097 fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2098 if (!fi_args)
2099 return -ENOMEM;
2100
2101 fi_args->num_devices = fs_devices->num_devices;
2102 memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2103
2104 mutex_lock(&fs_devices->device_list_mutex);
2105 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
2106 if (device->devid > fi_args->max_id)
2107 fi_args->max_id = device->devid;
2108 }
2109 mutex_unlock(&fs_devices->device_list_mutex);
2110
2111 if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2112 ret = -EFAULT;
2113
2114 kfree(fi_args);
2115 return ret;
2116 }
2117
2118 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2119 {
2120 struct btrfs_ioctl_dev_info_args *di_args;
2121 struct btrfs_device *dev;
2122 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2123 int ret = 0;
2124 char *s_uuid = NULL;
2125 char empty_uuid[BTRFS_UUID_SIZE] = {0};
2126
2127 if (!capable(CAP_SYS_ADMIN))
2128 return -EPERM;
2129
2130 di_args = memdup_user(arg, sizeof(*di_args));
2131 if (IS_ERR(di_args))
2132 return PTR_ERR(di_args);
2133
2134 if (memcmp(empty_uuid, di_args->uuid, BTRFS_UUID_SIZE) != 0)
2135 s_uuid = di_args->uuid;
2136
2137 mutex_lock(&fs_devices->device_list_mutex);
2138 dev = btrfs_find_device(root, di_args->devid, s_uuid, NULL);
2139 mutex_unlock(&fs_devices->device_list_mutex);
2140
2141 if (!dev) {
2142 ret = -ENODEV;
2143 goto out;
2144 }
2145
2146 di_args->devid = dev->devid;
2147 di_args->bytes_used = dev->bytes_used;
2148 di_args->total_bytes = dev->total_bytes;
2149 memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2150 strncpy(di_args->path, dev->name, sizeof(di_args->path));
2151
2152 out:
2153 if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2154 ret = -EFAULT;
2155
2156 kfree(di_args);
2157 return ret;
2158 }
2159
2160 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
2161 u64 off, u64 olen, u64 destoff)
2162 {
2163 struct inode *inode = fdentry(file)->d_inode;
2164 struct btrfs_root *root = BTRFS_I(inode)->root;
2165 struct file *src_file;
2166 struct inode *src;
2167 struct btrfs_trans_handle *trans;
2168 struct btrfs_path *path;
2169 struct extent_buffer *leaf;
2170 char *buf;
2171 struct btrfs_key key;
2172 u32 nritems;
2173 int slot;
2174 int ret;
2175 u64 len = olen;
2176 u64 bs = root->fs_info->sb->s_blocksize;
2177 u64 hint_byte;
2178
2179 /*
2180 * TODO:
2181 * - split compressed inline extents. annoying: we need to
2182 * decompress into destination's address_space (the file offset
2183 * may change, so source mapping won't do), then recompress (or
2184 * otherwise reinsert) a subrange.
2185 * - allow ranges within the same file to be cloned (provided
2186 * they don't overlap)?
2187 */
2188
2189 /* the destination must be opened for writing */
2190 if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
2191 return -EINVAL;
2192
2193 if (btrfs_root_readonly(root))
2194 return -EROFS;
2195
2196 ret = mnt_want_write(file->f_path.mnt);
2197 if (ret)
2198 return ret;
2199
2200 src_file = fget(srcfd);
2201 if (!src_file) {
2202 ret = -EBADF;
2203 goto out_drop_write;
2204 }
2205
2206 src = src_file->f_dentry->d_inode;
2207
2208 ret = -EINVAL;
2209 if (src == inode)
2210 goto out_fput;
2211
2212 /* the src must be open for reading */
2213 if (!(src_file->f_mode & FMODE_READ))
2214 goto out_fput;
2215
2216 /* don't make the dst file partly checksummed */
2217 if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
2218 (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
2219 goto out_fput;
2220
2221 ret = -EISDIR;
2222 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
2223 goto out_fput;
2224
2225 ret = -EXDEV;
2226 if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
2227 goto out_fput;
2228
2229 ret = -ENOMEM;
2230 buf = vmalloc(btrfs_level_size(root, 0));
2231 if (!buf)
2232 goto out_fput;
2233
2234 path = btrfs_alloc_path();
2235 if (!path) {
2236 vfree(buf);
2237 goto out_fput;
2238 }
2239 path->reada = 2;
2240
2241 if (inode < src) {
2242 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
2243 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
2244 } else {
2245 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
2246 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
2247 }
2248
2249 /* determine range to clone */
2250 ret = -EINVAL;
2251 if (off + len > src->i_size || off + len < off)
2252 goto out_unlock;
2253 if (len == 0)
2254 olen = len = src->i_size - off;
2255 /* if we extend to eof, continue to block boundary */
2256 if (off + len == src->i_size)
2257 len = ALIGN(src->i_size, bs) - off;
2258
2259 /* verify the end result is block aligned */
2260 if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
2261 !IS_ALIGNED(destoff, bs))
2262 goto out_unlock;
2263
2264 if (destoff > inode->i_size) {
2265 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
2266 if (ret)
2267 goto out_unlock;
2268 }
2269
2270 /* truncate page cache pages from target inode range */
2271 truncate_inode_pages_range(&inode->i_data, destoff,
2272 PAGE_CACHE_ALIGN(destoff + len) - 1);
2273
2274 /* do any pending delalloc/csum calc on src, one way or
2275 another, and lock file content */
2276 while (1) {
2277 struct btrfs_ordered_extent *ordered;
2278 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2279 ordered = btrfs_lookup_first_ordered_extent(src, off+len);
2280 if (!ordered &&
2281 !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len,
2282 EXTENT_DELALLOC, 0, NULL))
2283 break;
2284 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2285 if (ordered)
2286 btrfs_put_ordered_extent(ordered);
2287 btrfs_wait_ordered_range(src, off, len);
2288 }
2289
2290 /* clone data */
2291 key.objectid = btrfs_ino(src);
2292 key.type = BTRFS_EXTENT_DATA_KEY;
2293 key.offset = 0;
2294
2295 while (1) {
2296 /*
2297 * note the key will change type as we walk through the
2298 * tree.
2299 */
2300 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2301 if (ret < 0)
2302 goto out;
2303
2304 nritems = btrfs_header_nritems(path->nodes[0]);
2305 if (path->slots[0] >= nritems) {
2306 ret = btrfs_next_leaf(root, path);
2307 if (ret < 0)
2308 goto out;
2309 if (ret > 0)
2310 break;
2311 nritems = btrfs_header_nritems(path->nodes[0]);
2312 }
2313 leaf = path->nodes[0];
2314 slot = path->slots[0];
2315
2316 btrfs_item_key_to_cpu(leaf, &key, slot);
2317 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
2318 key.objectid != btrfs_ino(src))
2319 break;
2320
2321 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
2322 struct btrfs_file_extent_item *extent;
2323 int type;
2324 u32 size;
2325 struct btrfs_key new_key;
2326 u64 disko = 0, diskl = 0;
2327 u64 datao = 0, datal = 0;
2328 u8 comp;
2329 u64 endoff;
2330
2331 size = btrfs_item_size_nr(leaf, slot);
2332 read_extent_buffer(leaf, buf,
2333 btrfs_item_ptr_offset(leaf, slot),
2334 size);
2335
2336 extent = btrfs_item_ptr(leaf, slot,
2337 struct btrfs_file_extent_item);
2338 comp = btrfs_file_extent_compression(leaf, extent);
2339 type = btrfs_file_extent_type(leaf, extent);
2340 if (type == BTRFS_FILE_EXTENT_REG ||
2341 type == BTRFS_FILE_EXTENT_PREALLOC) {
2342 disko = btrfs_file_extent_disk_bytenr(leaf,
2343 extent);
2344 diskl = btrfs_file_extent_disk_num_bytes(leaf,
2345 extent);
2346 datao = btrfs_file_extent_offset(leaf, extent);
2347 datal = btrfs_file_extent_num_bytes(leaf,
2348 extent);
2349 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2350 /* take upper bound, may be compressed */
2351 datal = btrfs_file_extent_ram_bytes(leaf,
2352 extent);
2353 }
2354 btrfs_release_path(path);
2355
2356 if (key.offset + datal <= off ||
2357 key.offset >= off+len)
2358 goto next;
2359
2360 memcpy(&new_key, &key, sizeof(new_key));
2361 new_key.objectid = btrfs_ino(inode);
2362 if (off <= key.offset)
2363 new_key.offset = key.offset + destoff - off;
2364 else
2365 new_key.offset = destoff;
2366
2367 /*
2368 * 1 - adjusting old extent (we may have to split it)
2369 * 1 - add new extent
2370 * 1 - inode update
2371 */
2372 trans = btrfs_start_transaction(root, 3);
2373 if (IS_ERR(trans)) {
2374 ret = PTR_ERR(trans);
2375 goto out;
2376 }
2377
2378 if (type == BTRFS_FILE_EXTENT_REG ||
2379 type == BTRFS_FILE_EXTENT_PREALLOC) {
2380 /*
2381 * a | --- range to clone ---| b
2382 * | ------------- extent ------------- |
2383 */
2384
2385 /* substract range b */
2386 if (key.offset + datal > off + len)
2387 datal = off + len - key.offset;
2388
2389 /* substract range a */
2390 if (off > key.offset) {
2391 datao += off - key.offset;
2392 datal -= off - key.offset;
2393 }
2394
2395 ret = btrfs_drop_extents(trans, inode,
2396 new_key.offset,
2397 new_key.offset + datal,
2398 &hint_byte, 1);
2399 BUG_ON(ret);
2400
2401 ret = btrfs_insert_empty_item(trans, root, path,
2402 &new_key, size);
2403 BUG_ON(ret);
2404
2405 leaf = path->nodes[0];
2406 slot = path->slots[0];
2407 write_extent_buffer(leaf, buf,
2408 btrfs_item_ptr_offset(leaf, slot),
2409 size);
2410
2411 extent = btrfs_item_ptr(leaf, slot,
2412 struct btrfs_file_extent_item);
2413
2414 /* disko == 0 means it's a hole */
2415 if (!disko)
2416 datao = 0;
2417
2418 btrfs_set_file_extent_offset(leaf, extent,
2419 datao);
2420 btrfs_set_file_extent_num_bytes(leaf, extent,
2421 datal);
2422 if (disko) {
2423 inode_add_bytes(inode, datal);
2424 ret = btrfs_inc_extent_ref(trans, root,
2425 disko, diskl, 0,
2426 root->root_key.objectid,
2427 btrfs_ino(inode),
2428 new_key.offset - datao);
2429 BUG_ON(ret);
2430 }
2431 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2432 u64 skip = 0;
2433 u64 trim = 0;
2434 if (off > key.offset) {
2435 skip = off - key.offset;
2436 new_key.offset += skip;
2437 }
2438
2439 if (key.offset + datal > off+len)
2440 trim = key.offset + datal - (off+len);
2441
2442 if (comp && (skip || trim)) {
2443 ret = -EINVAL;
2444 btrfs_end_transaction(trans, root);
2445 goto out;
2446 }
2447 size -= skip + trim;
2448 datal -= skip + trim;
2449
2450 ret = btrfs_drop_extents(trans, inode,
2451 new_key.offset,
2452 new_key.offset + datal,
2453 &hint_byte, 1);
2454 BUG_ON(ret);
2455
2456 ret = btrfs_insert_empty_item(trans, root, path,
2457 &new_key, size);
2458 BUG_ON(ret);
2459
2460 if (skip) {
2461 u32 start =
2462 btrfs_file_extent_calc_inline_size(0);
2463 memmove(buf+start, buf+start+skip,
2464 datal);
2465 }
2466
2467 leaf = path->nodes[0];
2468 slot = path->slots[0];
2469 write_extent_buffer(leaf, buf,
2470 btrfs_item_ptr_offset(leaf, slot),
2471 size);
2472 inode_add_bytes(inode, datal);
2473 }
2474
2475 btrfs_mark_buffer_dirty(leaf);
2476 btrfs_release_path(path);
2477
2478 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2479
2480 /*
2481 * we round up to the block size at eof when
2482 * determining which extents to clone above,
2483 * but shouldn't round up the file size
2484 */
2485 endoff = new_key.offset + datal;
2486 if (endoff > destoff+olen)
2487 endoff = destoff+olen;
2488 if (endoff > inode->i_size)
2489 btrfs_i_size_write(inode, endoff);
2490
2491 ret = btrfs_update_inode(trans, root, inode);
2492 BUG_ON(ret);
2493 btrfs_end_transaction(trans, root);
2494 }
2495 next:
2496 btrfs_release_path(path);
2497 key.offset++;
2498 }
2499 ret = 0;
2500 out:
2501 btrfs_release_path(path);
2502 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2503 out_unlock:
2504 mutex_unlock(&src->i_mutex);
2505 mutex_unlock(&inode->i_mutex);
2506 vfree(buf);
2507 btrfs_free_path(path);
2508 out_fput:
2509 fput(src_file);
2510 out_drop_write:
2511 mnt_drop_write(file->f_path.mnt);
2512 return ret;
2513 }
2514
2515 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2516 {
2517 struct btrfs_ioctl_clone_range_args args;
2518
2519 if (copy_from_user(&args, argp, sizeof(args)))
2520 return -EFAULT;
2521 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2522 args.src_length, args.dest_offset);
2523 }
2524
2525 /*
2526 * there are many ways the trans_start and trans_end ioctls can lead
2527 * to deadlocks. They should only be used by applications that
2528 * basically own the machine, and have a very in depth understanding
2529 * of all the possible deadlocks and enospc problems.
2530 */
2531 static long btrfs_ioctl_trans_start(struct file *file)
2532 {
2533 struct inode *inode = fdentry(file)->d_inode;
2534 struct btrfs_root *root = BTRFS_I(inode)->root;
2535 struct btrfs_trans_handle *trans;
2536 int ret;
2537
2538 ret = -EPERM;
2539 if (!capable(CAP_SYS_ADMIN))
2540 goto out;
2541
2542 ret = -EINPROGRESS;
2543 if (file->private_data)
2544 goto out;
2545
2546 ret = -EROFS;
2547 if (btrfs_root_readonly(root))
2548 goto out;
2549
2550 ret = mnt_want_write(file->f_path.mnt);
2551 if (ret)
2552 goto out;
2553
2554 atomic_inc(&root->fs_info->open_ioctl_trans);
2555
2556 ret = -ENOMEM;
2557 trans = btrfs_start_ioctl_transaction(root);
2558 if (IS_ERR(trans))
2559 goto out_drop;
2560
2561 file->private_data = trans;
2562 return 0;
2563
2564 out_drop:
2565 atomic_dec(&root->fs_info->open_ioctl_trans);
2566 mnt_drop_write(file->f_path.mnt);
2567 out:
2568 return ret;
2569 }
2570
2571 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2572 {
2573 struct inode *inode = fdentry(file)->d_inode;
2574 struct btrfs_root *root = BTRFS_I(inode)->root;
2575 struct btrfs_root *new_root;
2576 struct btrfs_dir_item *di;
2577 struct btrfs_trans_handle *trans;
2578 struct btrfs_path *path;
2579 struct btrfs_key location;
2580 struct btrfs_disk_key disk_key;
2581 struct btrfs_super_block *disk_super;
2582 u64 features;
2583 u64 objectid = 0;
2584 u64 dir_id;
2585
2586 if (!capable(CAP_SYS_ADMIN))
2587 return -EPERM;
2588
2589 if (copy_from_user(&objectid, argp, sizeof(objectid)))
2590 return -EFAULT;
2591
2592 if (!objectid)
2593 objectid = root->root_key.objectid;
2594
2595 location.objectid = objectid;
2596 location.type = BTRFS_ROOT_ITEM_KEY;
2597 location.offset = (u64)-1;
2598
2599 new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2600 if (IS_ERR(new_root))
2601 return PTR_ERR(new_root);
2602
2603 if (btrfs_root_refs(&new_root->root_item) == 0)
2604 return -ENOENT;
2605
2606 path = btrfs_alloc_path();
2607 if (!path)
2608 return -ENOMEM;
2609 path->leave_spinning = 1;
2610
2611 trans = btrfs_start_transaction(root, 1);
2612 if (IS_ERR(trans)) {
2613 btrfs_free_path(path);
2614 return PTR_ERR(trans);
2615 }
2616
2617 dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
2618 di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2619 dir_id, "default", 7, 1);
2620 if (IS_ERR_OR_NULL(di)) {
2621 btrfs_free_path(path);
2622 btrfs_end_transaction(trans, root);
2623 printk(KERN_ERR "Umm, you don't have the default dir item, "
2624 "this isn't going to work\n");
2625 return -ENOENT;
2626 }
2627
2628 btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2629 btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2630 btrfs_mark_buffer_dirty(path->nodes[0]);
2631 btrfs_free_path(path);
2632
2633 disk_super = root->fs_info->super_copy;
2634 features = btrfs_super_incompat_flags(disk_super);
2635 if (!(features & BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)) {
2636 features |= BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL;
2637 btrfs_set_super_incompat_flags(disk_super, features);
2638 }
2639 btrfs_end_transaction(trans, root);
2640
2641 return 0;
2642 }
2643
2644 static void get_block_group_info(struct list_head *groups_list,
2645 struct btrfs_ioctl_space_info *space)
2646 {
2647 struct btrfs_block_group_cache *block_group;
2648
2649 space->total_bytes = 0;
2650 space->used_bytes = 0;
2651 space->flags = 0;
2652 list_for_each_entry(block_group, groups_list, list) {
2653 space->flags = block_group->flags;
2654 space->total_bytes += block_group->key.offset;
2655 space->used_bytes +=
2656 btrfs_block_group_used(&block_group->item);
2657 }
2658 }
2659
2660 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
2661 {
2662 struct btrfs_ioctl_space_args space_args;
2663 struct btrfs_ioctl_space_info space;
2664 struct btrfs_ioctl_space_info *dest;
2665 struct btrfs_ioctl_space_info *dest_orig;
2666 struct btrfs_ioctl_space_info __user *user_dest;
2667 struct btrfs_space_info *info;
2668 u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2669 BTRFS_BLOCK_GROUP_SYSTEM,
2670 BTRFS_BLOCK_GROUP_METADATA,
2671 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2672 int num_types = 4;
2673 int alloc_size;
2674 int ret = 0;
2675 u64 slot_count = 0;
2676 int i, c;
2677
2678 if (copy_from_user(&space_args,
2679 (struct btrfs_ioctl_space_args __user *)arg,
2680 sizeof(space_args)))
2681 return -EFAULT;
2682
2683 for (i = 0; i < num_types; i++) {
2684 struct btrfs_space_info *tmp;
2685
2686 info = NULL;
2687 rcu_read_lock();
2688 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2689 list) {
2690 if (tmp->flags == types[i]) {
2691 info = tmp;
2692 break;
2693 }
2694 }
2695 rcu_read_unlock();
2696
2697 if (!info)
2698 continue;
2699
2700 down_read(&info->groups_sem);
2701 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2702 if (!list_empty(&info->block_groups[c]))
2703 slot_count++;
2704 }
2705 up_read(&info->groups_sem);
2706 }
2707
2708 /* space_slots == 0 means they are asking for a count */
2709 if (space_args.space_slots == 0) {
2710 space_args.total_spaces = slot_count;
2711 goto out;
2712 }
2713
2714 slot_count = min_t(u64, space_args.space_slots, slot_count);
2715
2716 alloc_size = sizeof(*dest) * slot_count;
2717
2718 /* we generally have at most 6 or so space infos, one for each raid
2719 * level. So, a whole page should be more than enough for everyone
2720 */
2721 if (alloc_size > PAGE_CACHE_SIZE)
2722 return -ENOMEM;
2723
2724 space_args.total_spaces = 0;
2725 dest = kmalloc(alloc_size, GFP_NOFS);
2726 if (!dest)
2727 return -ENOMEM;
2728 dest_orig = dest;
2729
2730 /* now we have a buffer to copy into */
2731 for (i = 0; i < num_types; i++) {
2732 struct btrfs_space_info *tmp;
2733
2734 if (!slot_count)
2735 break;
2736
2737 info = NULL;
2738 rcu_read_lock();
2739 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2740 list) {
2741 if (tmp->flags == types[i]) {
2742 info = tmp;
2743 break;
2744 }
2745 }
2746 rcu_read_unlock();
2747
2748 if (!info)
2749 continue;
2750 down_read(&info->groups_sem);
2751 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2752 if (!list_empty(&info->block_groups[c])) {
2753 get_block_group_info(&info->block_groups[c],
2754 &space);
2755 memcpy(dest, &space, sizeof(space));
2756 dest++;
2757 space_args.total_spaces++;
2758 slot_count--;
2759 }
2760 if (!slot_count)
2761 break;
2762 }
2763 up_read(&info->groups_sem);
2764 }
2765
2766 user_dest = (struct btrfs_ioctl_space_info *)
2767 (arg + sizeof(struct btrfs_ioctl_space_args));
2768
2769 if (copy_to_user(user_dest, dest_orig, alloc_size))
2770 ret = -EFAULT;
2771
2772 kfree(dest_orig);
2773 out:
2774 if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
2775 ret = -EFAULT;
2776
2777 return ret;
2778 }
2779
2780 /*
2781 * there are many ways the trans_start and trans_end ioctls can lead
2782 * to deadlocks. They should only be used by applications that
2783 * basically own the machine, and have a very in depth understanding
2784 * of all the possible deadlocks and enospc problems.
2785 */
2786 long btrfs_ioctl_trans_end(struct file *file)
2787 {
2788 struct inode *inode = fdentry(file)->d_inode;
2789 struct btrfs_root *root = BTRFS_I(inode)->root;
2790 struct btrfs_trans_handle *trans;
2791
2792 trans = file->private_data;
2793 if (!trans)
2794 return -EINVAL;
2795 file->private_data = NULL;
2796
2797 btrfs_end_transaction(trans, root);
2798
2799 atomic_dec(&root->fs_info->open_ioctl_trans);
2800
2801 mnt_drop_write(file->f_path.mnt);
2802 return 0;
2803 }
2804
2805 static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp)
2806 {
2807 struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2808 struct btrfs_trans_handle *trans;
2809 u64 transid;
2810 int ret;
2811
2812 trans = btrfs_start_transaction(root, 0);
2813 if (IS_ERR(trans))
2814 return PTR_ERR(trans);
2815 transid = trans->transid;
2816 ret = btrfs_commit_transaction_async(trans, root, 0);
2817 if (ret) {
2818 btrfs_end_transaction(trans, root);
2819 return ret;
2820 }
2821
2822 if (argp)
2823 if (copy_to_user(argp, &transid, sizeof(transid)))
2824 return -EFAULT;
2825 return 0;
2826 }
2827
2828 static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp)
2829 {
2830 struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2831 u64 transid;
2832
2833 if (argp) {
2834 if (copy_from_user(&transid, argp, sizeof(transid)))
2835 return -EFAULT;
2836 } else {
2837 transid = 0; /* current trans */
2838 }
2839 return btrfs_wait_for_commit(root, transid);
2840 }
2841
2842 static long btrfs_ioctl_scrub(struct btrfs_root *root, void __user *arg)
2843 {
2844 int ret;
2845 struct btrfs_ioctl_scrub_args *sa;
2846
2847 if (!capable(CAP_SYS_ADMIN))
2848 return -EPERM;
2849
2850 sa = memdup_user(arg, sizeof(*sa));
2851 if (IS_ERR(sa))
2852 return PTR_ERR(sa);
2853
2854 ret = btrfs_scrub_dev(root, sa->devid, sa->start, sa->end,
2855 &sa->progress, sa->flags & BTRFS_SCRUB_READONLY);
2856
2857 if (copy_to_user(arg, sa, sizeof(*sa)))
2858 ret = -EFAULT;
2859
2860 kfree(sa);
2861 return ret;
2862 }
2863
2864 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
2865 {
2866 if (!capable(CAP_SYS_ADMIN))
2867 return -EPERM;
2868
2869 return btrfs_scrub_cancel(root);
2870 }
2871
2872 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
2873 void __user *arg)
2874 {
2875 struct btrfs_ioctl_scrub_args *sa;
2876 int ret;
2877
2878 if (!capable(CAP_SYS_ADMIN))
2879 return -EPERM;
2880
2881 sa = memdup_user(arg, sizeof(*sa));
2882 if (IS_ERR(sa))
2883 return PTR_ERR(sa);
2884
2885 ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
2886
2887 if (copy_to_user(arg, sa, sizeof(*sa)))
2888 ret = -EFAULT;
2889
2890 kfree(sa);
2891 return ret;
2892 }
2893
2894 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
2895 {
2896 int ret = 0;
2897 int i;
2898 u64 rel_ptr;
2899 int size;
2900 struct btrfs_ioctl_ino_path_args *ipa = NULL;
2901 struct inode_fs_paths *ipath = NULL;
2902 struct btrfs_path *path;
2903
2904 if (!capable(CAP_SYS_ADMIN))
2905 return -EPERM;
2906
2907 path = btrfs_alloc_path();
2908 if (!path) {
2909 ret = -ENOMEM;
2910 goto out;
2911 }
2912
2913 ipa = memdup_user(arg, sizeof(*ipa));
2914 if (IS_ERR(ipa)) {
2915 ret = PTR_ERR(ipa);
2916 ipa = NULL;
2917 goto out;
2918 }
2919
2920 size = min_t(u32, ipa->size, 4096);
2921 ipath = init_ipath(size, root, path);
2922 if (IS_ERR(ipath)) {
2923 ret = PTR_ERR(ipath);
2924 ipath = NULL;
2925 goto out;
2926 }
2927
2928 ret = paths_from_inode(ipa->inum, ipath);
2929 if (ret < 0)
2930 goto out;
2931
2932 for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
2933 rel_ptr = ipath->fspath->val[i] -
2934 (u64)(unsigned long)ipath->fspath->val;
2935 ipath->fspath->val[i] = rel_ptr;
2936 }
2937
2938 ret = copy_to_user((void *)(unsigned long)ipa->fspath,
2939 (void *)(unsigned long)ipath->fspath, size);
2940 if (ret) {
2941 ret = -EFAULT;
2942 goto out;
2943 }
2944
2945 out:
2946 btrfs_free_path(path);
2947 free_ipath(ipath);
2948 kfree(ipa);
2949
2950 return ret;
2951 }
2952
2953 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
2954 {
2955 struct btrfs_data_container *inodes = ctx;
2956 const size_t c = 3 * sizeof(u64);
2957
2958 if (inodes->bytes_left >= c) {
2959 inodes->bytes_left -= c;
2960 inodes->val[inodes->elem_cnt] = inum;
2961 inodes->val[inodes->elem_cnt + 1] = offset;
2962 inodes->val[inodes->elem_cnt + 2] = root;
2963 inodes->elem_cnt += 3;
2964 } else {
2965 inodes->bytes_missing += c - inodes->bytes_left;
2966 inodes->bytes_left = 0;
2967 inodes->elem_missed += 3;
2968 }
2969
2970 return 0;
2971 }
2972
2973 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
2974 void __user *arg)
2975 {
2976 int ret = 0;
2977 int size;
2978 u64 extent_offset;
2979 struct btrfs_ioctl_logical_ino_args *loi;
2980 struct btrfs_data_container *inodes = NULL;
2981 struct btrfs_path *path = NULL;
2982 struct btrfs_key key;
2983
2984 if (!capable(CAP_SYS_ADMIN))
2985 return -EPERM;
2986
2987 loi = memdup_user(arg, sizeof(*loi));
2988 if (IS_ERR(loi)) {
2989 ret = PTR_ERR(loi);
2990 loi = NULL;
2991 goto out;
2992 }
2993
2994 path = btrfs_alloc_path();
2995 if (!path) {
2996 ret = -ENOMEM;
2997 goto out;
2998 }
2999
3000 size = min_t(u32, loi->size, 4096);
3001 inodes = init_data_container(size);
3002 if (IS_ERR(inodes)) {
3003 ret = PTR_ERR(inodes);
3004 inodes = NULL;
3005 goto out;
3006 }
3007
3008 ret = extent_from_logical(root->fs_info, loi->logical, path, &key);
3009
3010 if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK)
3011 ret = -ENOENT;
3012 if (ret < 0)
3013 goto out;
3014
3015 extent_offset = loi->logical - key.objectid;
3016 ret = iterate_extent_inodes(root->fs_info, path, key.objectid,
3017 extent_offset, build_ino_list, inodes);
3018
3019 if (ret < 0)
3020 goto out;
3021
3022 ret = copy_to_user((void *)(unsigned long)loi->inodes,
3023 (void *)(unsigned long)inodes, size);
3024 if (ret)
3025 ret = -EFAULT;
3026
3027 out:
3028 btrfs_free_path(path);
3029 kfree(inodes);
3030 kfree(loi);
3031
3032 return ret;
3033 }
3034
3035 long btrfs_ioctl(struct file *file, unsigned int
3036 cmd, unsigned long arg)
3037 {
3038 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3039 void __user *argp = (void __user *)arg;
3040
3041 switch (cmd) {
3042 case FS_IOC_GETFLAGS:
3043 return btrfs_ioctl_getflags(file, argp);
3044 case FS_IOC_SETFLAGS:
3045 return btrfs_ioctl_setflags(file, argp);
3046 case FS_IOC_GETVERSION:
3047 return btrfs_ioctl_getversion(file, argp);
3048 case FITRIM:
3049 return btrfs_ioctl_fitrim(file, argp);
3050 case BTRFS_IOC_SNAP_CREATE:
3051 return btrfs_ioctl_snap_create(file, argp, 0);
3052 case BTRFS_IOC_SNAP_CREATE_V2:
3053 return btrfs_ioctl_snap_create_v2(file, argp, 0);
3054 case BTRFS_IOC_SUBVOL_CREATE:
3055 return btrfs_ioctl_snap_create(file, argp, 1);
3056 case BTRFS_IOC_SNAP_DESTROY:
3057 return btrfs_ioctl_snap_destroy(file, argp);
3058 case BTRFS_IOC_SUBVOL_GETFLAGS:
3059 return btrfs_ioctl_subvol_getflags(file, argp);
3060 case BTRFS_IOC_SUBVOL_SETFLAGS:
3061 return btrfs_ioctl_subvol_setflags(file, argp);
3062 case BTRFS_IOC_DEFAULT_SUBVOL:
3063 return btrfs_ioctl_default_subvol(file, argp);
3064 case BTRFS_IOC_DEFRAG:
3065 return btrfs_ioctl_defrag(file, NULL);
3066 case BTRFS_IOC_DEFRAG_RANGE:
3067 return btrfs_ioctl_defrag(file, argp);
3068 case BTRFS_IOC_RESIZE:
3069 return btrfs_ioctl_resize(root, argp);
3070 case BTRFS_IOC_ADD_DEV:
3071 return btrfs_ioctl_add_dev(root, argp);
3072 case BTRFS_IOC_RM_DEV:
3073 return btrfs_ioctl_rm_dev(root, argp);
3074 case BTRFS_IOC_FS_INFO:
3075 return btrfs_ioctl_fs_info(root, argp);
3076 case BTRFS_IOC_DEV_INFO:
3077 return btrfs_ioctl_dev_info(root, argp);
3078 case BTRFS_IOC_BALANCE:
3079 return btrfs_balance(root->fs_info->dev_root);
3080 case BTRFS_IOC_CLONE:
3081 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
3082 case BTRFS_IOC_CLONE_RANGE:
3083 return btrfs_ioctl_clone_range(file, argp);
3084 case BTRFS_IOC_TRANS_START:
3085 return btrfs_ioctl_trans_start(file);
3086 case BTRFS_IOC_TRANS_END:
3087 return btrfs_ioctl_trans_end(file);
3088 case BTRFS_IOC_TREE_SEARCH:
3089 return btrfs_ioctl_tree_search(file, argp);
3090 case BTRFS_IOC_INO_LOOKUP:
3091 return btrfs_ioctl_ino_lookup(file, argp);
3092 case BTRFS_IOC_INO_PATHS:
3093 return btrfs_ioctl_ino_to_path(root, argp);
3094 case BTRFS_IOC_LOGICAL_INO:
3095 return btrfs_ioctl_logical_to_ino(root, argp);
3096 case BTRFS_IOC_SPACE_INFO:
3097 return btrfs_ioctl_space_info(root, argp);
3098 case BTRFS_IOC_SYNC:
3099 btrfs_sync_fs(file->f_dentry->d_sb, 1);
3100 return 0;
3101 case BTRFS_IOC_START_SYNC:
3102 return btrfs_ioctl_start_sync(file, argp);
3103 case BTRFS_IOC_WAIT_SYNC:
3104 return btrfs_ioctl_wait_sync(file, argp);
3105 case BTRFS_IOC_SCRUB:
3106 return btrfs_ioctl_scrub(root, argp);
3107 case BTRFS_IOC_SCRUB_CANCEL:
3108 return btrfs_ioctl_scrub_cancel(root, argp);
3109 case BTRFS_IOC_SCRUB_PROGRESS:
3110 return btrfs_ioctl_scrub_progress(root, argp);
3111 }
3112
3113 return -ENOTTY;
3114 }