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Merge branch 'for-john' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211
[mirror_ubuntu-zesty-kernel.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/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 <linux/uuid.h>
45 #include "compat.h"
46 #include "ctree.h"
47 #include "disk-io.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "ioctl.h"
51 #include "print-tree.h"
52 #include "volumes.h"
53 #include "locking.h"
54 #include "inode-map.h"
55 #include "backref.h"
56 #include "rcu-string.h"
57 #include "send.h"
58
59 /* Mask out flags that are inappropriate for the given type of inode. */
60 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
61 {
62 if (S_ISDIR(mode))
63 return flags;
64 else if (S_ISREG(mode))
65 return flags & ~FS_DIRSYNC_FL;
66 else
67 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
68 }
69
70 /*
71 * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
72 */
73 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
74 {
75 unsigned int iflags = 0;
76
77 if (flags & BTRFS_INODE_SYNC)
78 iflags |= FS_SYNC_FL;
79 if (flags & BTRFS_INODE_IMMUTABLE)
80 iflags |= FS_IMMUTABLE_FL;
81 if (flags & BTRFS_INODE_APPEND)
82 iflags |= FS_APPEND_FL;
83 if (flags & BTRFS_INODE_NODUMP)
84 iflags |= FS_NODUMP_FL;
85 if (flags & BTRFS_INODE_NOATIME)
86 iflags |= FS_NOATIME_FL;
87 if (flags & BTRFS_INODE_DIRSYNC)
88 iflags |= FS_DIRSYNC_FL;
89 if (flags & BTRFS_INODE_NODATACOW)
90 iflags |= FS_NOCOW_FL;
91
92 if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS))
93 iflags |= FS_COMPR_FL;
94 else if (flags & BTRFS_INODE_NOCOMPRESS)
95 iflags |= FS_NOCOMP_FL;
96
97 return iflags;
98 }
99
100 /*
101 * Update inode->i_flags based on the btrfs internal flags.
102 */
103 void btrfs_update_iflags(struct inode *inode)
104 {
105 struct btrfs_inode *ip = BTRFS_I(inode);
106
107 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
108
109 if (ip->flags & BTRFS_INODE_SYNC)
110 inode->i_flags |= S_SYNC;
111 if (ip->flags & BTRFS_INODE_IMMUTABLE)
112 inode->i_flags |= S_IMMUTABLE;
113 if (ip->flags & BTRFS_INODE_APPEND)
114 inode->i_flags |= S_APPEND;
115 if (ip->flags & BTRFS_INODE_NOATIME)
116 inode->i_flags |= S_NOATIME;
117 if (ip->flags & BTRFS_INODE_DIRSYNC)
118 inode->i_flags |= S_DIRSYNC;
119 }
120
121 /*
122 * Inherit flags from the parent inode.
123 *
124 * Currently only the compression flags and the cow flags are inherited.
125 */
126 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
127 {
128 unsigned int flags;
129
130 if (!dir)
131 return;
132
133 flags = BTRFS_I(dir)->flags;
134
135 if (flags & BTRFS_INODE_NOCOMPRESS) {
136 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
137 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
138 } else if (flags & BTRFS_INODE_COMPRESS) {
139 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
140 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
141 }
142
143 if (flags & BTRFS_INODE_NODATACOW)
144 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
145
146 btrfs_update_iflags(inode);
147 }
148
149 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
150 {
151 struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode);
152 unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
153
154 if (copy_to_user(arg, &flags, sizeof(flags)))
155 return -EFAULT;
156 return 0;
157 }
158
159 static int check_flags(unsigned int flags)
160 {
161 if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
162 FS_NOATIME_FL | FS_NODUMP_FL | \
163 FS_SYNC_FL | FS_DIRSYNC_FL | \
164 FS_NOCOMP_FL | FS_COMPR_FL |
165 FS_NOCOW_FL))
166 return -EOPNOTSUPP;
167
168 if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
169 return -EINVAL;
170
171 return 0;
172 }
173
174 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
175 {
176 struct inode *inode = file->f_path.dentry->d_inode;
177 struct btrfs_inode *ip = BTRFS_I(inode);
178 struct btrfs_root *root = ip->root;
179 struct btrfs_trans_handle *trans;
180 unsigned int flags, oldflags;
181 int ret;
182 u64 ip_oldflags;
183 unsigned int i_oldflags;
184
185 if (btrfs_root_readonly(root))
186 return -EROFS;
187
188 if (copy_from_user(&flags, arg, sizeof(flags)))
189 return -EFAULT;
190
191 ret = check_flags(flags);
192 if (ret)
193 return ret;
194
195 if (!inode_owner_or_capable(inode))
196 return -EACCES;
197
198 ret = mnt_want_write_file(file);
199 if (ret)
200 return ret;
201
202 mutex_lock(&inode->i_mutex);
203
204 ip_oldflags = ip->flags;
205 i_oldflags = inode->i_flags;
206
207 flags = btrfs_mask_flags(inode->i_mode, flags);
208 oldflags = btrfs_flags_to_ioctl(ip->flags);
209 if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
210 if (!capable(CAP_LINUX_IMMUTABLE)) {
211 ret = -EPERM;
212 goto out_unlock;
213 }
214 }
215
216 if (flags & FS_SYNC_FL)
217 ip->flags |= BTRFS_INODE_SYNC;
218 else
219 ip->flags &= ~BTRFS_INODE_SYNC;
220 if (flags & FS_IMMUTABLE_FL)
221 ip->flags |= BTRFS_INODE_IMMUTABLE;
222 else
223 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
224 if (flags & FS_APPEND_FL)
225 ip->flags |= BTRFS_INODE_APPEND;
226 else
227 ip->flags &= ~BTRFS_INODE_APPEND;
228 if (flags & FS_NODUMP_FL)
229 ip->flags |= BTRFS_INODE_NODUMP;
230 else
231 ip->flags &= ~BTRFS_INODE_NODUMP;
232 if (flags & FS_NOATIME_FL)
233 ip->flags |= BTRFS_INODE_NOATIME;
234 else
235 ip->flags &= ~BTRFS_INODE_NOATIME;
236 if (flags & FS_DIRSYNC_FL)
237 ip->flags |= BTRFS_INODE_DIRSYNC;
238 else
239 ip->flags &= ~BTRFS_INODE_DIRSYNC;
240 if (flags & FS_NOCOW_FL)
241 ip->flags |= BTRFS_INODE_NODATACOW;
242 else
243 ip->flags &= ~BTRFS_INODE_NODATACOW;
244
245 /*
246 * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
247 * flag may be changed automatically if compression code won't make
248 * things smaller.
249 */
250 if (flags & FS_NOCOMP_FL) {
251 ip->flags &= ~BTRFS_INODE_COMPRESS;
252 ip->flags |= BTRFS_INODE_NOCOMPRESS;
253 } else if (flags & FS_COMPR_FL) {
254 ip->flags |= BTRFS_INODE_COMPRESS;
255 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
256 } else {
257 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
258 }
259
260 trans = btrfs_start_transaction(root, 1);
261 if (IS_ERR(trans)) {
262 ret = PTR_ERR(trans);
263 goto out_drop;
264 }
265
266 btrfs_update_iflags(inode);
267 inode_inc_iversion(inode);
268 inode->i_ctime = CURRENT_TIME;
269 ret = btrfs_update_inode(trans, root, inode);
270
271 btrfs_end_transaction(trans, root);
272 out_drop:
273 if (ret) {
274 ip->flags = ip_oldflags;
275 inode->i_flags = i_oldflags;
276 }
277
278 out_unlock:
279 mutex_unlock(&inode->i_mutex);
280 mnt_drop_write_file(file);
281 return ret;
282 }
283
284 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
285 {
286 struct inode *inode = file->f_path.dentry->d_inode;
287
288 return put_user(inode->i_generation, arg);
289 }
290
291 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
292 {
293 struct btrfs_fs_info *fs_info = btrfs_sb(fdentry(file)->d_sb);
294 struct btrfs_device *device;
295 struct request_queue *q;
296 struct fstrim_range range;
297 u64 minlen = ULLONG_MAX;
298 u64 num_devices = 0;
299 u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
300 int ret;
301
302 if (!capable(CAP_SYS_ADMIN))
303 return -EPERM;
304
305 rcu_read_lock();
306 list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
307 dev_list) {
308 if (!device->bdev)
309 continue;
310 q = bdev_get_queue(device->bdev);
311 if (blk_queue_discard(q)) {
312 num_devices++;
313 minlen = min((u64)q->limits.discard_granularity,
314 minlen);
315 }
316 }
317 rcu_read_unlock();
318
319 if (!num_devices)
320 return -EOPNOTSUPP;
321 if (copy_from_user(&range, arg, sizeof(range)))
322 return -EFAULT;
323 if (range.start > total_bytes)
324 return -EINVAL;
325
326 range.len = min(range.len, total_bytes - range.start);
327 range.minlen = max(range.minlen, minlen);
328 ret = btrfs_trim_fs(fs_info->tree_root, &range);
329 if (ret < 0)
330 return ret;
331
332 if (copy_to_user(arg, &range, sizeof(range)))
333 return -EFAULT;
334
335 return 0;
336 }
337
338 static noinline int create_subvol(struct btrfs_root *root,
339 struct dentry *dentry,
340 char *name, int namelen,
341 u64 *async_transid,
342 struct btrfs_qgroup_inherit **inherit)
343 {
344 struct btrfs_trans_handle *trans;
345 struct btrfs_key key;
346 struct btrfs_root_item root_item;
347 struct btrfs_inode_item *inode_item;
348 struct extent_buffer *leaf;
349 struct btrfs_root *new_root;
350 struct dentry *parent = dentry->d_parent;
351 struct inode *dir;
352 struct timespec cur_time = CURRENT_TIME;
353 int ret;
354 int err;
355 u64 objectid;
356 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
357 u64 index = 0;
358 uuid_le new_uuid;
359
360 ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
361 if (ret)
362 return ret;
363
364 dir = parent->d_inode;
365
366 /*
367 * 1 - inode item
368 * 2 - refs
369 * 1 - root item
370 * 2 - dir items
371 */
372 trans = btrfs_start_transaction(root, 6);
373 if (IS_ERR(trans))
374 return PTR_ERR(trans);
375
376 ret = btrfs_qgroup_inherit(trans, root->fs_info, 0, objectid,
377 inherit ? *inherit : NULL);
378 if (ret)
379 goto fail;
380
381 leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
382 0, objectid, NULL, 0, 0, 0);
383 if (IS_ERR(leaf)) {
384 ret = PTR_ERR(leaf);
385 goto fail;
386 }
387
388 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
389 btrfs_set_header_bytenr(leaf, leaf->start);
390 btrfs_set_header_generation(leaf, trans->transid);
391 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
392 btrfs_set_header_owner(leaf, objectid);
393
394 write_extent_buffer(leaf, root->fs_info->fsid,
395 (unsigned long)btrfs_header_fsid(leaf),
396 BTRFS_FSID_SIZE);
397 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
398 (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
399 BTRFS_UUID_SIZE);
400 btrfs_mark_buffer_dirty(leaf);
401
402 memset(&root_item, 0, sizeof(root_item));
403
404 inode_item = &root_item.inode;
405 inode_item->generation = cpu_to_le64(1);
406 inode_item->size = cpu_to_le64(3);
407 inode_item->nlink = cpu_to_le32(1);
408 inode_item->nbytes = cpu_to_le64(root->leafsize);
409 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
410
411 root_item.flags = 0;
412 root_item.byte_limit = 0;
413 inode_item->flags = cpu_to_le64(BTRFS_INODE_ROOT_ITEM_INIT);
414
415 btrfs_set_root_bytenr(&root_item, leaf->start);
416 btrfs_set_root_generation(&root_item, trans->transid);
417 btrfs_set_root_level(&root_item, 0);
418 btrfs_set_root_refs(&root_item, 1);
419 btrfs_set_root_used(&root_item, leaf->len);
420 btrfs_set_root_last_snapshot(&root_item, 0);
421
422 btrfs_set_root_generation_v2(&root_item,
423 btrfs_root_generation(&root_item));
424 uuid_le_gen(&new_uuid);
425 memcpy(root_item.uuid, new_uuid.b, BTRFS_UUID_SIZE);
426 root_item.otime.sec = cpu_to_le64(cur_time.tv_sec);
427 root_item.otime.nsec = cpu_to_le64(cur_time.tv_nsec);
428 root_item.ctime = root_item.otime;
429 btrfs_set_root_ctransid(&root_item, trans->transid);
430 btrfs_set_root_otransid(&root_item, trans->transid);
431
432 btrfs_tree_unlock(leaf);
433 free_extent_buffer(leaf);
434 leaf = NULL;
435
436 btrfs_set_root_dirid(&root_item, new_dirid);
437
438 key.objectid = objectid;
439 key.offset = 0;
440 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
441 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
442 &root_item);
443 if (ret)
444 goto fail;
445
446 key.offset = (u64)-1;
447 new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
448 if (IS_ERR(new_root)) {
449 btrfs_abort_transaction(trans, root, PTR_ERR(new_root));
450 ret = PTR_ERR(new_root);
451 goto fail;
452 }
453
454 btrfs_record_root_in_trans(trans, new_root);
455
456 ret = btrfs_create_subvol_root(trans, new_root, new_dirid);
457 if (ret) {
458 /* We potentially lose an unused inode item here */
459 btrfs_abort_transaction(trans, root, ret);
460 goto fail;
461 }
462
463 /*
464 * insert the directory item
465 */
466 ret = btrfs_set_inode_index(dir, &index);
467 if (ret) {
468 btrfs_abort_transaction(trans, root, ret);
469 goto fail;
470 }
471
472 ret = btrfs_insert_dir_item(trans, root,
473 name, namelen, dir, &key,
474 BTRFS_FT_DIR, index);
475 if (ret) {
476 btrfs_abort_transaction(trans, root, ret);
477 goto fail;
478 }
479
480 btrfs_i_size_write(dir, dir->i_size + namelen * 2);
481 ret = btrfs_update_inode(trans, root, dir);
482 BUG_ON(ret);
483
484 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
485 objectid, root->root_key.objectid,
486 btrfs_ino(dir), index, name, namelen);
487
488 BUG_ON(ret);
489
490 d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
491 fail:
492 if (async_transid) {
493 *async_transid = trans->transid;
494 err = btrfs_commit_transaction_async(trans, root, 1);
495 } else {
496 err = btrfs_commit_transaction(trans, root);
497 }
498 if (err && !ret)
499 ret = err;
500 return ret;
501 }
502
503 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
504 char *name, int namelen, u64 *async_transid,
505 bool readonly, struct btrfs_qgroup_inherit **inherit)
506 {
507 struct inode *inode;
508 struct btrfs_pending_snapshot *pending_snapshot;
509 struct btrfs_trans_handle *trans;
510 int ret;
511
512 if (!root->ref_cows)
513 return -EINVAL;
514
515 pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
516 if (!pending_snapshot)
517 return -ENOMEM;
518
519 btrfs_init_block_rsv(&pending_snapshot->block_rsv);
520 pending_snapshot->dentry = dentry;
521 pending_snapshot->root = root;
522 pending_snapshot->readonly = readonly;
523 if (inherit) {
524 pending_snapshot->inherit = *inherit;
525 *inherit = NULL; /* take responsibility to free it */
526 }
527
528 trans = btrfs_start_transaction(root->fs_info->extent_root, 5);
529 if (IS_ERR(trans)) {
530 ret = PTR_ERR(trans);
531 goto fail;
532 }
533
534 ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
535 BUG_ON(ret);
536
537 spin_lock(&root->fs_info->trans_lock);
538 list_add(&pending_snapshot->list,
539 &trans->transaction->pending_snapshots);
540 spin_unlock(&root->fs_info->trans_lock);
541 if (async_transid) {
542 *async_transid = trans->transid;
543 ret = btrfs_commit_transaction_async(trans,
544 root->fs_info->extent_root, 1);
545 } else {
546 ret = btrfs_commit_transaction(trans,
547 root->fs_info->extent_root);
548 }
549 BUG_ON(ret);
550
551 ret = pending_snapshot->error;
552 if (ret)
553 goto fail;
554
555 ret = btrfs_orphan_cleanup(pending_snapshot->snap);
556 if (ret)
557 goto fail;
558
559 inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
560 if (IS_ERR(inode)) {
561 ret = PTR_ERR(inode);
562 goto fail;
563 }
564 BUG_ON(!inode);
565 d_instantiate(dentry, inode);
566 ret = 0;
567 fail:
568 kfree(pending_snapshot);
569 return ret;
570 }
571
572 /* copy of check_sticky in fs/namei.c()
573 * It's inline, so penalty for filesystems that don't use sticky bit is
574 * minimal.
575 */
576 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode)
577 {
578 uid_t fsuid = current_fsuid();
579
580 if (!(dir->i_mode & S_ISVTX))
581 return 0;
582 if (inode->i_uid == fsuid)
583 return 0;
584 if (dir->i_uid == fsuid)
585 return 0;
586 return !capable(CAP_FOWNER);
587 }
588
589 /* copy of may_delete in fs/namei.c()
590 * Check whether we can remove a link victim from directory dir, check
591 * whether the type of victim is right.
592 * 1. We can't do it if dir is read-only (done in permission())
593 * 2. We should have write and exec permissions on dir
594 * 3. We can't remove anything from append-only dir
595 * 4. We can't do anything with immutable dir (done in permission())
596 * 5. If the sticky bit on dir is set we should either
597 * a. be owner of dir, or
598 * b. be owner of victim, or
599 * c. have CAP_FOWNER capability
600 * 6. If the victim is append-only or immutable we can't do antyhing with
601 * links pointing to it.
602 * 7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
603 * 8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
604 * 9. We can't remove a root or mountpoint.
605 * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
606 * nfs_async_unlink().
607 */
608
609 static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir)
610 {
611 int error;
612
613 if (!victim->d_inode)
614 return -ENOENT;
615
616 BUG_ON(victim->d_parent->d_inode != dir);
617 audit_inode_child(victim, dir);
618
619 error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
620 if (error)
621 return error;
622 if (IS_APPEND(dir))
623 return -EPERM;
624 if (btrfs_check_sticky(dir, victim->d_inode)||
625 IS_APPEND(victim->d_inode)||
626 IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
627 return -EPERM;
628 if (isdir) {
629 if (!S_ISDIR(victim->d_inode->i_mode))
630 return -ENOTDIR;
631 if (IS_ROOT(victim))
632 return -EBUSY;
633 } else if (S_ISDIR(victim->d_inode->i_mode))
634 return -EISDIR;
635 if (IS_DEADDIR(dir))
636 return -ENOENT;
637 if (victim->d_flags & DCACHE_NFSFS_RENAMED)
638 return -EBUSY;
639 return 0;
640 }
641
642 /* copy of may_create in fs/namei.c() */
643 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
644 {
645 if (child->d_inode)
646 return -EEXIST;
647 if (IS_DEADDIR(dir))
648 return -ENOENT;
649 return inode_permission(dir, MAY_WRITE | MAY_EXEC);
650 }
651
652 /*
653 * Create a new subvolume below @parent. This is largely modeled after
654 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
655 * inside this filesystem so it's quite a bit simpler.
656 */
657 static noinline int btrfs_mksubvol(struct path *parent,
658 char *name, int namelen,
659 struct btrfs_root *snap_src,
660 u64 *async_transid, bool readonly,
661 struct btrfs_qgroup_inherit **inherit)
662 {
663 struct inode *dir = parent->dentry->d_inode;
664 struct dentry *dentry;
665 int error;
666
667 error = mnt_want_write(parent->mnt);
668 if (error)
669 return error;
670
671 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
672
673 dentry = lookup_one_len(name, parent->dentry, namelen);
674 error = PTR_ERR(dentry);
675 if (IS_ERR(dentry))
676 goto out_unlock;
677
678 error = -EEXIST;
679 if (dentry->d_inode)
680 goto out_dput;
681
682 error = btrfs_may_create(dir, dentry);
683 if (error)
684 goto out_dput;
685
686 down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
687
688 if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
689 goto out_up_read;
690
691 if (snap_src) {
692 error = create_snapshot(snap_src, dentry, name, namelen,
693 async_transid, readonly, inherit);
694 } else {
695 error = create_subvol(BTRFS_I(dir)->root, dentry,
696 name, namelen, async_transid, inherit);
697 }
698 if (!error)
699 fsnotify_mkdir(dir, dentry);
700 out_up_read:
701 up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
702 out_dput:
703 dput(dentry);
704 out_unlock:
705 mutex_unlock(&dir->i_mutex);
706 mnt_drop_write(parent->mnt);
707 return error;
708 }
709
710 /*
711 * When we're defragging a range, we don't want to kick it off again
712 * if it is really just waiting for delalloc to send it down.
713 * If we find a nice big extent or delalloc range for the bytes in the
714 * file you want to defrag, we return 0 to let you know to skip this
715 * part of the file
716 */
717 static int check_defrag_in_cache(struct inode *inode, u64 offset, int thresh)
718 {
719 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
720 struct extent_map *em = NULL;
721 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
722 u64 end;
723
724 read_lock(&em_tree->lock);
725 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
726 read_unlock(&em_tree->lock);
727
728 if (em) {
729 end = extent_map_end(em);
730 free_extent_map(em);
731 if (end - offset > thresh)
732 return 0;
733 }
734 /* if we already have a nice delalloc here, just stop */
735 thresh /= 2;
736 end = count_range_bits(io_tree, &offset, offset + thresh,
737 thresh, EXTENT_DELALLOC, 1);
738 if (end >= thresh)
739 return 0;
740 return 1;
741 }
742
743 /*
744 * helper function to walk through a file and find extents
745 * newer than a specific transid, and smaller than thresh.
746 *
747 * This is used by the defragging code to find new and small
748 * extents
749 */
750 static int find_new_extents(struct btrfs_root *root,
751 struct inode *inode, u64 newer_than,
752 u64 *off, int thresh)
753 {
754 struct btrfs_path *path;
755 struct btrfs_key min_key;
756 struct btrfs_key max_key;
757 struct extent_buffer *leaf;
758 struct btrfs_file_extent_item *extent;
759 int type;
760 int ret;
761 u64 ino = btrfs_ino(inode);
762
763 path = btrfs_alloc_path();
764 if (!path)
765 return -ENOMEM;
766
767 min_key.objectid = ino;
768 min_key.type = BTRFS_EXTENT_DATA_KEY;
769 min_key.offset = *off;
770
771 max_key.objectid = ino;
772 max_key.type = (u8)-1;
773 max_key.offset = (u64)-1;
774
775 path->keep_locks = 1;
776
777 while(1) {
778 ret = btrfs_search_forward(root, &min_key, &max_key,
779 path, 0, newer_than);
780 if (ret != 0)
781 goto none;
782 if (min_key.objectid != ino)
783 goto none;
784 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
785 goto none;
786
787 leaf = path->nodes[0];
788 extent = btrfs_item_ptr(leaf, path->slots[0],
789 struct btrfs_file_extent_item);
790
791 type = btrfs_file_extent_type(leaf, extent);
792 if (type == BTRFS_FILE_EXTENT_REG &&
793 btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
794 check_defrag_in_cache(inode, min_key.offset, thresh)) {
795 *off = min_key.offset;
796 btrfs_free_path(path);
797 return 0;
798 }
799
800 if (min_key.offset == (u64)-1)
801 goto none;
802
803 min_key.offset++;
804 btrfs_release_path(path);
805 }
806 none:
807 btrfs_free_path(path);
808 return -ENOENT;
809 }
810
811 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
812 {
813 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
814 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
815 struct extent_map *em;
816 u64 len = PAGE_CACHE_SIZE;
817
818 /*
819 * hopefully we have this extent in the tree already, try without
820 * the full extent lock
821 */
822 read_lock(&em_tree->lock);
823 em = lookup_extent_mapping(em_tree, start, len);
824 read_unlock(&em_tree->lock);
825
826 if (!em) {
827 /* get the big lock and read metadata off disk */
828 lock_extent(io_tree, start, start + len - 1);
829 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
830 unlock_extent(io_tree, start, start + len - 1);
831
832 if (IS_ERR(em))
833 return NULL;
834 }
835
836 return em;
837 }
838
839 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
840 {
841 struct extent_map *next;
842 bool ret = true;
843
844 /* this is the last extent */
845 if (em->start + em->len >= i_size_read(inode))
846 return false;
847
848 next = defrag_lookup_extent(inode, em->start + em->len);
849 if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
850 ret = false;
851
852 free_extent_map(next);
853 return ret;
854 }
855
856 static int should_defrag_range(struct inode *inode, u64 start, int thresh,
857 u64 *last_len, u64 *skip, u64 *defrag_end,
858 int compress)
859 {
860 struct extent_map *em;
861 int ret = 1;
862 bool next_mergeable = true;
863
864 /*
865 * make sure that once we start defragging an extent, we keep on
866 * defragging it
867 */
868 if (start < *defrag_end)
869 return 1;
870
871 *skip = 0;
872
873 em = defrag_lookup_extent(inode, start);
874 if (!em)
875 return 0;
876
877 /* this will cover holes, and inline extents */
878 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
879 ret = 0;
880 goto out;
881 }
882
883 next_mergeable = defrag_check_next_extent(inode, em);
884
885 /*
886 * we hit a real extent, if it is big or the next extent is not a
887 * real extent, don't bother defragging it
888 */
889 if (!compress && (*last_len == 0 || *last_len >= thresh) &&
890 (em->len >= thresh || !next_mergeable))
891 ret = 0;
892 out:
893 /*
894 * last_len ends up being a counter of how many bytes we've defragged.
895 * every time we choose not to defrag an extent, we reset *last_len
896 * so that the next tiny extent will force a defrag.
897 *
898 * The end result of this is that tiny extents before a single big
899 * extent will force at least part of that big extent to be defragged.
900 */
901 if (ret) {
902 *defrag_end = extent_map_end(em);
903 } else {
904 *last_len = 0;
905 *skip = extent_map_end(em);
906 *defrag_end = 0;
907 }
908
909 free_extent_map(em);
910 return ret;
911 }
912
913 /*
914 * it doesn't do much good to defrag one or two pages
915 * at a time. This pulls in a nice chunk of pages
916 * to COW and defrag.
917 *
918 * It also makes sure the delalloc code has enough
919 * dirty data to avoid making new small extents as part
920 * of the defrag
921 *
922 * It's a good idea to start RA on this range
923 * before calling this.
924 */
925 static int cluster_pages_for_defrag(struct inode *inode,
926 struct page **pages,
927 unsigned long start_index,
928 int num_pages)
929 {
930 unsigned long file_end;
931 u64 isize = i_size_read(inode);
932 u64 page_start;
933 u64 page_end;
934 u64 page_cnt;
935 int ret;
936 int i;
937 int i_done;
938 struct btrfs_ordered_extent *ordered;
939 struct extent_state *cached_state = NULL;
940 struct extent_io_tree *tree;
941 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
942
943 file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
944 if (!isize || start_index > file_end)
945 return 0;
946
947 page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
948
949 ret = btrfs_delalloc_reserve_space(inode,
950 page_cnt << PAGE_CACHE_SHIFT);
951 if (ret)
952 return ret;
953 i_done = 0;
954 tree = &BTRFS_I(inode)->io_tree;
955
956 /* step one, lock all the pages */
957 for (i = 0; i < page_cnt; i++) {
958 struct page *page;
959 again:
960 page = find_or_create_page(inode->i_mapping,
961 start_index + i, mask);
962 if (!page)
963 break;
964
965 page_start = page_offset(page);
966 page_end = page_start + PAGE_CACHE_SIZE - 1;
967 while (1) {
968 lock_extent(tree, page_start, page_end);
969 ordered = btrfs_lookup_ordered_extent(inode,
970 page_start);
971 unlock_extent(tree, page_start, page_end);
972 if (!ordered)
973 break;
974
975 unlock_page(page);
976 btrfs_start_ordered_extent(inode, ordered, 1);
977 btrfs_put_ordered_extent(ordered);
978 lock_page(page);
979 /*
980 * we unlocked the page above, so we need check if
981 * it was released or not.
982 */
983 if (page->mapping != inode->i_mapping) {
984 unlock_page(page);
985 page_cache_release(page);
986 goto again;
987 }
988 }
989
990 if (!PageUptodate(page)) {
991 btrfs_readpage(NULL, page);
992 lock_page(page);
993 if (!PageUptodate(page)) {
994 unlock_page(page);
995 page_cache_release(page);
996 ret = -EIO;
997 break;
998 }
999 }
1000
1001 if (page->mapping != inode->i_mapping) {
1002 unlock_page(page);
1003 page_cache_release(page);
1004 goto again;
1005 }
1006
1007 pages[i] = page;
1008 i_done++;
1009 }
1010 if (!i_done || ret)
1011 goto out;
1012
1013 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1014 goto out;
1015
1016 /*
1017 * so now we have a nice long stream of locked
1018 * and up to date pages, lets wait on them
1019 */
1020 for (i = 0; i < i_done; i++)
1021 wait_on_page_writeback(pages[i]);
1022
1023 page_start = page_offset(pages[0]);
1024 page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
1025
1026 lock_extent_bits(&BTRFS_I(inode)->io_tree,
1027 page_start, page_end - 1, 0, &cached_state);
1028 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1029 page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1030 EXTENT_DO_ACCOUNTING, 0, 0, &cached_state,
1031 GFP_NOFS);
1032
1033 if (i_done != page_cnt) {
1034 spin_lock(&BTRFS_I(inode)->lock);
1035 BTRFS_I(inode)->outstanding_extents++;
1036 spin_unlock(&BTRFS_I(inode)->lock);
1037 btrfs_delalloc_release_space(inode,
1038 (page_cnt - i_done) << PAGE_CACHE_SHIFT);
1039 }
1040
1041
1042 btrfs_set_extent_delalloc(inode, page_start, page_end - 1,
1043 &cached_state);
1044
1045 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1046 page_start, page_end - 1, &cached_state,
1047 GFP_NOFS);
1048
1049 for (i = 0; i < i_done; i++) {
1050 clear_page_dirty_for_io(pages[i]);
1051 ClearPageChecked(pages[i]);
1052 set_page_extent_mapped(pages[i]);
1053 set_page_dirty(pages[i]);
1054 unlock_page(pages[i]);
1055 page_cache_release(pages[i]);
1056 }
1057 return i_done;
1058 out:
1059 for (i = 0; i < i_done; i++) {
1060 unlock_page(pages[i]);
1061 page_cache_release(pages[i]);
1062 }
1063 btrfs_delalloc_release_space(inode, page_cnt << PAGE_CACHE_SHIFT);
1064 return ret;
1065
1066 }
1067
1068 int btrfs_defrag_file(struct inode *inode, struct file *file,
1069 struct btrfs_ioctl_defrag_range_args *range,
1070 u64 newer_than, unsigned long max_to_defrag)
1071 {
1072 struct btrfs_root *root = BTRFS_I(inode)->root;
1073 struct file_ra_state *ra = NULL;
1074 unsigned long last_index;
1075 u64 isize = i_size_read(inode);
1076 u64 last_len = 0;
1077 u64 skip = 0;
1078 u64 defrag_end = 0;
1079 u64 newer_off = range->start;
1080 unsigned long i;
1081 unsigned long ra_index = 0;
1082 int ret;
1083 int defrag_count = 0;
1084 int compress_type = BTRFS_COMPRESS_ZLIB;
1085 int extent_thresh = range->extent_thresh;
1086 int max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT;
1087 int cluster = max_cluster;
1088 u64 new_align = ~((u64)128 * 1024 - 1);
1089 struct page **pages = NULL;
1090
1091 if (extent_thresh == 0)
1092 extent_thresh = 256 * 1024;
1093
1094 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1095 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1096 return -EINVAL;
1097 if (range->compress_type)
1098 compress_type = range->compress_type;
1099 }
1100
1101 if (isize == 0)
1102 return 0;
1103
1104 /*
1105 * if we were not given a file, allocate a readahead
1106 * context
1107 */
1108 if (!file) {
1109 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1110 if (!ra)
1111 return -ENOMEM;
1112 file_ra_state_init(ra, inode->i_mapping);
1113 } else {
1114 ra = &file->f_ra;
1115 }
1116
1117 pages = kmalloc(sizeof(struct page *) * max_cluster,
1118 GFP_NOFS);
1119 if (!pages) {
1120 ret = -ENOMEM;
1121 goto out_ra;
1122 }
1123
1124 /* find the last page to defrag */
1125 if (range->start + range->len > range->start) {
1126 last_index = min_t(u64, isize - 1,
1127 range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
1128 } else {
1129 last_index = (isize - 1) >> PAGE_CACHE_SHIFT;
1130 }
1131
1132 if (newer_than) {
1133 ret = find_new_extents(root, inode, newer_than,
1134 &newer_off, 64 * 1024);
1135 if (!ret) {
1136 range->start = newer_off;
1137 /*
1138 * we always align our defrag to help keep
1139 * the extents in the file evenly spaced
1140 */
1141 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1142 } else
1143 goto out_ra;
1144 } else {
1145 i = range->start >> PAGE_CACHE_SHIFT;
1146 }
1147 if (!max_to_defrag)
1148 max_to_defrag = last_index + 1;
1149
1150 /*
1151 * make writeback starts from i, so the defrag range can be
1152 * written sequentially.
1153 */
1154 if (i < inode->i_mapping->writeback_index)
1155 inode->i_mapping->writeback_index = i;
1156
1157 while (i <= last_index && defrag_count < max_to_defrag &&
1158 (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1159 PAGE_CACHE_SHIFT)) {
1160 /*
1161 * make sure we stop running if someone unmounts
1162 * the FS
1163 */
1164 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1165 break;
1166
1167 if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
1168 extent_thresh, &last_len, &skip,
1169 &defrag_end, range->flags &
1170 BTRFS_DEFRAG_RANGE_COMPRESS)) {
1171 unsigned long next;
1172 /*
1173 * the should_defrag function tells us how much to skip
1174 * bump our counter by the suggested amount
1175 */
1176 next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1177 i = max(i + 1, next);
1178 continue;
1179 }
1180
1181 if (!newer_than) {
1182 cluster = (PAGE_CACHE_ALIGN(defrag_end) >>
1183 PAGE_CACHE_SHIFT) - i;
1184 cluster = min(cluster, max_cluster);
1185 } else {
1186 cluster = max_cluster;
1187 }
1188
1189 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1190 BTRFS_I(inode)->force_compress = compress_type;
1191
1192 if (i + cluster > ra_index) {
1193 ra_index = max(i, ra_index);
1194 btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1195 cluster);
1196 ra_index += max_cluster;
1197 }
1198
1199 mutex_lock(&inode->i_mutex);
1200 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1201 if (ret < 0) {
1202 mutex_unlock(&inode->i_mutex);
1203 goto out_ra;
1204 }
1205
1206 defrag_count += ret;
1207 balance_dirty_pages_ratelimited_nr(inode->i_mapping, ret);
1208 mutex_unlock(&inode->i_mutex);
1209
1210 if (newer_than) {
1211 if (newer_off == (u64)-1)
1212 break;
1213
1214 if (ret > 0)
1215 i += ret;
1216
1217 newer_off = max(newer_off + 1,
1218 (u64)i << PAGE_CACHE_SHIFT);
1219
1220 ret = find_new_extents(root, inode,
1221 newer_than, &newer_off,
1222 64 * 1024);
1223 if (!ret) {
1224 range->start = newer_off;
1225 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1226 } else {
1227 break;
1228 }
1229 } else {
1230 if (ret > 0) {
1231 i += ret;
1232 last_len += ret << PAGE_CACHE_SHIFT;
1233 } else {
1234 i++;
1235 last_len = 0;
1236 }
1237 }
1238 }
1239
1240 if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
1241 filemap_flush(inode->i_mapping);
1242
1243 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1244 /* the filemap_flush will queue IO into the worker threads, but
1245 * we have to make sure the IO is actually started and that
1246 * ordered extents get created before we return
1247 */
1248 atomic_inc(&root->fs_info->async_submit_draining);
1249 while (atomic_read(&root->fs_info->nr_async_submits) ||
1250 atomic_read(&root->fs_info->async_delalloc_pages)) {
1251 wait_event(root->fs_info->async_submit_wait,
1252 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1253 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1254 }
1255 atomic_dec(&root->fs_info->async_submit_draining);
1256
1257 mutex_lock(&inode->i_mutex);
1258 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1259 mutex_unlock(&inode->i_mutex);
1260 }
1261
1262 if (range->compress_type == BTRFS_COMPRESS_LZO) {
1263 btrfs_set_fs_incompat(root->fs_info, COMPRESS_LZO);
1264 }
1265
1266 ret = defrag_count;
1267
1268 out_ra:
1269 if (!file)
1270 kfree(ra);
1271 kfree(pages);
1272 return ret;
1273 }
1274
1275 static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
1276 void __user *arg)
1277 {
1278 u64 new_size;
1279 u64 old_size;
1280 u64 devid = 1;
1281 struct btrfs_ioctl_vol_args *vol_args;
1282 struct btrfs_trans_handle *trans;
1283 struct btrfs_device *device = NULL;
1284 char *sizestr;
1285 char *devstr = NULL;
1286 int ret = 0;
1287 int mod = 0;
1288
1289 if (root->fs_info->sb->s_flags & MS_RDONLY)
1290 return -EROFS;
1291
1292 if (!capable(CAP_SYS_ADMIN))
1293 return -EPERM;
1294
1295 mutex_lock(&root->fs_info->volume_mutex);
1296 if (root->fs_info->balance_ctl) {
1297 printk(KERN_INFO "btrfs: balance in progress\n");
1298 ret = -EINVAL;
1299 goto out;
1300 }
1301
1302 vol_args = memdup_user(arg, sizeof(*vol_args));
1303 if (IS_ERR(vol_args)) {
1304 ret = PTR_ERR(vol_args);
1305 goto out;
1306 }
1307
1308 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1309
1310 sizestr = vol_args->name;
1311 devstr = strchr(sizestr, ':');
1312 if (devstr) {
1313 char *end;
1314 sizestr = devstr + 1;
1315 *devstr = '\0';
1316 devstr = vol_args->name;
1317 devid = simple_strtoull(devstr, &end, 10);
1318 printk(KERN_INFO "btrfs: resizing devid %llu\n",
1319 (unsigned long long)devid);
1320 }
1321 device = btrfs_find_device(root, devid, NULL, NULL);
1322 if (!device) {
1323 printk(KERN_INFO "btrfs: resizer unable to find device %llu\n",
1324 (unsigned long long)devid);
1325 ret = -EINVAL;
1326 goto out_free;
1327 }
1328 if (device->fs_devices && device->fs_devices->seeding) {
1329 printk(KERN_INFO "btrfs: resizer unable to apply on "
1330 "seeding device %llu\n",
1331 (unsigned long long)devid);
1332 ret = -EINVAL;
1333 goto out_free;
1334 }
1335
1336 if (!strcmp(sizestr, "max"))
1337 new_size = device->bdev->bd_inode->i_size;
1338 else {
1339 if (sizestr[0] == '-') {
1340 mod = -1;
1341 sizestr++;
1342 } else if (sizestr[0] == '+') {
1343 mod = 1;
1344 sizestr++;
1345 }
1346 new_size = memparse(sizestr, NULL);
1347 if (new_size == 0) {
1348 ret = -EINVAL;
1349 goto out_free;
1350 }
1351 }
1352
1353 old_size = device->total_bytes;
1354
1355 if (mod < 0) {
1356 if (new_size > old_size) {
1357 ret = -EINVAL;
1358 goto out_free;
1359 }
1360 new_size = old_size - new_size;
1361 } else if (mod > 0) {
1362 new_size = old_size + new_size;
1363 }
1364
1365 if (new_size < 256 * 1024 * 1024) {
1366 ret = -EINVAL;
1367 goto out_free;
1368 }
1369 if (new_size > device->bdev->bd_inode->i_size) {
1370 ret = -EFBIG;
1371 goto out_free;
1372 }
1373
1374 do_div(new_size, root->sectorsize);
1375 new_size *= root->sectorsize;
1376
1377 printk_in_rcu(KERN_INFO "btrfs: new size for %s is %llu\n",
1378 rcu_str_deref(device->name),
1379 (unsigned long long)new_size);
1380
1381 if (new_size > old_size) {
1382 trans = btrfs_start_transaction(root, 0);
1383 if (IS_ERR(trans)) {
1384 ret = PTR_ERR(trans);
1385 goto out_free;
1386 }
1387 ret = btrfs_grow_device(trans, device, new_size);
1388 btrfs_commit_transaction(trans, root);
1389 } else if (new_size < old_size) {
1390 ret = btrfs_shrink_device(device, new_size);
1391 }
1392
1393 out_free:
1394 kfree(vol_args);
1395 out:
1396 mutex_unlock(&root->fs_info->volume_mutex);
1397 return ret;
1398 }
1399
1400 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1401 char *name, unsigned long fd, int subvol,
1402 u64 *transid, bool readonly,
1403 struct btrfs_qgroup_inherit **inherit)
1404 {
1405 struct file *src_file;
1406 int namelen;
1407 int ret = 0;
1408
1409 ret = mnt_want_write_file(file);
1410 if (ret)
1411 goto out;
1412
1413 namelen = strlen(name);
1414 if (strchr(name, '/')) {
1415 ret = -EINVAL;
1416 goto out_drop_write;
1417 }
1418
1419 if (name[0] == '.' &&
1420 (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1421 ret = -EEXIST;
1422 goto out_drop_write;
1423 }
1424
1425 if (subvol) {
1426 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1427 NULL, transid, readonly, inherit);
1428 } else {
1429 struct inode *src_inode;
1430 src_file = fget(fd);
1431 if (!src_file) {
1432 ret = -EINVAL;
1433 goto out_drop_write;
1434 }
1435
1436 src_inode = src_file->f_path.dentry->d_inode;
1437 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
1438 printk(KERN_INFO "btrfs: Snapshot src from "
1439 "another FS\n");
1440 ret = -EINVAL;
1441 fput(src_file);
1442 goto out_drop_write;
1443 }
1444 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1445 BTRFS_I(src_inode)->root,
1446 transid, readonly, inherit);
1447 fput(src_file);
1448 }
1449 out_drop_write:
1450 mnt_drop_write_file(file);
1451 out:
1452 return ret;
1453 }
1454
1455 static noinline int btrfs_ioctl_snap_create(struct file *file,
1456 void __user *arg, int subvol)
1457 {
1458 struct btrfs_ioctl_vol_args *vol_args;
1459 int ret;
1460
1461 vol_args = memdup_user(arg, sizeof(*vol_args));
1462 if (IS_ERR(vol_args))
1463 return PTR_ERR(vol_args);
1464 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1465
1466 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1467 vol_args->fd, subvol,
1468 NULL, false, NULL);
1469
1470 kfree(vol_args);
1471 return ret;
1472 }
1473
1474 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1475 void __user *arg, int subvol)
1476 {
1477 struct btrfs_ioctl_vol_args_v2 *vol_args;
1478 int ret;
1479 u64 transid = 0;
1480 u64 *ptr = NULL;
1481 bool readonly = false;
1482 struct btrfs_qgroup_inherit *inherit = NULL;
1483
1484 vol_args = memdup_user(arg, sizeof(*vol_args));
1485 if (IS_ERR(vol_args))
1486 return PTR_ERR(vol_args);
1487 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1488
1489 if (vol_args->flags &
1490 ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1491 BTRFS_SUBVOL_QGROUP_INHERIT)) {
1492 ret = -EOPNOTSUPP;
1493 goto out;
1494 }
1495
1496 if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1497 ptr = &transid;
1498 if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1499 readonly = true;
1500 if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1501 if (vol_args->size > PAGE_CACHE_SIZE) {
1502 ret = -EINVAL;
1503 goto out;
1504 }
1505 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1506 if (IS_ERR(inherit)) {
1507 ret = PTR_ERR(inherit);
1508 goto out;
1509 }
1510 }
1511
1512 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1513 vol_args->fd, subvol, ptr,
1514 readonly, &inherit);
1515
1516 if (ret == 0 && ptr &&
1517 copy_to_user(arg +
1518 offsetof(struct btrfs_ioctl_vol_args_v2,
1519 transid), ptr, sizeof(*ptr)))
1520 ret = -EFAULT;
1521 out:
1522 kfree(vol_args);
1523 kfree(inherit);
1524 return ret;
1525 }
1526
1527 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1528 void __user *arg)
1529 {
1530 struct inode *inode = fdentry(file)->d_inode;
1531 struct btrfs_root *root = BTRFS_I(inode)->root;
1532 int ret = 0;
1533 u64 flags = 0;
1534
1535 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1536 return -EINVAL;
1537
1538 down_read(&root->fs_info->subvol_sem);
1539 if (btrfs_root_readonly(root))
1540 flags |= BTRFS_SUBVOL_RDONLY;
1541 up_read(&root->fs_info->subvol_sem);
1542
1543 if (copy_to_user(arg, &flags, sizeof(flags)))
1544 ret = -EFAULT;
1545
1546 return ret;
1547 }
1548
1549 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1550 void __user *arg)
1551 {
1552 struct inode *inode = fdentry(file)->d_inode;
1553 struct btrfs_root *root = BTRFS_I(inode)->root;
1554 struct btrfs_trans_handle *trans;
1555 u64 root_flags;
1556 u64 flags;
1557 int ret = 0;
1558
1559 ret = mnt_want_write_file(file);
1560 if (ret)
1561 goto out;
1562
1563 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1564 ret = -EINVAL;
1565 goto out_drop_write;
1566 }
1567
1568 if (copy_from_user(&flags, arg, sizeof(flags))) {
1569 ret = -EFAULT;
1570 goto out_drop_write;
1571 }
1572
1573 if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1574 ret = -EINVAL;
1575 goto out_drop_write;
1576 }
1577
1578 if (flags & ~BTRFS_SUBVOL_RDONLY) {
1579 ret = -EOPNOTSUPP;
1580 goto out_drop_write;
1581 }
1582
1583 if (!inode_owner_or_capable(inode)) {
1584 ret = -EACCES;
1585 goto out_drop_write;
1586 }
1587
1588 down_write(&root->fs_info->subvol_sem);
1589
1590 /* nothing to do */
1591 if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1592 goto out_drop_sem;
1593
1594 root_flags = btrfs_root_flags(&root->root_item);
1595 if (flags & BTRFS_SUBVOL_RDONLY)
1596 btrfs_set_root_flags(&root->root_item,
1597 root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1598 else
1599 btrfs_set_root_flags(&root->root_item,
1600 root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1601
1602 trans = btrfs_start_transaction(root, 1);
1603 if (IS_ERR(trans)) {
1604 ret = PTR_ERR(trans);
1605 goto out_reset;
1606 }
1607
1608 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1609 &root->root_key, &root->root_item);
1610
1611 btrfs_commit_transaction(trans, root);
1612 out_reset:
1613 if (ret)
1614 btrfs_set_root_flags(&root->root_item, root_flags);
1615 out_drop_sem:
1616 up_write(&root->fs_info->subvol_sem);
1617 out_drop_write:
1618 mnt_drop_write_file(file);
1619 out:
1620 return ret;
1621 }
1622
1623 /*
1624 * helper to check if the subvolume references other subvolumes
1625 */
1626 static noinline int may_destroy_subvol(struct btrfs_root *root)
1627 {
1628 struct btrfs_path *path;
1629 struct btrfs_key key;
1630 int ret;
1631
1632 path = btrfs_alloc_path();
1633 if (!path)
1634 return -ENOMEM;
1635
1636 key.objectid = root->root_key.objectid;
1637 key.type = BTRFS_ROOT_REF_KEY;
1638 key.offset = (u64)-1;
1639
1640 ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1641 &key, path, 0, 0);
1642 if (ret < 0)
1643 goto out;
1644 BUG_ON(ret == 0);
1645
1646 ret = 0;
1647 if (path->slots[0] > 0) {
1648 path->slots[0]--;
1649 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1650 if (key.objectid == root->root_key.objectid &&
1651 key.type == BTRFS_ROOT_REF_KEY)
1652 ret = -ENOTEMPTY;
1653 }
1654 out:
1655 btrfs_free_path(path);
1656 return ret;
1657 }
1658
1659 static noinline int key_in_sk(struct btrfs_key *key,
1660 struct btrfs_ioctl_search_key *sk)
1661 {
1662 struct btrfs_key test;
1663 int ret;
1664
1665 test.objectid = sk->min_objectid;
1666 test.type = sk->min_type;
1667 test.offset = sk->min_offset;
1668
1669 ret = btrfs_comp_cpu_keys(key, &test);
1670 if (ret < 0)
1671 return 0;
1672
1673 test.objectid = sk->max_objectid;
1674 test.type = sk->max_type;
1675 test.offset = sk->max_offset;
1676
1677 ret = btrfs_comp_cpu_keys(key, &test);
1678 if (ret > 0)
1679 return 0;
1680 return 1;
1681 }
1682
1683 static noinline int copy_to_sk(struct btrfs_root *root,
1684 struct btrfs_path *path,
1685 struct btrfs_key *key,
1686 struct btrfs_ioctl_search_key *sk,
1687 char *buf,
1688 unsigned long *sk_offset,
1689 int *num_found)
1690 {
1691 u64 found_transid;
1692 struct extent_buffer *leaf;
1693 struct btrfs_ioctl_search_header sh;
1694 unsigned long item_off;
1695 unsigned long item_len;
1696 int nritems;
1697 int i;
1698 int slot;
1699 int ret = 0;
1700
1701 leaf = path->nodes[0];
1702 slot = path->slots[0];
1703 nritems = btrfs_header_nritems(leaf);
1704
1705 if (btrfs_header_generation(leaf) > sk->max_transid) {
1706 i = nritems;
1707 goto advance_key;
1708 }
1709 found_transid = btrfs_header_generation(leaf);
1710
1711 for (i = slot; i < nritems; i++) {
1712 item_off = btrfs_item_ptr_offset(leaf, i);
1713 item_len = btrfs_item_size_nr(leaf, i);
1714
1715 if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1716 item_len = 0;
1717
1718 if (sizeof(sh) + item_len + *sk_offset >
1719 BTRFS_SEARCH_ARGS_BUFSIZE) {
1720 ret = 1;
1721 goto overflow;
1722 }
1723
1724 btrfs_item_key_to_cpu(leaf, key, i);
1725 if (!key_in_sk(key, sk))
1726 continue;
1727
1728 sh.objectid = key->objectid;
1729 sh.offset = key->offset;
1730 sh.type = key->type;
1731 sh.len = item_len;
1732 sh.transid = found_transid;
1733
1734 /* copy search result header */
1735 memcpy(buf + *sk_offset, &sh, sizeof(sh));
1736 *sk_offset += sizeof(sh);
1737
1738 if (item_len) {
1739 char *p = buf + *sk_offset;
1740 /* copy the item */
1741 read_extent_buffer(leaf, p,
1742 item_off, item_len);
1743 *sk_offset += item_len;
1744 }
1745 (*num_found)++;
1746
1747 if (*num_found >= sk->nr_items)
1748 break;
1749 }
1750 advance_key:
1751 ret = 0;
1752 if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1753 key->offset++;
1754 else if (key->type < (u8)-1 && key->type < sk->max_type) {
1755 key->offset = 0;
1756 key->type++;
1757 } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1758 key->offset = 0;
1759 key->type = 0;
1760 key->objectid++;
1761 } else
1762 ret = 1;
1763 overflow:
1764 return ret;
1765 }
1766
1767 static noinline int search_ioctl(struct inode *inode,
1768 struct btrfs_ioctl_search_args *args)
1769 {
1770 struct btrfs_root *root;
1771 struct btrfs_key key;
1772 struct btrfs_key max_key;
1773 struct btrfs_path *path;
1774 struct btrfs_ioctl_search_key *sk = &args->key;
1775 struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1776 int ret;
1777 int num_found = 0;
1778 unsigned long sk_offset = 0;
1779
1780 path = btrfs_alloc_path();
1781 if (!path)
1782 return -ENOMEM;
1783
1784 if (sk->tree_id == 0) {
1785 /* search the root of the inode that was passed */
1786 root = BTRFS_I(inode)->root;
1787 } else {
1788 key.objectid = sk->tree_id;
1789 key.type = BTRFS_ROOT_ITEM_KEY;
1790 key.offset = (u64)-1;
1791 root = btrfs_read_fs_root_no_name(info, &key);
1792 if (IS_ERR(root)) {
1793 printk(KERN_ERR "could not find root %llu\n",
1794 sk->tree_id);
1795 btrfs_free_path(path);
1796 return -ENOENT;
1797 }
1798 }
1799
1800 key.objectid = sk->min_objectid;
1801 key.type = sk->min_type;
1802 key.offset = sk->min_offset;
1803
1804 max_key.objectid = sk->max_objectid;
1805 max_key.type = sk->max_type;
1806 max_key.offset = sk->max_offset;
1807
1808 path->keep_locks = 1;
1809
1810 while(1) {
1811 ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1812 sk->min_transid);
1813 if (ret != 0) {
1814 if (ret > 0)
1815 ret = 0;
1816 goto err;
1817 }
1818 ret = copy_to_sk(root, path, &key, sk, args->buf,
1819 &sk_offset, &num_found);
1820 btrfs_release_path(path);
1821 if (ret || num_found >= sk->nr_items)
1822 break;
1823
1824 }
1825 ret = 0;
1826 err:
1827 sk->nr_items = num_found;
1828 btrfs_free_path(path);
1829 return ret;
1830 }
1831
1832 static noinline int btrfs_ioctl_tree_search(struct file *file,
1833 void __user *argp)
1834 {
1835 struct btrfs_ioctl_search_args *args;
1836 struct inode *inode;
1837 int ret;
1838
1839 if (!capable(CAP_SYS_ADMIN))
1840 return -EPERM;
1841
1842 args = memdup_user(argp, sizeof(*args));
1843 if (IS_ERR(args))
1844 return PTR_ERR(args);
1845
1846 inode = fdentry(file)->d_inode;
1847 ret = search_ioctl(inode, args);
1848 if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1849 ret = -EFAULT;
1850 kfree(args);
1851 return ret;
1852 }
1853
1854 /*
1855 * Search INODE_REFs to identify path name of 'dirid' directory
1856 * in a 'tree_id' tree. and sets path name to 'name'.
1857 */
1858 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1859 u64 tree_id, u64 dirid, char *name)
1860 {
1861 struct btrfs_root *root;
1862 struct btrfs_key key;
1863 char *ptr;
1864 int ret = -1;
1865 int slot;
1866 int len;
1867 int total_len = 0;
1868 struct btrfs_inode_ref *iref;
1869 struct extent_buffer *l;
1870 struct btrfs_path *path;
1871
1872 if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1873 name[0]='\0';
1874 return 0;
1875 }
1876
1877 path = btrfs_alloc_path();
1878 if (!path)
1879 return -ENOMEM;
1880
1881 ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1882
1883 key.objectid = tree_id;
1884 key.type = BTRFS_ROOT_ITEM_KEY;
1885 key.offset = (u64)-1;
1886 root = btrfs_read_fs_root_no_name(info, &key);
1887 if (IS_ERR(root)) {
1888 printk(KERN_ERR "could not find root %llu\n", tree_id);
1889 ret = -ENOENT;
1890 goto out;
1891 }
1892
1893 key.objectid = dirid;
1894 key.type = BTRFS_INODE_REF_KEY;
1895 key.offset = (u64)-1;
1896
1897 while(1) {
1898 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1899 if (ret < 0)
1900 goto out;
1901
1902 l = path->nodes[0];
1903 slot = path->slots[0];
1904 if (ret > 0 && slot > 0)
1905 slot--;
1906 btrfs_item_key_to_cpu(l, &key, slot);
1907
1908 if (ret > 0 && (key.objectid != dirid ||
1909 key.type != BTRFS_INODE_REF_KEY)) {
1910 ret = -ENOENT;
1911 goto out;
1912 }
1913
1914 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1915 len = btrfs_inode_ref_name_len(l, iref);
1916 ptr -= len + 1;
1917 total_len += len + 1;
1918 if (ptr < name)
1919 goto out;
1920
1921 *(ptr + len) = '/';
1922 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1923
1924 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1925 break;
1926
1927 btrfs_release_path(path);
1928 key.objectid = key.offset;
1929 key.offset = (u64)-1;
1930 dirid = key.objectid;
1931 }
1932 if (ptr < name)
1933 goto out;
1934 memmove(name, ptr, total_len);
1935 name[total_len]='\0';
1936 ret = 0;
1937 out:
1938 btrfs_free_path(path);
1939 return ret;
1940 }
1941
1942 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1943 void __user *argp)
1944 {
1945 struct btrfs_ioctl_ino_lookup_args *args;
1946 struct inode *inode;
1947 int ret;
1948
1949 if (!capable(CAP_SYS_ADMIN))
1950 return -EPERM;
1951
1952 args = memdup_user(argp, sizeof(*args));
1953 if (IS_ERR(args))
1954 return PTR_ERR(args);
1955
1956 inode = fdentry(file)->d_inode;
1957
1958 if (args->treeid == 0)
1959 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
1960
1961 ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
1962 args->treeid, args->objectid,
1963 args->name);
1964
1965 if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1966 ret = -EFAULT;
1967
1968 kfree(args);
1969 return ret;
1970 }
1971
1972 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
1973 void __user *arg)
1974 {
1975 struct dentry *parent = fdentry(file);
1976 struct dentry *dentry;
1977 struct inode *dir = parent->d_inode;
1978 struct inode *inode;
1979 struct btrfs_root *root = BTRFS_I(dir)->root;
1980 struct btrfs_root *dest = NULL;
1981 struct btrfs_ioctl_vol_args *vol_args;
1982 struct btrfs_trans_handle *trans;
1983 int namelen;
1984 int ret;
1985 int err = 0;
1986
1987 vol_args = memdup_user(arg, sizeof(*vol_args));
1988 if (IS_ERR(vol_args))
1989 return PTR_ERR(vol_args);
1990
1991 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1992 namelen = strlen(vol_args->name);
1993 if (strchr(vol_args->name, '/') ||
1994 strncmp(vol_args->name, "..", namelen) == 0) {
1995 err = -EINVAL;
1996 goto out;
1997 }
1998
1999 err = mnt_want_write_file(file);
2000 if (err)
2001 goto out;
2002
2003 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
2004 dentry = lookup_one_len(vol_args->name, parent, namelen);
2005 if (IS_ERR(dentry)) {
2006 err = PTR_ERR(dentry);
2007 goto out_unlock_dir;
2008 }
2009
2010 if (!dentry->d_inode) {
2011 err = -ENOENT;
2012 goto out_dput;
2013 }
2014
2015 inode = dentry->d_inode;
2016 dest = BTRFS_I(inode)->root;
2017 if (!capable(CAP_SYS_ADMIN)){
2018 /*
2019 * Regular user. Only allow this with a special mount
2020 * option, when the user has write+exec access to the
2021 * subvol root, and when rmdir(2) would have been
2022 * allowed.
2023 *
2024 * Note that this is _not_ check that the subvol is
2025 * empty or doesn't contain data that we wouldn't
2026 * otherwise be able to delete.
2027 *
2028 * Users who want to delete empty subvols should try
2029 * rmdir(2).
2030 */
2031 err = -EPERM;
2032 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
2033 goto out_dput;
2034
2035 /*
2036 * Do not allow deletion if the parent dir is the same
2037 * as the dir to be deleted. That means the ioctl
2038 * must be called on the dentry referencing the root
2039 * of the subvol, not a random directory contained
2040 * within it.
2041 */
2042 err = -EINVAL;
2043 if (root == dest)
2044 goto out_dput;
2045
2046 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2047 if (err)
2048 goto out_dput;
2049
2050 /* check if subvolume may be deleted by a non-root user */
2051 err = btrfs_may_delete(dir, dentry, 1);
2052 if (err)
2053 goto out_dput;
2054 }
2055
2056 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
2057 err = -EINVAL;
2058 goto out_dput;
2059 }
2060
2061 mutex_lock(&inode->i_mutex);
2062 err = d_invalidate(dentry);
2063 if (err)
2064 goto out_unlock;
2065
2066 down_write(&root->fs_info->subvol_sem);
2067
2068 err = may_destroy_subvol(dest);
2069 if (err)
2070 goto out_up_write;
2071
2072 trans = btrfs_start_transaction(root, 0);
2073 if (IS_ERR(trans)) {
2074 err = PTR_ERR(trans);
2075 goto out_up_write;
2076 }
2077 trans->block_rsv = &root->fs_info->global_block_rsv;
2078
2079 ret = btrfs_unlink_subvol(trans, root, dir,
2080 dest->root_key.objectid,
2081 dentry->d_name.name,
2082 dentry->d_name.len);
2083 if (ret) {
2084 err = ret;
2085 btrfs_abort_transaction(trans, root, ret);
2086 goto out_end_trans;
2087 }
2088
2089 btrfs_record_root_in_trans(trans, dest);
2090
2091 memset(&dest->root_item.drop_progress, 0,
2092 sizeof(dest->root_item.drop_progress));
2093 dest->root_item.drop_level = 0;
2094 btrfs_set_root_refs(&dest->root_item, 0);
2095
2096 if (!xchg(&dest->orphan_item_inserted, 1)) {
2097 ret = btrfs_insert_orphan_item(trans,
2098 root->fs_info->tree_root,
2099 dest->root_key.objectid);
2100 if (ret) {
2101 btrfs_abort_transaction(trans, root, ret);
2102 err = ret;
2103 goto out_end_trans;
2104 }
2105 }
2106 out_end_trans:
2107 ret = btrfs_end_transaction(trans, root);
2108 if (ret && !err)
2109 err = ret;
2110 inode->i_flags |= S_DEAD;
2111 out_up_write:
2112 up_write(&root->fs_info->subvol_sem);
2113 out_unlock:
2114 mutex_unlock(&inode->i_mutex);
2115 if (!err) {
2116 shrink_dcache_sb(root->fs_info->sb);
2117 btrfs_invalidate_inodes(dest);
2118 d_delete(dentry);
2119 }
2120 out_dput:
2121 dput(dentry);
2122 out_unlock_dir:
2123 mutex_unlock(&dir->i_mutex);
2124 mnt_drop_write_file(file);
2125 out:
2126 kfree(vol_args);
2127 return err;
2128 }
2129
2130 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2131 {
2132 struct inode *inode = fdentry(file)->d_inode;
2133 struct btrfs_root *root = BTRFS_I(inode)->root;
2134 struct btrfs_ioctl_defrag_range_args *range;
2135 int ret;
2136
2137 if (btrfs_root_readonly(root))
2138 return -EROFS;
2139
2140 ret = mnt_want_write_file(file);
2141 if (ret)
2142 return ret;
2143
2144 switch (inode->i_mode & S_IFMT) {
2145 case S_IFDIR:
2146 if (!capable(CAP_SYS_ADMIN)) {
2147 ret = -EPERM;
2148 goto out;
2149 }
2150 ret = btrfs_defrag_root(root, 0);
2151 if (ret)
2152 goto out;
2153 ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
2154 break;
2155 case S_IFREG:
2156 if (!(file->f_mode & FMODE_WRITE)) {
2157 ret = -EINVAL;
2158 goto out;
2159 }
2160
2161 range = kzalloc(sizeof(*range), GFP_KERNEL);
2162 if (!range) {
2163 ret = -ENOMEM;
2164 goto out;
2165 }
2166
2167 if (argp) {
2168 if (copy_from_user(range, argp,
2169 sizeof(*range))) {
2170 ret = -EFAULT;
2171 kfree(range);
2172 goto out;
2173 }
2174 /* compression requires us to start the IO */
2175 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2176 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2177 range->extent_thresh = (u32)-1;
2178 }
2179 } else {
2180 /* the rest are all set to zero by kzalloc */
2181 range->len = (u64)-1;
2182 }
2183 ret = btrfs_defrag_file(fdentry(file)->d_inode, file,
2184 range, 0, 0);
2185 if (ret > 0)
2186 ret = 0;
2187 kfree(range);
2188 break;
2189 default:
2190 ret = -EINVAL;
2191 }
2192 out:
2193 mnt_drop_write_file(file);
2194 return ret;
2195 }
2196
2197 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2198 {
2199 struct btrfs_ioctl_vol_args *vol_args;
2200 int ret;
2201
2202 if (!capable(CAP_SYS_ADMIN))
2203 return -EPERM;
2204
2205 mutex_lock(&root->fs_info->volume_mutex);
2206 if (root->fs_info->balance_ctl) {
2207 printk(KERN_INFO "btrfs: balance in progress\n");
2208 ret = -EINVAL;
2209 goto out;
2210 }
2211
2212 vol_args = memdup_user(arg, sizeof(*vol_args));
2213 if (IS_ERR(vol_args)) {
2214 ret = PTR_ERR(vol_args);
2215 goto out;
2216 }
2217
2218 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2219 ret = btrfs_init_new_device(root, vol_args->name);
2220
2221 kfree(vol_args);
2222 out:
2223 mutex_unlock(&root->fs_info->volume_mutex);
2224 return ret;
2225 }
2226
2227 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
2228 {
2229 struct btrfs_ioctl_vol_args *vol_args;
2230 int ret;
2231
2232 if (!capable(CAP_SYS_ADMIN))
2233 return -EPERM;
2234
2235 if (root->fs_info->sb->s_flags & MS_RDONLY)
2236 return -EROFS;
2237
2238 mutex_lock(&root->fs_info->volume_mutex);
2239 if (root->fs_info->balance_ctl) {
2240 printk(KERN_INFO "btrfs: balance in progress\n");
2241 ret = -EINVAL;
2242 goto out;
2243 }
2244
2245 vol_args = memdup_user(arg, sizeof(*vol_args));
2246 if (IS_ERR(vol_args)) {
2247 ret = PTR_ERR(vol_args);
2248 goto out;
2249 }
2250
2251 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2252 ret = btrfs_rm_device(root, vol_args->name);
2253
2254 kfree(vol_args);
2255 out:
2256 mutex_unlock(&root->fs_info->volume_mutex);
2257 return ret;
2258 }
2259
2260 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2261 {
2262 struct btrfs_ioctl_fs_info_args *fi_args;
2263 struct btrfs_device *device;
2264 struct btrfs_device *next;
2265 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2266 int ret = 0;
2267
2268 if (!capable(CAP_SYS_ADMIN))
2269 return -EPERM;
2270
2271 fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2272 if (!fi_args)
2273 return -ENOMEM;
2274
2275 fi_args->num_devices = fs_devices->num_devices;
2276 memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2277
2278 mutex_lock(&fs_devices->device_list_mutex);
2279 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
2280 if (device->devid > fi_args->max_id)
2281 fi_args->max_id = device->devid;
2282 }
2283 mutex_unlock(&fs_devices->device_list_mutex);
2284
2285 if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2286 ret = -EFAULT;
2287
2288 kfree(fi_args);
2289 return ret;
2290 }
2291
2292 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2293 {
2294 struct btrfs_ioctl_dev_info_args *di_args;
2295 struct btrfs_device *dev;
2296 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2297 int ret = 0;
2298 char *s_uuid = NULL;
2299 char empty_uuid[BTRFS_UUID_SIZE] = {0};
2300
2301 if (!capable(CAP_SYS_ADMIN))
2302 return -EPERM;
2303
2304 di_args = memdup_user(arg, sizeof(*di_args));
2305 if (IS_ERR(di_args))
2306 return PTR_ERR(di_args);
2307
2308 if (memcmp(empty_uuid, di_args->uuid, BTRFS_UUID_SIZE) != 0)
2309 s_uuid = di_args->uuid;
2310
2311 mutex_lock(&fs_devices->device_list_mutex);
2312 dev = btrfs_find_device(root, di_args->devid, s_uuid, NULL);
2313 mutex_unlock(&fs_devices->device_list_mutex);
2314
2315 if (!dev) {
2316 ret = -ENODEV;
2317 goto out;
2318 }
2319
2320 di_args->devid = dev->devid;
2321 di_args->bytes_used = dev->bytes_used;
2322 di_args->total_bytes = dev->total_bytes;
2323 memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2324 if (dev->name) {
2325 struct rcu_string *name;
2326
2327 rcu_read_lock();
2328 name = rcu_dereference(dev->name);
2329 strncpy(di_args->path, name->str, sizeof(di_args->path));
2330 rcu_read_unlock();
2331 di_args->path[sizeof(di_args->path) - 1] = 0;
2332 } else {
2333 di_args->path[0] = '\0';
2334 }
2335
2336 out:
2337 if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2338 ret = -EFAULT;
2339
2340 kfree(di_args);
2341 return ret;
2342 }
2343
2344 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
2345 u64 off, u64 olen, u64 destoff)
2346 {
2347 struct inode *inode = fdentry(file)->d_inode;
2348 struct btrfs_root *root = BTRFS_I(inode)->root;
2349 struct file *src_file;
2350 struct inode *src;
2351 struct btrfs_trans_handle *trans;
2352 struct btrfs_path *path;
2353 struct extent_buffer *leaf;
2354 char *buf;
2355 struct btrfs_key key;
2356 u32 nritems;
2357 int slot;
2358 int ret;
2359 u64 len = olen;
2360 u64 bs = root->fs_info->sb->s_blocksize;
2361 u64 hint_byte;
2362
2363 /*
2364 * TODO:
2365 * - split compressed inline extents. annoying: we need to
2366 * decompress into destination's address_space (the file offset
2367 * may change, so source mapping won't do), then recompress (or
2368 * otherwise reinsert) a subrange.
2369 * - allow ranges within the same file to be cloned (provided
2370 * they don't overlap)?
2371 */
2372
2373 /* the destination must be opened for writing */
2374 if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
2375 return -EINVAL;
2376
2377 if (btrfs_root_readonly(root))
2378 return -EROFS;
2379
2380 ret = mnt_want_write_file(file);
2381 if (ret)
2382 return ret;
2383
2384 src_file = fget(srcfd);
2385 if (!src_file) {
2386 ret = -EBADF;
2387 goto out_drop_write;
2388 }
2389
2390 ret = -EXDEV;
2391 if (src_file->f_path.mnt != file->f_path.mnt)
2392 goto out_fput;
2393
2394 src = src_file->f_dentry->d_inode;
2395
2396 ret = -EINVAL;
2397 if (src == inode)
2398 goto out_fput;
2399
2400 /* the src must be open for reading */
2401 if (!(src_file->f_mode & FMODE_READ))
2402 goto out_fput;
2403
2404 /* don't make the dst file partly checksummed */
2405 if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
2406 (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
2407 goto out_fput;
2408
2409 ret = -EISDIR;
2410 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
2411 goto out_fput;
2412
2413 ret = -EXDEV;
2414 if (src->i_sb != inode->i_sb)
2415 goto out_fput;
2416
2417 ret = -ENOMEM;
2418 buf = vmalloc(btrfs_level_size(root, 0));
2419 if (!buf)
2420 goto out_fput;
2421
2422 path = btrfs_alloc_path();
2423 if (!path) {
2424 vfree(buf);
2425 goto out_fput;
2426 }
2427 path->reada = 2;
2428
2429 if (inode < src) {
2430 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
2431 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
2432 } else {
2433 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
2434 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
2435 }
2436
2437 /* determine range to clone */
2438 ret = -EINVAL;
2439 if (off + len > src->i_size || off + len < off)
2440 goto out_unlock;
2441 if (len == 0)
2442 olen = len = src->i_size - off;
2443 /* if we extend to eof, continue to block boundary */
2444 if (off + len == src->i_size)
2445 len = ALIGN(src->i_size, bs) - off;
2446
2447 /* verify the end result is block aligned */
2448 if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
2449 !IS_ALIGNED(destoff, bs))
2450 goto out_unlock;
2451
2452 if (destoff > inode->i_size) {
2453 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
2454 if (ret)
2455 goto out_unlock;
2456 }
2457
2458 /* truncate page cache pages from target inode range */
2459 truncate_inode_pages_range(&inode->i_data, destoff,
2460 PAGE_CACHE_ALIGN(destoff + len) - 1);
2461
2462 /* do any pending delalloc/csum calc on src, one way or
2463 another, and lock file content */
2464 while (1) {
2465 struct btrfs_ordered_extent *ordered;
2466 lock_extent(&BTRFS_I(src)->io_tree, off, off+len);
2467 ordered = btrfs_lookup_first_ordered_extent(src, off+len);
2468 if (!ordered &&
2469 !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len,
2470 EXTENT_DELALLOC, 0, NULL))
2471 break;
2472 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len);
2473 if (ordered)
2474 btrfs_put_ordered_extent(ordered);
2475 btrfs_wait_ordered_range(src, off, len);
2476 }
2477
2478 /* clone data */
2479 key.objectid = btrfs_ino(src);
2480 key.type = BTRFS_EXTENT_DATA_KEY;
2481 key.offset = 0;
2482
2483 while (1) {
2484 /*
2485 * note the key will change type as we walk through the
2486 * tree.
2487 */
2488 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
2489 0, 0);
2490 if (ret < 0)
2491 goto out;
2492
2493 nritems = btrfs_header_nritems(path->nodes[0]);
2494 if (path->slots[0] >= nritems) {
2495 ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
2496 if (ret < 0)
2497 goto out;
2498 if (ret > 0)
2499 break;
2500 nritems = btrfs_header_nritems(path->nodes[0]);
2501 }
2502 leaf = path->nodes[0];
2503 slot = path->slots[0];
2504
2505 btrfs_item_key_to_cpu(leaf, &key, slot);
2506 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
2507 key.objectid != btrfs_ino(src))
2508 break;
2509
2510 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
2511 struct btrfs_file_extent_item *extent;
2512 int type;
2513 u32 size;
2514 struct btrfs_key new_key;
2515 u64 disko = 0, diskl = 0;
2516 u64 datao = 0, datal = 0;
2517 u8 comp;
2518 u64 endoff;
2519
2520 size = btrfs_item_size_nr(leaf, slot);
2521 read_extent_buffer(leaf, buf,
2522 btrfs_item_ptr_offset(leaf, slot),
2523 size);
2524
2525 extent = btrfs_item_ptr(leaf, slot,
2526 struct btrfs_file_extent_item);
2527 comp = btrfs_file_extent_compression(leaf, extent);
2528 type = btrfs_file_extent_type(leaf, extent);
2529 if (type == BTRFS_FILE_EXTENT_REG ||
2530 type == BTRFS_FILE_EXTENT_PREALLOC) {
2531 disko = btrfs_file_extent_disk_bytenr(leaf,
2532 extent);
2533 diskl = btrfs_file_extent_disk_num_bytes(leaf,
2534 extent);
2535 datao = btrfs_file_extent_offset(leaf, extent);
2536 datal = btrfs_file_extent_num_bytes(leaf,
2537 extent);
2538 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2539 /* take upper bound, may be compressed */
2540 datal = btrfs_file_extent_ram_bytes(leaf,
2541 extent);
2542 }
2543 btrfs_release_path(path);
2544
2545 if (key.offset + datal <= off ||
2546 key.offset >= off+len)
2547 goto next;
2548
2549 memcpy(&new_key, &key, sizeof(new_key));
2550 new_key.objectid = btrfs_ino(inode);
2551 if (off <= key.offset)
2552 new_key.offset = key.offset + destoff - off;
2553 else
2554 new_key.offset = destoff;
2555
2556 /*
2557 * 1 - adjusting old extent (we may have to split it)
2558 * 1 - add new extent
2559 * 1 - inode update
2560 */
2561 trans = btrfs_start_transaction(root, 3);
2562 if (IS_ERR(trans)) {
2563 ret = PTR_ERR(trans);
2564 goto out;
2565 }
2566
2567 if (type == BTRFS_FILE_EXTENT_REG ||
2568 type == BTRFS_FILE_EXTENT_PREALLOC) {
2569 /*
2570 * a | --- range to clone ---| b
2571 * | ------------- extent ------------- |
2572 */
2573
2574 /* substract range b */
2575 if (key.offset + datal > off + len)
2576 datal = off + len - key.offset;
2577
2578 /* substract range a */
2579 if (off > key.offset) {
2580 datao += off - key.offset;
2581 datal -= off - key.offset;
2582 }
2583
2584 ret = btrfs_drop_extents(trans, inode,
2585 new_key.offset,
2586 new_key.offset + datal,
2587 &hint_byte, 1);
2588 if (ret) {
2589 btrfs_abort_transaction(trans, root,
2590 ret);
2591 btrfs_end_transaction(trans, root);
2592 goto out;
2593 }
2594
2595 ret = btrfs_insert_empty_item(trans, root, path,
2596 &new_key, size);
2597 if (ret) {
2598 btrfs_abort_transaction(trans, root,
2599 ret);
2600 btrfs_end_transaction(trans, root);
2601 goto out;
2602 }
2603
2604 leaf = path->nodes[0];
2605 slot = path->slots[0];
2606 write_extent_buffer(leaf, buf,
2607 btrfs_item_ptr_offset(leaf, slot),
2608 size);
2609
2610 extent = btrfs_item_ptr(leaf, slot,
2611 struct btrfs_file_extent_item);
2612
2613 /* disko == 0 means it's a hole */
2614 if (!disko)
2615 datao = 0;
2616
2617 btrfs_set_file_extent_offset(leaf, extent,
2618 datao);
2619 btrfs_set_file_extent_num_bytes(leaf, extent,
2620 datal);
2621 if (disko) {
2622 inode_add_bytes(inode, datal);
2623 ret = btrfs_inc_extent_ref(trans, root,
2624 disko, diskl, 0,
2625 root->root_key.objectid,
2626 btrfs_ino(inode),
2627 new_key.offset - datao,
2628 0);
2629 if (ret) {
2630 btrfs_abort_transaction(trans,
2631 root,
2632 ret);
2633 btrfs_end_transaction(trans,
2634 root);
2635 goto out;
2636
2637 }
2638 }
2639 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2640 u64 skip = 0;
2641 u64 trim = 0;
2642 if (off > key.offset) {
2643 skip = off - key.offset;
2644 new_key.offset += skip;
2645 }
2646
2647 if (key.offset + datal > off+len)
2648 trim = key.offset + datal - (off+len);
2649
2650 if (comp && (skip || trim)) {
2651 ret = -EINVAL;
2652 btrfs_end_transaction(trans, root);
2653 goto out;
2654 }
2655 size -= skip + trim;
2656 datal -= skip + trim;
2657
2658 ret = btrfs_drop_extents(trans, inode,
2659 new_key.offset,
2660 new_key.offset + datal,
2661 &hint_byte, 1);
2662 if (ret) {
2663 btrfs_abort_transaction(trans, root,
2664 ret);
2665 btrfs_end_transaction(trans, root);
2666 goto out;
2667 }
2668
2669 ret = btrfs_insert_empty_item(trans, root, path,
2670 &new_key, size);
2671 if (ret) {
2672 btrfs_abort_transaction(trans, root,
2673 ret);
2674 btrfs_end_transaction(trans, root);
2675 goto out;
2676 }
2677
2678 if (skip) {
2679 u32 start =
2680 btrfs_file_extent_calc_inline_size(0);
2681 memmove(buf+start, buf+start+skip,
2682 datal);
2683 }
2684
2685 leaf = path->nodes[0];
2686 slot = path->slots[0];
2687 write_extent_buffer(leaf, buf,
2688 btrfs_item_ptr_offset(leaf, slot),
2689 size);
2690 inode_add_bytes(inode, datal);
2691 }
2692
2693 btrfs_mark_buffer_dirty(leaf);
2694 btrfs_release_path(path);
2695
2696 inode_inc_iversion(inode);
2697 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2698
2699 /*
2700 * we round up to the block size at eof when
2701 * determining which extents to clone above,
2702 * but shouldn't round up the file size
2703 */
2704 endoff = new_key.offset + datal;
2705 if (endoff > destoff+olen)
2706 endoff = destoff+olen;
2707 if (endoff > inode->i_size)
2708 btrfs_i_size_write(inode, endoff);
2709
2710 ret = btrfs_update_inode(trans, root, inode);
2711 if (ret) {
2712 btrfs_abort_transaction(trans, root, ret);
2713 btrfs_end_transaction(trans, root);
2714 goto out;
2715 }
2716 ret = btrfs_end_transaction(trans, root);
2717 }
2718 next:
2719 btrfs_release_path(path);
2720 key.offset++;
2721 }
2722 ret = 0;
2723 out:
2724 btrfs_release_path(path);
2725 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len);
2726 out_unlock:
2727 mutex_unlock(&src->i_mutex);
2728 mutex_unlock(&inode->i_mutex);
2729 vfree(buf);
2730 btrfs_free_path(path);
2731 out_fput:
2732 fput(src_file);
2733 out_drop_write:
2734 mnt_drop_write_file(file);
2735 return ret;
2736 }
2737
2738 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2739 {
2740 struct btrfs_ioctl_clone_range_args args;
2741
2742 if (copy_from_user(&args, argp, sizeof(args)))
2743 return -EFAULT;
2744 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2745 args.src_length, args.dest_offset);
2746 }
2747
2748 /*
2749 * there are many ways the trans_start and trans_end ioctls can lead
2750 * to deadlocks. They should only be used by applications that
2751 * basically own the machine, and have a very in depth understanding
2752 * of all the possible deadlocks and enospc problems.
2753 */
2754 static long btrfs_ioctl_trans_start(struct file *file)
2755 {
2756 struct inode *inode = fdentry(file)->d_inode;
2757 struct btrfs_root *root = BTRFS_I(inode)->root;
2758 struct btrfs_trans_handle *trans;
2759 int ret;
2760
2761 ret = -EPERM;
2762 if (!capable(CAP_SYS_ADMIN))
2763 goto out;
2764
2765 ret = -EINPROGRESS;
2766 if (file->private_data)
2767 goto out;
2768
2769 ret = -EROFS;
2770 if (btrfs_root_readonly(root))
2771 goto out;
2772
2773 ret = mnt_want_write_file(file);
2774 if (ret)
2775 goto out;
2776
2777 atomic_inc(&root->fs_info->open_ioctl_trans);
2778
2779 ret = -ENOMEM;
2780 trans = btrfs_start_ioctl_transaction(root);
2781 if (IS_ERR(trans))
2782 goto out_drop;
2783
2784 file->private_data = trans;
2785 return 0;
2786
2787 out_drop:
2788 atomic_dec(&root->fs_info->open_ioctl_trans);
2789 mnt_drop_write_file(file);
2790 out:
2791 return ret;
2792 }
2793
2794 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2795 {
2796 struct inode *inode = fdentry(file)->d_inode;
2797 struct btrfs_root *root = BTRFS_I(inode)->root;
2798 struct btrfs_root *new_root;
2799 struct btrfs_dir_item *di;
2800 struct btrfs_trans_handle *trans;
2801 struct btrfs_path *path;
2802 struct btrfs_key location;
2803 struct btrfs_disk_key disk_key;
2804 u64 objectid = 0;
2805 u64 dir_id;
2806
2807 if (!capable(CAP_SYS_ADMIN))
2808 return -EPERM;
2809
2810 if (copy_from_user(&objectid, argp, sizeof(objectid)))
2811 return -EFAULT;
2812
2813 if (!objectid)
2814 objectid = root->root_key.objectid;
2815
2816 location.objectid = objectid;
2817 location.type = BTRFS_ROOT_ITEM_KEY;
2818 location.offset = (u64)-1;
2819
2820 new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2821 if (IS_ERR(new_root))
2822 return PTR_ERR(new_root);
2823
2824 if (btrfs_root_refs(&new_root->root_item) == 0)
2825 return -ENOENT;
2826
2827 path = btrfs_alloc_path();
2828 if (!path)
2829 return -ENOMEM;
2830 path->leave_spinning = 1;
2831
2832 trans = btrfs_start_transaction(root, 1);
2833 if (IS_ERR(trans)) {
2834 btrfs_free_path(path);
2835 return PTR_ERR(trans);
2836 }
2837
2838 dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
2839 di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2840 dir_id, "default", 7, 1);
2841 if (IS_ERR_OR_NULL(di)) {
2842 btrfs_free_path(path);
2843 btrfs_end_transaction(trans, root);
2844 printk(KERN_ERR "Umm, you don't have the default dir item, "
2845 "this isn't going to work\n");
2846 return -ENOENT;
2847 }
2848
2849 btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2850 btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2851 btrfs_mark_buffer_dirty(path->nodes[0]);
2852 btrfs_free_path(path);
2853
2854 btrfs_set_fs_incompat(root->fs_info, DEFAULT_SUBVOL);
2855 btrfs_end_transaction(trans, root);
2856
2857 return 0;
2858 }
2859
2860 static void get_block_group_info(struct list_head *groups_list,
2861 struct btrfs_ioctl_space_info *space)
2862 {
2863 struct btrfs_block_group_cache *block_group;
2864
2865 space->total_bytes = 0;
2866 space->used_bytes = 0;
2867 space->flags = 0;
2868 list_for_each_entry(block_group, groups_list, list) {
2869 space->flags = block_group->flags;
2870 space->total_bytes += block_group->key.offset;
2871 space->used_bytes +=
2872 btrfs_block_group_used(&block_group->item);
2873 }
2874 }
2875
2876 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
2877 {
2878 struct btrfs_ioctl_space_args space_args;
2879 struct btrfs_ioctl_space_info space;
2880 struct btrfs_ioctl_space_info *dest;
2881 struct btrfs_ioctl_space_info *dest_orig;
2882 struct btrfs_ioctl_space_info __user *user_dest;
2883 struct btrfs_space_info *info;
2884 u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2885 BTRFS_BLOCK_GROUP_SYSTEM,
2886 BTRFS_BLOCK_GROUP_METADATA,
2887 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2888 int num_types = 4;
2889 int alloc_size;
2890 int ret = 0;
2891 u64 slot_count = 0;
2892 int i, c;
2893
2894 if (copy_from_user(&space_args,
2895 (struct btrfs_ioctl_space_args __user *)arg,
2896 sizeof(space_args)))
2897 return -EFAULT;
2898
2899 for (i = 0; i < num_types; i++) {
2900 struct btrfs_space_info *tmp;
2901
2902 info = NULL;
2903 rcu_read_lock();
2904 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2905 list) {
2906 if (tmp->flags == types[i]) {
2907 info = tmp;
2908 break;
2909 }
2910 }
2911 rcu_read_unlock();
2912
2913 if (!info)
2914 continue;
2915
2916 down_read(&info->groups_sem);
2917 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2918 if (!list_empty(&info->block_groups[c]))
2919 slot_count++;
2920 }
2921 up_read(&info->groups_sem);
2922 }
2923
2924 /* space_slots == 0 means they are asking for a count */
2925 if (space_args.space_slots == 0) {
2926 space_args.total_spaces = slot_count;
2927 goto out;
2928 }
2929
2930 slot_count = min_t(u64, space_args.space_slots, slot_count);
2931
2932 alloc_size = sizeof(*dest) * slot_count;
2933
2934 /* we generally have at most 6 or so space infos, one for each raid
2935 * level. So, a whole page should be more than enough for everyone
2936 */
2937 if (alloc_size > PAGE_CACHE_SIZE)
2938 return -ENOMEM;
2939
2940 space_args.total_spaces = 0;
2941 dest = kmalloc(alloc_size, GFP_NOFS);
2942 if (!dest)
2943 return -ENOMEM;
2944 dest_orig = dest;
2945
2946 /* now we have a buffer to copy into */
2947 for (i = 0; i < num_types; i++) {
2948 struct btrfs_space_info *tmp;
2949
2950 if (!slot_count)
2951 break;
2952
2953 info = NULL;
2954 rcu_read_lock();
2955 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2956 list) {
2957 if (tmp->flags == types[i]) {
2958 info = tmp;
2959 break;
2960 }
2961 }
2962 rcu_read_unlock();
2963
2964 if (!info)
2965 continue;
2966 down_read(&info->groups_sem);
2967 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2968 if (!list_empty(&info->block_groups[c])) {
2969 get_block_group_info(&info->block_groups[c],
2970 &space);
2971 memcpy(dest, &space, sizeof(space));
2972 dest++;
2973 space_args.total_spaces++;
2974 slot_count--;
2975 }
2976 if (!slot_count)
2977 break;
2978 }
2979 up_read(&info->groups_sem);
2980 }
2981
2982 user_dest = (struct btrfs_ioctl_space_info __user *)
2983 (arg + sizeof(struct btrfs_ioctl_space_args));
2984
2985 if (copy_to_user(user_dest, dest_orig, alloc_size))
2986 ret = -EFAULT;
2987
2988 kfree(dest_orig);
2989 out:
2990 if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
2991 ret = -EFAULT;
2992
2993 return ret;
2994 }
2995
2996 /*
2997 * there are many ways the trans_start and trans_end ioctls can lead
2998 * to deadlocks. They should only be used by applications that
2999 * basically own the machine, and have a very in depth understanding
3000 * of all the possible deadlocks and enospc problems.
3001 */
3002 long btrfs_ioctl_trans_end(struct file *file)
3003 {
3004 struct inode *inode = fdentry(file)->d_inode;
3005 struct btrfs_root *root = BTRFS_I(inode)->root;
3006 struct btrfs_trans_handle *trans;
3007
3008 trans = file->private_data;
3009 if (!trans)
3010 return -EINVAL;
3011 file->private_data = NULL;
3012
3013 btrfs_end_transaction(trans, root);
3014
3015 atomic_dec(&root->fs_info->open_ioctl_trans);
3016
3017 mnt_drop_write_file(file);
3018 return 0;
3019 }
3020
3021 static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp)
3022 {
3023 struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
3024 struct btrfs_trans_handle *trans;
3025 u64 transid;
3026 int ret;
3027
3028 trans = btrfs_start_transaction(root, 0);
3029 if (IS_ERR(trans))
3030 return PTR_ERR(trans);
3031 transid = trans->transid;
3032 ret = btrfs_commit_transaction_async(trans, root, 0);
3033 if (ret) {
3034 btrfs_end_transaction(trans, root);
3035 return ret;
3036 }
3037
3038 if (argp)
3039 if (copy_to_user(argp, &transid, sizeof(transid)))
3040 return -EFAULT;
3041 return 0;
3042 }
3043
3044 static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp)
3045 {
3046 struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
3047 u64 transid;
3048
3049 if (argp) {
3050 if (copy_from_user(&transid, argp, sizeof(transid)))
3051 return -EFAULT;
3052 } else {
3053 transid = 0; /* current trans */
3054 }
3055 return btrfs_wait_for_commit(root, transid);
3056 }
3057
3058 static long btrfs_ioctl_scrub(struct btrfs_root *root, void __user *arg)
3059 {
3060 int ret;
3061 struct btrfs_ioctl_scrub_args *sa;
3062
3063 if (!capable(CAP_SYS_ADMIN))
3064 return -EPERM;
3065
3066 sa = memdup_user(arg, sizeof(*sa));
3067 if (IS_ERR(sa))
3068 return PTR_ERR(sa);
3069
3070 ret = btrfs_scrub_dev(root, sa->devid, sa->start, sa->end,
3071 &sa->progress, sa->flags & BTRFS_SCRUB_READONLY);
3072
3073 if (copy_to_user(arg, sa, sizeof(*sa)))
3074 ret = -EFAULT;
3075
3076 kfree(sa);
3077 return ret;
3078 }
3079
3080 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
3081 {
3082 if (!capable(CAP_SYS_ADMIN))
3083 return -EPERM;
3084
3085 return btrfs_scrub_cancel(root);
3086 }
3087
3088 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
3089 void __user *arg)
3090 {
3091 struct btrfs_ioctl_scrub_args *sa;
3092 int ret;
3093
3094 if (!capable(CAP_SYS_ADMIN))
3095 return -EPERM;
3096
3097 sa = memdup_user(arg, sizeof(*sa));
3098 if (IS_ERR(sa))
3099 return PTR_ERR(sa);
3100
3101 ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
3102
3103 if (copy_to_user(arg, sa, sizeof(*sa)))
3104 ret = -EFAULT;
3105
3106 kfree(sa);
3107 return ret;
3108 }
3109
3110 static long btrfs_ioctl_get_dev_stats(struct btrfs_root *root,
3111 void __user *arg)
3112 {
3113 struct btrfs_ioctl_get_dev_stats *sa;
3114 int ret;
3115
3116 sa = memdup_user(arg, sizeof(*sa));
3117 if (IS_ERR(sa))
3118 return PTR_ERR(sa);
3119
3120 if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
3121 kfree(sa);
3122 return -EPERM;
3123 }
3124
3125 ret = btrfs_get_dev_stats(root, sa);
3126
3127 if (copy_to_user(arg, sa, sizeof(*sa)))
3128 ret = -EFAULT;
3129
3130 kfree(sa);
3131 return ret;
3132 }
3133
3134 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
3135 {
3136 int ret = 0;
3137 int i;
3138 u64 rel_ptr;
3139 int size;
3140 struct btrfs_ioctl_ino_path_args *ipa = NULL;
3141 struct inode_fs_paths *ipath = NULL;
3142 struct btrfs_path *path;
3143
3144 if (!capable(CAP_SYS_ADMIN))
3145 return -EPERM;
3146
3147 path = btrfs_alloc_path();
3148 if (!path) {
3149 ret = -ENOMEM;
3150 goto out;
3151 }
3152
3153 ipa = memdup_user(arg, sizeof(*ipa));
3154 if (IS_ERR(ipa)) {
3155 ret = PTR_ERR(ipa);
3156 ipa = NULL;
3157 goto out;
3158 }
3159
3160 size = min_t(u32, ipa->size, 4096);
3161 ipath = init_ipath(size, root, path);
3162 if (IS_ERR(ipath)) {
3163 ret = PTR_ERR(ipath);
3164 ipath = NULL;
3165 goto out;
3166 }
3167
3168 ret = paths_from_inode(ipa->inum, ipath);
3169 if (ret < 0)
3170 goto out;
3171
3172 for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
3173 rel_ptr = ipath->fspath->val[i] -
3174 (u64)(unsigned long)ipath->fspath->val;
3175 ipath->fspath->val[i] = rel_ptr;
3176 }
3177
3178 ret = copy_to_user((void *)(unsigned long)ipa->fspath,
3179 (void *)(unsigned long)ipath->fspath, size);
3180 if (ret) {
3181 ret = -EFAULT;
3182 goto out;
3183 }
3184
3185 out:
3186 btrfs_free_path(path);
3187 free_ipath(ipath);
3188 kfree(ipa);
3189
3190 return ret;
3191 }
3192
3193 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
3194 {
3195 struct btrfs_data_container *inodes = ctx;
3196 const size_t c = 3 * sizeof(u64);
3197
3198 if (inodes->bytes_left >= c) {
3199 inodes->bytes_left -= c;
3200 inodes->val[inodes->elem_cnt] = inum;
3201 inodes->val[inodes->elem_cnt + 1] = offset;
3202 inodes->val[inodes->elem_cnt + 2] = root;
3203 inodes->elem_cnt += 3;
3204 } else {
3205 inodes->bytes_missing += c - inodes->bytes_left;
3206 inodes->bytes_left = 0;
3207 inodes->elem_missed += 3;
3208 }
3209
3210 return 0;
3211 }
3212
3213 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
3214 void __user *arg)
3215 {
3216 int ret = 0;
3217 int size;
3218 u64 extent_item_pos;
3219 struct btrfs_ioctl_logical_ino_args *loi;
3220 struct btrfs_data_container *inodes = NULL;
3221 struct btrfs_path *path = NULL;
3222 struct btrfs_key key;
3223
3224 if (!capable(CAP_SYS_ADMIN))
3225 return -EPERM;
3226
3227 loi = memdup_user(arg, sizeof(*loi));
3228 if (IS_ERR(loi)) {
3229 ret = PTR_ERR(loi);
3230 loi = NULL;
3231 goto out;
3232 }
3233
3234 path = btrfs_alloc_path();
3235 if (!path) {
3236 ret = -ENOMEM;
3237 goto out;
3238 }
3239
3240 size = min_t(u32, loi->size, 4096);
3241 inodes = init_data_container(size);
3242 if (IS_ERR(inodes)) {
3243 ret = PTR_ERR(inodes);
3244 inodes = NULL;
3245 goto out;
3246 }
3247
3248 ret = extent_from_logical(root->fs_info, loi->logical, path, &key);
3249 btrfs_release_path(path);
3250
3251 if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK)
3252 ret = -ENOENT;
3253 if (ret < 0)
3254 goto out;
3255
3256 extent_item_pos = loi->logical - key.objectid;
3257 ret = iterate_extent_inodes(root->fs_info, key.objectid,
3258 extent_item_pos, 0, build_ino_list,
3259 inodes);
3260
3261 if (ret < 0)
3262 goto out;
3263
3264 ret = copy_to_user((void *)(unsigned long)loi->inodes,
3265 (void *)(unsigned long)inodes, size);
3266 if (ret)
3267 ret = -EFAULT;
3268
3269 out:
3270 btrfs_free_path(path);
3271 kfree(inodes);
3272 kfree(loi);
3273
3274 return ret;
3275 }
3276
3277 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
3278 struct btrfs_ioctl_balance_args *bargs)
3279 {
3280 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3281
3282 bargs->flags = bctl->flags;
3283
3284 if (atomic_read(&fs_info->balance_running))
3285 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
3286 if (atomic_read(&fs_info->balance_pause_req))
3287 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
3288 if (atomic_read(&fs_info->balance_cancel_req))
3289 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
3290
3291 memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
3292 memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
3293 memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
3294
3295 if (lock) {
3296 spin_lock(&fs_info->balance_lock);
3297 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3298 spin_unlock(&fs_info->balance_lock);
3299 } else {
3300 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3301 }
3302 }
3303
3304 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
3305 {
3306 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3307 struct btrfs_fs_info *fs_info = root->fs_info;
3308 struct btrfs_ioctl_balance_args *bargs;
3309 struct btrfs_balance_control *bctl;
3310 int ret;
3311
3312 if (!capable(CAP_SYS_ADMIN))
3313 return -EPERM;
3314
3315 ret = mnt_want_write_file(file);
3316 if (ret)
3317 return ret;
3318
3319 mutex_lock(&fs_info->volume_mutex);
3320 mutex_lock(&fs_info->balance_mutex);
3321
3322 if (arg) {
3323 bargs = memdup_user(arg, sizeof(*bargs));
3324 if (IS_ERR(bargs)) {
3325 ret = PTR_ERR(bargs);
3326 goto out;
3327 }
3328
3329 if (bargs->flags & BTRFS_BALANCE_RESUME) {
3330 if (!fs_info->balance_ctl) {
3331 ret = -ENOTCONN;
3332 goto out_bargs;
3333 }
3334
3335 bctl = fs_info->balance_ctl;
3336 spin_lock(&fs_info->balance_lock);
3337 bctl->flags |= BTRFS_BALANCE_RESUME;
3338 spin_unlock(&fs_info->balance_lock);
3339
3340 goto do_balance;
3341 }
3342 } else {
3343 bargs = NULL;
3344 }
3345
3346 if (fs_info->balance_ctl) {
3347 ret = -EINPROGRESS;
3348 goto out_bargs;
3349 }
3350
3351 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3352 if (!bctl) {
3353 ret = -ENOMEM;
3354 goto out_bargs;
3355 }
3356
3357 bctl->fs_info = fs_info;
3358 if (arg) {
3359 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
3360 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
3361 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
3362
3363 bctl->flags = bargs->flags;
3364 } else {
3365 /* balance everything - no filters */
3366 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
3367 }
3368
3369 do_balance:
3370 ret = btrfs_balance(bctl, bargs);
3371 /*
3372 * bctl is freed in __cancel_balance or in free_fs_info if
3373 * restriper was paused all the way until unmount
3374 */
3375 if (arg) {
3376 if (copy_to_user(arg, bargs, sizeof(*bargs)))
3377 ret = -EFAULT;
3378 }
3379
3380 out_bargs:
3381 kfree(bargs);
3382 out:
3383 mutex_unlock(&fs_info->balance_mutex);
3384 mutex_unlock(&fs_info->volume_mutex);
3385 mnt_drop_write_file(file);
3386 return ret;
3387 }
3388
3389 static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
3390 {
3391 if (!capable(CAP_SYS_ADMIN))
3392 return -EPERM;
3393
3394 switch (cmd) {
3395 case BTRFS_BALANCE_CTL_PAUSE:
3396 return btrfs_pause_balance(root->fs_info);
3397 case BTRFS_BALANCE_CTL_CANCEL:
3398 return btrfs_cancel_balance(root->fs_info);
3399 }
3400
3401 return -EINVAL;
3402 }
3403
3404 static long btrfs_ioctl_balance_progress(struct btrfs_root *root,
3405 void __user *arg)
3406 {
3407 struct btrfs_fs_info *fs_info = root->fs_info;
3408 struct btrfs_ioctl_balance_args *bargs;
3409 int ret = 0;
3410
3411 if (!capable(CAP_SYS_ADMIN))
3412 return -EPERM;
3413
3414 mutex_lock(&fs_info->balance_mutex);
3415 if (!fs_info->balance_ctl) {
3416 ret = -ENOTCONN;
3417 goto out;
3418 }
3419
3420 bargs = kzalloc(sizeof(*bargs), GFP_NOFS);
3421 if (!bargs) {
3422 ret = -ENOMEM;
3423 goto out;
3424 }
3425
3426 update_ioctl_balance_args(fs_info, 1, bargs);
3427
3428 if (copy_to_user(arg, bargs, sizeof(*bargs)))
3429 ret = -EFAULT;
3430
3431 kfree(bargs);
3432 out:
3433 mutex_unlock(&fs_info->balance_mutex);
3434 return ret;
3435 }
3436
3437 static long btrfs_ioctl_quota_ctl(struct btrfs_root *root, void __user *arg)
3438 {
3439 struct btrfs_ioctl_quota_ctl_args *sa;
3440 struct btrfs_trans_handle *trans = NULL;
3441 int ret;
3442 int err;
3443
3444 if (!capable(CAP_SYS_ADMIN))
3445 return -EPERM;
3446
3447 if (root->fs_info->sb->s_flags & MS_RDONLY)
3448 return -EROFS;
3449
3450 sa = memdup_user(arg, sizeof(*sa));
3451 if (IS_ERR(sa))
3452 return PTR_ERR(sa);
3453
3454 if (sa->cmd != BTRFS_QUOTA_CTL_RESCAN) {
3455 trans = btrfs_start_transaction(root, 2);
3456 if (IS_ERR(trans)) {
3457 ret = PTR_ERR(trans);
3458 goto out;
3459 }
3460 }
3461
3462 switch (sa->cmd) {
3463 case BTRFS_QUOTA_CTL_ENABLE:
3464 ret = btrfs_quota_enable(trans, root->fs_info);
3465 break;
3466 case BTRFS_QUOTA_CTL_DISABLE:
3467 ret = btrfs_quota_disable(trans, root->fs_info);
3468 break;
3469 case BTRFS_QUOTA_CTL_RESCAN:
3470 ret = btrfs_quota_rescan(root->fs_info);
3471 break;
3472 default:
3473 ret = -EINVAL;
3474 break;
3475 }
3476
3477 if (copy_to_user(arg, sa, sizeof(*sa)))
3478 ret = -EFAULT;
3479
3480 if (trans) {
3481 err = btrfs_commit_transaction(trans, root);
3482 if (err && !ret)
3483 ret = err;
3484 }
3485
3486 out:
3487 kfree(sa);
3488 return ret;
3489 }
3490
3491 static long btrfs_ioctl_qgroup_assign(struct btrfs_root *root, void __user *arg)
3492 {
3493 struct btrfs_ioctl_qgroup_assign_args *sa;
3494 struct btrfs_trans_handle *trans;
3495 int ret;
3496 int err;
3497
3498 if (!capable(CAP_SYS_ADMIN))
3499 return -EPERM;
3500
3501 if (root->fs_info->sb->s_flags & MS_RDONLY)
3502 return -EROFS;
3503
3504 sa = memdup_user(arg, sizeof(*sa));
3505 if (IS_ERR(sa))
3506 return PTR_ERR(sa);
3507
3508 trans = btrfs_join_transaction(root);
3509 if (IS_ERR(trans)) {
3510 ret = PTR_ERR(trans);
3511 goto out;
3512 }
3513
3514 /* FIXME: check if the IDs really exist */
3515 if (sa->assign) {
3516 ret = btrfs_add_qgroup_relation(trans, root->fs_info,
3517 sa->src, sa->dst);
3518 } else {
3519 ret = btrfs_del_qgroup_relation(trans, root->fs_info,
3520 sa->src, sa->dst);
3521 }
3522
3523 err = btrfs_end_transaction(trans, root);
3524 if (err && !ret)
3525 ret = err;
3526
3527 out:
3528 kfree(sa);
3529 return ret;
3530 }
3531
3532 static long btrfs_ioctl_qgroup_create(struct btrfs_root *root, void __user *arg)
3533 {
3534 struct btrfs_ioctl_qgroup_create_args *sa;
3535 struct btrfs_trans_handle *trans;
3536 int ret;
3537 int err;
3538
3539 if (!capable(CAP_SYS_ADMIN))
3540 return -EPERM;
3541
3542 if (root->fs_info->sb->s_flags & MS_RDONLY)
3543 return -EROFS;
3544
3545 sa = memdup_user(arg, sizeof(*sa));
3546 if (IS_ERR(sa))
3547 return PTR_ERR(sa);
3548
3549 trans = btrfs_join_transaction(root);
3550 if (IS_ERR(trans)) {
3551 ret = PTR_ERR(trans);
3552 goto out;
3553 }
3554
3555 /* FIXME: check if the IDs really exist */
3556 if (sa->create) {
3557 ret = btrfs_create_qgroup(trans, root->fs_info, sa->qgroupid,
3558 NULL);
3559 } else {
3560 ret = btrfs_remove_qgroup(trans, root->fs_info, sa->qgroupid);
3561 }
3562
3563 err = btrfs_end_transaction(trans, root);
3564 if (err && !ret)
3565 ret = err;
3566
3567 out:
3568 kfree(sa);
3569 return ret;
3570 }
3571
3572 static long btrfs_ioctl_qgroup_limit(struct btrfs_root *root, void __user *arg)
3573 {
3574 struct btrfs_ioctl_qgroup_limit_args *sa;
3575 struct btrfs_trans_handle *trans;
3576 int ret;
3577 int err;
3578 u64 qgroupid;
3579
3580 if (!capable(CAP_SYS_ADMIN))
3581 return -EPERM;
3582
3583 if (root->fs_info->sb->s_flags & MS_RDONLY)
3584 return -EROFS;
3585
3586 sa = memdup_user(arg, sizeof(*sa));
3587 if (IS_ERR(sa))
3588 return PTR_ERR(sa);
3589
3590 trans = btrfs_join_transaction(root);
3591 if (IS_ERR(trans)) {
3592 ret = PTR_ERR(trans);
3593 goto out;
3594 }
3595
3596 qgroupid = sa->qgroupid;
3597 if (!qgroupid) {
3598 /* take the current subvol as qgroup */
3599 qgroupid = root->root_key.objectid;
3600 }
3601
3602 /* FIXME: check if the IDs really exist */
3603 ret = btrfs_limit_qgroup(trans, root->fs_info, qgroupid, &sa->lim);
3604
3605 err = btrfs_end_transaction(trans, root);
3606 if (err && !ret)
3607 ret = err;
3608
3609 out:
3610 kfree(sa);
3611 return ret;
3612 }
3613
3614 static long btrfs_ioctl_set_received_subvol(struct file *file,
3615 void __user *arg)
3616 {
3617 struct btrfs_ioctl_received_subvol_args *sa = NULL;
3618 struct inode *inode = fdentry(file)->d_inode;
3619 struct btrfs_root *root = BTRFS_I(inode)->root;
3620 struct btrfs_root_item *root_item = &root->root_item;
3621 struct btrfs_trans_handle *trans;
3622 struct timespec ct = CURRENT_TIME;
3623 int ret = 0;
3624
3625 ret = mnt_want_write_file(file);
3626 if (ret < 0)
3627 return ret;
3628
3629 down_write(&root->fs_info->subvol_sem);
3630
3631 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
3632 ret = -EINVAL;
3633 goto out;
3634 }
3635
3636 if (btrfs_root_readonly(root)) {
3637 ret = -EROFS;
3638 goto out;
3639 }
3640
3641 if (!inode_owner_or_capable(inode)) {
3642 ret = -EACCES;
3643 goto out;
3644 }
3645
3646 sa = memdup_user(arg, sizeof(*sa));
3647 if (IS_ERR(sa)) {
3648 ret = PTR_ERR(sa);
3649 sa = NULL;
3650 goto out;
3651 }
3652
3653 trans = btrfs_start_transaction(root, 1);
3654 if (IS_ERR(trans)) {
3655 ret = PTR_ERR(trans);
3656 trans = NULL;
3657 goto out;
3658 }
3659
3660 sa->rtransid = trans->transid;
3661 sa->rtime.sec = ct.tv_sec;
3662 sa->rtime.nsec = ct.tv_nsec;
3663
3664 memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
3665 btrfs_set_root_stransid(root_item, sa->stransid);
3666 btrfs_set_root_rtransid(root_item, sa->rtransid);
3667 root_item->stime.sec = cpu_to_le64(sa->stime.sec);
3668 root_item->stime.nsec = cpu_to_le32(sa->stime.nsec);
3669 root_item->rtime.sec = cpu_to_le64(sa->rtime.sec);
3670 root_item->rtime.nsec = cpu_to_le32(sa->rtime.nsec);
3671
3672 ret = btrfs_update_root(trans, root->fs_info->tree_root,
3673 &root->root_key, &root->root_item);
3674 if (ret < 0) {
3675 btrfs_end_transaction(trans, root);
3676 trans = NULL;
3677 goto out;
3678 } else {
3679 ret = btrfs_commit_transaction(trans, root);
3680 if (ret < 0)
3681 goto out;
3682 }
3683
3684 ret = copy_to_user(arg, sa, sizeof(*sa));
3685 if (ret)
3686 ret = -EFAULT;
3687
3688 out:
3689 kfree(sa);
3690 up_write(&root->fs_info->subvol_sem);
3691 mnt_drop_write_file(file);
3692 return ret;
3693 }
3694
3695 long btrfs_ioctl(struct file *file, unsigned int
3696 cmd, unsigned long arg)
3697 {
3698 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3699 void __user *argp = (void __user *)arg;
3700
3701 switch (cmd) {
3702 case FS_IOC_GETFLAGS:
3703 return btrfs_ioctl_getflags(file, argp);
3704 case FS_IOC_SETFLAGS:
3705 return btrfs_ioctl_setflags(file, argp);
3706 case FS_IOC_GETVERSION:
3707 return btrfs_ioctl_getversion(file, argp);
3708 case FITRIM:
3709 return btrfs_ioctl_fitrim(file, argp);
3710 case BTRFS_IOC_SNAP_CREATE:
3711 return btrfs_ioctl_snap_create(file, argp, 0);
3712 case BTRFS_IOC_SNAP_CREATE_V2:
3713 return btrfs_ioctl_snap_create_v2(file, argp, 0);
3714 case BTRFS_IOC_SUBVOL_CREATE:
3715 return btrfs_ioctl_snap_create(file, argp, 1);
3716 case BTRFS_IOC_SUBVOL_CREATE_V2:
3717 return btrfs_ioctl_snap_create_v2(file, argp, 1);
3718 case BTRFS_IOC_SNAP_DESTROY:
3719 return btrfs_ioctl_snap_destroy(file, argp);
3720 case BTRFS_IOC_SUBVOL_GETFLAGS:
3721 return btrfs_ioctl_subvol_getflags(file, argp);
3722 case BTRFS_IOC_SUBVOL_SETFLAGS:
3723 return btrfs_ioctl_subvol_setflags(file, argp);
3724 case BTRFS_IOC_DEFAULT_SUBVOL:
3725 return btrfs_ioctl_default_subvol(file, argp);
3726 case BTRFS_IOC_DEFRAG:
3727 return btrfs_ioctl_defrag(file, NULL);
3728 case BTRFS_IOC_DEFRAG_RANGE:
3729 return btrfs_ioctl_defrag(file, argp);
3730 case BTRFS_IOC_RESIZE:
3731 return btrfs_ioctl_resize(root, argp);
3732 case BTRFS_IOC_ADD_DEV:
3733 return btrfs_ioctl_add_dev(root, argp);
3734 case BTRFS_IOC_RM_DEV:
3735 return btrfs_ioctl_rm_dev(root, argp);
3736 case BTRFS_IOC_FS_INFO:
3737 return btrfs_ioctl_fs_info(root, argp);
3738 case BTRFS_IOC_DEV_INFO:
3739 return btrfs_ioctl_dev_info(root, argp);
3740 case BTRFS_IOC_BALANCE:
3741 return btrfs_ioctl_balance(file, NULL);
3742 case BTRFS_IOC_CLONE:
3743 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
3744 case BTRFS_IOC_CLONE_RANGE:
3745 return btrfs_ioctl_clone_range(file, argp);
3746 case BTRFS_IOC_TRANS_START:
3747 return btrfs_ioctl_trans_start(file);
3748 case BTRFS_IOC_TRANS_END:
3749 return btrfs_ioctl_trans_end(file);
3750 case BTRFS_IOC_TREE_SEARCH:
3751 return btrfs_ioctl_tree_search(file, argp);
3752 case BTRFS_IOC_INO_LOOKUP:
3753 return btrfs_ioctl_ino_lookup(file, argp);
3754 case BTRFS_IOC_INO_PATHS:
3755 return btrfs_ioctl_ino_to_path(root, argp);
3756 case BTRFS_IOC_LOGICAL_INO:
3757 return btrfs_ioctl_logical_to_ino(root, argp);
3758 case BTRFS_IOC_SPACE_INFO:
3759 return btrfs_ioctl_space_info(root, argp);
3760 case BTRFS_IOC_SYNC:
3761 btrfs_sync_fs(file->f_dentry->d_sb, 1);
3762 return 0;
3763 case BTRFS_IOC_START_SYNC:
3764 return btrfs_ioctl_start_sync(file, argp);
3765 case BTRFS_IOC_WAIT_SYNC:
3766 return btrfs_ioctl_wait_sync(file, argp);
3767 case BTRFS_IOC_SCRUB:
3768 return btrfs_ioctl_scrub(root, argp);
3769 case BTRFS_IOC_SCRUB_CANCEL:
3770 return btrfs_ioctl_scrub_cancel(root, argp);
3771 case BTRFS_IOC_SCRUB_PROGRESS:
3772 return btrfs_ioctl_scrub_progress(root, argp);
3773 case BTRFS_IOC_BALANCE_V2:
3774 return btrfs_ioctl_balance(file, argp);
3775 case BTRFS_IOC_BALANCE_CTL:
3776 return btrfs_ioctl_balance_ctl(root, arg);
3777 case BTRFS_IOC_BALANCE_PROGRESS:
3778 return btrfs_ioctl_balance_progress(root, argp);
3779 case BTRFS_IOC_SET_RECEIVED_SUBVOL:
3780 return btrfs_ioctl_set_received_subvol(file, argp);
3781 case BTRFS_IOC_SEND:
3782 return btrfs_ioctl_send(file, argp);
3783 case BTRFS_IOC_GET_DEV_STATS:
3784 return btrfs_ioctl_get_dev_stats(root, argp);
3785 case BTRFS_IOC_QUOTA_CTL:
3786 return btrfs_ioctl_quota_ctl(root, argp);
3787 case BTRFS_IOC_QGROUP_ASSIGN:
3788 return btrfs_ioctl_qgroup_assign(root, argp);
3789 case BTRFS_IOC_QGROUP_CREATE:
3790 return btrfs_ioctl_qgroup_create(root, argp);
3791 case BTRFS_IOC_QGROUP_LIMIT:
3792 return btrfs_ioctl_qgroup_limit(root, argp);
3793 }
3794
3795 return -ENOTTY;
3796 }
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