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Linux 3.2.58
[linux/fpc-iii.git] / fs / btrfs / ioctl.c
blob7cbe2f8e9b9735c81576d779653110427487e5f5
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/fsnotify.h>
25 #include <linux/pagemap.h>
26 #include <linux/highmem.h>
27 #include <linux/time.h>
28 #include <linux/init.h>
29 #include <linux/string.h>
30 #include <linux/backing-dev.h>
31 #include <linux/mount.h>
32 #include <linux/mpage.h>
33 #include <linux/namei.h>
34 #include <linux/swap.h>
35 #include <linux/writeback.h>
36 #include <linux/statfs.h>
37 #include <linux/compat.h>
38 #include <linux/bit_spinlock.h>
39 #include <linux/security.h>
40 #include <linux/xattr.h>
41 #include <linux/vmalloc.h>
42 #include <linux/slab.h>
43 #include <linux/blkdev.h>
44 #include "compat.h"
45 #include "ctree.h"
46 #include "disk-io.h"
47 #include "transaction.h"
48 #include "btrfs_inode.h"
49 #include "ioctl.h"
50 #include "print-tree.h"
51 #include "volumes.h"
52 #include "locking.h"
53 #include "inode-map.h"
54 #include "backref.h"
55
56 /* Mask out flags that are inappropriate for the given type of inode. */
57 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
58 {
59 if (S_ISDIR(mode))
60 return flags;
61 else if (S_ISREG(mode))
62 return flags & ~FS_DIRSYNC_FL;
63 else
64 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
65 }
66
67 /*
68 * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
69 */
70 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
71 {
72 unsigned int iflags = 0;
73
74 if (flags & BTRFS_INODE_SYNC)
75 iflags |= FS_SYNC_FL;
76 if (flags & BTRFS_INODE_IMMUTABLE)
77 iflags |= FS_IMMUTABLE_FL;
78 if (flags & BTRFS_INODE_APPEND)
79 iflags |= FS_APPEND_FL;
80 if (flags & BTRFS_INODE_NODUMP)
81 iflags |= FS_NODUMP_FL;
82 if (flags & BTRFS_INODE_NOATIME)
83 iflags |= FS_NOATIME_FL;
84 if (flags & BTRFS_INODE_DIRSYNC)
85 iflags |= FS_DIRSYNC_FL;
86 if (flags & BTRFS_INODE_NODATACOW)
87 iflags |= FS_NOCOW_FL;
88
89 if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS))
90 iflags |= FS_COMPR_FL;
91 else if (flags & BTRFS_INODE_NOCOMPRESS)
92 iflags |= FS_NOCOMP_FL;
93
94 return iflags;
95 }
96
97 /*
98 * Update inode->i_flags based on the btrfs internal flags.
99 */
100 void btrfs_update_iflags(struct inode *inode)
101 {
102 struct btrfs_inode *ip = BTRFS_I(inode);
103
104 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
105
106 if (ip->flags & BTRFS_INODE_SYNC)
107 inode->i_flags |= S_SYNC;
108 if (ip->flags & BTRFS_INODE_IMMUTABLE)
109 inode->i_flags |= S_IMMUTABLE;
110 if (ip->flags & BTRFS_INODE_APPEND)
111 inode->i_flags |= S_APPEND;
112 if (ip->flags & BTRFS_INODE_NOATIME)
113 inode->i_flags |= S_NOATIME;
114 if (ip->flags & BTRFS_INODE_DIRSYNC)
115 inode->i_flags |= S_DIRSYNC;
116 }
117
118 /*
119 * Inherit flags from the parent inode.
120 *
121 * Currently only the compression flags and the cow flags are inherited.
122 */
123 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
124 {
125 unsigned int flags;
126
127 if (!dir)
128 return;
129
130 flags = BTRFS_I(dir)->flags;
131
132 if (flags & BTRFS_INODE_NOCOMPRESS) {
133 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
134 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
135 } else if (flags & BTRFS_INODE_COMPRESS) {
136 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
137 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
138 }
139
140 if (flags & BTRFS_INODE_NODATACOW)
141 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
142
143 btrfs_update_iflags(inode);
144 }
145
146 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
147 {
148 struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode);
149 unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
150
151 if (copy_to_user(arg, &flags, sizeof(flags)))
152 return -EFAULT;
153 return 0;
154 }
155
156 static int check_flags(unsigned int flags)
157 {
158 if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
159 FS_NOATIME_FL | FS_NODUMP_FL | \
160 FS_SYNC_FL | FS_DIRSYNC_FL | \
161 FS_NOCOMP_FL | FS_COMPR_FL |
162 FS_NOCOW_FL))
163 return -EOPNOTSUPP;
164
165 if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
166 return -EINVAL;
167
168 return 0;
169 }
170
171 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
172 {
173 struct inode *inode = file->f_path.dentry->d_inode;
174 struct btrfs_inode *ip = BTRFS_I(inode);
175 struct btrfs_root *root = ip->root;
176 struct btrfs_trans_handle *trans;
177 unsigned int flags, oldflags;
178 int ret;
179
180 if (btrfs_root_readonly(root))
181 return -EROFS;
182
183 if (copy_from_user(&flags, arg, sizeof(flags)))
184 return -EFAULT;
185
186 ret = check_flags(flags);
187 if (ret)
188 return ret;
189
190 if (!inode_owner_or_capable(inode))
191 return -EACCES;
192
193 mutex_lock(&inode->i_mutex);
194
195 flags = btrfs_mask_flags(inode->i_mode, flags);
196 oldflags = btrfs_flags_to_ioctl(ip->flags);
197 if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
198 if (!capable(CAP_LINUX_IMMUTABLE)) {
199 ret = -EPERM;
200 goto out_unlock;
201 }
202 }
203
204 ret = mnt_want_write(file->f_path.mnt);
205 if (ret)
206 goto out_unlock;
207
208 if (flags & FS_SYNC_FL)
209 ip->flags |= BTRFS_INODE_SYNC;
210 else
211 ip->flags &= ~BTRFS_INODE_SYNC;
212 if (flags & FS_IMMUTABLE_FL)
213 ip->flags |= BTRFS_INODE_IMMUTABLE;
214 else
215 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
216 if (flags & FS_APPEND_FL)
217 ip->flags |= BTRFS_INODE_APPEND;
218 else
219 ip->flags &= ~BTRFS_INODE_APPEND;
220 if (flags & FS_NODUMP_FL)
221 ip->flags |= BTRFS_INODE_NODUMP;
222 else
223 ip->flags &= ~BTRFS_INODE_NODUMP;
224 if (flags & FS_NOATIME_FL)
225 ip->flags |= BTRFS_INODE_NOATIME;
226 else
227 ip->flags &= ~BTRFS_INODE_NOATIME;
228 if (flags & FS_DIRSYNC_FL)
229 ip->flags |= BTRFS_INODE_DIRSYNC;
230 else
231 ip->flags &= ~BTRFS_INODE_DIRSYNC;
232 if (flags & FS_NOCOW_FL)
233 ip->flags |= BTRFS_INODE_NODATACOW;
234 else
235 ip->flags &= ~BTRFS_INODE_NODATACOW;
236
237 /*
238 * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
239 * flag may be changed automatically if compression code won't make
240 * things smaller.
241 */
242 if (flags & FS_NOCOMP_FL) {
243 ip->flags &= ~BTRFS_INODE_COMPRESS;
244 ip->flags |= BTRFS_INODE_NOCOMPRESS;
245 } else if (flags & FS_COMPR_FL) {
246 ip->flags |= BTRFS_INODE_COMPRESS;
247 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
248 } else {
249 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
250 }
251
252 trans = btrfs_join_transaction(root);
253 BUG_ON(IS_ERR(trans));
254
255 btrfs_update_iflags(inode);
256 inode->i_ctime = CURRENT_TIME;
257 ret = btrfs_update_inode(trans, root, inode);
258 BUG_ON(ret);
259
260 btrfs_end_transaction(trans, root);
261
262 mnt_drop_write(file->f_path.mnt);
263
264 ret = 0;
265 out_unlock:
266 mutex_unlock(&inode->i_mutex);
267 return ret;
268 }
269
270 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
271 {
272 struct inode *inode = file->f_path.dentry->d_inode;
273
274 return put_user(inode->i_generation, arg);
275 }
276
277 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
278 {
279 struct btrfs_root *root = fdentry(file)->d_sb->s_fs_info;
280 struct btrfs_fs_info *fs_info = root->fs_info;
281 struct btrfs_device *device;
282 struct request_queue *q;
283 struct fstrim_range range;
284 u64 minlen = ULLONG_MAX;
285 u64 num_devices = 0;
286 u64 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
287 int ret;
288
289 if (!capable(CAP_SYS_ADMIN))
290 return -EPERM;
291
292 rcu_read_lock();
293 list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
294 dev_list) {
295 if (!device->bdev)
296 continue;
297 q = bdev_get_queue(device->bdev);
298 if (blk_queue_discard(q)) {
299 num_devices++;
300 minlen = min((u64)q->limits.discard_granularity,
301 minlen);
302 }
303 }
304 rcu_read_unlock();
305
306 if (!num_devices)
307 return -EOPNOTSUPP;
308 if (copy_from_user(&range, arg, sizeof(range)))
309 return -EFAULT;
310 if (range.start > total_bytes)
311 return -EINVAL;
312
313 range.len = min(range.len, total_bytes - range.start);
314 range.minlen = max(range.minlen, minlen);
315 ret = btrfs_trim_fs(root, &range);
316 if (ret < 0)
317 return ret;
318
319 if (copy_to_user(arg, &range, sizeof(range)))
320 return -EFAULT;
321
322 return 0;
323 }
324
325 static noinline int create_subvol(struct btrfs_root *root,
326 struct dentry *dentry,
327 char *name, int namelen,
328 u64 *async_transid)
329 {
330 struct btrfs_trans_handle *trans;
331 struct btrfs_key key;
332 struct btrfs_root_item root_item;
333 struct btrfs_inode_item *inode_item;
334 struct extent_buffer *leaf;
335 struct btrfs_root *new_root;
336 struct dentry *parent = dentry->d_parent;
337 struct inode *dir;
338 int ret;
339 int err;
340 u64 objectid;
341 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
342 u64 index = 0;
343
344 ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
345 if (ret)
346 return ret;
347
348 dir = parent->d_inode;
349
350 /*
351 * 1 - inode item
352 * 2 - refs
353 * 1 - root item
354 * 2 - dir items
355 */
356 trans = btrfs_start_transaction(root, 6);
357 if (IS_ERR(trans))
358 return PTR_ERR(trans);
359
360 leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
361 0, objectid, NULL, 0, 0, 0);
362 if (IS_ERR(leaf)) {
363 ret = PTR_ERR(leaf);
364 goto fail;
365 }
366
367 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
368 btrfs_set_header_bytenr(leaf, leaf->start);
369 btrfs_set_header_generation(leaf, trans->transid);
370 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
371 btrfs_set_header_owner(leaf, objectid);
372
373 write_extent_buffer(leaf, root->fs_info->fsid,
374 (unsigned long)btrfs_header_fsid(leaf),
375 BTRFS_FSID_SIZE);
376 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
377 (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
378 BTRFS_UUID_SIZE);
379 btrfs_mark_buffer_dirty(leaf);
380
381 inode_item = &root_item.inode;
382 memset(inode_item, 0, sizeof(*inode_item));
383 inode_item->generation = cpu_to_le64(1);
384 inode_item->size = cpu_to_le64(3);
385 inode_item->nlink = cpu_to_le32(1);
386 inode_item->nbytes = cpu_to_le64(root->leafsize);
387 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
388
389 root_item.flags = 0;
390 root_item.byte_limit = 0;
391 inode_item->flags = cpu_to_le64(BTRFS_INODE_ROOT_ITEM_INIT);
392
393 btrfs_set_root_bytenr(&root_item, leaf->start);
394 btrfs_set_root_generation(&root_item, trans->transid);
395 btrfs_set_root_level(&root_item, 0);
396 btrfs_set_root_refs(&root_item, 1);
397 btrfs_set_root_used(&root_item, leaf->len);
398 btrfs_set_root_last_snapshot(&root_item, 0);
399
400 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
401 root_item.drop_level = 0;
402
403 btrfs_tree_unlock(leaf);
404 free_extent_buffer(leaf);
405 leaf = NULL;
406
407 btrfs_set_root_dirid(&root_item, new_dirid);
408
409 key.objectid = objectid;
410 key.offset = 0;
411 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
412 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
413 &root_item);
414 if (ret)
415 goto fail;
416
417 key.offset = (u64)-1;
418 new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
419 BUG_ON(IS_ERR(new_root));
420
421 btrfs_record_root_in_trans(trans, new_root);
422
423 ret = btrfs_create_subvol_root(trans, new_root, new_dirid);
424 /*
425 * insert the directory item
426 */
427 ret = btrfs_set_inode_index(dir, &index);
428 BUG_ON(ret);
429
430 ret = btrfs_insert_dir_item(trans, root,
431 name, namelen, dir, &key,
432 BTRFS_FT_DIR, index);
433 if (ret)
434 goto fail;
435
436 btrfs_i_size_write(dir, dir->i_size + namelen * 2);
437 ret = btrfs_update_inode(trans, root, dir);
438 BUG_ON(ret);
439
440 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
441 objectid, root->root_key.objectid,
442 btrfs_ino(dir), index, name, namelen);
443
444 BUG_ON(ret);
445
446 d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
447 fail:
448 if (async_transid) {
449 *async_transid = trans->transid;
450 err = btrfs_commit_transaction_async(trans, root, 1);
451 } else {
452 err = btrfs_commit_transaction(trans, root);
453 }
454 if (err && !ret)
455 ret = err;
456 return ret;
457 }
458
459 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
460 char *name, int namelen, u64 *async_transid,
461 bool readonly)
462 {
463 struct inode *inode;
464 struct btrfs_pending_snapshot *pending_snapshot;
465 struct btrfs_trans_handle *trans;
466 int ret;
467
468 if (!root->ref_cows)
469 return -EINVAL;
470
471 pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
472 if (!pending_snapshot)
473 return -ENOMEM;
474
475 btrfs_init_block_rsv(&pending_snapshot->block_rsv);
476 pending_snapshot->dentry = dentry;
477 pending_snapshot->root = root;
478 pending_snapshot->readonly = readonly;
479
480 trans = btrfs_start_transaction(root->fs_info->extent_root, 5);
481 if (IS_ERR(trans)) {
482 ret = PTR_ERR(trans);
483 goto fail;
484 }
485
486 ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
487 BUG_ON(ret);
488
489 spin_lock(&root->fs_info->trans_lock);
490 list_add(&pending_snapshot->list,
491 &trans->transaction->pending_snapshots);
492 spin_unlock(&root->fs_info->trans_lock);
493 if (async_transid) {
494 *async_transid = trans->transid;
495 ret = btrfs_commit_transaction_async(trans,
496 root->fs_info->extent_root, 1);
497 } else {
498 ret = btrfs_commit_transaction(trans,
499 root->fs_info->extent_root);
500 }
501 BUG_ON(ret);
502
503 ret = pending_snapshot->error;
504 if (ret)
505 goto fail;
506
507 ret = btrfs_orphan_cleanup(pending_snapshot->snap);
508 if (ret)
509 goto fail;
510
511 inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
512 if (IS_ERR(inode)) {
513 ret = PTR_ERR(inode);
514 goto fail;
515 }
516 BUG_ON(!inode);
517 d_instantiate(dentry, inode);
518 ret = 0;
519 fail:
520 kfree(pending_snapshot);
521 return ret;
522 }
523
524 /* copy of check_sticky in fs/namei.c()
525 * It's inline, so penalty for filesystems that don't use sticky bit is
526 * minimal.
527 */
528 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode)
529 {
530 uid_t fsuid = current_fsuid();
531
532 if (!(dir->i_mode & S_ISVTX))
533 return 0;
534 if (inode->i_uid == fsuid)
535 return 0;
536 if (dir->i_uid == fsuid)
537 return 0;
538 return !capable(CAP_FOWNER);
539 }
540
541 /* copy of may_delete in fs/namei.c()
542 * Check whether we can remove a link victim from directory dir, check
543 * whether the type of victim is right.
544 * 1. We can't do it if dir is read-only (done in permission())
545 * 2. We should have write and exec permissions on dir
546 * 3. We can't remove anything from append-only dir
547 * 4. We can't do anything with immutable dir (done in permission())
548 * 5. If the sticky bit on dir is set we should either
549 * a. be owner of dir, or
550 * b. be owner of victim, or
551 * c. have CAP_FOWNER capability
552 * 6. If the victim is append-only or immutable we can't do antyhing with
553 * links pointing to it.
554 * 7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
555 * 8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
556 * 9. We can't remove a root or mountpoint.
557 * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
558 * nfs_async_unlink().
559 */
560
561 static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir)
562 {
563 int error;
564
565 if (!victim->d_inode)
566 return -ENOENT;
567
568 BUG_ON(victim->d_parent->d_inode != dir);
569 audit_inode_child(victim, dir);
570
571 error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
572 if (error)
573 return error;
574 if (IS_APPEND(dir))
575 return -EPERM;
576 if (btrfs_check_sticky(dir, victim->d_inode)||
577 IS_APPEND(victim->d_inode)||
578 IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
579 return -EPERM;
580 if (isdir) {
581 if (!S_ISDIR(victim->d_inode->i_mode))
582 return -ENOTDIR;
583 if (IS_ROOT(victim))
584 return -EBUSY;
585 } else if (S_ISDIR(victim->d_inode->i_mode))
586 return -EISDIR;
587 if (IS_DEADDIR(dir))
588 return -ENOENT;
589 if (victim->d_flags & DCACHE_NFSFS_RENAMED)
590 return -EBUSY;
591 return 0;
592 }
593
594 /* copy of may_create in fs/namei.c() */
595 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
596 {
597 if (child->d_inode)
598 return -EEXIST;
599 if (IS_DEADDIR(dir))
600 return -ENOENT;
601 return inode_permission(dir, MAY_WRITE | MAY_EXEC);
602 }
603
604 /*
605 * Create a new subvolume below @parent. This is largely modeled after
606 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
607 * inside this filesystem so it's quite a bit simpler.
608 */
609 static noinline int btrfs_mksubvol(struct path *parent,
610 char *name, int namelen,
611 struct btrfs_root *snap_src,
612 u64 *async_transid, bool readonly)
613 {
614 struct inode *dir = parent->dentry->d_inode;
615 struct dentry *dentry;
616 int error;
617
618 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
619
620 dentry = lookup_one_len(name, parent->dentry, namelen);
621 error = PTR_ERR(dentry);
622 if (IS_ERR(dentry))
623 goto out_unlock;
624
625 error = -EEXIST;
626 if (dentry->d_inode)
627 goto out_dput;
628
629 error = mnt_want_write(parent->mnt);
630 if (error)
631 goto out_dput;
632
633 error = btrfs_may_create(dir, dentry);
634 if (error)
635 goto out_drop_write;
636
637 down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
638
639 if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
640 goto out_up_read;
641
642 if (snap_src) {
643 error = create_snapshot(snap_src, dentry,
644 name, namelen, async_transid, readonly);
645 } else {
646 error = create_subvol(BTRFS_I(dir)->root, dentry,
647 name, namelen, async_transid);
648 }
649 if (!error)
650 fsnotify_mkdir(dir, dentry);
651 out_up_read:
652 up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
653 out_drop_write:
654 mnt_drop_write(parent->mnt);
655 out_dput:
656 dput(dentry);
657 out_unlock:
658 mutex_unlock(&dir->i_mutex);
659 return error;
660 }
661
662 /*
663 * When we're defragging a range, we don't want to kick it off again
664 * if it is really just waiting for delalloc to send it down.
665 * If we find a nice big extent or delalloc range for the bytes in the
666 * file you want to defrag, we return 0 to let you know to skip this
667 * part of the file
668 */
669 static int check_defrag_in_cache(struct inode *inode, u64 offset, int thresh)
670 {
671 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
672 struct extent_map *em = NULL;
673 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
674 u64 end;
675
676 read_lock(&em_tree->lock);
677 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
678 read_unlock(&em_tree->lock);
679
680 if (em) {
681 end = extent_map_end(em);
682 free_extent_map(em);
683 if (end - offset > thresh)
684 return 0;
685 }
686 /* if we already have a nice delalloc here, just stop */
687 thresh /= 2;
688 end = count_range_bits(io_tree, &offset, offset + thresh,
689 thresh, EXTENT_DELALLOC, 1);
690 if (end >= thresh)
691 return 0;
692 return 1;
693 }
694
695 /*
696 * helper function to walk through a file and find extents
697 * newer than a specific transid, and smaller than thresh.
698 *
699 * This is used by the defragging code to find new and small
700 * extents
701 */
702 static int find_new_extents(struct btrfs_root *root,
703 struct inode *inode, u64 newer_than,
704 u64 *off, int thresh)
705 {
706 struct btrfs_path *path;
707 struct btrfs_key min_key;
708 struct btrfs_key max_key;
709 struct extent_buffer *leaf;
710 struct btrfs_file_extent_item *extent;
711 int type;
712 int ret;
713 u64 ino = btrfs_ino(inode);
714
715 path = btrfs_alloc_path();
716 if (!path)
717 return -ENOMEM;
718
719 min_key.objectid = ino;
720 min_key.type = BTRFS_EXTENT_DATA_KEY;
721 min_key.offset = *off;
722
723 max_key.objectid = ino;
724 max_key.type = (u8)-1;
725 max_key.offset = (u64)-1;
726
727 path->keep_locks = 1;
728
729 while(1) {
730 ret = btrfs_search_forward(root, &min_key, &max_key,
731 path, 0, newer_than);
732 if (ret != 0)
733 goto none;
734 if (min_key.objectid != ino)
735 goto none;
736 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
737 goto none;
738
739 leaf = path->nodes[0];
740 extent = btrfs_item_ptr(leaf, path->slots[0],
741 struct btrfs_file_extent_item);
742
743 type = btrfs_file_extent_type(leaf, extent);
744 if (type == BTRFS_FILE_EXTENT_REG &&
745 btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
746 check_defrag_in_cache(inode, min_key.offset, thresh)) {
747 *off = min_key.offset;
748 btrfs_free_path(path);
749 return 0;
750 }
751
752 if (min_key.offset == (u64)-1)
753 goto none;
754
755 min_key.offset++;
756 btrfs_release_path(path);
757 }
758 none:
759 btrfs_free_path(path);
760 return -ENOENT;
761 }
762
763 static int should_defrag_range(struct inode *inode, u64 start, u64 len,
764 int thresh, u64 *last_len, u64 *skip,
765 u64 *defrag_end)
766 {
767 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
768 struct extent_map *em = NULL;
769 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
770 int ret = 1;
771
772 /*
773 * make sure that once we start defragging an extent, we keep on
774 * defragging it
775 */
776 if (start < *defrag_end)
777 return 1;
778
779 *skip = 0;
780
781 /*
782 * hopefully we have this extent in the tree already, try without
783 * the full extent lock
784 */
785 read_lock(&em_tree->lock);
786 em = lookup_extent_mapping(em_tree, start, len);
787 read_unlock(&em_tree->lock);
788
789 if (!em) {
790 /* get the big lock and read metadata off disk */
791 lock_extent(io_tree, start, start + len - 1, GFP_NOFS);
792 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
793 unlock_extent(io_tree, start, start + len - 1, GFP_NOFS);
794
795 if (IS_ERR(em))
796 return 0;
797 }
798
799 /* this will cover holes, and inline extents */
800 if (em->block_start >= EXTENT_MAP_LAST_BYTE)
801 ret = 0;
802
803 /*
804 * we hit a real extent, if it is big don't bother defragging it again
805 */
806 if ((*last_len == 0 || *last_len >= thresh) && em->len >= thresh)
807 ret = 0;
808
809 /*
810 * last_len ends up being a counter of how many bytes we've defragged.
811 * every time we choose not to defrag an extent, we reset *last_len
812 * so that the next tiny extent will force a defrag.
813 *
814 * The end result of this is that tiny extents before a single big
815 * extent will force at least part of that big extent to be defragged.
816 */
817 if (ret) {
818 *defrag_end = extent_map_end(em);
819 } else {
820 *last_len = 0;
821 *skip = extent_map_end(em);
822 *defrag_end = 0;
823 }
824
825 free_extent_map(em);
826 return ret;
827 }
828
829 /*
830 * it doesn't do much good to defrag one or two pages
831 * at a time. This pulls in a nice chunk of pages
832 * to COW and defrag.
833 *
834 * It also makes sure the delalloc code has enough
835 * dirty data to avoid making new small extents as part
836 * of the defrag
837 *
838 * It's a good idea to start RA on this range
839 * before calling this.
840 */
841 static int cluster_pages_for_defrag(struct inode *inode,
842 struct page **pages,
843 unsigned long start_index,
844 int num_pages)
845 {
846 unsigned long file_end;
847 u64 isize = i_size_read(inode);
848 u64 page_start;
849 u64 page_end;
850 int ret;
851 int i;
852 int i_done;
853 struct btrfs_ordered_extent *ordered;
854 struct extent_state *cached_state = NULL;
855 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
856
857 if (isize == 0)
858 return 0;
859 file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
860
861 mutex_lock(&inode->i_mutex);
862 ret = btrfs_delalloc_reserve_space(inode,
863 num_pages << PAGE_CACHE_SHIFT);
864 mutex_unlock(&inode->i_mutex);
865 if (ret)
866 return ret;
867 again:
868 ret = 0;
869 i_done = 0;
870
871 /* step one, lock all the pages */
872 for (i = 0; i < num_pages; i++) {
873 struct page *page;
874 page = find_or_create_page(inode->i_mapping,
875 start_index + i, mask);
876 if (!page)
877 break;
878
879 if (!PageUptodate(page)) {
880 btrfs_readpage(NULL, page);
881 lock_page(page);
882 if (!PageUptodate(page)) {
883 unlock_page(page);
884 page_cache_release(page);
885 ret = -EIO;
886 break;
887 }
888 }
889 isize = i_size_read(inode);
890 file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
891 if (!isize || page->index > file_end ||
892 page->mapping != inode->i_mapping) {
893 /* whoops, we blew past eof, skip this page */
894 unlock_page(page);
895 page_cache_release(page);
896 break;
897 }
898 pages[i] = page;
899 i_done++;
900 }
901 if (!i_done || ret)
902 goto out;
903
904 if (!(inode->i_sb->s_flags & MS_ACTIVE))
905 goto out;
906
907 /*
908 * so now we have a nice long stream of locked
909 * and up to date pages, lets wait on them
910 */
911 for (i = 0; i < i_done; i++)
912 wait_on_page_writeback(pages[i]);
913
914 page_start = page_offset(pages[0]);
915 page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
916
917 lock_extent_bits(&BTRFS_I(inode)->io_tree,
918 page_start, page_end - 1, 0, &cached_state,
919 GFP_NOFS);
920 ordered = btrfs_lookup_first_ordered_extent(inode, page_end - 1);
921 if (ordered &&
922 ordered->file_offset + ordered->len > page_start &&
923 ordered->file_offset < page_end) {
924 btrfs_put_ordered_extent(ordered);
925 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
926 page_start, page_end - 1,
927 &cached_state, GFP_NOFS);
928 for (i = 0; i < i_done; i++) {
929 unlock_page(pages[i]);
930 page_cache_release(pages[i]);
931 }
932 btrfs_wait_ordered_range(inode, page_start,
933 page_end - page_start);
934 goto again;
935 }
936 if (ordered)
937 btrfs_put_ordered_extent(ordered);
938
939 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
940 page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
941 EXTENT_DO_ACCOUNTING, 0, 0, &cached_state,
942 GFP_NOFS);
943
944 if (i_done != num_pages) {
945 spin_lock(&BTRFS_I(inode)->lock);
946 BTRFS_I(inode)->outstanding_extents++;
947 spin_unlock(&BTRFS_I(inode)->lock);
948 btrfs_delalloc_release_space(inode,
949 (num_pages - i_done) << PAGE_CACHE_SHIFT);
950 }
951
952
953 btrfs_set_extent_delalloc(inode, page_start, page_end - 1,
954 &cached_state);
955
956 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
957 page_start, page_end - 1, &cached_state,
958 GFP_NOFS);
959
960 for (i = 0; i < i_done; i++) {
961 clear_page_dirty_for_io(pages[i]);
962 ClearPageChecked(pages[i]);
963 set_page_extent_mapped(pages[i]);
964 set_page_dirty(pages[i]);
965 unlock_page(pages[i]);
966 page_cache_release(pages[i]);
967 }
968 return i_done;
969 out:
970 for (i = 0; i < i_done; i++) {
971 unlock_page(pages[i]);
972 page_cache_release(pages[i]);
973 }
974 btrfs_delalloc_release_space(inode, num_pages << PAGE_CACHE_SHIFT);
975 return ret;
976
977 }
978
979 int btrfs_defrag_file(struct inode *inode, struct file *file,
980 struct btrfs_ioctl_defrag_range_args *range,
981 u64 newer_than, unsigned long max_to_defrag)
982 {
983 struct btrfs_root *root = BTRFS_I(inode)->root;
984 struct btrfs_super_block *disk_super;
985 struct file_ra_state *ra = NULL;
986 unsigned long last_index;
987 u64 isize = i_size_read(inode);
988 u64 features;
989 u64 last_len = 0;
990 u64 skip = 0;
991 u64 defrag_end = 0;
992 u64 newer_off = range->start;
993 unsigned long i;
994 unsigned long ra_index = 0;
995 int ret;
996 int defrag_count = 0;
997 int compress_type = BTRFS_COMPRESS_ZLIB;
998 int extent_thresh = range->extent_thresh;
999 int max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT;
1000 int cluster = max_cluster;
1001 u64 new_align = ~((u64)128 * 1024 - 1);
1002 struct page **pages = NULL;
1003
1004 if (extent_thresh == 0)
1005 extent_thresh = 256 * 1024;
1006
1007 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1008 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1009 return -EINVAL;
1010 if (range->compress_type)
1011 compress_type = range->compress_type;
1012 }
1013
1014 if (isize == 0)
1015 return 0;
1016
1017 /*
1018 * if we were not given a file, allocate a readahead
1019 * context
1020 */
1021 if (!file) {
1022 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1023 if (!ra)
1024 return -ENOMEM;
1025 file_ra_state_init(ra, inode->i_mapping);
1026 } else {
1027 ra = &file->f_ra;
1028 }
1029
1030 pages = kmalloc(sizeof(struct page *) * max_cluster,
1031 GFP_NOFS);
1032 if (!pages) {
1033 ret = -ENOMEM;
1034 goto out_ra;
1035 }
1036
1037 /* find the last page to defrag */
1038 if (range->start + range->len > range->start) {
1039 last_index = min_t(u64, isize - 1,
1040 range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
1041 } else {
1042 last_index = (isize - 1) >> PAGE_CACHE_SHIFT;
1043 }
1044
1045 if (newer_than) {
1046 ret = find_new_extents(root, inode, newer_than,
1047 &newer_off, 64 * 1024);
1048 if (!ret) {
1049 range->start = newer_off;
1050 /*
1051 * we always align our defrag to help keep
1052 * the extents in the file evenly spaced
1053 */
1054 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1055 } else
1056 goto out_ra;
1057 } else {
1058 i = range->start >> PAGE_CACHE_SHIFT;
1059 }
1060 if (!max_to_defrag)
1061 max_to_defrag = last_index;
1062
1063 /*
1064 * make writeback starts from i, so the defrag range can be
1065 * written sequentially.
1066 */
1067 if (i < inode->i_mapping->writeback_index)
1068 inode->i_mapping->writeback_index = i;
1069
1070 while (i <= last_index && defrag_count < max_to_defrag &&
1071 (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1072 PAGE_CACHE_SHIFT)) {
1073 /*
1074 * make sure we stop running if someone unmounts
1075 * the FS
1076 */
1077 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1078 break;
1079
1080 if (!newer_than &&
1081 !should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
1082 PAGE_CACHE_SIZE,
1083 extent_thresh,
1084 &last_len, &skip,
1085 &defrag_end)) {
1086 unsigned long next;
1087 /*
1088 * the should_defrag function tells us how much to skip
1089 * bump our counter by the suggested amount
1090 */
1091 next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1092 i = max(i + 1, next);
1093 continue;
1094 }
1095
1096 if (!newer_than) {
1097 cluster = (PAGE_CACHE_ALIGN(defrag_end) >>
1098 PAGE_CACHE_SHIFT) - i;
1099 cluster = min(cluster, max_cluster);
1100 } else {
1101 cluster = max_cluster;
1102 }
1103
1104 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1105 BTRFS_I(inode)->force_compress = compress_type;
1106
1107 if (i + cluster > ra_index) {
1108 ra_index = max(i, ra_index);
1109 btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1110 cluster);
1111 ra_index += max_cluster;
1112 }
1113
1114 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1115 if (ret < 0)
1116 goto out_ra;
1117
1118 defrag_count += ret;
1119 balance_dirty_pages_ratelimited_nr(inode->i_mapping, ret);
1120
1121 if (newer_than) {
1122 if (newer_off == (u64)-1)
1123 break;
1124
1125 newer_off = max(newer_off + 1,
1126 (u64)i << PAGE_CACHE_SHIFT);
1127
1128 ret = find_new_extents(root, inode,
1129 newer_than, &newer_off,
1130 64 * 1024);
1131 if (!ret) {
1132 range->start = newer_off;
1133 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1134 } else {
1135 break;
1136 }
1137 } else {
1138 if (ret > 0) {
1139 i += ret;
1140 last_len += ret << PAGE_CACHE_SHIFT;
1141 } else {
1142 i++;
1143 last_len = 0;
1144 }
1145 }
1146 }
1147
1148 if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
1149 filemap_flush(inode->i_mapping);
1150
1151 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1152 /* the filemap_flush will queue IO into the worker threads, but
1153 * we have to make sure the IO is actually started and that
1154 * ordered extents get created before we return
1155 */
1156 atomic_inc(&root->fs_info->async_submit_draining);
1157 while (atomic_read(&root->fs_info->nr_async_submits) ||
1158 atomic_read(&root->fs_info->async_delalloc_pages)) {
1159 wait_event(root->fs_info->async_submit_wait,
1160 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1161 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1162 }
1163 atomic_dec(&root->fs_info->async_submit_draining);
1164
1165 mutex_lock(&inode->i_mutex);
1166 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1167 mutex_unlock(&inode->i_mutex);
1168 }
1169
1170 disk_super = root->fs_info->super_copy;
1171 features = btrfs_super_incompat_flags(disk_super);
1172 if (range->compress_type == BTRFS_COMPRESS_LZO) {
1173 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
1174 btrfs_set_super_incompat_flags(disk_super, features);
1175 }
1176
1177 ret = defrag_count;
1178
1179 out_ra:
1180 if (!file)
1181 kfree(ra);
1182 kfree(pages);
1183 return ret;
1184 }
1185
1186 static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
1187 void __user *arg)
1188 {
1189 u64 new_size;
1190 u64 old_size;
1191 u64 devid = 1;
1192 struct btrfs_ioctl_vol_args *vol_args;
1193 struct btrfs_trans_handle *trans;
1194 struct btrfs_device *device = NULL;
1195 char *sizestr;
1196 char *devstr = NULL;
1197 int ret = 0;
1198 int mod = 0;
1199
1200 if (root->fs_info->sb->s_flags & MS_RDONLY)
1201 return -EROFS;
1202
1203 if (!capable(CAP_SYS_ADMIN))
1204 return -EPERM;
1205
1206 vol_args = memdup_user(arg, sizeof(*vol_args));
1207 if (IS_ERR(vol_args))
1208 return PTR_ERR(vol_args);
1209
1210 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1211
1212 mutex_lock(&root->fs_info->volume_mutex);
1213 sizestr = vol_args->name;
1214 devstr = strchr(sizestr, ':');
1215 if (devstr) {
1216 char *end;
1217 sizestr = devstr + 1;
1218 *devstr = '\0';
1219 devstr = vol_args->name;
1220 devid = simple_strtoull(devstr, &end, 10);
1221 printk(KERN_INFO "btrfs: resizing devid %llu\n",
1222 (unsigned long long)devid);
1223 }
1224 device = btrfs_find_device(root, devid, NULL, NULL);
1225 if (!device) {
1226 printk(KERN_INFO "btrfs: resizer unable to find device %llu\n",
1227 (unsigned long long)devid);
1228 ret = -EINVAL;
1229 goto out_unlock;
1230 }
1231 if (!strcmp(sizestr, "max"))
1232 new_size = device->bdev->bd_inode->i_size;
1233 else {
1234 if (sizestr[0] == '-') {
1235 mod = -1;
1236 sizestr++;
1237 } else if (sizestr[0] == '+') {
1238 mod = 1;
1239 sizestr++;
1240 }
1241 new_size = memparse(sizestr, NULL);
1242 if (new_size == 0) {
1243 ret = -EINVAL;
1244 goto out_unlock;
1245 }
1246 }
1247
1248 old_size = device->total_bytes;
1249
1250 if (mod < 0) {
1251 if (new_size > old_size) {
1252 ret = -EINVAL;
1253 goto out_unlock;
1254 }
1255 new_size = old_size - new_size;
1256 } else if (mod > 0) {
1257 new_size = old_size + new_size;
1258 }
1259
1260 if (new_size < 256 * 1024 * 1024) {
1261 ret = -EINVAL;
1262 goto out_unlock;
1263 }
1264 if (new_size > device->bdev->bd_inode->i_size) {
1265 ret = -EFBIG;
1266 goto out_unlock;
1267 }
1268
1269 do_div(new_size, root->sectorsize);
1270 new_size *= root->sectorsize;
1271
1272 printk(KERN_INFO "btrfs: new size for %s is %llu\n",
1273 device->name, (unsigned long long)new_size);
1274
1275 if (new_size > old_size) {
1276 trans = btrfs_start_transaction(root, 0);
1277 if (IS_ERR(trans)) {
1278 ret = PTR_ERR(trans);
1279 goto out_unlock;
1280 }
1281 ret = btrfs_grow_device(trans, device, new_size);
1282 btrfs_commit_transaction(trans, root);
1283 } else if (new_size < old_size) {
1284 ret = btrfs_shrink_device(device, new_size);
1285 }
1286
1287 out_unlock:
1288 mutex_unlock(&root->fs_info->volume_mutex);
1289 kfree(vol_args);
1290 return ret;
1291 }
1292
1293 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1294 char *name,
1295 unsigned long fd,
1296 int subvol,
1297 u64 *transid,
1298 bool readonly)
1299 {
1300 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
1301 struct file *src_file;
1302 int namelen;
1303 int ret = 0;
1304
1305 if (root->fs_info->sb->s_flags & MS_RDONLY)
1306 return -EROFS;
1307
1308 namelen = strlen(name);
1309 if (strchr(name, '/')) {
1310 ret = -EINVAL;
1311 goto out;
1312 }
1313
1314 if (subvol) {
1315 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1316 NULL, transid, readonly);
1317 } else {
1318 struct inode *src_inode;
1319 src_file = fget(fd);
1320 if (!src_file) {
1321 ret = -EINVAL;
1322 goto out;
1323 }
1324
1325 src_inode = src_file->f_path.dentry->d_inode;
1326 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
1327 printk(KERN_INFO "btrfs: Snapshot src from "
1328 "another FS\n");
1329 ret = -EINVAL;
1330 } else if (!inode_owner_or_capable(src_inode)) {
1331 /*
1332 * Subvolume creation is not restricted, but snapshots
1333 * are limited to own subvolumes only
1334 */
1335 ret = -EPERM;
1336 } else {
1337 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1338 BTRFS_I(src_inode)->root,
1339 transid, readonly);
1340 }
1341 fput(src_file);
1342 }
1343 out:
1344 return ret;
1345 }
1346
1347 static noinline int btrfs_ioctl_snap_create(struct file *file,
1348 void __user *arg, int subvol)
1349 {
1350 struct btrfs_ioctl_vol_args *vol_args;
1351 int ret;
1352
1353 vol_args = memdup_user(arg, sizeof(*vol_args));
1354 if (IS_ERR(vol_args))
1355 return PTR_ERR(vol_args);
1356 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1357
1358 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1359 vol_args->fd, subvol,
1360 NULL, false);
1361
1362 kfree(vol_args);
1363 return ret;
1364 }
1365
1366 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1367 void __user *arg, int subvol)
1368 {
1369 struct btrfs_ioctl_vol_args_v2 *vol_args;
1370 int ret;
1371 u64 transid = 0;
1372 u64 *ptr = NULL;
1373 bool readonly = false;
1374
1375 vol_args = memdup_user(arg, sizeof(*vol_args));
1376 if (IS_ERR(vol_args))
1377 return PTR_ERR(vol_args);
1378 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1379
1380 if (vol_args->flags &
1381 ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY)) {
1382 ret = -EOPNOTSUPP;
1383 goto out;
1384 }
1385
1386 if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1387 ptr = &transid;
1388 if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1389 readonly = true;
1390
1391 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1392 vol_args->fd, subvol,
1393 ptr, readonly);
1394
1395 if (ret == 0 && ptr &&
1396 copy_to_user(arg +
1397 offsetof(struct btrfs_ioctl_vol_args_v2,
1398 transid), ptr, sizeof(*ptr)))
1399 ret = -EFAULT;
1400 out:
1401 kfree(vol_args);
1402 return ret;
1403 }
1404
1405 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1406 void __user *arg)
1407 {
1408 struct inode *inode = fdentry(file)->d_inode;
1409 struct btrfs_root *root = BTRFS_I(inode)->root;
1410 int ret = 0;
1411 u64 flags = 0;
1412
1413 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1414 return -EINVAL;
1415
1416 down_read(&root->fs_info->subvol_sem);
1417 if (btrfs_root_readonly(root))
1418 flags |= BTRFS_SUBVOL_RDONLY;
1419 up_read(&root->fs_info->subvol_sem);
1420
1421 if (copy_to_user(arg, &flags, sizeof(flags)))
1422 ret = -EFAULT;
1423
1424 return ret;
1425 }
1426
1427 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1428 void __user *arg)
1429 {
1430 struct inode *inode = fdentry(file)->d_inode;
1431 struct btrfs_root *root = BTRFS_I(inode)->root;
1432 struct btrfs_trans_handle *trans;
1433 u64 root_flags;
1434 u64 flags;
1435 int ret = 0;
1436
1437 if (root->fs_info->sb->s_flags & MS_RDONLY)
1438 return -EROFS;
1439
1440 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1441 return -EINVAL;
1442
1443 if (copy_from_user(&flags, arg, sizeof(flags)))
1444 return -EFAULT;
1445
1446 if (flags & BTRFS_SUBVOL_CREATE_ASYNC)
1447 return -EINVAL;
1448
1449 if (flags & ~BTRFS_SUBVOL_RDONLY)
1450 return -EOPNOTSUPP;
1451
1452 if (!inode_owner_or_capable(inode))
1453 return -EACCES;
1454
1455 down_write(&root->fs_info->subvol_sem);
1456
1457 /* nothing to do */
1458 if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1459 goto out;
1460
1461 root_flags = btrfs_root_flags(&root->root_item);
1462 if (flags & BTRFS_SUBVOL_RDONLY)
1463 btrfs_set_root_flags(&root->root_item,
1464 root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1465 else
1466 btrfs_set_root_flags(&root->root_item,
1467 root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1468
1469 trans = btrfs_start_transaction(root, 1);
1470 if (IS_ERR(trans)) {
1471 ret = PTR_ERR(trans);
1472 goto out_reset;
1473 }
1474
1475 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1476 &root->root_key, &root->root_item);
1477
1478 btrfs_commit_transaction(trans, root);
1479 out_reset:
1480 if (ret)
1481 btrfs_set_root_flags(&root->root_item, root_flags);
1482 out:
1483 up_write(&root->fs_info->subvol_sem);
1484 return ret;
1485 }
1486
1487 /*
1488 * helper to check if the subvolume references other subvolumes
1489 */
1490 static noinline int may_destroy_subvol(struct btrfs_root *root)
1491 {
1492 struct btrfs_path *path;
1493 struct btrfs_key key;
1494 int ret;
1495
1496 path = btrfs_alloc_path();
1497 if (!path)
1498 return -ENOMEM;
1499
1500 key.objectid = root->root_key.objectid;
1501 key.type = BTRFS_ROOT_REF_KEY;
1502 key.offset = (u64)-1;
1503
1504 ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1505 &key, path, 0, 0);
1506 if (ret < 0)
1507 goto out;
1508 BUG_ON(ret == 0);
1509
1510 ret = 0;
1511 if (path->slots[0] > 0) {
1512 path->slots[0]--;
1513 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1514 if (key.objectid == root->root_key.objectid &&
1515 key.type == BTRFS_ROOT_REF_KEY)
1516 ret = -ENOTEMPTY;
1517 }
1518 out:
1519 btrfs_free_path(path);
1520 return ret;
1521 }
1522
1523 static noinline int key_in_sk(struct btrfs_key *key,
1524 struct btrfs_ioctl_search_key *sk)
1525 {
1526 struct btrfs_key test;
1527 int ret;
1528
1529 test.objectid = sk->min_objectid;
1530 test.type = sk->min_type;
1531 test.offset = sk->min_offset;
1532
1533 ret = btrfs_comp_cpu_keys(key, &test);
1534 if (ret < 0)
1535 return 0;
1536
1537 test.objectid = sk->max_objectid;
1538 test.type = sk->max_type;
1539 test.offset = sk->max_offset;
1540
1541 ret = btrfs_comp_cpu_keys(key, &test);
1542 if (ret > 0)
1543 return 0;
1544 return 1;
1545 }
1546
1547 static noinline int copy_to_sk(struct btrfs_root *root,
1548 struct btrfs_path *path,
1549 struct btrfs_key *key,
1550 struct btrfs_ioctl_search_key *sk,
1551 char *buf,
1552 unsigned long *sk_offset,
1553 int *num_found)
1554 {
1555 u64 found_transid;
1556 struct extent_buffer *leaf;
1557 struct btrfs_ioctl_search_header sh;
1558 unsigned long item_off;
1559 unsigned long item_len;
1560 int nritems;
1561 int i;
1562 int slot;
1563 int ret = 0;
1564
1565 leaf = path->nodes[0];
1566 slot = path->slots[0];
1567 nritems = btrfs_header_nritems(leaf);
1568
1569 if (btrfs_header_generation(leaf) > sk->max_transid) {
1570 i = nritems;
1571 goto advance_key;
1572 }
1573 found_transid = btrfs_header_generation(leaf);
1574
1575 for (i = slot; i < nritems; i++) {
1576 item_off = btrfs_item_ptr_offset(leaf, i);
1577 item_len = btrfs_item_size_nr(leaf, i);
1578
1579 btrfs_item_key_to_cpu(leaf, key, i);
1580 if (!key_in_sk(key, sk))
1581 continue;
1582
1583 if (sizeof(sh) + item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1584 item_len = 0;
1585
1586 if (sizeof(sh) + item_len + *sk_offset >
1587 BTRFS_SEARCH_ARGS_BUFSIZE) {
1588 ret = 1;
1589 goto overflow;
1590 }
1591
1592 sh.objectid = key->objectid;
1593 sh.offset = key->offset;
1594 sh.type = key->type;
1595 sh.len = item_len;
1596 sh.transid = found_transid;
1597
1598 /* copy search result header */
1599 memcpy(buf + *sk_offset, &sh, sizeof(sh));
1600 *sk_offset += sizeof(sh);
1601
1602 if (item_len) {
1603 char *p = buf + *sk_offset;
1604 /* copy the item */
1605 read_extent_buffer(leaf, p,
1606 item_off, item_len);
1607 *sk_offset += item_len;
1608 }
1609 (*num_found)++;
1610
1611 if (*num_found >= sk->nr_items)
1612 break;
1613 }
1614 advance_key:
1615 ret = 0;
1616 if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1617 key->offset++;
1618 else if (key->type < (u8)-1 && key->type < sk->max_type) {
1619 key->offset = 0;
1620 key->type++;
1621 } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1622 key->offset = 0;
1623 key->type = 0;
1624 key->objectid++;
1625 } else
1626 ret = 1;
1627 overflow:
1628 return ret;
1629 }
1630
1631 static noinline int search_ioctl(struct inode *inode,
1632 struct btrfs_ioctl_search_args *args)
1633 {
1634 struct btrfs_root *root;
1635 struct btrfs_key key;
1636 struct btrfs_key max_key;
1637 struct btrfs_path *path;
1638 struct btrfs_ioctl_search_key *sk = &args->key;
1639 struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1640 int ret;
1641 int num_found = 0;
1642 unsigned long sk_offset = 0;
1643
1644 path = btrfs_alloc_path();
1645 if (!path)
1646 return -ENOMEM;
1647
1648 if (sk->tree_id == 0) {
1649 /* search the root of the inode that was passed */
1650 root = BTRFS_I(inode)->root;
1651 } else {
1652 key.objectid = sk->tree_id;
1653 key.type = BTRFS_ROOT_ITEM_KEY;
1654 key.offset = (u64)-1;
1655 root = btrfs_read_fs_root_no_name(info, &key);
1656 if (IS_ERR(root)) {
1657 printk(KERN_ERR "could not find root %llu\n",
1658 sk->tree_id);
1659 btrfs_free_path(path);
1660 return -ENOENT;
1661 }
1662 }
1663
1664 key.objectid = sk->min_objectid;
1665 key.type = sk->min_type;
1666 key.offset = sk->min_offset;
1667
1668 max_key.objectid = sk->max_objectid;
1669 max_key.type = sk->max_type;
1670 max_key.offset = sk->max_offset;
1671
1672 path->keep_locks = 1;
1673
1674 while(1) {
1675 ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1676 sk->min_transid);
1677 if (ret != 0) {
1678 if (ret > 0)
1679 ret = 0;
1680 goto err;
1681 }
1682 ret = copy_to_sk(root, path, &key, sk, args->buf,
1683 &sk_offset, &num_found);
1684 btrfs_release_path(path);
1685 if (ret || num_found >= sk->nr_items)
1686 break;
1687
1688 }
1689 ret = 0;
1690 err:
1691 sk->nr_items = num_found;
1692 btrfs_free_path(path);
1693 return ret;
1694 }
1695
1696 static noinline int btrfs_ioctl_tree_search(struct file *file,
1697 void __user *argp)
1698 {
1699 struct btrfs_ioctl_search_args *args;
1700 struct inode *inode;
1701 int ret;
1702
1703 if (!capable(CAP_SYS_ADMIN))
1704 return -EPERM;
1705
1706 args = memdup_user(argp, sizeof(*args));
1707 if (IS_ERR(args))
1708 return PTR_ERR(args);
1709
1710 inode = fdentry(file)->d_inode;
1711 ret = search_ioctl(inode, args);
1712 if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1713 ret = -EFAULT;
1714 kfree(args);
1715 return ret;
1716 }
1717
1718 /*
1719 * Search INODE_REFs to identify path name of 'dirid' directory
1720 * in a 'tree_id' tree. and sets path name to 'name'.
1721 */
1722 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1723 u64 tree_id, u64 dirid, char *name)
1724 {
1725 struct btrfs_root *root;
1726 struct btrfs_key key;
1727 char *ptr;
1728 int ret = -1;
1729 int slot;
1730 int len;
1731 int total_len = 0;
1732 struct btrfs_inode_ref *iref;
1733 struct extent_buffer *l;
1734 struct btrfs_path *path;
1735
1736 if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1737 name[0]='\0';
1738 return 0;
1739 }
1740
1741 path = btrfs_alloc_path();
1742 if (!path)
1743 return -ENOMEM;
1744
1745 ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1746
1747 key.objectid = tree_id;
1748 key.type = BTRFS_ROOT_ITEM_KEY;
1749 key.offset = (u64)-1;
1750 root = btrfs_read_fs_root_no_name(info, &key);
1751 if (IS_ERR(root)) {
1752 printk(KERN_ERR "could not find root %llu\n", tree_id);
1753 ret = -ENOENT;
1754 goto out;
1755 }
1756
1757 key.objectid = dirid;
1758 key.type = BTRFS_INODE_REF_KEY;
1759 key.offset = (u64)-1;
1760
1761 while(1) {
1762 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1763 if (ret < 0)
1764 goto out;
1765
1766 l = path->nodes[0];
1767 slot = path->slots[0];
1768 if (ret > 0 && slot > 0)
1769 slot--;
1770 btrfs_item_key_to_cpu(l, &key, slot);
1771
1772 if (ret > 0 && (key.objectid != dirid ||
1773 key.type != BTRFS_INODE_REF_KEY)) {
1774 ret = -ENOENT;
1775 goto out;
1776 }
1777
1778 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1779 len = btrfs_inode_ref_name_len(l, iref);
1780 ptr -= len + 1;
1781 total_len += len + 1;
1782 if (ptr < name)
1783 goto out;
1784
1785 *(ptr + len) = '/';
1786 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1787
1788 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1789 break;
1790
1791 btrfs_release_path(path);
1792 key.objectid = key.offset;
1793 key.offset = (u64)-1;
1794 dirid = key.objectid;
1795 }
1796 if (ptr < name)
1797 goto out;
1798 memmove(name, ptr, total_len);
1799 name[total_len]='\0';
1800 ret = 0;
1801 out:
1802 btrfs_free_path(path);
1803 return ret;
1804 }
1805
1806 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1807 void __user *argp)
1808 {
1809 struct btrfs_ioctl_ino_lookup_args *args;
1810 struct inode *inode;
1811 int ret;
1812
1813 if (!capable(CAP_SYS_ADMIN))
1814 return -EPERM;
1815
1816 args = memdup_user(argp, sizeof(*args));
1817 if (IS_ERR(args))
1818 return PTR_ERR(args);
1819
1820 inode = fdentry(file)->d_inode;
1821
1822 if (args->treeid == 0)
1823 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
1824
1825 ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
1826 args->treeid, args->objectid,
1827 args->name);
1828
1829 if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1830 ret = -EFAULT;
1831
1832 kfree(args);
1833 return ret;
1834 }
1835
1836 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
1837 void __user *arg)
1838 {
1839 struct dentry *parent = fdentry(file);
1840 struct dentry *dentry;
1841 struct inode *dir = parent->d_inode;
1842 struct inode *inode;
1843 struct btrfs_root *root = BTRFS_I(dir)->root;
1844 struct btrfs_root *dest = NULL;
1845 struct btrfs_ioctl_vol_args *vol_args;
1846 struct btrfs_trans_handle *trans;
1847 int namelen;
1848 int ret;
1849 int err = 0;
1850
1851 vol_args = memdup_user(arg, sizeof(*vol_args));
1852 if (IS_ERR(vol_args))
1853 return PTR_ERR(vol_args);
1854
1855 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1856 namelen = strlen(vol_args->name);
1857 if (strchr(vol_args->name, '/') ||
1858 strncmp(vol_args->name, "..", namelen) == 0) {
1859 err = -EINVAL;
1860 goto out;
1861 }
1862
1863 err = mnt_want_write(file->f_path.mnt);
1864 if (err)
1865 goto out;
1866
1867 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
1868 dentry = lookup_one_len(vol_args->name, parent, namelen);
1869 if (IS_ERR(dentry)) {
1870 err = PTR_ERR(dentry);
1871 goto out_unlock_dir;
1872 }
1873
1874 if (!dentry->d_inode) {
1875 err = -ENOENT;
1876 goto out_dput;
1877 }
1878
1879 inode = dentry->d_inode;
1880 dest = BTRFS_I(inode)->root;
1881 if (!capable(CAP_SYS_ADMIN)){
1882 /*
1883 * Regular user. Only allow this with a special mount
1884 * option, when the user has write+exec access to the
1885 * subvol root, and when rmdir(2) would have been
1886 * allowed.
1887 *
1888 * Note that this is _not_ check that the subvol is
1889 * empty or doesn't contain data that we wouldn't
1890 * otherwise be able to delete.
1891 *
1892 * Users who want to delete empty subvols should try
1893 * rmdir(2).
1894 */
1895 err = -EPERM;
1896 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1897 goto out_dput;
1898
1899 /*
1900 * Do not allow deletion if the parent dir is the same
1901 * as the dir to be deleted. That means the ioctl
1902 * must be called on the dentry referencing the root
1903 * of the subvol, not a random directory contained
1904 * within it.
1905 */
1906 err = -EINVAL;
1907 if (root == dest)
1908 goto out_dput;
1909
1910 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
1911 if (err)
1912 goto out_dput;
1913
1914 /* check if subvolume may be deleted by a non-root user */
1915 err = btrfs_may_delete(dir, dentry, 1);
1916 if (err)
1917 goto out_dput;
1918 }
1919
1920 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1921 err = -EINVAL;
1922 goto out_dput;
1923 }
1924
1925 mutex_lock(&inode->i_mutex);
1926 err = d_invalidate(dentry);
1927 if (err)
1928 goto out_unlock;
1929
1930 down_write(&root->fs_info->subvol_sem);
1931
1932 err = may_destroy_subvol(dest);
1933 if (err)
1934 goto out_up_write;
1935
1936 trans = btrfs_start_transaction(root, 0);
1937 if (IS_ERR(trans)) {
1938 err = PTR_ERR(trans);
1939 goto out_up_write;
1940 }
1941 trans->block_rsv = &root->fs_info->global_block_rsv;
1942
1943 ret = btrfs_unlink_subvol(trans, root, dir,
1944 dest->root_key.objectid,
1945 dentry->d_name.name,
1946 dentry->d_name.len);
1947 BUG_ON(ret);
1948
1949 btrfs_record_root_in_trans(trans, dest);
1950
1951 memset(&dest->root_item.drop_progress, 0,
1952 sizeof(dest->root_item.drop_progress));
1953 dest->root_item.drop_level = 0;
1954 btrfs_set_root_refs(&dest->root_item, 0);
1955
1956 if (!xchg(&dest->orphan_item_inserted, 1)) {
1957 ret = btrfs_insert_orphan_item(trans,
1958 root->fs_info->tree_root,
1959 dest->root_key.objectid);
1960 BUG_ON(ret);
1961 }
1962
1963 ret = btrfs_end_transaction(trans, root);
1964 BUG_ON(ret);
1965 inode->i_flags |= S_DEAD;
1966 out_up_write:
1967 up_write(&root->fs_info->subvol_sem);
1968 out_unlock:
1969 mutex_unlock(&inode->i_mutex);
1970 if (!err) {
1971 shrink_dcache_sb(root->fs_info->sb);
1972 btrfs_invalidate_inodes(dest);
1973 d_delete(dentry);
1974 }
1975 out_dput:
1976 dput(dentry);
1977 out_unlock_dir:
1978 mutex_unlock(&dir->i_mutex);
1979 mnt_drop_write(file->f_path.mnt);
1980 out:
1981 kfree(vol_args);
1982 return err;
1983 }
1984
1985 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
1986 {
1987 struct inode *inode = fdentry(file)->d_inode;
1988 struct btrfs_root *root = BTRFS_I(inode)->root;
1989 struct btrfs_ioctl_defrag_range_args *range;
1990 int ret;
1991
1992 if (btrfs_root_readonly(root))
1993 return -EROFS;
1994
1995 ret = mnt_want_write(file->f_path.mnt);
1996 if (ret)
1997 return ret;
1998
1999 switch (inode->i_mode & S_IFMT) {
2000 case S_IFDIR:
2001 if (!capable(CAP_SYS_ADMIN)) {
2002 ret = -EPERM;
2003 goto out;
2004 }
2005 ret = btrfs_defrag_root(root, 0);
2006 if (ret)
2007 goto out;
2008 ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
2009 break;
2010 case S_IFREG:
2011 if (!(file->f_mode & FMODE_WRITE)) {
2012 ret = -EINVAL;
2013 goto out;
2014 }
2015
2016 range = kzalloc(sizeof(*range), GFP_KERNEL);
2017 if (!range) {
2018 ret = -ENOMEM;
2019 goto out;
2020 }
2021
2022 if (argp) {
2023 if (copy_from_user(range, argp,
2024 sizeof(*range))) {
2025 ret = -EFAULT;
2026 kfree(range);
2027 goto out;
2028 }
2029 /* compression requires us to start the IO */
2030 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2031 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2032 range->extent_thresh = (u32)-1;
2033 }
2034 } else {
2035 /* the rest are all set to zero by kzalloc */
2036 range->len = (u64)-1;
2037 }
2038 ret = btrfs_defrag_file(fdentry(file)->d_inode, file,
2039 range, 0, 0);
2040 if (ret > 0)
2041 ret = 0;
2042 kfree(range);
2043 break;
2044 default:
2045 ret = -EINVAL;
2046 }
2047 out:
2048 mnt_drop_write(file->f_path.mnt);
2049 return ret;
2050 }
2051
2052 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2053 {
2054 struct btrfs_ioctl_vol_args *vol_args;
2055 int ret;
2056
2057 if (!capable(CAP_SYS_ADMIN))
2058 return -EPERM;
2059
2060 vol_args = memdup_user(arg, sizeof(*vol_args));
2061 if (IS_ERR(vol_args))
2062 return PTR_ERR(vol_args);
2063
2064 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2065 ret = btrfs_init_new_device(root, vol_args->name);
2066
2067 kfree(vol_args);
2068 return ret;
2069 }
2070
2071 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
2072 {
2073 struct btrfs_ioctl_vol_args *vol_args;
2074 int ret;
2075
2076 if (!capable(CAP_SYS_ADMIN))
2077 return -EPERM;
2078
2079 if (root->fs_info->sb->s_flags & MS_RDONLY)
2080 return -EROFS;
2081
2082 vol_args = memdup_user(arg, sizeof(*vol_args));
2083 if (IS_ERR(vol_args))
2084 return PTR_ERR(vol_args);
2085
2086 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2087 ret = btrfs_rm_device(root, vol_args->name);
2088
2089 kfree(vol_args);
2090 return ret;
2091 }
2092
2093 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2094 {
2095 struct btrfs_ioctl_fs_info_args *fi_args;
2096 struct btrfs_device *device;
2097 struct btrfs_device *next;
2098 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2099 int ret = 0;
2100
2101 if (!capable(CAP_SYS_ADMIN))
2102 return -EPERM;
2103
2104 fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2105 if (!fi_args)
2106 return -ENOMEM;
2107
2108 fi_args->num_devices = fs_devices->num_devices;
2109 memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2110
2111 mutex_lock(&fs_devices->device_list_mutex);
2112 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
2113 if (device->devid > fi_args->max_id)
2114 fi_args->max_id = device->devid;
2115 }
2116 mutex_unlock(&fs_devices->device_list_mutex);
2117
2118 if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2119 ret = -EFAULT;
2120
2121 kfree(fi_args);
2122 return ret;
2123 }
2124
2125 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2126 {
2127 struct btrfs_ioctl_dev_info_args *di_args;
2128 struct btrfs_device *dev;
2129 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2130 int ret = 0;
2131 char *s_uuid = NULL;
2132 char empty_uuid[BTRFS_UUID_SIZE] = {0};
2133
2134 if (!capable(CAP_SYS_ADMIN))
2135 return -EPERM;
2136
2137 di_args = memdup_user(arg, sizeof(*di_args));
2138 if (IS_ERR(di_args))
2139 return PTR_ERR(di_args);
2140
2141 if (memcmp(empty_uuid, di_args->uuid, BTRFS_UUID_SIZE) != 0)
2142 s_uuid = di_args->uuid;
2143
2144 mutex_lock(&fs_devices->device_list_mutex);
2145 dev = btrfs_find_device(root, di_args->devid, s_uuid, NULL);
2146 mutex_unlock(&fs_devices->device_list_mutex);
2147
2148 if (!dev) {
2149 ret = -ENODEV;
2150 goto out;
2151 }
2152
2153 di_args->devid = dev->devid;
2154 di_args->bytes_used = dev->bytes_used;
2155 di_args->total_bytes = dev->total_bytes;
2156 memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2157 strncpy(di_args->path, dev->name, sizeof(di_args->path));
2158
2159 out:
2160 if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2161 ret = -EFAULT;
2162
2163 kfree(di_args);
2164 return ret;
2165 }
2166
2167 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
2168 u64 off, u64 olen, u64 destoff)
2169 {
2170 struct inode *inode = fdentry(file)->d_inode;
2171 struct btrfs_root *root = BTRFS_I(inode)->root;
2172 struct file *src_file;
2173 struct inode *src;
2174 struct btrfs_trans_handle *trans;
2175 struct btrfs_path *path;
2176 struct extent_buffer *leaf;
2177 char *buf;
2178 struct btrfs_key key;
2179 u32 nritems;
2180 int slot;
2181 int ret;
2182 u64 len = olen;
2183 u64 bs = root->fs_info->sb->s_blocksize;
2184 u64 hint_byte;
2185
2186 /*
2187 * TODO:
2188 * - split compressed inline extents. annoying: we need to
2189 * decompress into destination's address_space (the file offset
2190 * may change, so source mapping won't do), then recompress (or
2191 * otherwise reinsert) a subrange.
2192 * - allow ranges within the same file to be cloned (provided
2193 * they don't overlap)?
2194 */
2195
2196 /* the destination must be opened for writing */
2197 if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
2198 return -EINVAL;
2199
2200 if (btrfs_root_readonly(root))
2201 return -EROFS;
2202
2203 ret = mnt_want_write(file->f_path.mnt);
2204 if (ret)
2205 return ret;
2206
2207 src_file = fget(srcfd);
2208 if (!src_file) {
2209 ret = -EBADF;
2210 goto out_drop_write;
2211 }
2212
2213 src = src_file->f_dentry->d_inode;
2214
2215 ret = -EINVAL;
2216 if (src == inode)
2217 goto out_fput;
2218
2219 /* the src must be open for reading */
2220 if (!(src_file->f_mode & FMODE_READ))
2221 goto out_fput;
2222
2223 /* don't make the dst file partly checksummed */
2224 if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
2225 (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
2226 goto out_fput;
2227
2228 ret = -EISDIR;
2229 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
2230 goto out_fput;
2231
2232 ret = -EXDEV;
2233 if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
2234 goto out_fput;
2235
2236 ret = -ENOMEM;
2237 buf = vmalloc(btrfs_level_size(root, 0));
2238 if (!buf)
2239 goto out_fput;
2240
2241 path = btrfs_alloc_path();
2242 if (!path) {
2243 vfree(buf);
2244 goto out_fput;
2245 }
2246 path->reada = 2;
2247
2248 if (inode < src) {
2249 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
2250 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
2251 } else {
2252 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
2253 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
2254 }
2255
2256 /* determine range to clone */
2257 ret = -EINVAL;
2258 if (off + len > src->i_size || off + len < off)
2259 goto out_unlock;
2260 if (len == 0)
2261 olen = len = src->i_size - off;
2262 /* if we extend to eof, continue to block boundary */
2263 if (off + len == src->i_size)
2264 len = ALIGN(src->i_size, bs) - off;
2265
2266 /* verify the end result is block aligned */
2267 if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
2268 !IS_ALIGNED(destoff, bs))
2269 goto out_unlock;
2270
2271 if (destoff > inode->i_size) {
2272 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
2273 if (ret)
2274 goto out_unlock;
2275 }
2276
2277 /* truncate page cache pages from target inode range */
2278 truncate_inode_pages_range(&inode->i_data, destoff,
2279 PAGE_CACHE_ALIGN(destoff + len) - 1);
2280
2281 /* do any pending delalloc/csum calc on src, one way or
2282 another, and lock file content */
2283 while (1) {
2284 struct btrfs_ordered_extent *ordered;
2285 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2286 ordered = btrfs_lookup_first_ordered_extent(src, off+len);
2287 if (!ordered &&
2288 !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len,
2289 EXTENT_DELALLOC, 0, NULL))
2290 break;
2291 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2292 if (ordered)
2293 btrfs_put_ordered_extent(ordered);
2294 btrfs_wait_ordered_range(src, off, len);
2295 }
2296
2297 /* clone data */
2298 key.objectid = btrfs_ino(src);
2299 key.type = BTRFS_EXTENT_DATA_KEY;
2300 key.offset = 0;
2301
2302 while (1) {
2303 /*
2304 * note the key will change type as we walk through the
2305 * tree.
2306 */
2307 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2308 if (ret < 0)
2309 goto out;
2310
2311 nritems = btrfs_header_nritems(path->nodes[0]);
2312 if (path->slots[0] >= nritems) {
2313 ret = btrfs_next_leaf(root, path);
2314 if (ret < 0)
2315 goto out;
2316 if (ret > 0)
2317 break;
2318 nritems = btrfs_header_nritems(path->nodes[0]);
2319 }
2320 leaf = path->nodes[0];
2321 slot = path->slots[0];
2322
2323 btrfs_item_key_to_cpu(leaf, &key, slot);
2324 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
2325 key.objectid != btrfs_ino(src))
2326 break;
2327
2328 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
2329 struct btrfs_file_extent_item *extent;
2330 int type;
2331 u32 size;
2332 struct btrfs_key new_key;
2333 u64 disko = 0, diskl = 0;
2334 u64 datao = 0, datal = 0;
2335 u8 comp;
2336 u64 endoff;
2337
2338 size = btrfs_item_size_nr(leaf, slot);
2339 read_extent_buffer(leaf, buf,
2340 btrfs_item_ptr_offset(leaf, slot),
2341 size);
2342
2343 extent = btrfs_item_ptr(leaf, slot,
2344 struct btrfs_file_extent_item);
2345 comp = btrfs_file_extent_compression(leaf, extent);
2346 type = btrfs_file_extent_type(leaf, extent);
2347 if (type == BTRFS_FILE_EXTENT_REG ||
2348 type == BTRFS_FILE_EXTENT_PREALLOC) {
2349 disko = btrfs_file_extent_disk_bytenr(leaf,
2350 extent);
2351 diskl = btrfs_file_extent_disk_num_bytes(leaf,
2352 extent);
2353 datao = btrfs_file_extent_offset(leaf, extent);
2354 datal = btrfs_file_extent_num_bytes(leaf,
2355 extent);
2356 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2357 /* take upper bound, may be compressed */
2358 datal = btrfs_file_extent_ram_bytes(leaf,
2359 extent);
2360 }
2361 btrfs_release_path(path);
2362
2363 if (key.offset + datal <= off ||
2364 key.offset >= off+len)
2365 goto next;
2366
2367 memcpy(&new_key, &key, sizeof(new_key));
2368 new_key.objectid = btrfs_ino(inode);
2369 if (off <= key.offset)
2370 new_key.offset = key.offset + destoff - off;
2371 else
2372 new_key.offset = destoff;
2373
2374 /*
2375 * 1 - adjusting old extent (we may have to split it)
2376 * 1 - add new extent
2377 * 1 - inode update
2378 */
2379 trans = btrfs_start_transaction(root, 3);
2380 if (IS_ERR(trans)) {
2381 ret = PTR_ERR(trans);
2382 goto out;
2383 }
2384
2385 if (type == BTRFS_FILE_EXTENT_REG ||
2386 type == BTRFS_FILE_EXTENT_PREALLOC) {
2387 /*
2388 * a | --- range to clone ---| b
2389 * | ------------- extent ------------- |
2390 */
2391
2392 /* substract range b */
2393 if (key.offset + datal > off + len)
2394 datal = off + len - key.offset;
2395
2396 /* substract range a */
2397 if (off > key.offset) {
2398 datao += off - key.offset;
2399 datal -= off - key.offset;
2400 }
2401
2402 ret = btrfs_drop_extents(trans, inode,
2403 new_key.offset,
2404 new_key.offset + datal,
2405 &hint_byte, 1);
2406 BUG_ON(ret);
2407
2408 ret = btrfs_insert_empty_item(trans, root, path,
2409 &new_key, size);
2410 BUG_ON(ret);
2411
2412 leaf = path->nodes[0];
2413 slot = path->slots[0];
2414 write_extent_buffer(leaf, buf,
2415 btrfs_item_ptr_offset(leaf, slot),
2416 size);
2417
2418 extent = btrfs_item_ptr(leaf, slot,
2419 struct btrfs_file_extent_item);
2420
2421 /* disko == 0 means it's a hole */
2422 if (!disko)
2423 datao = 0;
2424
2425 btrfs_set_file_extent_offset(leaf, extent,
2426 datao);
2427 btrfs_set_file_extent_num_bytes(leaf, extent,
2428 datal);
2429 if (disko) {
2430 inode_add_bytes(inode, datal);
2431 ret = btrfs_inc_extent_ref(trans, root,
2432 disko, diskl, 0,
2433 root->root_key.objectid,
2434 btrfs_ino(inode),
2435 new_key.offset - datao);
2436 BUG_ON(ret);
2437 }
2438 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2439 u64 skip = 0;
2440 u64 trim = 0;
2441 if (off > key.offset) {
2442 skip = off - key.offset;
2443 new_key.offset += skip;
2444 }
2445
2446 if (key.offset + datal > off+len)
2447 trim = key.offset + datal - (off+len);
2448
2449 if (comp && (skip || trim)) {
2450 ret = -EINVAL;
2451 btrfs_end_transaction(trans, root);
2452 goto out;
2453 }
2454 size -= skip + trim;
2455 datal -= skip + trim;
2456
2457 ret = btrfs_drop_extents(trans, inode,
2458 new_key.offset,
2459 new_key.offset + datal,
2460 &hint_byte, 1);
2461 BUG_ON(ret);
2462
2463 ret = btrfs_insert_empty_item(trans, root, path,
2464 &new_key, size);
2465 BUG_ON(ret);
2466
2467 if (skip) {
2468 u32 start =
2469 btrfs_file_extent_calc_inline_size(0);
2470 memmove(buf+start, buf+start+skip,
2471 datal);
2472 }
2473
2474 leaf = path->nodes[0];
2475 slot = path->slots[0];
2476 write_extent_buffer(leaf, buf,
2477 btrfs_item_ptr_offset(leaf, slot),
2478 size);
2479 inode_add_bytes(inode, datal);
2480 }
2481
2482 btrfs_mark_buffer_dirty(leaf);
2483 btrfs_release_path(path);
2484
2485 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2486
2487 /*
2488 * we round up to the block size at eof when
2489 * determining which extents to clone above,
2490 * but shouldn't round up the file size
2491 */
2492 endoff = new_key.offset + datal;
2493 if (endoff > destoff+olen)
2494 endoff = destoff+olen;
2495 if (endoff > inode->i_size)
2496 btrfs_i_size_write(inode, endoff);
2497
2498 ret = btrfs_update_inode(trans, root, inode);
2499 BUG_ON(ret);
2500 btrfs_end_transaction(trans, root);
2501 }
2502 next:
2503 btrfs_release_path(path);
2504 key.offset++;
2505 }
2506 ret = 0;
2507 out:
2508 btrfs_release_path(path);
2509 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2510 out_unlock:
2511 mutex_unlock(&src->i_mutex);
2512 mutex_unlock(&inode->i_mutex);
2513 vfree(buf);
2514 btrfs_free_path(path);
2515 out_fput:
2516 fput(src_file);
2517 out_drop_write:
2518 mnt_drop_write(file->f_path.mnt);
2519 return ret;
2520 }
2521
2522 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2523 {
2524 struct btrfs_ioctl_clone_range_args args;
2525
2526 if (copy_from_user(&args, argp, sizeof(args)))
2527 return -EFAULT;
2528 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2529 args.src_length, args.dest_offset);
2530 }
2531
2532 /*
2533 * there are many ways the trans_start and trans_end ioctls can lead
2534 * to deadlocks. They should only be used by applications that
2535 * basically own the machine, and have a very in depth understanding
2536 * of all the possible deadlocks and enospc problems.
2537 */
2538 static long btrfs_ioctl_trans_start(struct file *file)
2539 {
2540 struct inode *inode = fdentry(file)->d_inode;
2541 struct btrfs_root *root = BTRFS_I(inode)->root;
2542 struct btrfs_trans_handle *trans;
2543 int ret;
2544
2545 ret = -EPERM;
2546 if (!capable(CAP_SYS_ADMIN))
2547 goto out;
2548
2549 ret = -EINPROGRESS;
2550 if (file->private_data)
2551 goto out;
2552
2553 ret = -EROFS;
2554 if (btrfs_root_readonly(root))
2555 goto out;
2556
2557 ret = mnt_want_write(file->f_path.mnt);
2558 if (ret)
2559 goto out;
2560
2561 atomic_inc(&root->fs_info->open_ioctl_trans);
2562
2563 ret = -ENOMEM;
2564 trans = btrfs_start_ioctl_transaction(root);
2565 if (IS_ERR(trans))
2566 goto out_drop;
2567
2568 file->private_data = trans;
2569 return 0;
2570
2571 out_drop:
2572 atomic_dec(&root->fs_info->open_ioctl_trans);
2573 mnt_drop_write(file->f_path.mnt);
2574 out:
2575 return ret;
2576 }
2577
2578 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2579 {
2580 struct inode *inode = fdentry(file)->d_inode;
2581 struct btrfs_root *root = BTRFS_I(inode)->root;
2582 struct btrfs_root *new_root;
2583 struct btrfs_dir_item *di;
2584 struct btrfs_trans_handle *trans;
2585 struct btrfs_path *path;
2586 struct btrfs_key location;
2587 struct btrfs_disk_key disk_key;
2588 struct btrfs_super_block *disk_super;
2589 u64 features;
2590 u64 objectid = 0;
2591 u64 dir_id;
2592
2593 if (!capable(CAP_SYS_ADMIN))
2594 return -EPERM;
2595
2596 if (copy_from_user(&objectid, argp, sizeof(objectid)))
2597 return -EFAULT;
2598
2599 if (!objectid)
2600 objectid = root->root_key.objectid;
2601
2602 location.objectid = objectid;
2603 location.type = BTRFS_ROOT_ITEM_KEY;
2604 location.offset = (u64)-1;
2605
2606 new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2607 if (IS_ERR(new_root))
2608 return PTR_ERR(new_root);
2609
2610 if (btrfs_root_refs(&new_root->root_item) == 0)
2611 return -ENOENT;
2612
2613 path = btrfs_alloc_path();
2614 if (!path)
2615 return -ENOMEM;
2616 path->leave_spinning = 1;
2617
2618 trans = btrfs_start_transaction(root, 1);
2619 if (IS_ERR(trans)) {
2620 btrfs_free_path(path);
2621 return PTR_ERR(trans);
2622 }
2623
2624 dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
2625 di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2626 dir_id, "default", 7, 1);
2627 if (IS_ERR_OR_NULL(di)) {
2628 btrfs_free_path(path);
2629 btrfs_end_transaction(trans, root);
2630 printk(KERN_ERR "Umm, you don't have the default dir item, "
2631 "this isn't going to work\n");
2632 return -ENOENT;
2633 }
2634
2635 btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2636 btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2637 btrfs_mark_buffer_dirty(path->nodes[0]);
2638 btrfs_free_path(path);
2639
2640 disk_super = root->fs_info->super_copy;
2641 features = btrfs_super_incompat_flags(disk_super);
2642 if (!(features & BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)) {
2643 features |= BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL;
2644 btrfs_set_super_incompat_flags(disk_super, features);
2645 }
2646 btrfs_end_transaction(trans, root);
2647
2648 return 0;
2649 }
2650
2651 static void get_block_group_info(struct list_head *groups_list,
2652 struct btrfs_ioctl_space_info *space)
2653 {
2654 struct btrfs_block_group_cache *block_group;
2655
2656 space->total_bytes = 0;
2657 space->used_bytes = 0;
2658 space->flags = 0;
2659 list_for_each_entry(block_group, groups_list, list) {
2660 space->flags = block_group->flags;
2661 space->total_bytes += block_group->key.offset;
2662 space->used_bytes +=
2663 btrfs_block_group_used(&block_group->item);
2664 }
2665 }
2666
2667 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
2668 {
2669 struct btrfs_ioctl_space_args space_args;
2670 struct btrfs_ioctl_space_info space;
2671 struct btrfs_ioctl_space_info *dest;
2672 struct btrfs_ioctl_space_info *dest_orig;
2673 struct btrfs_ioctl_space_info __user *user_dest;
2674 struct btrfs_space_info *info;
2675 u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2676 BTRFS_BLOCK_GROUP_SYSTEM,
2677 BTRFS_BLOCK_GROUP_METADATA,
2678 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2679 int num_types = 4;
2680 int alloc_size;
2681 int ret = 0;
2682 u64 slot_count = 0;
2683 int i, c;
2684
2685 if (copy_from_user(&space_args,
2686 (struct btrfs_ioctl_space_args __user *)arg,
2687 sizeof(space_args)))
2688 return -EFAULT;
2689
2690 for (i = 0; i < num_types; i++) {
2691 struct btrfs_space_info *tmp;
2692
2693 info = NULL;
2694 rcu_read_lock();
2695 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2696 list) {
2697 if (tmp->flags == types[i]) {
2698 info = tmp;
2699 break;
2700 }
2701 }
2702 rcu_read_unlock();
2703
2704 if (!info)
2705 continue;
2706
2707 down_read(&info->groups_sem);
2708 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2709 if (!list_empty(&info->block_groups[c]))
2710 slot_count++;
2711 }
2712 up_read(&info->groups_sem);
2713 }
2714
2715 /* space_slots == 0 means they are asking for a count */
2716 if (space_args.space_slots == 0) {
2717 space_args.total_spaces = slot_count;
2718 goto out;
2719 }
2720
2721 slot_count = min_t(u64, space_args.space_slots, slot_count);
2722
2723 alloc_size = sizeof(*dest) * slot_count;
2724
2725 /* we generally have at most 6 or so space infos, one for each raid
2726 * level. So, a whole page should be more than enough for everyone
2727 */
2728 if (alloc_size > PAGE_CACHE_SIZE)
2729 return -ENOMEM;
2730
2731 space_args.total_spaces = 0;
2732 dest = kmalloc(alloc_size, GFP_NOFS);
2733 if (!dest)
2734 return -ENOMEM;
2735 dest_orig = dest;
2736
2737 /* now we have a buffer to copy into */
2738 for (i = 0; i < num_types; i++) {
2739 struct btrfs_space_info *tmp;
2740
2741 if (!slot_count)
2742 break;
2743
2744 info = NULL;
2745 rcu_read_lock();
2746 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2747 list) {
2748 if (tmp->flags == types[i]) {
2749 info = tmp;
2750 break;
2751 }
2752 }
2753 rcu_read_unlock();
2754
2755 if (!info)
2756 continue;
2757 down_read(&info->groups_sem);
2758 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2759 if (!list_empty(&info->block_groups[c])) {
2760 get_block_group_info(&info->block_groups[c],
2761 &space);
2762 memcpy(dest, &space, sizeof(space));
2763 dest++;
2764 space_args.total_spaces++;
2765 slot_count--;
2766 }
2767 if (!slot_count)
2768 break;
2769 }
2770 up_read(&info->groups_sem);
2771 }
2772
2773 user_dest = (struct btrfs_ioctl_space_info *)
2774 (arg + sizeof(struct btrfs_ioctl_space_args));
2775
2776 if (copy_to_user(user_dest, dest_orig, alloc_size))
2777 ret = -EFAULT;
2778
2779 kfree(dest_orig);
2780 out:
2781 if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
2782 ret = -EFAULT;
2783
2784 return ret;
2785 }
2786
2787 /*
2788 * there are many ways the trans_start and trans_end ioctls can lead
2789 * to deadlocks. They should only be used by applications that
2790 * basically own the machine, and have a very in depth understanding
2791 * of all the possible deadlocks and enospc problems.
2792 */
2793 long btrfs_ioctl_trans_end(struct file *file)
2794 {
2795 struct inode *inode = fdentry(file)->d_inode;
2796 struct btrfs_root *root = BTRFS_I(inode)->root;
2797 struct btrfs_trans_handle *trans;
2798
2799 trans = file->private_data;
2800 if (!trans)
2801 return -EINVAL;
2802 file->private_data = NULL;
2803
2804 btrfs_end_transaction(trans, root);
2805
2806 atomic_dec(&root->fs_info->open_ioctl_trans);
2807
2808 mnt_drop_write(file->f_path.mnt);
2809 return 0;
2810 }
2811
2812 static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp)
2813 {
2814 struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2815 struct btrfs_trans_handle *trans;
2816 u64 transid;
2817 int ret;
2818
2819 trans = btrfs_start_transaction(root, 0);
2820 if (IS_ERR(trans))
2821 return PTR_ERR(trans);
2822 transid = trans->transid;
2823 ret = btrfs_commit_transaction_async(trans, root, 0);
2824 if (ret) {
2825 btrfs_end_transaction(trans, root);
2826 return ret;
2827 }
2828
2829 if (argp)
2830 if (copy_to_user(argp, &transid, sizeof(transid)))
2831 return -EFAULT;
2832 return 0;
2833 }
2834
2835 static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp)
2836 {
2837 struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2838 u64 transid;
2839
2840 if (argp) {
2841 if (copy_from_user(&transid, argp, sizeof(transid)))
2842 return -EFAULT;
2843 } else {
2844 transid = 0; /* current trans */
2845 }
2846 return btrfs_wait_for_commit(root, transid);
2847 }
2848
2849 static long btrfs_ioctl_scrub(struct btrfs_root *root, void __user *arg)
2850 {
2851 int ret;
2852 struct btrfs_ioctl_scrub_args *sa;
2853
2854 if (!capable(CAP_SYS_ADMIN))
2855 return -EPERM;
2856
2857 sa = memdup_user(arg, sizeof(*sa));
2858 if (IS_ERR(sa))
2859 return PTR_ERR(sa);
2860
2861 ret = btrfs_scrub_dev(root, sa->devid, sa->start, sa->end,
2862 &sa->progress, sa->flags & BTRFS_SCRUB_READONLY);
2863
2864 if (copy_to_user(arg, sa, sizeof(*sa)))
2865 ret = -EFAULT;
2866
2867 kfree(sa);
2868 return ret;
2869 }
2870
2871 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
2872 {
2873 if (!capable(CAP_SYS_ADMIN))
2874 return -EPERM;
2875
2876 return btrfs_scrub_cancel(root);
2877 }
2878
2879 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
2880 void __user *arg)
2881 {
2882 struct btrfs_ioctl_scrub_args *sa;
2883 int ret;
2884
2885 if (!capable(CAP_SYS_ADMIN))
2886 return -EPERM;
2887
2888 sa = memdup_user(arg, sizeof(*sa));
2889 if (IS_ERR(sa))
2890 return PTR_ERR(sa);
2891
2892 ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
2893
2894 if (copy_to_user(arg, sa, sizeof(*sa)))
2895 ret = -EFAULT;
2896
2897 kfree(sa);
2898 return ret;
2899 }
2900
2901 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
2902 {
2903 int ret = 0;
2904 int i;
2905 u64 rel_ptr;
2906 int size;
2907 struct btrfs_ioctl_ino_path_args *ipa = NULL;
2908 struct inode_fs_paths *ipath = NULL;
2909 struct btrfs_path *path;
2910
2911 if (!capable(CAP_SYS_ADMIN))
2912 return -EPERM;
2913
2914 path = btrfs_alloc_path();
2915 if (!path) {
2916 ret = -ENOMEM;
2917 goto out;
2918 }
2919
2920 ipa = memdup_user(arg, sizeof(*ipa));
2921 if (IS_ERR(ipa)) {
2922 ret = PTR_ERR(ipa);
2923 ipa = NULL;
2924 goto out;
2925 }
2926
2927 size = min_t(u32, ipa->size, 4096);
2928 ipath = init_ipath(size, root, path);
2929 if (IS_ERR(ipath)) {
2930 ret = PTR_ERR(ipath);
2931 ipath = NULL;
2932 goto out;
2933 }
2934
2935 ret = paths_from_inode(ipa->inum, ipath);
2936 if (ret < 0)
2937 goto out;
2938
2939 for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
2940 rel_ptr = ipath->fspath->val[i] -
2941 (u64)(unsigned long)ipath->fspath->val;
2942 ipath->fspath->val[i] = rel_ptr;
2943 }
2944
2945 ret = copy_to_user((void *)(unsigned long)ipa->fspath,
2946 (void *)(unsigned long)ipath->fspath, size);
2947 if (ret) {
2948 ret = -EFAULT;
2949 goto out;
2950 }
2951
2952 out:
2953 btrfs_free_path(path);
2954 free_ipath(ipath);
2955 kfree(ipa);
2956
2957 return ret;
2958 }
2959
2960 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
2961 {
2962 struct btrfs_data_container *inodes = ctx;
2963 const size_t c = 3 * sizeof(u64);
2964
2965 if (inodes->bytes_left >= c) {
2966 inodes->bytes_left -= c;
2967 inodes->val[inodes->elem_cnt] = inum;
2968 inodes->val[inodes->elem_cnt + 1] = offset;
2969 inodes->val[inodes->elem_cnt + 2] = root;
2970 inodes->elem_cnt += 3;
2971 } else {
2972 inodes->bytes_missing += c - inodes->bytes_left;
2973 inodes->bytes_left = 0;
2974 inodes->elem_missed += 3;
2975 }
2976
2977 return 0;
2978 }
2979
2980 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
2981 void __user *arg)
2982 {
2983 int ret = 0;
2984 int size;
2985 u64 extent_offset;
2986 struct btrfs_ioctl_logical_ino_args *loi;
2987 struct btrfs_data_container *inodes = NULL;
2988 struct btrfs_path *path = NULL;
2989 struct btrfs_key key;
2990
2991 if (!capable(CAP_SYS_ADMIN))
2992 return -EPERM;
2993
2994 loi = memdup_user(arg, sizeof(*loi));
2995 if (IS_ERR(loi)) {
2996 ret = PTR_ERR(loi);
2997 loi = NULL;
2998 goto out;
2999 }
3000
3001 path = btrfs_alloc_path();
3002 if (!path) {
3003 ret = -ENOMEM;
3004 goto out;
3005 }
3006
3007 size = min_t(u32, loi->size, 4096);
3008 inodes = init_data_container(size);
3009 if (IS_ERR(inodes)) {
3010 ret = PTR_ERR(inodes);
3011 inodes = NULL;
3012 goto out;
3013 }
3014
3015 ret = extent_from_logical(root->fs_info, loi->logical, path, &key);
3016
3017 if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK)
3018 ret = -ENOENT;
3019 if (ret < 0)
3020 goto out;
3021
3022 extent_offset = loi->logical - key.objectid;
3023 ret = iterate_extent_inodes(root->fs_info, path, key.objectid,
3024 extent_offset, build_ino_list, inodes);
3025
3026 if (ret < 0)
3027 goto out;
3028
3029 ret = copy_to_user((void *)(unsigned long)loi->inodes,
3030 (void *)(unsigned long)inodes, size);
3031 if (ret)
3032 ret = -EFAULT;
3033
3034 out:
3035 btrfs_free_path(path);
3036 kfree(inodes);
3037 kfree(loi);
3038
3039 return ret;
3040 }
3041
3042 long btrfs_ioctl(struct file *file, unsigned int
3043 cmd, unsigned long arg)
3044 {
3045 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3046 void __user *argp = (void __user *)arg;
3047
3048 switch (cmd) {
3049 case FS_IOC_GETFLAGS:
3050 return btrfs_ioctl_getflags(file, argp);
3051 case FS_IOC_SETFLAGS:
3052 return btrfs_ioctl_setflags(file, argp);
3053 case FS_IOC_GETVERSION:
3054 return btrfs_ioctl_getversion(file, argp);
3055 case FITRIM:
3056 return btrfs_ioctl_fitrim(file, argp);
3057 case BTRFS_IOC_SNAP_CREATE:
3058 return btrfs_ioctl_snap_create(file, argp, 0);
3059 case BTRFS_IOC_SNAP_CREATE_V2:
3060 return btrfs_ioctl_snap_create_v2(file, argp, 0);
3061 case BTRFS_IOC_SUBVOL_CREATE:
3062 return btrfs_ioctl_snap_create(file, argp, 1);
3063 case BTRFS_IOC_SNAP_DESTROY:
3064 return btrfs_ioctl_snap_destroy(file, argp);
3065 case BTRFS_IOC_SUBVOL_GETFLAGS:
3066 return btrfs_ioctl_subvol_getflags(file, argp);
3067 case BTRFS_IOC_SUBVOL_SETFLAGS:
3068 return btrfs_ioctl_subvol_setflags(file, argp);
3069 case BTRFS_IOC_DEFAULT_SUBVOL:
3070 return btrfs_ioctl_default_subvol(file, argp);
3071 case BTRFS_IOC_DEFRAG:
3072 return btrfs_ioctl_defrag(file, NULL);
3073 case BTRFS_IOC_DEFRAG_RANGE:
3074 return btrfs_ioctl_defrag(file, argp);
3075 case BTRFS_IOC_RESIZE:
3076 return btrfs_ioctl_resize(root, argp);
3077 case BTRFS_IOC_ADD_DEV:
3078 return btrfs_ioctl_add_dev(root, argp);
3079 case BTRFS_IOC_RM_DEV:
3080 return btrfs_ioctl_rm_dev(root, argp);
3081 case BTRFS_IOC_FS_INFO:
3082 return btrfs_ioctl_fs_info(root, argp);
3083 case BTRFS_IOC_DEV_INFO:
3084 return btrfs_ioctl_dev_info(root, argp);
3085 case BTRFS_IOC_BALANCE:
3086 return btrfs_balance(root->fs_info->dev_root);
3087 case BTRFS_IOC_CLONE:
3088 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
3089 case BTRFS_IOC_CLONE_RANGE:
3090 return btrfs_ioctl_clone_range(file, argp);
3091 case BTRFS_IOC_TRANS_START:
3092 return btrfs_ioctl_trans_start(file);
3093 case BTRFS_IOC_TRANS_END:
3094 return btrfs_ioctl_trans_end(file);
3095 case BTRFS_IOC_TREE_SEARCH:
3096 return btrfs_ioctl_tree_search(file, argp);
3097 case BTRFS_IOC_INO_LOOKUP:
3098 return btrfs_ioctl_ino_lookup(file, argp);
3099 case BTRFS_IOC_INO_PATHS:
3100 return btrfs_ioctl_ino_to_path(root, argp);
3101 case BTRFS_IOC_LOGICAL_INO:
3102 return btrfs_ioctl_logical_to_ino(root, argp);
3103 case BTRFS_IOC_SPACE_INFO:
3104 return btrfs_ioctl_space_info(root, argp);
3105 case BTRFS_IOC_SYNC:
3106 btrfs_sync_fs(file->f_dentry->d_sb, 1);
3107 return 0;
3108 case BTRFS_IOC_START_SYNC:
3109 return btrfs_ioctl_start_sync(file, argp);
3110 case BTRFS_IOC_WAIT_SYNC:
3111 return btrfs_ioctl_wait_sync(file, argp);
3112 case BTRFS_IOC_SCRUB:
3113 return btrfs_ioctl_scrub(root, argp);
3114 case BTRFS_IOC_SCRUB_CANCEL:
3115 return btrfs_ioctl_scrub_cancel(root, argp);
3116 case BTRFS_IOC_SCRUB_PROGRESS:
3117 return btrfs_ioctl_scrub_progress(root, argp);
3118 }
3119
3120 return -ENOTTY;
3121 }
Linux with added FPC-III support