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