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Merge branch 'next/devel-samsung-pd' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6-xlnx.git] / fs / btrfs / ioctl.c
blobd8b54715c2deb655508229a7f4120e1141c8daae
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(file);
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(file);
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_fs_info *fs_info = btrfs_sb(fdentry(file)->d_sb);
290 struct btrfs_device *device;
291 struct request_queue *q;
292 struct fstrim_range range;
293 u64 minlen = ULLONG_MAX;
294 u64 num_devices = 0;
295 u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
296 int ret;
297
298 if (!capable(CAP_SYS_ADMIN))
299 return -EPERM;
300
301 rcu_read_lock();
302 list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
303 dev_list) {
304 if (!device->bdev)
305 continue;
306 q = bdev_get_queue(device->bdev);
307 if (blk_queue_discard(q)) {
308 num_devices++;
309 minlen = min((u64)q->limits.discard_granularity,
310 minlen);
311 }
312 }
313 rcu_read_unlock();
314
315 if (!num_devices)
316 return -EOPNOTSUPP;
317 if (copy_from_user(&range, arg, sizeof(range)))
318 return -EFAULT;
319 if (range.start > total_bytes)
320 return -EINVAL;
321
322 range.len = min(range.len, total_bytes - range.start);
323 range.minlen = max(range.minlen, minlen);
324 ret = btrfs_trim_fs(fs_info->tree_root, &range);
325 if (ret < 0)
326 return ret;
327
328 if (copy_to_user(arg, &range, sizeof(range)))
329 return -EFAULT;
330
331 return 0;
332 }
333
334 static noinline int create_subvol(struct btrfs_root *root,
335 struct dentry *dentry,
336 char *name, int namelen,
337 u64 *async_transid)
338 {
339 struct btrfs_trans_handle *trans;
340 struct btrfs_key key;
341 struct btrfs_root_item root_item;
342 struct btrfs_inode_item *inode_item;
343 struct extent_buffer *leaf;
344 struct btrfs_root *new_root;
345 struct dentry *parent = dentry->d_parent;
346 struct inode *dir;
347 int ret;
348 int err;
349 u64 objectid;
350 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
351 u64 index = 0;
352
353 ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
354 if (ret)
355 return ret;
356
357 dir = parent->d_inode;
358
359 /*
360 * 1 - inode item
361 * 2 - refs
362 * 1 - root item
363 * 2 - dir items
364 */
365 trans = btrfs_start_transaction(root, 6);
366 if (IS_ERR(trans))
367 return PTR_ERR(trans);
368
369 leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
370 0, objectid, NULL, 0, 0, 0, 0);
371 if (IS_ERR(leaf)) {
372 ret = PTR_ERR(leaf);
373 goto fail;
374 }
375
376 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
377 btrfs_set_header_bytenr(leaf, leaf->start);
378 btrfs_set_header_generation(leaf, trans->transid);
379 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
380 btrfs_set_header_owner(leaf, objectid);
381
382 write_extent_buffer(leaf, root->fs_info->fsid,
383 (unsigned long)btrfs_header_fsid(leaf),
384 BTRFS_FSID_SIZE);
385 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
386 (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
387 BTRFS_UUID_SIZE);
388 btrfs_mark_buffer_dirty(leaf);
389
390 inode_item = &root_item.inode;
391 memset(inode_item, 0, sizeof(*inode_item));
392 inode_item->generation = cpu_to_le64(1);
393 inode_item->size = cpu_to_le64(3);
394 inode_item->nlink = cpu_to_le32(1);
395 inode_item->nbytes = cpu_to_le64(root->leafsize);
396 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
397
398 root_item.flags = 0;
399 root_item.byte_limit = 0;
400 inode_item->flags = cpu_to_le64(BTRFS_INODE_ROOT_ITEM_INIT);
401
402 btrfs_set_root_bytenr(&root_item, leaf->start);
403 btrfs_set_root_generation(&root_item, trans->transid);
404 btrfs_set_root_level(&root_item, 0);
405 btrfs_set_root_refs(&root_item, 1);
406 btrfs_set_root_used(&root_item, leaf->len);
407 btrfs_set_root_last_snapshot(&root_item, 0);
408
409 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
410 root_item.drop_level = 0;
411
412 btrfs_tree_unlock(leaf);
413 free_extent_buffer(leaf);
414 leaf = NULL;
415
416 btrfs_set_root_dirid(&root_item, new_dirid);
417
418 key.objectid = objectid;
419 key.offset = 0;
420 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
421 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
422 &root_item);
423 if (ret)
424 goto fail;
425
426 key.offset = (u64)-1;
427 new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
428 BUG_ON(IS_ERR(new_root));
429
430 btrfs_record_root_in_trans(trans, new_root);
431
432 ret = btrfs_create_subvol_root(trans, new_root, new_dirid);
433 /*
434 * insert the directory item
435 */
436 ret = btrfs_set_inode_index(dir, &index);
437 BUG_ON(ret);
438
439 ret = btrfs_insert_dir_item(trans, root,
440 name, namelen, dir, &key,
441 BTRFS_FT_DIR, index);
442 if (ret)
443 goto fail;
444
445 btrfs_i_size_write(dir, dir->i_size + namelen * 2);
446 ret = btrfs_update_inode(trans, root, dir);
447 BUG_ON(ret);
448
449 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
450 objectid, root->root_key.objectid,
451 btrfs_ino(dir), index, name, namelen);
452
453 BUG_ON(ret);
454
455 d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
456 fail:
457 if (async_transid) {
458 *async_transid = trans->transid;
459 err = btrfs_commit_transaction_async(trans, root, 1);
460 } else {
461 err = btrfs_commit_transaction(trans, root);
462 }
463 if (err && !ret)
464 ret = err;
465 return ret;
466 }
467
468 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
469 char *name, int namelen, u64 *async_transid,
470 bool readonly)
471 {
472 struct inode *inode;
473 struct btrfs_pending_snapshot *pending_snapshot;
474 struct btrfs_trans_handle *trans;
475 int ret;
476
477 if (!root->ref_cows)
478 return -EINVAL;
479
480 pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
481 if (!pending_snapshot)
482 return -ENOMEM;
483
484 btrfs_init_block_rsv(&pending_snapshot->block_rsv);
485 pending_snapshot->dentry = dentry;
486 pending_snapshot->root = root;
487 pending_snapshot->readonly = readonly;
488
489 trans = btrfs_start_transaction(root->fs_info->extent_root, 5);
490 if (IS_ERR(trans)) {
491 ret = PTR_ERR(trans);
492 goto fail;
493 }
494
495 ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
496 BUG_ON(ret);
497
498 spin_lock(&root->fs_info->trans_lock);
499 list_add(&pending_snapshot->list,
500 &trans->transaction->pending_snapshots);
501 spin_unlock(&root->fs_info->trans_lock);
502 if (async_transid) {
503 *async_transid = trans->transid;
504 ret = btrfs_commit_transaction_async(trans,
505 root->fs_info->extent_root, 1);
506 } else {
507 ret = btrfs_commit_transaction(trans,
508 root->fs_info->extent_root);
509 }
510 BUG_ON(ret);
511
512 ret = pending_snapshot->error;
513 if (ret)
514 goto fail;
515
516 ret = btrfs_orphan_cleanup(pending_snapshot->snap);
517 if (ret)
518 goto fail;
519
520 inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
521 if (IS_ERR(inode)) {
522 ret = PTR_ERR(inode);
523 goto fail;
524 }
525 BUG_ON(!inode);
526 d_instantiate(dentry, inode);
527 ret = 0;
528 fail:
529 kfree(pending_snapshot);
530 return ret;
531 }
532
533 /* copy of check_sticky in fs/namei.c()
534 * It's inline, so penalty for filesystems that don't use sticky bit is
535 * minimal.
536 */
537 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode)
538 {
539 uid_t fsuid = current_fsuid();
540
541 if (!(dir->i_mode & S_ISVTX))
542 return 0;
543 if (inode->i_uid == fsuid)
544 return 0;
545 if (dir->i_uid == fsuid)
546 return 0;
547 return !capable(CAP_FOWNER);
548 }
549
550 /* copy of may_delete in fs/namei.c()
551 * Check whether we can remove a link victim from directory dir, check
552 * whether the type of victim is right.
553 * 1. We can't do it if dir is read-only (done in permission())
554 * 2. We should have write and exec permissions on dir
555 * 3. We can't remove anything from append-only dir
556 * 4. We can't do anything with immutable dir (done in permission())
557 * 5. If the sticky bit on dir is set we should either
558 * a. be owner of dir, or
559 * b. be owner of victim, or
560 * c. have CAP_FOWNER capability
561 * 6. If the victim is append-only or immutable we can't do antyhing with
562 * links pointing to it.
563 * 7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
564 * 8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
565 * 9. We can't remove a root or mountpoint.
566 * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
567 * nfs_async_unlink().
568 */
569
570 static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir)
571 {
572 int error;
573
574 if (!victim->d_inode)
575 return -ENOENT;
576
577 BUG_ON(victim->d_parent->d_inode != dir);
578 audit_inode_child(victim, dir);
579
580 error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
581 if (error)
582 return error;
583 if (IS_APPEND(dir))
584 return -EPERM;
585 if (btrfs_check_sticky(dir, victim->d_inode)||
586 IS_APPEND(victim->d_inode)||
587 IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
588 return -EPERM;
589 if (isdir) {
590 if (!S_ISDIR(victim->d_inode->i_mode))
591 return -ENOTDIR;
592 if (IS_ROOT(victim))
593 return -EBUSY;
594 } else if (S_ISDIR(victim->d_inode->i_mode))
595 return -EISDIR;
596 if (IS_DEADDIR(dir))
597 return -ENOENT;
598 if (victim->d_flags & DCACHE_NFSFS_RENAMED)
599 return -EBUSY;
600 return 0;
601 }
602
603 /* copy of may_create in fs/namei.c() */
604 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
605 {
606 if (child->d_inode)
607 return -EEXIST;
608 if (IS_DEADDIR(dir))
609 return -ENOENT;
610 return inode_permission(dir, MAY_WRITE | MAY_EXEC);
611 }
612
613 /*
614 * Create a new subvolume below @parent. This is largely modeled after
615 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
616 * inside this filesystem so it's quite a bit simpler.
617 */
618 static noinline int btrfs_mksubvol(struct path *parent,
619 char *name, int namelen,
620 struct btrfs_root *snap_src,
621 u64 *async_transid, bool readonly)
622 {
623 struct inode *dir = parent->dentry->d_inode;
624 struct dentry *dentry;
625 int error;
626
627 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
628
629 dentry = lookup_one_len(name, parent->dentry, namelen);
630 error = PTR_ERR(dentry);
631 if (IS_ERR(dentry))
632 goto out_unlock;
633
634 error = -EEXIST;
635 if (dentry->d_inode)
636 goto out_dput;
637
638 error = mnt_want_write(parent->mnt);
639 if (error)
640 goto out_dput;
641
642 error = btrfs_may_create(dir, dentry);
643 if (error)
644 goto out_drop_write;
645
646 down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
647
648 if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
649 goto out_up_read;
650
651 if (snap_src) {
652 error = create_snapshot(snap_src, dentry,
653 name, namelen, async_transid, readonly);
654 } else {
655 error = create_subvol(BTRFS_I(dir)->root, dentry,
656 name, namelen, async_transid);
657 }
658 if (!error)
659 fsnotify_mkdir(dir, dentry);
660 out_up_read:
661 up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
662 out_drop_write:
663 mnt_drop_write(parent->mnt);
664 out_dput:
665 dput(dentry);
666 out_unlock:
667 mutex_unlock(&dir->i_mutex);
668 return error;
669 }
670
671 /*
672 * When we're defragging a range, we don't want to kick it off again
673 * if it is really just waiting for delalloc to send it down.
674 * If we find a nice big extent or delalloc range for the bytes in the
675 * file you want to defrag, we return 0 to let you know to skip this
676 * part of the file
677 */
678 static int check_defrag_in_cache(struct inode *inode, u64 offset, int thresh)
679 {
680 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
681 struct extent_map *em = NULL;
682 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
683 u64 end;
684
685 read_lock(&em_tree->lock);
686 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
687 read_unlock(&em_tree->lock);
688
689 if (em) {
690 end = extent_map_end(em);
691 free_extent_map(em);
692 if (end - offset > thresh)
693 return 0;
694 }
695 /* if we already have a nice delalloc here, just stop */
696 thresh /= 2;
697 end = count_range_bits(io_tree, &offset, offset + thresh,
698 thresh, EXTENT_DELALLOC, 1);
699 if (end >= thresh)
700 return 0;
701 return 1;
702 }
703
704 /*
705 * helper function to walk through a file and find extents
706 * newer than a specific transid, and smaller than thresh.
707 *
708 * This is used by the defragging code to find new and small
709 * extents
710 */
711 static int find_new_extents(struct btrfs_root *root,
712 struct inode *inode, u64 newer_than,
713 u64 *off, int thresh)
714 {
715 struct btrfs_path *path;
716 struct btrfs_key min_key;
717 struct btrfs_key max_key;
718 struct extent_buffer *leaf;
719 struct btrfs_file_extent_item *extent;
720 int type;
721 int ret;
722 u64 ino = btrfs_ino(inode);
723
724 path = btrfs_alloc_path();
725 if (!path)
726 return -ENOMEM;
727
728 min_key.objectid = ino;
729 min_key.type = BTRFS_EXTENT_DATA_KEY;
730 min_key.offset = *off;
731
732 max_key.objectid = ino;
733 max_key.type = (u8)-1;
734 max_key.offset = (u64)-1;
735
736 path->keep_locks = 1;
737
738 while(1) {
739 ret = btrfs_search_forward(root, &min_key, &max_key,
740 path, 0, newer_than);
741 if (ret != 0)
742 goto none;
743 if (min_key.objectid != ino)
744 goto none;
745 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
746 goto none;
747
748 leaf = path->nodes[0];
749 extent = btrfs_item_ptr(leaf, path->slots[0],
750 struct btrfs_file_extent_item);
751
752 type = btrfs_file_extent_type(leaf, extent);
753 if (type == BTRFS_FILE_EXTENT_REG &&
754 btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
755 check_defrag_in_cache(inode, min_key.offset, thresh)) {
756 *off = min_key.offset;
757 btrfs_free_path(path);
758 return 0;
759 }
760
761 if (min_key.offset == (u64)-1)
762 goto none;
763
764 min_key.offset++;
765 btrfs_release_path(path);
766 }
767 none:
768 btrfs_free_path(path);
769 return -ENOENT;
770 }
771
772 static int should_defrag_range(struct inode *inode, u64 start, u64 len,
773 int thresh, u64 *last_len, u64 *skip,
774 u64 *defrag_end)
775 {
776 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
777 struct extent_map *em = NULL;
778 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
779 int ret = 1;
780
781 /*
782 * make sure that once we start defragging an extent, we keep on
783 * defragging it
784 */
785 if (start < *defrag_end)
786 return 1;
787
788 *skip = 0;
789
790 /*
791 * hopefully we have this extent in the tree already, try without
792 * the full extent lock
793 */
794 read_lock(&em_tree->lock);
795 em = lookup_extent_mapping(em_tree, start, len);
796 read_unlock(&em_tree->lock);
797
798 if (!em) {
799 /* get the big lock and read metadata off disk */
800 lock_extent(io_tree, start, start + len - 1, GFP_NOFS);
801 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
802 unlock_extent(io_tree, start, start + len - 1, GFP_NOFS);
803
804 if (IS_ERR(em))
805 return 0;
806 }
807
808 /* this will cover holes, and inline extents */
809 if (em->block_start >= EXTENT_MAP_LAST_BYTE)
810 ret = 0;
811
812 /*
813 * we hit a real extent, if it is big don't bother defragging it again
814 */
815 if ((*last_len == 0 || *last_len >= thresh) && em->len >= thresh)
816 ret = 0;
817
818 /*
819 * last_len ends up being a counter of how many bytes we've defragged.
820 * every time we choose not to defrag an extent, we reset *last_len
821 * so that the next tiny extent will force a defrag.
822 *
823 * The end result of this is that tiny extents before a single big
824 * extent will force at least part of that big extent to be defragged.
825 */
826 if (ret) {
827 *defrag_end = extent_map_end(em);
828 } else {
829 *last_len = 0;
830 *skip = extent_map_end(em);
831 *defrag_end = 0;
832 }
833
834 free_extent_map(em);
835 return ret;
836 }
837
838 /*
839 * it doesn't do much good to defrag one or two pages
840 * at a time. This pulls in a nice chunk of pages
841 * to COW and defrag.
842 *
843 * It also makes sure the delalloc code has enough
844 * dirty data to avoid making new small extents as part
845 * of the defrag
846 *
847 * It's a good idea to start RA on this range
848 * before calling this.
849 */
850 static int cluster_pages_for_defrag(struct inode *inode,
851 struct page **pages,
852 unsigned long start_index,
853 int num_pages)
854 {
855 unsigned long file_end;
856 u64 isize = i_size_read(inode);
857 u64 page_start;
858 u64 page_end;
859 int ret;
860 int i;
861 int i_done;
862 struct btrfs_ordered_extent *ordered;
863 struct extent_state *cached_state = NULL;
864 struct extent_io_tree *tree;
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 ret = btrfs_delalloc_reserve_space(inode,
872 num_pages << PAGE_CACHE_SHIFT);
873 if (ret)
874 return ret;
875 i_done = 0;
876 tree = &BTRFS_I(inode)->io_tree;
877
878 /* step one, lock all the pages */
879 for (i = 0; i < num_pages; i++) {
880 struct page *page;
881 again:
882 page = find_or_create_page(inode->i_mapping,
883 start_index + i, mask);
884 if (!page)
885 break;
886
887 page_start = page_offset(page);
888 page_end = page_start + PAGE_CACHE_SIZE - 1;
889 while (1) {
890 lock_extent(tree, page_start, page_end, GFP_NOFS);
891 ordered = btrfs_lookup_ordered_extent(inode,
892 page_start);
893 unlock_extent(tree, page_start, page_end, GFP_NOFS);
894 if (!ordered)
895 break;
896
897 unlock_page(page);
898 btrfs_start_ordered_extent(inode, ordered, 1);
899 btrfs_put_ordered_extent(ordered);
900 lock_page(page);
901 }
902
903 if (!PageUptodate(page)) {
904 btrfs_readpage(NULL, page);
905 lock_page(page);
906 if (!PageUptodate(page)) {
907 unlock_page(page);
908 page_cache_release(page);
909 ret = -EIO;
910 break;
911 }
912 }
913
914 isize = i_size_read(inode);
915 file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
916 if (!isize || page->index > file_end) {
917 /* whoops, we blew past eof, skip this page */
918 unlock_page(page);
919 page_cache_release(page);
920 break;
921 }
922
923 if (page->mapping != inode->i_mapping) {
924 unlock_page(page);
925 page_cache_release(page);
926 goto again;
927 }
928
929 pages[i] = page;
930 i_done++;
931 }
932 if (!i_done || ret)
933 goto out;
934
935 if (!(inode->i_sb->s_flags & MS_ACTIVE))
936 goto out;
937
938 /*
939 * so now we have a nice long stream of locked
940 * and up to date pages, lets wait on them
941 */
942 for (i = 0; i < i_done; i++)
943 wait_on_page_writeback(pages[i]);
944
945 page_start = page_offset(pages[0]);
946 page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
947
948 lock_extent_bits(&BTRFS_I(inode)->io_tree,
949 page_start, page_end - 1, 0, &cached_state,
950 GFP_NOFS);
951 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
952 page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
953 EXTENT_DO_ACCOUNTING, 0, 0, &cached_state,
954 GFP_NOFS);
955
956 if (i_done != num_pages) {
957 spin_lock(&BTRFS_I(inode)->lock);
958 BTRFS_I(inode)->outstanding_extents++;
959 spin_unlock(&BTRFS_I(inode)->lock);
960 btrfs_delalloc_release_space(inode,
961 (num_pages - i_done) << PAGE_CACHE_SHIFT);
962 }
963
964
965 btrfs_set_extent_delalloc(inode, page_start, page_end - 1,
966 &cached_state);
967
968 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
969 page_start, page_end - 1, &cached_state,
970 GFP_NOFS);
971
972 for (i = 0; i < i_done; i++) {
973 clear_page_dirty_for_io(pages[i]);
974 ClearPageChecked(pages[i]);
975 set_page_extent_mapped(pages[i]);
976 set_page_dirty(pages[i]);
977 unlock_page(pages[i]);
978 page_cache_release(pages[i]);
979 }
980 return i_done;
981 out:
982 for (i = 0; i < i_done; i++) {
983 unlock_page(pages[i]);
984 page_cache_release(pages[i]);
985 }
986 btrfs_delalloc_release_space(inode, num_pages << PAGE_CACHE_SHIFT);
987 return ret;
988
989 }
990
991 int btrfs_defrag_file(struct inode *inode, struct file *file,
992 struct btrfs_ioctl_defrag_range_args *range,
993 u64 newer_than, unsigned long max_to_defrag)
994 {
995 struct btrfs_root *root = BTRFS_I(inode)->root;
996 struct btrfs_super_block *disk_super;
997 struct file_ra_state *ra = NULL;
998 unsigned long last_index;
999 u64 isize = i_size_read(inode);
1000 u64 features;
1001 u64 last_len = 0;
1002 u64 skip = 0;
1003 u64 defrag_end = 0;
1004 u64 newer_off = range->start;
1005 unsigned long i;
1006 unsigned long ra_index = 0;
1007 int ret;
1008 int defrag_count = 0;
1009 int compress_type = BTRFS_COMPRESS_ZLIB;
1010 int extent_thresh = range->extent_thresh;
1011 int max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT;
1012 int cluster = max_cluster;
1013 u64 new_align = ~((u64)128 * 1024 - 1);
1014 struct page **pages = NULL;
1015
1016 if (extent_thresh == 0)
1017 extent_thresh = 256 * 1024;
1018
1019 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1020 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1021 return -EINVAL;
1022 if (range->compress_type)
1023 compress_type = range->compress_type;
1024 }
1025
1026 if (isize == 0)
1027 return 0;
1028
1029 /*
1030 * if we were not given a file, allocate a readahead
1031 * context
1032 */
1033 if (!file) {
1034 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1035 if (!ra)
1036 return -ENOMEM;
1037 file_ra_state_init(ra, inode->i_mapping);
1038 } else {
1039 ra = &file->f_ra;
1040 }
1041
1042 pages = kmalloc(sizeof(struct page *) * max_cluster,
1043 GFP_NOFS);
1044 if (!pages) {
1045 ret = -ENOMEM;
1046 goto out_ra;
1047 }
1048
1049 /* find the last page to defrag */
1050 if (range->start + range->len > range->start) {
1051 last_index = min_t(u64, isize - 1,
1052 range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
1053 } else {
1054 last_index = (isize - 1) >> PAGE_CACHE_SHIFT;
1055 }
1056
1057 if (newer_than) {
1058 ret = find_new_extents(root, inode, newer_than,
1059 &newer_off, 64 * 1024);
1060 if (!ret) {
1061 range->start = newer_off;
1062 /*
1063 * we always align our defrag to help keep
1064 * the extents in the file evenly spaced
1065 */
1066 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1067 } else
1068 goto out_ra;
1069 } else {
1070 i = range->start >> PAGE_CACHE_SHIFT;
1071 }
1072 if (!max_to_defrag)
1073 max_to_defrag = last_index + 1;
1074
1075 /*
1076 * make writeback starts from i, so the defrag range can be
1077 * written sequentially.
1078 */
1079 if (i < inode->i_mapping->writeback_index)
1080 inode->i_mapping->writeback_index = i;
1081
1082 while (i <= last_index && defrag_count < max_to_defrag &&
1083 (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1084 PAGE_CACHE_SHIFT)) {
1085 /*
1086 * make sure we stop running if someone unmounts
1087 * the FS
1088 */
1089 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1090 break;
1091
1092 if (!newer_than &&
1093 !should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
1094 PAGE_CACHE_SIZE,
1095 extent_thresh,
1096 &last_len, &skip,
1097 &defrag_end)) {
1098 unsigned long next;
1099 /*
1100 * the should_defrag function tells us how much to skip
1101 * bump our counter by the suggested amount
1102 */
1103 next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1104 i = max(i + 1, next);
1105 continue;
1106 }
1107
1108 if (!newer_than) {
1109 cluster = (PAGE_CACHE_ALIGN(defrag_end) >>
1110 PAGE_CACHE_SHIFT) - i;
1111 cluster = min(cluster, max_cluster);
1112 } else {
1113 cluster = max_cluster;
1114 }
1115
1116 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1117 BTRFS_I(inode)->force_compress = compress_type;
1118
1119 if (i + cluster > ra_index) {
1120 ra_index = max(i, ra_index);
1121 btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1122 cluster);
1123 ra_index += max_cluster;
1124 }
1125
1126 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1127 if (ret < 0)
1128 goto out_ra;
1129
1130 defrag_count += ret;
1131 balance_dirty_pages_ratelimited_nr(inode->i_mapping, ret);
1132
1133 if (newer_than) {
1134 if (newer_off == (u64)-1)
1135 break;
1136
1137 newer_off = max(newer_off + 1,
1138 (u64)i << PAGE_CACHE_SHIFT);
1139
1140 ret = find_new_extents(root, inode,
1141 newer_than, &newer_off,
1142 64 * 1024);
1143 if (!ret) {
1144 range->start = newer_off;
1145 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1146 } else {
1147 break;
1148 }
1149 } else {
1150 if (ret > 0) {
1151 i += ret;
1152 last_len += ret << PAGE_CACHE_SHIFT;
1153 } else {
1154 i++;
1155 last_len = 0;
1156 }
1157 }
1158 }
1159
1160 if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
1161 filemap_flush(inode->i_mapping);
1162
1163 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1164 /* the filemap_flush will queue IO into the worker threads, but
1165 * we have to make sure the IO is actually started and that
1166 * ordered extents get created before we return
1167 */
1168 atomic_inc(&root->fs_info->async_submit_draining);
1169 while (atomic_read(&root->fs_info->nr_async_submits) ||
1170 atomic_read(&root->fs_info->async_delalloc_pages)) {
1171 wait_event(root->fs_info->async_submit_wait,
1172 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1173 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1174 }
1175 atomic_dec(&root->fs_info->async_submit_draining);
1176
1177 mutex_lock(&inode->i_mutex);
1178 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1179 mutex_unlock(&inode->i_mutex);
1180 }
1181
1182 disk_super = root->fs_info->super_copy;
1183 features = btrfs_super_incompat_flags(disk_super);
1184 if (range->compress_type == BTRFS_COMPRESS_LZO) {
1185 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
1186 btrfs_set_super_incompat_flags(disk_super, features);
1187 }
1188
1189 ret = defrag_count;
1190
1191 out_ra:
1192 if (!file)
1193 kfree(ra);
1194 kfree(pages);
1195 return ret;
1196 }
1197
1198 static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
1199 void __user *arg)
1200 {
1201 u64 new_size;
1202 u64 old_size;
1203 u64 devid = 1;
1204 struct btrfs_ioctl_vol_args *vol_args;
1205 struct btrfs_trans_handle *trans;
1206 struct btrfs_device *device = NULL;
1207 char *sizestr;
1208 char *devstr = NULL;
1209 int ret = 0;
1210 int mod = 0;
1211
1212 if (root->fs_info->sb->s_flags & MS_RDONLY)
1213 return -EROFS;
1214
1215 if (!capable(CAP_SYS_ADMIN))
1216 return -EPERM;
1217
1218 mutex_lock(&root->fs_info->volume_mutex);
1219 if (root->fs_info->balance_ctl) {
1220 printk(KERN_INFO "btrfs: balance in progress\n");
1221 ret = -EINVAL;
1222 goto out;
1223 }
1224
1225 vol_args = memdup_user(arg, sizeof(*vol_args));
1226 if (IS_ERR(vol_args)) {
1227 ret = PTR_ERR(vol_args);
1228 goto out;
1229 }
1230
1231 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1232
1233 sizestr = vol_args->name;
1234 devstr = strchr(sizestr, ':');
1235 if (devstr) {
1236 char *end;
1237 sizestr = devstr + 1;
1238 *devstr = '\0';
1239 devstr = vol_args->name;
1240 devid = simple_strtoull(devstr, &end, 10);
1241 printk(KERN_INFO "btrfs: resizing devid %llu\n",
1242 (unsigned long long)devid);
1243 }
1244 device = btrfs_find_device(root, devid, NULL, NULL);
1245 if (!device) {
1246 printk(KERN_INFO "btrfs: resizer unable to find device %llu\n",
1247 (unsigned long long)devid);
1248 ret = -EINVAL;
1249 goto out_free;
1250 }
1251 if (!strcmp(sizestr, "max"))
1252 new_size = device->bdev->bd_inode->i_size;
1253 else {
1254 if (sizestr[0] == '-') {
1255 mod = -1;
1256 sizestr++;
1257 } else if (sizestr[0] == '+') {
1258 mod = 1;
1259 sizestr++;
1260 }
1261 new_size = memparse(sizestr, NULL);
1262 if (new_size == 0) {
1263 ret = -EINVAL;
1264 goto out_free;
1265 }
1266 }
1267
1268 old_size = device->total_bytes;
1269
1270 if (mod < 0) {
1271 if (new_size > old_size) {
1272 ret = -EINVAL;
1273 goto out_free;
1274 }
1275 new_size = old_size - new_size;
1276 } else if (mod > 0) {
1277 new_size = old_size + new_size;
1278 }
1279
1280 if (new_size < 256 * 1024 * 1024) {
1281 ret = -EINVAL;
1282 goto out_free;
1283 }
1284 if (new_size > device->bdev->bd_inode->i_size) {
1285 ret = -EFBIG;
1286 goto out_free;
1287 }
1288
1289 do_div(new_size, root->sectorsize);
1290 new_size *= root->sectorsize;
1291
1292 printk(KERN_INFO "btrfs: new size for %s is %llu\n",
1293 device->name, (unsigned long long)new_size);
1294
1295 if (new_size > old_size) {
1296 trans = btrfs_start_transaction(root, 0);
1297 if (IS_ERR(trans)) {
1298 ret = PTR_ERR(trans);
1299 goto out_free;
1300 }
1301 ret = btrfs_grow_device(trans, device, new_size);
1302 btrfs_commit_transaction(trans, root);
1303 } else if (new_size < old_size) {
1304 ret = btrfs_shrink_device(device, new_size);
1305 }
1306
1307 out_free:
1308 kfree(vol_args);
1309 out:
1310 mutex_unlock(&root->fs_info->volume_mutex);
1311 return ret;
1312 }
1313
1314 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1315 char *name,
1316 unsigned long fd,
1317 int subvol,
1318 u64 *transid,
1319 bool readonly)
1320 {
1321 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
1322 struct file *src_file;
1323 int namelen;
1324 int ret = 0;
1325
1326 if (root->fs_info->sb->s_flags & MS_RDONLY)
1327 return -EROFS;
1328
1329 namelen = strlen(name);
1330 if (strchr(name, '/')) {
1331 ret = -EINVAL;
1332 goto out;
1333 }
1334
1335 if (name[0] == '.' &&
1336 (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1337 ret = -EEXIST;
1338 goto out;
1339 }
1340
1341 if (subvol) {
1342 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1343 NULL, transid, readonly);
1344 } else {
1345 struct inode *src_inode;
1346 src_file = fget(fd);
1347 if (!src_file) {
1348 ret = -EINVAL;
1349 goto out;
1350 }
1351
1352 src_inode = src_file->f_path.dentry->d_inode;
1353 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
1354 printk(KERN_INFO "btrfs: Snapshot src from "
1355 "another FS\n");
1356 ret = -EINVAL;
1357 fput(src_file);
1358 goto out;
1359 }
1360 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1361 BTRFS_I(src_inode)->root,
1362 transid, readonly);
1363 fput(src_file);
1364 }
1365 out:
1366 return ret;
1367 }
1368
1369 static noinline int btrfs_ioctl_snap_create(struct file *file,
1370 void __user *arg, int subvol)
1371 {
1372 struct btrfs_ioctl_vol_args *vol_args;
1373 int ret;
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_PATH_NAME_MAX] = '\0';
1379
1380 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1381 vol_args->fd, subvol,
1382 NULL, false);
1383
1384 kfree(vol_args);
1385 return ret;
1386 }
1387
1388 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1389 void __user *arg, int subvol)
1390 {
1391 struct btrfs_ioctl_vol_args_v2 *vol_args;
1392 int ret;
1393 u64 transid = 0;
1394 u64 *ptr = NULL;
1395 bool readonly = false;
1396
1397 vol_args = memdup_user(arg, sizeof(*vol_args));
1398 if (IS_ERR(vol_args))
1399 return PTR_ERR(vol_args);
1400 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1401
1402 if (vol_args->flags &
1403 ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY)) {
1404 ret = -EOPNOTSUPP;
1405 goto out;
1406 }
1407
1408 if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1409 ptr = &transid;
1410 if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1411 readonly = true;
1412
1413 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1414 vol_args->fd, subvol,
1415 ptr, readonly);
1416
1417 if (ret == 0 && ptr &&
1418 copy_to_user(arg +
1419 offsetof(struct btrfs_ioctl_vol_args_v2,
1420 transid), ptr, sizeof(*ptr)))
1421 ret = -EFAULT;
1422 out:
1423 kfree(vol_args);
1424 return ret;
1425 }
1426
1427 static noinline int btrfs_ioctl_subvol_getflags(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 int ret = 0;
1433 u64 flags = 0;
1434
1435 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1436 return -EINVAL;
1437
1438 down_read(&root->fs_info->subvol_sem);
1439 if (btrfs_root_readonly(root))
1440 flags |= BTRFS_SUBVOL_RDONLY;
1441 up_read(&root->fs_info->subvol_sem);
1442
1443 if (copy_to_user(arg, &flags, sizeof(flags)))
1444 ret = -EFAULT;
1445
1446 return ret;
1447 }
1448
1449 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1450 void __user *arg)
1451 {
1452 struct inode *inode = fdentry(file)->d_inode;
1453 struct btrfs_root *root = BTRFS_I(inode)->root;
1454 struct btrfs_trans_handle *trans;
1455 u64 root_flags;
1456 u64 flags;
1457 int ret = 0;
1458
1459 if (root->fs_info->sb->s_flags & MS_RDONLY)
1460 return -EROFS;
1461
1462 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1463 return -EINVAL;
1464
1465 if (copy_from_user(&flags, arg, sizeof(flags)))
1466 return -EFAULT;
1467
1468 if (flags & BTRFS_SUBVOL_CREATE_ASYNC)
1469 return -EINVAL;
1470
1471 if (flags & ~BTRFS_SUBVOL_RDONLY)
1472 return -EOPNOTSUPP;
1473
1474 if (!inode_owner_or_capable(inode))
1475 return -EACCES;
1476
1477 down_write(&root->fs_info->subvol_sem);
1478
1479 /* nothing to do */
1480 if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1481 goto out;
1482
1483 root_flags = btrfs_root_flags(&root->root_item);
1484 if (flags & BTRFS_SUBVOL_RDONLY)
1485 btrfs_set_root_flags(&root->root_item,
1486 root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1487 else
1488 btrfs_set_root_flags(&root->root_item,
1489 root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1490
1491 trans = btrfs_start_transaction(root, 1);
1492 if (IS_ERR(trans)) {
1493 ret = PTR_ERR(trans);
1494 goto out_reset;
1495 }
1496
1497 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1498 &root->root_key, &root->root_item);
1499
1500 btrfs_commit_transaction(trans, root);
1501 out_reset:
1502 if (ret)
1503 btrfs_set_root_flags(&root->root_item, root_flags);
1504 out:
1505 up_write(&root->fs_info->subvol_sem);
1506 return ret;
1507 }
1508
1509 /*
1510 * helper to check if the subvolume references other subvolumes
1511 */
1512 static noinline int may_destroy_subvol(struct btrfs_root *root)
1513 {
1514 struct btrfs_path *path;
1515 struct btrfs_key key;
1516 int ret;
1517
1518 path = btrfs_alloc_path();
1519 if (!path)
1520 return -ENOMEM;
1521
1522 key.objectid = root->root_key.objectid;
1523 key.type = BTRFS_ROOT_REF_KEY;
1524 key.offset = (u64)-1;
1525
1526 ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1527 &key, path, 0, 0);
1528 if (ret < 0)
1529 goto out;
1530 BUG_ON(ret == 0);
1531
1532 ret = 0;
1533 if (path->slots[0] > 0) {
1534 path->slots[0]--;
1535 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1536 if (key.objectid == root->root_key.objectid &&
1537 key.type == BTRFS_ROOT_REF_KEY)
1538 ret = -ENOTEMPTY;
1539 }
1540 out:
1541 btrfs_free_path(path);
1542 return ret;
1543 }
1544
1545 static noinline int key_in_sk(struct btrfs_key *key,
1546 struct btrfs_ioctl_search_key *sk)
1547 {
1548 struct btrfs_key test;
1549 int ret;
1550
1551 test.objectid = sk->min_objectid;
1552 test.type = sk->min_type;
1553 test.offset = sk->min_offset;
1554
1555 ret = btrfs_comp_cpu_keys(key, &test);
1556 if (ret < 0)
1557 return 0;
1558
1559 test.objectid = sk->max_objectid;
1560 test.type = sk->max_type;
1561 test.offset = sk->max_offset;
1562
1563 ret = btrfs_comp_cpu_keys(key, &test);
1564 if (ret > 0)
1565 return 0;
1566 return 1;
1567 }
1568
1569 static noinline int copy_to_sk(struct btrfs_root *root,
1570 struct btrfs_path *path,
1571 struct btrfs_key *key,
1572 struct btrfs_ioctl_search_key *sk,
1573 char *buf,
1574 unsigned long *sk_offset,
1575 int *num_found)
1576 {
1577 u64 found_transid;
1578 struct extent_buffer *leaf;
1579 struct btrfs_ioctl_search_header sh;
1580 unsigned long item_off;
1581 unsigned long item_len;
1582 int nritems;
1583 int i;
1584 int slot;
1585 int ret = 0;
1586
1587 leaf = path->nodes[0];
1588 slot = path->slots[0];
1589 nritems = btrfs_header_nritems(leaf);
1590
1591 if (btrfs_header_generation(leaf) > sk->max_transid) {
1592 i = nritems;
1593 goto advance_key;
1594 }
1595 found_transid = btrfs_header_generation(leaf);
1596
1597 for (i = slot; i < nritems; i++) {
1598 item_off = btrfs_item_ptr_offset(leaf, i);
1599 item_len = btrfs_item_size_nr(leaf, i);
1600
1601 if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1602 item_len = 0;
1603
1604 if (sizeof(sh) + item_len + *sk_offset >
1605 BTRFS_SEARCH_ARGS_BUFSIZE) {
1606 ret = 1;
1607 goto overflow;
1608 }
1609
1610 btrfs_item_key_to_cpu(leaf, key, i);
1611 if (!key_in_sk(key, sk))
1612 continue;
1613
1614 sh.objectid = key->objectid;
1615 sh.offset = key->offset;
1616 sh.type = key->type;
1617 sh.len = item_len;
1618 sh.transid = found_transid;
1619
1620 /* copy search result header */
1621 memcpy(buf + *sk_offset, &sh, sizeof(sh));
1622 *sk_offset += sizeof(sh);
1623
1624 if (item_len) {
1625 char *p = buf + *sk_offset;
1626 /* copy the item */
1627 read_extent_buffer(leaf, p,
1628 item_off, item_len);
1629 *sk_offset += item_len;
1630 }
1631 (*num_found)++;
1632
1633 if (*num_found >= sk->nr_items)
1634 break;
1635 }
1636 advance_key:
1637 ret = 0;
1638 if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1639 key->offset++;
1640 else if (key->type < (u8)-1 && key->type < sk->max_type) {
1641 key->offset = 0;
1642 key->type++;
1643 } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1644 key->offset = 0;
1645 key->type = 0;
1646 key->objectid++;
1647 } else
1648 ret = 1;
1649 overflow:
1650 return ret;
1651 }
1652
1653 static noinline int search_ioctl(struct inode *inode,
1654 struct btrfs_ioctl_search_args *args)
1655 {
1656 struct btrfs_root *root;
1657 struct btrfs_key key;
1658 struct btrfs_key max_key;
1659 struct btrfs_path *path;
1660 struct btrfs_ioctl_search_key *sk = &args->key;
1661 struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1662 int ret;
1663 int num_found = 0;
1664 unsigned long sk_offset = 0;
1665
1666 path = btrfs_alloc_path();
1667 if (!path)
1668 return -ENOMEM;
1669
1670 if (sk->tree_id == 0) {
1671 /* search the root of the inode that was passed */
1672 root = BTRFS_I(inode)->root;
1673 } else {
1674 key.objectid = sk->tree_id;
1675 key.type = BTRFS_ROOT_ITEM_KEY;
1676 key.offset = (u64)-1;
1677 root = btrfs_read_fs_root_no_name(info, &key);
1678 if (IS_ERR(root)) {
1679 printk(KERN_ERR "could not find root %llu\n",
1680 sk->tree_id);
1681 btrfs_free_path(path);
1682 return -ENOENT;
1683 }
1684 }
1685
1686 key.objectid = sk->min_objectid;
1687 key.type = sk->min_type;
1688 key.offset = sk->min_offset;
1689
1690 max_key.objectid = sk->max_objectid;
1691 max_key.type = sk->max_type;
1692 max_key.offset = sk->max_offset;
1693
1694 path->keep_locks = 1;
1695
1696 while(1) {
1697 ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1698 sk->min_transid);
1699 if (ret != 0) {
1700 if (ret > 0)
1701 ret = 0;
1702 goto err;
1703 }
1704 ret = copy_to_sk(root, path, &key, sk, args->buf,
1705 &sk_offset, &num_found);
1706 btrfs_release_path(path);
1707 if (ret || num_found >= sk->nr_items)
1708 break;
1709
1710 }
1711 ret = 0;
1712 err:
1713 sk->nr_items = num_found;
1714 btrfs_free_path(path);
1715 return ret;
1716 }
1717
1718 static noinline int btrfs_ioctl_tree_search(struct file *file,
1719 void __user *argp)
1720 {
1721 struct btrfs_ioctl_search_args *args;
1722 struct inode *inode;
1723 int ret;
1724
1725 if (!capable(CAP_SYS_ADMIN))
1726 return -EPERM;
1727
1728 args = memdup_user(argp, sizeof(*args));
1729 if (IS_ERR(args))
1730 return PTR_ERR(args);
1731
1732 inode = fdentry(file)->d_inode;
1733 ret = search_ioctl(inode, args);
1734 if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1735 ret = -EFAULT;
1736 kfree(args);
1737 return ret;
1738 }
1739
1740 /*
1741 * Search INODE_REFs to identify path name of 'dirid' directory
1742 * in a 'tree_id' tree. and sets path name to 'name'.
1743 */
1744 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1745 u64 tree_id, u64 dirid, char *name)
1746 {
1747 struct btrfs_root *root;
1748 struct btrfs_key key;
1749 char *ptr;
1750 int ret = -1;
1751 int slot;
1752 int len;
1753 int total_len = 0;
1754 struct btrfs_inode_ref *iref;
1755 struct extent_buffer *l;
1756 struct btrfs_path *path;
1757
1758 if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1759 name[0]='\0';
1760 return 0;
1761 }
1762
1763 path = btrfs_alloc_path();
1764 if (!path)
1765 return -ENOMEM;
1766
1767 ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1768
1769 key.objectid = tree_id;
1770 key.type = BTRFS_ROOT_ITEM_KEY;
1771 key.offset = (u64)-1;
1772 root = btrfs_read_fs_root_no_name(info, &key);
1773 if (IS_ERR(root)) {
1774 printk(KERN_ERR "could not find root %llu\n", tree_id);
1775 ret = -ENOENT;
1776 goto out;
1777 }
1778
1779 key.objectid = dirid;
1780 key.type = BTRFS_INODE_REF_KEY;
1781 key.offset = (u64)-1;
1782
1783 while(1) {
1784 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1785 if (ret < 0)
1786 goto out;
1787
1788 l = path->nodes[0];
1789 slot = path->slots[0];
1790 if (ret > 0 && slot > 0)
1791 slot--;
1792 btrfs_item_key_to_cpu(l, &key, slot);
1793
1794 if (ret > 0 && (key.objectid != dirid ||
1795 key.type != BTRFS_INODE_REF_KEY)) {
1796 ret = -ENOENT;
1797 goto out;
1798 }
1799
1800 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1801 len = btrfs_inode_ref_name_len(l, iref);
1802 ptr -= len + 1;
1803 total_len += len + 1;
1804 if (ptr < name)
1805 goto out;
1806
1807 *(ptr + len) = '/';
1808 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1809
1810 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1811 break;
1812
1813 btrfs_release_path(path);
1814 key.objectid = key.offset;
1815 key.offset = (u64)-1;
1816 dirid = key.objectid;
1817 }
1818 if (ptr < name)
1819 goto out;
1820 memmove(name, ptr, total_len);
1821 name[total_len]='\0';
1822 ret = 0;
1823 out:
1824 btrfs_free_path(path);
1825 return ret;
1826 }
1827
1828 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1829 void __user *argp)
1830 {
1831 struct btrfs_ioctl_ino_lookup_args *args;
1832 struct inode *inode;
1833 int ret;
1834
1835 if (!capable(CAP_SYS_ADMIN))
1836 return -EPERM;
1837
1838 args = memdup_user(argp, sizeof(*args));
1839 if (IS_ERR(args))
1840 return PTR_ERR(args);
1841
1842 inode = fdentry(file)->d_inode;
1843
1844 if (args->treeid == 0)
1845 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
1846
1847 ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
1848 args->treeid, args->objectid,
1849 args->name);
1850
1851 if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1852 ret = -EFAULT;
1853
1854 kfree(args);
1855 return ret;
1856 }
1857
1858 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
1859 void __user *arg)
1860 {
1861 struct dentry *parent = fdentry(file);
1862 struct dentry *dentry;
1863 struct inode *dir = parent->d_inode;
1864 struct inode *inode;
1865 struct btrfs_root *root = BTRFS_I(dir)->root;
1866 struct btrfs_root *dest = NULL;
1867 struct btrfs_ioctl_vol_args *vol_args;
1868 struct btrfs_trans_handle *trans;
1869 int namelen;
1870 int ret;
1871 int err = 0;
1872
1873 vol_args = memdup_user(arg, sizeof(*vol_args));
1874 if (IS_ERR(vol_args))
1875 return PTR_ERR(vol_args);
1876
1877 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1878 namelen = strlen(vol_args->name);
1879 if (strchr(vol_args->name, '/') ||
1880 strncmp(vol_args->name, "..", namelen) == 0) {
1881 err = -EINVAL;
1882 goto out;
1883 }
1884
1885 err = mnt_want_write_file(file);
1886 if (err)
1887 goto out;
1888
1889 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
1890 dentry = lookup_one_len(vol_args->name, parent, namelen);
1891 if (IS_ERR(dentry)) {
1892 err = PTR_ERR(dentry);
1893 goto out_unlock_dir;
1894 }
1895
1896 if (!dentry->d_inode) {
1897 err = -ENOENT;
1898 goto out_dput;
1899 }
1900
1901 inode = dentry->d_inode;
1902 dest = BTRFS_I(inode)->root;
1903 if (!capable(CAP_SYS_ADMIN)){
1904 /*
1905 * Regular user. Only allow this with a special mount
1906 * option, when the user has write+exec access to the
1907 * subvol root, and when rmdir(2) would have been
1908 * allowed.
1909 *
1910 * Note that this is _not_ check that the subvol is
1911 * empty or doesn't contain data that we wouldn't
1912 * otherwise be able to delete.
1913 *
1914 * Users who want to delete empty subvols should try
1915 * rmdir(2).
1916 */
1917 err = -EPERM;
1918 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1919 goto out_dput;
1920
1921 /*
1922 * Do not allow deletion if the parent dir is the same
1923 * as the dir to be deleted. That means the ioctl
1924 * must be called on the dentry referencing the root
1925 * of the subvol, not a random directory contained
1926 * within it.
1927 */
1928 err = -EINVAL;
1929 if (root == dest)
1930 goto out_dput;
1931
1932 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
1933 if (err)
1934 goto out_dput;
1935
1936 /* check if subvolume may be deleted by a non-root user */
1937 err = btrfs_may_delete(dir, dentry, 1);
1938 if (err)
1939 goto out_dput;
1940 }
1941
1942 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1943 err = -EINVAL;
1944 goto out_dput;
1945 }
1946
1947 mutex_lock(&inode->i_mutex);
1948 err = d_invalidate(dentry);
1949 if (err)
1950 goto out_unlock;
1951
1952 down_write(&root->fs_info->subvol_sem);
1953
1954 err = may_destroy_subvol(dest);
1955 if (err)
1956 goto out_up_write;
1957
1958 trans = btrfs_start_transaction(root, 0);
1959 if (IS_ERR(trans)) {
1960 err = PTR_ERR(trans);
1961 goto out_up_write;
1962 }
1963 trans->block_rsv = &root->fs_info->global_block_rsv;
1964
1965 ret = btrfs_unlink_subvol(trans, root, dir,
1966 dest->root_key.objectid,
1967 dentry->d_name.name,
1968 dentry->d_name.len);
1969 BUG_ON(ret);
1970
1971 btrfs_record_root_in_trans(trans, dest);
1972
1973 memset(&dest->root_item.drop_progress, 0,
1974 sizeof(dest->root_item.drop_progress));
1975 dest->root_item.drop_level = 0;
1976 btrfs_set_root_refs(&dest->root_item, 0);
1977
1978 if (!xchg(&dest->orphan_item_inserted, 1)) {
1979 ret = btrfs_insert_orphan_item(trans,
1980 root->fs_info->tree_root,
1981 dest->root_key.objectid);
1982 BUG_ON(ret);
1983 }
1984
1985 ret = btrfs_end_transaction(trans, root);
1986 BUG_ON(ret);
1987 inode->i_flags |= S_DEAD;
1988 out_up_write:
1989 up_write(&root->fs_info->subvol_sem);
1990 out_unlock:
1991 mutex_unlock(&inode->i_mutex);
1992 if (!err) {
1993 shrink_dcache_sb(root->fs_info->sb);
1994 btrfs_invalidate_inodes(dest);
1995 d_delete(dentry);
1996 }
1997 out_dput:
1998 dput(dentry);
1999 out_unlock_dir:
2000 mutex_unlock(&dir->i_mutex);
2001 mnt_drop_write_file(file);
2002 out:
2003 kfree(vol_args);
2004 return err;
2005 }
2006
2007 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2008 {
2009 struct inode *inode = fdentry(file)->d_inode;
2010 struct btrfs_root *root = BTRFS_I(inode)->root;
2011 struct btrfs_ioctl_defrag_range_args *range;
2012 int ret;
2013
2014 if (btrfs_root_readonly(root))
2015 return -EROFS;
2016
2017 ret = mnt_want_write_file(file);
2018 if (ret)
2019 return ret;
2020
2021 switch (inode->i_mode & S_IFMT) {
2022 case S_IFDIR:
2023 if (!capable(CAP_SYS_ADMIN)) {
2024 ret = -EPERM;
2025 goto out;
2026 }
2027 ret = btrfs_defrag_root(root, 0);
2028 if (ret)
2029 goto out;
2030 ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
2031 break;
2032 case S_IFREG:
2033 if (!(file->f_mode & FMODE_WRITE)) {
2034 ret = -EINVAL;
2035 goto out;
2036 }
2037
2038 range = kzalloc(sizeof(*range), GFP_KERNEL);
2039 if (!range) {
2040 ret = -ENOMEM;
2041 goto out;
2042 }
2043
2044 if (argp) {
2045 if (copy_from_user(range, argp,
2046 sizeof(*range))) {
2047 ret = -EFAULT;
2048 kfree(range);
2049 goto out;
2050 }
2051 /* compression requires us to start the IO */
2052 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2053 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2054 range->extent_thresh = (u32)-1;
2055 }
2056 } else {
2057 /* the rest are all set to zero by kzalloc */
2058 range->len = (u64)-1;
2059 }
2060 ret = btrfs_defrag_file(fdentry(file)->d_inode, file,
2061 range, 0, 0);
2062 if (ret > 0)
2063 ret = 0;
2064 kfree(range);
2065 break;
2066 default:
2067 ret = -EINVAL;
2068 }
2069 out:
2070 mnt_drop_write_file(file);
2071 return ret;
2072 }
2073
2074 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2075 {
2076 struct btrfs_ioctl_vol_args *vol_args;
2077 int ret;
2078
2079 if (!capable(CAP_SYS_ADMIN))
2080 return -EPERM;
2081
2082 mutex_lock(&root->fs_info->volume_mutex);
2083 if (root->fs_info->balance_ctl) {
2084 printk(KERN_INFO "btrfs: balance in progress\n");
2085 ret = -EINVAL;
2086 goto out;
2087 }
2088
2089 vol_args = memdup_user(arg, sizeof(*vol_args));
2090 if (IS_ERR(vol_args)) {
2091 ret = PTR_ERR(vol_args);
2092 goto out;
2093 }
2094
2095 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2096 ret = btrfs_init_new_device(root, vol_args->name);
2097
2098 kfree(vol_args);
2099 out:
2100 mutex_unlock(&root->fs_info->volume_mutex);
2101 return ret;
2102 }
2103
2104 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
2105 {
2106 struct btrfs_ioctl_vol_args *vol_args;
2107 int ret;
2108
2109 if (!capable(CAP_SYS_ADMIN))
2110 return -EPERM;
2111
2112 if (root->fs_info->sb->s_flags & MS_RDONLY)
2113 return -EROFS;
2114
2115 mutex_lock(&root->fs_info->volume_mutex);
2116 if (root->fs_info->balance_ctl) {
2117 printk(KERN_INFO "btrfs: balance in progress\n");
2118 ret = -EINVAL;
2119 goto out;
2120 }
2121
2122 vol_args = memdup_user(arg, sizeof(*vol_args));
2123 if (IS_ERR(vol_args)) {
2124 ret = PTR_ERR(vol_args);
2125 goto out;
2126 }
2127
2128 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2129 ret = btrfs_rm_device(root, vol_args->name);
2130
2131 kfree(vol_args);
2132 out:
2133 mutex_unlock(&root->fs_info->volume_mutex);
2134 return ret;
2135 }
2136
2137 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2138 {
2139 struct btrfs_ioctl_fs_info_args *fi_args;
2140 struct btrfs_device *device;
2141 struct btrfs_device *next;
2142 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2143 int ret = 0;
2144
2145 if (!capable(CAP_SYS_ADMIN))
2146 return -EPERM;
2147
2148 fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2149 if (!fi_args)
2150 return -ENOMEM;
2151
2152 fi_args->num_devices = fs_devices->num_devices;
2153 memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2154
2155 mutex_lock(&fs_devices->device_list_mutex);
2156 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
2157 if (device->devid > fi_args->max_id)
2158 fi_args->max_id = device->devid;
2159 }
2160 mutex_unlock(&fs_devices->device_list_mutex);
2161
2162 if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2163 ret = -EFAULT;
2164
2165 kfree(fi_args);
2166 return ret;
2167 }
2168
2169 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2170 {
2171 struct btrfs_ioctl_dev_info_args *di_args;
2172 struct btrfs_device *dev;
2173 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2174 int ret = 0;
2175 char *s_uuid = NULL;
2176 char empty_uuid[BTRFS_UUID_SIZE] = {0};
2177
2178 if (!capable(CAP_SYS_ADMIN))
2179 return -EPERM;
2180
2181 di_args = memdup_user(arg, sizeof(*di_args));
2182 if (IS_ERR(di_args))
2183 return PTR_ERR(di_args);
2184
2185 if (memcmp(empty_uuid, di_args->uuid, BTRFS_UUID_SIZE) != 0)
2186 s_uuid = di_args->uuid;
2187
2188 mutex_lock(&fs_devices->device_list_mutex);
2189 dev = btrfs_find_device(root, di_args->devid, s_uuid, NULL);
2190 mutex_unlock(&fs_devices->device_list_mutex);
2191
2192 if (!dev) {
2193 ret = -ENODEV;
2194 goto out;
2195 }
2196
2197 di_args->devid = dev->devid;
2198 di_args->bytes_used = dev->bytes_used;
2199 di_args->total_bytes = dev->total_bytes;
2200 memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2201 strncpy(di_args->path, dev->name, sizeof(di_args->path));
2202
2203 out:
2204 if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2205 ret = -EFAULT;
2206
2207 kfree(di_args);
2208 return ret;
2209 }
2210
2211 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
2212 u64 off, u64 olen, u64 destoff)
2213 {
2214 struct inode *inode = fdentry(file)->d_inode;
2215 struct btrfs_root *root = BTRFS_I(inode)->root;
2216 struct file *src_file;
2217 struct inode *src;
2218 struct btrfs_trans_handle *trans;
2219 struct btrfs_path *path;
2220 struct extent_buffer *leaf;
2221 char *buf;
2222 struct btrfs_key key;
2223 u32 nritems;
2224 int slot;
2225 int ret;
2226 u64 len = olen;
2227 u64 bs = root->fs_info->sb->s_blocksize;
2228 u64 hint_byte;
2229
2230 /*
2231 * TODO:
2232 * - split compressed inline extents. annoying: we need to
2233 * decompress into destination's address_space (the file offset
2234 * may change, so source mapping won't do), then recompress (or
2235 * otherwise reinsert) a subrange.
2236 * - allow ranges within the same file to be cloned (provided
2237 * they don't overlap)?
2238 */
2239
2240 /* the destination must be opened for writing */
2241 if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
2242 return -EINVAL;
2243
2244 if (btrfs_root_readonly(root))
2245 return -EROFS;
2246
2247 ret = mnt_want_write_file(file);
2248 if (ret)
2249 return ret;
2250
2251 src_file = fget(srcfd);
2252 if (!src_file) {
2253 ret = -EBADF;
2254 goto out_drop_write;
2255 }
2256
2257 src = src_file->f_dentry->d_inode;
2258
2259 ret = -EINVAL;
2260 if (src == inode)
2261 goto out_fput;
2262
2263 /* the src must be open for reading */
2264 if (!(src_file->f_mode & FMODE_READ))
2265 goto out_fput;
2266
2267 /* don't make the dst file partly checksummed */
2268 if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
2269 (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
2270 goto out_fput;
2271
2272 ret = -EISDIR;
2273 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
2274 goto out_fput;
2275
2276 ret = -EXDEV;
2277 if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
2278 goto out_fput;
2279
2280 ret = -ENOMEM;
2281 buf = vmalloc(btrfs_level_size(root, 0));
2282 if (!buf)
2283 goto out_fput;
2284
2285 path = btrfs_alloc_path();
2286 if (!path) {
2287 vfree(buf);
2288 goto out_fput;
2289 }
2290 path->reada = 2;
2291
2292 if (inode < src) {
2293 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
2294 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
2295 } else {
2296 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
2297 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
2298 }
2299
2300 /* determine range to clone */
2301 ret = -EINVAL;
2302 if (off + len > src->i_size || off + len < off)
2303 goto out_unlock;
2304 if (len == 0)
2305 olen = len = src->i_size - off;
2306 /* if we extend to eof, continue to block boundary */
2307 if (off + len == src->i_size)
2308 len = ALIGN(src->i_size, bs) - off;
2309
2310 /* verify the end result is block aligned */
2311 if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
2312 !IS_ALIGNED(destoff, bs))
2313 goto out_unlock;
2314
2315 if (destoff > inode->i_size) {
2316 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
2317 if (ret)
2318 goto out_unlock;
2319 }
2320
2321 /* truncate page cache pages from target inode range */
2322 truncate_inode_pages_range(&inode->i_data, destoff,
2323 PAGE_CACHE_ALIGN(destoff + len) - 1);
2324
2325 /* do any pending delalloc/csum calc on src, one way or
2326 another, and lock file content */
2327 while (1) {
2328 struct btrfs_ordered_extent *ordered;
2329 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2330 ordered = btrfs_lookup_first_ordered_extent(src, off+len);
2331 if (!ordered &&
2332 !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len,
2333 EXTENT_DELALLOC, 0, NULL))
2334 break;
2335 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2336 if (ordered)
2337 btrfs_put_ordered_extent(ordered);
2338 btrfs_wait_ordered_range(src, off, len);
2339 }
2340
2341 /* clone data */
2342 key.objectid = btrfs_ino(src);
2343 key.type = BTRFS_EXTENT_DATA_KEY;
2344 key.offset = 0;
2345
2346 while (1) {
2347 /*
2348 * note the key will change type as we walk through the
2349 * tree.
2350 */
2351 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2352 if (ret < 0)
2353 goto out;
2354
2355 nritems = btrfs_header_nritems(path->nodes[0]);
2356 if (path->slots[0] >= nritems) {
2357 ret = btrfs_next_leaf(root, path);
2358 if (ret < 0)
2359 goto out;
2360 if (ret > 0)
2361 break;
2362 nritems = btrfs_header_nritems(path->nodes[0]);
2363 }
2364 leaf = path->nodes[0];
2365 slot = path->slots[0];
2366
2367 btrfs_item_key_to_cpu(leaf, &key, slot);
2368 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
2369 key.objectid != btrfs_ino(src))
2370 break;
2371
2372 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
2373 struct btrfs_file_extent_item *extent;
2374 int type;
2375 u32 size;
2376 struct btrfs_key new_key;
2377 u64 disko = 0, diskl = 0;
2378 u64 datao = 0, datal = 0;
2379 u8 comp;
2380 u64 endoff;
2381
2382 size = btrfs_item_size_nr(leaf, slot);
2383 read_extent_buffer(leaf, buf,
2384 btrfs_item_ptr_offset(leaf, slot),
2385 size);
2386
2387 extent = btrfs_item_ptr(leaf, slot,
2388 struct btrfs_file_extent_item);
2389 comp = btrfs_file_extent_compression(leaf, extent);
2390 type = btrfs_file_extent_type(leaf, extent);
2391 if (type == BTRFS_FILE_EXTENT_REG ||
2392 type == BTRFS_FILE_EXTENT_PREALLOC) {
2393 disko = btrfs_file_extent_disk_bytenr(leaf,
2394 extent);
2395 diskl = btrfs_file_extent_disk_num_bytes(leaf,
2396 extent);
2397 datao = btrfs_file_extent_offset(leaf, extent);
2398 datal = btrfs_file_extent_num_bytes(leaf,
2399 extent);
2400 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2401 /* take upper bound, may be compressed */
2402 datal = btrfs_file_extent_ram_bytes(leaf,
2403 extent);
2404 }
2405 btrfs_release_path(path);
2406
2407 if (key.offset + datal <= off ||
2408 key.offset >= off+len)
2409 goto next;
2410
2411 memcpy(&new_key, &key, sizeof(new_key));
2412 new_key.objectid = btrfs_ino(inode);
2413 if (off <= key.offset)
2414 new_key.offset = key.offset + destoff - off;
2415 else
2416 new_key.offset = destoff;
2417
2418 /*
2419 * 1 - adjusting old extent (we may have to split it)
2420 * 1 - add new extent
2421 * 1 - inode update
2422 */
2423 trans = btrfs_start_transaction(root, 3);
2424 if (IS_ERR(trans)) {
2425 ret = PTR_ERR(trans);
2426 goto out;
2427 }
2428
2429 if (type == BTRFS_FILE_EXTENT_REG ||
2430 type == BTRFS_FILE_EXTENT_PREALLOC) {
2431 /*
2432 * a | --- range to clone ---| b
2433 * | ------------- extent ------------- |
2434 */
2435
2436 /* substract range b */
2437 if (key.offset + datal > off + len)
2438 datal = off + len - key.offset;
2439
2440 /* substract range a */
2441 if (off > key.offset) {
2442 datao += off - key.offset;
2443 datal -= off - key.offset;
2444 }
2445
2446 ret = btrfs_drop_extents(trans, inode,
2447 new_key.offset,
2448 new_key.offset + datal,
2449 &hint_byte, 1);
2450 BUG_ON(ret);
2451
2452 ret = btrfs_insert_empty_item(trans, root, path,
2453 &new_key, size);
2454 BUG_ON(ret);
2455
2456 leaf = path->nodes[0];
2457 slot = path->slots[0];
2458 write_extent_buffer(leaf, buf,
2459 btrfs_item_ptr_offset(leaf, slot),
2460 size);
2461
2462 extent = btrfs_item_ptr(leaf, slot,
2463 struct btrfs_file_extent_item);
2464
2465 /* disko == 0 means it's a hole */
2466 if (!disko)
2467 datao = 0;
2468
2469 btrfs_set_file_extent_offset(leaf, extent,
2470 datao);
2471 btrfs_set_file_extent_num_bytes(leaf, extent,
2472 datal);
2473 if (disko) {
2474 inode_add_bytes(inode, datal);
2475 ret = btrfs_inc_extent_ref(trans, root,
2476 disko, diskl, 0,
2477 root->root_key.objectid,
2478 btrfs_ino(inode),
2479 new_key.offset - datao,
2480 0);
2481 BUG_ON(ret);
2482 }
2483 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2484 u64 skip = 0;
2485 u64 trim = 0;
2486 if (off > key.offset) {
2487 skip = off - key.offset;
2488 new_key.offset += skip;
2489 }
2490
2491 if (key.offset + datal > off+len)
2492 trim = key.offset + datal - (off+len);
2493
2494 if (comp && (skip || trim)) {
2495 ret = -EINVAL;
2496 btrfs_end_transaction(trans, root);
2497 goto out;
2498 }
2499 size -= skip + trim;
2500 datal -= skip + trim;
2501
2502 ret = btrfs_drop_extents(trans, inode,
2503 new_key.offset,
2504 new_key.offset + datal,
2505 &hint_byte, 1);
2506 BUG_ON(ret);
2507
2508 ret = btrfs_insert_empty_item(trans, root, path,
2509 &new_key, size);
2510 BUG_ON(ret);
2511
2512 if (skip) {
2513 u32 start =
2514 btrfs_file_extent_calc_inline_size(0);
2515 memmove(buf+start, buf+start+skip,
2516 datal);
2517 }
2518
2519 leaf = path->nodes[0];
2520 slot = path->slots[0];
2521 write_extent_buffer(leaf, buf,
2522 btrfs_item_ptr_offset(leaf, slot),
2523 size);
2524 inode_add_bytes(inode, datal);
2525 }
2526
2527 btrfs_mark_buffer_dirty(leaf);
2528 btrfs_release_path(path);
2529
2530 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2531
2532 /*
2533 * we round up to the block size at eof when
2534 * determining which extents to clone above,
2535 * but shouldn't round up the file size
2536 */
2537 endoff = new_key.offset + datal;
2538 if (endoff > destoff+olen)
2539 endoff = destoff+olen;
2540 if (endoff > inode->i_size)
2541 btrfs_i_size_write(inode, endoff);
2542
2543 ret = btrfs_update_inode(trans, root, inode);
2544 BUG_ON(ret);
2545 btrfs_end_transaction(trans, root);
2546 }
2547 next:
2548 btrfs_release_path(path);
2549 key.offset++;
2550 }
2551 ret = 0;
2552 out:
2553 btrfs_release_path(path);
2554 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2555 out_unlock:
2556 mutex_unlock(&src->i_mutex);
2557 mutex_unlock(&inode->i_mutex);
2558 vfree(buf);
2559 btrfs_free_path(path);
2560 out_fput:
2561 fput(src_file);
2562 out_drop_write:
2563 mnt_drop_write_file(file);
2564 return ret;
2565 }
2566
2567 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2568 {
2569 struct btrfs_ioctl_clone_range_args args;
2570
2571 if (copy_from_user(&args, argp, sizeof(args)))
2572 return -EFAULT;
2573 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2574 args.src_length, args.dest_offset);
2575 }
2576
2577 /*
2578 * there are many ways the trans_start and trans_end ioctls can lead
2579 * to deadlocks. They should only be used by applications that
2580 * basically own the machine, and have a very in depth understanding
2581 * of all the possible deadlocks and enospc problems.
2582 */
2583 static long btrfs_ioctl_trans_start(struct file *file)
2584 {
2585 struct inode *inode = fdentry(file)->d_inode;
2586 struct btrfs_root *root = BTRFS_I(inode)->root;
2587 struct btrfs_trans_handle *trans;
2588 int ret;
2589
2590 ret = -EPERM;
2591 if (!capable(CAP_SYS_ADMIN))
2592 goto out;
2593
2594 ret = -EINPROGRESS;
2595 if (file->private_data)
2596 goto out;
2597
2598 ret = -EROFS;
2599 if (btrfs_root_readonly(root))
2600 goto out;
2601
2602 ret = mnt_want_write_file(file);
2603 if (ret)
2604 goto out;
2605
2606 atomic_inc(&root->fs_info->open_ioctl_trans);
2607
2608 ret = -ENOMEM;
2609 trans = btrfs_start_ioctl_transaction(root);
2610 if (IS_ERR(trans))
2611 goto out_drop;
2612
2613 file->private_data = trans;
2614 return 0;
2615
2616 out_drop:
2617 atomic_dec(&root->fs_info->open_ioctl_trans);
2618 mnt_drop_write_file(file);
2619 out:
2620 return ret;
2621 }
2622
2623 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2624 {
2625 struct inode *inode = fdentry(file)->d_inode;
2626 struct btrfs_root *root = BTRFS_I(inode)->root;
2627 struct btrfs_root *new_root;
2628 struct btrfs_dir_item *di;
2629 struct btrfs_trans_handle *trans;
2630 struct btrfs_path *path;
2631 struct btrfs_key location;
2632 struct btrfs_disk_key disk_key;
2633 struct btrfs_super_block *disk_super;
2634 u64 features;
2635 u64 objectid = 0;
2636 u64 dir_id;
2637
2638 if (!capable(CAP_SYS_ADMIN))
2639 return -EPERM;
2640
2641 if (copy_from_user(&objectid, argp, sizeof(objectid)))
2642 return -EFAULT;
2643
2644 if (!objectid)
2645 objectid = root->root_key.objectid;
2646
2647 location.objectid = objectid;
2648 location.type = BTRFS_ROOT_ITEM_KEY;
2649 location.offset = (u64)-1;
2650
2651 new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2652 if (IS_ERR(new_root))
2653 return PTR_ERR(new_root);
2654
2655 if (btrfs_root_refs(&new_root->root_item) == 0)
2656 return -ENOENT;
2657
2658 path = btrfs_alloc_path();
2659 if (!path)
2660 return -ENOMEM;
2661 path->leave_spinning = 1;
2662
2663 trans = btrfs_start_transaction(root, 1);
2664 if (IS_ERR(trans)) {
2665 btrfs_free_path(path);
2666 return PTR_ERR(trans);
2667 }
2668
2669 dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
2670 di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2671 dir_id, "default", 7, 1);
2672 if (IS_ERR_OR_NULL(di)) {
2673 btrfs_free_path(path);
2674 btrfs_end_transaction(trans, root);
2675 printk(KERN_ERR "Umm, you don't have the default dir item, "
2676 "this isn't going to work\n");
2677 return -ENOENT;
2678 }
2679
2680 btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2681 btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2682 btrfs_mark_buffer_dirty(path->nodes[0]);
2683 btrfs_free_path(path);
2684
2685 disk_super = root->fs_info->super_copy;
2686 features = btrfs_super_incompat_flags(disk_super);
2687 if (!(features & BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)) {
2688 features |= BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL;
2689 btrfs_set_super_incompat_flags(disk_super, features);
2690 }
2691 btrfs_end_transaction(trans, root);
2692
2693 return 0;
2694 }
2695
2696 static void get_block_group_info(struct list_head *groups_list,
2697 struct btrfs_ioctl_space_info *space)
2698 {
2699 struct btrfs_block_group_cache *block_group;
2700
2701 space->total_bytes = 0;
2702 space->used_bytes = 0;
2703 space->flags = 0;
2704 list_for_each_entry(block_group, groups_list, list) {
2705 space->flags = block_group->flags;
2706 space->total_bytes += block_group->key.offset;
2707 space->used_bytes +=
2708 btrfs_block_group_used(&block_group->item);
2709 }
2710 }
2711
2712 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
2713 {
2714 struct btrfs_ioctl_space_args space_args;
2715 struct btrfs_ioctl_space_info space;
2716 struct btrfs_ioctl_space_info *dest;
2717 struct btrfs_ioctl_space_info *dest_orig;
2718 struct btrfs_ioctl_space_info __user *user_dest;
2719 struct btrfs_space_info *info;
2720 u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2721 BTRFS_BLOCK_GROUP_SYSTEM,
2722 BTRFS_BLOCK_GROUP_METADATA,
2723 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2724 int num_types = 4;
2725 int alloc_size;
2726 int ret = 0;
2727 u64 slot_count = 0;
2728 int i, c;
2729
2730 if (copy_from_user(&space_args,
2731 (struct btrfs_ioctl_space_args __user *)arg,
2732 sizeof(space_args)))
2733 return -EFAULT;
2734
2735 for (i = 0; i < num_types; i++) {
2736 struct btrfs_space_info *tmp;
2737
2738 info = NULL;
2739 rcu_read_lock();
2740 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2741 list) {
2742 if (tmp->flags == types[i]) {
2743 info = tmp;
2744 break;
2745 }
2746 }
2747 rcu_read_unlock();
2748
2749 if (!info)
2750 continue;
2751
2752 down_read(&info->groups_sem);
2753 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2754 if (!list_empty(&info->block_groups[c]))
2755 slot_count++;
2756 }
2757 up_read(&info->groups_sem);
2758 }
2759
2760 /* space_slots == 0 means they are asking for a count */
2761 if (space_args.space_slots == 0) {
2762 space_args.total_spaces = slot_count;
2763 goto out;
2764 }
2765
2766 slot_count = min_t(u64, space_args.space_slots, slot_count);
2767
2768 alloc_size = sizeof(*dest) * slot_count;
2769
2770 /* we generally have at most 6 or so space infos, one for each raid
2771 * level. So, a whole page should be more than enough for everyone
2772 */
2773 if (alloc_size > PAGE_CACHE_SIZE)
2774 return -ENOMEM;
2775
2776 space_args.total_spaces = 0;
2777 dest = kmalloc(alloc_size, GFP_NOFS);
2778 if (!dest)
2779 return -ENOMEM;
2780 dest_orig = dest;
2781
2782 /* now we have a buffer to copy into */
2783 for (i = 0; i < num_types; i++) {
2784 struct btrfs_space_info *tmp;
2785
2786 if (!slot_count)
2787 break;
2788
2789 info = NULL;
2790 rcu_read_lock();
2791 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2792 list) {
2793 if (tmp->flags == types[i]) {
2794 info = tmp;
2795 break;
2796 }
2797 }
2798 rcu_read_unlock();
2799
2800 if (!info)
2801 continue;
2802 down_read(&info->groups_sem);
2803 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2804 if (!list_empty(&info->block_groups[c])) {
2805 get_block_group_info(&info->block_groups[c],
2806 &space);
2807 memcpy(dest, &space, sizeof(space));
2808 dest++;
2809 space_args.total_spaces++;
2810 slot_count--;
2811 }
2812 if (!slot_count)
2813 break;
2814 }
2815 up_read(&info->groups_sem);
2816 }
2817
2818 user_dest = (struct btrfs_ioctl_space_info *)
2819 (arg + sizeof(struct btrfs_ioctl_space_args));
2820
2821 if (copy_to_user(user_dest, dest_orig, alloc_size))
2822 ret = -EFAULT;
2823
2824 kfree(dest_orig);
2825 out:
2826 if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
2827 ret = -EFAULT;
2828
2829 return ret;
2830 }
2831
2832 /*
2833 * there are many ways the trans_start and trans_end ioctls can lead
2834 * to deadlocks. They should only be used by applications that
2835 * basically own the machine, and have a very in depth understanding
2836 * of all the possible deadlocks and enospc problems.
2837 */
2838 long btrfs_ioctl_trans_end(struct file *file)
2839 {
2840 struct inode *inode = fdentry(file)->d_inode;
2841 struct btrfs_root *root = BTRFS_I(inode)->root;
2842 struct btrfs_trans_handle *trans;
2843
2844 trans = file->private_data;
2845 if (!trans)
2846 return -EINVAL;
2847 file->private_data = NULL;
2848
2849 btrfs_end_transaction(trans, root);
2850
2851 atomic_dec(&root->fs_info->open_ioctl_trans);
2852
2853 mnt_drop_write_file(file);
2854 return 0;
2855 }
2856
2857 static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp)
2858 {
2859 struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2860 struct btrfs_trans_handle *trans;
2861 u64 transid;
2862 int ret;
2863
2864 trans = btrfs_start_transaction(root, 0);
2865 if (IS_ERR(trans))
2866 return PTR_ERR(trans);
2867 transid = trans->transid;
2868 ret = btrfs_commit_transaction_async(trans, root, 0);
2869 if (ret) {
2870 btrfs_end_transaction(trans, root);
2871 return ret;
2872 }
2873
2874 if (argp)
2875 if (copy_to_user(argp, &transid, sizeof(transid)))
2876 return -EFAULT;
2877 return 0;
2878 }
2879
2880 static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp)
2881 {
2882 struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2883 u64 transid;
2884
2885 if (argp) {
2886 if (copy_from_user(&transid, argp, sizeof(transid)))
2887 return -EFAULT;
2888 } else {
2889 transid = 0; /* current trans */
2890 }
2891 return btrfs_wait_for_commit(root, transid);
2892 }
2893
2894 static long btrfs_ioctl_scrub(struct btrfs_root *root, void __user *arg)
2895 {
2896 int ret;
2897 struct btrfs_ioctl_scrub_args *sa;
2898
2899 if (!capable(CAP_SYS_ADMIN))
2900 return -EPERM;
2901
2902 sa = memdup_user(arg, sizeof(*sa));
2903 if (IS_ERR(sa))
2904 return PTR_ERR(sa);
2905
2906 ret = btrfs_scrub_dev(root, sa->devid, sa->start, sa->end,
2907 &sa->progress, sa->flags & BTRFS_SCRUB_READONLY);
2908
2909 if (copy_to_user(arg, sa, sizeof(*sa)))
2910 ret = -EFAULT;
2911
2912 kfree(sa);
2913 return ret;
2914 }
2915
2916 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
2917 {
2918 if (!capable(CAP_SYS_ADMIN))
2919 return -EPERM;
2920
2921 return btrfs_scrub_cancel(root);
2922 }
2923
2924 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
2925 void __user *arg)
2926 {
2927 struct btrfs_ioctl_scrub_args *sa;
2928 int ret;
2929
2930 if (!capable(CAP_SYS_ADMIN))
2931 return -EPERM;
2932
2933 sa = memdup_user(arg, sizeof(*sa));
2934 if (IS_ERR(sa))
2935 return PTR_ERR(sa);
2936
2937 ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
2938
2939 if (copy_to_user(arg, sa, sizeof(*sa)))
2940 ret = -EFAULT;
2941
2942 kfree(sa);
2943 return ret;
2944 }
2945
2946 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
2947 {
2948 int ret = 0;
2949 int i;
2950 u64 rel_ptr;
2951 int size;
2952 struct btrfs_ioctl_ino_path_args *ipa = NULL;
2953 struct inode_fs_paths *ipath = NULL;
2954 struct btrfs_path *path;
2955
2956 if (!capable(CAP_SYS_ADMIN))
2957 return -EPERM;
2958
2959 path = btrfs_alloc_path();
2960 if (!path) {
2961 ret = -ENOMEM;
2962 goto out;
2963 }
2964
2965 ipa = memdup_user(arg, sizeof(*ipa));
2966 if (IS_ERR(ipa)) {
2967 ret = PTR_ERR(ipa);
2968 ipa = NULL;
2969 goto out;
2970 }
2971
2972 size = min_t(u32, ipa->size, 4096);
2973 ipath = init_ipath(size, root, path);
2974 if (IS_ERR(ipath)) {
2975 ret = PTR_ERR(ipath);
2976 ipath = NULL;
2977 goto out;
2978 }
2979
2980 ret = paths_from_inode(ipa->inum, ipath);
2981 if (ret < 0)
2982 goto out;
2983
2984 for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
2985 rel_ptr = ipath->fspath->val[i] -
2986 (u64)(unsigned long)ipath->fspath->val;
2987 ipath->fspath->val[i] = rel_ptr;
2988 }
2989
2990 ret = copy_to_user((void *)(unsigned long)ipa->fspath,
2991 (void *)(unsigned long)ipath->fspath, size);
2992 if (ret) {
2993 ret = -EFAULT;
2994 goto out;
2995 }
2996
2997 out:
2998 btrfs_free_path(path);
2999 free_ipath(ipath);
3000 kfree(ipa);
3001
3002 return ret;
3003 }
3004
3005 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
3006 {
3007 struct btrfs_data_container *inodes = ctx;
3008 const size_t c = 3 * sizeof(u64);
3009
3010 if (inodes->bytes_left >= c) {
3011 inodes->bytes_left -= c;
3012 inodes->val[inodes->elem_cnt] = inum;
3013 inodes->val[inodes->elem_cnt + 1] = offset;
3014 inodes->val[inodes->elem_cnt + 2] = root;
3015 inodes->elem_cnt += 3;
3016 } else {
3017 inodes->bytes_missing += c - inodes->bytes_left;
3018 inodes->bytes_left = 0;
3019 inodes->elem_missed += 3;
3020 }
3021
3022 return 0;
3023 }
3024
3025 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
3026 void __user *arg)
3027 {
3028 int ret = 0;
3029 int size;
3030 u64 extent_item_pos;
3031 struct btrfs_ioctl_logical_ino_args *loi;
3032 struct btrfs_data_container *inodes = NULL;
3033 struct btrfs_path *path = NULL;
3034 struct btrfs_key key;
3035
3036 if (!capable(CAP_SYS_ADMIN))
3037 return -EPERM;
3038
3039 loi = memdup_user(arg, sizeof(*loi));
3040 if (IS_ERR(loi)) {
3041 ret = PTR_ERR(loi);
3042 loi = NULL;
3043 goto out;
3044 }
3045
3046 path = btrfs_alloc_path();
3047 if (!path) {
3048 ret = -ENOMEM;
3049 goto out;
3050 }
3051
3052 size = min_t(u32, loi->size, 4096);
3053 inodes = init_data_container(size);
3054 if (IS_ERR(inodes)) {
3055 ret = PTR_ERR(inodes);
3056 inodes = NULL;
3057 goto out;
3058 }
3059
3060 ret = extent_from_logical(root->fs_info, loi->logical, path, &key);
3061 btrfs_release_path(path);
3062
3063 if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK)
3064 ret = -ENOENT;
3065 if (ret < 0)
3066 goto out;
3067
3068 extent_item_pos = loi->logical - key.objectid;
3069 ret = iterate_extent_inodes(root->fs_info, path, key.objectid,
3070 extent_item_pos, build_ino_list,
3071 inodes);
3072
3073 if (ret < 0)
3074 goto out;
3075
3076 ret = copy_to_user((void *)(unsigned long)loi->inodes,
3077 (void *)(unsigned long)inodes, size);
3078 if (ret)
3079 ret = -EFAULT;
3080
3081 out:
3082 btrfs_free_path(path);
3083 kfree(inodes);
3084 kfree(loi);
3085
3086 return ret;
3087 }
3088
3089 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
3090 struct btrfs_ioctl_balance_args *bargs)
3091 {
3092 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3093
3094 bargs->flags = bctl->flags;
3095
3096 if (atomic_read(&fs_info->balance_running))
3097 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
3098 if (atomic_read(&fs_info->balance_pause_req))
3099 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
3100 if (atomic_read(&fs_info->balance_cancel_req))
3101 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
3102
3103 memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
3104 memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
3105 memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
3106
3107 if (lock) {
3108 spin_lock(&fs_info->balance_lock);
3109 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3110 spin_unlock(&fs_info->balance_lock);
3111 } else {
3112 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3113 }
3114 }
3115
3116 static long btrfs_ioctl_balance(struct btrfs_root *root, void __user *arg)
3117 {
3118 struct btrfs_fs_info *fs_info = root->fs_info;
3119 struct btrfs_ioctl_balance_args *bargs;
3120 struct btrfs_balance_control *bctl;
3121 int ret;
3122
3123 if (!capable(CAP_SYS_ADMIN))
3124 return -EPERM;
3125
3126 if (fs_info->sb->s_flags & MS_RDONLY)
3127 return -EROFS;
3128
3129 mutex_lock(&fs_info->volume_mutex);
3130 mutex_lock(&fs_info->balance_mutex);
3131
3132 if (arg) {
3133 bargs = memdup_user(arg, sizeof(*bargs));
3134 if (IS_ERR(bargs)) {
3135 ret = PTR_ERR(bargs);
3136 goto out;
3137 }
3138
3139 if (bargs->flags & BTRFS_BALANCE_RESUME) {
3140 if (!fs_info->balance_ctl) {
3141 ret = -ENOTCONN;
3142 goto out_bargs;
3143 }
3144
3145 bctl = fs_info->balance_ctl;
3146 spin_lock(&fs_info->balance_lock);
3147 bctl->flags |= BTRFS_BALANCE_RESUME;
3148 spin_unlock(&fs_info->balance_lock);
3149
3150 goto do_balance;
3151 }
3152 } else {
3153 bargs = NULL;
3154 }
3155
3156 if (fs_info->balance_ctl) {
3157 ret = -EINPROGRESS;
3158 goto out_bargs;
3159 }
3160
3161 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3162 if (!bctl) {
3163 ret = -ENOMEM;
3164 goto out_bargs;
3165 }
3166
3167 bctl->fs_info = fs_info;
3168 if (arg) {
3169 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
3170 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
3171 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
3172
3173 bctl->flags = bargs->flags;
3174 } else {
3175 /* balance everything - no filters */
3176 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
3177 }
3178
3179 do_balance:
3180 ret = btrfs_balance(bctl, bargs);
3181 /*
3182 * bctl is freed in __cancel_balance or in free_fs_info if
3183 * restriper was paused all the way until unmount
3184 */
3185 if (arg) {
3186 if (copy_to_user(arg, bargs, sizeof(*bargs)))
3187 ret = -EFAULT;
3188 }
3189
3190 out_bargs:
3191 kfree(bargs);
3192 out:
3193 mutex_unlock(&fs_info->balance_mutex);
3194 mutex_unlock(&fs_info->volume_mutex);
3195 return ret;
3196 }
3197
3198 static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
3199 {
3200 if (!capable(CAP_SYS_ADMIN))
3201 return -EPERM;
3202
3203 switch (cmd) {
3204 case BTRFS_BALANCE_CTL_PAUSE:
3205 return btrfs_pause_balance(root->fs_info);
3206 case BTRFS_BALANCE_CTL_CANCEL:
3207 return btrfs_cancel_balance(root->fs_info);
3208 }
3209
3210 return -EINVAL;
3211 }
3212
3213 static long btrfs_ioctl_balance_progress(struct btrfs_root *root,
3214 void __user *arg)
3215 {
3216 struct btrfs_fs_info *fs_info = root->fs_info;
3217 struct btrfs_ioctl_balance_args *bargs;
3218 int ret = 0;
3219
3220 if (!capable(CAP_SYS_ADMIN))
3221 return -EPERM;
3222
3223 mutex_lock(&fs_info->balance_mutex);
3224 if (!fs_info->balance_ctl) {
3225 ret = -ENOTCONN;
3226 goto out;
3227 }
3228
3229 bargs = kzalloc(sizeof(*bargs), GFP_NOFS);
3230 if (!bargs) {
3231 ret = -ENOMEM;
3232 goto out;
3233 }
3234
3235 update_ioctl_balance_args(fs_info, 1, bargs);
3236
3237 if (copy_to_user(arg, bargs, sizeof(*bargs)))
3238 ret = -EFAULT;
3239
3240 kfree(bargs);
3241 out:
3242 mutex_unlock(&fs_info->balance_mutex);
3243 return ret;
3244 }
3245
3246 long btrfs_ioctl(struct file *file, unsigned int
3247 cmd, unsigned long arg)
3248 {
3249 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3250 void __user *argp = (void __user *)arg;
3251
3252 switch (cmd) {
3253 case FS_IOC_GETFLAGS:
3254 return btrfs_ioctl_getflags(file, argp);
3255 case FS_IOC_SETFLAGS:
3256 return btrfs_ioctl_setflags(file, argp);
3257 case FS_IOC_GETVERSION:
3258 return btrfs_ioctl_getversion(file, argp);
3259 case FITRIM:
3260 return btrfs_ioctl_fitrim(file, argp);
3261 case BTRFS_IOC_SNAP_CREATE:
3262 return btrfs_ioctl_snap_create(file, argp, 0);
3263 case BTRFS_IOC_SNAP_CREATE_V2:
3264 return btrfs_ioctl_snap_create_v2(file, argp, 0);
3265 case BTRFS_IOC_SUBVOL_CREATE:
3266 return btrfs_ioctl_snap_create(file, argp, 1);
3267 case BTRFS_IOC_SNAP_DESTROY:
3268 return btrfs_ioctl_snap_destroy(file, argp);
3269 case BTRFS_IOC_SUBVOL_GETFLAGS:
3270 return btrfs_ioctl_subvol_getflags(file, argp);
3271 case BTRFS_IOC_SUBVOL_SETFLAGS:
3272 return btrfs_ioctl_subvol_setflags(file, argp);
3273 case BTRFS_IOC_DEFAULT_SUBVOL:
3274 return btrfs_ioctl_default_subvol(file, argp);
3275 case BTRFS_IOC_DEFRAG:
3276 return btrfs_ioctl_defrag(file, NULL);
3277 case BTRFS_IOC_DEFRAG_RANGE:
3278 return btrfs_ioctl_defrag(file, argp);
3279 case BTRFS_IOC_RESIZE:
3280 return btrfs_ioctl_resize(root, argp);
3281 case BTRFS_IOC_ADD_DEV:
3282 return btrfs_ioctl_add_dev(root, argp);
3283 case BTRFS_IOC_RM_DEV:
3284 return btrfs_ioctl_rm_dev(root, argp);
3285 case BTRFS_IOC_FS_INFO:
3286 return btrfs_ioctl_fs_info(root, argp);
3287 case BTRFS_IOC_DEV_INFO:
3288 return btrfs_ioctl_dev_info(root, argp);
3289 case BTRFS_IOC_BALANCE:
3290 return btrfs_ioctl_balance(root, NULL);
3291 case BTRFS_IOC_CLONE:
3292 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
3293 case BTRFS_IOC_CLONE_RANGE:
3294 return btrfs_ioctl_clone_range(file, argp);
3295 case BTRFS_IOC_TRANS_START:
3296 return btrfs_ioctl_trans_start(file);
3297 case BTRFS_IOC_TRANS_END:
3298 return btrfs_ioctl_trans_end(file);
3299 case BTRFS_IOC_TREE_SEARCH:
3300 return btrfs_ioctl_tree_search(file, argp);
3301 case BTRFS_IOC_INO_LOOKUP:
3302 return btrfs_ioctl_ino_lookup(file, argp);
3303 case BTRFS_IOC_INO_PATHS:
3304 return btrfs_ioctl_ino_to_path(root, argp);
3305 case BTRFS_IOC_LOGICAL_INO:
3306 return btrfs_ioctl_logical_to_ino(root, argp);
3307 case BTRFS_IOC_SPACE_INFO:
3308 return btrfs_ioctl_space_info(root, argp);
3309 case BTRFS_IOC_SYNC:
3310 btrfs_sync_fs(file->f_dentry->d_sb, 1);
3311 return 0;
3312 case BTRFS_IOC_START_SYNC:
3313 return btrfs_ioctl_start_sync(file, argp);
3314 case BTRFS_IOC_WAIT_SYNC:
3315 return btrfs_ioctl_wait_sync(file, argp);
3316 case BTRFS_IOC_SCRUB:
3317 return btrfs_ioctl_scrub(root, argp);
3318 case BTRFS_IOC_SCRUB_CANCEL:
3319 return btrfs_ioctl_scrub_cancel(root, argp);
3320 case BTRFS_IOC_SCRUB_PROGRESS:
3321 return btrfs_ioctl_scrub_progress(root, argp);
3322 case BTRFS_IOC_BALANCE_V2:
3323 return btrfs_ioctl_balance(root, argp);
3324 case BTRFS_IOC_BALANCE_CTL:
3325 return btrfs_ioctl_balance_ctl(root, arg);
3326 case BTRFS_IOC_BALANCE_PROGRESS:
3327 return btrfs_ioctl_balance_progress(root, argp);
3328 }
3329
3330 return -ENOTTY;
3331 }