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Btrfs: fix clone to deal with holes when NO_HOLES feature is enabled
[deliverable/linux.git] / fs / btrfs / ioctl.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/fsnotify.h>
25 #include <linux/pagemap.h>
26 #include <linux/highmem.h>
27 #include <linux/time.h>
28 #include <linux/init.h>
29 #include <linux/string.h>
30 #include <linux/backing-dev.h>
31 #include <linux/mount.h>
32 #include <linux/mpage.h>
33 #include <linux/namei.h>
34 #include <linux/swap.h>
35 #include <linux/writeback.h>
36 #include <linux/statfs.h>
37 #include <linux/compat.h>
38 #include <linux/bit_spinlock.h>
39 #include <linux/security.h>
40 #include <linux/xattr.h>
41 #include <linux/vmalloc.h>
42 #include <linux/slab.h>
43 #include <linux/blkdev.h>
44 #include <linux/uuid.h>
45 #include <linux/btrfs.h>
46 #include <linux/uaccess.h>
47 #include "ctree.h"
48 #include "disk-io.h"
49 #include "transaction.h"
50 #include "btrfs_inode.h"
51 #include "print-tree.h"
52 #include "volumes.h"
53 #include "locking.h"
54 #include "inode-map.h"
55 #include "backref.h"
56 #include "rcu-string.h"
57 #include "send.h"
58 #include "dev-replace.h"
59 #include "props.h"
60 #include "sysfs.h"
61 #include "qgroup.h"
62
63 #ifdef CONFIG_64BIT
64 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
65 * structures are incorrect, as the timespec structure from userspace
66 * is 4 bytes too small. We define these alternatives here to teach
67 * the kernel about the 32-bit struct packing.
68 */
69 struct btrfs_ioctl_timespec_32 {
70 __u64 sec;
71 __u32 nsec;
72 } __attribute__ ((__packed__));
73
74 struct btrfs_ioctl_received_subvol_args_32 {
75 char uuid[BTRFS_UUID_SIZE]; /* in */
76 __u64 stransid; /* in */
77 __u64 rtransid; /* out */
78 struct btrfs_ioctl_timespec_32 stime; /* in */
79 struct btrfs_ioctl_timespec_32 rtime; /* out */
80 __u64 flags; /* in */
81 __u64 reserved[16]; /* in */
82 } __attribute__ ((__packed__));
83
84 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
85 struct btrfs_ioctl_received_subvol_args_32)
86 #endif
87
88
89 static int btrfs_clone(struct inode *src, struct inode *inode,
90 u64 off, u64 olen, u64 olen_aligned, u64 destoff);
91
92 /* Mask out flags that are inappropriate for the given type of inode. */
93 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
94 {
95 if (S_ISDIR(mode))
96 return flags;
97 else if (S_ISREG(mode))
98 return flags & ~FS_DIRSYNC_FL;
99 else
100 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
101 }
102
103 /*
104 * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
105 */
106 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
107 {
108 unsigned int iflags = 0;
109
110 if (flags & BTRFS_INODE_SYNC)
111 iflags |= FS_SYNC_FL;
112 if (flags & BTRFS_INODE_IMMUTABLE)
113 iflags |= FS_IMMUTABLE_FL;
114 if (flags & BTRFS_INODE_APPEND)
115 iflags |= FS_APPEND_FL;
116 if (flags & BTRFS_INODE_NODUMP)
117 iflags |= FS_NODUMP_FL;
118 if (flags & BTRFS_INODE_NOATIME)
119 iflags |= FS_NOATIME_FL;
120 if (flags & BTRFS_INODE_DIRSYNC)
121 iflags |= FS_DIRSYNC_FL;
122 if (flags & BTRFS_INODE_NODATACOW)
123 iflags |= FS_NOCOW_FL;
124
125 if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS))
126 iflags |= FS_COMPR_FL;
127 else if (flags & BTRFS_INODE_NOCOMPRESS)
128 iflags |= FS_NOCOMP_FL;
129
130 return iflags;
131 }
132
133 /*
134 * Update inode->i_flags based on the btrfs internal flags.
135 */
136 void btrfs_update_iflags(struct inode *inode)
137 {
138 struct btrfs_inode *ip = BTRFS_I(inode);
139
140 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
141
142 if (ip->flags & BTRFS_INODE_SYNC)
143 inode->i_flags |= S_SYNC;
144 if (ip->flags & BTRFS_INODE_IMMUTABLE)
145 inode->i_flags |= S_IMMUTABLE;
146 if (ip->flags & BTRFS_INODE_APPEND)
147 inode->i_flags |= S_APPEND;
148 if (ip->flags & BTRFS_INODE_NOATIME)
149 inode->i_flags |= S_NOATIME;
150 if (ip->flags & BTRFS_INODE_DIRSYNC)
151 inode->i_flags |= S_DIRSYNC;
152 }
153
154 /*
155 * Inherit flags from the parent inode.
156 *
157 * Currently only the compression flags and the cow flags are inherited.
158 */
159 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
160 {
161 unsigned int flags;
162
163 if (!dir)
164 return;
165
166 flags = BTRFS_I(dir)->flags;
167
168 if (flags & BTRFS_INODE_NOCOMPRESS) {
169 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
170 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
171 } else if (flags & BTRFS_INODE_COMPRESS) {
172 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
173 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
174 }
175
176 if (flags & BTRFS_INODE_NODATACOW) {
177 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
178 if (S_ISREG(inode->i_mode))
179 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
180 }
181
182 btrfs_update_iflags(inode);
183 }
184
185 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
186 {
187 struct btrfs_inode *ip = BTRFS_I(file_inode(file));
188 unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
189
190 if (copy_to_user(arg, &flags, sizeof(flags)))
191 return -EFAULT;
192 return 0;
193 }
194
195 static int check_flags(unsigned int flags)
196 {
197 if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
198 FS_NOATIME_FL | FS_NODUMP_FL | \
199 FS_SYNC_FL | FS_DIRSYNC_FL | \
200 FS_NOCOMP_FL | FS_COMPR_FL |
201 FS_NOCOW_FL))
202 return -EOPNOTSUPP;
203
204 if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
205 return -EINVAL;
206
207 return 0;
208 }
209
210 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
211 {
212 struct inode *inode = file_inode(file);
213 struct btrfs_inode *ip = BTRFS_I(inode);
214 struct btrfs_root *root = ip->root;
215 struct btrfs_trans_handle *trans;
216 unsigned int flags, oldflags;
217 int ret;
218 u64 ip_oldflags;
219 unsigned int i_oldflags;
220 umode_t mode;
221
222 if (!inode_owner_or_capable(inode))
223 return -EPERM;
224
225 if (btrfs_root_readonly(root))
226 return -EROFS;
227
228 if (copy_from_user(&flags, arg, sizeof(flags)))
229 return -EFAULT;
230
231 ret = check_flags(flags);
232 if (ret)
233 return ret;
234
235 ret = mnt_want_write_file(file);
236 if (ret)
237 return ret;
238
239 mutex_lock(&inode->i_mutex);
240
241 ip_oldflags = ip->flags;
242 i_oldflags = inode->i_flags;
243 mode = inode->i_mode;
244
245 flags = btrfs_mask_flags(inode->i_mode, flags);
246 oldflags = btrfs_flags_to_ioctl(ip->flags);
247 if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
248 if (!capable(CAP_LINUX_IMMUTABLE)) {
249 ret = -EPERM;
250 goto out_unlock;
251 }
252 }
253
254 if (flags & FS_SYNC_FL)
255 ip->flags |= BTRFS_INODE_SYNC;
256 else
257 ip->flags &= ~BTRFS_INODE_SYNC;
258 if (flags & FS_IMMUTABLE_FL)
259 ip->flags |= BTRFS_INODE_IMMUTABLE;
260 else
261 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
262 if (flags & FS_APPEND_FL)
263 ip->flags |= BTRFS_INODE_APPEND;
264 else
265 ip->flags &= ~BTRFS_INODE_APPEND;
266 if (flags & FS_NODUMP_FL)
267 ip->flags |= BTRFS_INODE_NODUMP;
268 else
269 ip->flags &= ~BTRFS_INODE_NODUMP;
270 if (flags & FS_NOATIME_FL)
271 ip->flags |= BTRFS_INODE_NOATIME;
272 else
273 ip->flags &= ~BTRFS_INODE_NOATIME;
274 if (flags & FS_DIRSYNC_FL)
275 ip->flags |= BTRFS_INODE_DIRSYNC;
276 else
277 ip->flags &= ~BTRFS_INODE_DIRSYNC;
278 if (flags & FS_NOCOW_FL) {
279 if (S_ISREG(mode)) {
280 /*
281 * It's safe to turn csums off here, no extents exist.
282 * Otherwise we want the flag to reflect the real COW
283 * status of the file and will not set it.
284 */
285 if (inode->i_size == 0)
286 ip->flags |= BTRFS_INODE_NODATACOW
287 | BTRFS_INODE_NODATASUM;
288 } else {
289 ip->flags |= BTRFS_INODE_NODATACOW;
290 }
291 } else {
292 /*
293 * Revert back under same assuptions as above
294 */
295 if (S_ISREG(mode)) {
296 if (inode->i_size == 0)
297 ip->flags &= ~(BTRFS_INODE_NODATACOW
298 | BTRFS_INODE_NODATASUM);
299 } else {
300 ip->flags &= ~BTRFS_INODE_NODATACOW;
301 }
302 }
303
304 /*
305 * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
306 * flag may be changed automatically if compression code won't make
307 * things smaller.
308 */
309 if (flags & FS_NOCOMP_FL) {
310 ip->flags &= ~BTRFS_INODE_COMPRESS;
311 ip->flags |= BTRFS_INODE_NOCOMPRESS;
312
313 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
314 if (ret && ret != -ENODATA)
315 goto out_drop;
316 } else if (flags & FS_COMPR_FL) {
317 const char *comp;
318
319 ip->flags |= BTRFS_INODE_COMPRESS;
320 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
321
322 if (root->fs_info->compress_type == BTRFS_COMPRESS_LZO)
323 comp = "lzo";
324 else
325 comp = "zlib";
326 ret = btrfs_set_prop(inode, "btrfs.compression",
327 comp, strlen(comp), 0);
328 if (ret)
329 goto out_drop;
330
331 } else {
332 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
333 }
334
335 trans = btrfs_start_transaction(root, 1);
336 if (IS_ERR(trans)) {
337 ret = PTR_ERR(trans);
338 goto out_drop;
339 }
340
341 btrfs_update_iflags(inode);
342 inode_inc_iversion(inode);
343 inode->i_ctime = CURRENT_TIME;
344 ret = btrfs_update_inode(trans, root, inode);
345
346 btrfs_end_transaction(trans, root);
347 out_drop:
348 if (ret) {
349 ip->flags = ip_oldflags;
350 inode->i_flags = i_oldflags;
351 }
352
353 out_unlock:
354 mutex_unlock(&inode->i_mutex);
355 mnt_drop_write_file(file);
356 return ret;
357 }
358
359 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
360 {
361 struct inode *inode = file_inode(file);
362
363 return put_user(inode->i_generation, arg);
364 }
365
366 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
367 {
368 struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
369 struct btrfs_device *device;
370 struct request_queue *q;
371 struct fstrim_range range;
372 u64 minlen = ULLONG_MAX;
373 u64 num_devices = 0;
374 u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
375 int ret;
376
377 if (!capable(CAP_SYS_ADMIN))
378 return -EPERM;
379
380 rcu_read_lock();
381 list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
382 dev_list) {
383 if (!device->bdev)
384 continue;
385 q = bdev_get_queue(device->bdev);
386 if (blk_queue_discard(q)) {
387 num_devices++;
388 minlen = min((u64)q->limits.discard_granularity,
389 minlen);
390 }
391 }
392 rcu_read_unlock();
393
394 if (!num_devices)
395 return -EOPNOTSUPP;
396 if (copy_from_user(&range, arg, sizeof(range)))
397 return -EFAULT;
398 if (range.start > total_bytes ||
399 range.len < fs_info->sb->s_blocksize)
400 return -EINVAL;
401
402 range.len = min(range.len, total_bytes - range.start);
403 range.minlen = max(range.minlen, minlen);
404 ret = btrfs_trim_fs(fs_info->tree_root, &range);
405 if (ret < 0)
406 return ret;
407
408 if (copy_to_user(arg, &range, sizeof(range)))
409 return -EFAULT;
410
411 return 0;
412 }
413
414 int btrfs_is_empty_uuid(u8 *uuid)
415 {
416 int i;
417
418 for (i = 0; i < BTRFS_UUID_SIZE; i++) {
419 if (uuid[i])
420 return 0;
421 }
422 return 1;
423 }
424
425 static noinline int create_subvol(struct inode *dir,
426 struct dentry *dentry,
427 char *name, int namelen,
428 u64 *async_transid,
429 struct btrfs_qgroup_inherit *inherit)
430 {
431 struct btrfs_trans_handle *trans;
432 struct btrfs_key key;
433 struct btrfs_root_item root_item;
434 struct btrfs_inode_item *inode_item;
435 struct extent_buffer *leaf;
436 struct btrfs_root *root = BTRFS_I(dir)->root;
437 struct btrfs_root *new_root;
438 struct btrfs_block_rsv block_rsv;
439 struct timespec cur_time = CURRENT_TIME;
440 struct inode *inode;
441 int ret;
442 int err;
443 u64 objectid;
444 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
445 u64 index = 0;
446 u64 qgroup_reserved;
447 uuid_le new_uuid;
448
449 ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
450 if (ret)
451 return ret;
452
453 btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
454 /*
455 * The same as the snapshot creation, please see the comment
456 * of create_snapshot().
457 */
458 ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
459 8, &qgroup_reserved, false);
460 if (ret)
461 return ret;
462
463 trans = btrfs_start_transaction(root, 0);
464 if (IS_ERR(trans)) {
465 ret = PTR_ERR(trans);
466 btrfs_subvolume_release_metadata(root, &block_rsv,
467 qgroup_reserved);
468 return ret;
469 }
470 trans->block_rsv = &block_rsv;
471 trans->bytes_reserved = block_rsv.size;
472
473 ret = btrfs_qgroup_inherit(trans, root->fs_info, 0, objectid, inherit);
474 if (ret)
475 goto fail;
476
477 leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
478 0, objectid, NULL, 0, 0, 0);
479 if (IS_ERR(leaf)) {
480 ret = PTR_ERR(leaf);
481 goto fail;
482 }
483
484 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
485 btrfs_set_header_bytenr(leaf, leaf->start);
486 btrfs_set_header_generation(leaf, trans->transid);
487 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
488 btrfs_set_header_owner(leaf, objectid);
489
490 write_extent_buffer(leaf, root->fs_info->fsid, btrfs_header_fsid(),
491 BTRFS_FSID_SIZE);
492 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
493 btrfs_header_chunk_tree_uuid(leaf),
494 BTRFS_UUID_SIZE);
495 btrfs_mark_buffer_dirty(leaf);
496
497 memset(&root_item, 0, sizeof(root_item));
498
499 inode_item = &root_item.inode;
500 btrfs_set_stack_inode_generation(inode_item, 1);
501 btrfs_set_stack_inode_size(inode_item, 3);
502 btrfs_set_stack_inode_nlink(inode_item, 1);
503 btrfs_set_stack_inode_nbytes(inode_item, root->leafsize);
504 btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
505
506 btrfs_set_root_flags(&root_item, 0);
507 btrfs_set_root_limit(&root_item, 0);
508 btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
509
510 btrfs_set_root_bytenr(&root_item, leaf->start);
511 btrfs_set_root_generation(&root_item, trans->transid);
512 btrfs_set_root_level(&root_item, 0);
513 btrfs_set_root_refs(&root_item, 1);
514 btrfs_set_root_used(&root_item, leaf->len);
515 btrfs_set_root_last_snapshot(&root_item, 0);
516
517 btrfs_set_root_generation_v2(&root_item,
518 btrfs_root_generation(&root_item));
519 uuid_le_gen(&new_uuid);
520 memcpy(root_item.uuid, new_uuid.b, BTRFS_UUID_SIZE);
521 btrfs_set_stack_timespec_sec(&root_item.otime, cur_time.tv_sec);
522 btrfs_set_stack_timespec_nsec(&root_item.otime, cur_time.tv_nsec);
523 root_item.ctime = root_item.otime;
524 btrfs_set_root_ctransid(&root_item, trans->transid);
525 btrfs_set_root_otransid(&root_item, trans->transid);
526
527 btrfs_tree_unlock(leaf);
528 free_extent_buffer(leaf);
529 leaf = NULL;
530
531 btrfs_set_root_dirid(&root_item, new_dirid);
532
533 key.objectid = objectid;
534 key.offset = 0;
535 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
536 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
537 &root_item);
538 if (ret)
539 goto fail;
540
541 key.offset = (u64)-1;
542 new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
543 if (IS_ERR(new_root)) {
544 btrfs_abort_transaction(trans, root, PTR_ERR(new_root));
545 ret = PTR_ERR(new_root);
546 goto fail;
547 }
548
549 btrfs_record_root_in_trans(trans, new_root);
550
551 ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
552 if (ret) {
553 /* We potentially lose an unused inode item here */
554 btrfs_abort_transaction(trans, root, ret);
555 goto fail;
556 }
557
558 /*
559 * insert the directory item
560 */
561 ret = btrfs_set_inode_index(dir, &index);
562 if (ret) {
563 btrfs_abort_transaction(trans, root, ret);
564 goto fail;
565 }
566
567 ret = btrfs_insert_dir_item(trans, root,
568 name, namelen, dir, &key,
569 BTRFS_FT_DIR, index);
570 if (ret) {
571 btrfs_abort_transaction(trans, root, ret);
572 goto fail;
573 }
574
575 btrfs_i_size_write(dir, dir->i_size + namelen * 2);
576 ret = btrfs_update_inode(trans, root, dir);
577 BUG_ON(ret);
578
579 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
580 objectid, root->root_key.objectid,
581 btrfs_ino(dir), index, name, namelen);
582 BUG_ON(ret);
583
584 ret = btrfs_uuid_tree_add(trans, root->fs_info->uuid_root,
585 root_item.uuid, BTRFS_UUID_KEY_SUBVOL,
586 objectid);
587 if (ret)
588 btrfs_abort_transaction(trans, root, ret);
589
590 fail:
591 trans->block_rsv = NULL;
592 trans->bytes_reserved = 0;
593 btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);
594
595 if (async_transid) {
596 *async_transid = trans->transid;
597 err = btrfs_commit_transaction_async(trans, root, 1);
598 if (err)
599 err = btrfs_commit_transaction(trans, root);
600 } else {
601 err = btrfs_commit_transaction(trans, root);
602 }
603 if (err && !ret)
604 ret = err;
605
606 if (!ret) {
607 inode = btrfs_lookup_dentry(dir, dentry);
608 if (IS_ERR(inode))
609 return PTR_ERR(inode);
610 d_instantiate(dentry, inode);
611 }
612 return ret;
613 }
614
615 static void btrfs_wait_nocow_write(struct btrfs_root *root)
616 {
617 s64 writers;
618 DEFINE_WAIT(wait);
619
620 do {
621 prepare_to_wait(&root->subv_writers->wait, &wait,
622 TASK_UNINTERRUPTIBLE);
623
624 writers = percpu_counter_sum(&root->subv_writers->counter);
625 if (writers)
626 schedule();
627
628 finish_wait(&root->subv_writers->wait, &wait);
629 } while (writers);
630 }
631
632 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
633 struct dentry *dentry, char *name, int namelen,
634 u64 *async_transid, bool readonly,
635 struct btrfs_qgroup_inherit *inherit)
636 {
637 struct inode *inode;
638 struct btrfs_pending_snapshot *pending_snapshot;
639 struct btrfs_trans_handle *trans;
640 int ret;
641
642 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
643 return -EINVAL;
644
645 atomic_inc(&root->will_be_snapshoted);
646 smp_mb__after_atomic_inc();
647 btrfs_wait_nocow_write(root);
648
649 ret = btrfs_start_delalloc_inodes(root, 0);
650 if (ret)
651 goto out;
652
653 btrfs_wait_ordered_extents(root, -1);
654
655 pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
656 if (!pending_snapshot) {
657 ret = -ENOMEM;
658 goto out;
659 }
660
661 btrfs_init_block_rsv(&pending_snapshot->block_rsv,
662 BTRFS_BLOCK_RSV_TEMP);
663 /*
664 * 1 - parent dir inode
665 * 2 - dir entries
666 * 1 - root item
667 * 2 - root ref/backref
668 * 1 - root of snapshot
669 * 1 - UUID item
670 */
671 ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
672 &pending_snapshot->block_rsv, 8,
673 &pending_snapshot->qgroup_reserved,
674 false);
675 if (ret)
676 goto free;
677
678 pending_snapshot->dentry = dentry;
679 pending_snapshot->root = root;
680 pending_snapshot->readonly = readonly;
681 pending_snapshot->dir = dir;
682 pending_snapshot->inherit = inherit;
683
684 trans = btrfs_start_transaction(root, 0);
685 if (IS_ERR(trans)) {
686 ret = PTR_ERR(trans);
687 goto fail;
688 }
689
690 spin_lock(&root->fs_info->trans_lock);
691 list_add(&pending_snapshot->list,
692 &trans->transaction->pending_snapshots);
693 spin_unlock(&root->fs_info->trans_lock);
694 if (async_transid) {
695 *async_transid = trans->transid;
696 ret = btrfs_commit_transaction_async(trans,
697 root->fs_info->extent_root, 1);
698 if (ret)
699 ret = btrfs_commit_transaction(trans, root);
700 } else {
701 ret = btrfs_commit_transaction(trans,
702 root->fs_info->extent_root);
703 }
704 if (ret)
705 goto fail;
706
707 ret = pending_snapshot->error;
708 if (ret)
709 goto fail;
710
711 ret = btrfs_orphan_cleanup(pending_snapshot->snap);
712 if (ret)
713 goto fail;
714
715 /*
716 * If orphan cleanup did remove any orphans, it means the tree was
717 * modified and therefore the commit root is not the same as the
718 * current root anymore. This is a problem, because send uses the
719 * commit root and therefore can see inode items that don't exist
720 * in the current root anymore, and for example make calls to
721 * btrfs_iget, which will do tree lookups based on the current root
722 * and not on the commit root. Those lookups will fail, returning a
723 * -ESTALE error, and making send fail with that error. So make sure
724 * a send does not see any orphans we have just removed, and that it
725 * will see the same inodes regardless of whether a transaction
726 * commit happened before it started (meaning that the commit root
727 * will be the same as the current root) or not.
728 */
729 if (readonly && pending_snapshot->snap->node !=
730 pending_snapshot->snap->commit_root) {
731 trans = btrfs_join_transaction(pending_snapshot->snap);
732 if (IS_ERR(trans) && PTR_ERR(trans) != -ENOENT) {
733 ret = PTR_ERR(trans);
734 goto fail;
735 }
736 if (!IS_ERR(trans)) {
737 ret = btrfs_commit_transaction(trans,
738 pending_snapshot->snap);
739 if (ret)
740 goto fail;
741 }
742 }
743
744 inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
745 if (IS_ERR(inode)) {
746 ret = PTR_ERR(inode);
747 goto fail;
748 }
749
750 d_instantiate(dentry, inode);
751 ret = 0;
752 fail:
753 btrfs_subvolume_release_metadata(BTRFS_I(dir)->root,
754 &pending_snapshot->block_rsv,
755 pending_snapshot->qgroup_reserved);
756 free:
757 kfree(pending_snapshot);
758 out:
759 atomic_dec(&root->will_be_snapshoted);
760 return ret;
761 }
762
763 /* copy of check_sticky in fs/namei.c()
764 * It's inline, so penalty for filesystems that don't use sticky bit is
765 * minimal.
766 */
767 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode)
768 {
769 kuid_t fsuid = current_fsuid();
770
771 if (!(dir->i_mode & S_ISVTX))
772 return 0;
773 if (uid_eq(inode->i_uid, fsuid))
774 return 0;
775 if (uid_eq(dir->i_uid, fsuid))
776 return 0;
777 return !capable(CAP_FOWNER);
778 }
779
780 /* copy of may_delete in fs/namei.c()
781 * Check whether we can remove a link victim from directory dir, check
782 * whether the type of victim is right.
783 * 1. We can't do it if dir is read-only (done in permission())
784 * 2. We should have write and exec permissions on dir
785 * 3. We can't remove anything from append-only dir
786 * 4. We can't do anything with immutable dir (done in permission())
787 * 5. If the sticky bit on dir is set we should either
788 * a. be owner of dir, or
789 * b. be owner of victim, or
790 * c. have CAP_FOWNER capability
791 * 6. If the victim is append-only or immutable we can't do antyhing with
792 * links pointing to it.
793 * 7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
794 * 8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
795 * 9. We can't remove a root or mountpoint.
796 * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
797 * nfs_async_unlink().
798 */
799
800 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
801 {
802 int error;
803
804 if (!victim->d_inode)
805 return -ENOENT;
806
807 BUG_ON(victim->d_parent->d_inode != dir);
808 audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
809
810 error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
811 if (error)
812 return error;
813 if (IS_APPEND(dir))
814 return -EPERM;
815 if (btrfs_check_sticky(dir, victim->d_inode)||
816 IS_APPEND(victim->d_inode)||
817 IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
818 return -EPERM;
819 if (isdir) {
820 if (!S_ISDIR(victim->d_inode->i_mode))
821 return -ENOTDIR;
822 if (IS_ROOT(victim))
823 return -EBUSY;
824 } else if (S_ISDIR(victim->d_inode->i_mode))
825 return -EISDIR;
826 if (IS_DEADDIR(dir))
827 return -ENOENT;
828 if (victim->d_flags & DCACHE_NFSFS_RENAMED)
829 return -EBUSY;
830 return 0;
831 }
832
833 /* copy of may_create in fs/namei.c() */
834 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
835 {
836 if (child->d_inode)
837 return -EEXIST;
838 if (IS_DEADDIR(dir))
839 return -ENOENT;
840 return inode_permission(dir, MAY_WRITE | MAY_EXEC);
841 }
842
843 /*
844 * Create a new subvolume below @parent. This is largely modeled after
845 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
846 * inside this filesystem so it's quite a bit simpler.
847 */
848 static noinline int btrfs_mksubvol(struct path *parent,
849 char *name, int namelen,
850 struct btrfs_root *snap_src,
851 u64 *async_transid, bool readonly,
852 struct btrfs_qgroup_inherit *inherit)
853 {
854 struct inode *dir = parent->dentry->d_inode;
855 struct dentry *dentry;
856 int error;
857
858 error = mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT);
859 if (error == -EINTR)
860 return error;
861
862 dentry = lookup_one_len(name, parent->dentry, namelen);
863 error = PTR_ERR(dentry);
864 if (IS_ERR(dentry))
865 goto out_unlock;
866
867 error = -EEXIST;
868 if (dentry->d_inode)
869 goto out_dput;
870
871 error = btrfs_may_create(dir, dentry);
872 if (error)
873 goto out_dput;
874
875 /*
876 * even if this name doesn't exist, we may get hash collisions.
877 * check for them now when we can safely fail
878 */
879 error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
880 dir->i_ino, name,
881 namelen);
882 if (error)
883 goto out_dput;
884
885 down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
886
887 if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
888 goto out_up_read;
889
890 if (snap_src) {
891 error = create_snapshot(snap_src, dir, dentry, name, namelen,
892 async_transid, readonly, inherit);
893 } else {
894 error = create_subvol(dir, dentry, name, namelen,
895 async_transid, inherit);
896 }
897 if (!error)
898 fsnotify_mkdir(dir, dentry);
899 out_up_read:
900 up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
901 out_dput:
902 dput(dentry);
903 out_unlock:
904 mutex_unlock(&dir->i_mutex);
905 return error;
906 }
907
908 /*
909 * When we're defragging a range, we don't want to kick it off again
910 * if it is really just waiting for delalloc to send it down.
911 * If we find a nice big extent or delalloc range for the bytes in the
912 * file you want to defrag, we return 0 to let you know to skip this
913 * part of the file
914 */
915 static int check_defrag_in_cache(struct inode *inode, u64 offset, int thresh)
916 {
917 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
918 struct extent_map *em = NULL;
919 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
920 u64 end;
921
922 read_lock(&em_tree->lock);
923 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
924 read_unlock(&em_tree->lock);
925
926 if (em) {
927 end = extent_map_end(em);
928 free_extent_map(em);
929 if (end - offset > thresh)
930 return 0;
931 }
932 /* if we already have a nice delalloc here, just stop */
933 thresh /= 2;
934 end = count_range_bits(io_tree, &offset, offset + thresh,
935 thresh, EXTENT_DELALLOC, 1);
936 if (end >= thresh)
937 return 0;
938 return 1;
939 }
940
941 /*
942 * helper function to walk through a file and find extents
943 * newer than a specific transid, and smaller than thresh.
944 *
945 * This is used by the defragging code to find new and small
946 * extents
947 */
948 static int find_new_extents(struct btrfs_root *root,
949 struct inode *inode, u64 newer_than,
950 u64 *off, int thresh)
951 {
952 struct btrfs_path *path;
953 struct btrfs_key min_key;
954 struct extent_buffer *leaf;
955 struct btrfs_file_extent_item *extent;
956 int type;
957 int ret;
958 u64 ino = btrfs_ino(inode);
959
960 path = btrfs_alloc_path();
961 if (!path)
962 return -ENOMEM;
963
964 min_key.objectid = ino;
965 min_key.type = BTRFS_EXTENT_DATA_KEY;
966 min_key.offset = *off;
967
968 while (1) {
969 path->keep_locks = 1;
970 ret = btrfs_search_forward(root, &min_key, path, newer_than);
971 if (ret != 0)
972 goto none;
973 path->keep_locks = 0;
974 btrfs_unlock_up_safe(path, 1);
975 process_slot:
976 if (min_key.objectid != ino)
977 goto none;
978 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
979 goto none;
980
981 leaf = path->nodes[0];
982 extent = btrfs_item_ptr(leaf, path->slots[0],
983 struct btrfs_file_extent_item);
984
985 type = btrfs_file_extent_type(leaf, extent);
986 if (type == BTRFS_FILE_EXTENT_REG &&
987 btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
988 check_defrag_in_cache(inode, min_key.offset, thresh)) {
989 *off = min_key.offset;
990 btrfs_free_path(path);
991 return 0;
992 }
993
994 path->slots[0]++;
995 if (path->slots[0] < btrfs_header_nritems(leaf)) {
996 btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
997 goto process_slot;
998 }
999
1000 if (min_key.offset == (u64)-1)
1001 goto none;
1002
1003 min_key.offset++;
1004 btrfs_release_path(path);
1005 }
1006 none:
1007 btrfs_free_path(path);
1008 return -ENOENT;
1009 }
1010
1011 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
1012 {
1013 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1014 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1015 struct extent_map *em;
1016 u64 len = PAGE_CACHE_SIZE;
1017
1018 /*
1019 * hopefully we have this extent in the tree already, try without
1020 * the full extent lock
1021 */
1022 read_lock(&em_tree->lock);
1023 em = lookup_extent_mapping(em_tree, start, len);
1024 read_unlock(&em_tree->lock);
1025
1026 if (!em) {
1027 struct extent_state *cached = NULL;
1028 u64 end = start + len - 1;
1029
1030 /* get the big lock and read metadata off disk */
1031 lock_extent_bits(io_tree, start, end, 0, &cached);
1032 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
1033 unlock_extent_cached(io_tree, start, end, &cached, GFP_NOFS);
1034
1035 if (IS_ERR(em))
1036 return NULL;
1037 }
1038
1039 return em;
1040 }
1041
1042 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1043 {
1044 struct extent_map *next;
1045 bool ret = true;
1046
1047 /* this is the last extent */
1048 if (em->start + em->len >= i_size_read(inode))
1049 return false;
1050
1051 next = defrag_lookup_extent(inode, em->start + em->len);
1052 if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE ||
1053 (em->block_start + em->block_len == next->block_start))
1054 ret = false;
1055
1056 free_extent_map(next);
1057 return ret;
1058 }
1059
1060 static int should_defrag_range(struct inode *inode, u64 start, int thresh,
1061 u64 *last_len, u64 *skip, u64 *defrag_end,
1062 int compress)
1063 {
1064 struct extent_map *em;
1065 int ret = 1;
1066 bool next_mergeable = true;
1067
1068 /*
1069 * make sure that once we start defragging an extent, we keep on
1070 * defragging it
1071 */
1072 if (start < *defrag_end)
1073 return 1;
1074
1075 *skip = 0;
1076
1077 em = defrag_lookup_extent(inode, start);
1078 if (!em)
1079 return 0;
1080
1081 /* this will cover holes, and inline extents */
1082 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1083 ret = 0;
1084 goto out;
1085 }
1086
1087 next_mergeable = defrag_check_next_extent(inode, em);
1088
1089 /*
1090 * we hit a real extent, if it is big or the next extent is not a
1091 * real extent, don't bother defragging it
1092 */
1093 if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1094 (em->len >= thresh || !next_mergeable))
1095 ret = 0;
1096 out:
1097 /*
1098 * last_len ends up being a counter of how many bytes we've defragged.
1099 * every time we choose not to defrag an extent, we reset *last_len
1100 * so that the next tiny extent will force a defrag.
1101 *
1102 * The end result of this is that tiny extents before a single big
1103 * extent will force at least part of that big extent to be defragged.
1104 */
1105 if (ret) {
1106 *defrag_end = extent_map_end(em);
1107 } else {
1108 *last_len = 0;
1109 *skip = extent_map_end(em);
1110 *defrag_end = 0;
1111 }
1112
1113 free_extent_map(em);
1114 return ret;
1115 }
1116
1117 /*
1118 * it doesn't do much good to defrag one or two pages
1119 * at a time. This pulls in a nice chunk of pages
1120 * to COW and defrag.
1121 *
1122 * It also makes sure the delalloc code has enough
1123 * dirty data to avoid making new small extents as part
1124 * of the defrag
1125 *
1126 * It's a good idea to start RA on this range
1127 * before calling this.
1128 */
1129 static int cluster_pages_for_defrag(struct inode *inode,
1130 struct page **pages,
1131 unsigned long start_index,
1132 unsigned long num_pages)
1133 {
1134 unsigned long file_end;
1135 u64 isize = i_size_read(inode);
1136 u64 page_start;
1137 u64 page_end;
1138 u64 page_cnt;
1139 int ret;
1140 int i;
1141 int i_done;
1142 struct btrfs_ordered_extent *ordered;
1143 struct extent_state *cached_state = NULL;
1144 struct extent_io_tree *tree;
1145 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1146
1147 file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
1148 if (!isize || start_index > file_end)
1149 return 0;
1150
1151 page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1152
1153 ret = btrfs_delalloc_reserve_space(inode,
1154 page_cnt << PAGE_CACHE_SHIFT);
1155 if (ret)
1156 return ret;
1157 i_done = 0;
1158 tree = &BTRFS_I(inode)->io_tree;
1159
1160 /* step one, lock all the pages */
1161 for (i = 0; i < page_cnt; i++) {
1162 struct page *page;
1163 again:
1164 page = find_or_create_page(inode->i_mapping,
1165 start_index + i, mask);
1166 if (!page)
1167 break;
1168
1169 page_start = page_offset(page);
1170 page_end = page_start + PAGE_CACHE_SIZE - 1;
1171 while (1) {
1172 lock_extent_bits(tree, page_start, page_end,
1173 0, &cached_state);
1174 ordered = btrfs_lookup_ordered_extent(inode,
1175 page_start);
1176 unlock_extent_cached(tree, page_start, page_end,
1177 &cached_state, GFP_NOFS);
1178 if (!ordered)
1179 break;
1180
1181 unlock_page(page);
1182 btrfs_start_ordered_extent(inode, ordered, 1);
1183 btrfs_put_ordered_extent(ordered);
1184 lock_page(page);
1185 /*
1186 * we unlocked the page above, so we need check if
1187 * it was released or not.
1188 */
1189 if (page->mapping != inode->i_mapping) {
1190 unlock_page(page);
1191 page_cache_release(page);
1192 goto again;
1193 }
1194 }
1195
1196 if (!PageUptodate(page)) {
1197 btrfs_readpage(NULL, page);
1198 lock_page(page);
1199 if (!PageUptodate(page)) {
1200 unlock_page(page);
1201 page_cache_release(page);
1202 ret = -EIO;
1203 break;
1204 }
1205 }
1206
1207 if (page->mapping != inode->i_mapping) {
1208 unlock_page(page);
1209 page_cache_release(page);
1210 goto again;
1211 }
1212
1213 pages[i] = page;
1214 i_done++;
1215 }
1216 if (!i_done || ret)
1217 goto out;
1218
1219 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1220 goto out;
1221
1222 /*
1223 * so now we have a nice long stream of locked
1224 * and up to date pages, lets wait on them
1225 */
1226 for (i = 0; i < i_done; i++)
1227 wait_on_page_writeback(pages[i]);
1228
1229 page_start = page_offset(pages[0]);
1230 page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
1231
1232 lock_extent_bits(&BTRFS_I(inode)->io_tree,
1233 page_start, page_end - 1, 0, &cached_state);
1234 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1235 page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1236 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1237 &cached_state, GFP_NOFS);
1238
1239 if (i_done != page_cnt) {
1240 spin_lock(&BTRFS_I(inode)->lock);
1241 BTRFS_I(inode)->outstanding_extents++;
1242 spin_unlock(&BTRFS_I(inode)->lock);
1243 btrfs_delalloc_release_space(inode,
1244 (page_cnt - i_done) << PAGE_CACHE_SHIFT);
1245 }
1246
1247
1248 set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1249 &cached_state, GFP_NOFS);
1250
1251 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1252 page_start, page_end - 1, &cached_state,
1253 GFP_NOFS);
1254
1255 for (i = 0; i < i_done; i++) {
1256 clear_page_dirty_for_io(pages[i]);
1257 ClearPageChecked(pages[i]);
1258 set_page_extent_mapped(pages[i]);
1259 set_page_dirty(pages[i]);
1260 unlock_page(pages[i]);
1261 page_cache_release(pages[i]);
1262 }
1263 return i_done;
1264 out:
1265 for (i = 0; i < i_done; i++) {
1266 unlock_page(pages[i]);
1267 page_cache_release(pages[i]);
1268 }
1269 btrfs_delalloc_release_space(inode, page_cnt << PAGE_CACHE_SHIFT);
1270 return ret;
1271
1272 }
1273
1274 int btrfs_defrag_file(struct inode *inode, struct file *file,
1275 struct btrfs_ioctl_defrag_range_args *range,
1276 u64 newer_than, unsigned long max_to_defrag)
1277 {
1278 struct btrfs_root *root = BTRFS_I(inode)->root;
1279 struct file_ra_state *ra = NULL;
1280 unsigned long last_index;
1281 u64 isize = i_size_read(inode);
1282 u64 last_len = 0;
1283 u64 skip = 0;
1284 u64 defrag_end = 0;
1285 u64 newer_off = range->start;
1286 unsigned long i;
1287 unsigned long ra_index = 0;
1288 int ret;
1289 int defrag_count = 0;
1290 int compress_type = BTRFS_COMPRESS_ZLIB;
1291 int extent_thresh = range->extent_thresh;
1292 unsigned long max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT;
1293 unsigned long cluster = max_cluster;
1294 u64 new_align = ~((u64)128 * 1024 - 1);
1295 struct page **pages = NULL;
1296
1297 if (isize == 0)
1298 return 0;
1299
1300 if (range->start >= isize)
1301 return -EINVAL;
1302
1303 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1304 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1305 return -EINVAL;
1306 if (range->compress_type)
1307 compress_type = range->compress_type;
1308 }
1309
1310 if (extent_thresh == 0)
1311 extent_thresh = 256 * 1024;
1312
1313 /*
1314 * if we were not given a file, allocate a readahead
1315 * context
1316 */
1317 if (!file) {
1318 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1319 if (!ra)
1320 return -ENOMEM;
1321 file_ra_state_init(ra, inode->i_mapping);
1322 } else {
1323 ra = &file->f_ra;
1324 }
1325
1326 pages = kmalloc_array(max_cluster, sizeof(struct page *),
1327 GFP_NOFS);
1328 if (!pages) {
1329 ret = -ENOMEM;
1330 goto out_ra;
1331 }
1332
1333 /* find the last page to defrag */
1334 if (range->start + range->len > range->start) {
1335 last_index = min_t(u64, isize - 1,
1336 range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
1337 } else {
1338 last_index = (isize - 1) >> PAGE_CACHE_SHIFT;
1339 }
1340
1341 if (newer_than) {
1342 ret = find_new_extents(root, inode, newer_than,
1343 &newer_off, 64 * 1024);
1344 if (!ret) {
1345 range->start = newer_off;
1346 /*
1347 * we always align our defrag to help keep
1348 * the extents in the file evenly spaced
1349 */
1350 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1351 } else
1352 goto out_ra;
1353 } else {
1354 i = range->start >> PAGE_CACHE_SHIFT;
1355 }
1356 if (!max_to_defrag)
1357 max_to_defrag = last_index + 1;
1358
1359 /*
1360 * make writeback starts from i, so the defrag range can be
1361 * written sequentially.
1362 */
1363 if (i < inode->i_mapping->writeback_index)
1364 inode->i_mapping->writeback_index = i;
1365
1366 while (i <= last_index && defrag_count < max_to_defrag &&
1367 (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1368 PAGE_CACHE_SHIFT)) {
1369 /*
1370 * make sure we stop running if someone unmounts
1371 * the FS
1372 */
1373 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1374 break;
1375
1376 if (btrfs_defrag_cancelled(root->fs_info)) {
1377 printk(KERN_DEBUG "BTRFS: defrag_file cancelled\n");
1378 ret = -EAGAIN;
1379 break;
1380 }
1381
1382 if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
1383 extent_thresh, &last_len, &skip,
1384 &defrag_end, range->flags &
1385 BTRFS_DEFRAG_RANGE_COMPRESS)) {
1386 unsigned long next;
1387 /*
1388 * the should_defrag function tells us how much to skip
1389 * bump our counter by the suggested amount
1390 */
1391 next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1392 i = max(i + 1, next);
1393 continue;
1394 }
1395
1396 if (!newer_than) {
1397 cluster = (PAGE_CACHE_ALIGN(defrag_end) >>
1398 PAGE_CACHE_SHIFT) - i;
1399 cluster = min(cluster, max_cluster);
1400 } else {
1401 cluster = max_cluster;
1402 }
1403
1404 if (i + cluster > ra_index) {
1405 ra_index = max(i, ra_index);
1406 btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1407 cluster);
1408 ra_index += max_cluster;
1409 }
1410
1411 mutex_lock(&inode->i_mutex);
1412 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1413 BTRFS_I(inode)->force_compress = compress_type;
1414 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1415 if (ret < 0) {
1416 mutex_unlock(&inode->i_mutex);
1417 goto out_ra;
1418 }
1419
1420 defrag_count += ret;
1421 balance_dirty_pages_ratelimited(inode->i_mapping);
1422 mutex_unlock(&inode->i_mutex);
1423
1424 if (newer_than) {
1425 if (newer_off == (u64)-1)
1426 break;
1427
1428 if (ret > 0)
1429 i += ret;
1430
1431 newer_off = max(newer_off + 1,
1432 (u64)i << PAGE_CACHE_SHIFT);
1433
1434 ret = find_new_extents(root, inode,
1435 newer_than, &newer_off,
1436 64 * 1024);
1437 if (!ret) {
1438 range->start = newer_off;
1439 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1440 } else {
1441 break;
1442 }
1443 } else {
1444 if (ret > 0) {
1445 i += ret;
1446 last_len += ret << PAGE_CACHE_SHIFT;
1447 } else {
1448 i++;
1449 last_len = 0;
1450 }
1451 }
1452 }
1453
1454 if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1455 filemap_flush(inode->i_mapping);
1456 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1457 &BTRFS_I(inode)->runtime_flags))
1458 filemap_flush(inode->i_mapping);
1459 }
1460
1461 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1462 /* the filemap_flush will queue IO into the worker threads, but
1463 * we have to make sure the IO is actually started and that
1464 * ordered extents get created before we return
1465 */
1466 atomic_inc(&root->fs_info->async_submit_draining);
1467 while (atomic_read(&root->fs_info->nr_async_submits) ||
1468 atomic_read(&root->fs_info->async_delalloc_pages)) {
1469 wait_event(root->fs_info->async_submit_wait,
1470 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1471 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1472 }
1473 atomic_dec(&root->fs_info->async_submit_draining);
1474 }
1475
1476 if (range->compress_type == BTRFS_COMPRESS_LZO) {
1477 btrfs_set_fs_incompat(root->fs_info, COMPRESS_LZO);
1478 }
1479
1480 ret = defrag_count;
1481
1482 out_ra:
1483 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1484 mutex_lock(&inode->i_mutex);
1485 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1486 mutex_unlock(&inode->i_mutex);
1487 }
1488 if (!file)
1489 kfree(ra);
1490 kfree(pages);
1491 return ret;
1492 }
1493
1494 static noinline int btrfs_ioctl_resize(struct file *file,
1495 void __user *arg)
1496 {
1497 u64 new_size;
1498 u64 old_size;
1499 u64 devid = 1;
1500 struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
1501 struct btrfs_ioctl_vol_args *vol_args;
1502 struct btrfs_trans_handle *trans;
1503 struct btrfs_device *device = NULL;
1504 char *sizestr;
1505 char *retptr;
1506 char *devstr = NULL;
1507 int ret = 0;
1508 int mod = 0;
1509
1510 if (!capable(CAP_SYS_ADMIN))
1511 return -EPERM;
1512
1513 ret = mnt_want_write_file(file);
1514 if (ret)
1515 return ret;
1516
1517 if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
1518 1)) {
1519 mnt_drop_write_file(file);
1520 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1521 }
1522
1523 mutex_lock(&root->fs_info->volume_mutex);
1524 vol_args = memdup_user(arg, sizeof(*vol_args));
1525 if (IS_ERR(vol_args)) {
1526 ret = PTR_ERR(vol_args);
1527 goto out;
1528 }
1529
1530 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1531
1532 sizestr = vol_args->name;
1533 devstr = strchr(sizestr, ':');
1534 if (devstr) {
1535 sizestr = devstr + 1;
1536 *devstr = '\0';
1537 devstr = vol_args->name;
1538 ret = kstrtoull(devstr, 10, &devid);
1539 if (ret)
1540 goto out_free;
1541 if (!devid) {
1542 ret = -EINVAL;
1543 goto out_free;
1544 }
1545 btrfs_info(root->fs_info, "resizing devid %llu", devid);
1546 }
1547
1548 device = btrfs_find_device(root->fs_info, devid, NULL, NULL);
1549 if (!device) {
1550 btrfs_info(root->fs_info, "resizer unable to find device %llu",
1551 devid);
1552 ret = -ENODEV;
1553 goto out_free;
1554 }
1555
1556 if (!device->writeable) {
1557 btrfs_info(root->fs_info,
1558 "resizer unable to apply on readonly device %llu",
1559 devid);
1560 ret = -EPERM;
1561 goto out_free;
1562 }
1563
1564 if (!strcmp(sizestr, "max"))
1565 new_size = device->bdev->bd_inode->i_size;
1566 else {
1567 if (sizestr[0] == '-') {
1568 mod = -1;
1569 sizestr++;
1570 } else if (sizestr[0] == '+') {
1571 mod = 1;
1572 sizestr++;
1573 }
1574 new_size = memparse(sizestr, &retptr);
1575 if (*retptr != '\0' || new_size == 0) {
1576 ret = -EINVAL;
1577 goto out_free;
1578 }
1579 }
1580
1581 if (device->is_tgtdev_for_dev_replace) {
1582 ret = -EPERM;
1583 goto out_free;
1584 }
1585
1586 old_size = device->total_bytes;
1587
1588 if (mod < 0) {
1589 if (new_size > old_size) {
1590 ret = -EINVAL;
1591 goto out_free;
1592 }
1593 new_size = old_size - new_size;
1594 } else if (mod > 0) {
1595 if (new_size > ULLONG_MAX - old_size) {
1596 ret = -ERANGE;
1597 goto out_free;
1598 }
1599 new_size = old_size + new_size;
1600 }
1601
1602 if (new_size < 256 * 1024 * 1024) {
1603 ret = -EINVAL;
1604 goto out_free;
1605 }
1606 if (new_size > device->bdev->bd_inode->i_size) {
1607 ret = -EFBIG;
1608 goto out_free;
1609 }
1610
1611 do_div(new_size, root->sectorsize);
1612 new_size *= root->sectorsize;
1613
1614 printk_in_rcu(KERN_INFO "BTRFS: new size for %s is %llu\n",
1615 rcu_str_deref(device->name), new_size);
1616
1617 if (new_size > old_size) {
1618 trans = btrfs_start_transaction(root, 0);
1619 if (IS_ERR(trans)) {
1620 ret = PTR_ERR(trans);
1621 goto out_free;
1622 }
1623 ret = btrfs_grow_device(trans, device, new_size);
1624 btrfs_commit_transaction(trans, root);
1625 } else if (new_size < old_size) {
1626 ret = btrfs_shrink_device(device, new_size);
1627 } /* equal, nothing need to do */
1628
1629 out_free:
1630 kfree(vol_args);
1631 out:
1632 mutex_unlock(&root->fs_info->volume_mutex);
1633 atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
1634 mnt_drop_write_file(file);
1635 return ret;
1636 }
1637
1638 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1639 char *name, unsigned long fd, int subvol,
1640 u64 *transid, bool readonly,
1641 struct btrfs_qgroup_inherit *inherit)
1642 {
1643 int namelen;
1644 int ret = 0;
1645
1646 ret = mnt_want_write_file(file);
1647 if (ret)
1648 goto out;
1649
1650 namelen = strlen(name);
1651 if (strchr(name, '/')) {
1652 ret = -EINVAL;
1653 goto out_drop_write;
1654 }
1655
1656 if (name[0] == '.' &&
1657 (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1658 ret = -EEXIST;
1659 goto out_drop_write;
1660 }
1661
1662 if (subvol) {
1663 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1664 NULL, transid, readonly, inherit);
1665 } else {
1666 struct fd src = fdget(fd);
1667 struct inode *src_inode;
1668 if (!src.file) {
1669 ret = -EINVAL;
1670 goto out_drop_write;
1671 }
1672
1673 src_inode = file_inode(src.file);
1674 if (src_inode->i_sb != file_inode(file)->i_sb) {
1675 btrfs_info(BTRFS_I(src_inode)->root->fs_info,
1676 "Snapshot src from another FS");
1677 ret = -EXDEV;
1678 } else if (!inode_owner_or_capable(src_inode)) {
1679 /*
1680 * Subvolume creation is not restricted, but snapshots
1681 * are limited to own subvolumes only
1682 */
1683 ret = -EPERM;
1684 } else {
1685 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1686 BTRFS_I(src_inode)->root,
1687 transid, readonly, inherit);
1688 }
1689 fdput(src);
1690 }
1691 out_drop_write:
1692 mnt_drop_write_file(file);
1693 out:
1694 return ret;
1695 }
1696
1697 static noinline int btrfs_ioctl_snap_create(struct file *file,
1698 void __user *arg, int subvol)
1699 {
1700 struct btrfs_ioctl_vol_args *vol_args;
1701 int ret;
1702
1703 vol_args = memdup_user(arg, sizeof(*vol_args));
1704 if (IS_ERR(vol_args))
1705 return PTR_ERR(vol_args);
1706 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1707
1708 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1709 vol_args->fd, subvol,
1710 NULL, false, NULL);
1711
1712 kfree(vol_args);
1713 return ret;
1714 }
1715
1716 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1717 void __user *arg, int subvol)
1718 {
1719 struct btrfs_ioctl_vol_args_v2 *vol_args;
1720 int ret;
1721 u64 transid = 0;
1722 u64 *ptr = NULL;
1723 bool readonly = false;
1724 struct btrfs_qgroup_inherit *inherit = NULL;
1725
1726 vol_args = memdup_user(arg, sizeof(*vol_args));
1727 if (IS_ERR(vol_args))
1728 return PTR_ERR(vol_args);
1729 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1730
1731 if (vol_args->flags &
1732 ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1733 BTRFS_SUBVOL_QGROUP_INHERIT)) {
1734 ret = -EOPNOTSUPP;
1735 goto out;
1736 }
1737
1738 if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1739 ptr = &transid;
1740 if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1741 readonly = true;
1742 if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1743 if (vol_args->size > PAGE_CACHE_SIZE) {
1744 ret = -EINVAL;
1745 goto out;
1746 }
1747 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1748 if (IS_ERR(inherit)) {
1749 ret = PTR_ERR(inherit);
1750 goto out;
1751 }
1752 }
1753
1754 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1755 vol_args->fd, subvol, ptr,
1756 readonly, inherit);
1757
1758 if (ret == 0 && ptr &&
1759 copy_to_user(arg +
1760 offsetof(struct btrfs_ioctl_vol_args_v2,
1761 transid), ptr, sizeof(*ptr)))
1762 ret = -EFAULT;
1763 out:
1764 kfree(vol_args);
1765 kfree(inherit);
1766 return ret;
1767 }
1768
1769 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1770 void __user *arg)
1771 {
1772 struct inode *inode = file_inode(file);
1773 struct btrfs_root *root = BTRFS_I(inode)->root;
1774 int ret = 0;
1775 u64 flags = 0;
1776
1777 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1778 return -EINVAL;
1779
1780 down_read(&root->fs_info->subvol_sem);
1781 if (btrfs_root_readonly(root))
1782 flags |= BTRFS_SUBVOL_RDONLY;
1783 up_read(&root->fs_info->subvol_sem);
1784
1785 if (copy_to_user(arg, &flags, sizeof(flags)))
1786 ret = -EFAULT;
1787
1788 return ret;
1789 }
1790
1791 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1792 void __user *arg)
1793 {
1794 struct inode *inode = file_inode(file);
1795 struct btrfs_root *root = BTRFS_I(inode)->root;
1796 struct btrfs_trans_handle *trans;
1797 u64 root_flags;
1798 u64 flags;
1799 int ret = 0;
1800
1801 if (!inode_owner_or_capable(inode))
1802 return -EPERM;
1803
1804 ret = mnt_want_write_file(file);
1805 if (ret)
1806 goto out;
1807
1808 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1809 ret = -EINVAL;
1810 goto out_drop_write;
1811 }
1812
1813 if (copy_from_user(&flags, arg, sizeof(flags))) {
1814 ret = -EFAULT;
1815 goto out_drop_write;
1816 }
1817
1818 if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1819 ret = -EINVAL;
1820 goto out_drop_write;
1821 }
1822
1823 if (flags & ~BTRFS_SUBVOL_RDONLY) {
1824 ret = -EOPNOTSUPP;
1825 goto out_drop_write;
1826 }
1827
1828 down_write(&root->fs_info->subvol_sem);
1829
1830 /* nothing to do */
1831 if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1832 goto out_drop_sem;
1833
1834 root_flags = btrfs_root_flags(&root->root_item);
1835 if (flags & BTRFS_SUBVOL_RDONLY) {
1836 btrfs_set_root_flags(&root->root_item,
1837 root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1838 } else {
1839 /*
1840 * Block RO -> RW transition if this subvolume is involved in
1841 * send
1842 */
1843 spin_lock(&root->root_item_lock);
1844 if (root->send_in_progress == 0) {
1845 btrfs_set_root_flags(&root->root_item,
1846 root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1847 spin_unlock(&root->root_item_lock);
1848 } else {
1849 spin_unlock(&root->root_item_lock);
1850 btrfs_warn(root->fs_info,
1851 "Attempt to set subvolume %llu read-write during send",
1852 root->root_key.objectid);
1853 ret = -EPERM;
1854 goto out_drop_sem;
1855 }
1856 }
1857
1858 trans = btrfs_start_transaction(root, 1);
1859 if (IS_ERR(trans)) {
1860 ret = PTR_ERR(trans);
1861 goto out_reset;
1862 }
1863
1864 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1865 &root->root_key, &root->root_item);
1866
1867 btrfs_commit_transaction(trans, root);
1868 out_reset:
1869 if (ret)
1870 btrfs_set_root_flags(&root->root_item, root_flags);
1871 out_drop_sem:
1872 up_write(&root->fs_info->subvol_sem);
1873 out_drop_write:
1874 mnt_drop_write_file(file);
1875 out:
1876 return ret;
1877 }
1878
1879 /*
1880 * helper to check if the subvolume references other subvolumes
1881 */
1882 static noinline int may_destroy_subvol(struct btrfs_root *root)
1883 {
1884 struct btrfs_path *path;
1885 struct btrfs_dir_item *di;
1886 struct btrfs_key key;
1887 u64 dir_id;
1888 int ret;
1889
1890 path = btrfs_alloc_path();
1891 if (!path)
1892 return -ENOMEM;
1893
1894 /* Make sure this root isn't set as the default subvol */
1895 dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
1896 di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root, path,
1897 dir_id, "default", 7, 0);
1898 if (di && !IS_ERR(di)) {
1899 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1900 if (key.objectid == root->root_key.objectid) {
1901 ret = -EPERM;
1902 btrfs_err(root->fs_info, "deleting default subvolume "
1903 "%llu is not allowed", key.objectid);
1904 goto out;
1905 }
1906 btrfs_release_path(path);
1907 }
1908
1909 key.objectid = root->root_key.objectid;
1910 key.type = BTRFS_ROOT_REF_KEY;
1911 key.offset = (u64)-1;
1912
1913 ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1914 &key, path, 0, 0);
1915 if (ret < 0)
1916 goto out;
1917 BUG_ON(ret == 0);
1918
1919 ret = 0;
1920 if (path->slots[0] > 0) {
1921 path->slots[0]--;
1922 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1923 if (key.objectid == root->root_key.objectid &&
1924 key.type == BTRFS_ROOT_REF_KEY)
1925 ret = -ENOTEMPTY;
1926 }
1927 out:
1928 btrfs_free_path(path);
1929 return ret;
1930 }
1931
1932 static noinline int key_in_sk(struct btrfs_key *key,
1933 struct btrfs_ioctl_search_key *sk)
1934 {
1935 struct btrfs_key test;
1936 int ret;
1937
1938 test.objectid = sk->min_objectid;
1939 test.type = sk->min_type;
1940 test.offset = sk->min_offset;
1941
1942 ret = btrfs_comp_cpu_keys(key, &test);
1943 if (ret < 0)
1944 return 0;
1945
1946 test.objectid = sk->max_objectid;
1947 test.type = sk->max_type;
1948 test.offset = sk->max_offset;
1949
1950 ret = btrfs_comp_cpu_keys(key, &test);
1951 if (ret > 0)
1952 return 0;
1953 return 1;
1954 }
1955
1956 static noinline int copy_to_sk(struct btrfs_root *root,
1957 struct btrfs_path *path,
1958 struct btrfs_key *key,
1959 struct btrfs_ioctl_search_key *sk,
1960 char *buf,
1961 unsigned long *sk_offset,
1962 int *num_found)
1963 {
1964 u64 found_transid;
1965 struct extent_buffer *leaf;
1966 struct btrfs_ioctl_search_header sh;
1967 unsigned long item_off;
1968 unsigned long item_len;
1969 int nritems;
1970 int i;
1971 int slot;
1972 int ret = 0;
1973
1974 leaf = path->nodes[0];
1975 slot = path->slots[0];
1976 nritems = btrfs_header_nritems(leaf);
1977
1978 if (btrfs_header_generation(leaf) > sk->max_transid) {
1979 i = nritems;
1980 goto advance_key;
1981 }
1982 found_transid = btrfs_header_generation(leaf);
1983
1984 for (i = slot; i < nritems; i++) {
1985 item_off = btrfs_item_ptr_offset(leaf, i);
1986 item_len = btrfs_item_size_nr(leaf, i);
1987
1988 btrfs_item_key_to_cpu(leaf, key, i);
1989 if (!key_in_sk(key, sk))
1990 continue;
1991
1992 if (sizeof(sh) + item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1993 item_len = 0;
1994
1995 if (sizeof(sh) + item_len + *sk_offset >
1996 BTRFS_SEARCH_ARGS_BUFSIZE) {
1997 ret = 1;
1998 goto overflow;
1999 }
2000
2001 sh.objectid = key->objectid;
2002 sh.offset = key->offset;
2003 sh.type = key->type;
2004 sh.len = item_len;
2005 sh.transid = found_transid;
2006
2007 /* copy search result header */
2008 memcpy(buf + *sk_offset, &sh, sizeof(sh));
2009 *sk_offset += sizeof(sh);
2010
2011 if (item_len) {
2012 char *p = buf + *sk_offset;
2013 /* copy the item */
2014 read_extent_buffer(leaf, p,
2015 item_off, item_len);
2016 *sk_offset += item_len;
2017 }
2018 (*num_found)++;
2019
2020 if (*num_found >= sk->nr_items)
2021 break;
2022 }
2023 advance_key:
2024 ret = 0;
2025 if (key->offset < (u64)-1 && key->offset < sk->max_offset)
2026 key->offset++;
2027 else if (key->type < (u8)-1 && key->type < sk->max_type) {
2028 key->offset = 0;
2029 key->type++;
2030 } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
2031 key->offset = 0;
2032 key->type = 0;
2033 key->objectid++;
2034 } else
2035 ret = 1;
2036 overflow:
2037 return ret;
2038 }
2039
2040 static noinline int search_ioctl(struct inode *inode,
2041 struct btrfs_ioctl_search_args *args)
2042 {
2043 struct btrfs_root *root;
2044 struct btrfs_key key;
2045 struct btrfs_path *path;
2046 struct btrfs_ioctl_search_key *sk = &args->key;
2047 struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
2048 int ret;
2049 int num_found = 0;
2050 unsigned long sk_offset = 0;
2051
2052 path = btrfs_alloc_path();
2053 if (!path)
2054 return -ENOMEM;
2055
2056 if (sk->tree_id == 0) {
2057 /* search the root of the inode that was passed */
2058 root = BTRFS_I(inode)->root;
2059 } else {
2060 key.objectid = sk->tree_id;
2061 key.type = BTRFS_ROOT_ITEM_KEY;
2062 key.offset = (u64)-1;
2063 root = btrfs_read_fs_root_no_name(info, &key);
2064 if (IS_ERR(root)) {
2065 printk(KERN_ERR "BTRFS: could not find root %llu\n",
2066 sk->tree_id);
2067 btrfs_free_path(path);
2068 return -ENOENT;
2069 }
2070 }
2071
2072 key.objectid = sk->min_objectid;
2073 key.type = sk->min_type;
2074 key.offset = sk->min_offset;
2075
2076 path->keep_locks = 1;
2077
2078 while (1) {
2079 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2080 if (ret != 0) {
2081 if (ret > 0)
2082 ret = 0;
2083 goto err;
2084 }
2085 ret = copy_to_sk(root, path, &key, sk, args->buf,
2086 &sk_offset, &num_found);
2087 btrfs_release_path(path);
2088 if (ret || num_found >= sk->nr_items)
2089 break;
2090
2091 }
2092 ret = 0;
2093 err:
2094 sk->nr_items = num_found;
2095 btrfs_free_path(path);
2096 return ret;
2097 }
2098
2099 static noinline int btrfs_ioctl_tree_search(struct file *file,
2100 void __user *argp)
2101 {
2102 struct btrfs_ioctl_search_args *args;
2103 struct inode *inode;
2104 int ret;
2105
2106 if (!capable(CAP_SYS_ADMIN))
2107 return -EPERM;
2108
2109 args = memdup_user(argp, sizeof(*args));
2110 if (IS_ERR(args))
2111 return PTR_ERR(args);
2112
2113 inode = file_inode(file);
2114 ret = search_ioctl(inode, args);
2115 if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2116 ret = -EFAULT;
2117 kfree(args);
2118 return ret;
2119 }
2120
2121 /*
2122 * Search INODE_REFs to identify path name of 'dirid' directory
2123 * in a 'tree_id' tree. and sets path name to 'name'.
2124 */
2125 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2126 u64 tree_id, u64 dirid, char *name)
2127 {
2128 struct btrfs_root *root;
2129 struct btrfs_key key;
2130 char *ptr;
2131 int ret = -1;
2132 int slot;
2133 int len;
2134 int total_len = 0;
2135 struct btrfs_inode_ref *iref;
2136 struct extent_buffer *l;
2137 struct btrfs_path *path;
2138
2139 if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2140 name[0]='\0';
2141 return 0;
2142 }
2143
2144 path = btrfs_alloc_path();
2145 if (!path)
2146 return -ENOMEM;
2147
2148 ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
2149
2150 key.objectid = tree_id;
2151 key.type = BTRFS_ROOT_ITEM_KEY;
2152 key.offset = (u64)-1;
2153 root = btrfs_read_fs_root_no_name(info, &key);
2154 if (IS_ERR(root)) {
2155 printk(KERN_ERR "BTRFS: could not find root %llu\n", tree_id);
2156 ret = -ENOENT;
2157 goto out;
2158 }
2159
2160 key.objectid = dirid;
2161 key.type = BTRFS_INODE_REF_KEY;
2162 key.offset = (u64)-1;
2163
2164 while (1) {
2165 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2166 if (ret < 0)
2167 goto out;
2168 else if (ret > 0) {
2169 ret = btrfs_previous_item(root, path, dirid,
2170 BTRFS_INODE_REF_KEY);
2171 if (ret < 0)
2172 goto out;
2173 else if (ret > 0) {
2174 ret = -ENOENT;
2175 goto out;
2176 }
2177 }
2178
2179 l = path->nodes[0];
2180 slot = path->slots[0];
2181 btrfs_item_key_to_cpu(l, &key, slot);
2182
2183 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2184 len = btrfs_inode_ref_name_len(l, iref);
2185 ptr -= len + 1;
2186 total_len += len + 1;
2187 if (ptr < name) {
2188 ret = -ENAMETOOLONG;
2189 goto out;
2190 }
2191
2192 *(ptr + len) = '/';
2193 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2194
2195 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2196 break;
2197
2198 btrfs_release_path(path);
2199 key.objectid = key.offset;
2200 key.offset = (u64)-1;
2201 dirid = key.objectid;
2202 }
2203 memmove(name, ptr, total_len);
2204 name[total_len] = '\0';
2205 ret = 0;
2206 out:
2207 btrfs_free_path(path);
2208 return ret;
2209 }
2210
2211 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2212 void __user *argp)
2213 {
2214 struct btrfs_ioctl_ino_lookup_args *args;
2215 struct inode *inode;
2216 int ret;
2217
2218 if (!capable(CAP_SYS_ADMIN))
2219 return -EPERM;
2220
2221 args = memdup_user(argp, sizeof(*args));
2222 if (IS_ERR(args))
2223 return PTR_ERR(args);
2224
2225 inode = file_inode(file);
2226
2227 if (args->treeid == 0)
2228 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2229
2230 ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2231 args->treeid, args->objectid,
2232 args->name);
2233
2234 if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2235 ret = -EFAULT;
2236
2237 kfree(args);
2238 return ret;
2239 }
2240
2241 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2242 void __user *arg)
2243 {
2244 struct dentry *parent = file->f_path.dentry;
2245 struct dentry *dentry;
2246 struct inode *dir = parent->d_inode;
2247 struct inode *inode;
2248 struct btrfs_root *root = BTRFS_I(dir)->root;
2249 struct btrfs_root *dest = NULL;
2250 struct btrfs_ioctl_vol_args *vol_args;
2251 struct btrfs_trans_handle *trans;
2252 struct btrfs_block_rsv block_rsv;
2253 u64 root_flags;
2254 u64 qgroup_reserved;
2255 int namelen;
2256 int ret;
2257 int err = 0;
2258
2259 vol_args = memdup_user(arg, sizeof(*vol_args));
2260 if (IS_ERR(vol_args))
2261 return PTR_ERR(vol_args);
2262
2263 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2264 namelen = strlen(vol_args->name);
2265 if (strchr(vol_args->name, '/') ||
2266 strncmp(vol_args->name, "..", namelen) == 0) {
2267 err = -EINVAL;
2268 goto out;
2269 }
2270
2271 err = mnt_want_write_file(file);
2272 if (err)
2273 goto out;
2274
2275
2276 err = mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT);
2277 if (err == -EINTR)
2278 goto out_drop_write;
2279 dentry = lookup_one_len(vol_args->name, parent, namelen);
2280 if (IS_ERR(dentry)) {
2281 err = PTR_ERR(dentry);
2282 goto out_unlock_dir;
2283 }
2284
2285 if (!dentry->d_inode) {
2286 err = -ENOENT;
2287 goto out_dput;
2288 }
2289
2290 inode = dentry->d_inode;
2291 dest = BTRFS_I(inode)->root;
2292 if (!capable(CAP_SYS_ADMIN)) {
2293 /*
2294 * Regular user. Only allow this with a special mount
2295 * option, when the user has write+exec access to the
2296 * subvol root, and when rmdir(2) would have been
2297 * allowed.
2298 *
2299 * Note that this is _not_ check that the subvol is
2300 * empty or doesn't contain data that we wouldn't
2301 * otherwise be able to delete.
2302 *
2303 * Users who want to delete empty subvols should try
2304 * rmdir(2).
2305 */
2306 err = -EPERM;
2307 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
2308 goto out_dput;
2309
2310 /*
2311 * Do not allow deletion if the parent dir is the same
2312 * as the dir to be deleted. That means the ioctl
2313 * must be called on the dentry referencing the root
2314 * of the subvol, not a random directory contained
2315 * within it.
2316 */
2317 err = -EINVAL;
2318 if (root == dest)
2319 goto out_dput;
2320
2321 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2322 if (err)
2323 goto out_dput;
2324 }
2325
2326 /* check if subvolume may be deleted by a user */
2327 err = btrfs_may_delete(dir, dentry, 1);
2328 if (err)
2329 goto out_dput;
2330
2331 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
2332 err = -EINVAL;
2333 goto out_dput;
2334 }
2335
2336 mutex_lock(&inode->i_mutex);
2337
2338 /*
2339 * Don't allow to delete a subvolume with send in progress. This is
2340 * inside the i_mutex so the error handling that has to drop the bit
2341 * again is not run concurrently.
2342 */
2343 spin_lock(&dest->root_item_lock);
2344 root_flags = btrfs_root_flags(&dest->root_item);
2345 if (dest->send_in_progress == 0) {
2346 btrfs_set_root_flags(&dest->root_item,
2347 root_flags | BTRFS_ROOT_SUBVOL_DEAD);
2348 spin_unlock(&dest->root_item_lock);
2349 } else {
2350 spin_unlock(&dest->root_item_lock);
2351 btrfs_warn(root->fs_info,
2352 "Attempt to delete subvolume %llu during send",
2353 dest->root_key.objectid);
2354 err = -EPERM;
2355 goto out_dput;
2356 }
2357
2358 err = d_invalidate(dentry);
2359 if (err)
2360 goto out_unlock;
2361
2362 down_write(&root->fs_info->subvol_sem);
2363
2364 err = may_destroy_subvol(dest);
2365 if (err)
2366 goto out_up_write;
2367
2368 btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
2369 /*
2370 * One for dir inode, two for dir entries, two for root
2371 * ref/backref.
2372 */
2373 err = btrfs_subvolume_reserve_metadata(root, &block_rsv,
2374 5, &qgroup_reserved, true);
2375 if (err)
2376 goto out_up_write;
2377
2378 trans = btrfs_start_transaction(root, 0);
2379 if (IS_ERR(trans)) {
2380 err = PTR_ERR(trans);
2381 goto out_release;
2382 }
2383 trans->block_rsv = &block_rsv;
2384 trans->bytes_reserved = block_rsv.size;
2385
2386 ret = btrfs_unlink_subvol(trans, root, dir,
2387 dest->root_key.objectid,
2388 dentry->d_name.name,
2389 dentry->d_name.len);
2390 if (ret) {
2391 err = ret;
2392 btrfs_abort_transaction(trans, root, ret);
2393 goto out_end_trans;
2394 }
2395
2396 btrfs_record_root_in_trans(trans, dest);
2397
2398 memset(&dest->root_item.drop_progress, 0,
2399 sizeof(dest->root_item.drop_progress));
2400 dest->root_item.drop_level = 0;
2401 btrfs_set_root_refs(&dest->root_item, 0);
2402
2403 if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
2404 ret = btrfs_insert_orphan_item(trans,
2405 root->fs_info->tree_root,
2406 dest->root_key.objectid);
2407 if (ret) {
2408 btrfs_abort_transaction(trans, root, ret);
2409 err = ret;
2410 goto out_end_trans;
2411 }
2412 }
2413
2414 ret = btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root,
2415 dest->root_item.uuid, BTRFS_UUID_KEY_SUBVOL,
2416 dest->root_key.objectid);
2417 if (ret && ret != -ENOENT) {
2418 btrfs_abort_transaction(trans, root, ret);
2419 err = ret;
2420 goto out_end_trans;
2421 }
2422 if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
2423 ret = btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root,
2424 dest->root_item.received_uuid,
2425 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
2426 dest->root_key.objectid);
2427 if (ret && ret != -ENOENT) {
2428 btrfs_abort_transaction(trans, root, ret);
2429 err = ret;
2430 goto out_end_trans;
2431 }
2432 }
2433
2434 out_end_trans:
2435 trans->block_rsv = NULL;
2436 trans->bytes_reserved = 0;
2437 ret = btrfs_end_transaction(trans, root);
2438 if (ret && !err)
2439 err = ret;
2440 inode->i_flags |= S_DEAD;
2441 out_release:
2442 btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);
2443 out_up_write:
2444 up_write(&root->fs_info->subvol_sem);
2445 out_unlock:
2446 if (err) {
2447 spin_lock(&dest->root_item_lock);
2448 root_flags = btrfs_root_flags(&dest->root_item);
2449 btrfs_set_root_flags(&dest->root_item,
2450 root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
2451 spin_unlock(&dest->root_item_lock);
2452 }
2453 mutex_unlock(&inode->i_mutex);
2454 if (!err) {
2455 shrink_dcache_sb(root->fs_info->sb);
2456 btrfs_invalidate_inodes(dest);
2457 d_delete(dentry);
2458 ASSERT(dest->send_in_progress == 0);
2459
2460 /* the last ref */
2461 if (dest->cache_inode) {
2462 iput(dest->cache_inode);
2463 dest->cache_inode = NULL;
2464 }
2465 }
2466 out_dput:
2467 dput(dentry);
2468 out_unlock_dir:
2469 mutex_unlock(&dir->i_mutex);
2470 out_drop_write:
2471 mnt_drop_write_file(file);
2472 out:
2473 kfree(vol_args);
2474 return err;
2475 }
2476
2477 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2478 {
2479 struct inode *inode = file_inode(file);
2480 struct btrfs_root *root = BTRFS_I(inode)->root;
2481 struct btrfs_ioctl_defrag_range_args *range;
2482 int ret;
2483
2484 ret = mnt_want_write_file(file);
2485 if (ret)
2486 return ret;
2487
2488 if (btrfs_root_readonly(root)) {
2489 ret = -EROFS;
2490 goto out;
2491 }
2492
2493 switch (inode->i_mode & S_IFMT) {
2494 case S_IFDIR:
2495 if (!capable(CAP_SYS_ADMIN)) {
2496 ret = -EPERM;
2497 goto out;
2498 }
2499 ret = btrfs_defrag_root(root);
2500 if (ret)
2501 goto out;
2502 ret = btrfs_defrag_root(root->fs_info->extent_root);
2503 break;
2504 case S_IFREG:
2505 if (!(file->f_mode & FMODE_WRITE)) {
2506 ret = -EINVAL;
2507 goto out;
2508 }
2509
2510 range = kzalloc(sizeof(*range), GFP_KERNEL);
2511 if (!range) {
2512 ret = -ENOMEM;
2513 goto out;
2514 }
2515
2516 if (argp) {
2517 if (copy_from_user(range, argp,
2518 sizeof(*range))) {
2519 ret = -EFAULT;
2520 kfree(range);
2521 goto out;
2522 }
2523 /* compression requires us to start the IO */
2524 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2525 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2526 range->extent_thresh = (u32)-1;
2527 }
2528 } else {
2529 /* the rest are all set to zero by kzalloc */
2530 range->len = (u64)-1;
2531 }
2532 ret = btrfs_defrag_file(file_inode(file), file,
2533 range, 0, 0);
2534 if (ret > 0)
2535 ret = 0;
2536 kfree(range);
2537 break;
2538 default:
2539 ret = -EINVAL;
2540 }
2541 out:
2542 mnt_drop_write_file(file);
2543 return ret;
2544 }
2545
2546 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2547 {
2548 struct btrfs_ioctl_vol_args *vol_args;
2549 int ret;
2550
2551 if (!capable(CAP_SYS_ADMIN))
2552 return -EPERM;
2553
2554 if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2555 1)) {
2556 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2557 }
2558
2559 mutex_lock(&root->fs_info->volume_mutex);
2560 vol_args = memdup_user(arg, sizeof(*vol_args));
2561 if (IS_ERR(vol_args)) {
2562 ret = PTR_ERR(vol_args);
2563 goto out;
2564 }
2565
2566 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2567 ret = btrfs_init_new_device(root, vol_args->name);
2568
2569 kfree(vol_args);
2570 out:
2571 mutex_unlock(&root->fs_info->volume_mutex);
2572 atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2573 return ret;
2574 }
2575
2576 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2577 {
2578 struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
2579 struct btrfs_ioctl_vol_args *vol_args;
2580 int ret;
2581
2582 if (!capable(CAP_SYS_ADMIN))
2583 return -EPERM;
2584
2585 ret = mnt_want_write_file(file);
2586 if (ret)
2587 return ret;
2588
2589 vol_args = memdup_user(arg, sizeof(*vol_args));
2590 if (IS_ERR(vol_args)) {
2591 ret = PTR_ERR(vol_args);
2592 goto out;
2593 }
2594
2595 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2596
2597 if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2598 1)) {
2599 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2600 goto out;
2601 }
2602
2603 mutex_lock(&root->fs_info->volume_mutex);
2604 ret = btrfs_rm_device(root, vol_args->name);
2605 mutex_unlock(&root->fs_info->volume_mutex);
2606 atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2607
2608 out:
2609 kfree(vol_args);
2610 mnt_drop_write_file(file);
2611 return ret;
2612 }
2613
2614 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2615 {
2616 struct btrfs_ioctl_fs_info_args *fi_args;
2617 struct btrfs_device *device;
2618 struct btrfs_device *next;
2619 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2620 int ret = 0;
2621
2622 fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2623 if (!fi_args)
2624 return -ENOMEM;
2625
2626 mutex_lock(&fs_devices->device_list_mutex);
2627 fi_args->num_devices = fs_devices->num_devices;
2628 memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2629
2630 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
2631 if (device->devid > fi_args->max_id)
2632 fi_args->max_id = device->devid;
2633 }
2634 mutex_unlock(&fs_devices->device_list_mutex);
2635
2636 fi_args->nodesize = root->fs_info->super_copy->nodesize;
2637 fi_args->sectorsize = root->fs_info->super_copy->sectorsize;
2638 fi_args->clone_alignment = root->fs_info->super_copy->sectorsize;
2639
2640 if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2641 ret = -EFAULT;
2642
2643 kfree(fi_args);
2644 return ret;
2645 }
2646
2647 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2648 {
2649 struct btrfs_ioctl_dev_info_args *di_args;
2650 struct btrfs_device *dev;
2651 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2652 int ret = 0;
2653 char *s_uuid = NULL;
2654
2655 di_args = memdup_user(arg, sizeof(*di_args));
2656 if (IS_ERR(di_args))
2657 return PTR_ERR(di_args);
2658
2659 if (!btrfs_is_empty_uuid(di_args->uuid))
2660 s_uuid = di_args->uuid;
2661
2662 mutex_lock(&fs_devices->device_list_mutex);
2663 dev = btrfs_find_device(root->fs_info, di_args->devid, s_uuid, NULL);
2664
2665 if (!dev) {
2666 ret = -ENODEV;
2667 goto out;
2668 }
2669
2670 di_args->devid = dev->devid;
2671 di_args->bytes_used = dev->bytes_used;
2672 di_args->total_bytes = dev->total_bytes;
2673 memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2674 if (dev->name) {
2675 struct rcu_string *name;
2676
2677 rcu_read_lock();
2678 name = rcu_dereference(dev->name);
2679 strncpy(di_args->path, name->str, sizeof(di_args->path));
2680 rcu_read_unlock();
2681 di_args->path[sizeof(di_args->path) - 1] = 0;
2682 } else {
2683 di_args->path[0] = '\0';
2684 }
2685
2686 out:
2687 mutex_unlock(&fs_devices->device_list_mutex);
2688 if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2689 ret = -EFAULT;
2690
2691 kfree(di_args);
2692 return ret;
2693 }
2694
2695 static struct page *extent_same_get_page(struct inode *inode, u64 off)
2696 {
2697 struct page *page;
2698 pgoff_t index;
2699 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2700
2701 index = off >> PAGE_CACHE_SHIFT;
2702
2703 page = grab_cache_page(inode->i_mapping, index);
2704 if (!page)
2705 return NULL;
2706
2707 if (!PageUptodate(page)) {
2708 if (extent_read_full_page_nolock(tree, page, btrfs_get_extent,
2709 0))
2710 return NULL;
2711 lock_page(page);
2712 if (!PageUptodate(page)) {
2713 unlock_page(page);
2714 page_cache_release(page);
2715 return NULL;
2716 }
2717 }
2718 unlock_page(page);
2719
2720 return page;
2721 }
2722
2723 static inline void lock_extent_range(struct inode *inode, u64 off, u64 len)
2724 {
2725 /* do any pending delalloc/csum calc on src, one way or
2726 another, and lock file content */
2727 while (1) {
2728 struct btrfs_ordered_extent *ordered;
2729 lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2730 ordered = btrfs_lookup_first_ordered_extent(inode,
2731 off + len - 1);
2732 if ((!ordered ||
2733 ordered->file_offset + ordered->len <= off ||
2734 ordered->file_offset >= off + len) &&
2735 !test_range_bit(&BTRFS_I(inode)->io_tree, off,
2736 off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
2737 if (ordered)
2738 btrfs_put_ordered_extent(ordered);
2739 break;
2740 }
2741 unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2742 if (ordered)
2743 btrfs_put_ordered_extent(ordered);
2744 btrfs_wait_ordered_range(inode, off, len);
2745 }
2746 }
2747
2748 static void btrfs_double_unlock(struct inode *inode1, u64 loff1,
2749 struct inode *inode2, u64 loff2, u64 len)
2750 {
2751 unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
2752 unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
2753
2754 mutex_unlock(&inode1->i_mutex);
2755 mutex_unlock(&inode2->i_mutex);
2756 }
2757
2758 static void btrfs_double_lock(struct inode *inode1, u64 loff1,
2759 struct inode *inode2, u64 loff2, u64 len)
2760 {
2761 if (inode1 < inode2) {
2762 swap(inode1, inode2);
2763 swap(loff1, loff2);
2764 }
2765
2766 mutex_lock_nested(&inode1->i_mutex, I_MUTEX_PARENT);
2767 lock_extent_range(inode1, loff1, len);
2768 if (inode1 != inode2) {
2769 mutex_lock_nested(&inode2->i_mutex, I_MUTEX_CHILD);
2770 lock_extent_range(inode2, loff2, len);
2771 }
2772 }
2773
2774 static int btrfs_cmp_data(struct inode *src, u64 loff, struct inode *dst,
2775 u64 dst_loff, u64 len)
2776 {
2777 int ret = 0;
2778 struct page *src_page, *dst_page;
2779 unsigned int cmp_len = PAGE_CACHE_SIZE;
2780 void *addr, *dst_addr;
2781
2782 while (len) {
2783 if (len < PAGE_CACHE_SIZE)
2784 cmp_len = len;
2785
2786 src_page = extent_same_get_page(src, loff);
2787 if (!src_page)
2788 return -EINVAL;
2789 dst_page = extent_same_get_page(dst, dst_loff);
2790 if (!dst_page) {
2791 page_cache_release(src_page);
2792 return -EINVAL;
2793 }
2794 addr = kmap_atomic(src_page);
2795 dst_addr = kmap_atomic(dst_page);
2796
2797 flush_dcache_page(src_page);
2798 flush_dcache_page(dst_page);
2799
2800 if (memcmp(addr, dst_addr, cmp_len))
2801 ret = BTRFS_SAME_DATA_DIFFERS;
2802
2803 kunmap_atomic(addr);
2804 kunmap_atomic(dst_addr);
2805 page_cache_release(src_page);
2806 page_cache_release(dst_page);
2807
2808 if (ret)
2809 break;
2810
2811 loff += cmp_len;
2812 dst_loff += cmp_len;
2813 len -= cmp_len;
2814 }
2815
2816 return ret;
2817 }
2818
2819 static int extent_same_check_offsets(struct inode *inode, u64 off, u64 len)
2820 {
2821 u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
2822
2823 if (off + len > inode->i_size || off + len < off)
2824 return -EINVAL;
2825 /* Check that we are block aligned - btrfs_clone() requires this */
2826 if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
2827 return -EINVAL;
2828
2829 return 0;
2830 }
2831
2832 static int btrfs_extent_same(struct inode *src, u64 loff, u64 len,
2833 struct inode *dst, u64 dst_loff)
2834 {
2835 int ret;
2836
2837 /*
2838 * btrfs_clone() can't handle extents in the same file
2839 * yet. Once that works, we can drop this check and replace it
2840 * with a check for the same inode, but overlapping extents.
2841 */
2842 if (src == dst)
2843 return -EINVAL;
2844
2845 btrfs_double_lock(src, loff, dst, dst_loff, len);
2846
2847 ret = extent_same_check_offsets(src, loff, len);
2848 if (ret)
2849 goto out_unlock;
2850
2851 ret = extent_same_check_offsets(dst, dst_loff, len);
2852 if (ret)
2853 goto out_unlock;
2854
2855 /* don't make the dst file partly checksummed */
2856 if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
2857 (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
2858 ret = -EINVAL;
2859 goto out_unlock;
2860 }
2861
2862 ret = btrfs_cmp_data(src, loff, dst, dst_loff, len);
2863 if (ret == 0)
2864 ret = btrfs_clone(src, dst, loff, len, len, dst_loff);
2865
2866 out_unlock:
2867 btrfs_double_unlock(src, loff, dst, dst_loff, len);
2868
2869 return ret;
2870 }
2871
2872 #define BTRFS_MAX_DEDUPE_LEN (16 * 1024 * 1024)
2873
2874 static long btrfs_ioctl_file_extent_same(struct file *file,
2875 struct btrfs_ioctl_same_args __user *argp)
2876 {
2877 struct btrfs_ioctl_same_args *same;
2878 struct btrfs_ioctl_same_extent_info *info;
2879 struct inode *src = file_inode(file);
2880 u64 off;
2881 u64 len;
2882 int i;
2883 int ret;
2884 unsigned long size;
2885 u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
2886 bool is_admin = capable(CAP_SYS_ADMIN);
2887 u16 count;
2888
2889 if (!(file->f_mode & FMODE_READ))
2890 return -EINVAL;
2891
2892 ret = mnt_want_write_file(file);
2893 if (ret)
2894 return ret;
2895
2896 if (get_user(count, &argp->dest_count)) {
2897 ret = -EFAULT;
2898 goto out;
2899 }
2900
2901 size = offsetof(struct btrfs_ioctl_same_args __user, info[count]);
2902
2903 same = memdup_user(argp, size);
2904
2905 if (IS_ERR(same)) {
2906 ret = PTR_ERR(same);
2907 goto out;
2908 }
2909
2910 off = same->logical_offset;
2911 len = same->length;
2912
2913 /*
2914 * Limit the total length we will dedupe for each operation.
2915 * This is intended to bound the total time spent in this
2916 * ioctl to something sane.
2917 */
2918 if (len > BTRFS_MAX_DEDUPE_LEN)
2919 len = BTRFS_MAX_DEDUPE_LEN;
2920
2921 if (WARN_ON_ONCE(bs < PAGE_CACHE_SIZE)) {
2922 /*
2923 * Btrfs does not support blocksize < page_size. As a
2924 * result, btrfs_cmp_data() won't correctly handle
2925 * this situation without an update.
2926 */
2927 ret = -EINVAL;
2928 goto out;
2929 }
2930
2931 ret = -EISDIR;
2932 if (S_ISDIR(src->i_mode))
2933 goto out;
2934
2935 ret = -EACCES;
2936 if (!S_ISREG(src->i_mode))
2937 goto out;
2938
2939 /* pre-format output fields to sane values */
2940 for (i = 0; i < count; i++) {
2941 same->info[i].bytes_deduped = 0ULL;
2942 same->info[i].status = 0;
2943 }
2944
2945 for (i = 0, info = same->info; i < count; i++, info++) {
2946 struct inode *dst;
2947 struct fd dst_file = fdget(info->fd);
2948 if (!dst_file.file) {
2949 info->status = -EBADF;
2950 continue;
2951 }
2952 dst = file_inode(dst_file.file);
2953
2954 if (!(is_admin || (dst_file.file->f_mode & FMODE_WRITE))) {
2955 info->status = -EINVAL;
2956 } else if (file->f_path.mnt != dst_file.file->f_path.mnt) {
2957 info->status = -EXDEV;
2958 } else if (S_ISDIR(dst->i_mode)) {
2959 info->status = -EISDIR;
2960 } else if (!S_ISREG(dst->i_mode)) {
2961 info->status = -EACCES;
2962 } else {
2963 info->status = btrfs_extent_same(src, off, len, dst,
2964 info->logical_offset);
2965 if (info->status == 0)
2966 info->bytes_deduped += len;
2967 }
2968 fdput(dst_file);
2969 }
2970
2971 ret = copy_to_user(argp, same, size);
2972 if (ret)
2973 ret = -EFAULT;
2974
2975 out:
2976 mnt_drop_write_file(file);
2977 return ret;
2978 }
2979
2980 /* Helper to check and see if this root currently has a ref on the given disk
2981 * bytenr. If it does then we need to update the quota for this root. This
2982 * doesn't do anything if quotas aren't enabled.
2983 */
2984 static int check_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2985 u64 disko)
2986 {
2987 struct seq_list tree_mod_seq_elem = {};
2988 struct ulist *roots;
2989 struct ulist_iterator uiter;
2990 struct ulist_node *root_node = NULL;
2991 int ret;
2992
2993 if (!root->fs_info->quota_enabled)
2994 return 1;
2995
2996 btrfs_get_tree_mod_seq(root->fs_info, &tree_mod_seq_elem);
2997 ret = btrfs_find_all_roots(trans, root->fs_info, disko,
2998 tree_mod_seq_elem.seq, &roots);
2999 if (ret < 0)
3000 goto out;
3001 ret = 0;
3002 ULIST_ITER_INIT(&uiter);
3003 while ((root_node = ulist_next(roots, &uiter))) {
3004 if (root_node->val == root->objectid) {
3005 ret = 1;
3006 break;
3007 }
3008 }
3009 ulist_free(roots);
3010 out:
3011 btrfs_put_tree_mod_seq(root->fs_info, &tree_mod_seq_elem);
3012 return ret;
3013 }
3014
3015 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3016 struct inode *inode,
3017 u64 endoff,
3018 const u64 destoff,
3019 const u64 olen)
3020 {
3021 struct btrfs_root *root = BTRFS_I(inode)->root;
3022 int ret;
3023
3024 inode_inc_iversion(inode);
3025 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3026 /*
3027 * We round up to the block size at eof when determining which
3028 * extents to clone above, but shouldn't round up the file size.
3029 */
3030 if (endoff > destoff + olen)
3031 endoff = destoff + olen;
3032 if (endoff > inode->i_size)
3033 btrfs_i_size_write(inode, endoff);
3034
3035 ret = btrfs_update_inode(trans, root, inode);
3036 if (ret) {
3037 btrfs_abort_transaction(trans, root, ret);
3038 btrfs_end_transaction(trans, root);
3039 goto out;
3040 }
3041 ret = btrfs_end_transaction(trans, root);
3042 out:
3043 return ret;
3044 }
3045
3046 /**
3047 * btrfs_clone() - clone a range from inode file to another
3048 *
3049 * @src: Inode to clone from
3050 * @inode: Inode to clone to
3051 * @off: Offset within source to start clone from
3052 * @olen: Original length, passed by user, of range to clone
3053 * @olen_aligned: Block-aligned value of olen, extent_same uses
3054 * identical values here
3055 * @destoff: Offset within @inode to start clone
3056 */
3057 static int btrfs_clone(struct inode *src, struct inode *inode,
3058 const u64 off, const u64 olen, const u64 olen_aligned,
3059 const u64 destoff)
3060 {
3061 struct btrfs_root *root = BTRFS_I(inode)->root;
3062 struct btrfs_path *path = NULL;
3063 struct extent_buffer *leaf;
3064 struct btrfs_trans_handle *trans;
3065 char *buf = NULL;
3066 struct btrfs_key key;
3067 u32 nritems;
3068 int slot;
3069 int ret;
3070 int no_quota;
3071 const u64 len = olen_aligned;
3072 u64 last_disko = 0;
3073 u64 last_dest_end = destoff;
3074
3075 ret = -ENOMEM;
3076 buf = vmalloc(btrfs_level_size(root, 0));
3077 if (!buf)
3078 return ret;
3079
3080 path = btrfs_alloc_path();
3081 if (!path) {
3082 vfree(buf);
3083 return ret;
3084 }
3085
3086 path->reada = 2;
3087 /* clone data */
3088 key.objectid = btrfs_ino(src);
3089 key.type = BTRFS_EXTENT_DATA_KEY;
3090 key.offset = off;
3091
3092 while (1) {
3093 /*
3094 * note the key will change type as we walk through the
3095 * tree.
3096 */
3097 path->leave_spinning = 1;
3098 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3099 0, 0);
3100 if (ret < 0)
3101 goto out;
3102 /*
3103 * First search, if no extent item that starts at offset off was
3104 * found but the previous item is an extent item, it's possible
3105 * it might overlap our target range, therefore process it.
3106 */
3107 if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3108 btrfs_item_key_to_cpu(path->nodes[0], &key,
3109 path->slots[0] - 1);
3110 if (key.type == BTRFS_EXTENT_DATA_KEY)
3111 path->slots[0]--;
3112 }
3113
3114 nritems = btrfs_header_nritems(path->nodes[0]);
3115 process_slot:
3116 no_quota = 1;
3117 if (path->slots[0] >= nritems) {
3118 ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3119 if (ret < 0)
3120 goto out;
3121 if (ret > 0)
3122 break;
3123 nritems = btrfs_header_nritems(path->nodes[0]);
3124 }
3125 leaf = path->nodes[0];
3126 slot = path->slots[0];
3127
3128 btrfs_item_key_to_cpu(leaf, &key, slot);
3129 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
3130 key.objectid != btrfs_ino(src))
3131 break;
3132
3133 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
3134 struct btrfs_file_extent_item *extent;
3135 int type;
3136 u32 size;
3137 struct btrfs_key new_key;
3138 u64 disko = 0, diskl = 0;
3139 u64 datao = 0, datal = 0;
3140 u8 comp;
3141 u64 drop_start;
3142
3143 extent = btrfs_item_ptr(leaf, slot,
3144 struct btrfs_file_extent_item);
3145 comp = btrfs_file_extent_compression(leaf, extent);
3146 type = btrfs_file_extent_type(leaf, extent);
3147 if (type == BTRFS_FILE_EXTENT_REG ||
3148 type == BTRFS_FILE_EXTENT_PREALLOC) {
3149 disko = btrfs_file_extent_disk_bytenr(leaf,
3150 extent);
3151 diskl = btrfs_file_extent_disk_num_bytes(leaf,
3152 extent);
3153 datao = btrfs_file_extent_offset(leaf, extent);
3154 datal = btrfs_file_extent_num_bytes(leaf,
3155 extent);
3156 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3157 /* take upper bound, may be compressed */
3158 datal = btrfs_file_extent_ram_bytes(leaf,
3159 extent);
3160 }
3161
3162 /*
3163 * The first search might have left us at an extent
3164 * item that ends before our target range's start, can
3165 * happen if we have holes and NO_HOLES feature enabled.
3166 */
3167 if (key.offset + datal <= off) {
3168 path->slots[0]++;
3169 goto process_slot;
3170 } else if (key.offset >= off + len) {
3171 break;
3172 }
3173
3174 size = btrfs_item_size_nr(leaf, slot);
3175 read_extent_buffer(leaf, buf,
3176 btrfs_item_ptr_offset(leaf, slot),
3177 size);
3178
3179 btrfs_release_path(path);
3180 path->leave_spinning = 0;
3181
3182 memcpy(&new_key, &key, sizeof(new_key));
3183 new_key.objectid = btrfs_ino(inode);
3184 if (off <= key.offset)
3185 new_key.offset = key.offset + destoff - off;
3186 else
3187 new_key.offset = destoff;
3188
3189 /*
3190 * Deal with a hole that doesn't have an extent item
3191 * that represents it (NO_HOLES feature enabled).
3192 * This hole is either in the middle of the cloning
3193 * range or at the beginning (fully overlaps it or
3194 * partially overlaps it).
3195 */
3196 if (new_key.offset != last_dest_end)
3197 drop_start = last_dest_end;
3198 else
3199 drop_start = new_key.offset;
3200
3201 /*
3202 * 1 - adjusting old extent (we may have to split it)
3203 * 1 - add new extent
3204 * 1 - inode update
3205 */
3206 trans = btrfs_start_transaction(root, 3);
3207 if (IS_ERR(trans)) {
3208 ret = PTR_ERR(trans);
3209 goto out;
3210 }
3211
3212 if (type == BTRFS_FILE_EXTENT_REG ||
3213 type == BTRFS_FILE_EXTENT_PREALLOC) {
3214 /*
3215 * a | --- range to clone ---| b
3216 * | ------------- extent ------------- |
3217 */
3218
3219 /* substract range b */
3220 if (key.offset + datal > off + len)
3221 datal = off + len - key.offset;
3222
3223 /* substract range a */
3224 if (off > key.offset) {
3225 datao += off - key.offset;
3226 datal -= off - key.offset;
3227 }
3228
3229 ret = btrfs_drop_extents(trans, root, inode,
3230 drop_start,
3231 new_key.offset + datal,
3232 1);
3233 if (ret) {
3234 if (ret != -EOPNOTSUPP)
3235 btrfs_abort_transaction(trans,
3236 root, ret);
3237 btrfs_end_transaction(trans, root);
3238 goto out;
3239 }
3240
3241 ret = btrfs_insert_empty_item(trans, root, path,
3242 &new_key, size);
3243 if (ret) {
3244 btrfs_abort_transaction(trans, root,
3245 ret);
3246 btrfs_end_transaction(trans, root);
3247 goto out;
3248 }
3249
3250 leaf = path->nodes[0];
3251 slot = path->slots[0];
3252 write_extent_buffer(leaf, buf,
3253 btrfs_item_ptr_offset(leaf, slot),
3254 size);
3255
3256 extent = btrfs_item_ptr(leaf, slot,
3257 struct btrfs_file_extent_item);
3258
3259 /* disko == 0 means it's a hole */
3260 if (!disko)
3261 datao = 0;
3262
3263 btrfs_set_file_extent_offset(leaf, extent,
3264 datao);
3265 btrfs_set_file_extent_num_bytes(leaf, extent,
3266 datal);
3267
3268 /*
3269 * We need to look up the roots that point at
3270 * this bytenr and see if the new root does. If
3271 * it does not we need to make sure we update
3272 * quotas appropriately.
3273 */
3274 if (disko && root != BTRFS_I(src)->root &&
3275 disko != last_disko) {
3276 no_quota = check_ref(trans, root,
3277 disko);
3278 if (no_quota < 0) {
3279 btrfs_abort_transaction(trans,
3280 root,
3281 ret);
3282 btrfs_end_transaction(trans,
3283 root);
3284 ret = no_quota;
3285 goto out;
3286 }
3287 }
3288
3289 if (disko) {
3290 inode_add_bytes(inode, datal);
3291 ret = btrfs_inc_extent_ref(trans, root,
3292 disko, diskl, 0,
3293 root->root_key.objectid,
3294 btrfs_ino(inode),
3295 new_key.offset - datao,
3296 no_quota);
3297 if (ret) {
3298 btrfs_abort_transaction(trans,
3299 root,
3300 ret);
3301 btrfs_end_transaction(trans,
3302 root);
3303 goto out;
3304
3305 }
3306 }
3307 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3308 u64 skip = 0;
3309 u64 trim = 0;
3310 u64 aligned_end = 0;
3311
3312 if (off > key.offset) {
3313 skip = off - key.offset;
3314 new_key.offset += skip;
3315 }
3316
3317 if (key.offset + datal > off + len)
3318 trim = key.offset + datal - (off + len);
3319
3320 if (comp && (skip || trim)) {
3321 ret = -EINVAL;
3322 btrfs_end_transaction(trans, root);
3323 goto out;
3324 }
3325 size -= skip + trim;
3326 datal -= skip + trim;
3327
3328 aligned_end = ALIGN(new_key.offset + datal,
3329 root->sectorsize);
3330 ret = btrfs_drop_extents(trans, root, inode,
3331 drop_start,
3332 aligned_end,
3333 1);
3334 if (ret) {
3335 if (ret != -EOPNOTSUPP)
3336 btrfs_abort_transaction(trans,
3337 root, ret);
3338 btrfs_end_transaction(trans, root);
3339 goto out;
3340 }
3341
3342 ret = btrfs_insert_empty_item(trans, root, path,
3343 &new_key, size);
3344 if (ret) {
3345 btrfs_abort_transaction(trans, root,
3346 ret);
3347 btrfs_end_transaction(trans, root);
3348 goto out;
3349 }
3350
3351 if (skip) {
3352 u32 start =
3353 btrfs_file_extent_calc_inline_size(0);
3354 memmove(buf+start, buf+start+skip,
3355 datal);
3356 }
3357
3358 leaf = path->nodes[0];
3359 slot = path->slots[0];
3360 write_extent_buffer(leaf, buf,
3361 btrfs_item_ptr_offset(leaf, slot),
3362 size);
3363 inode_add_bytes(inode, datal);
3364 }
3365
3366 btrfs_mark_buffer_dirty(leaf);
3367 btrfs_release_path(path);
3368
3369 last_dest_end = new_key.offset + datal;
3370 ret = clone_finish_inode_update(trans, inode,
3371 last_dest_end,
3372 destoff, olen);
3373 if (ret)
3374 goto out;
3375 if (new_key.offset + datal >= destoff + len)
3376 break;
3377 }
3378 btrfs_release_path(path);
3379 key.offset++;
3380 }
3381 ret = 0;
3382
3383 if (last_dest_end < destoff + len) {
3384 /*
3385 * We have an implicit hole (NO_HOLES feature is enabled) that
3386 * fully or partially overlaps our cloning range at its end.
3387 */
3388 btrfs_release_path(path);
3389
3390 /*
3391 * 1 - remove extent(s)
3392 * 1 - inode update
3393 */
3394 trans = btrfs_start_transaction(root, 2);
3395 if (IS_ERR(trans)) {
3396 ret = PTR_ERR(trans);
3397 goto out;
3398 }
3399 ret = btrfs_drop_extents(trans, root, inode,
3400 last_dest_end, destoff + len, 1);
3401 if (ret) {
3402 if (ret != -EOPNOTSUPP)
3403 btrfs_abort_transaction(trans, root, ret);
3404 btrfs_end_transaction(trans, root);
3405 goto out;
3406 }
3407 ret = clone_finish_inode_update(trans, inode, destoff + len,
3408 destoff, olen);
3409 }
3410
3411 out:
3412 btrfs_free_path(path);
3413 vfree(buf);
3414 return ret;
3415 }
3416
3417 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
3418 u64 off, u64 olen, u64 destoff)
3419 {
3420 struct inode *inode = file_inode(file);
3421 struct btrfs_root *root = BTRFS_I(inode)->root;
3422 struct fd src_file;
3423 struct inode *src;
3424 int ret;
3425 u64 len = olen;
3426 u64 bs = root->fs_info->sb->s_blocksize;
3427 int same_inode = 0;
3428
3429 /*
3430 * TODO:
3431 * - split compressed inline extents. annoying: we need to
3432 * decompress into destination's address_space (the file offset
3433 * may change, so source mapping won't do), then recompress (or
3434 * otherwise reinsert) a subrange.
3435 *
3436 * - split destination inode's inline extents. The inline extents can
3437 * be either compressed or non-compressed.
3438 */
3439
3440 /* the destination must be opened for writing */
3441 if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
3442 return -EINVAL;
3443
3444 if (btrfs_root_readonly(root))
3445 return -EROFS;
3446
3447 ret = mnt_want_write_file(file);
3448 if (ret)
3449 return ret;
3450
3451 src_file = fdget(srcfd);
3452 if (!src_file.file) {
3453 ret = -EBADF;
3454 goto out_drop_write;
3455 }
3456
3457 ret = -EXDEV;
3458 if (src_file.file->f_path.mnt != file->f_path.mnt)
3459 goto out_fput;
3460
3461 src = file_inode(src_file.file);
3462
3463 ret = -EINVAL;
3464 if (src == inode)
3465 same_inode = 1;
3466
3467 /* the src must be open for reading */
3468 if (!(src_file.file->f_mode & FMODE_READ))
3469 goto out_fput;
3470
3471 /* don't make the dst file partly checksummed */
3472 if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3473 (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
3474 goto out_fput;
3475
3476 ret = -EISDIR;
3477 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
3478 goto out_fput;
3479
3480 ret = -EXDEV;
3481 if (src->i_sb != inode->i_sb)
3482 goto out_fput;
3483
3484 if (!same_inode) {
3485 if (inode < src) {
3486 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
3487 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
3488 } else {
3489 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
3490 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
3491 }
3492 } else {
3493 mutex_lock(&src->i_mutex);
3494 }
3495
3496 /* determine range to clone */
3497 ret = -EINVAL;
3498 if (off + len > src->i_size || off + len < off)
3499 goto out_unlock;
3500 if (len == 0)
3501 olen = len = src->i_size - off;
3502 /* if we extend to eof, continue to block boundary */
3503 if (off + len == src->i_size)
3504 len = ALIGN(src->i_size, bs) - off;
3505
3506 /* verify the end result is block aligned */
3507 if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
3508 !IS_ALIGNED(destoff, bs))
3509 goto out_unlock;
3510
3511 /* verify if ranges are overlapped within the same file */
3512 if (same_inode) {
3513 if (destoff + len > off && destoff < off + len)
3514 goto out_unlock;
3515 }
3516
3517 if (destoff > inode->i_size) {
3518 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
3519 if (ret)
3520 goto out_unlock;
3521 }
3522
3523 /*
3524 * Lock the target range too. Right after we replace the file extent
3525 * items in the fs tree (which now point to the cloned data), we might
3526 * have a worker replace them with extent items relative to a write
3527 * operation that was issued before this clone operation (i.e. confront
3528 * with inode.c:btrfs_finish_ordered_io).
3529 */
3530 if (same_inode) {
3531 u64 lock_start = min_t(u64, off, destoff);
3532 u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
3533
3534 lock_extent_range(src, lock_start, lock_len);
3535 } else {
3536 lock_extent_range(src, off, len);
3537 lock_extent_range(inode, destoff, len);
3538 }
3539
3540 ret = btrfs_clone(src, inode, off, olen, len, destoff);
3541
3542 if (same_inode) {
3543 u64 lock_start = min_t(u64, off, destoff);
3544 u64 lock_end = max_t(u64, off, destoff) + len - 1;
3545
3546 unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
3547 } else {
3548 unlock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1);
3549 unlock_extent(&BTRFS_I(inode)->io_tree, destoff,
3550 destoff + len - 1);
3551 }
3552 /*
3553 * Truncate page cache pages so that future reads will see the cloned
3554 * data immediately and not the previous data.
3555 */
3556 truncate_inode_pages_range(&inode->i_data, destoff,
3557 PAGE_CACHE_ALIGN(destoff + len) - 1);
3558 out_unlock:
3559 if (!same_inode) {
3560 if (inode < src) {
3561 mutex_unlock(&src->i_mutex);
3562 mutex_unlock(&inode->i_mutex);
3563 } else {
3564 mutex_unlock(&inode->i_mutex);
3565 mutex_unlock(&src->i_mutex);
3566 }
3567 } else {
3568 mutex_unlock(&src->i_mutex);
3569 }
3570 out_fput:
3571 fdput(src_file);
3572 out_drop_write:
3573 mnt_drop_write_file(file);
3574 return ret;
3575 }
3576
3577 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
3578 {
3579 struct btrfs_ioctl_clone_range_args args;
3580
3581 if (copy_from_user(&args, argp, sizeof(args)))
3582 return -EFAULT;
3583 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
3584 args.src_length, args.dest_offset);
3585 }
3586
3587 /*
3588 * there are many ways the trans_start and trans_end ioctls can lead
3589 * to deadlocks. They should only be used by applications that
3590 * basically own the machine, and have a very in depth understanding
3591 * of all the possible deadlocks and enospc problems.
3592 */
3593 static long btrfs_ioctl_trans_start(struct file *file)
3594 {
3595 struct inode *inode = file_inode(file);
3596 struct btrfs_root *root = BTRFS_I(inode)->root;
3597 struct btrfs_trans_handle *trans;
3598 int ret;
3599
3600 ret = -EPERM;
3601 if (!capable(CAP_SYS_ADMIN))
3602 goto out;
3603
3604 ret = -EINPROGRESS;
3605 if (file->private_data)
3606 goto out;
3607
3608 ret = -EROFS;
3609 if (btrfs_root_readonly(root))
3610 goto out;
3611
3612 ret = mnt_want_write_file(file);
3613 if (ret)
3614 goto out;
3615
3616 atomic_inc(&root->fs_info->open_ioctl_trans);
3617
3618 ret = -ENOMEM;
3619 trans = btrfs_start_ioctl_transaction(root);
3620 if (IS_ERR(trans))
3621 goto out_drop;
3622
3623 file->private_data = trans;
3624 return 0;
3625
3626 out_drop:
3627 atomic_dec(&root->fs_info->open_ioctl_trans);
3628 mnt_drop_write_file(file);
3629 out:
3630 return ret;
3631 }
3632
3633 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
3634 {
3635 struct inode *inode = file_inode(file);
3636 struct btrfs_root *root = BTRFS_I(inode)->root;
3637 struct btrfs_root *new_root;
3638 struct btrfs_dir_item *di;
3639 struct btrfs_trans_handle *trans;
3640 struct btrfs_path *path;
3641 struct btrfs_key location;
3642 struct btrfs_disk_key disk_key;
3643 u64 objectid = 0;
3644 u64 dir_id;
3645 int ret;
3646
3647 if (!capable(CAP_SYS_ADMIN))
3648 return -EPERM;
3649
3650 ret = mnt_want_write_file(file);
3651 if (ret)
3652 return ret;
3653
3654 if (copy_from_user(&objectid, argp, sizeof(objectid))) {
3655 ret = -EFAULT;
3656 goto out;
3657 }
3658
3659 if (!objectid)
3660 objectid = BTRFS_FS_TREE_OBJECTID;
3661
3662 location.objectid = objectid;
3663 location.type = BTRFS_ROOT_ITEM_KEY;
3664 location.offset = (u64)-1;
3665
3666 new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
3667 if (IS_ERR(new_root)) {
3668 ret = PTR_ERR(new_root);
3669 goto out;
3670 }
3671
3672 path = btrfs_alloc_path();
3673 if (!path) {
3674 ret = -ENOMEM;
3675 goto out;
3676 }
3677 path->leave_spinning = 1;
3678
3679 trans = btrfs_start_transaction(root, 1);
3680 if (IS_ERR(trans)) {
3681 btrfs_free_path(path);
3682 ret = PTR_ERR(trans);
3683 goto out;
3684 }
3685
3686 dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
3687 di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
3688 dir_id, "default", 7, 1);
3689 if (IS_ERR_OR_NULL(di)) {
3690 btrfs_free_path(path);
3691 btrfs_end_transaction(trans, root);
3692 btrfs_err(new_root->fs_info, "Umm, you don't have the default dir"
3693 "item, this isn't going to work");
3694 ret = -ENOENT;
3695 goto out;
3696 }
3697
3698 btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
3699 btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
3700 btrfs_mark_buffer_dirty(path->nodes[0]);
3701 btrfs_free_path(path);
3702
3703 btrfs_set_fs_incompat(root->fs_info, DEFAULT_SUBVOL);
3704 btrfs_end_transaction(trans, root);
3705 out:
3706 mnt_drop_write_file(file);
3707 return ret;
3708 }
3709
3710 void btrfs_get_block_group_info(struct list_head *groups_list,
3711 struct btrfs_ioctl_space_info *space)
3712 {
3713 struct btrfs_block_group_cache *block_group;
3714
3715 space->total_bytes = 0;
3716 space->used_bytes = 0;
3717 space->flags = 0;
3718 list_for_each_entry(block_group, groups_list, list) {
3719 space->flags = block_group->flags;
3720 space->total_bytes += block_group->key.offset;
3721 space->used_bytes +=
3722 btrfs_block_group_used(&block_group->item);
3723 }
3724 }
3725
3726 static long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
3727 {
3728 struct btrfs_ioctl_space_args space_args;
3729 struct btrfs_ioctl_space_info space;
3730 struct btrfs_ioctl_space_info *dest;
3731 struct btrfs_ioctl_space_info *dest_orig;
3732 struct btrfs_ioctl_space_info __user *user_dest;
3733 struct btrfs_space_info *info;
3734 u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
3735 BTRFS_BLOCK_GROUP_SYSTEM,
3736 BTRFS_BLOCK_GROUP_METADATA,
3737 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
3738 int num_types = 4;
3739 int alloc_size;
3740 int ret = 0;
3741 u64 slot_count = 0;
3742 int i, c;
3743
3744 if (copy_from_user(&space_args,
3745 (struct btrfs_ioctl_space_args __user *)arg,
3746 sizeof(space_args)))
3747 return -EFAULT;
3748
3749 for (i = 0; i < num_types; i++) {
3750 struct btrfs_space_info *tmp;
3751
3752 info = NULL;
3753 rcu_read_lock();
3754 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
3755 list) {
3756 if (tmp->flags == types[i]) {
3757 info = tmp;
3758 break;
3759 }
3760 }
3761 rcu_read_unlock();
3762
3763 if (!info)
3764 continue;
3765
3766 down_read(&info->groups_sem);
3767 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3768 if (!list_empty(&info->block_groups[c]))
3769 slot_count++;
3770 }
3771 up_read(&info->groups_sem);
3772 }
3773
3774 /*
3775 * Global block reserve, exported as a space_info
3776 */
3777 slot_count++;
3778
3779 /* space_slots == 0 means they are asking for a count */
3780 if (space_args.space_slots == 0) {
3781 space_args.total_spaces = slot_count;
3782 goto out;
3783 }
3784
3785 slot_count = min_t(u64, space_args.space_slots, slot_count);
3786
3787 alloc_size = sizeof(*dest) * slot_count;
3788
3789 /* we generally have at most 6 or so space infos, one for each raid
3790 * level. So, a whole page should be more than enough for everyone
3791 */
3792 if (alloc_size > PAGE_CACHE_SIZE)
3793 return -ENOMEM;
3794
3795 space_args.total_spaces = 0;
3796 dest = kmalloc(alloc_size, GFP_NOFS);
3797 if (!dest)
3798 return -ENOMEM;
3799 dest_orig = dest;
3800
3801 /* now we have a buffer to copy into */
3802 for (i = 0; i < num_types; i++) {
3803 struct btrfs_space_info *tmp;
3804
3805 if (!slot_count)
3806 break;
3807
3808 info = NULL;
3809 rcu_read_lock();
3810 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
3811 list) {
3812 if (tmp->flags == types[i]) {
3813 info = tmp;
3814 break;
3815 }
3816 }
3817 rcu_read_unlock();
3818
3819 if (!info)
3820 continue;
3821 down_read(&info->groups_sem);
3822 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3823 if (!list_empty(&info->block_groups[c])) {
3824 btrfs_get_block_group_info(
3825 &info->block_groups[c], &space);
3826 memcpy(dest, &space, sizeof(space));
3827 dest++;
3828 space_args.total_spaces++;
3829 slot_count--;
3830 }
3831 if (!slot_count)
3832 break;
3833 }
3834 up_read(&info->groups_sem);
3835 }
3836
3837 /*
3838 * Add global block reserve
3839 */
3840 if (slot_count) {
3841 struct btrfs_block_rsv *block_rsv = &root->fs_info->global_block_rsv;
3842
3843 spin_lock(&block_rsv->lock);
3844 space.total_bytes = block_rsv->size;
3845 space.used_bytes = block_rsv->size - block_rsv->reserved;
3846 spin_unlock(&block_rsv->lock);
3847 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
3848 memcpy(dest, &space, sizeof(space));
3849 space_args.total_spaces++;
3850 }
3851
3852 user_dest = (struct btrfs_ioctl_space_info __user *)
3853 (arg + sizeof(struct btrfs_ioctl_space_args));
3854
3855 if (copy_to_user(user_dest, dest_orig, alloc_size))
3856 ret = -EFAULT;
3857
3858 kfree(dest_orig);
3859 out:
3860 if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
3861 ret = -EFAULT;
3862
3863 return ret;
3864 }
3865
3866 /*
3867 * there are many ways the trans_start and trans_end ioctls can lead
3868 * to deadlocks. They should only be used by applications that
3869 * basically own the machine, and have a very in depth understanding
3870 * of all the possible deadlocks and enospc problems.
3871 */
3872 long btrfs_ioctl_trans_end(struct file *file)
3873 {
3874 struct inode *inode = file_inode(file);
3875 struct btrfs_root *root = BTRFS_I(inode)->root;
3876 struct btrfs_trans_handle *trans;
3877
3878 trans = file->private_data;
3879 if (!trans)
3880 return -EINVAL;
3881 file->private_data = NULL;
3882
3883 btrfs_end_transaction(trans, root);
3884
3885 atomic_dec(&root->fs_info->open_ioctl_trans);
3886
3887 mnt_drop_write_file(file);
3888 return 0;
3889 }
3890
3891 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
3892 void __user *argp)
3893 {
3894 struct btrfs_trans_handle *trans;
3895 u64 transid;
3896 int ret;
3897
3898 trans = btrfs_attach_transaction_barrier(root);
3899 if (IS_ERR(trans)) {
3900 if (PTR_ERR(trans) != -ENOENT)
3901 return PTR_ERR(trans);
3902
3903 /* No running transaction, don't bother */
3904 transid = root->fs_info->last_trans_committed;
3905 goto out;
3906 }
3907 transid = trans->transid;
3908 ret = btrfs_commit_transaction_async(trans, root, 0);
3909 if (ret) {
3910 btrfs_end_transaction(trans, root);
3911 return ret;
3912 }
3913 out:
3914 if (argp)
3915 if (copy_to_user(argp, &transid, sizeof(transid)))
3916 return -EFAULT;
3917 return 0;
3918 }
3919
3920 static noinline long btrfs_ioctl_wait_sync(struct btrfs_root *root,
3921 void __user *argp)
3922 {
3923 u64 transid;
3924
3925 if (argp) {
3926 if (copy_from_user(&transid, argp, sizeof(transid)))
3927 return -EFAULT;
3928 } else {
3929 transid = 0; /* current trans */
3930 }
3931 return btrfs_wait_for_commit(root, transid);
3932 }
3933
3934 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
3935 {
3936 struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3937 struct btrfs_ioctl_scrub_args *sa;
3938 int ret;
3939
3940 if (!capable(CAP_SYS_ADMIN))
3941 return -EPERM;
3942
3943 sa = memdup_user(arg, sizeof(*sa));
3944 if (IS_ERR(sa))
3945 return PTR_ERR(sa);
3946
3947 if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
3948 ret = mnt_want_write_file(file);
3949 if (ret)
3950 goto out;
3951 }
3952
3953 ret = btrfs_scrub_dev(root->fs_info, sa->devid, sa->start, sa->end,
3954 &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
3955 0);
3956
3957 if (copy_to_user(arg, sa, sizeof(*sa)))
3958 ret = -EFAULT;
3959
3960 if (!(sa->flags & BTRFS_SCRUB_READONLY))
3961 mnt_drop_write_file(file);
3962 out:
3963 kfree(sa);
3964 return ret;
3965 }
3966
3967 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
3968 {
3969 if (!capable(CAP_SYS_ADMIN))
3970 return -EPERM;
3971
3972 return btrfs_scrub_cancel(root->fs_info);
3973 }
3974
3975 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
3976 void __user *arg)
3977 {
3978 struct btrfs_ioctl_scrub_args *sa;
3979 int ret;
3980
3981 if (!capable(CAP_SYS_ADMIN))
3982 return -EPERM;
3983
3984 sa = memdup_user(arg, sizeof(*sa));
3985 if (IS_ERR(sa))
3986 return PTR_ERR(sa);
3987
3988 ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
3989
3990 if (copy_to_user(arg, sa, sizeof(*sa)))
3991 ret = -EFAULT;
3992
3993 kfree(sa);
3994 return ret;
3995 }
3996
3997 static long btrfs_ioctl_get_dev_stats(struct btrfs_root *root,
3998 void __user *arg)
3999 {
4000 struct btrfs_ioctl_get_dev_stats *sa;
4001 int ret;
4002
4003 sa = memdup_user(arg, sizeof(*sa));
4004 if (IS_ERR(sa))
4005 return PTR_ERR(sa);
4006
4007 if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4008 kfree(sa);
4009 return -EPERM;
4010 }
4011
4012 ret = btrfs_get_dev_stats(root, sa);
4013
4014 if (copy_to_user(arg, sa, sizeof(*sa)))
4015 ret = -EFAULT;
4016
4017 kfree(sa);
4018 return ret;
4019 }
4020
4021 static long btrfs_ioctl_dev_replace(struct btrfs_root *root, void __user *arg)
4022 {
4023 struct btrfs_ioctl_dev_replace_args *p;
4024 int ret;
4025
4026 if (!capable(CAP_SYS_ADMIN))
4027 return -EPERM;
4028
4029 p = memdup_user(arg, sizeof(*p));
4030 if (IS_ERR(p))
4031 return PTR_ERR(p);
4032
4033 switch (p->cmd) {
4034 case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4035 if (root->fs_info->sb->s_flags & MS_RDONLY) {
4036 ret = -EROFS;
4037 goto out;
4038 }
4039 if (atomic_xchg(
4040 &root->fs_info->mutually_exclusive_operation_running,
4041 1)) {
4042 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4043 } else {
4044 ret = btrfs_dev_replace_start(root, p);
4045 atomic_set(
4046 &root->fs_info->mutually_exclusive_operation_running,
4047 0);
4048 }
4049 break;
4050 case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4051 btrfs_dev_replace_status(root->fs_info, p);
4052 ret = 0;
4053 break;
4054 case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4055 ret = btrfs_dev_replace_cancel(root->fs_info, p);
4056 break;
4057 default:
4058 ret = -EINVAL;
4059 break;
4060 }
4061
4062 if (copy_to_user(arg, p, sizeof(*p)))
4063 ret = -EFAULT;
4064 out:
4065 kfree(p);
4066 return ret;
4067 }
4068
4069 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4070 {
4071 int ret = 0;
4072 int i;
4073 u64 rel_ptr;
4074 int size;
4075 struct btrfs_ioctl_ino_path_args *ipa = NULL;
4076 struct inode_fs_paths *ipath = NULL;
4077 struct btrfs_path *path;
4078
4079 if (!capable(CAP_DAC_READ_SEARCH))
4080 return -EPERM;
4081
4082 path = btrfs_alloc_path();
4083 if (!path) {
4084 ret = -ENOMEM;
4085 goto out;
4086 }
4087
4088 ipa = memdup_user(arg, sizeof(*ipa));
4089 if (IS_ERR(ipa)) {
4090 ret = PTR_ERR(ipa);
4091 ipa = NULL;
4092 goto out;
4093 }
4094
4095 size = min_t(u32, ipa->size, 4096);
4096 ipath = init_ipath(size, root, path);
4097 if (IS_ERR(ipath)) {
4098 ret = PTR_ERR(ipath);
4099 ipath = NULL;
4100 goto out;
4101 }
4102
4103 ret = paths_from_inode(ipa->inum, ipath);
4104 if (ret < 0)
4105 goto out;
4106
4107 for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4108 rel_ptr = ipath->fspath->val[i] -
4109 (u64)(unsigned long)ipath->fspath->val;
4110 ipath->fspath->val[i] = rel_ptr;
4111 }
4112
4113 ret = copy_to_user((void *)(unsigned long)ipa->fspath,
4114 (void *)(unsigned long)ipath->fspath, size);
4115 if (ret) {
4116 ret = -EFAULT;
4117 goto out;
4118 }
4119
4120 out:
4121 btrfs_free_path(path);
4122 free_ipath(ipath);
4123 kfree(ipa);
4124
4125 return ret;
4126 }
4127
4128 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4129 {
4130 struct btrfs_data_container *inodes = ctx;
4131 const size_t c = 3 * sizeof(u64);
4132
4133 if (inodes->bytes_left >= c) {
4134 inodes->bytes_left -= c;
4135 inodes->val[inodes->elem_cnt] = inum;
4136 inodes->val[inodes->elem_cnt + 1] = offset;
4137 inodes->val[inodes->elem_cnt + 2] = root;
4138 inodes->elem_cnt += 3;
4139 } else {
4140 inodes->bytes_missing += c - inodes->bytes_left;
4141 inodes->bytes_left = 0;
4142 inodes->elem_missed += 3;
4143 }
4144
4145 return 0;
4146 }
4147
4148 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
4149 void __user *arg)
4150 {
4151 int ret = 0;
4152 int size;
4153 struct btrfs_ioctl_logical_ino_args *loi;
4154 struct btrfs_data_container *inodes = NULL;
4155 struct btrfs_path *path = NULL;
4156
4157 if (!capable(CAP_SYS_ADMIN))
4158 return -EPERM;
4159
4160 loi = memdup_user(arg, sizeof(*loi));
4161 if (IS_ERR(loi)) {
4162 ret = PTR_ERR(loi);
4163 loi = NULL;
4164 goto out;
4165 }
4166
4167 path = btrfs_alloc_path();
4168 if (!path) {
4169 ret = -ENOMEM;
4170 goto out;
4171 }
4172
4173 size = min_t(u32, loi->size, 64 * 1024);
4174 inodes = init_data_container(size);
4175 if (IS_ERR(inodes)) {
4176 ret = PTR_ERR(inodes);
4177 inodes = NULL;
4178 goto out;
4179 }
4180
4181 ret = iterate_inodes_from_logical(loi->logical, root->fs_info, path,
4182 build_ino_list, inodes);
4183 if (ret == -EINVAL)
4184 ret = -ENOENT;
4185 if (ret < 0)
4186 goto out;
4187
4188 ret = copy_to_user((void *)(unsigned long)loi->inodes,
4189 (void *)(unsigned long)inodes, size);
4190 if (ret)
4191 ret = -EFAULT;
4192
4193 out:
4194 btrfs_free_path(path);
4195 vfree(inodes);
4196 kfree(loi);
4197
4198 return ret;
4199 }
4200
4201 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
4202 struct btrfs_ioctl_balance_args *bargs)
4203 {
4204 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4205
4206 bargs->flags = bctl->flags;
4207
4208 if (atomic_read(&fs_info->balance_running))
4209 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4210 if (atomic_read(&fs_info->balance_pause_req))
4211 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4212 if (atomic_read(&fs_info->balance_cancel_req))
4213 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4214
4215 memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4216 memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4217 memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4218
4219 if (lock) {
4220 spin_lock(&fs_info->balance_lock);
4221 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4222 spin_unlock(&fs_info->balance_lock);
4223 } else {
4224 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4225 }
4226 }
4227
4228 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4229 {
4230 struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4231 struct btrfs_fs_info *fs_info = root->fs_info;
4232 struct btrfs_ioctl_balance_args *bargs;
4233 struct btrfs_balance_control *bctl;
4234 bool need_unlock; /* for mut. excl. ops lock */
4235 int ret;
4236
4237 if (!capable(CAP_SYS_ADMIN))
4238 return -EPERM;
4239
4240 ret = mnt_want_write_file(file);
4241 if (ret)
4242 return ret;
4243
4244 again:
4245 if (!atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
4246 mutex_lock(&fs_info->volume_mutex);
4247 mutex_lock(&fs_info->balance_mutex);
4248 need_unlock = true;
4249 goto locked;
4250 }
4251
4252 /*
4253 * mut. excl. ops lock is locked. Three possibilites:
4254 * (1) some other op is running
4255 * (2) balance is running
4256 * (3) balance is paused -- special case (think resume)
4257 */
4258 mutex_lock(&fs_info->balance_mutex);
4259 if (fs_info->balance_ctl) {
4260 /* this is either (2) or (3) */
4261 if (!atomic_read(&fs_info->balance_running)) {
4262 mutex_unlock(&fs_info->balance_mutex);
4263 if (!mutex_trylock(&fs_info->volume_mutex))
4264 goto again;
4265 mutex_lock(&fs_info->balance_mutex);
4266
4267 if (fs_info->balance_ctl &&
4268 !atomic_read(&fs_info->balance_running)) {
4269 /* this is (3) */
4270 need_unlock = false;
4271 goto locked;
4272 }
4273
4274 mutex_unlock(&fs_info->balance_mutex);
4275 mutex_unlock(&fs_info->volume_mutex);
4276 goto again;
4277 } else {
4278 /* this is (2) */
4279 mutex_unlock(&fs_info->balance_mutex);
4280 ret = -EINPROGRESS;
4281 goto out;
4282 }
4283 } else {
4284 /* this is (1) */
4285 mutex_unlock(&fs_info->balance_mutex);
4286 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4287 goto out;
4288 }
4289
4290 locked:
4291 BUG_ON(!atomic_read(&fs_info->mutually_exclusive_operation_running));
4292
4293 if (arg) {
4294 bargs = memdup_user(arg, sizeof(*bargs));
4295 if (IS_ERR(bargs)) {
4296 ret = PTR_ERR(bargs);
4297 goto out_unlock;
4298 }
4299
4300 if (bargs->flags & BTRFS_BALANCE_RESUME) {
4301 if (!fs_info->balance_ctl) {
4302 ret = -ENOTCONN;
4303 goto out_bargs;
4304 }
4305
4306 bctl = fs_info->balance_ctl;
4307 spin_lock(&fs_info->balance_lock);
4308 bctl->flags |= BTRFS_BALANCE_RESUME;
4309 spin_unlock(&fs_info->balance_lock);
4310
4311 goto do_balance;
4312 }
4313 } else {
4314 bargs = NULL;
4315 }
4316
4317 if (fs_info->balance_ctl) {
4318 ret = -EINPROGRESS;
4319 goto out_bargs;
4320 }
4321
4322 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
4323 if (!bctl) {
4324 ret = -ENOMEM;
4325 goto out_bargs;
4326 }
4327
4328 bctl->fs_info = fs_info;
4329 if (arg) {
4330 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4331 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4332 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4333
4334 bctl->flags = bargs->flags;
4335 } else {
4336 /* balance everything - no filters */
4337 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4338 }
4339
4340 do_balance:
4341 /*
4342 * Ownership of bctl and mutually_exclusive_operation_running
4343 * goes to to btrfs_balance. bctl is freed in __cancel_balance,
4344 * or, if restriper was paused all the way until unmount, in
4345 * free_fs_info. mutually_exclusive_operation_running is
4346 * cleared in __cancel_balance.
4347 */
4348 need_unlock = false;
4349
4350 ret = btrfs_balance(bctl, bargs);
4351
4352 if (arg) {
4353 if (copy_to_user(arg, bargs, sizeof(*bargs)))
4354 ret = -EFAULT;
4355 }
4356
4357 out_bargs:
4358 kfree(bargs);
4359 out_unlock:
4360 mutex_unlock(&fs_info->balance_mutex);
4361 mutex_unlock(&fs_info->volume_mutex);
4362 if (need_unlock)
4363 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
4364 out:
4365 mnt_drop_write_file(file);
4366 return ret;
4367 }
4368
4369 static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
4370 {
4371 if (!capable(CAP_SYS_ADMIN))
4372 return -EPERM;
4373
4374 switch (cmd) {
4375 case BTRFS_BALANCE_CTL_PAUSE:
4376 return btrfs_pause_balance(root->fs_info);
4377 case BTRFS_BALANCE_CTL_CANCEL:
4378 return btrfs_cancel_balance(root->fs_info);
4379 }
4380
4381 return -EINVAL;
4382 }
4383
4384 static long btrfs_ioctl_balance_progress(struct btrfs_root *root,
4385 void __user *arg)
4386 {
4387 struct btrfs_fs_info *fs_info = root->fs_info;
4388 struct btrfs_ioctl_balance_args *bargs;
4389 int ret = 0;
4390
4391 if (!capable(CAP_SYS_ADMIN))
4392 return -EPERM;
4393
4394 mutex_lock(&fs_info->balance_mutex);
4395 if (!fs_info->balance_ctl) {
4396 ret = -ENOTCONN;
4397 goto out;
4398 }
4399
4400 bargs = kzalloc(sizeof(*bargs), GFP_NOFS);
4401 if (!bargs) {
4402 ret = -ENOMEM;
4403 goto out;
4404 }
4405
4406 update_ioctl_balance_args(fs_info, 1, bargs);
4407
4408 if (copy_to_user(arg, bargs, sizeof(*bargs)))
4409 ret = -EFAULT;
4410
4411 kfree(bargs);
4412 out:
4413 mutex_unlock(&fs_info->balance_mutex);
4414 return ret;
4415 }
4416
4417 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4418 {
4419 struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4420 struct btrfs_ioctl_quota_ctl_args *sa;
4421 struct btrfs_trans_handle *trans = NULL;
4422 int ret;
4423 int err;
4424
4425 if (!capable(CAP_SYS_ADMIN))
4426 return -EPERM;
4427
4428 ret = mnt_want_write_file(file);
4429 if (ret)
4430 return ret;
4431
4432 sa = memdup_user(arg, sizeof(*sa));
4433 if (IS_ERR(sa)) {
4434 ret = PTR_ERR(sa);
4435 goto drop_write;
4436 }
4437
4438 down_write(&root->fs_info->subvol_sem);
4439 trans = btrfs_start_transaction(root->fs_info->tree_root, 2);
4440 if (IS_ERR(trans)) {
4441 ret = PTR_ERR(trans);
4442 goto out;
4443 }
4444
4445 switch (sa->cmd) {
4446 case BTRFS_QUOTA_CTL_ENABLE:
4447 ret = btrfs_quota_enable(trans, root->fs_info);
4448 break;
4449 case BTRFS_QUOTA_CTL_DISABLE:
4450 ret = btrfs_quota_disable(trans, root->fs_info);
4451 break;
4452 default:
4453 ret = -EINVAL;
4454 break;
4455 }
4456
4457 err = btrfs_commit_transaction(trans, root->fs_info->tree_root);
4458 if (err && !ret)
4459 ret = err;
4460 out:
4461 kfree(sa);
4462 up_write(&root->fs_info->subvol_sem);
4463 drop_write:
4464 mnt_drop_write_file(file);
4465 return ret;
4466 }
4467
4468 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4469 {
4470 struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4471 struct btrfs_ioctl_qgroup_assign_args *sa;
4472 struct btrfs_trans_handle *trans;
4473 int ret;
4474 int err;
4475
4476 if (!capable(CAP_SYS_ADMIN))
4477 return -EPERM;
4478
4479 ret = mnt_want_write_file(file);
4480 if (ret)
4481 return ret;
4482
4483 sa = memdup_user(arg, sizeof(*sa));
4484 if (IS_ERR(sa)) {
4485 ret = PTR_ERR(sa);
4486 goto drop_write;
4487 }
4488
4489 trans = btrfs_join_transaction(root);
4490 if (IS_ERR(trans)) {
4491 ret = PTR_ERR(trans);
4492 goto out;
4493 }
4494
4495 /* FIXME: check if the IDs really exist */
4496 if (sa->assign) {
4497 ret = btrfs_add_qgroup_relation(trans, root->fs_info,
4498 sa->src, sa->dst);
4499 } else {
4500 ret = btrfs_del_qgroup_relation(trans, root->fs_info,
4501 sa->src, sa->dst);
4502 }
4503
4504 err = btrfs_end_transaction(trans, root);
4505 if (err && !ret)
4506 ret = err;
4507
4508 out:
4509 kfree(sa);
4510 drop_write:
4511 mnt_drop_write_file(file);
4512 return ret;
4513 }
4514
4515 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4516 {
4517 struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4518 struct btrfs_ioctl_qgroup_create_args *sa;
4519 struct btrfs_trans_handle *trans;
4520 int ret;
4521 int err;
4522
4523 if (!capable(CAP_SYS_ADMIN))
4524 return -EPERM;
4525
4526 ret = mnt_want_write_file(file);
4527 if (ret)
4528 return ret;
4529
4530 sa = memdup_user(arg, sizeof(*sa));
4531 if (IS_ERR(sa)) {
4532 ret = PTR_ERR(sa);
4533 goto drop_write;
4534 }
4535
4536 if (!sa->qgroupid) {
4537 ret = -EINVAL;
4538 goto out;
4539 }
4540
4541 trans = btrfs_join_transaction(root);
4542 if (IS_ERR(trans)) {
4543 ret = PTR_ERR(trans);
4544 goto out;
4545 }
4546
4547 /* FIXME: check if the IDs really exist */
4548 if (sa->create) {
4549 ret = btrfs_create_qgroup(trans, root->fs_info, sa->qgroupid,
4550 NULL);
4551 } else {
4552 ret = btrfs_remove_qgroup(trans, root->fs_info, sa->qgroupid);
4553 }
4554
4555 err = btrfs_end_transaction(trans, root);
4556 if (err && !ret)
4557 ret = err;
4558
4559 out:
4560 kfree(sa);
4561 drop_write:
4562 mnt_drop_write_file(file);
4563 return ret;
4564 }
4565
4566 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4567 {
4568 struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4569 struct btrfs_ioctl_qgroup_limit_args *sa;
4570 struct btrfs_trans_handle *trans;
4571 int ret;
4572 int err;
4573 u64 qgroupid;
4574
4575 if (!capable(CAP_SYS_ADMIN))
4576 return -EPERM;
4577
4578 ret = mnt_want_write_file(file);
4579 if (ret)
4580 return ret;
4581
4582 sa = memdup_user(arg, sizeof(*sa));
4583 if (IS_ERR(sa)) {
4584 ret = PTR_ERR(sa);
4585 goto drop_write;
4586 }
4587
4588 trans = btrfs_join_transaction(root);
4589 if (IS_ERR(trans)) {
4590 ret = PTR_ERR(trans);
4591 goto out;
4592 }
4593
4594 qgroupid = sa->qgroupid;
4595 if (!qgroupid) {
4596 /* take the current subvol as qgroup */
4597 qgroupid = root->root_key.objectid;
4598 }
4599
4600 /* FIXME: check if the IDs really exist */
4601 ret = btrfs_limit_qgroup(trans, root->fs_info, qgroupid, &sa->lim);
4602
4603 err = btrfs_end_transaction(trans, root);
4604 if (err && !ret)
4605 ret = err;
4606
4607 out:
4608 kfree(sa);
4609 drop_write:
4610 mnt_drop_write_file(file);
4611 return ret;
4612 }
4613
4614 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
4615 {
4616 struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4617 struct btrfs_ioctl_quota_rescan_args *qsa;
4618 int ret;
4619
4620 if (!capable(CAP_SYS_ADMIN))
4621 return -EPERM;
4622
4623 ret = mnt_want_write_file(file);
4624 if (ret)
4625 return ret;
4626
4627 qsa = memdup_user(arg, sizeof(*qsa));
4628 if (IS_ERR(qsa)) {
4629 ret = PTR_ERR(qsa);
4630 goto drop_write;
4631 }
4632
4633 if (qsa->flags) {
4634 ret = -EINVAL;
4635 goto out;
4636 }
4637
4638 ret = btrfs_qgroup_rescan(root->fs_info);
4639
4640 out:
4641 kfree(qsa);
4642 drop_write:
4643 mnt_drop_write_file(file);
4644 return ret;
4645 }
4646
4647 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
4648 {
4649 struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4650 struct btrfs_ioctl_quota_rescan_args *qsa;
4651 int ret = 0;
4652
4653 if (!capable(CAP_SYS_ADMIN))
4654 return -EPERM;
4655
4656 qsa = kzalloc(sizeof(*qsa), GFP_NOFS);
4657 if (!qsa)
4658 return -ENOMEM;
4659
4660 if (root->fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
4661 qsa->flags = 1;
4662 qsa->progress = root->fs_info->qgroup_rescan_progress.objectid;
4663 }
4664
4665 if (copy_to_user(arg, qsa, sizeof(*qsa)))
4666 ret = -EFAULT;
4667
4668 kfree(qsa);
4669 return ret;
4670 }
4671
4672 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
4673 {
4674 struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4675
4676 if (!capable(CAP_SYS_ADMIN))
4677 return -EPERM;
4678
4679 return btrfs_qgroup_wait_for_completion(root->fs_info);
4680 }
4681
4682 static long _btrfs_ioctl_set_received_subvol(struct file *file,
4683 struct btrfs_ioctl_received_subvol_args *sa)
4684 {
4685 struct inode *inode = file_inode(file);
4686 struct btrfs_root *root = BTRFS_I(inode)->root;
4687 struct btrfs_root_item *root_item = &root->root_item;
4688 struct btrfs_trans_handle *trans;
4689 struct timespec ct = CURRENT_TIME;
4690 int ret = 0;
4691 int received_uuid_changed;
4692
4693 if (!inode_owner_or_capable(inode))
4694 return -EPERM;
4695
4696 ret = mnt_want_write_file(file);
4697 if (ret < 0)
4698 return ret;
4699
4700 down_write(&root->fs_info->subvol_sem);
4701
4702 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
4703 ret = -EINVAL;
4704 goto out;
4705 }
4706
4707 if (btrfs_root_readonly(root)) {
4708 ret = -EROFS;
4709 goto out;
4710 }
4711
4712 /*
4713 * 1 - root item
4714 * 2 - uuid items (received uuid + subvol uuid)
4715 */
4716 trans = btrfs_start_transaction(root, 3);
4717 if (IS_ERR(trans)) {
4718 ret = PTR_ERR(trans);
4719 trans = NULL;
4720 goto out;
4721 }
4722
4723 sa->rtransid = trans->transid;
4724 sa->rtime.sec = ct.tv_sec;
4725 sa->rtime.nsec = ct.tv_nsec;
4726
4727 received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
4728 BTRFS_UUID_SIZE);
4729 if (received_uuid_changed &&
4730 !btrfs_is_empty_uuid(root_item->received_uuid))
4731 btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root,
4732 root_item->received_uuid,
4733 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4734 root->root_key.objectid);
4735 memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
4736 btrfs_set_root_stransid(root_item, sa->stransid);
4737 btrfs_set_root_rtransid(root_item, sa->rtransid);
4738 btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
4739 btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
4740 btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
4741 btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
4742
4743 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4744 &root->root_key, &root->root_item);
4745 if (ret < 0) {
4746 btrfs_end_transaction(trans, root);
4747 goto out;
4748 }
4749 if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
4750 ret = btrfs_uuid_tree_add(trans, root->fs_info->uuid_root,
4751 sa->uuid,
4752 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4753 root->root_key.objectid);
4754 if (ret < 0 && ret != -EEXIST) {
4755 btrfs_abort_transaction(trans, root, ret);
4756 goto out;
4757 }
4758 }
4759 ret = btrfs_commit_transaction(trans, root);
4760 if (ret < 0) {
4761 btrfs_abort_transaction(trans, root, ret);
4762 goto out;
4763 }
4764
4765 out:
4766 up_write(&root->fs_info->subvol_sem);
4767 mnt_drop_write_file(file);
4768 return ret;
4769 }
4770
4771 #ifdef CONFIG_64BIT
4772 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
4773 void __user *arg)
4774 {
4775 struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
4776 struct btrfs_ioctl_received_subvol_args *args64 = NULL;
4777 int ret = 0;
4778
4779 args32 = memdup_user(arg, sizeof(*args32));
4780 if (IS_ERR(args32)) {
4781 ret = PTR_ERR(args32);
4782 args32 = NULL;
4783 goto out;
4784 }
4785
4786 args64 = kmalloc(sizeof(*args64), GFP_NOFS);
4787 if (!args64) {
4788 ret = -ENOMEM;
4789 goto out;
4790 }
4791
4792 memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
4793 args64->stransid = args32->stransid;
4794 args64->rtransid = args32->rtransid;
4795 args64->stime.sec = args32->stime.sec;
4796 args64->stime.nsec = args32->stime.nsec;
4797 args64->rtime.sec = args32->rtime.sec;
4798 args64->rtime.nsec = args32->rtime.nsec;
4799 args64->flags = args32->flags;
4800
4801 ret = _btrfs_ioctl_set_received_subvol(file, args64);
4802 if (ret)
4803 goto out;
4804
4805 memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
4806 args32->stransid = args64->stransid;
4807 args32->rtransid = args64->rtransid;
4808 args32->stime.sec = args64->stime.sec;
4809 args32->stime.nsec = args64->stime.nsec;
4810 args32->rtime.sec = args64->rtime.sec;
4811 args32->rtime.nsec = args64->rtime.nsec;
4812 args32->flags = args64->flags;
4813
4814 ret = copy_to_user(arg, args32, sizeof(*args32));
4815 if (ret)
4816 ret = -EFAULT;
4817
4818 out:
4819 kfree(args32);
4820 kfree(args64);
4821 return ret;
4822 }
4823 #endif
4824
4825 static long btrfs_ioctl_set_received_subvol(struct file *file,
4826 void __user *arg)
4827 {
4828 struct btrfs_ioctl_received_subvol_args *sa = NULL;
4829 int ret = 0;
4830
4831 sa = memdup_user(arg, sizeof(*sa));
4832 if (IS_ERR(sa)) {
4833 ret = PTR_ERR(sa);
4834 sa = NULL;
4835 goto out;
4836 }
4837
4838 ret = _btrfs_ioctl_set_received_subvol(file, sa);
4839
4840 if (ret)
4841 goto out;
4842
4843 ret = copy_to_user(arg, sa, sizeof(*sa));
4844 if (ret)
4845 ret = -EFAULT;
4846
4847 out:
4848 kfree(sa);
4849 return ret;
4850 }
4851
4852 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
4853 {
4854 struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4855 size_t len;
4856 int ret;
4857 char label[BTRFS_LABEL_SIZE];
4858
4859 spin_lock(&root->fs_info->super_lock);
4860 memcpy(label, root->fs_info->super_copy->label, BTRFS_LABEL_SIZE);
4861 spin_unlock(&root->fs_info->super_lock);
4862
4863 len = strnlen(label, BTRFS_LABEL_SIZE);
4864
4865 if (len == BTRFS_LABEL_SIZE) {
4866 btrfs_warn(root->fs_info,
4867 "label is too long, return the first %zu bytes", --len);
4868 }
4869
4870 ret = copy_to_user(arg, label, len);
4871
4872 return ret ? -EFAULT : 0;
4873 }
4874
4875 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
4876 {
4877 struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4878 struct btrfs_super_block *super_block = root->fs_info->super_copy;
4879 struct btrfs_trans_handle *trans;
4880 char label[BTRFS_LABEL_SIZE];
4881 int ret;
4882
4883 if (!capable(CAP_SYS_ADMIN))
4884 return -EPERM;
4885
4886 if (copy_from_user(label, arg, sizeof(label)))
4887 return -EFAULT;
4888
4889 if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
4890 btrfs_err(root->fs_info, "unable to set label with more than %d bytes",
4891 BTRFS_LABEL_SIZE - 1);
4892 return -EINVAL;
4893 }
4894
4895 ret = mnt_want_write_file(file);
4896 if (ret)
4897 return ret;
4898
4899 trans = btrfs_start_transaction(root, 0);
4900 if (IS_ERR(trans)) {
4901 ret = PTR_ERR(trans);
4902 goto out_unlock;
4903 }
4904
4905 spin_lock(&root->fs_info->super_lock);
4906 strcpy(super_block->label, label);
4907 spin_unlock(&root->fs_info->super_lock);
4908 ret = btrfs_commit_transaction(trans, root);
4909
4910 out_unlock:
4911 mnt_drop_write_file(file);
4912 return ret;
4913 }
4914
4915 #define INIT_FEATURE_FLAGS(suffix) \
4916 { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
4917 .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
4918 .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
4919
4920 static int btrfs_ioctl_get_supported_features(struct file *file,
4921 void __user *arg)
4922 {
4923 static struct btrfs_ioctl_feature_flags features[3] = {
4924 INIT_FEATURE_FLAGS(SUPP),
4925 INIT_FEATURE_FLAGS(SAFE_SET),
4926 INIT_FEATURE_FLAGS(SAFE_CLEAR)
4927 };
4928
4929 if (copy_to_user(arg, &features, sizeof(features)))
4930 return -EFAULT;
4931
4932 return 0;
4933 }
4934
4935 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
4936 {
4937 struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4938 struct btrfs_super_block *super_block = root->fs_info->super_copy;
4939 struct btrfs_ioctl_feature_flags features;
4940
4941 features.compat_flags = btrfs_super_compat_flags(super_block);
4942 features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
4943 features.incompat_flags = btrfs_super_incompat_flags(super_block);
4944
4945 if (copy_to_user(arg, &features, sizeof(features)))
4946 return -EFAULT;
4947
4948 return 0;
4949 }
4950
4951 static int check_feature_bits(struct btrfs_root *root,
4952 enum btrfs_feature_set set,
4953 u64 change_mask, u64 flags, u64 supported_flags,
4954 u64 safe_set, u64 safe_clear)
4955 {
4956 const char *type = btrfs_feature_set_names[set];
4957 char *names;
4958 u64 disallowed, unsupported;
4959 u64 set_mask = flags & change_mask;
4960 u64 clear_mask = ~flags & change_mask;
4961
4962 unsupported = set_mask & ~supported_flags;
4963 if (unsupported) {
4964 names = btrfs_printable_features(set, unsupported);
4965 if (names) {
4966 btrfs_warn(root->fs_info,
4967 "this kernel does not support the %s feature bit%s",
4968 names, strchr(names, ',') ? "s" : "");
4969 kfree(names);
4970 } else
4971 btrfs_warn(root->fs_info,
4972 "this kernel does not support %s bits 0x%llx",
4973 type, unsupported);
4974 return -EOPNOTSUPP;
4975 }
4976
4977 disallowed = set_mask & ~safe_set;
4978 if (disallowed) {
4979 names = btrfs_printable_features(set, disallowed);
4980 if (names) {
4981 btrfs_warn(root->fs_info,
4982 "can't set the %s feature bit%s while mounted",
4983 names, strchr(names, ',') ? "s" : "");
4984 kfree(names);
4985 } else
4986 btrfs_warn(root->fs_info,
4987 "can't set %s bits 0x%llx while mounted",
4988 type, disallowed);
4989 return -EPERM;
4990 }
4991
4992 disallowed = clear_mask & ~safe_clear;
4993 if (disallowed) {
4994 names = btrfs_printable_features(set, disallowed);
4995 if (names) {
4996 btrfs_warn(root->fs_info,
4997 "can't clear the %s feature bit%s while mounted",
4998 names, strchr(names, ',') ? "s" : "");
4999 kfree(names);
5000 } else
5001 btrfs_warn(root->fs_info,
5002 "can't clear %s bits 0x%llx while mounted",
5003 type, disallowed);
5004 return -EPERM;
5005 }
5006
5007 return 0;
5008 }
5009
5010 #define check_feature(root, change_mask, flags, mask_base) \
5011 check_feature_bits(root, FEAT_##mask_base, change_mask, flags, \
5012 BTRFS_FEATURE_ ## mask_base ## _SUPP, \
5013 BTRFS_FEATURE_ ## mask_base ## _SAFE_SET, \
5014 BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5015
5016 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5017 {
5018 struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5019 struct btrfs_super_block *super_block = root->fs_info->super_copy;
5020 struct btrfs_ioctl_feature_flags flags[2];
5021 struct btrfs_trans_handle *trans;
5022 u64 newflags;
5023 int ret;
5024
5025 if (!capable(CAP_SYS_ADMIN))
5026 return -EPERM;
5027
5028 if (copy_from_user(flags, arg, sizeof(flags)))
5029 return -EFAULT;
5030
5031 /* Nothing to do */
5032 if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5033 !flags[0].incompat_flags)
5034 return 0;
5035
5036 ret = check_feature(root, flags[0].compat_flags,
5037 flags[1].compat_flags, COMPAT);
5038 if (ret)
5039 return ret;
5040
5041 ret = check_feature(root, flags[0].compat_ro_flags,
5042 flags[1].compat_ro_flags, COMPAT_RO);
5043 if (ret)
5044 return ret;
5045
5046 ret = check_feature(root, flags[0].incompat_flags,
5047 flags[1].incompat_flags, INCOMPAT);
5048 if (ret)
5049 return ret;
5050
5051 trans = btrfs_start_transaction(root, 0);
5052 if (IS_ERR(trans))
5053 return PTR_ERR(trans);
5054
5055 spin_lock(&root->fs_info->super_lock);
5056 newflags = btrfs_super_compat_flags(super_block);
5057 newflags |= flags[0].compat_flags & flags[1].compat_flags;
5058 newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5059 btrfs_set_super_compat_flags(super_block, newflags);
5060
5061 newflags = btrfs_super_compat_ro_flags(super_block);
5062 newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5063 newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5064 btrfs_set_super_compat_ro_flags(super_block, newflags);
5065
5066 newflags = btrfs_super_incompat_flags(super_block);
5067 newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5068 newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5069 btrfs_set_super_incompat_flags(super_block, newflags);
5070 spin_unlock(&root->fs_info->super_lock);
5071
5072 return btrfs_commit_transaction(trans, root);
5073 }
5074
5075 long btrfs_ioctl(struct file *file, unsigned int
5076 cmd, unsigned long arg)
5077 {
5078 struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5079 void __user *argp = (void __user *)arg;
5080
5081 switch (cmd) {
5082 case FS_IOC_GETFLAGS:
5083 return btrfs_ioctl_getflags(file, argp);
5084 case FS_IOC_SETFLAGS:
5085 return btrfs_ioctl_setflags(file, argp);
5086 case FS_IOC_GETVERSION:
5087 return btrfs_ioctl_getversion(file, argp);
5088 case FITRIM:
5089 return btrfs_ioctl_fitrim(file, argp);
5090 case BTRFS_IOC_SNAP_CREATE:
5091 return btrfs_ioctl_snap_create(file, argp, 0);
5092 case BTRFS_IOC_SNAP_CREATE_V2:
5093 return btrfs_ioctl_snap_create_v2(file, argp, 0);
5094 case BTRFS_IOC_SUBVOL_CREATE:
5095 return btrfs_ioctl_snap_create(file, argp, 1);
5096 case BTRFS_IOC_SUBVOL_CREATE_V2:
5097 return btrfs_ioctl_snap_create_v2(file, argp, 1);
5098 case BTRFS_IOC_SNAP_DESTROY:
5099 return btrfs_ioctl_snap_destroy(file, argp);
5100 case BTRFS_IOC_SUBVOL_GETFLAGS:
5101 return btrfs_ioctl_subvol_getflags(file, argp);
5102 case BTRFS_IOC_SUBVOL_SETFLAGS:
5103 return btrfs_ioctl_subvol_setflags(file, argp);
5104 case BTRFS_IOC_DEFAULT_SUBVOL:
5105 return btrfs_ioctl_default_subvol(file, argp);
5106 case BTRFS_IOC_DEFRAG:
5107 return btrfs_ioctl_defrag(file, NULL);
5108 case BTRFS_IOC_DEFRAG_RANGE:
5109 return btrfs_ioctl_defrag(file, argp);
5110 case BTRFS_IOC_RESIZE:
5111 return btrfs_ioctl_resize(file, argp);
5112 case BTRFS_IOC_ADD_DEV:
5113 return btrfs_ioctl_add_dev(root, argp);
5114 case BTRFS_IOC_RM_DEV:
5115 return btrfs_ioctl_rm_dev(file, argp);
5116 case BTRFS_IOC_FS_INFO:
5117 return btrfs_ioctl_fs_info(root, argp);
5118 case BTRFS_IOC_DEV_INFO:
5119 return btrfs_ioctl_dev_info(root, argp);
5120 case BTRFS_IOC_BALANCE:
5121 return btrfs_ioctl_balance(file, NULL);
5122 case BTRFS_IOC_CLONE:
5123 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
5124 case BTRFS_IOC_CLONE_RANGE:
5125 return btrfs_ioctl_clone_range(file, argp);
5126 case BTRFS_IOC_TRANS_START:
5127 return btrfs_ioctl_trans_start(file);
5128 case BTRFS_IOC_TRANS_END:
5129 return btrfs_ioctl_trans_end(file);
5130 case BTRFS_IOC_TREE_SEARCH:
5131 return btrfs_ioctl_tree_search(file, argp);
5132 case BTRFS_IOC_INO_LOOKUP:
5133 return btrfs_ioctl_ino_lookup(file, argp);
5134 case BTRFS_IOC_INO_PATHS:
5135 return btrfs_ioctl_ino_to_path(root, argp);
5136 case BTRFS_IOC_LOGICAL_INO:
5137 return btrfs_ioctl_logical_to_ino(root, argp);
5138 case BTRFS_IOC_SPACE_INFO:
5139 return btrfs_ioctl_space_info(root, argp);
5140 case BTRFS_IOC_SYNC: {
5141 int ret;
5142
5143 ret = btrfs_start_delalloc_roots(root->fs_info, 0, -1);
5144 if (ret)
5145 return ret;
5146 ret = btrfs_sync_fs(file->f_dentry->d_sb, 1);
5147 return ret;
5148 }
5149 case BTRFS_IOC_START_SYNC:
5150 return btrfs_ioctl_start_sync(root, argp);
5151 case BTRFS_IOC_WAIT_SYNC:
5152 return btrfs_ioctl_wait_sync(root, argp);
5153 case BTRFS_IOC_SCRUB:
5154 return btrfs_ioctl_scrub(file, argp);
5155 case BTRFS_IOC_SCRUB_CANCEL:
5156 return btrfs_ioctl_scrub_cancel(root, argp);
5157 case BTRFS_IOC_SCRUB_PROGRESS:
5158 return btrfs_ioctl_scrub_progress(root, argp);
5159 case BTRFS_IOC_BALANCE_V2:
5160 return btrfs_ioctl_balance(file, argp);
5161 case BTRFS_IOC_BALANCE_CTL:
5162 return btrfs_ioctl_balance_ctl(root, arg);
5163 case BTRFS_IOC_BALANCE_PROGRESS:
5164 return btrfs_ioctl_balance_progress(root, argp);
5165 case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5166 return btrfs_ioctl_set_received_subvol(file, argp);
5167 #ifdef CONFIG_64BIT
5168 case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5169 return btrfs_ioctl_set_received_subvol_32(file, argp);
5170 #endif
5171 case BTRFS_IOC_SEND:
5172 return btrfs_ioctl_send(file, argp);
5173 case BTRFS_IOC_GET_DEV_STATS:
5174 return btrfs_ioctl_get_dev_stats(root, argp);
5175 case BTRFS_IOC_QUOTA_CTL:
5176 return btrfs_ioctl_quota_ctl(file, argp);
5177 case BTRFS_IOC_QGROUP_ASSIGN:
5178 return btrfs_ioctl_qgroup_assign(file, argp);
5179 case BTRFS_IOC_QGROUP_CREATE:
5180 return btrfs_ioctl_qgroup_create(file, argp);
5181 case BTRFS_IOC_QGROUP_LIMIT:
5182 return btrfs_ioctl_qgroup_limit(file, argp);
5183 case BTRFS_IOC_QUOTA_RESCAN:
5184 return btrfs_ioctl_quota_rescan(file, argp);
5185 case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5186 return btrfs_ioctl_quota_rescan_status(file, argp);
5187 case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5188 return btrfs_ioctl_quota_rescan_wait(file, argp);
5189 case BTRFS_IOC_DEV_REPLACE:
5190 return btrfs_ioctl_dev_replace(root, argp);
5191 case BTRFS_IOC_GET_FSLABEL:
5192 return btrfs_ioctl_get_fslabel(file, argp);
5193 case BTRFS_IOC_SET_FSLABEL:
5194 return btrfs_ioctl_set_fslabel(file, argp);
5195 case BTRFS_IOC_FILE_EXTENT_SAME:
5196 return btrfs_ioctl_file_extent_same(file, argp);
5197 case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5198 return btrfs_ioctl_get_supported_features(file, argp);
5199 case BTRFS_IOC_GET_FEATURES:
5200 return btrfs_ioctl_get_features(file, argp);
5201 case BTRFS_IOC_SET_FEATURES:
5202 return btrfs_ioctl_set_features(file, argp);
5203 }
5204
5205 return -ENOTTY;
5206 }
Linux kernel - Deliverables
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