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[mirror_ubuntu-artful-kernel.git] / fs / btrfs / ioctl.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/fsnotify.h>
25 #include <linux/pagemap.h>
26 #include <linux/highmem.h>
27 #include <linux/time.h>
28 #include <linux/init.h>
29 #include <linux/string.h>
30 #include <linux/backing-dev.h>
31 #include <linux/mount.h>
32 #include <linux/mpage.h>
33 #include <linux/namei.h>
34 #include <linux/swap.h>
35 #include <linux/writeback.h>
36 #include <linux/statfs.h>
37 #include <linux/compat.h>
38 #include <linux/bit_spinlock.h>
39 #include <linux/security.h>
40 #include <linux/xattr.h>
41 #include <linux/vmalloc.h>
42 #include <linux/slab.h>
43 #include "compat.h"
44 #include "ctree.h"
45 #include "disk-io.h"
46 #include "transaction.h"
47 #include "btrfs_inode.h"
48 #include "ioctl.h"
49 #include "print-tree.h"
50 #include "volumes.h"
51 #include "locking.h"
52
53 /* Mask out flags that are inappropriate for the given type of inode. */
54 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
55 {
56 if (S_ISDIR(mode))
57 return flags;
58 else if (S_ISREG(mode))
59 return flags & ~FS_DIRSYNC_FL;
60 else
61 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
62 }
63
64 /*
65 * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
66 */
67 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
68 {
69 unsigned int iflags = 0;
70
71 if (flags & BTRFS_INODE_SYNC)
72 iflags |= FS_SYNC_FL;
73 if (flags & BTRFS_INODE_IMMUTABLE)
74 iflags |= FS_IMMUTABLE_FL;
75 if (flags & BTRFS_INODE_APPEND)
76 iflags |= FS_APPEND_FL;
77 if (flags & BTRFS_INODE_NODUMP)
78 iflags |= FS_NODUMP_FL;
79 if (flags & BTRFS_INODE_NOATIME)
80 iflags |= FS_NOATIME_FL;
81 if (flags & BTRFS_INODE_DIRSYNC)
82 iflags |= FS_DIRSYNC_FL;
83
84 return iflags;
85 }
86
87 /*
88 * Update inode->i_flags based on the btrfs internal flags.
89 */
90 void btrfs_update_iflags(struct inode *inode)
91 {
92 struct btrfs_inode *ip = BTRFS_I(inode);
93
94 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
95
96 if (ip->flags & BTRFS_INODE_SYNC)
97 inode->i_flags |= S_SYNC;
98 if (ip->flags & BTRFS_INODE_IMMUTABLE)
99 inode->i_flags |= S_IMMUTABLE;
100 if (ip->flags & BTRFS_INODE_APPEND)
101 inode->i_flags |= S_APPEND;
102 if (ip->flags & BTRFS_INODE_NOATIME)
103 inode->i_flags |= S_NOATIME;
104 if (ip->flags & BTRFS_INODE_DIRSYNC)
105 inode->i_flags |= S_DIRSYNC;
106 }
107
108 /*
109 * Inherit flags from the parent inode.
110 *
111 * Unlike extN we don't have any flags we don't want to inherit currently.
112 */
113 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
114 {
115 unsigned int flags;
116
117 if (!dir)
118 return;
119
120 flags = BTRFS_I(dir)->flags;
121
122 if (S_ISREG(inode->i_mode))
123 flags &= ~BTRFS_INODE_DIRSYNC;
124 else if (!S_ISDIR(inode->i_mode))
125 flags &= (BTRFS_INODE_NODUMP | BTRFS_INODE_NOATIME);
126
127 BTRFS_I(inode)->flags = flags;
128 btrfs_update_iflags(inode);
129 }
130
131 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
132 {
133 struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode);
134 unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
135
136 if (copy_to_user(arg, &flags, sizeof(flags)))
137 return -EFAULT;
138 return 0;
139 }
140
141 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
142 {
143 struct inode *inode = file->f_path.dentry->d_inode;
144 struct btrfs_inode *ip = BTRFS_I(inode);
145 struct btrfs_root *root = ip->root;
146 struct btrfs_trans_handle *trans;
147 unsigned int flags, oldflags;
148 int ret;
149
150 if (btrfs_root_readonly(root))
151 return -EROFS;
152
153 if (copy_from_user(&flags, arg, sizeof(flags)))
154 return -EFAULT;
155
156 if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
157 FS_NOATIME_FL | FS_NODUMP_FL | \
158 FS_SYNC_FL | FS_DIRSYNC_FL))
159 return -EOPNOTSUPP;
160
161 if (!inode_owner_or_capable(inode))
162 return -EACCES;
163
164 mutex_lock(&inode->i_mutex);
165
166 flags = btrfs_mask_flags(inode->i_mode, flags);
167 oldflags = btrfs_flags_to_ioctl(ip->flags);
168 if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
169 if (!capable(CAP_LINUX_IMMUTABLE)) {
170 ret = -EPERM;
171 goto out_unlock;
172 }
173 }
174
175 ret = mnt_want_write(file->f_path.mnt);
176 if (ret)
177 goto out_unlock;
178
179 if (flags & FS_SYNC_FL)
180 ip->flags |= BTRFS_INODE_SYNC;
181 else
182 ip->flags &= ~BTRFS_INODE_SYNC;
183 if (flags & FS_IMMUTABLE_FL)
184 ip->flags |= BTRFS_INODE_IMMUTABLE;
185 else
186 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
187 if (flags & FS_APPEND_FL)
188 ip->flags |= BTRFS_INODE_APPEND;
189 else
190 ip->flags &= ~BTRFS_INODE_APPEND;
191 if (flags & FS_NODUMP_FL)
192 ip->flags |= BTRFS_INODE_NODUMP;
193 else
194 ip->flags &= ~BTRFS_INODE_NODUMP;
195 if (flags & FS_NOATIME_FL)
196 ip->flags |= BTRFS_INODE_NOATIME;
197 else
198 ip->flags &= ~BTRFS_INODE_NOATIME;
199 if (flags & FS_DIRSYNC_FL)
200 ip->flags |= BTRFS_INODE_DIRSYNC;
201 else
202 ip->flags &= ~BTRFS_INODE_DIRSYNC;
203
204
205 trans = btrfs_join_transaction(root, 1);
206 BUG_ON(IS_ERR(trans));
207
208 ret = btrfs_update_inode(trans, root, inode);
209 BUG_ON(ret);
210
211 btrfs_update_iflags(inode);
212 inode->i_ctime = CURRENT_TIME;
213 btrfs_end_transaction(trans, root);
214
215 mnt_drop_write(file->f_path.mnt);
216 out_unlock:
217 mutex_unlock(&inode->i_mutex);
218 return 0;
219 }
220
221 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
222 {
223 struct inode *inode = file->f_path.dentry->d_inode;
224
225 return put_user(inode->i_generation, arg);
226 }
227
228 static noinline int create_subvol(struct btrfs_root *root,
229 struct dentry *dentry,
230 char *name, int namelen,
231 u64 *async_transid)
232 {
233 struct btrfs_trans_handle *trans;
234 struct btrfs_key key;
235 struct btrfs_root_item root_item;
236 struct btrfs_inode_item *inode_item;
237 struct extent_buffer *leaf;
238 struct btrfs_root *new_root;
239 struct dentry *parent = dget_parent(dentry);
240 struct inode *dir;
241 int ret;
242 int err;
243 u64 objectid;
244 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
245 u64 index = 0;
246
247 ret = btrfs_find_free_objectid(NULL, root->fs_info->tree_root,
248 0, &objectid);
249 if (ret) {
250 dput(parent);
251 return ret;
252 }
253
254 dir = parent->d_inode;
255
256 /*
257 * 1 - inode item
258 * 2 - refs
259 * 1 - root item
260 * 2 - dir items
261 */
262 trans = btrfs_start_transaction(root, 6);
263 if (IS_ERR(trans)) {
264 dput(parent);
265 return PTR_ERR(trans);
266 }
267
268 leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
269 0, objectid, NULL, 0, 0, 0);
270 if (IS_ERR(leaf)) {
271 ret = PTR_ERR(leaf);
272 goto fail;
273 }
274
275 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
276 btrfs_set_header_bytenr(leaf, leaf->start);
277 btrfs_set_header_generation(leaf, trans->transid);
278 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
279 btrfs_set_header_owner(leaf, objectid);
280
281 write_extent_buffer(leaf, root->fs_info->fsid,
282 (unsigned long)btrfs_header_fsid(leaf),
283 BTRFS_FSID_SIZE);
284 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
285 (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
286 BTRFS_UUID_SIZE);
287 btrfs_mark_buffer_dirty(leaf);
288
289 inode_item = &root_item.inode;
290 memset(inode_item, 0, sizeof(*inode_item));
291 inode_item->generation = cpu_to_le64(1);
292 inode_item->size = cpu_to_le64(3);
293 inode_item->nlink = cpu_to_le32(1);
294 inode_item->nbytes = cpu_to_le64(root->leafsize);
295 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
296
297 btrfs_set_root_bytenr(&root_item, leaf->start);
298 btrfs_set_root_generation(&root_item, trans->transid);
299 btrfs_set_root_level(&root_item, 0);
300 btrfs_set_root_refs(&root_item, 1);
301 btrfs_set_root_used(&root_item, leaf->len);
302 btrfs_set_root_last_snapshot(&root_item, 0);
303
304 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
305 root_item.drop_level = 0;
306
307 btrfs_tree_unlock(leaf);
308 free_extent_buffer(leaf);
309 leaf = NULL;
310
311 btrfs_set_root_dirid(&root_item, new_dirid);
312
313 key.objectid = objectid;
314 key.offset = 0;
315 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
316 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
317 &root_item);
318 if (ret)
319 goto fail;
320
321 key.offset = (u64)-1;
322 new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
323 BUG_ON(IS_ERR(new_root));
324
325 btrfs_record_root_in_trans(trans, new_root);
326
327 ret = btrfs_create_subvol_root(trans, new_root, new_dirid,
328 BTRFS_I(dir)->block_group);
329 /*
330 * insert the directory item
331 */
332 ret = btrfs_set_inode_index(dir, &index);
333 BUG_ON(ret);
334
335 ret = btrfs_insert_dir_item(trans, root,
336 name, namelen, dir->i_ino, &key,
337 BTRFS_FT_DIR, index);
338 if (ret)
339 goto fail;
340
341 btrfs_i_size_write(dir, dir->i_size + namelen * 2);
342 ret = btrfs_update_inode(trans, root, dir);
343 BUG_ON(ret);
344
345 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
346 objectid, root->root_key.objectid,
347 dir->i_ino, index, name, namelen);
348
349 BUG_ON(ret);
350
351 d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
352 fail:
353 dput(parent);
354 if (async_transid) {
355 *async_transid = trans->transid;
356 err = btrfs_commit_transaction_async(trans, root, 1);
357 } else {
358 err = btrfs_commit_transaction(trans, root);
359 }
360 if (err && !ret)
361 ret = err;
362 return ret;
363 }
364
365 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
366 char *name, int namelen, u64 *async_transid,
367 bool readonly)
368 {
369 struct inode *inode;
370 struct dentry *parent;
371 struct btrfs_pending_snapshot *pending_snapshot;
372 struct btrfs_trans_handle *trans;
373 int ret;
374
375 if (!root->ref_cows)
376 return -EINVAL;
377
378 pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
379 if (!pending_snapshot)
380 return -ENOMEM;
381
382 btrfs_init_block_rsv(&pending_snapshot->block_rsv);
383 pending_snapshot->dentry = dentry;
384 pending_snapshot->root = root;
385 pending_snapshot->readonly = readonly;
386
387 trans = btrfs_start_transaction(root->fs_info->extent_root, 5);
388 if (IS_ERR(trans)) {
389 ret = PTR_ERR(trans);
390 goto fail;
391 }
392
393 ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
394 BUG_ON(ret);
395
396 list_add(&pending_snapshot->list,
397 &trans->transaction->pending_snapshots);
398 if (async_transid) {
399 *async_transid = trans->transid;
400 ret = btrfs_commit_transaction_async(trans,
401 root->fs_info->extent_root, 1);
402 } else {
403 ret = btrfs_commit_transaction(trans,
404 root->fs_info->extent_root);
405 }
406 BUG_ON(ret);
407
408 ret = pending_snapshot->error;
409 if (ret)
410 goto fail;
411
412 btrfs_orphan_cleanup(pending_snapshot->snap);
413
414 parent = dget_parent(dentry);
415 inode = btrfs_lookup_dentry(parent->d_inode, dentry);
416 dput(parent);
417 if (IS_ERR(inode)) {
418 ret = PTR_ERR(inode);
419 goto fail;
420 }
421 BUG_ON(!inode);
422 d_instantiate(dentry, inode);
423 ret = 0;
424 fail:
425 kfree(pending_snapshot);
426 return ret;
427 }
428
429 /* copy of check_sticky in fs/namei.c()
430 * It's inline, so penalty for filesystems that don't use sticky bit is
431 * minimal.
432 */
433 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode)
434 {
435 uid_t fsuid = current_fsuid();
436
437 if (!(dir->i_mode & S_ISVTX))
438 return 0;
439 if (inode->i_uid == fsuid)
440 return 0;
441 if (dir->i_uid == fsuid)
442 return 0;
443 return !capable(CAP_FOWNER);
444 }
445
446 /* copy of may_delete in fs/namei.c()
447 * Check whether we can remove a link victim from directory dir, check
448 * whether the type of victim is right.
449 * 1. We can't do it if dir is read-only (done in permission())
450 * 2. We should have write and exec permissions on dir
451 * 3. We can't remove anything from append-only dir
452 * 4. We can't do anything with immutable dir (done in permission())
453 * 5. If the sticky bit on dir is set we should either
454 * a. be owner of dir, or
455 * b. be owner of victim, or
456 * c. have CAP_FOWNER capability
457 * 6. If the victim is append-only or immutable we can't do antyhing with
458 * links pointing to it.
459 * 7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
460 * 8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
461 * 9. We can't remove a root or mountpoint.
462 * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
463 * nfs_async_unlink().
464 */
465
466 static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir)
467 {
468 int error;
469
470 if (!victim->d_inode)
471 return -ENOENT;
472
473 BUG_ON(victim->d_parent->d_inode != dir);
474 audit_inode_child(victim, dir);
475
476 error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
477 if (error)
478 return error;
479 if (IS_APPEND(dir))
480 return -EPERM;
481 if (btrfs_check_sticky(dir, victim->d_inode)||
482 IS_APPEND(victim->d_inode)||
483 IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
484 return -EPERM;
485 if (isdir) {
486 if (!S_ISDIR(victim->d_inode->i_mode))
487 return -ENOTDIR;
488 if (IS_ROOT(victim))
489 return -EBUSY;
490 } else if (S_ISDIR(victim->d_inode->i_mode))
491 return -EISDIR;
492 if (IS_DEADDIR(dir))
493 return -ENOENT;
494 if (victim->d_flags & DCACHE_NFSFS_RENAMED)
495 return -EBUSY;
496 return 0;
497 }
498
499 /* copy of may_create in fs/namei.c() */
500 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
501 {
502 if (child->d_inode)
503 return -EEXIST;
504 if (IS_DEADDIR(dir))
505 return -ENOENT;
506 return inode_permission(dir, MAY_WRITE | MAY_EXEC);
507 }
508
509 /*
510 * Create a new subvolume below @parent. This is largely modeled after
511 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
512 * inside this filesystem so it's quite a bit simpler.
513 */
514 static noinline int btrfs_mksubvol(struct path *parent,
515 char *name, int namelen,
516 struct btrfs_root *snap_src,
517 u64 *async_transid, bool readonly)
518 {
519 struct inode *dir = parent->dentry->d_inode;
520 struct dentry *dentry;
521 int error;
522
523 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
524
525 dentry = lookup_one_len(name, parent->dentry, namelen);
526 error = PTR_ERR(dentry);
527 if (IS_ERR(dentry))
528 goto out_unlock;
529
530 error = -EEXIST;
531 if (dentry->d_inode)
532 goto out_dput;
533
534 error = mnt_want_write(parent->mnt);
535 if (error)
536 goto out_dput;
537
538 error = btrfs_may_create(dir, dentry);
539 if (error)
540 goto out_drop_write;
541
542 down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
543
544 if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
545 goto out_up_read;
546
547 if (snap_src) {
548 error = create_snapshot(snap_src, dentry,
549 name, namelen, async_transid, readonly);
550 } else {
551 error = create_subvol(BTRFS_I(dir)->root, dentry,
552 name, namelen, async_transid);
553 }
554 if (!error)
555 fsnotify_mkdir(dir, dentry);
556 out_up_read:
557 up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
558 out_drop_write:
559 mnt_drop_write(parent->mnt);
560 out_dput:
561 dput(dentry);
562 out_unlock:
563 mutex_unlock(&dir->i_mutex);
564 return error;
565 }
566
567 static int should_defrag_range(struct inode *inode, u64 start, u64 len,
568 int thresh, u64 *last_len, u64 *skip,
569 u64 *defrag_end)
570 {
571 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
572 struct extent_map *em = NULL;
573 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
574 int ret = 1;
575
576
577 if (thresh == 0)
578 thresh = 256 * 1024;
579
580 /*
581 * make sure that once we start defragging and extent, we keep on
582 * defragging it
583 */
584 if (start < *defrag_end)
585 return 1;
586
587 *skip = 0;
588
589 /*
590 * hopefully we have this extent in the tree already, try without
591 * the full extent lock
592 */
593 read_lock(&em_tree->lock);
594 em = lookup_extent_mapping(em_tree, start, len);
595 read_unlock(&em_tree->lock);
596
597 if (!em) {
598 /* get the big lock and read metadata off disk */
599 lock_extent(io_tree, start, start + len - 1, GFP_NOFS);
600 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
601 unlock_extent(io_tree, start, start + len - 1, GFP_NOFS);
602
603 if (IS_ERR(em))
604 return 0;
605 }
606
607 /* this will cover holes, and inline extents */
608 if (em->block_start >= EXTENT_MAP_LAST_BYTE)
609 ret = 0;
610
611 /*
612 * we hit a real extent, if it is big don't bother defragging it again
613 */
614 if ((*last_len == 0 || *last_len >= thresh) && em->len >= thresh)
615 ret = 0;
616
617 /*
618 * last_len ends up being a counter of how many bytes we've defragged.
619 * every time we choose not to defrag an extent, we reset *last_len
620 * so that the next tiny extent will force a defrag.
621 *
622 * The end result of this is that tiny extents before a single big
623 * extent will force at least part of that big extent to be defragged.
624 */
625 if (ret) {
626 *last_len += len;
627 *defrag_end = extent_map_end(em);
628 } else {
629 *last_len = 0;
630 *skip = extent_map_end(em);
631 *defrag_end = 0;
632 }
633
634 free_extent_map(em);
635 return ret;
636 }
637
638 static int btrfs_defrag_file(struct file *file,
639 struct btrfs_ioctl_defrag_range_args *range)
640 {
641 struct inode *inode = fdentry(file)->d_inode;
642 struct btrfs_root *root = BTRFS_I(inode)->root;
643 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
644 struct btrfs_ordered_extent *ordered;
645 struct page *page;
646 struct btrfs_super_block *disk_super;
647 unsigned long last_index;
648 unsigned long ra_pages = root->fs_info->bdi.ra_pages;
649 unsigned long total_read = 0;
650 u64 features;
651 u64 page_start;
652 u64 page_end;
653 u64 last_len = 0;
654 u64 skip = 0;
655 u64 defrag_end = 0;
656 unsigned long i;
657 int ret;
658 int compress_type = BTRFS_COMPRESS_ZLIB;
659
660 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
661 if (range->compress_type > BTRFS_COMPRESS_TYPES)
662 return -EINVAL;
663 if (range->compress_type)
664 compress_type = range->compress_type;
665 }
666
667 if (inode->i_size == 0)
668 return 0;
669
670 if (range->start + range->len > range->start) {
671 last_index = min_t(u64, inode->i_size - 1,
672 range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
673 } else {
674 last_index = (inode->i_size - 1) >> PAGE_CACHE_SHIFT;
675 }
676
677 i = range->start >> PAGE_CACHE_SHIFT;
678 while (i <= last_index) {
679 if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
680 PAGE_CACHE_SIZE,
681 range->extent_thresh,
682 &last_len, &skip,
683 &defrag_end)) {
684 unsigned long next;
685 /*
686 * the should_defrag function tells us how much to skip
687 * bump our counter by the suggested amount
688 */
689 next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
690 i = max(i + 1, next);
691 continue;
692 }
693
694 if (total_read % ra_pages == 0) {
695 btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
696 min(last_index, i + ra_pages - 1));
697 }
698 total_read++;
699 mutex_lock(&inode->i_mutex);
700 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
701 BTRFS_I(inode)->force_compress = compress_type;
702
703 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
704 if (ret)
705 goto err_unlock;
706 again:
707 if (inode->i_size == 0 ||
708 i > ((inode->i_size - 1) >> PAGE_CACHE_SHIFT)) {
709 ret = 0;
710 goto err_reservations;
711 }
712
713 page = grab_cache_page(inode->i_mapping, i);
714 if (!page) {
715 ret = -ENOMEM;
716 goto err_reservations;
717 }
718
719 if (!PageUptodate(page)) {
720 btrfs_readpage(NULL, page);
721 lock_page(page);
722 if (!PageUptodate(page)) {
723 unlock_page(page);
724 page_cache_release(page);
725 ret = -EIO;
726 goto err_reservations;
727 }
728 }
729
730 if (page->mapping != inode->i_mapping) {
731 unlock_page(page);
732 page_cache_release(page);
733 goto again;
734 }
735
736 wait_on_page_writeback(page);
737
738 if (PageDirty(page)) {
739 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
740 goto loop_unlock;
741 }
742
743 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
744 page_end = page_start + PAGE_CACHE_SIZE - 1;
745 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
746
747 ordered = btrfs_lookup_ordered_extent(inode, page_start);
748 if (ordered) {
749 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
750 unlock_page(page);
751 page_cache_release(page);
752 btrfs_start_ordered_extent(inode, ordered, 1);
753 btrfs_put_ordered_extent(ordered);
754 goto again;
755 }
756 set_page_extent_mapped(page);
757
758 /*
759 * this makes sure page_mkwrite is called on the
760 * page if it is dirtied again later
761 */
762 clear_page_dirty_for_io(page);
763 clear_extent_bits(&BTRFS_I(inode)->io_tree, page_start,
764 page_end, EXTENT_DIRTY | EXTENT_DELALLOC |
765 EXTENT_DO_ACCOUNTING, GFP_NOFS);
766
767 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
768 ClearPageChecked(page);
769 set_page_dirty(page);
770 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
771
772 loop_unlock:
773 unlock_page(page);
774 page_cache_release(page);
775 mutex_unlock(&inode->i_mutex);
776
777 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
778 i++;
779 }
780
781 if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
782 filemap_flush(inode->i_mapping);
783
784 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
785 /* the filemap_flush will queue IO into the worker threads, but
786 * we have to make sure the IO is actually started and that
787 * ordered extents get created before we return
788 */
789 atomic_inc(&root->fs_info->async_submit_draining);
790 while (atomic_read(&root->fs_info->nr_async_submits) ||
791 atomic_read(&root->fs_info->async_delalloc_pages)) {
792 wait_event(root->fs_info->async_submit_wait,
793 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
794 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
795 }
796 atomic_dec(&root->fs_info->async_submit_draining);
797
798 mutex_lock(&inode->i_mutex);
799 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
800 mutex_unlock(&inode->i_mutex);
801 }
802
803 disk_super = &root->fs_info->super_copy;
804 features = btrfs_super_incompat_flags(disk_super);
805 if (range->compress_type == BTRFS_COMPRESS_LZO) {
806 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
807 btrfs_set_super_incompat_flags(disk_super, features);
808 }
809
810 return 0;
811
812 err_reservations:
813 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
814 err_unlock:
815 mutex_unlock(&inode->i_mutex);
816 return ret;
817 }
818
819 static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
820 void __user *arg)
821 {
822 u64 new_size;
823 u64 old_size;
824 u64 devid = 1;
825 struct btrfs_ioctl_vol_args *vol_args;
826 struct btrfs_trans_handle *trans;
827 struct btrfs_device *device = NULL;
828 char *sizestr;
829 char *devstr = NULL;
830 int ret = 0;
831 int mod = 0;
832
833 if (root->fs_info->sb->s_flags & MS_RDONLY)
834 return -EROFS;
835
836 if (!capable(CAP_SYS_ADMIN))
837 return -EPERM;
838
839 vol_args = memdup_user(arg, sizeof(*vol_args));
840 if (IS_ERR(vol_args))
841 return PTR_ERR(vol_args);
842
843 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
844
845 mutex_lock(&root->fs_info->volume_mutex);
846 sizestr = vol_args->name;
847 devstr = strchr(sizestr, ':');
848 if (devstr) {
849 char *end;
850 sizestr = devstr + 1;
851 *devstr = '\0';
852 devstr = vol_args->name;
853 devid = simple_strtoull(devstr, &end, 10);
854 printk(KERN_INFO "resizing devid %llu\n",
855 (unsigned long long)devid);
856 }
857 device = btrfs_find_device(root, devid, NULL, NULL);
858 if (!device) {
859 printk(KERN_INFO "resizer unable to find device %llu\n",
860 (unsigned long long)devid);
861 ret = -EINVAL;
862 goto out_unlock;
863 }
864 if (!strcmp(sizestr, "max"))
865 new_size = device->bdev->bd_inode->i_size;
866 else {
867 if (sizestr[0] == '-') {
868 mod = -1;
869 sizestr++;
870 } else if (sizestr[0] == '+') {
871 mod = 1;
872 sizestr++;
873 }
874 new_size = memparse(sizestr, NULL);
875 if (new_size == 0) {
876 ret = -EINVAL;
877 goto out_unlock;
878 }
879 }
880
881 old_size = device->total_bytes;
882
883 if (mod < 0) {
884 if (new_size > old_size) {
885 ret = -EINVAL;
886 goto out_unlock;
887 }
888 new_size = old_size - new_size;
889 } else if (mod > 0) {
890 new_size = old_size + new_size;
891 }
892
893 if (new_size < 256 * 1024 * 1024) {
894 ret = -EINVAL;
895 goto out_unlock;
896 }
897 if (new_size > device->bdev->bd_inode->i_size) {
898 ret = -EFBIG;
899 goto out_unlock;
900 }
901
902 do_div(new_size, root->sectorsize);
903 new_size *= root->sectorsize;
904
905 printk(KERN_INFO "new size for %s is %llu\n",
906 device->name, (unsigned long long)new_size);
907
908 if (new_size > old_size) {
909 trans = btrfs_start_transaction(root, 0);
910 if (IS_ERR(trans)) {
911 ret = PTR_ERR(trans);
912 goto out_unlock;
913 }
914 ret = btrfs_grow_device(trans, device, new_size);
915 btrfs_commit_transaction(trans, root);
916 } else {
917 ret = btrfs_shrink_device(device, new_size);
918 }
919
920 out_unlock:
921 mutex_unlock(&root->fs_info->volume_mutex);
922 kfree(vol_args);
923 return ret;
924 }
925
926 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
927 char *name,
928 unsigned long fd,
929 int subvol,
930 u64 *transid,
931 bool readonly)
932 {
933 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
934 struct file *src_file;
935 int namelen;
936 int ret = 0;
937
938 if (root->fs_info->sb->s_flags & MS_RDONLY)
939 return -EROFS;
940
941 namelen = strlen(name);
942 if (strchr(name, '/')) {
943 ret = -EINVAL;
944 goto out;
945 }
946
947 if (subvol) {
948 ret = btrfs_mksubvol(&file->f_path, name, namelen,
949 NULL, transid, readonly);
950 } else {
951 struct inode *src_inode;
952 src_file = fget(fd);
953 if (!src_file) {
954 ret = -EINVAL;
955 goto out;
956 }
957
958 src_inode = src_file->f_path.dentry->d_inode;
959 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
960 printk(KERN_INFO "btrfs: Snapshot src from "
961 "another FS\n");
962 ret = -EINVAL;
963 fput(src_file);
964 goto out;
965 }
966 ret = btrfs_mksubvol(&file->f_path, name, namelen,
967 BTRFS_I(src_inode)->root,
968 transid, readonly);
969 fput(src_file);
970 }
971 out:
972 return ret;
973 }
974
975 static noinline int btrfs_ioctl_snap_create(struct file *file,
976 void __user *arg, int subvol)
977 {
978 struct btrfs_ioctl_vol_args *vol_args;
979 int ret;
980
981 vol_args = memdup_user(arg, sizeof(*vol_args));
982 if (IS_ERR(vol_args))
983 return PTR_ERR(vol_args);
984 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
985
986 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
987 vol_args->fd, subvol,
988 NULL, false);
989
990 kfree(vol_args);
991 return ret;
992 }
993
994 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
995 void __user *arg, int subvol)
996 {
997 struct btrfs_ioctl_vol_args_v2 *vol_args;
998 int ret;
999 u64 transid = 0;
1000 u64 *ptr = NULL;
1001 bool readonly = false;
1002
1003 vol_args = memdup_user(arg, sizeof(*vol_args));
1004 if (IS_ERR(vol_args))
1005 return PTR_ERR(vol_args);
1006 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1007
1008 if (vol_args->flags &
1009 ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY)) {
1010 ret = -EOPNOTSUPP;
1011 goto out;
1012 }
1013
1014 if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1015 ptr = &transid;
1016 if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1017 readonly = true;
1018
1019 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1020 vol_args->fd, subvol,
1021 ptr, readonly);
1022
1023 if (ret == 0 && ptr &&
1024 copy_to_user(arg +
1025 offsetof(struct btrfs_ioctl_vol_args_v2,
1026 transid), ptr, sizeof(*ptr)))
1027 ret = -EFAULT;
1028 out:
1029 kfree(vol_args);
1030 return ret;
1031 }
1032
1033 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1034 void __user *arg)
1035 {
1036 struct inode *inode = fdentry(file)->d_inode;
1037 struct btrfs_root *root = BTRFS_I(inode)->root;
1038 int ret = 0;
1039 u64 flags = 0;
1040
1041 if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID)
1042 return -EINVAL;
1043
1044 down_read(&root->fs_info->subvol_sem);
1045 if (btrfs_root_readonly(root))
1046 flags |= BTRFS_SUBVOL_RDONLY;
1047 up_read(&root->fs_info->subvol_sem);
1048
1049 if (copy_to_user(arg, &flags, sizeof(flags)))
1050 ret = -EFAULT;
1051
1052 return ret;
1053 }
1054
1055 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1056 void __user *arg)
1057 {
1058 struct inode *inode = fdentry(file)->d_inode;
1059 struct btrfs_root *root = BTRFS_I(inode)->root;
1060 struct btrfs_trans_handle *trans;
1061 u64 root_flags;
1062 u64 flags;
1063 int ret = 0;
1064
1065 if (root->fs_info->sb->s_flags & MS_RDONLY)
1066 return -EROFS;
1067
1068 if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID)
1069 return -EINVAL;
1070
1071 if (copy_from_user(&flags, arg, sizeof(flags)))
1072 return -EFAULT;
1073
1074 if (flags & BTRFS_SUBVOL_CREATE_ASYNC)
1075 return -EINVAL;
1076
1077 if (flags & ~BTRFS_SUBVOL_RDONLY)
1078 return -EOPNOTSUPP;
1079
1080 if (!inode_owner_or_capable(inode))
1081 return -EACCES;
1082
1083 down_write(&root->fs_info->subvol_sem);
1084
1085 /* nothing to do */
1086 if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1087 goto out;
1088
1089 root_flags = btrfs_root_flags(&root->root_item);
1090 if (flags & BTRFS_SUBVOL_RDONLY)
1091 btrfs_set_root_flags(&root->root_item,
1092 root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1093 else
1094 btrfs_set_root_flags(&root->root_item,
1095 root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1096
1097 trans = btrfs_start_transaction(root, 1);
1098 if (IS_ERR(trans)) {
1099 ret = PTR_ERR(trans);
1100 goto out_reset;
1101 }
1102
1103 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1104 &root->root_key, &root->root_item);
1105
1106 btrfs_commit_transaction(trans, root);
1107 out_reset:
1108 if (ret)
1109 btrfs_set_root_flags(&root->root_item, root_flags);
1110 out:
1111 up_write(&root->fs_info->subvol_sem);
1112 return ret;
1113 }
1114
1115 /*
1116 * helper to check if the subvolume references other subvolumes
1117 */
1118 static noinline int may_destroy_subvol(struct btrfs_root *root)
1119 {
1120 struct btrfs_path *path;
1121 struct btrfs_key key;
1122 int ret;
1123
1124 path = btrfs_alloc_path();
1125 if (!path)
1126 return -ENOMEM;
1127
1128 key.objectid = root->root_key.objectid;
1129 key.type = BTRFS_ROOT_REF_KEY;
1130 key.offset = (u64)-1;
1131
1132 ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1133 &key, path, 0, 0);
1134 if (ret < 0)
1135 goto out;
1136 BUG_ON(ret == 0);
1137
1138 ret = 0;
1139 if (path->slots[0] > 0) {
1140 path->slots[0]--;
1141 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1142 if (key.objectid == root->root_key.objectid &&
1143 key.type == BTRFS_ROOT_REF_KEY)
1144 ret = -ENOTEMPTY;
1145 }
1146 out:
1147 btrfs_free_path(path);
1148 return ret;
1149 }
1150
1151 static noinline int key_in_sk(struct btrfs_key *key,
1152 struct btrfs_ioctl_search_key *sk)
1153 {
1154 struct btrfs_key test;
1155 int ret;
1156
1157 test.objectid = sk->min_objectid;
1158 test.type = sk->min_type;
1159 test.offset = sk->min_offset;
1160
1161 ret = btrfs_comp_cpu_keys(key, &test);
1162 if (ret < 0)
1163 return 0;
1164
1165 test.objectid = sk->max_objectid;
1166 test.type = sk->max_type;
1167 test.offset = sk->max_offset;
1168
1169 ret = btrfs_comp_cpu_keys(key, &test);
1170 if (ret > 0)
1171 return 0;
1172 return 1;
1173 }
1174
1175 static noinline int copy_to_sk(struct btrfs_root *root,
1176 struct btrfs_path *path,
1177 struct btrfs_key *key,
1178 struct btrfs_ioctl_search_key *sk,
1179 char *buf,
1180 unsigned long *sk_offset,
1181 int *num_found)
1182 {
1183 u64 found_transid;
1184 struct extent_buffer *leaf;
1185 struct btrfs_ioctl_search_header sh;
1186 unsigned long item_off;
1187 unsigned long item_len;
1188 int nritems;
1189 int i;
1190 int slot;
1191 int found = 0;
1192 int ret = 0;
1193
1194 leaf = path->nodes[0];
1195 slot = path->slots[0];
1196 nritems = btrfs_header_nritems(leaf);
1197
1198 if (btrfs_header_generation(leaf) > sk->max_transid) {
1199 i = nritems;
1200 goto advance_key;
1201 }
1202 found_transid = btrfs_header_generation(leaf);
1203
1204 for (i = slot; i < nritems; i++) {
1205 item_off = btrfs_item_ptr_offset(leaf, i);
1206 item_len = btrfs_item_size_nr(leaf, i);
1207
1208 if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1209 item_len = 0;
1210
1211 if (sizeof(sh) + item_len + *sk_offset >
1212 BTRFS_SEARCH_ARGS_BUFSIZE) {
1213 ret = 1;
1214 goto overflow;
1215 }
1216
1217 btrfs_item_key_to_cpu(leaf, key, i);
1218 if (!key_in_sk(key, sk))
1219 continue;
1220
1221 sh.objectid = key->objectid;
1222 sh.offset = key->offset;
1223 sh.type = key->type;
1224 sh.len = item_len;
1225 sh.transid = found_transid;
1226
1227 /* copy search result header */
1228 memcpy(buf + *sk_offset, &sh, sizeof(sh));
1229 *sk_offset += sizeof(sh);
1230
1231 if (item_len) {
1232 char *p = buf + *sk_offset;
1233 /* copy the item */
1234 read_extent_buffer(leaf, p,
1235 item_off, item_len);
1236 *sk_offset += item_len;
1237 }
1238 found++;
1239
1240 if (*num_found >= sk->nr_items)
1241 break;
1242 }
1243 advance_key:
1244 ret = 0;
1245 if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1246 key->offset++;
1247 else if (key->type < (u8)-1 && key->type < sk->max_type) {
1248 key->offset = 0;
1249 key->type++;
1250 } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1251 key->offset = 0;
1252 key->type = 0;
1253 key->objectid++;
1254 } else
1255 ret = 1;
1256 overflow:
1257 *num_found += found;
1258 return ret;
1259 }
1260
1261 static noinline int search_ioctl(struct inode *inode,
1262 struct btrfs_ioctl_search_args *args)
1263 {
1264 struct btrfs_root *root;
1265 struct btrfs_key key;
1266 struct btrfs_key max_key;
1267 struct btrfs_path *path;
1268 struct btrfs_ioctl_search_key *sk = &args->key;
1269 struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1270 int ret;
1271 int num_found = 0;
1272 unsigned long sk_offset = 0;
1273
1274 path = btrfs_alloc_path();
1275 if (!path)
1276 return -ENOMEM;
1277
1278 if (sk->tree_id == 0) {
1279 /* search the root of the inode that was passed */
1280 root = BTRFS_I(inode)->root;
1281 } else {
1282 key.objectid = sk->tree_id;
1283 key.type = BTRFS_ROOT_ITEM_KEY;
1284 key.offset = (u64)-1;
1285 root = btrfs_read_fs_root_no_name(info, &key);
1286 if (IS_ERR(root)) {
1287 printk(KERN_ERR "could not find root %llu\n",
1288 sk->tree_id);
1289 btrfs_free_path(path);
1290 return -ENOENT;
1291 }
1292 }
1293
1294 key.objectid = sk->min_objectid;
1295 key.type = sk->min_type;
1296 key.offset = sk->min_offset;
1297
1298 max_key.objectid = sk->max_objectid;
1299 max_key.type = sk->max_type;
1300 max_key.offset = sk->max_offset;
1301
1302 path->keep_locks = 1;
1303
1304 while(1) {
1305 ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1306 sk->min_transid);
1307 if (ret != 0) {
1308 if (ret > 0)
1309 ret = 0;
1310 goto err;
1311 }
1312 ret = copy_to_sk(root, path, &key, sk, args->buf,
1313 &sk_offset, &num_found);
1314 btrfs_release_path(root, path);
1315 if (ret || num_found >= sk->nr_items)
1316 break;
1317
1318 }
1319 ret = 0;
1320 err:
1321 sk->nr_items = num_found;
1322 btrfs_free_path(path);
1323 return ret;
1324 }
1325
1326 static noinline int btrfs_ioctl_tree_search(struct file *file,
1327 void __user *argp)
1328 {
1329 struct btrfs_ioctl_search_args *args;
1330 struct inode *inode;
1331 int ret;
1332
1333 if (!capable(CAP_SYS_ADMIN))
1334 return -EPERM;
1335
1336 args = memdup_user(argp, sizeof(*args));
1337 if (IS_ERR(args))
1338 return PTR_ERR(args);
1339
1340 inode = fdentry(file)->d_inode;
1341 ret = search_ioctl(inode, args);
1342 if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1343 ret = -EFAULT;
1344 kfree(args);
1345 return ret;
1346 }
1347
1348 /*
1349 * Search INODE_REFs to identify path name of 'dirid' directory
1350 * in a 'tree_id' tree. and sets path name to 'name'.
1351 */
1352 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1353 u64 tree_id, u64 dirid, char *name)
1354 {
1355 struct btrfs_root *root;
1356 struct btrfs_key key;
1357 char *ptr;
1358 int ret = -1;
1359 int slot;
1360 int len;
1361 int total_len = 0;
1362 struct btrfs_inode_ref *iref;
1363 struct extent_buffer *l;
1364 struct btrfs_path *path;
1365
1366 if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1367 name[0]='\0';
1368 return 0;
1369 }
1370
1371 path = btrfs_alloc_path();
1372 if (!path)
1373 return -ENOMEM;
1374
1375 ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1376
1377 key.objectid = tree_id;
1378 key.type = BTRFS_ROOT_ITEM_KEY;
1379 key.offset = (u64)-1;
1380 root = btrfs_read_fs_root_no_name(info, &key);
1381 if (IS_ERR(root)) {
1382 printk(KERN_ERR "could not find root %llu\n", tree_id);
1383 ret = -ENOENT;
1384 goto out;
1385 }
1386
1387 key.objectid = dirid;
1388 key.type = BTRFS_INODE_REF_KEY;
1389 key.offset = (u64)-1;
1390
1391 while(1) {
1392 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1393 if (ret < 0)
1394 goto out;
1395
1396 l = path->nodes[0];
1397 slot = path->slots[0];
1398 if (ret > 0 && slot > 0)
1399 slot--;
1400 btrfs_item_key_to_cpu(l, &key, slot);
1401
1402 if (ret > 0 && (key.objectid != dirid ||
1403 key.type != BTRFS_INODE_REF_KEY)) {
1404 ret = -ENOENT;
1405 goto out;
1406 }
1407
1408 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1409 len = btrfs_inode_ref_name_len(l, iref);
1410 ptr -= len + 1;
1411 total_len += len + 1;
1412 if (ptr < name)
1413 goto out;
1414
1415 *(ptr + len) = '/';
1416 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1417
1418 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1419 break;
1420
1421 btrfs_release_path(root, path);
1422 key.objectid = key.offset;
1423 key.offset = (u64)-1;
1424 dirid = key.objectid;
1425
1426 }
1427 if (ptr < name)
1428 goto out;
1429 memcpy(name, ptr, total_len);
1430 name[total_len]='\0';
1431 ret = 0;
1432 out:
1433 btrfs_free_path(path);
1434 return ret;
1435 }
1436
1437 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1438 void __user *argp)
1439 {
1440 struct btrfs_ioctl_ino_lookup_args *args;
1441 struct inode *inode;
1442 int ret;
1443
1444 if (!capable(CAP_SYS_ADMIN))
1445 return -EPERM;
1446
1447 args = memdup_user(argp, sizeof(*args));
1448 if (IS_ERR(args))
1449 return PTR_ERR(args);
1450
1451 inode = fdentry(file)->d_inode;
1452
1453 if (args->treeid == 0)
1454 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
1455
1456 ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
1457 args->treeid, args->objectid,
1458 args->name);
1459
1460 if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1461 ret = -EFAULT;
1462
1463 kfree(args);
1464 return ret;
1465 }
1466
1467 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
1468 void __user *arg)
1469 {
1470 struct dentry *parent = fdentry(file);
1471 struct dentry *dentry;
1472 struct inode *dir = parent->d_inode;
1473 struct inode *inode;
1474 struct btrfs_root *root = BTRFS_I(dir)->root;
1475 struct btrfs_root *dest = NULL;
1476 struct btrfs_ioctl_vol_args *vol_args;
1477 struct btrfs_trans_handle *trans;
1478 int namelen;
1479 int ret;
1480 int err = 0;
1481
1482 vol_args = memdup_user(arg, sizeof(*vol_args));
1483 if (IS_ERR(vol_args))
1484 return PTR_ERR(vol_args);
1485
1486 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1487 namelen = strlen(vol_args->name);
1488 if (strchr(vol_args->name, '/') ||
1489 strncmp(vol_args->name, "..", namelen) == 0) {
1490 err = -EINVAL;
1491 goto out;
1492 }
1493
1494 err = mnt_want_write(file->f_path.mnt);
1495 if (err)
1496 goto out;
1497
1498 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
1499 dentry = lookup_one_len(vol_args->name, parent, namelen);
1500 if (IS_ERR(dentry)) {
1501 err = PTR_ERR(dentry);
1502 goto out_unlock_dir;
1503 }
1504
1505 if (!dentry->d_inode) {
1506 err = -ENOENT;
1507 goto out_dput;
1508 }
1509
1510 inode = dentry->d_inode;
1511 dest = BTRFS_I(inode)->root;
1512 if (!capable(CAP_SYS_ADMIN)){
1513 /*
1514 * Regular user. Only allow this with a special mount
1515 * option, when the user has write+exec access to the
1516 * subvol root, and when rmdir(2) would have been
1517 * allowed.
1518 *
1519 * Note that this is _not_ check that the subvol is
1520 * empty or doesn't contain data that we wouldn't
1521 * otherwise be able to delete.
1522 *
1523 * Users who want to delete empty subvols should try
1524 * rmdir(2).
1525 */
1526 err = -EPERM;
1527 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1528 goto out_dput;
1529
1530 /*
1531 * Do not allow deletion if the parent dir is the same
1532 * as the dir to be deleted. That means the ioctl
1533 * must be called on the dentry referencing the root
1534 * of the subvol, not a random directory contained
1535 * within it.
1536 */
1537 err = -EINVAL;
1538 if (root == dest)
1539 goto out_dput;
1540
1541 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
1542 if (err)
1543 goto out_dput;
1544
1545 /* check if subvolume may be deleted by a non-root user */
1546 err = btrfs_may_delete(dir, dentry, 1);
1547 if (err)
1548 goto out_dput;
1549 }
1550
1551 if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) {
1552 err = -EINVAL;
1553 goto out_dput;
1554 }
1555
1556 mutex_lock(&inode->i_mutex);
1557 err = d_invalidate(dentry);
1558 if (err)
1559 goto out_unlock;
1560
1561 down_write(&root->fs_info->subvol_sem);
1562
1563 err = may_destroy_subvol(dest);
1564 if (err)
1565 goto out_up_write;
1566
1567 trans = btrfs_start_transaction(root, 0);
1568 if (IS_ERR(trans)) {
1569 err = PTR_ERR(trans);
1570 goto out_up_write;
1571 }
1572 trans->block_rsv = &root->fs_info->global_block_rsv;
1573
1574 ret = btrfs_unlink_subvol(trans, root, dir,
1575 dest->root_key.objectid,
1576 dentry->d_name.name,
1577 dentry->d_name.len);
1578 BUG_ON(ret);
1579
1580 btrfs_record_root_in_trans(trans, dest);
1581
1582 memset(&dest->root_item.drop_progress, 0,
1583 sizeof(dest->root_item.drop_progress));
1584 dest->root_item.drop_level = 0;
1585 btrfs_set_root_refs(&dest->root_item, 0);
1586
1587 if (!xchg(&dest->orphan_item_inserted, 1)) {
1588 ret = btrfs_insert_orphan_item(trans,
1589 root->fs_info->tree_root,
1590 dest->root_key.objectid);
1591 BUG_ON(ret);
1592 }
1593
1594 ret = btrfs_end_transaction(trans, root);
1595 BUG_ON(ret);
1596 inode->i_flags |= S_DEAD;
1597 out_up_write:
1598 up_write(&root->fs_info->subvol_sem);
1599 out_unlock:
1600 mutex_unlock(&inode->i_mutex);
1601 if (!err) {
1602 shrink_dcache_sb(root->fs_info->sb);
1603 btrfs_invalidate_inodes(dest);
1604 d_delete(dentry);
1605 }
1606 out_dput:
1607 dput(dentry);
1608 out_unlock_dir:
1609 mutex_unlock(&dir->i_mutex);
1610 mnt_drop_write(file->f_path.mnt);
1611 out:
1612 kfree(vol_args);
1613 return err;
1614 }
1615
1616 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
1617 {
1618 struct inode *inode = fdentry(file)->d_inode;
1619 struct btrfs_root *root = BTRFS_I(inode)->root;
1620 struct btrfs_ioctl_defrag_range_args *range;
1621 int ret;
1622
1623 if (btrfs_root_readonly(root))
1624 return -EROFS;
1625
1626 ret = mnt_want_write(file->f_path.mnt);
1627 if (ret)
1628 return ret;
1629
1630 switch (inode->i_mode & S_IFMT) {
1631 case S_IFDIR:
1632 if (!capable(CAP_SYS_ADMIN)) {
1633 ret = -EPERM;
1634 goto out;
1635 }
1636 ret = btrfs_defrag_root(root, 0);
1637 if (ret)
1638 goto out;
1639 ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
1640 break;
1641 case S_IFREG:
1642 if (!(file->f_mode & FMODE_WRITE)) {
1643 ret = -EINVAL;
1644 goto out;
1645 }
1646
1647 range = kzalloc(sizeof(*range), GFP_KERNEL);
1648 if (!range) {
1649 ret = -ENOMEM;
1650 goto out;
1651 }
1652
1653 if (argp) {
1654 if (copy_from_user(range, argp,
1655 sizeof(*range))) {
1656 ret = -EFAULT;
1657 kfree(range);
1658 goto out;
1659 }
1660 /* compression requires us to start the IO */
1661 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1662 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
1663 range->extent_thresh = (u32)-1;
1664 }
1665 } else {
1666 /* the rest are all set to zero by kzalloc */
1667 range->len = (u64)-1;
1668 }
1669 ret = btrfs_defrag_file(file, range);
1670 kfree(range);
1671 break;
1672 default:
1673 ret = -EINVAL;
1674 }
1675 out:
1676 mnt_drop_write(file->f_path.mnt);
1677 return ret;
1678 }
1679
1680 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
1681 {
1682 struct btrfs_ioctl_vol_args *vol_args;
1683 int ret;
1684
1685 if (!capable(CAP_SYS_ADMIN))
1686 return -EPERM;
1687
1688 vol_args = memdup_user(arg, sizeof(*vol_args));
1689 if (IS_ERR(vol_args))
1690 return PTR_ERR(vol_args);
1691
1692 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1693 ret = btrfs_init_new_device(root, vol_args->name);
1694
1695 kfree(vol_args);
1696 return ret;
1697 }
1698
1699 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
1700 {
1701 struct btrfs_ioctl_vol_args *vol_args;
1702 int ret;
1703
1704 if (!capable(CAP_SYS_ADMIN))
1705 return -EPERM;
1706
1707 if (root->fs_info->sb->s_flags & MS_RDONLY)
1708 return -EROFS;
1709
1710 vol_args = memdup_user(arg, sizeof(*vol_args));
1711 if (IS_ERR(vol_args))
1712 return PTR_ERR(vol_args);
1713
1714 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1715 ret = btrfs_rm_device(root, vol_args->name);
1716
1717 kfree(vol_args);
1718 return ret;
1719 }
1720
1721 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
1722 u64 off, u64 olen, u64 destoff)
1723 {
1724 struct inode *inode = fdentry(file)->d_inode;
1725 struct btrfs_root *root = BTRFS_I(inode)->root;
1726 struct file *src_file;
1727 struct inode *src;
1728 struct btrfs_trans_handle *trans;
1729 struct btrfs_path *path;
1730 struct extent_buffer *leaf;
1731 char *buf;
1732 struct btrfs_key key;
1733 u32 nritems;
1734 int slot;
1735 int ret;
1736 u64 len = olen;
1737 u64 bs = root->fs_info->sb->s_blocksize;
1738 u64 hint_byte;
1739
1740 /*
1741 * TODO:
1742 * - split compressed inline extents. annoying: we need to
1743 * decompress into destination's address_space (the file offset
1744 * may change, so source mapping won't do), then recompress (or
1745 * otherwise reinsert) a subrange.
1746 * - allow ranges within the same file to be cloned (provided
1747 * they don't overlap)?
1748 */
1749
1750 /* the destination must be opened for writing */
1751 if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
1752 return -EINVAL;
1753
1754 if (btrfs_root_readonly(root))
1755 return -EROFS;
1756
1757 ret = mnt_want_write(file->f_path.mnt);
1758 if (ret)
1759 return ret;
1760
1761 src_file = fget(srcfd);
1762 if (!src_file) {
1763 ret = -EBADF;
1764 goto out_drop_write;
1765 }
1766
1767 src = src_file->f_dentry->d_inode;
1768
1769 ret = -EINVAL;
1770 if (src == inode)
1771 goto out_fput;
1772
1773 /* the src must be open for reading */
1774 if (!(src_file->f_mode & FMODE_READ))
1775 goto out_fput;
1776
1777 ret = -EISDIR;
1778 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
1779 goto out_fput;
1780
1781 ret = -EXDEV;
1782 if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
1783 goto out_fput;
1784
1785 ret = -ENOMEM;
1786 buf = vmalloc(btrfs_level_size(root, 0));
1787 if (!buf)
1788 goto out_fput;
1789
1790 path = btrfs_alloc_path();
1791 if (!path) {
1792 vfree(buf);
1793 goto out_fput;
1794 }
1795 path->reada = 2;
1796
1797 if (inode < src) {
1798 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
1799 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
1800 } else {
1801 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
1802 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
1803 }
1804
1805 /* determine range to clone */
1806 ret = -EINVAL;
1807 if (off + len > src->i_size || off + len < off)
1808 goto out_unlock;
1809 if (len == 0)
1810 olen = len = src->i_size - off;
1811 /* if we extend to eof, continue to block boundary */
1812 if (off + len == src->i_size)
1813 len = ALIGN(src->i_size, bs) - off;
1814
1815 /* verify the end result is block aligned */
1816 if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
1817 !IS_ALIGNED(destoff, bs))
1818 goto out_unlock;
1819
1820 /* do any pending delalloc/csum calc on src, one way or
1821 another, and lock file content */
1822 while (1) {
1823 struct btrfs_ordered_extent *ordered;
1824 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1825 ordered = btrfs_lookup_first_ordered_extent(src, off+len);
1826 if (!ordered &&
1827 !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len,
1828 EXTENT_DELALLOC, 0, NULL))
1829 break;
1830 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1831 if (ordered)
1832 btrfs_put_ordered_extent(ordered);
1833 btrfs_wait_ordered_range(src, off, len);
1834 }
1835
1836 /* clone data */
1837 key.objectid = src->i_ino;
1838 key.type = BTRFS_EXTENT_DATA_KEY;
1839 key.offset = 0;
1840
1841 while (1) {
1842 /*
1843 * note the key will change type as we walk through the
1844 * tree.
1845 */
1846 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1847 if (ret < 0)
1848 goto out;
1849
1850 nritems = btrfs_header_nritems(path->nodes[0]);
1851 if (path->slots[0] >= nritems) {
1852 ret = btrfs_next_leaf(root, path);
1853 if (ret < 0)
1854 goto out;
1855 if (ret > 0)
1856 break;
1857 nritems = btrfs_header_nritems(path->nodes[0]);
1858 }
1859 leaf = path->nodes[0];
1860 slot = path->slots[0];
1861
1862 btrfs_item_key_to_cpu(leaf, &key, slot);
1863 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
1864 key.objectid != src->i_ino)
1865 break;
1866
1867 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
1868 struct btrfs_file_extent_item *extent;
1869 int type;
1870 u32 size;
1871 struct btrfs_key new_key;
1872 u64 disko = 0, diskl = 0;
1873 u64 datao = 0, datal = 0;
1874 u8 comp;
1875 u64 endoff;
1876
1877 size = btrfs_item_size_nr(leaf, slot);
1878 read_extent_buffer(leaf, buf,
1879 btrfs_item_ptr_offset(leaf, slot),
1880 size);
1881
1882 extent = btrfs_item_ptr(leaf, slot,
1883 struct btrfs_file_extent_item);
1884 comp = btrfs_file_extent_compression(leaf, extent);
1885 type = btrfs_file_extent_type(leaf, extent);
1886 if (type == BTRFS_FILE_EXTENT_REG ||
1887 type == BTRFS_FILE_EXTENT_PREALLOC) {
1888 disko = btrfs_file_extent_disk_bytenr(leaf,
1889 extent);
1890 diskl = btrfs_file_extent_disk_num_bytes(leaf,
1891 extent);
1892 datao = btrfs_file_extent_offset(leaf, extent);
1893 datal = btrfs_file_extent_num_bytes(leaf,
1894 extent);
1895 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1896 /* take upper bound, may be compressed */
1897 datal = btrfs_file_extent_ram_bytes(leaf,
1898 extent);
1899 }
1900 btrfs_release_path(root, path);
1901
1902 if (key.offset + datal <= off ||
1903 key.offset >= off+len)
1904 goto next;
1905
1906 memcpy(&new_key, &key, sizeof(new_key));
1907 new_key.objectid = inode->i_ino;
1908 if (off <= key.offset)
1909 new_key.offset = key.offset + destoff - off;
1910 else
1911 new_key.offset = destoff;
1912
1913 trans = btrfs_start_transaction(root, 1);
1914 if (IS_ERR(trans)) {
1915 ret = PTR_ERR(trans);
1916 goto out;
1917 }
1918
1919 if (type == BTRFS_FILE_EXTENT_REG ||
1920 type == BTRFS_FILE_EXTENT_PREALLOC) {
1921 if (off > key.offset) {
1922 datao += off - key.offset;
1923 datal -= off - key.offset;
1924 }
1925
1926 if (key.offset + datal > off + len)
1927 datal = off + len - key.offset;
1928
1929 ret = btrfs_drop_extents(trans, inode,
1930 new_key.offset,
1931 new_key.offset + datal,
1932 &hint_byte, 1);
1933 BUG_ON(ret);
1934
1935 ret = btrfs_insert_empty_item(trans, root, path,
1936 &new_key, size);
1937 BUG_ON(ret);
1938
1939 leaf = path->nodes[0];
1940 slot = path->slots[0];
1941 write_extent_buffer(leaf, buf,
1942 btrfs_item_ptr_offset(leaf, slot),
1943 size);
1944
1945 extent = btrfs_item_ptr(leaf, slot,
1946 struct btrfs_file_extent_item);
1947
1948 /* disko == 0 means it's a hole */
1949 if (!disko)
1950 datao = 0;
1951
1952 btrfs_set_file_extent_offset(leaf, extent,
1953 datao);
1954 btrfs_set_file_extent_num_bytes(leaf, extent,
1955 datal);
1956 if (disko) {
1957 inode_add_bytes(inode, datal);
1958 ret = btrfs_inc_extent_ref(trans, root,
1959 disko, diskl, 0,
1960 root->root_key.objectid,
1961 inode->i_ino,
1962 new_key.offset - datao);
1963 BUG_ON(ret);
1964 }
1965 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1966 u64 skip = 0;
1967 u64 trim = 0;
1968 if (off > key.offset) {
1969 skip = off - key.offset;
1970 new_key.offset += skip;
1971 }
1972
1973 if (key.offset + datal > off+len)
1974 trim = key.offset + datal - (off+len);
1975
1976 if (comp && (skip || trim)) {
1977 ret = -EINVAL;
1978 btrfs_end_transaction(trans, root);
1979 goto out;
1980 }
1981 size -= skip + trim;
1982 datal -= skip + trim;
1983
1984 ret = btrfs_drop_extents(trans, inode,
1985 new_key.offset,
1986 new_key.offset + datal,
1987 &hint_byte, 1);
1988 BUG_ON(ret);
1989
1990 ret = btrfs_insert_empty_item(trans, root, path,
1991 &new_key, size);
1992 BUG_ON(ret);
1993
1994 if (skip) {
1995 u32 start =
1996 btrfs_file_extent_calc_inline_size(0);
1997 memmove(buf+start, buf+start+skip,
1998 datal);
1999 }
2000
2001 leaf = path->nodes[0];
2002 slot = path->slots[0];
2003 write_extent_buffer(leaf, buf,
2004 btrfs_item_ptr_offset(leaf, slot),
2005 size);
2006 inode_add_bytes(inode, datal);
2007 }
2008
2009 btrfs_mark_buffer_dirty(leaf);
2010 btrfs_release_path(root, path);
2011
2012 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2013
2014 /*
2015 * we round up to the block size at eof when
2016 * determining which extents to clone above,
2017 * but shouldn't round up the file size
2018 */
2019 endoff = new_key.offset + datal;
2020 if (endoff > destoff+olen)
2021 endoff = destoff+olen;
2022 if (endoff > inode->i_size)
2023 btrfs_i_size_write(inode, endoff);
2024
2025 BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
2026 ret = btrfs_update_inode(trans, root, inode);
2027 BUG_ON(ret);
2028 btrfs_end_transaction(trans, root);
2029 }
2030 next:
2031 btrfs_release_path(root, path);
2032 key.offset++;
2033 }
2034 ret = 0;
2035 out:
2036 btrfs_release_path(root, path);
2037 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2038 out_unlock:
2039 mutex_unlock(&src->i_mutex);
2040 mutex_unlock(&inode->i_mutex);
2041 vfree(buf);
2042 btrfs_free_path(path);
2043 out_fput:
2044 fput(src_file);
2045 out_drop_write:
2046 mnt_drop_write(file->f_path.mnt);
2047 return ret;
2048 }
2049
2050 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2051 {
2052 struct btrfs_ioctl_clone_range_args args;
2053
2054 if (copy_from_user(&args, argp, sizeof(args)))
2055 return -EFAULT;
2056 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2057 args.src_length, args.dest_offset);
2058 }
2059
2060 /*
2061 * there are many ways the trans_start and trans_end ioctls can lead
2062 * to deadlocks. They should only be used by applications that
2063 * basically own the machine, and have a very in depth understanding
2064 * of all the possible deadlocks and enospc problems.
2065 */
2066 static long btrfs_ioctl_trans_start(struct file *file)
2067 {
2068 struct inode *inode = fdentry(file)->d_inode;
2069 struct btrfs_root *root = BTRFS_I(inode)->root;
2070 struct btrfs_trans_handle *trans;
2071 int ret;
2072
2073 ret = -EPERM;
2074 if (!capable(CAP_SYS_ADMIN))
2075 goto out;
2076
2077 ret = -EINPROGRESS;
2078 if (file->private_data)
2079 goto out;
2080
2081 ret = -EROFS;
2082 if (btrfs_root_readonly(root))
2083 goto out;
2084
2085 ret = mnt_want_write(file->f_path.mnt);
2086 if (ret)
2087 goto out;
2088
2089 mutex_lock(&root->fs_info->trans_mutex);
2090 root->fs_info->open_ioctl_trans++;
2091 mutex_unlock(&root->fs_info->trans_mutex);
2092
2093 ret = -ENOMEM;
2094 trans = btrfs_start_ioctl_transaction(root, 0);
2095 if (IS_ERR(trans))
2096 goto out_drop;
2097
2098 file->private_data = trans;
2099 return 0;
2100
2101 out_drop:
2102 mutex_lock(&root->fs_info->trans_mutex);
2103 root->fs_info->open_ioctl_trans--;
2104 mutex_unlock(&root->fs_info->trans_mutex);
2105 mnt_drop_write(file->f_path.mnt);
2106 out:
2107 return ret;
2108 }
2109
2110 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2111 {
2112 struct inode *inode = fdentry(file)->d_inode;
2113 struct btrfs_root *root = BTRFS_I(inode)->root;
2114 struct btrfs_root *new_root;
2115 struct btrfs_dir_item *di;
2116 struct btrfs_trans_handle *trans;
2117 struct btrfs_path *path;
2118 struct btrfs_key location;
2119 struct btrfs_disk_key disk_key;
2120 struct btrfs_super_block *disk_super;
2121 u64 features;
2122 u64 objectid = 0;
2123 u64 dir_id;
2124
2125 if (!capable(CAP_SYS_ADMIN))
2126 return -EPERM;
2127
2128 if (copy_from_user(&objectid, argp, sizeof(objectid)))
2129 return -EFAULT;
2130
2131 if (!objectid)
2132 objectid = root->root_key.objectid;
2133
2134 location.objectid = objectid;
2135 location.type = BTRFS_ROOT_ITEM_KEY;
2136 location.offset = (u64)-1;
2137
2138 new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2139 if (IS_ERR(new_root))
2140 return PTR_ERR(new_root);
2141
2142 if (btrfs_root_refs(&new_root->root_item) == 0)
2143 return -ENOENT;
2144
2145 path = btrfs_alloc_path();
2146 if (!path)
2147 return -ENOMEM;
2148 path->leave_spinning = 1;
2149
2150 trans = btrfs_start_transaction(root, 1);
2151 if (IS_ERR(trans)) {
2152 btrfs_free_path(path);
2153 return PTR_ERR(trans);
2154 }
2155
2156 dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
2157 di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2158 dir_id, "default", 7, 1);
2159 if (IS_ERR_OR_NULL(di)) {
2160 btrfs_free_path(path);
2161 btrfs_end_transaction(trans, root);
2162 printk(KERN_ERR "Umm, you don't have the default dir item, "
2163 "this isn't going to work\n");
2164 return -ENOENT;
2165 }
2166
2167 btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2168 btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2169 btrfs_mark_buffer_dirty(path->nodes[0]);
2170 btrfs_free_path(path);
2171
2172 disk_super = &root->fs_info->super_copy;
2173 features = btrfs_super_incompat_flags(disk_super);
2174 if (!(features & BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)) {
2175 features |= BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL;
2176 btrfs_set_super_incompat_flags(disk_super, features);
2177 }
2178 btrfs_end_transaction(trans, root);
2179
2180 return 0;
2181 }
2182
2183 static void get_block_group_info(struct list_head *groups_list,
2184 struct btrfs_ioctl_space_info *space)
2185 {
2186 struct btrfs_block_group_cache *block_group;
2187
2188 space->total_bytes = 0;
2189 space->used_bytes = 0;
2190 space->flags = 0;
2191 list_for_each_entry(block_group, groups_list, list) {
2192 space->flags = block_group->flags;
2193 space->total_bytes += block_group->key.offset;
2194 space->used_bytes +=
2195 btrfs_block_group_used(&block_group->item);
2196 }
2197 }
2198
2199 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
2200 {
2201 struct btrfs_ioctl_space_args space_args;
2202 struct btrfs_ioctl_space_info space;
2203 struct btrfs_ioctl_space_info *dest;
2204 struct btrfs_ioctl_space_info *dest_orig;
2205 struct btrfs_ioctl_space_info *user_dest;
2206 struct btrfs_space_info *info;
2207 u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2208 BTRFS_BLOCK_GROUP_SYSTEM,
2209 BTRFS_BLOCK_GROUP_METADATA,
2210 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2211 int num_types = 4;
2212 int alloc_size;
2213 int ret = 0;
2214 u64 slot_count = 0;
2215 int i, c;
2216
2217 if (copy_from_user(&space_args,
2218 (struct btrfs_ioctl_space_args __user *)arg,
2219 sizeof(space_args)))
2220 return -EFAULT;
2221
2222 for (i = 0; i < num_types; i++) {
2223 struct btrfs_space_info *tmp;
2224
2225 info = NULL;
2226 rcu_read_lock();
2227 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2228 list) {
2229 if (tmp->flags == types[i]) {
2230 info = tmp;
2231 break;
2232 }
2233 }
2234 rcu_read_unlock();
2235
2236 if (!info)
2237 continue;
2238
2239 down_read(&info->groups_sem);
2240 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2241 if (!list_empty(&info->block_groups[c]))
2242 slot_count++;
2243 }
2244 up_read(&info->groups_sem);
2245 }
2246
2247 /* space_slots == 0 means they are asking for a count */
2248 if (space_args.space_slots == 0) {
2249 space_args.total_spaces = slot_count;
2250 goto out;
2251 }
2252
2253 slot_count = min_t(u64, space_args.space_slots, slot_count);
2254
2255 alloc_size = sizeof(*dest) * slot_count;
2256
2257 /* we generally have at most 6 or so space infos, one for each raid
2258 * level. So, a whole page should be more than enough for everyone
2259 */
2260 if (alloc_size > PAGE_CACHE_SIZE)
2261 return -ENOMEM;
2262
2263 space_args.total_spaces = 0;
2264 dest = kmalloc(alloc_size, GFP_NOFS);
2265 if (!dest)
2266 return -ENOMEM;
2267 dest_orig = dest;
2268
2269 /* now we have a buffer to copy into */
2270 for (i = 0; i < num_types; i++) {
2271 struct btrfs_space_info *tmp;
2272
2273 if (!slot_count)
2274 break;
2275
2276 info = NULL;
2277 rcu_read_lock();
2278 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2279 list) {
2280 if (tmp->flags == types[i]) {
2281 info = tmp;
2282 break;
2283 }
2284 }
2285 rcu_read_unlock();
2286
2287 if (!info)
2288 continue;
2289 down_read(&info->groups_sem);
2290 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2291 if (!list_empty(&info->block_groups[c])) {
2292 get_block_group_info(&info->block_groups[c],
2293 &space);
2294 memcpy(dest, &space, sizeof(space));
2295 dest++;
2296 space_args.total_spaces++;
2297 slot_count--;
2298 }
2299 if (!slot_count)
2300 break;
2301 }
2302 up_read(&info->groups_sem);
2303 }
2304
2305 user_dest = (struct btrfs_ioctl_space_info *)
2306 (arg + sizeof(struct btrfs_ioctl_space_args));
2307
2308 if (copy_to_user(user_dest, dest_orig, alloc_size))
2309 ret = -EFAULT;
2310
2311 kfree(dest_orig);
2312 out:
2313 if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
2314 ret = -EFAULT;
2315
2316 return ret;
2317 }
2318
2319 /*
2320 * there are many ways the trans_start and trans_end ioctls can lead
2321 * to deadlocks. They should only be used by applications that
2322 * basically own the machine, and have a very in depth understanding
2323 * of all the possible deadlocks and enospc problems.
2324 */
2325 long btrfs_ioctl_trans_end(struct file *file)
2326 {
2327 struct inode *inode = fdentry(file)->d_inode;
2328 struct btrfs_root *root = BTRFS_I(inode)->root;
2329 struct btrfs_trans_handle *trans;
2330
2331 trans = file->private_data;
2332 if (!trans)
2333 return -EINVAL;
2334 file->private_data = NULL;
2335
2336 btrfs_end_transaction(trans, root);
2337
2338 mutex_lock(&root->fs_info->trans_mutex);
2339 root->fs_info->open_ioctl_trans--;
2340 mutex_unlock(&root->fs_info->trans_mutex);
2341
2342 mnt_drop_write(file->f_path.mnt);
2343 return 0;
2344 }
2345
2346 static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp)
2347 {
2348 struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2349 struct btrfs_trans_handle *trans;
2350 u64 transid;
2351
2352 trans = btrfs_start_transaction(root, 0);
2353 if (IS_ERR(trans))
2354 return PTR_ERR(trans);
2355 transid = trans->transid;
2356 btrfs_commit_transaction_async(trans, root, 0);
2357
2358 if (argp)
2359 if (copy_to_user(argp, &transid, sizeof(transid)))
2360 return -EFAULT;
2361 return 0;
2362 }
2363
2364 static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp)
2365 {
2366 struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2367 u64 transid;
2368
2369 if (argp) {
2370 if (copy_from_user(&transid, argp, sizeof(transid)))
2371 return -EFAULT;
2372 } else {
2373 transid = 0; /* current trans */
2374 }
2375 return btrfs_wait_for_commit(root, transid);
2376 }
2377
2378 long btrfs_ioctl(struct file *file, unsigned int
2379 cmd, unsigned long arg)
2380 {
2381 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2382 void __user *argp = (void __user *)arg;
2383
2384 switch (cmd) {
2385 case FS_IOC_GETFLAGS:
2386 return btrfs_ioctl_getflags(file, argp);
2387 case FS_IOC_SETFLAGS:
2388 return btrfs_ioctl_setflags(file, argp);
2389 case FS_IOC_GETVERSION:
2390 return btrfs_ioctl_getversion(file, argp);
2391 case BTRFS_IOC_SNAP_CREATE:
2392 return btrfs_ioctl_snap_create(file, argp, 0);
2393 case BTRFS_IOC_SNAP_CREATE_V2:
2394 return btrfs_ioctl_snap_create_v2(file, argp, 0);
2395 case BTRFS_IOC_SUBVOL_CREATE:
2396 return btrfs_ioctl_snap_create(file, argp, 1);
2397 case BTRFS_IOC_SNAP_DESTROY:
2398 return btrfs_ioctl_snap_destroy(file, argp);
2399 case BTRFS_IOC_SUBVOL_GETFLAGS:
2400 return btrfs_ioctl_subvol_getflags(file, argp);
2401 case BTRFS_IOC_SUBVOL_SETFLAGS:
2402 return btrfs_ioctl_subvol_setflags(file, argp);
2403 case BTRFS_IOC_DEFAULT_SUBVOL:
2404 return btrfs_ioctl_default_subvol(file, argp);
2405 case BTRFS_IOC_DEFRAG:
2406 return btrfs_ioctl_defrag(file, NULL);
2407 case BTRFS_IOC_DEFRAG_RANGE:
2408 return btrfs_ioctl_defrag(file, argp);
2409 case BTRFS_IOC_RESIZE:
2410 return btrfs_ioctl_resize(root, argp);
2411 case BTRFS_IOC_ADD_DEV:
2412 return btrfs_ioctl_add_dev(root, argp);
2413 case BTRFS_IOC_RM_DEV:
2414 return btrfs_ioctl_rm_dev(root, argp);
2415 case BTRFS_IOC_BALANCE:
2416 return btrfs_balance(root->fs_info->dev_root);
2417 case BTRFS_IOC_CLONE:
2418 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
2419 case BTRFS_IOC_CLONE_RANGE:
2420 return btrfs_ioctl_clone_range(file, argp);
2421 case BTRFS_IOC_TRANS_START:
2422 return btrfs_ioctl_trans_start(file);
2423 case BTRFS_IOC_TRANS_END:
2424 return btrfs_ioctl_trans_end(file);
2425 case BTRFS_IOC_TREE_SEARCH:
2426 return btrfs_ioctl_tree_search(file, argp);
2427 case BTRFS_IOC_INO_LOOKUP:
2428 return btrfs_ioctl_ino_lookup(file, argp);
2429 case BTRFS_IOC_SPACE_INFO:
2430 return btrfs_ioctl_space_info(root, argp);
2431 case BTRFS_IOC_SYNC:
2432 btrfs_sync_fs(file->f_dentry->d_sb, 1);
2433 return 0;
2434 case BTRFS_IOC_START_SYNC:
2435 return btrfs_ioctl_start_sync(file, argp);
2436 case BTRFS_IOC_WAIT_SYNC:
2437 return btrfs_ioctl_wait_sync(file, argp);
2438 }
2439
2440 return -ENOTTY;
2441 }
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