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Staging: Merge branch 'tidspbridge-for-2.6.39' of git://dev.omapzoom.org/pub/scm...
[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 "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 (!is_owner_or_cap(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(!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 ret = btrfs_grow_device(trans, device, new_size);
911 btrfs_commit_transaction(trans, root);
912 } else {
913 ret = btrfs_shrink_device(device, new_size);
914 }
915
916 out_unlock:
917 mutex_unlock(&root->fs_info->volume_mutex);
918 kfree(vol_args);
919 return ret;
920 }
921
922 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
923 char *name,
924 unsigned long fd,
925 int subvol,
926 u64 *transid,
927 bool readonly)
928 {
929 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
930 struct file *src_file;
931 int namelen;
932 int ret = 0;
933
934 if (root->fs_info->sb->s_flags & MS_RDONLY)
935 return -EROFS;
936
937 namelen = strlen(name);
938 if (strchr(name, '/')) {
939 ret = -EINVAL;
940 goto out;
941 }
942
943 if (subvol) {
944 ret = btrfs_mksubvol(&file->f_path, name, namelen,
945 NULL, transid, readonly);
946 } else {
947 struct inode *src_inode;
948 src_file = fget(fd);
949 if (!src_file) {
950 ret = -EINVAL;
951 goto out;
952 }
953
954 src_inode = src_file->f_path.dentry->d_inode;
955 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
956 printk(KERN_INFO "btrfs: Snapshot src from "
957 "another FS\n");
958 ret = -EINVAL;
959 fput(src_file);
960 goto out;
961 }
962 ret = btrfs_mksubvol(&file->f_path, name, namelen,
963 BTRFS_I(src_inode)->root,
964 transid, readonly);
965 fput(src_file);
966 }
967 out:
968 return ret;
969 }
970
971 static noinline int btrfs_ioctl_snap_create(struct file *file,
972 void __user *arg, int subvol)
973 {
974 struct btrfs_ioctl_vol_args *vol_args;
975 int ret;
976
977 vol_args = memdup_user(arg, sizeof(*vol_args));
978 if (IS_ERR(vol_args))
979 return PTR_ERR(vol_args);
980 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
981
982 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
983 vol_args->fd, subvol,
984 NULL, false);
985
986 kfree(vol_args);
987 return ret;
988 }
989
990 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
991 void __user *arg, int subvol)
992 {
993 struct btrfs_ioctl_vol_args_v2 *vol_args;
994 int ret;
995 u64 transid = 0;
996 u64 *ptr = NULL;
997 bool readonly = false;
998
999 vol_args = memdup_user(arg, sizeof(*vol_args));
1000 if (IS_ERR(vol_args))
1001 return PTR_ERR(vol_args);
1002 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1003
1004 if (vol_args->flags &
1005 ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY)) {
1006 ret = -EOPNOTSUPP;
1007 goto out;
1008 }
1009
1010 if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1011 ptr = &transid;
1012 if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1013 readonly = true;
1014
1015 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1016 vol_args->fd, subvol,
1017 ptr, readonly);
1018
1019 if (ret == 0 && ptr &&
1020 copy_to_user(arg +
1021 offsetof(struct btrfs_ioctl_vol_args_v2,
1022 transid), ptr, sizeof(*ptr)))
1023 ret = -EFAULT;
1024 out:
1025 kfree(vol_args);
1026 return ret;
1027 }
1028
1029 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1030 void __user *arg)
1031 {
1032 struct inode *inode = fdentry(file)->d_inode;
1033 struct btrfs_root *root = BTRFS_I(inode)->root;
1034 int ret = 0;
1035 u64 flags = 0;
1036
1037 if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID)
1038 return -EINVAL;
1039
1040 down_read(&root->fs_info->subvol_sem);
1041 if (btrfs_root_readonly(root))
1042 flags |= BTRFS_SUBVOL_RDONLY;
1043 up_read(&root->fs_info->subvol_sem);
1044
1045 if (copy_to_user(arg, &flags, sizeof(flags)))
1046 ret = -EFAULT;
1047
1048 return ret;
1049 }
1050
1051 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1052 void __user *arg)
1053 {
1054 struct inode *inode = fdentry(file)->d_inode;
1055 struct btrfs_root *root = BTRFS_I(inode)->root;
1056 struct btrfs_trans_handle *trans;
1057 u64 root_flags;
1058 u64 flags;
1059 int ret = 0;
1060
1061 if (root->fs_info->sb->s_flags & MS_RDONLY)
1062 return -EROFS;
1063
1064 if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID)
1065 return -EINVAL;
1066
1067 if (copy_from_user(&flags, arg, sizeof(flags)))
1068 return -EFAULT;
1069
1070 if (flags & ~BTRFS_SUBVOL_CREATE_ASYNC)
1071 return -EINVAL;
1072
1073 if (flags & ~BTRFS_SUBVOL_RDONLY)
1074 return -EOPNOTSUPP;
1075
1076 down_write(&root->fs_info->subvol_sem);
1077
1078 /* nothing to do */
1079 if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1080 goto out;
1081
1082 root_flags = btrfs_root_flags(&root->root_item);
1083 if (flags & BTRFS_SUBVOL_RDONLY)
1084 btrfs_set_root_flags(&root->root_item,
1085 root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1086 else
1087 btrfs_set_root_flags(&root->root_item,
1088 root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1089
1090 trans = btrfs_start_transaction(root, 1);
1091 if (IS_ERR(trans)) {
1092 ret = PTR_ERR(trans);
1093 goto out_reset;
1094 }
1095
1096 ret = btrfs_update_root(trans, root,
1097 &root->root_key, &root->root_item);
1098
1099 btrfs_commit_transaction(trans, root);
1100 out_reset:
1101 if (ret)
1102 btrfs_set_root_flags(&root->root_item, root_flags);
1103 out:
1104 up_write(&root->fs_info->subvol_sem);
1105 return ret;
1106 }
1107
1108 /*
1109 * helper to check if the subvolume references other subvolumes
1110 */
1111 static noinline int may_destroy_subvol(struct btrfs_root *root)
1112 {
1113 struct btrfs_path *path;
1114 struct btrfs_key key;
1115 int ret;
1116
1117 path = btrfs_alloc_path();
1118 if (!path)
1119 return -ENOMEM;
1120
1121 key.objectid = root->root_key.objectid;
1122 key.type = BTRFS_ROOT_REF_KEY;
1123 key.offset = (u64)-1;
1124
1125 ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1126 &key, path, 0, 0);
1127 if (ret < 0)
1128 goto out;
1129 BUG_ON(ret == 0);
1130
1131 ret = 0;
1132 if (path->slots[0] > 0) {
1133 path->slots[0]--;
1134 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1135 if (key.objectid == root->root_key.objectid &&
1136 key.type == BTRFS_ROOT_REF_KEY)
1137 ret = -ENOTEMPTY;
1138 }
1139 out:
1140 btrfs_free_path(path);
1141 return ret;
1142 }
1143
1144 static noinline int key_in_sk(struct btrfs_key *key,
1145 struct btrfs_ioctl_search_key *sk)
1146 {
1147 struct btrfs_key test;
1148 int ret;
1149
1150 test.objectid = sk->min_objectid;
1151 test.type = sk->min_type;
1152 test.offset = sk->min_offset;
1153
1154 ret = btrfs_comp_cpu_keys(key, &test);
1155 if (ret < 0)
1156 return 0;
1157
1158 test.objectid = sk->max_objectid;
1159 test.type = sk->max_type;
1160 test.offset = sk->max_offset;
1161
1162 ret = btrfs_comp_cpu_keys(key, &test);
1163 if (ret > 0)
1164 return 0;
1165 return 1;
1166 }
1167
1168 static noinline int copy_to_sk(struct btrfs_root *root,
1169 struct btrfs_path *path,
1170 struct btrfs_key *key,
1171 struct btrfs_ioctl_search_key *sk,
1172 char *buf,
1173 unsigned long *sk_offset,
1174 int *num_found)
1175 {
1176 u64 found_transid;
1177 struct extent_buffer *leaf;
1178 struct btrfs_ioctl_search_header sh;
1179 unsigned long item_off;
1180 unsigned long item_len;
1181 int nritems;
1182 int i;
1183 int slot;
1184 int found = 0;
1185 int ret = 0;
1186
1187 leaf = path->nodes[0];
1188 slot = path->slots[0];
1189 nritems = btrfs_header_nritems(leaf);
1190
1191 if (btrfs_header_generation(leaf) > sk->max_transid) {
1192 i = nritems;
1193 goto advance_key;
1194 }
1195 found_transid = btrfs_header_generation(leaf);
1196
1197 for (i = slot; i < nritems; i++) {
1198 item_off = btrfs_item_ptr_offset(leaf, i);
1199 item_len = btrfs_item_size_nr(leaf, i);
1200
1201 if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1202 item_len = 0;
1203
1204 if (sizeof(sh) + item_len + *sk_offset >
1205 BTRFS_SEARCH_ARGS_BUFSIZE) {
1206 ret = 1;
1207 goto overflow;
1208 }
1209
1210 btrfs_item_key_to_cpu(leaf, key, i);
1211 if (!key_in_sk(key, sk))
1212 continue;
1213
1214 sh.objectid = key->objectid;
1215 sh.offset = key->offset;
1216 sh.type = key->type;
1217 sh.len = item_len;
1218 sh.transid = found_transid;
1219
1220 /* copy search result header */
1221 memcpy(buf + *sk_offset, &sh, sizeof(sh));
1222 *sk_offset += sizeof(sh);
1223
1224 if (item_len) {
1225 char *p = buf + *sk_offset;
1226 /* copy the item */
1227 read_extent_buffer(leaf, p,
1228 item_off, item_len);
1229 *sk_offset += item_len;
1230 }
1231 found++;
1232
1233 if (*num_found >= sk->nr_items)
1234 break;
1235 }
1236 advance_key:
1237 ret = 0;
1238 if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1239 key->offset++;
1240 else if (key->type < (u8)-1 && key->type < sk->max_type) {
1241 key->offset = 0;
1242 key->type++;
1243 } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1244 key->offset = 0;
1245 key->type = 0;
1246 key->objectid++;
1247 } else
1248 ret = 1;
1249 overflow:
1250 *num_found += found;
1251 return ret;
1252 }
1253
1254 static noinline int search_ioctl(struct inode *inode,
1255 struct btrfs_ioctl_search_args *args)
1256 {
1257 struct btrfs_root *root;
1258 struct btrfs_key key;
1259 struct btrfs_key max_key;
1260 struct btrfs_path *path;
1261 struct btrfs_ioctl_search_key *sk = &args->key;
1262 struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1263 int ret;
1264 int num_found = 0;
1265 unsigned long sk_offset = 0;
1266
1267 path = btrfs_alloc_path();
1268 if (!path)
1269 return -ENOMEM;
1270
1271 if (sk->tree_id == 0) {
1272 /* search the root of the inode that was passed */
1273 root = BTRFS_I(inode)->root;
1274 } else {
1275 key.objectid = sk->tree_id;
1276 key.type = BTRFS_ROOT_ITEM_KEY;
1277 key.offset = (u64)-1;
1278 root = btrfs_read_fs_root_no_name(info, &key);
1279 if (IS_ERR(root)) {
1280 printk(KERN_ERR "could not find root %llu\n",
1281 sk->tree_id);
1282 btrfs_free_path(path);
1283 return -ENOENT;
1284 }
1285 }
1286
1287 key.objectid = sk->min_objectid;
1288 key.type = sk->min_type;
1289 key.offset = sk->min_offset;
1290
1291 max_key.objectid = sk->max_objectid;
1292 max_key.type = sk->max_type;
1293 max_key.offset = sk->max_offset;
1294
1295 path->keep_locks = 1;
1296
1297 while(1) {
1298 ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1299 sk->min_transid);
1300 if (ret != 0) {
1301 if (ret > 0)
1302 ret = 0;
1303 goto err;
1304 }
1305 ret = copy_to_sk(root, path, &key, sk, args->buf,
1306 &sk_offset, &num_found);
1307 btrfs_release_path(root, path);
1308 if (ret || num_found >= sk->nr_items)
1309 break;
1310
1311 }
1312 ret = 0;
1313 err:
1314 sk->nr_items = num_found;
1315 btrfs_free_path(path);
1316 return ret;
1317 }
1318
1319 static noinline int btrfs_ioctl_tree_search(struct file *file,
1320 void __user *argp)
1321 {
1322 struct btrfs_ioctl_search_args *args;
1323 struct inode *inode;
1324 int ret;
1325
1326 if (!capable(CAP_SYS_ADMIN))
1327 return -EPERM;
1328
1329 args = memdup_user(argp, sizeof(*args));
1330 if (IS_ERR(args))
1331 return PTR_ERR(args);
1332
1333 inode = fdentry(file)->d_inode;
1334 ret = search_ioctl(inode, args);
1335 if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1336 ret = -EFAULT;
1337 kfree(args);
1338 return ret;
1339 }
1340
1341 /*
1342 * Search INODE_REFs to identify path name of 'dirid' directory
1343 * in a 'tree_id' tree. and sets path name to 'name'.
1344 */
1345 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1346 u64 tree_id, u64 dirid, char *name)
1347 {
1348 struct btrfs_root *root;
1349 struct btrfs_key key;
1350 char *ptr;
1351 int ret = -1;
1352 int slot;
1353 int len;
1354 int total_len = 0;
1355 struct btrfs_inode_ref *iref;
1356 struct extent_buffer *l;
1357 struct btrfs_path *path;
1358
1359 if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1360 name[0]='\0';
1361 return 0;
1362 }
1363
1364 path = btrfs_alloc_path();
1365 if (!path)
1366 return -ENOMEM;
1367
1368 ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1369
1370 key.objectid = tree_id;
1371 key.type = BTRFS_ROOT_ITEM_KEY;
1372 key.offset = (u64)-1;
1373 root = btrfs_read_fs_root_no_name(info, &key);
1374 if (IS_ERR(root)) {
1375 printk(KERN_ERR "could not find root %llu\n", tree_id);
1376 ret = -ENOENT;
1377 goto out;
1378 }
1379
1380 key.objectid = dirid;
1381 key.type = BTRFS_INODE_REF_KEY;
1382 key.offset = (u64)-1;
1383
1384 while(1) {
1385 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1386 if (ret < 0)
1387 goto out;
1388
1389 l = path->nodes[0];
1390 slot = path->slots[0];
1391 if (ret > 0 && slot > 0)
1392 slot--;
1393 btrfs_item_key_to_cpu(l, &key, slot);
1394
1395 if (ret > 0 && (key.objectid != dirid ||
1396 key.type != BTRFS_INODE_REF_KEY)) {
1397 ret = -ENOENT;
1398 goto out;
1399 }
1400
1401 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1402 len = btrfs_inode_ref_name_len(l, iref);
1403 ptr -= len + 1;
1404 total_len += len + 1;
1405 if (ptr < name)
1406 goto out;
1407
1408 *(ptr + len) = '/';
1409 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1410
1411 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1412 break;
1413
1414 btrfs_release_path(root, path);
1415 key.objectid = key.offset;
1416 key.offset = (u64)-1;
1417 dirid = key.objectid;
1418
1419 }
1420 if (ptr < name)
1421 goto out;
1422 memcpy(name, ptr, total_len);
1423 name[total_len]='\0';
1424 ret = 0;
1425 out:
1426 btrfs_free_path(path);
1427 return ret;
1428 }
1429
1430 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1431 void __user *argp)
1432 {
1433 struct btrfs_ioctl_ino_lookup_args *args;
1434 struct inode *inode;
1435 int ret;
1436
1437 if (!capable(CAP_SYS_ADMIN))
1438 return -EPERM;
1439
1440 args = memdup_user(argp, sizeof(*args));
1441 if (IS_ERR(args))
1442 return PTR_ERR(args);
1443
1444 inode = fdentry(file)->d_inode;
1445
1446 if (args->treeid == 0)
1447 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
1448
1449 ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
1450 args->treeid, args->objectid,
1451 args->name);
1452
1453 if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1454 ret = -EFAULT;
1455
1456 kfree(args);
1457 return ret;
1458 }
1459
1460 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
1461 void __user *arg)
1462 {
1463 struct dentry *parent = fdentry(file);
1464 struct dentry *dentry;
1465 struct inode *dir = parent->d_inode;
1466 struct inode *inode;
1467 struct btrfs_root *root = BTRFS_I(dir)->root;
1468 struct btrfs_root *dest = NULL;
1469 struct btrfs_ioctl_vol_args *vol_args;
1470 struct btrfs_trans_handle *trans;
1471 int namelen;
1472 int ret;
1473 int err = 0;
1474
1475 vol_args = memdup_user(arg, sizeof(*vol_args));
1476 if (IS_ERR(vol_args))
1477 return PTR_ERR(vol_args);
1478
1479 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1480 namelen = strlen(vol_args->name);
1481 if (strchr(vol_args->name, '/') ||
1482 strncmp(vol_args->name, "..", namelen) == 0) {
1483 err = -EINVAL;
1484 goto out;
1485 }
1486
1487 err = mnt_want_write(file->f_path.mnt);
1488 if (err)
1489 goto out;
1490
1491 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
1492 dentry = lookup_one_len(vol_args->name, parent, namelen);
1493 if (IS_ERR(dentry)) {
1494 err = PTR_ERR(dentry);
1495 goto out_unlock_dir;
1496 }
1497
1498 if (!dentry->d_inode) {
1499 err = -ENOENT;
1500 goto out_dput;
1501 }
1502
1503 inode = dentry->d_inode;
1504 dest = BTRFS_I(inode)->root;
1505 if (!capable(CAP_SYS_ADMIN)){
1506 /*
1507 * Regular user. Only allow this with a special mount
1508 * option, when the user has write+exec access to the
1509 * subvol root, and when rmdir(2) would have been
1510 * allowed.
1511 *
1512 * Note that this is _not_ check that the subvol is
1513 * empty or doesn't contain data that we wouldn't
1514 * otherwise be able to delete.
1515 *
1516 * Users who want to delete empty subvols should try
1517 * rmdir(2).
1518 */
1519 err = -EPERM;
1520 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1521 goto out_dput;
1522
1523 /*
1524 * Do not allow deletion if the parent dir is the same
1525 * as the dir to be deleted. That means the ioctl
1526 * must be called on the dentry referencing the root
1527 * of the subvol, not a random directory contained
1528 * within it.
1529 */
1530 err = -EINVAL;
1531 if (root == dest)
1532 goto out_dput;
1533
1534 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
1535 if (err)
1536 goto out_dput;
1537
1538 /* check if subvolume may be deleted by a non-root user */
1539 err = btrfs_may_delete(dir, dentry, 1);
1540 if (err)
1541 goto out_dput;
1542 }
1543
1544 if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) {
1545 err = -EINVAL;
1546 goto out_dput;
1547 }
1548
1549 mutex_lock(&inode->i_mutex);
1550 err = d_invalidate(dentry);
1551 if (err)
1552 goto out_unlock;
1553
1554 down_write(&root->fs_info->subvol_sem);
1555
1556 err = may_destroy_subvol(dest);
1557 if (err)
1558 goto out_up_write;
1559
1560 trans = btrfs_start_transaction(root, 0);
1561 if (IS_ERR(trans)) {
1562 err = PTR_ERR(trans);
1563 goto out_up_write;
1564 }
1565 trans->block_rsv = &root->fs_info->global_block_rsv;
1566
1567 ret = btrfs_unlink_subvol(trans, root, dir,
1568 dest->root_key.objectid,
1569 dentry->d_name.name,
1570 dentry->d_name.len);
1571 BUG_ON(ret);
1572
1573 btrfs_record_root_in_trans(trans, dest);
1574
1575 memset(&dest->root_item.drop_progress, 0,
1576 sizeof(dest->root_item.drop_progress));
1577 dest->root_item.drop_level = 0;
1578 btrfs_set_root_refs(&dest->root_item, 0);
1579
1580 if (!xchg(&dest->orphan_item_inserted, 1)) {
1581 ret = btrfs_insert_orphan_item(trans,
1582 root->fs_info->tree_root,
1583 dest->root_key.objectid);
1584 BUG_ON(ret);
1585 }
1586
1587 ret = btrfs_end_transaction(trans, root);
1588 BUG_ON(ret);
1589 inode->i_flags |= S_DEAD;
1590 out_up_write:
1591 up_write(&root->fs_info->subvol_sem);
1592 out_unlock:
1593 mutex_unlock(&inode->i_mutex);
1594 if (!err) {
1595 shrink_dcache_sb(root->fs_info->sb);
1596 btrfs_invalidate_inodes(dest);
1597 d_delete(dentry);
1598 }
1599 out_dput:
1600 dput(dentry);
1601 out_unlock_dir:
1602 mutex_unlock(&dir->i_mutex);
1603 mnt_drop_write(file->f_path.mnt);
1604 out:
1605 kfree(vol_args);
1606 return err;
1607 }
1608
1609 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
1610 {
1611 struct inode *inode = fdentry(file)->d_inode;
1612 struct btrfs_root *root = BTRFS_I(inode)->root;
1613 struct btrfs_ioctl_defrag_range_args *range;
1614 int ret;
1615
1616 if (btrfs_root_readonly(root))
1617 return -EROFS;
1618
1619 ret = mnt_want_write(file->f_path.mnt);
1620 if (ret)
1621 return ret;
1622
1623 switch (inode->i_mode & S_IFMT) {
1624 case S_IFDIR:
1625 if (!capable(CAP_SYS_ADMIN)) {
1626 ret = -EPERM;
1627 goto out;
1628 }
1629 ret = btrfs_defrag_root(root, 0);
1630 if (ret)
1631 goto out;
1632 ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
1633 break;
1634 case S_IFREG:
1635 if (!(file->f_mode & FMODE_WRITE)) {
1636 ret = -EINVAL;
1637 goto out;
1638 }
1639
1640 range = kzalloc(sizeof(*range), GFP_KERNEL);
1641 if (!range) {
1642 ret = -ENOMEM;
1643 goto out;
1644 }
1645
1646 if (argp) {
1647 if (copy_from_user(range, argp,
1648 sizeof(*range))) {
1649 ret = -EFAULT;
1650 kfree(range);
1651 goto out;
1652 }
1653 /* compression requires us to start the IO */
1654 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1655 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
1656 range->extent_thresh = (u32)-1;
1657 }
1658 } else {
1659 /* the rest are all set to zero by kzalloc */
1660 range->len = (u64)-1;
1661 }
1662 ret = btrfs_defrag_file(file, range);
1663 kfree(range);
1664 break;
1665 default:
1666 ret = -EINVAL;
1667 }
1668 out:
1669 mnt_drop_write(file->f_path.mnt);
1670 return ret;
1671 }
1672
1673 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
1674 {
1675 struct btrfs_ioctl_vol_args *vol_args;
1676 int ret;
1677
1678 if (!capable(CAP_SYS_ADMIN))
1679 return -EPERM;
1680
1681 vol_args = memdup_user(arg, sizeof(*vol_args));
1682 if (IS_ERR(vol_args))
1683 return PTR_ERR(vol_args);
1684
1685 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1686 ret = btrfs_init_new_device(root, vol_args->name);
1687
1688 kfree(vol_args);
1689 return ret;
1690 }
1691
1692 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
1693 {
1694 struct btrfs_ioctl_vol_args *vol_args;
1695 int ret;
1696
1697 if (!capable(CAP_SYS_ADMIN))
1698 return -EPERM;
1699
1700 if (root->fs_info->sb->s_flags & MS_RDONLY)
1701 return -EROFS;
1702
1703 vol_args = memdup_user(arg, sizeof(*vol_args));
1704 if (IS_ERR(vol_args))
1705 return PTR_ERR(vol_args);
1706
1707 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1708 ret = btrfs_rm_device(root, vol_args->name);
1709
1710 kfree(vol_args);
1711 return ret;
1712 }
1713
1714 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
1715 u64 off, u64 olen, u64 destoff)
1716 {
1717 struct inode *inode = fdentry(file)->d_inode;
1718 struct btrfs_root *root = BTRFS_I(inode)->root;
1719 struct file *src_file;
1720 struct inode *src;
1721 struct btrfs_trans_handle *trans;
1722 struct btrfs_path *path;
1723 struct extent_buffer *leaf;
1724 char *buf;
1725 struct btrfs_key key;
1726 u32 nritems;
1727 int slot;
1728 int ret;
1729 u64 len = olen;
1730 u64 bs = root->fs_info->sb->s_blocksize;
1731 u64 hint_byte;
1732
1733 /*
1734 * TODO:
1735 * - split compressed inline extents. annoying: we need to
1736 * decompress into destination's address_space (the file offset
1737 * may change, so source mapping won't do), then recompress (or
1738 * otherwise reinsert) a subrange.
1739 * - allow ranges within the same file to be cloned (provided
1740 * they don't overlap)?
1741 */
1742
1743 /* the destination must be opened for writing */
1744 if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
1745 return -EINVAL;
1746
1747 if (btrfs_root_readonly(root))
1748 return -EROFS;
1749
1750 ret = mnt_want_write(file->f_path.mnt);
1751 if (ret)
1752 return ret;
1753
1754 src_file = fget(srcfd);
1755 if (!src_file) {
1756 ret = -EBADF;
1757 goto out_drop_write;
1758 }
1759
1760 src = src_file->f_dentry->d_inode;
1761
1762 ret = -EINVAL;
1763 if (src == inode)
1764 goto out_fput;
1765
1766 /* the src must be open for reading */
1767 if (!(src_file->f_mode & FMODE_READ))
1768 goto out_fput;
1769
1770 ret = -EISDIR;
1771 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
1772 goto out_fput;
1773
1774 ret = -EXDEV;
1775 if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
1776 goto out_fput;
1777
1778 ret = -ENOMEM;
1779 buf = vmalloc(btrfs_level_size(root, 0));
1780 if (!buf)
1781 goto out_fput;
1782
1783 path = btrfs_alloc_path();
1784 if (!path) {
1785 vfree(buf);
1786 goto out_fput;
1787 }
1788 path->reada = 2;
1789
1790 if (inode < src) {
1791 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
1792 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
1793 } else {
1794 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
1795 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
1796 }
1797
1798 /* determine range to clone */
1799 ret = -EINVAL;
1800 if (off + len > src->i_size || off + len < off)
1801 goto out_unlock;
1802 if (len == 0)
1803 olen = len = src->i_size - off;
1804 /* if we extend to eof, continue to block boundary */
1805 if (off + len == src->i_size)
1806 len = ALIGN(src->i_size, bs) - off;
1807
1808 /* verify the end result is block aligned */
1809 if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
1810 !IS_ALIGNED(destoff, bs))
1811 goto out_unlock;
1812
1813 /* do any pending delalloc/csum calc on src, one way or
1814 another, and lock file content */
1815 while (1) {
1816 struct btrfs_ordered_extent *ordered;
1817 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1818 ordered = btrfs_lookup_first_ordered_extent(src, off+len);
1819 if (!ordered &&
1820 !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len,
1821 EXTENT_DELALLOC, 0, NULL))
1822 break;
1823 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1824 if (ordered)
1825 btrfs_put_ordered_extent(ordered);
1826 btrfs_wait_ordered_range(src, off, len);
1827 }
1828
1829 /* clone data */
1830 key.objectid = src->i_ino;
1831 key.type = BTRFS_EXTENT_DATA_KEY;
1832 key.offset = 0;
1833
1834 while (1) {
1835 /*
1836 * note the key will change type as we walk through the
1837 * tree.
1838 */
1839 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1840 if (ret < 0)
1841 goto out;
1842
1843 nritems = btrfs_header_nritems(path->nodes[0]);
1844 if (path->slots[0] >= nritems) {
1845 ret = btrfs_next_leaf(root, path);
1846 if (ret < 0)
1847 goto out;
1848 if (ret > 0)
1849 break;
1850 nritems = btrfs_header_nritems(path->nodes[0]);
1851 }
1852 leaf = path->nodes[0];
1853 slot = path->slots[0];
1854
1855 btrfs_item_key_to_cpu(leaf, &key, slot);
1856 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
1857 key.objectid != src->i_ino)
1858 break;
1859
1860 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
1861 struct btrfs_file_extent_item *extent;
1862 int type;
1863 u32 size;
1864 struct btrfs_key new_key;
1865 u64 disko = 0, diskl = 0;
1866 u64 datao = 0, datal = 0;
1867 u8 comp;
1868 u64 endoff;
1869
1870 size = btrfs_item_size_nr(leaf, slot);
1871 read_extent_buffer(leaf, buf,
1872 btrfs_item_ptr_offset(leaf, slot),
1873 size);
1874
1875 extent = btrfs_item_ptr(leaf, slot,
1876 struct btrfs_file_extent_item);
1877 comp = btrfs_file_extent_compression(leaf, extent);
1878 type = btrfs_file_extent_type(leaf, extent);
1879 if (type == BTRFS_FILE_EXTENT_REG ||
1880 type == BTRFS_FILE_EXTENT_PREALLOC) {
1881 disko = btrfs_file_extent_disk_bytenr(leaf,
1882 extent);
1883 diskl = btrfs_file_extent_disk_num_bytes(leaf,
1884 extent);
1885 datao = btrfs_file_extent_offset(leaf, extent);
1886 datal = btrfs_file_extent_num_bytes(leaf,
1887 extent);
1888 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1889 /* take upper bound, may be compressed */
1890 datal = btrfs_file_extent_ram_bytes(leaf,
1891 extent);
1892 }
1893 btrfs_release_path(root, path);
1894
1895 if (key.offset + datal <= off ||
1896 key.offset >= off+len)
1897 goto next;
1898
1899 memcpy(&new_key, &key, sizeof(new_key));
1900 new_key.objectid = inode->i_ino;
1901 new_key.offset = key.offset + destoff - off;
1902
1903 trans = btrfs_start_transaction(root, 1);
1904 if (IS_ERR(trans)) {
1905 ret = PTR_ERR(trans);
1906 goto out;
1907 }
1908
1909 if (type == BTRFS_FILE_EXTENT_REG ||
1910 type == BTRFS_FILE_EXTENT_PREALLOC) {
1911 if (off > key.offset) {
1912 datao += off - key.offset;
1913 datal -= off - key.offset;
1914 }
1915
1916 if (key.offset + datal > off + len)
1917 datal = off + len - key.offset;
1918
1919 ret = btrfs_drop_extents(trans, inode,
1920 new_key.offset,
1921 new_key.offset + datal,
1922 &hint_byte, 1);
1923 BUG_ON(ret);
1924
1925 ret = btrfs_insert_empty_item(trans, root, path,
1926 &new_key, size);
1927 BUG_ON(ret);
1928
1929 leaf = path->nodes[0];
1930 slot = path->slots[0];
1931 write_extent_buffer(leaf, buf,
1932 btrfs_item_ptr_offset(leaf, slot),
1933 size);
1934
1935 extent = btrfs_item_ptr(leaf, slot,
1936 struct btrfs_file_extent_item);
1937
1938 /* disko == 0 means it's a hole */
1939 if (!disko)
1940 datao = 0;
1941
1942 btrfs_set_file_extent_offset(leaf, extent,
1943 datao);
1944 btrfs_set_file_extent_num_bytes(leaf, extent,
1945 datal);
1946 if (disko) {
1947 inode_add_bytes(inode, datal);
1948 ret = btrfs_inc_extent_ref(trans, root,
1949 disko, diskl, 0,
1950 root->root_key.objectid,
1951 inode->i_ino,
1952 new_key.offset - datao);
1953 BUG_ON(ret);
1954 }
1955 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1956 u64 skip = 0;
1957 u64 trim = 0;
1958 if (off > key.offset) {
1959 skip = off - key.offset;
1960 new_key.offset += skip;
1961 }
1962
1963 if (key.offset + datal > off+len)
1964 trim = key.offset + datal - (off+len);
1965
1966 if (comp && (skip || trim)) {
1967 ret = -EINVAL;
1968 btrfs_end_transaction(trans, root);
1969 goto out;
1970 }
1971 size -= skip + trim;
1972 datal -= skip + trim;
1973
1974 ret = btrfs_drop_extents(trans, inode,
1975 new_key.offset,
1976 new_key.offset + datal,
1977 &hint_byte, 1);
1978 BUG_ON(ret);
1979
1980 ret = btrfs_insert_empty_item(trans, root, path,
1981 &new_key, size);
1982 BUG_ON(ret);
1983
1984 if (skip) {
1985 u32 start =
1986 btrfs_file_extent_calc_inline_size(0);
1987 memmove(buf+start, buf+start+skip,
1988 datal);
1989 }
1990
1991 leaf = path->nodes[0];
1992 slot = path->slots[0];
1993 write_extent_buffer(leaf, buf,
1994 btrfs_item_ptr_offset(leaf, slot),
1995 size);
1996 inode_add_bytes(inode, datal);
1997 }
1998
1999 btrfs_mark_buffer_dirty(leaf);
2000 btrfs_release_path(root, path);
2001
2002 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2003
2004 /*
2005 * we round up to the block size at eof when
2006 * determining which extents to clone above,
2007 * but shouldn't round up the file size
2008 */
2009 endoff = new_key.offset + datal;
2010 if (endoff > destoff+olen)
2011 endoff = destoff+olen;
2012 if (endoff > inode->i_size)
2013 btrfs_i_size_write(inode, endoff);
2014
2015 BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
2016 ret = btrfs_update_inode(trans, root, inode);
2017 BUG_ON(ret);
2018 btrfs_end_transaction(trans, root);
2019 }
2020 next:
2021 btrfs_release_path(root, path);
2022 key.offset++;
2023 }
2024 ret = 0;
2025 out:
2026 btrfs_release_path(root, path);
2027 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2028 out_unlock:
2029 mutex_unlock(&src->i_mutex);
2030 mutex_unlock(&inode->i_mutex);
2031 vfree(buf);
2032 btrfs_free_path(path);
2033 out_fput:
2034 fput(src_file);
2035 out_drop_write:
2036 mnt_drop_write(file->f_path.mnt);
2037 return ret;
2038 }
2039
2040 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2041 {
2042 struct btrfs_ioctl_clone_range_args args;
2043
2044 if (copy_from_user(&args, argp, sizeof(args)))
2045 return -EFAULT;
2046 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2047 args.src_length, args.dest_offset);
2048 }
2049
2050 /*
2051 * there are many ways the trans_start and trans_end ioctls can lead
2052 * to deadlocks. They should only be used by applications that
2053 * basically own the machine, and have a very in depth understanding
2054 * of all the possible deadlocks and enospc problems.
2055 */
2056 static long btrfs_ioctl_trans_start(struct file *file)
2057 {
2058 struct inode *inode = fdentry(file)->d_inode;
2059 struct btrfs_root *root = BTRFS_I(inode)->root;
2060 struct btrfs_trans_handle *trans;
2061 int ret;
2062
2063 ret = -EPERM;
2064 if (!capable(CAP_SYS_ADMIN))
2065 goto out;
2066
2067 ret = -EINPROGRESS;
2068 if (file->private_data)
2069 goto out;
2070
2071 ret = -EROFS;
2072 if (btrfs_root_readonly(root))
2073 goto out;
2074
2075 ret = mnt_want_write(file->f_path.mnt);
2076 if (ret)
2077 goto out;
2078
2079 mutex_lock(&root->fs_info->trans_mutex);
2080 root->fs_info->open_ioctl_trans++;
2081 mutex_unlock(&root->fs_info->trans_mutex);
2082
2083 ret = -ENOMEM;
2084 trans = btrfs_start_ioctl_transaction(root, 0);
2085 if (!trans)
2086 goto out_drop;
2087
2088 file->private_data = trans;
2089 return 0;
2090
2091 out_drop:
2092 mutex_lock(&root->fs_info->trans_mutex);
2093 root->fs_info->open_ioctl_trans--;
2094 mutex_unlock(&root->fs_info->trans_mutex);
2095 mnt_drop_write(file->f_path.mnt);
2096 out:
2097 return ret;
2098 }
2099
2100 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2101 {
2102 struct inode *inode = fdentry(file)->d_inode;
2103 struct btrfs_root *root = BTRFS_I(inode)->root;
2104 struct btrfs_root *new_root;
2105 struct btrfs_dir_item *di;
2106 struct btrfs_trans_handle *trans;
2107 struct btrfs_path *path;
2108 struct btrfs_key location;
2109 struct btrfs_disk_key disk_key;
2110 struct btrfs_super_block *disk_super;
2111 u64 features;
2112 u64 objectid = 0;
2113 u64 dir_id;
2114
2115 if (!capable(CAP_SYS_ADMIN))
2116 return -EPERM;
2117
2118 if (copy_from_user(&objectid, argp, sizeof(objectid)))
2119 return -EFAULT;
2120
2121 if (!objectid)
2122 objectid = root->root_key.objectid;
2123
2124 location.objectid = objectid;
2125 location.type = BTRFS_ROOT_ITEM_KEY;
2126 location.offset = (u64)-1;
2127
2128 new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2129 if (IS_ERR(new_root))
2130 return PTR_ERR(new_root);
2131
2132 if (btrfs_root_refs(&new_root->root_item) == 0)
2133 return -ENOENT;
2134
2135 path = btrfs_alloc_path();
2136 if (!path)
2137 return -ENOMEM;
2138 path->leave_spinning = 1;
2139
2140 trans = btrfs_start_transaction(root, 1);
2141 if (!trans) {
2142 btrfs_free_path(path);
2143 return -ENOMEM;
2144 }
2145
2146 dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
2147 di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2148 dir_id, "default", 7, 1);
2149 if (IS_ERR_OR_NULL(di)) {
2150 btrfs_free_path(path);
2151 btrfs_end_transaction(trans, root);
2152 printk(KERN_ERR "Umm, you don't have the default dir item, "
2153 "this isn't going to work\n");
2154 return -ENOENT;
2155 }
2156
2157 btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2158 btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2159 btrfs_mark_buffer_dirty(path->nodes[0]);
2160 btrfs_free_path(path);
2161
2162 disk_super = &root->fs_info->super_copy;
2163 features = btrfs_super_incompat_flags(disk_super);
2164 if (!(features & BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)) {
2165 features |= BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL;
2166 btrfs_set_super_incompat_flags(disk_super, features);
2167 }
2168 btrfs_end_transaction(trans, root);
2169
2170 return 0;
2171 }
2172
2173 static void get_block_group_info(struct list_head *groups_list,
2174 struct btrfs_ioctl_space_info *space)
2175 {
2176 struct btrfs_block_group_cache *block_group;
2177
2178 space->total_bytes = 0;
2179 space->used_bytes = 0;
2180 space->flags = 0;
2181 list_for_each_entry(block_group, groups_list, list) {
2182 space->flags = block_group->flags;
2183 space->total_bytes += block_group->key.offset;
2184 space->used_bytes +=
2185 btrfs_block_group_used(&block_group->item);
2186 }
2187 }
2188
2189 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
2190 {
2191 struct btrfs_ioctl_space_args space_args;
2192 struct btrfs_ioctl_space_info space;
2193 struct btrfs_ioctl_space_info *dest;
2194 struct btrfs_ioctl_space_info *dest_orig;
2195 struct btrfs_ioctl_space_info *user_dest;
2196 struct btrfs_space_info *info;
2197 u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2198 BTRFS_BLOCK_GROUP_SYSTEM,
2199 BTRFS_BLOCK_GROUP_METADATA,
2200 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2201 int num_types = 4;
2202 int alloc_size;
2203 int ret = 0;
2204 int slot_count = 0;
2205 int i, c;
2206
2207 if (copy_from_user(&space_args,
2208 (struct btrfs_ioctl_space_args __user *)arg,
2209 sizeof(space_args)))
2210 return -EFAULT;
2211
2212 for (i = 0; i < num_types; i++) {
2213 struct btrfs_space_info *tmp;
2214
2215 info = NULL;
2216 rcu_read_lock();
2217 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2218 list) {
2219 if (tmp->flags == types[i]) {
2220 info = tmp;
2221 break;
2222 }
2223 }
2224 rcu_read_unlock();
2225
2226 if (!info)
2227 continue;
2228
2229 down_read(&info->groups_sem);
2230 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2231 if (!list_empty(&info->block_groups[c]))
2232 slot_count++;
2233 }
2234 up_read(&info->groups_sem);
2235 }
2236
2237 /* space_slots == 0 means they are asking for a count */
2238 if (space_args.space_slots == 0) {
2239 space_args.total_spaces = slot_count;
2240 goto out;
2241 }
2242
2243 slot_count = min_t(int, space_args.space_slots, slot_count);
2244
2245 alloc_size = sizeof(*dest) * slot_count;
2246
2247 /* we generally have at most 6 or so space infos, one for each raid
2248 * level. So, a whole page should be more than enough for everyone
2249 */
2250 if (alloc_size > PAGE_CACHE_SIZE)
2251 return -ENOMEM;
2252
2253 space_args.total_spaces = 0;
2254 dest = kmalloc(alloc_size, GFP_NOFS);
2255 if (!dest)
2256 return -ENOMEM;
2257 dest_orig = dest;
2258
2259 /* now we have a buffer to copy into */
2260 for (i = 0; i < num_types; i++) {
2261 struct btrfs_space_info *tmp;
2262
2263 info = NULL;
2264 rcu_read_lock();
2265 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2266 list) {
2267 if (tmp->flags == types[i]) {
2268 info = tmp;
2269 break;
2270 }
2271 }
2272 rcu_read_unlock();
2273
2274 if (!info)
2275 continue;
2276 down_read(&info->groups_sem);
2277 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2278 if (!list_empty(&info->block_groups[c])) {
2279 get_block_group_info(&info->block_groups[c],
2280 &space);
2281 memcpy(dest, &space, sizeof(space));
2282 dest++;
2283 space_args.total_spaces++;
2284 }
2285 }
2286 up_read(&info->groups_sem);
2287 }
2288
2289 user_dest = (struct btrfs_ioctl_space_info *)
2290 (arg + sizeof(struct btrfs_ioctl_space_args));
2291
2292 if (copy_to_user(user_dest, dest_orig, alloc_size))
2293 ret = -EFAULT;
2294
2295 kfree(dest_orig);
2296 out:
2297 if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
2298 ret = -EFAULT;
2299
2300 return ret;
2301 }
2302
2303 /*
2304 * there are many ways the trans_start and trans_end ioctls can lead
2305 * to deadlocks. They should only be used by applications that
2306 * basically own the machine, and have a very in depth understanding
2307 * of all the possible deadlocks and enospc problems.
2308 */
2309 long btrfs_ioctl_trans_end(struct file *file)
2310 {
2311 struct inode *inode = fdentry(file)->d_inode;
2312 struct btrfs_root *root = BTRFS_I(inode)->root;
2313 struct btrfs_trans_handle *trans;
2314
2315 trans = file->private_data;
2316 if (!trans)
2317 return -EINVAL;
2318 file->private_data = NULL;
2319
2320 btrfs_end_transaction(trans, root);
2321
2322 mutex_lock(&root->fs_info->trans_mutex);
2323 root->fs_info->open_ioctl_trans--;
2324 mutex_unlock(&root->fs_info->trans_mutex);
2325
2326 mnt_drop_write(file->f_path.mnt);
2327 return 0;
2328 }
2329
2330 static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp)
2331 {
2332 struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2333 struct btrfs_trans_handle *trans;
2334 u64 transid;
2335
2336 trans = btrfs_start_transaction(root, 0);
2337 transid = trans->transid;
2338 btrfs_commit_transaction_async(trans, root, 0);
2339
2340 if (argp)
2341 if (copy_to_user(argp, &transid, sizeof(transid)))
2342 return -EFAULT;
2343 return 0;
2344 }
2345
2346 static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp)
2347 {
2348 struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2349 u64 transid;
2350
2351 if (argp) {
2352 if (copy_from_user(&transid, argp, sizeof(transid)))
2353 return -EFAULT;
2354 } else {
2355 transid = 0; /* current trans */
2356 }
2357 return btrfs_wait_for_commit(root, transid);
2358 }
2359
2360 long btrfs_ioctl(struct file *file, unsigned int
2361 cmd, unsigned long arg)
2362 {
2363 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2364 void __user *argp = (void __user *)arg;
2365
2366 switch (cmd) {
2367 case FS_IOC_GETFLAGS:
2368 return btrfs_ioctl_getflags(file, argp);
2369 case FS_IOC_SETFLAGS:
2370 return btrfs_ioctl_setflags(file, argp);
2371 case FS_IOC_GETVERSION:
2372 return btrfs_ioctl_getversion(file, argp);
2373 case BTRFS_IOC_SNAP_CREATE:
2374 return btrfs_ioctl_snap_create(file, argp, 0);
2375 case BTRFS_IOC_SNAP_CREATE_V2:
2376 return btrfs_ioctl_snap_create_v2(file, argp, 0);
2377 case BTRFS_IOC_SUBVOL_CREATE:
2378 return btrfs_ioctl_snap_create(file, argp, 1);
2379 case BTRFS_IOC_SNAP_DESTROY:
2380 return btrfs_ioctl_snap_destroy(file, argp);
2381 case BTRFS_IOC_SUBVOL_GETFLAGS:
2382 return btrfs_ioctl_subvol_getflags(file, argp);
2383 case BTRFS_IOC_SUBVOL_SETFLAGS:
2384 return btrfs_ioctl_subvol_setflags(file, argp);
2385 case BTRFS_IOC_DEFAULT_SUBVOL:
2386 return btrfs_ioctl_default_subvol(file, argp);
2387 case BTRFS_IOC_DEFRAG:
2388 return btrfs_ioctl_defrag(file, NULL);
2389 case BTRFS_IOC_DEFRAG_RANGE:
2390 return btrfs_ioctl_defrag(file, argp);
2391 case BTRFS_IOC_RESIZE:
2392 return btrfs_ioctl_resize(root, argp);
2393 case BTRFS_IOC_ADD_DEV:
2394 return btrfs_ioctl_add_dev(root, argp);
2395 case BTRFS_IOC_RM_DEV:
2396 return btrfs_ioctl_rm_dev(root, argp);
2397 case BTRFS_IOC_BALANCE:
2398 return btrfs_balance(root->fs_info->dev_root);
2399 case BTRFS_IOC_CLONE:
2400 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
2401 case BTRFS_IOC_CLONE_RANGE:
2402 return btrfs_ioctl_clone_range(file, argp);
2403 case BTRFS_IOC_TRANS_START:
2404 return btrfs_ioctl_trans_start(file);
2405 case BTRFS_IOC_TRANS_END:
2406 return btrfs_ioctl_trans_end(file);
2407 case BTRFS_IOC_TREE_SEARCH:
2408 return btrfs_ioctl_tree_search(file, argp);
2409 case BTRFS_IOC_INO_LOOKUP:
2410 return btrfs_ioctl_ino_lookup(file, argp);
2411 case BTRFS_IOC_SPACE_INFO:
2412 return btrfs_ioctl_space_info(root, argp);
2413 case BTRFS_IOC_SYNC:
2414 btrfs_sync_fs(file->f_dentry->d_sb, 1);
2415 return 0;
2416 case BTRFS_IOC_START_SYNC:
2417 return btrfs_ioctl_start_sync(file, argp);
2418 case BTRFS_IOC_WAIT_SYNC:
2419 return btrfs_ioctl_wait_sync(file, argp);
2420 }
2421
2422 return -ENOTTY;
2423 }
Linux kernel - Deliverables
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