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Btrfs: Add BTRFS_IOC_SUBVOL_GETFLAGS/SETFLAGS ioctls
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / btrfs / ioctl.c
blobad1983524f97d7d97de7c5cafc6934736187fb72
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 unsigned long last_index;
647 unsigned long ra_pages = root->fs_info->bdi.ra_pages;
648 unsigned long total_read = 0;
649 u64 page_start;
650 u64 page_end;
651 u64 last_len = 0;
652 u64 skip = 0;
653 u64 defrag_end = 0;
654 unsigned long i;
655 int ret;
656
657 if (inode->i_size == 0)
658 return 0;
659
660 if (range->start + range->len > range->start) {
661 last_index = min_t(u64, inode->i_size - 1,
662 range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
663 } else {
664 last_index = (inode->i_size - 1) >> PAGE_CACHE_SHIFT;
665 }
666
667 i = range->start >> PAGE_CACHE_SHIFT;
668 while (i <= last_index) {
669 if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
670 PAGE_CACHE_SIZE,
671 range->extent_thresh,
672 &last_len, &skip,
673 &defrag_end)) {
674 unsigned long next;
675 /*
676 * the should_defrag function tells us how much to skip
677 * bump our counter by the suggested amount
678 */
679 next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
680 i = max(i + 1, next);
681 continue;
682 }
683
684 if (total_read % ra_pages == 0) {
685 btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
686 min(last_index, i + ra_pages - 1));
687 }
688 total_read++;
689 mutex_lock(&inode->i_mutex);
690 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
691 BTRFS_I(inode)->force_compress = 1;
692
693 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
694 if (ret)
695 goto err_unlock;
696 again:
697 if (inode->i_size == 0 ||
698 i > ((inode->i_size - 1) >> PAGE_CACHE_SHIFT)) {
699 ret = 0;
700 goto err_reservations;
701 }
702
703 page = grab_cache_page(inode->i_mapping, i);
704 if (!page) {
705 ret = -ENOMEM;
706 goto err_reservations;
707 }
708
709 if (!PageUptodate(page)) {
710 btrfs_readpage(NULL, page);
711 lock_page(page);
712 if (!PageUptodate(page)) {
713 unlock_page(page);
714 page_cache_release(page);
715 ret = -EIO;
716 goto err_reservations;
717 }
718 }
719
720 if (page->mapping != inode->i_mapping) {
721 unlock_page(page);
722 page_cache_release(page);
723 goto again;
724 }
725
726 wait_on_page_writeback(page);
727
728 if (PageDirty(page)) {
729 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
730 goto loop_unlock;
731 }
732
733 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
734 page_end = page_start + PAGE_CACHE_SIZE - 1;
735 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
736
737 ordered = btrfs_lookup_ordered_extent(inode, page_start);
738 if (ordered) {
739 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
740 unlock_page(page);
741 page_cache_release(page);
742 btrfs_start_ordered_extent(inode, ordered, 1);
743 btrfs_put_ordered_extent(ordered);
744 goto again;
745 }
746 set_page_extent_mapped(page);
747
748 /*
749 * this makes sure page_mkwrite is called on the
750 * page if it is dirtied again later
751 */
752 clear_page_dirty_for_io(page);
753 clear_extent_bits(&BTRFS_I(inode)->io_tree, page_start,
754 page_end, EXTENT_DIRTY | EXTENT_DELALLOC |
755 EXTENT_DO_ACCOUNTING, GFP_NOFS);
756
757 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
758 ClearPageChecked(page);
759 set_page_dirty(page);
760 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
761
762 loop_unlock:
763 unlock_page(page);
764 page_cache_release(page);
765 mutex_unlock(&inode->i_mutex);
766
767 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
768 i++;
769 }
770
771 if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
772 filemap_flush(inode->i_mapping);
773
774 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
775 /* the filemap_flush will queue IO into the worker threads, but
776 * we have to make sure the IO is actually started and that
777 * ordered extents get created before we return
778 */
779 atomic_inc(&root->fs_info->async_submit_draining);
780 while (atomic_read(&root->fs_info->nr_async_submits) ||
781 atomic_read(&root->fs_info->async_delalloc_pages)) {
782 wait_event(root->fs_info->async_submit_wait,
783 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
784 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
785 }
786 atomic_dec(&root->fs_info->async_submit_draining);
787
788 mutex_lock(&inode->i_mutex);
789 BTRFS_I(inode)->force_compress = 0;
790 mutex_unlock(&inode->i_mutex);
791 }
792
793 return 0;
794
795 err_reservations:
796 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
797 err_unlock:
798 mutex_unlock(&inode->i_mutex);
799 return ret;
800 }
801
802 static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
803 void __user *arg)
804 {
805 u64 new_size;
806 u64 old_size;
807 u64 devid = 1;
808 struct btrfs_ioctl_vol_args *vol_args;
809 struct btrfs_trans_handle *trans;
810 struct btrfs_device *device = NULL;
811 char *sizestr;
812 char *devstr = NULL;
813 int ret = 0;
814 int mod = 0;
815
816 if (root->fs_info->sb->s_flags & MS_RDONLY)
817 return -EROFS;
818
819 if (!capable(CAP_SYS_ADMIN))
820 return -EPERM;
821
822 vol_args = memdup_user(arg, sizeof(*vol_args));
823 if (IS_ERR(vol_args))
824 return PTR_ERR(vol_args);
825
826 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
827
828 mutex_lock(&root->fs_info->volume_mutex);
829 sizestr = vol_args->name;
830 devstr = strchr(sizestr, ':');
831 if (devstr) {
832 char *end;
833 sizestr = devstr + 1;
834 *devstr = '\0';
835 devstr = vol_args->name;
836 devid = simple_strtoull(devstr, &end, 10);
837 printk(KERN_INFO "resizing devid %llu\n",
838 (unsigned long long)devid);
839 }
840 device = btrfs_find_device(root, devid, NULL, NULL);
841 if (!device) {
842 printk(KERN_INFO "resizer unable to find device %llu\n",
843 (unsigned long long)devid);
844 ret = -EINVAL;
845 goto out_unlock;
846 }
847 if (!strcmp(sizestr, "max"))
848 new_size = device->bdev->bd_inode->i_size;
849 else {
850 if (sizestr[0] == '-') {
851 mod = -1;
852 sizestr++;
853 } else if (sizestr[0] == '+') {
854 mod = 1;
855 sizestr++;
856 }
857 new_size = memparse(sizestr, NULL);
858 if (new_size == 0) {
859 ret = -EINVAL;
860 goto out_unlock;
861 }
862 }
863
864 old_size = device->total_bytes;
865
866 if (mod < 0) {
867 if (new_size > old_size) {
868 ret = -EINVAL;
869 goto out_unlock;
870 }
871 new_size = old_size - new_size;
872 } else if (mod > 0) {
873 new_size = old_size + new_size;
874 }
875
876 if (new_size < 256 * 1024 * 1024) {
877 ret = -EINVAL;
878 goto out_unlock;
879 }
880 if (new_size > device->bdev->bd_inode->i_size) {
881 ret = -EFBIG;
882 goto out_unlock;
883 }
884
885 do_div(new_size, root->sectorsize);
886 new_size *= root->sectorsize;
887
888 printk(KERN_INFO "new size for %s is %llu\n",
889 device->name, (unsigned long long)new_size);
890
891 if (new_size > old_size) {
892 trans = btrfs_start_transaction(root, 0);
893 ret = btrfs_grow_device(trans, device, new_size);
894 btrfs_commit_transaction(trans, root);
895 } else {
896 ret = btrfs_shrink_device(device, new_size);
897 }
898
899 out_unlock:
900 mutex_unlock(&root->fs_info->volume_mutex);
901 kfree(vol_args);
902 return ret;
903 }
904
905 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
906 char *name,
907 unsigned long fd,
908 int subvol,
909 u64 *transid,
910 bool readonly)
911 {
912 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
913 struct file *src_file;
914 int namelen;
915 int ret = 0;
916
917 if (root->fs_info->sb->s_flags & MS_RDONLY)
918 return -EROFS;
919
920 namelen = strlen(name);
921 if (strchr(name, '/')) {
922 ret = -EINVAL;
923 goto out;
924 }
925
926 if (subvol) {
927 ret = btrfs_mksubvol(&file->f_path, name, namelen,
928 NULL, transid, readonly);
929 } else {
930 struct inode *src_inode;
931 src_file = fget(fd);
932 if (!src_file) {
933 ret = -EINVAL;
934 goto out;
935 }
936
937 src_inode = src_file->f_path.dentry->d_inode;
938 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
939 printk(KERN_INFO "btrfs: Snapshot src from "
940 "another FS\n");
941 ret = -EINVAL;
942 fput(src_file);
943 goto out;
944 }
945 ret = btrfs_mksubvol(&file->f_path, name, namelen,
946 BTRFS_I(src_inode)->root,
947 transid, readonly);
948 fput(src_file);
949 }
950 out:
951 return ret;
952 }
953
954 static noinline int btrfs_ioctl_snap_create(struct file *file,
955 void __user *arg, int subvol)
956 {
957 struct btrfs_ioctl_vol_args *vol_args;
958 int ret;
959
960 vol_args = memdup_user(arg, sizeof(*vol_args));
961 if (IS_ERR(vol_args))
962 return PTR_ERR(vol_args);
963 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
964
965 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
966 vol_args->fd, subvol,
967 NULL, false);
968
969 kfree(vol_args);
970 return ret;
971 }
972
973 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
974 void __user *arg, int subvol)
975 {
976 struct btrfs_ioctl_vol_args_v2 *vol_args;
977 int ret;
978 u64 transid = 0;
979 u64 *ptr = NULL;
980 bool readonly = false;
981
982 vol_args = memdup_user(arg, sizeof(*vol_args));
983 if (IS_ERR(vol_args))
984 return PTR_ERR(vol_args);
985 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
986
987 if (vol_args->flags &
988 ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY)) {
989 ret = -EOPNOTSUPP;
990 goto out;
991 }
992
993 if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
994 ptr = &transid;
995 if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
996 readonly = true;
997
998 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
999 vol_args->fd, subvol,
1000 ptr, readonly);
1001
1002 if (ret == 0 && ptr &&
1003 copy_to_user(arg +
1004 offsetof(struct btrfs_ioctl_vol_args_v2,
1005 transid), ptr, sizeof(*ptr)))
1006 ret = -EFAULT;
1007 out:
1008 kfree(vol_args);
1009 return ret;
1010 }
1011
1012 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1013 void __user *arg)
1014 {
1015 struct inode *inode = fdentry(file)->d_inode;
1016 struct btrfs_root *root = BTRFS_I(inode)->root;
1017 int ret = 0;
1018 u64 flags = 0;
1019
1020 if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID)
1021 return -EINVAL;
1022
1023 down_read(&root->fs_info->subvol_sem);
1024 if (btrfs_root_readonly(root))
1025 flags |= BTRFS_SUBVOL_RDONLY;
1026 up_read(&root->fs_info->subvol_sem);
1027
1028 if (copy_to_user(arg, &flags, sizeof(flags)))
1029 ret = -EFAULT;
1030
1031 return ret;
1032 }
1033
1034 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1035 void __user *arg)
1036 {
1037 struct inode *inode = fdentry(file)->d_inode;
1038 struct btrfs_root *root = BTRFS_I(inode)->root;
1039 struct btrfs_trans_handle *trans;
1040 u64 root_flags;
1041 u64 flags;
1042 int ret = 0;
1043
1044 if (root->fs_info->sb->s_flags & MS_RDONLY)
1045 return -EROFS;
1046
1047 if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID)
1048 return -EINVAL;
1049
1050 if (copy_from_user(&flags, arg, sizeof(flags)))
1051 return -EFAULT;
1052
1053 if (flags & ~BTRFS_SUBVOL_CREATE_ASYNC)
1054 return -EINVAL;
1055
1056 if (flags & ~BTRFS_SUBVOL_RDONLY)
1057 return -EOPNOTSUPP;
1058
1059 down_write(&root->fs_info->subvol_sem);
1060
1061 /* nothing to do */
1062 if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1063 goto out;
1064
1065 root_flags = btrfs_root_flags(&root->root_item);
1066 if (flags & BTRFS_SUBVOL_RDONLY)
1067 btrfs_set_root_flags(&root->root_item,
1068 root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1069 else
1070 btrfs_set_root_flags(&root->root_item,
1071 root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1072
1073 trans = btrfs_start_transaction(root, 1);
1074 if (IS_ERR(trans)) {
1075 ret = PTR_ERR(trans);
1076 goto out_reset;
1077 }
1078
1079 ret = btrfs_update_root(trans, root,
1080 &root->root_key, &root->root_item);
1081
1082 btrfs_commit_transaction(trans, root);
1083 out_reset:
1084 if (ret)
1085 btrfs_set_root_flags(&root->root_item, root_flags);
1086 out:
1087 up_write(&root->fs_info->subvol_sem);
1088 return ret;
1089 }
1090
1091 /*
1092 * helper to check if the subvolume references other subvolumes
1093 */
1094 static noinline int may_destroy_subvol(struct btrfs_root *root)
1095 {
1096 struct btrfs_path *path;
1097 struct btrfs_key key;
1098 int ret;
1099
1100 path = btrfs_alloc_path();
1101 if (!path)
1102 return -ENOMEM;
1103
1104 key.objectid = root->root_key.objectid;
1105 key.type = BTRFS_ROOT_REF_KEY;
1106 key.offset = (u64)-1;
1107
1108 ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1109 &key, path, 0, 0);
1110 if (ret < 0)
1111 goto out;
1112 BUG_ON(ret == 0);
1113
1114 ret = 0;
1115 if (path->slots[0] > 0) {
1116 path->slots[0]--;
1117 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1118 if (key.objectid == root->root_key.objectid &&
1119 key.type == BTRFS_ROOT_REF_KEY)
1120 ret = -ENOTEMPTY;
1121 }
1122 out:
1123 btrfs_free_path(path);
1124 return ret;
1125 }
1126
1127 static noinline int key_in_sk(struct btrfs_key *key,
1128 struct btrfs_ioctl_search_key *sk)
1129 {
1130 struct btrfs_key test;
1131 int ret;
1132
1133 test.objectid = sk->min_objectid;
1134 test.type = sk->min_type;
1135 test.offset = sk->min_offset;
1136
1137 ret = btrfs_comp_cpu_keys(key, &test);
1138 if (ret < 0)
1139 return 0;
1140
1141 test.objectid = sk->max_objectid;
1142 test.type = sk->max_type;
1143 test.offset = sk->max_offset;
1144
1145 ret = btrfs_comp_cpu_keys(key, &test);
1146 if (ret > 0)
1147 return 0;
1148 return 1;
1149 }
1150
1151 static noinline int copy_to_sk(struct btrfs_root *root,
1152 struct btrfs_path *path,
1153 struct btrfs_key *key,
1154 struct btrfs_ioctl_search_key *sk,
1155 char *buf,
1156 unsigned long *sk_offset,
1157 int *num_found)
1158 {
1159 u64 found_transid;
1160 struct extent_buffer *leaf;
1161 struct btrfs_ioctl_search_header sh;
1162 unsigned long item_off;
1163 unsigned long item_len;
1164 int nritems;
1165 int i;
1166 int slot;
1167 int found = 0;
1168 int ret = 0;
1169
1170 leaf = path->nodes[0];
1171 slot = path->slots[0];
1172 nritems = btrfs_header_nritems(leaf);
1173
1174 if (btrfs_header_generation(leaf) > sk->max_transid) {
1175 i = nritems;
1176 goto advance_key;
1177 }
1178 found_transid = btrfs_header_generation(leaf);
1179
1180 for (i = slot; i < nritems; i++) {
1181 item_off = btrfs_item_ptr_offset(leaf, i);
1182 item_len = btrfs_item_size_nr(leaf, i);
1183
1184 if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1185 item_len = 0;
1186
1187 if (sizeof(sh) + item_len + *sk_offset >
1188 BTRFS_SEARCH_ARGS_BUFSIZE) {
1189 ret = 1;
1190 goto overflow;
1191 }
1192
1193 btrfs_item_key_to_cpu(leaf, key, i);
1194 if (!key_in_sk(key, sk))
1195 continue;
1196
1197 sh.objectid = key->objectid;
1198 sh.offset = key->offset;
1199 sh.type = key->type;
1200 sh.len = item_len;
1201 sh.transid = found_transid;
1202
1203 /* copy search result header */
1204 memcpy(buf + *sk_offset, &sh, sizeof(sh));
1205 *sk_offset += sizeof(sh);
1206
1207 if (item_len) {
1208 char *p = buf + *sk_offset;
1209 /* copy the item */
1210 read_extent_buffer(leaf, p,
1211 item_off, item_len);
1212 *sk_offset += item_len;
1213 }
1214 found++;
1215
1216 if (*num_found >= sk->nr_items)
1217 break;
1218 }
1219 advance_key:
1220 ret = 0;
1221 if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1222 key->offset++;
1223 else if (key->type < (u8)-1 && key->type < sk->max_type) {
1224 key->offset = 0;
1225 key->type++;
1226 } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1227 key->offset = 0;
1228 key->type = 0;
1229 key->objectid++;
1230 } else
1231 ret = 1;
1232 overflow:
1233 *num_found += found;
1234 return ret;
1235 }
1236
1237 static noinline int search_ioctl(struct inode *inode,
1238 struct btrfs_ioctl_search_args *args)
1239 {
1240 struct btrfs_root *root;
1241 struct btrfs_key key;
1242 struct btrfs_key max_key;
1243 struct btrfs_path *path;
1244 struct btrfs_ioctl_search_key *sk = &args->key;
1245 struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1246 int ret;
1247 int num_found = 0;
1248 unsigned long sk_offset = 0;
1249
1250 path = btrfs_alloc_path();
1251 if (!path)
1252 return -ENOMEM;
1253
1254 if (sk->tree_id == 0) {
1255 /* search the root of the inode that was passed */
1256 root = BTRFS_I(inode)->root;
1257 } else {
1258 key.objectid = sk->tree_id;
1259 key.type = BTRFS_ROOT_ITEM_KEY;
1260 key.offset = (u64)-1;
1261 root = btrfs_read_fs_root_no_name(info, &key);
1262 if (IS_ERR(root)) {
1263 printk(KERN_ERR "could not find root %llu\n",
1264 sk->tree_id);
1265 btrfs_free_path(path);
1266 return -ENOENT;
1267 }
1268 }
1269
1270 key.objectid = sk->min_objectid;
1271 key.type = sk->min_type;
1272 key.offset = sk->min_offset;
1273
1274 max_key.objectid = sk->max_objectid;
1275 max_key.type = sk->max_type;
1276 max_key.offset = sk->max_offset;
1277
1278 path->keep_locks = 1;
1279
1280 while(1) {
1281 ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1282 sk->min_transid);
1283 if (ret != 0) {
1284 if (ret > 0)
1285 ret = 0;
1286 goto err;
1287 }
1288 ret = copy_to_sk(root, path, &key, sk, args->buf,
1289 &sk_offset, &num_found);
1290 btrfs_release_path(root, path);
1291 if (ret || num_found >= sk->nr_items)
1292 break;
1293
1294 }
1295 ret = 0;
1296 err:
1297 sk->nr_items = num_found;
1298 btrfs_free_path(path);
1299 return ret;
1300 }
1301
1302 static noinline int btrfs_ioctl_tree_search(struct file *file,
1303 void __user *argp)
1304 {
1305 struct btrfs_ioctl_search_args *args;
1306 struct inode *inode;
1307 int ret;
1308
1309 if (!capable(CAP_SYS_ADMIN))
1310 return -EPERM;
1311
1312 args = memdup_user(argp, sizeof(*args));
1313 if (IS_ERR(args))
1314 return PTR_ERR(args);
1315
1316 inode = fdentry(file)->d_inode;
1317 ret = search_ioctl(inode, args);
1318 if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1319 ret = -EFAULT;
1320 kfree(args);
1321 return ret;
1322 }
1323
1324 /*
1325 * Search INODE_REFs to identify path name of 'dirid' directory
1326 * in a 'tree_id' tree. and sets path name to 'name'.
1327 */
1328 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1329 u64 tree_id, u64 dirid, char *name)
1330 {
1331 struct btrfs_root *root;
1332 struct btrfs_key key;
1333 char *ptr;
1334 int ret = -1;
1335 int slot;
1336 int len;
1337 int total_len = 0;
1338 struct btrfs_inode_ref *iref;
1339 struct extent_buffer *l;
1340 struct btrfs_path *path;
1341
1342 if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1343 name[0]='\0';
1344 return 0;
1345 }
1346
1347 path = btrfs_alloc_path();
1348 if (!path)
1349 return -ENOMEM;
1350
1351 ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1352
1353 key.objectid = tree_id;
1354 key.type = BTRFS_ROOT_ITEM_KEY;
1355 key.offset = (u64)-1;
1356 root = btrfs_read_fs_root_no_name(info, &key);
1357 if (IS_ERR(root)) {
1358 printk(KERN_ERR "could not find root %llu\n", tree_id);
1359 ret = -ENOENT;
1360 goto out;
1361 }
1362
1363 key.objectid = dirid;
1364 key.type = BTRFS_INODE_REF_KEY;
1365 key.offset = (u64)-1;
1366
1367 while(1) {
1368 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1369 if (ret < 0)
1370 goto out;
1371
1372 l = path->nodes[0];
1373 slot = path->slots[0];
1374 if (ret > 0 && slot > 0)
1375 slot--;
1376 btrfs_item_key_to_cpu(l, &key, slot);
1377
1378 if (ret > 0 && (key.objectid != dirid ||
1379 key.type != BTRFS_INODE_REF_KEY)) {
1380 ret = -ENOENT;
1381 goto out;
1382 }
1383
1384 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1385 len = btrfs_inode_ref_name_len(l, iref);
1386 ptr -= len + 1;
1387 total_len += len + 1;
1388 if (ptr < name)
1389 goto out;
1390
1391 *(ptr + len) = '/';
1392 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1393
1394 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1395 break;
1396
1397 btrfs_release_path(root, path);
1398 key.objectid = key.offset;
1399 key.offset = (u64)-1;
1400 dirid = key.objectid;
1401
1402 }
1403 if (ptr < name)
1404 goto out;
1405 memcpy(name, ptr, total_len);
1406 name[total_len]='\0';
1407 ret = 0;
1408 out:
1409 btrfs_free_path(path);
1410 return ret;
1411 }
1412
1413 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1414 void __user *argp)
1415 {
1416 struct btrfs_ioctl_ino_lookup_args *args;
1417 struct inode *inode;
1418 int ret;
1419
1420 if (!capable(CAP_SYS_ADMIN))
1421 return -EPERM;
1422
1423 args = memdup_user(argp, sizeof(*args));
1424 if (IS_ERR(args))
1425 return PTR_ERR(args);
1426
1427 inode = fdentry(file)->d_inode;
1428
1429 if (args->treeid == 0)
1430 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
1431
1432 ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
1433 args->treeid, args->objectid,
1434 args->name);
1435
1436 if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1437 ret = -EFAULT;
1438
1439 kfree(args);
1440 return ret;
1441 }
1442
1443 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
1444 void __user *arg)
1445 {
1446 struct dentry *parent = fdentry(file);
1447 struct dentry *dentry;
1448 struct inode *dir = parent->d_inode;
1449 struct inode *inode;
1450 struct btrfs_root *root = BTRFS_I(dir)->root;
1451 struct btrfs_root *dest = NULL;
1452 struct btrfs_ioctl_vol_args *vol_args;
1453 struct btrfs_trans_handle *trans;
1454 int namelen;
1455 int ret;
1456 int err = 0;
1457
1458 vol_args = memdup_user(arg, sizeof(*vol_args));
1459 if (IS_ERR(vol_args))
1460 return PTR_ERR(vol_args);
1461
1462 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1463 namelen = strlen(vol_args->name);
1464 if (strchr(vol_args->name, '/') ||
1465 strncmp(vol_args->name, "..", namelen) == 0) {
1466 err = -EINVAL;
1467 goto out;
1468 }
1469
1470 err = mnt_want_write(file->f_path.mnt);
1471 if (err)
1472 goto out;
1473
1474 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
1475 dentry = lookup_one_len(vol_args->name, parent, namelen);
1476 if (IS_ERR(dentry)) {
1477 err = PTR_ERR(dentry);
1478 goto out_unlock_dir;
1479 }
1480
1481 if (!dentry->d_inode) {
1482 err = -ENOENT;
1483 goto out_dput;
1484 }
1485
1486 inode = dentry->d_inode;
1487 dest = BTRFS_I(inode)->root;
1488 if (!capable(CAP_SYS_ADMIN)){
1489 /*
1490 * Regular user. Only allow this with a special mount
1491 * option, when the user has write+exec access to the
1492 * subvol root, and when rmdir(2) would have been
1493 * allowed.
1494 *
1495 * Note that this is _not_ check that the subvol is
1496 * empty or doesn't contain data that we wouldn't
1497 * otherwise be able to delete.
1498 *
1499 * Users who want to delete empty subvols should try
1500 * rmdir(2).
1501 */
1502 err = -EPERM;
1503 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1504 goto out_dput;
1505
1506 /*
1507 * Do not allow deletion if the parent dir is the same
1508 * as the dir to be deleted. That means the ioctl
1509 * must be called on the dentry referencing the root
1510 * of the subvol, not a random directory contained
1511 * within it.
1512 */
1513 err = -EINVAL;
1514 if (root == dest)
1515 goto out_dput;
1516
1517 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
1518 if (err)
1519 goto out_dput;
1520
1521 /* check if subvolume may be deleted by a non-root user */
1522 err = btrfs_may_delete(dir, dentry, 1);
1523 if (err)
1524 goto out_dput;
1525 }
1526
1527 if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) {
1528 err = -EINVAL;
1529 goto out_dput;
1530 }
1531
1532 mutex_lock(&inode->i_mutex);
1533 err = d_invalidate(dentry);
1534 if (err)
1535 goto out_unlock;
1536
1537 down_write(&root->fs_info->subvol_sem);
1538
1539 err = may_destroy_subvol(dest);
1540 if (err)
1541 goto out_up_write;
1542
1543 trans = btrfs_start_transaction(root, 0);
1544 if (IS_ERR(trans)) {
1545 err = PTR_ERR(trans);
1546 goto out_up_write;
1547 }
1548 trans->block_rsv = &root->fs_info->global_block_rsv;
1549
1550 ret = btrfs_unlink_subvol(trans, root, dir,
1551 dest->root_key.objectid,
1552 dentry->d_name.name,
1553 dentry->d_name.len);
1554 BUG_ON(ret);
1555
1556 btrfs_record_root_in_trans(trans, dest);
1557
1558 memset(&dest->root_item.drop_progress, 0,
1559 sizeof(dest->root_item.drop_progress));
1560 dest->root_item.drop_level = 0;
1561 btrfs_set_root_refs(&dest->root_item, 0);
1562
1563 if (!xchg(&dest->orphan_item_inserted, 1)) {
1564 ret = btrfs_insert_orphan_item(trans,
1565 root->fs_info->tree_root,
1566 dest->root_key.objectid);
1567 BUG_ON(ret);
1568 }
1569
1570 ret = btrfs_end_transaction(trans, root);
1571 BUG_ON(ret);
1572 inode->i_flags |= S_DEAD;
1573 out_up_write:
1574 up_write(&root->fs_info->subvol_sem);
1575 out_unlock:
1576 mutex_unlock(&inode->i_mutex);
1577 if (!err) {
1578 shrink_dcache_sb(root->fs_info->sb);
1579 btrfs_invalidate_inodes(dest);
1580 d_delete(dentry);
1581 }
1582 out_dput:
1583 dput(dentry);
1584 out_unlock_dir:
1585 mutex_unlock(&dir->i_mutex);
1586 mnt_drop_write(file->f_path.mnt);
1587 out:
1588 kfree(vol_args);
1589 return err;
1590 }
1591
1592 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
1593 {
1594 struct inode *inode = fdentry(file)->d_inode;
1595 struct btrfs_root *root = BTRFS_I(inode)->root;
1596 struct btrfs_ioctl_defrag_range_args *range;
1597 int ret;
1598
1599 if (btrfs_root_readonly(root))
1600 return -EROFS;
1601
1602 ret = mnt_want_write(file->f_path.mnt);
1603 if (ret)
1604 return ret;
1605
1606 switch (inode->i_mode & S_IFMT) {
1607 case S_IFDIR:
1608 if (!capable(CAP_SYS_ADMIN)) {
1609 ret = -EPERM;
1610 goto out;
1611 }
1612 ret = btrfs_defrag_root(root, 0);
1613 if (ret)
1614 goto out;
1615 ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
1616 break;
1617 case S_IFREG:
1618 if (!(file->f_mode & FMODE_WRITE)) {
1619 ret = -EINVAL;
1620 goto out;
1621 }
1622
1623 range = kzalloc(sizeof(*range), GFP_KERNEL);
1624 if (!range) {
1625 ret = -ENOMEM;
1626 goto out;
1627 }
1628
1629 if (argp) {
1630 if (copy_from_user(range, argp,
1631 sizeof(*range))) {
1632 ret = -EFAULT;
1633 kfree(range);
1634 goto out;
1635 }
1636 /* compression requires us to start the IO */
1637 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1638 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
1639 range->extent_thresh = (u32)-1;
1640 }
1641 } else {
1642 /* the rest are all set to zero by kzalloc */
1643 range->len = (u64)-1;
1644 }
1645 ret = btrfs_defrag_file(file, range);
1646 kfree(range);
1647 break;
1648 default:
1649 ret = -EINVAL;
1650 }
1651 out:
1652 mnt_drop_write(file->f_path.mnt);
1653 return ret;
1654 }
1655
1656 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
1657 {
1658 struct btrfs_ioctl_vol_args *vol_args;
1659 int ret;
1660
1661 if (!capable(CAP_SYS_ADMIN))
1662 return -EPERM;
1663
1664 vol_args = memdup_user(arg, sizeof(*vol_args));
1665 if (IS_ERR(vol_args))
1666 return PTR_ERR(vol_args);
1667
1668 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1669 ret = btrfs_init_new_device(root, vol_args->name);
1670
1671 kfree(vol_args);
1672 return ret;
1673 }
1674
1675 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
1676 {
1677 struct btrfs_ioctl_vol_args *vol_args;
1678 int ret;
1679
1680 if (!capable(CAP_SYS_ADMIN))
1681 return -EPERM;
1682
1683 if (root->fs_info->sb->s_flags & MS_RDONLY)
1684 return -EROFS;
1685
1686 vol_args = memdup_user(arg, sizeof(*vol_args));
1687 if (IS_ERR(vol_args))
1688 return PTR_ERR(vol_args);
1689
1690 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1691 ret = btrfs_rm_device(root, vol_args->name);
1692
1693 kfree(vol_args);
1694 return ret;
1695 }
1696
1697 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
1698 u64 off, u64 olen, u64 destoff)
1699 {
1700 struct inode *inode = fdentry(file)->d_inode;
1701 struct btrfs_root *root = BTRFS_I(inode)->root;
1702 struct file *src_file;
1703 struct inode *src;
1704 struct btrfs_trans_handle *trans;
1705 struct btrfs_path *path;
1706 struct extent_buffer *leaf;
1707 char *buf;
1708 struct btrfs_key key;
1709 u32 nritems;
1710 int slot;
1711 int ret;
1712 u64 len = olen;
1713 u64 bs = root->fs_info->sb->s_blocksize;
1714 u64 hint_byte;
1715
1716 /*
1717 * TODO:
1718 * - split compressed inline extents. annoying: we need to
1719 * decompress into destination's address_space (the file offset
1720 * may change, so source mapping won't do), then recompress (or
1721 * otherwise reinsert) a subrange.
1722 * - allow ranges within the same file to be cloned (provided
1723 * they don't overlap)?
1724 */
1725
1726 /* the destination must be opened for writing */
1727 if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
1728 return -EINVAL;
1729
1730 if (btrfs_root_readonly(root))
1731 return -EROFS;
1732
1733 ret = mnt_want_write(file->f_path.mnt);
1734 if (ret)
1735 return ret;
1736
1737 src_file = fget(srcfd);
1738 if (!src_file) {
1739 ret = -EBADF;
1740 goto out_drop_write;
1741 }
1742
1743 src = src_file->f_dentry->d_inode;
1744
1745 ret = -EINVAL;
1746 if (src == inode)
1747 goto out_fput;
1748
1749 /* the src must be open for reading */
1750 if (!(src_file->f_mode & FMODE_READ))
1751 goto out_fput;
1752
1753 ret = -EISDIR;
1754 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
1755 goto out_fput;
1756
1757 ret = -EXDEV;
1758 if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
1759 goto out_fput;
1760
1761 ret = -ENOMEM;
1762 buf = vmalloc(btrfs_level_size(root, 0));
1763 if (!buf)
1764 goto out_fput;
1765
1766 path = btrfs_alloc_path();
1767 if (!path) {
1768 vfree(buf);
1769 goto out_fput;
1770 }
1771 path->reada = 2;
1772
1773 if (inode < src) {
1774 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
1775 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
1776 } else {
1777 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
1778 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
1779 }
1780
1781 /* determine range to clone */
1782 ret = -EINVAL;
1783 if (off + len > src->i_size || off + len < off)
1784 goto out_unlock;
1785 if (len == 0)
1786 olen = len = src->i_size - off;
1787 /* if we extend to eof, continue to block boundary */
1788 if (off + len == src->i_size)
1789 len = ALIGN(src->i_size, bs) - off;
1790
1791 /* verify the end result is block aligned */
1792 if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
1793 !IS_ALIGNED(destoff, bs))
1794 goto out_unlock;
1795
1796 /* do any pending delalloc/csum calc on src, one way or
1797 another, and lock file content */
1798 while (1) {
1799 struct btrfs_ordered_extent *ordered;
1800 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1801 ordered = btrfs_lookup_first_ordered_extent(src, off+len);
1802 if (!ordered &&
1803 !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len,
1804 EXTENT_DELALLOC, 0, NULL))
1805 break;
1806 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1807 if (ordered)
1808 btrfs_put_ordered_extent(ordered);
1809 btrfs_wait_ordered_range(src, off, len);
1810 }
1811
1812 /* clone data */
1813 key.objectid = src->i_ino;
1814 key.type = BTRFS_EXTENT_DATA_KEY;
1815 key.offset = 0;
1816
1817 while (1) {
1818 /*
1819 * note the key will change type as we walk through the
1820 * tree.
1821 */
1822 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1823 if (ret < 0)
1824 goto out;
1825
1826 nritems = btrfs_header_nritems(path->nodes[0]);
1827 if (path->slots[0] >= nritems) {
1828 ret = btrfs_next_leaf(root, path);
1829 if (ret < 0)
1830 goto out;
1831 if (ret > 0)
1832 break;
1833 nritems = btrfs_header_nritems(path->nodes[0]);
1834 }
1835 leaf = path->nodes[0];
1836 slot = path->slots[0];
1837
1838 btrfs_item_key_to_cpu(leaf, &key, slot);
1839 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
1840 key.objectid != src->i_ino)
1841 break;
1842
1843 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
1844 struct btrfs_file_extent_item *extent;
1845 int type;
1846 u32 size;
1847 struct btrfs_key new_key;
1848 u64 disko = 0, diskl = 0;
1849 u64 datao = 0, datal = 0;
1850 u8 comp;
1851 u64 endoff;
1852
1853 size = btrfs_item_size_nr(leaf, slot);
1854 read_extent_buffer(leaf, buf,
1855 btrfs_item_ptr_offset(leaf, slot),
1856 size);
1857
1858 extent = btrfs_item_ptr(leaf, slot,
1859 struct btrfs_file_extent_item);
1860 comp = btrfs_file_extent_compression(leaf, extent);
1861 type = btrfs_file_extent_type(leaf, extent);
1862 if (type == BTRFS_FILE_EXTENT_REG ||
1863 type == BTRFS_FILE_EXTENT_PREALLOC) {
1864 disko = btrfs_file_extent_disk_bytenr(leaf,
1865 extent);
1866 diskl = btrfs_file_extent_disk_num_bytes(leaf,
1867 extent);
1868 datao = btrfs_file_extent_offset(leaf, extent);
1869 datal = btrfs_file_extent_num_bytes(leaf,
1870 extent);
1871 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1872 /* take upper bound, may be compressed */
1873 datal = btrfs_file_extent_ram_bytes(leaf,
1874 extent);
1875 }
1876 btrfs_release_path(root, path);
1877
1878 if (key.offset + datal <= off ||
1879 key.offset >= off+len)
1880 goto next;
1881
1882 memcpy(&new_key, &key, sizeof(new_key));
1883 new_key.objectid = inode->i_ino;
1884 new_key.offset = key.offset + destoff - off;
1885
1886 trans = btrfs_start_transaction(root, 1);
1887 if (IS_ERR(trans)) {
1888 ret = PTR_ERR(trans);
1889 goto out;
1890 }
1891
1892 if (type == BTRFS_FILE_EXTENT_REG ||
1893 type == BTRFS_FILE_EXTENT_PREALLOC) {
1894 if (off > key.offset) {
1895 datao += off - key.offset;
1896 datal -= off - key.offset;
1897 }
1898
1899 if (key.offset + datal > off + len)
1900 datal = off + len - key.offset;
1901
1902 ret = btrfs_drop_extents(trans, inode,
1903 new_key.offset,
1904 new_key.offset + datal,
1905 &hint_byte, 1);
1906 BUG_ON(ret);
1907
1908 ret = btrfs_insert_empty_item(trans, root, path,
1909 &new_key, size);
1910 BUG_ON(ret);
1911
1912 leaf = path->nodes[0];
1913 slot = path->slots[0];
1914 write_extent_buffer(leaf, buf,
1915 btrfs_item_ptr_offset(leaf, slot),
1916 size);
1917
1918 extent = btrfs_item_ptr(leaf, slot,
1919 struct btrfs_file_extent_item);
1920
1921 /* disko == 0 means it's a hole */
1922 if (!disko)
1923 datao = 0;
1924
1925 btrfs_set_file_extent_offset(leaf, extent,
1926 datao);
1927 btrfs_set_file_extent_num_bytes(leaf, extent,
1928 datal);
1929 if (disko) {
1930 inode_add_bytes(inode, datal);
1931 ret = btrfs_inc_extent_ref(trans, root,
1932 disko, diskl, 0,
1933 root->root_key.objectid,
1934 inode->i_ino,
1935 new_key.offset - datao);
1936 BUG_ON(ret);
1937 }
1938 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1939 u64 skip = 0;
1940 u64 trim = 0;
1941 if (off > key.offset) {
1942 skip = off - key.offset;
1943 new_key.offset += skip;
1944 }
1945
1946 if (key.offset + datal > off+len)
1947 trim = key.offset + datal - (off+len);
1948
1949 if (comp && (skip || trim)) {
1950 ret = -EINVAL;
1951 btrfs_end_transaction(trans, root);
1952 goto out;
1953 }
1954 size -= skip + trim;
1955 datal -= skip + trim;
1956
1957 ret = btrfs_drop_extents(trans, inode,
1958 new_key.offset,
1959 new_key.offset + datal,
1960 &hint_byte, 1);
1961 BUG_ON(ret);
1962
1963 ret = btrfs_insert_empty_item(trans, root, path,
1964 &new_key, size);
1965 BUG_ON(ret);
1966
1967 if (skip) {
1968 u32 start =
1969 btrfs_file_extent_calc_inline_size(0);
1970 memmove(buf+start, buf+start+skip,
1971 datal);
1972 }
1973
1974 leaf = path->nodes[0];
1975 slot = path->slots[0];
1976 write_extent_buffer(leaf, buf,
1977 btrfs_item_ptr_offset(leaf, slot),
1978 size);
1979 inode_add_bytes(inode, datal);
1980 }
1981
1982 btrfs_mark_buffer_dirty(leaf);
1983 btrfs_release_path(root, path);
1984
1985 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1986
1987 /*
1988 * we round up to the block size at eof when
1989 * determining which extents to clone above,
1990 * but shouldn't round up the file size
1991 */
1992 endoff = new_key.offset + datal;
1993 if (endoff > destoff+olen)
1994 endoff = destoff+olen;
1995 if (endoff > inode->i_size)
1996 btrfs_i_size_write(inode, endoff);
1997
1998 BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
1999 ret = btrfs_update_inode(trans, root, inode);
2000 BUG_ON(ret);
2001 btrfs_end_transaction(trans, root);
2002 }
2003 next:
2004 btrfs_release_path(root, path);
2005 key.offset++;
2006 }
2007 ret = 0;
2008 out:
2009 btrfs_release_path(root, path);
2010 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2011 out_unlock:
2012 mutex_unlock(&src->i_mutex);
2013 mutex_unlock(&inode->i_mutex);
2014 vfree(buf);
2015 btrfs_free_path(path);
2016 out_fput:
2017 fput(src_file);
2018 out_drop_write:
2019 mnt_drop_write(file->f_path.mnt);
2020 return ret;
2021 }
2022
2023 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2024 {
2025 struct btrfs_ioctl_clone_range_args args;
2026
2027 if (copy_from_user(&args, argp, sizeof(args)))
2028 return -EFAULT;
2029 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2030 args.src_length, args.dest_offset);
2031 }
2032
2033 /*
2034 * there are many ways the trans_start and trans_end ioctls can lead
2035 * to deadlocks. They should only be used by applications that
2036 * basically own the machine, and have a very in depth understanding
2037 * of all the possible deadlocks and enospc problems.
2038 */
2039 static long btrfs_ioctl_trans_start(struct file *file)
2040 {
2041 struct inode *inode = fdentry(file)->d_inode;
2042 struct btrfs_root *root = BTRFS_I(inode)->root;
2043 struct btrfs_trans_handle *trans;
2044 int ret;
2045
2046 ret = -EPERM;
2047 if (!capable(CAP_SYS_ADMIN))
2048 goto out;
2049
2050 ret = -EINPROGRESS;
2051 if (file->private_data)
2052 goto out;
2053
2054 ret = -EROFS;
2055 if (btrfs_root_readonly(root))
2056 goto out;
2057
2058 ret = mnt_want_write(file->f_path.mnt);
2059 if (ret)
2060 goto out;
2061
2062 mutex_lock(&root->fs_info->trans_mutex);
2063 root->fs_info->open_ioctl_trans++;
2064 mutex_unlock(&root->fs_info->trans_mutex);
2065
2066 ret = -ENOMEM;
2067 trans = btrfs_start_ioctl_transaction(root, 0);
2068 if (!trans)
2069 goto out_drop;
2070
2071 file->private_data = trans;
2072 return 0;
2073
2074 out_drop:
2075 mutex_lock(&root->fs_info->trans_mutex);
2076 root->fs_info->open_ioctl_trans--;
2077 mutex_unlock(&root->fs_info->trans_mutex);
2078 mnt_drop_write(file->f_path.mnt);
2079 out:
2080 return ret;
2081 }
2082
2083 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2084 {
2085 struct inode *inode = fdentry(file)->d_inode;
2086 struct btrfs_root *root = BTRFS_I(inode)->root;
2087 struct btrfs_root *new_root;
2088 struct btrfs_dir_item *di;
2089 struct btrfs_trans_handle *trans;
2090 struct btrfs_path *path;
2091 struct btrfs_key location;
2092 struct btrfs_disk_key disk_key;
2093 struct btrfs_super_block *disk_super;
2094 u64 features;
2095 u64 objectid = 0;
2096 u64 dir_id;
2097
2098 if (!capable(CAP_SYS_ADMIN))
2099 return -EPERM;
2100
2101 if (copy_from_user(&objectid, argp, sizeof(objectid)))
2102 return -EFAULT;
2103
2104 if (!objectid)
2105 objectid = root->root_key.objectid;
2106
2107 location.objectid = objectid;
2108 location.type = BTRFS_ROOT_ITEM_KEY;
2109 location.offset = (u64)-1;
2110
2111 new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2112 if (IS_ERR(new_root))
2113 return PTR_ERR(new_root);
2114
2115 if (btrfs_root_refs(&new_root->root_item) == 0)
2116 return -ENOENT;
2117
2118 path = btrfs_alloc_path();
2119 if (!path)
2120 return -ENOMEM;
2121 path->leave_spinning = 1;
2122
2123 trans = btrfs_start_transaction(root, 1);
2124 if (!trans) {
2125 btrfs_free_path(path);
2126 return -ENOMEM;
2127 }
2128
2129 dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
2130 di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2131 dir_id, "default", 7, 1);
2132 if (IS_ERR_OR_NULL(di)) {
2133 btrfs_free_path(path);
2134 btrfs_end_transaction(trans, root);
2135 printk(KERN_ERR "Umm, you don't have the default dir item, "
2136 "this isn't going to work\n");
2137 return -ENOENT;
2138 }
2139
2140 btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2141 btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2142 btrfs_mark_buffer_dirty(path->nodes[0]);
2143 btrfs_free_path(path);
2144
2145 disk_super = &root->fs_info->super_copy;
2146 features = btrfs_super_incompat_flags(disk_super);
2147 if (!(features & BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)) {
2148 features |= BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL;
2149 btrfs_set_super_incompat_flags(disk_super, features);
2150 }
2151 btrfs_end_transaction(trans, root);
2152
2153 return 0;
2154 }
2155
2156 static void get_block_group_info(struct list_head *groups_list,
2157 struct btrfs_ioctl_space_info *space)
2158 {
2159 struct btrfs_block_group_cache *block_group;
2160
2161 space->total_bytes = 0;
2162 space->used_bytes = 0;
2163 space->flags = 0;
2164 list_for_each_entry(block_group, groups_list, list) {
2165 space->flags = block_group->flags;
2166 space->total_bytes += block_group->key.offset;
2167 space->used_bytes +=
2168 btrfs_block_group_used(&block_group->item);
2169 }
2170 }
2171
2172 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
2173 {
2174 struct btrfs_ioctl_space_args space_args;
2175 struct btrfs_ioctl_space_info space;
2176 struct btrfs_ioctl_space_info *dest;
2177 struct btrfs_ioctl_space_info *dest_orig;
2178 struct btrfs_ioctl_space_info *user_dest;
2179 struct btrfs_space_info *info;
2180 u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2181 BTRFS_BLOCK_GROUP_SYSTEM,
2182 BTRFS_BLOCK_GROUP_METADATA,
2183 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2184 int num_types = 4;
2185 int alloc_size;
2186 int ret = 0;
2187 int slot_count = 0;
2188 int i, c;
2189
2190 if (copy_from_user(&space_args,
2191 (struct btrfs_ioctl_space_args __user *)arg,
2192 sizeof(space_args)))
2193 return -EFAULT;
2194
2195 for (i = 0; i < num_types; i++) {
2196 struct btrfs_space_info *tmp;
2197
2198 info = NULL;
2199 rcu_read_lock();
2200 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2201 list) {
2202 if (tmp->flags == types[i]) {
2203 info = tmp;
2204 break;
2205 }
2206 }
2207 rcu_read_unlock();
2208
2209 if (!info)
2210 continue;
2211
2212 down_read(&info->groups_sem);
2213 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2214 if (!list_empty(&info->block_groups[c]))
2215 slot_count++;
2216 }
2217 up_read(&info->groups_sem);
2218 }
2219
2220 /* space_slots == 0 means they are asking for a count */
2221 if (space_args.space_slots == 0) {
2222 space_args.total_spaces = slot_count;
2223 goto out;
2224 }
2225
2226 slot_count = min_t(int, space_args.space_slots, slot_count);
2227
2228 alloc_size = sizeof(*dest) * slot_count;
2229
2230 /* we generally have at most 6 or so space infos, one for each raid
2231 * level. So, a whole page should be more than enough for everyone
2232 */
2233 if (alloc_size > PAGE_CACHE_SIZE)
2234 return -ENOMEM;
2235
2236 space_args.total_spaces = 0;
2237 dest = kmalloc(alloc_size, GFP_NOFS);
2238 if (!dest)
2239 return -ENOMEM;
2240 dest_orig = dest;
2241
2242 /* now we have a buffer to copy into */
2243 for (i = 0; i < num_types; i++) {
2244 struct btrfs_space_info *tmp;
2245
2246 info = NULL;
2247 rcu_read_lock();
2248 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2249 list) {
2250 if (tmp->flags == types[i]) {
2251 info = tmp;
2252 break;
2253 }
2254 }
2255 rcu_read_unlock();
2256
2257 if (!info)
2258 continue;
2259 down_read(&info->groups_sem);
2260 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2261 if (!list_empty(&info->block_groups[c])) {
2262 get_block_group_info(&info->block_groups[c],
2263 &space);
2264 memcpy(dest, &space, sizeof(space));
2265 dest++;
2266 space_args.total_spaces++;
2267 }
2268 }
2269 up_read(&info->groups_sem);
2270 }
2271
2272 user_dest = (struct btrfs_ioctl_space_info *)
2273 (arg + sizeof(struct btrfs_ioctl_space_args));
2274
2275 if (copy_to_user(user_dest, dest_orig, alloc_size))
2276 ret = -EFAULT;
2277
2278 kfree(dest_orig);
2279 out:
2280 if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
2281 ret = -EFAULT;
2282
2283 return ret;
2284 }
2285
2286 /*
2287 * there are many ways the trans_start and trans_end ioctls can lead
2288 * to deadlocks. They should only be used by applications that
2289 * basically own the machine, and have a very in depth understanding
2290 * of all the possible deadlocks and enospc problems.
2291 */
2292 long btrfs_ioctl_trans_end(struct file *file)
2293 {
2294 struct inode *inode = fdentry(file)->d_inode;
2295 struct btrfs_root *root = BTRFS_I(inode)->root;
2296 struct btrfs_trans_handle *trans;
2297
2298 trans = file->private_data;
2299 if (!trans)
2300 return -EINVAL;
2301 file->private_data = NULL;
2302
2303 btrfs_end_transaction(trans, root);
2304
2305 mutex_lock(&root->fs_info->trans_mutex);
2306 root->fs_info->open_ioctl_trans--;
2307 mutex_unlock(&root->fs_info->trans_mutex);
2308
2309 mnt_drop_write(file->f_path.mnt);
2310 return 0;
2311 }
2312
2313 static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp)
2314 {
2315 struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2316 struct btrfs_trans_handle *trans;
2317 u64 transid;
2318
2319 trans = btrfs_start_transaction(root, 0);
2320 transid = trans->transid;
2321 btrfs_commit_transaction_async(trans, root, 0);
2322
2323 if (argp)
2324 if (copy_to_user(argp, &transid, sizeof(transid)))
2325 return -EFAULT;
2326 return 0;
2327 }
2328
2329 static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp)
2330 {
2331 struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2332 u64 transid;
2333
2334 if (argp) {
2335 if (copy_from_user(&transid, argp, sizeof(transid)))
2336 return -EFAULT;
2337 } else {
2338 transid = 0; /* current trans */
2339 }
2340 return btrfs_wait_for_commit(root, transid);
2341 }
2342
2343 long btrfs_ioctl(struct file *file, unsigned int
2344 cmd, unsigned long arg)
2345 {
2346 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2347 void __user *argp = (void __user *)arg;
2348
2349 switch (cmd) {
2350 case FS_IOC_GETFLAGS:
2351 return btrfs_ioctl_getflags(file, argp);
2352 case FS_IOC_SETFLAGS:
2353 return btrfs_ioctl_setflags(file, argp);
2354 case FS_IOC_GETVERSION:
2355 return btrfs_ioctl_getversion(file, argp);
2356 case BTRFS_IOC_SNAP_CREATE:
2357 return btrfs_ioctl_snap_create(file, argp, 0);
2358 case BTRFS_IOC_SNAP_CREATE_V2:
2359 return btrfs_ioctl_snap_create_v2(file, argp, 0);
2360 case BTRFS_IOC_SUBVOL_CREATE:
2361 return btrfs_ioctl_snap_create(file, argp, 1);
2362 case BTRFS_IOC_SNAP_DESTROY:
2363 return btrfs_ioctl_snap_destroy(file, argp);
2364 case BTRFS_IOC_SUBVOL_GETFLAGS:
2365 return btrfs_ioctl_subvol_getflags(file, argp);
2366 case BTRFS_IOC_SUBVOL_SETFLAGS:
2367 return btrfs_ioctl_subvol_setflags(file, argp);
2368 case BTRFS_IOC_DEFAULT_SUBVOL:
2369 return btrfs_ioctl_default_subvol(file, argp);
2370 case BTRFS_IOC_DEFRAG:
2371 return btrfs_ioctl_defrag(file, NULL);
2372 case BTRFS_IOC_DEFRAG_RANGE:
2373 return btrfs_ioctl_defrag(file, argp);
2374 case BTRFS_IOC_RESIZE:
2375 return btrfs_ioctl_resize(root, argp);
2376 case BTRFS_IOC_ADD_DEV:
2377 return btrfs_ioctl_add_dev(root, argp);
2378 case BTRFS_IOC_RM_DEV:
2379 return btrfs_ioctl_rm_dev(root, argp);
2380 case BTRFS_IOC_BALANCE:
2381 return btrfs_balance(root->fs_info->dev_root);
2382 case BTRFS_IOC_CLONE:
2383 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
2384 case BTRFS_IOC_CLONE_RANGE:
2385 return btrfs_ioctl_clone_range(file, argp);
2386 case BTRFS_IOC_TRANS_START:
2387 return btrfs_ioctl_trans_start(file);
2388 case BTRFS_IOC_TRANS_END:
2389 return btrfs_ioctl_trans_end(file);
2390 case BTRFS_IOC_TREE_SEARCH:
2391 return btrfs_ioctl_tree_search(file, argp);
2392 case BTRFS_IOC_INO_LOOKUP:
2393 return btrfs_ioctl_ino_lookup(file, argp);
2394 case BTRFS_IOC_SPACE_INFO:
2395 return btrfs_ioctl_space_info(root, argp);
2396 case BTRFS_IOC_SYNC:
2397 btrfs_sync_fs(file->f_dentry->d_sb, 1);
2398 return 0;
2399 case BTRFS_IOC_START_SYNC:
2400 return btrfs_ioctl_start_sync(file, argp);
2401 case BTRFS_IOC_WAIT_SYNC:
2402 return btrfs_ioctl_wait_sync(file, argp);
2403 }
2404
2405 return -ENOTTY;
2406 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree