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