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ceph: fix debugfs entry, simplify fsid checks
[deliverable/linux.git] / fs / btrfs / ioctl.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/fsnotify.h>
25 #include <linux/pagemap.h>
26 #include <linux/highmem.h>
27 #include <linux/time.h>
28 #include <linux/init.h>
29 #include <linux/string.h>
30 #include <linux/backing-dev.h>
31 #include <linux/mount.h>
32 #include <linux/mpage.h>
33 #include <linux/namei.h>
34 #include <linux/swap.h>
35 #include <linux/writeback.h>
36 #include <linux/statfs.h>
37 #include <linux/compat.h>
38 #include <linux/bit_spinlock.h>
39 #include <linux/security.h>
40 #include <linux/xattr.h>
41 #include <linux/vmalloc.h>
42 #include "compat.h"
43 #include "ctree.h"
44 #include "disk-io.h"
45 #include "transaction.h"
46 #include "btrfs_inode.h"
47 #include "ioctl.h"
48 #include "print-tree.h"
49 #include "volumes.h"
50 #include "locking.h"
51
52 /* Mask out flags that are inappropriate for the given type of inode. */
53 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
54 {
55 if (S_ISDIR(mode))
56 return flags;
57 else if (S_ISREG(mode))
58 return flags & ~FS_DIRSYNC_FL;
59 else
60 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
61 }
62
63 /*
64 * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
65 */
66 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
67 {
68 unsigned int iflags = 0;
69
70 if (flags & BTRFS_INODE_SYNC)
71 iflags |= FS_SYNC_FL;
72 if (flags & BTRFS_INODE_IMMUTABLE)
73 iflags |= FS_IMMUTABLE_FL;
74 if (flags & BTRFS_INODE_APPEND)
75 iflags |= FS_APPEND_FL;
76 if (flags & BTRFS_INODE_NODUMP)
77 iflags |= FS_NODUMP_FL;
78 if (flags & BTRFS_INODE_NOATIME)
79 iflags |= FS_NOATIME_FL;
80 if (flags & BTRFS_INODE_DIRSYNC)
81 iflags |= FS_DIRSYNC_FL;
82
83 return iflags;
84 }
85
86 /*
87 * Update inode->i_flags based on the btrfs internal flags.
88 */
89 void btrfs_update_iflags(struct inode *inode)
90 {
91 struct btrfs_inode *ip = BTRFS_I(inode);
92
93 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
94
95 if (ip->flags & BTRFS_INODE_SYNC)
96 inode->i_flags |= S_SYNC;
97 if (ip->flags & BTRFS_INODE_IMMUTABLE)
98 inode->i_flags |= S_IMMUTABLE;
99 if (ip->flags & BTRFS_INODE_APPEND)
100 inode->i_flags |= S_APPEND;
101 if (ip->flags & BTRFS_INODE_NOATIME)
102 inode->i_flags |= S_NOATIME;
103 if (ip->flags & BTRFS_INODE_DIRSYNC)
104 inode->i_flags |= S_DIRSYNC;
105 }
106
107 /*
108 * Inherit flags from the parent inode.
109 *
110 * Unlike extN we don't have any flags we don't want to inherit currently.
111 */
112 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
113 {
114 unsigned int flags;
115
116 if (!dir)
117 return;
118
119 flags = BTRFS_I(dir)->flags;
120
121 if (S_ISREG(inode->i_mode))
122 flags &= ~BTRFS_INODE_DIRSYNC;
123 else if (!S_ISDIR(inode->i_mode))
124 flags &= (BTRFS_INODE_NODUMP | BTRFS_INODE_NOATIME);
125
126 BTRFS_I(inode)->flags = flags;
127 btrfs_update_iflags(inode);
128 }
129
130 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
131 {
132 struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode);
133 unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
134
135 if (copy_to_user(arg, &flags, sizeof(flags)))
136 return -EFAULT;
137 return 0;
138 }
139
140 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
141 {
142 struct inode *inode = file->f_path.dentry->d_inode;
143 struct btrfs_inode *ip = BTRFS_I(inode);
144 struct btrfs_root *root = ip->root;
145 struct btrfs_trans_handle *trans;
146 unsigned int flags, oldflags;
147 int ret;
148
149 if (copy_from_user(&flags, arg, sizeof(flags)))
150 return -EFAULT;
151
152 if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
153 FS_NOATIME_FL | FS_NODUMP_FL | \
154 FS_SYNC_FL | FS_DIRSYNC_FL))
155 return -EOPNOTSUPP;
156
157 if (!is_owner_or_cap(inode))
158 return -EACCES;
159
160 mutex_lock(&inode->i_mutex);
161
162 flags = btrfs_mask_flags(inode->i_mode, flags);
163 oldflags = btrfs_flags_to_ioctl(ip->flags);
164 if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
165 if (!capable(CAP_LINUX_IMMUTABLE)) {
166 ret = -EPERM;
167 goto out_unlock;
168 }
169 }
170
171 ret = mnt_want_write(file->f_path.mnt);
172 if (ret)
173 goto out_unlock;
174
175 if (flags & FS_SYNC_FL)
176 ip->flags |= BTRFS_INODE_SYNC;
177 else
178 ip->flags &= ~BTRFS_INODE_SYNC;
179 if (flags & FS_IMMUTABLE_FL)
180 ip->flags |= BTRFS_INODE_IMMUTABLE;
181 else
182 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
183 if (flags & FS_APPEND_FL)
184 ip->flags |= BTRFS_INODE_APPEND;
185 else
186 ip->flags &= ~BTRFS_INODE_APPEND;
187 if (flags & FS_NODUMP_FL)
188 ip->flags |= BTRFS_INODE_NODUMP;
189 else
190 ip->flags &= ~BTRFS_INODE_NODUMP;
191 if (flags & FS_NOATIME_FL)
192 ip->flags |= BTRFS_INODE_NOATIME;
193 else
194 ip->flags &= ~BTRFS_INODE_NOATIME;
195 if (flags & FS_DIRSYNC_FL)
196 ip->flags |= BTRFS_INODE_DIRSYNC;
197 else
198 ip->flags &= ~BTRFS_INODE_DIRSYNC;
199
200
201 trans = btrfs_join_transaction(root, 1);
202 BUG_ON(!trans);
203
204 ret = btrfs_update_inode(trans, root, inode);
205 BUG_ON(ret);
206
207 btrfs_update_iflags(inode);
208 inode->i_ctime = CURRENT_TIME;
209 btrfs_end_transaction(trans, root);
210
211 mnt_drop_write(file->f_path.mnt);
212 out_unlock:
213 mutex_unlock(&inode->i_mutex);
214 return 0;
215 }
216
217 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
218 {
219 struct inode *inode = file->f_path.dentry->d_inode;
220
221 return put_user(inode->i_generation, arg);
222 }
223
224 static noinline int create_subvol(struct btrfs_root *root,
225 struct dentry *dentry,
226 char *name, int namelen)
227 {
228 struct btrfs_trans_handle *trans;
229 struct btrfs_key key;
230 struct btrfs_root_item root_item;
231 struct btrfs_inode_item *inode_item;
232 struct extent_buffer *leaf;
233 struct btrfs_root *new_root;
234 struct inode *dir = dentry->d_parent->d_inode;
235 int ret;
236 int err;
237 u64 objectid;
238 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
239 u64 index = 0;
240 unsigned long nr = 1;
241
242 ret = btrfs_check_metadata_free_space(root);
243 if (ret)
244 return ret;
245
246 trans = btrfs_start_transaction(root, 1);
247 BUG_ON(!trans);
248
249 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
250 0, &objectid);
251 if (ret)
252 goto fail;
253
254 leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
255 0, objectid, NULL, 0, 0, 0);
256 if (IS_ERR(leaf)) {
257 ret = PTR_ERR(leaf);
258 goto fail;
259 }
260
261 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
262 btrfs_set_header_bytenr(leaf, leaf->start);
263 btrfs_set_header_generation(leaf, trans->transid);
264 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
265 btrfs_set_header_owner(leaf, objectid);
266
267 write_extent_buffer(leaf, root->fs_info->fsid,
268 (unsigned long)btrfs_header_fsid(leaf),
269 BTRFS_FSID_SIZE);
270 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
271 (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
272 BTRFS_UUID_SIZE);
273 btrfs_mark_buffer_dirty(leaf);
274
275 inode_item = &root_item.inode;
276 memset(inode_item, 0, sizeof(*inode_item));
277 inode_item->generation = cpu_to_le64(1);
278 inode_item->size = cpu_to_le64(3);
279 inode_item->nlink = cpu_to_le32(1);
280 inode_item->nbytes = cpu_to_le64(root->leafsize);
281 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
282
283 btrfs_set_root_bytenr(&root_item, leaf->start);
284 btrfs_set_root_generation(&root_item, trans->transid);
285 btrfs_set_root_level(&root_item, 0);
286 btrfs_set_root_refs(&root_item, 1);
287 btrfs_set_root_used(&root_item, 0);
288 btrfs_set_root_last_snapshot(&root_item, 0);
289
290 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
291 root_item.drop_level = 0;
292
293 btrfs_tree_unlock(leaf);
294 free_extent_buffer(leaf);
295 leaf = NULL;
296
297 btrfs_set_root_dirid(&root_item, new_dirid);
298
299 key.objectid = objectid;
300 key.offset = 0;
301 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
302 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
303 &root_item);
304 if (ret)
305 goto fail;
306
307 key.offset = (u64)-1;
308 new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
309 BUG_ON(IS_ERR(new_root));
310
311 btrfs_record_root_in_trans(trans, new_root);
312
313 ret = btrfs_create_subvol_root(trans, new_root, new_dirid,
314 BTRFS_I(dir)->block_group);
315 /*
316 * insert the directory item
317 */
318 ret = btrfs_set_inode_index(dir, &index);
319 BUG_ON(ret);
320
321 ret = btrfs_insert_dir_item(trans, root,
322 name, namelen, dir->i_ino, &key,
323 BTRFS_FT_DIR, index);
324 if (ret)
325 goto fail;
326
327 btrfs_i_size_write(dir, dir->i_size + namelen * 2);
328 ret = btrfs_update_inode(trans, root, dir);
329 BUG_ON(ret);
330
331 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
332 objectid, root->root_key.objectid,
333 dir->i_ino, index, name, namelen);
334
335 BUG_ON(ret);
336
337 d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
338 fail:
339 nr = trans->blocks_used;
340 err = btrfs_commit_transaction(trans, root);
341 if (err && !ret)
342 ret = err;
343 return ret;
344 }
345
346 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
347 char *name, int namelen)
348 {
349 struct btrfs_pending_snapshot *pending_snapshot;
350 struct btrfs_trans_handle *trans;
351 int ret = 0;
352 int err;
353 unsigned long nr = 0;
354
355 if (!root->ref_cows)
356 return -EINVAL;
357
358 ret = btrfs_check_metadata_free_space(root);
359 if (ret)
360 goto fail_unlock;
361
362 pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
363 if (!pending_snapshot) {
364 ret = -ENOMEM;
365 goto fail_unlock;
366 }
367 pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
368 if (!pending_snapshot->name) {
369 ret = -ENOMEM;
370 kfree(pending_snapshot);
371 goto fail_unlock;
372 }
373 memcpy(pending_snapshot->name, name, namelen);
374 pending_snapshot->name[namelen] = '\0';
375 pending_snapshot->dentry = dentry;
376 trans = btrfs_start_transaction(root, 1);
377 BUG_ON(!trans);
378 pending_snapshot->root = root;
379 list_add(&pending_snapshot->list,
380 &trans->transaction->pending_snapshots);
381 err = btrfs_commit_transaction(trans, root);
382
383 fail_unlock:
384 btrfs_btree_balance_dirty(root, nr);
385 return ret;
386 }
387
388 /* copy of may_create in fs/namei.c() */
389 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
390 {
391 if (child->d_inode)
392 return -EEXIST;
393 if (IS_DEADDIR(dir))
394 return -ENOENT;
395 return inode_permission(dir, MAY_WRITE | MAY_EXEC);
396 }
397
398 /*
399 * Create a new subvolume below @parent. This is largely modeled after
400 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
401 * inside this filesystem so it's quite a bit simpler.
402 */
403 static noinline int btrfs_mksubvol(struct path *parent,
404 char *name, int namelen,
405 struct btrfs_root *snap_src)
406 {
407 struct inode *dir = parent->dentry->d_inode;
408 struct dentry *dentry;
409 int error;
410
411 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
412
413 dentry = lookup_one_len(name, parent->dentry, namelen);
414 error = PTR_ERR(dentry);
415 if (IS_ERR(dentry))
416 goto out_unlock;
417
418 error = -EEXIST;
419 if (dentry->d_inode)
420 goto out_dput;
421
422 error = mnt_want_write(parent->mnt);
423 if (error)
424 goto out_dput;
425
426 error = btrfs_may_create(dir, dentry);
427 if (error)
428 goto out_drop_write;
429
430 down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
431
432 if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
433 goto out_up_read;
434
435 if (snap_src) {
436 error = create_snapshot(snap_src, dentry,
437 name, namelen);
438 } else {
439 error = create_subvol(BTRFS_I(dir)->root, dentry,
440 name, namelen);
441 }
442 if (!error)
443 fsnotify_mkdir(dir, dentry);
444 out_up_read:
445 up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
446 out_drop_write:
447 mnt_drop_write(parent->mnt);
448 out_dput:
449 dput(dentry);
450 out_unlock:
451 mutex_unlock(&dir->i_mutex);
452 return error;
453 }
454
455 static int btrfs_defrag_file(struct file *file)
456 {
457 struct inode *inode = fdentry(file)->d_inode;
458 struct btrfs_root *root = BTRFS_I(inode)->root;
459 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
460 struct btrfs_ordered_extent *ordered;
461 struct page *page;
462 unsigned long last_index;
463 unsigned long ra_pages = root->fs_info->bdi.ra_pages;
464 unsigned long total_read = 0;
465 u64 page_start;
466 u64 page_end;
467 unsigned long i;
468 int ret;
469
470 ret = btrfs_check_data_free_space(root, inode, inode->i_size);
471 if (ret)
472 return -ENOSPC;
473
474 mutex_lock(&inode->i_mutex);
475 last_index = inode->i_size >> PAGE_CACHE_SHIFT;
476 for (i = 0; i <= last_index; i++) {
477 if (total_read % ra_pages == 0) {
478 btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
479 min(last_index, i + ra_pages - 1));
480 }
481 total_read++;
482 again:
483 page = grab_cache_page(inode->i_mapping, i);
484 if (!page)
485 goto out_unlock;
486 if (!PageUptodate(page)) {
487 btrfs_readpage(NULL, page);
488 lock_page(page);
489 if (!PageUptodate(page)) {
490 unlock_page(page);
491 page_cache_release(page);
492 goto out_unlock;
493 }
494 }
495
496 wait_on_page_writeback(page);
497
498 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
499 page_end = page_start + PAGE_CACHE_SIZE - 1;
500 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
501
502 ordered = btrfs_lookup_ordered_extent(inode, page_start);
503 if (ordered) {
504 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
505 unlock_page(page);
506 page_cache_release(page);
507 btrfs_start_ordered_extent(inode, ordered, 1);
508 btrfs_put_ordered_extent(ordered);
509 goto again;
510 }
511 set_page_extent_mapped(page);
512
513 /*
514 * this makes sure page_mkwrite is called on the
515 * page if it is dirtied again later
516 */
517 clear_page_dirty_for_io(page);
518
519 btrfs_set_extent_delalloc(inode, page_start, page_end);
520 set_page_dirty(page);
521 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
522 unlock_page(page);
523 page_cache_release(page);
524 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
525 }
526
527 out_unlock:
528 mutex_unlock(&inode->i_mutex);
529 return 0;
530 }
531
532 static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
533 void __user *arg)
534 {
535 u64 new_size;
536 u64 old_size;
537 u64 devid = 1;
538 struct btrfs_ioctl_vol_args *vol_args;
539 struct btrfs_trans_handle *trans;
540 struct btrfs_device *device = NULL;
541 char *sizestr;
542 char *devstr = NULL;
543 int ret = 0;
544 int namelen;
545 int mod = 0;
546
547 if (root->fs_info->sb->s_flags & MS_RDONLY)
548 return -EROFS;
549
550 if (!capable(CAP_SYS_ADMIN))
551 return -EPERM;
552
553 vol_args = memdup_user(arg, sizeof(*vol_args));
554 if (IS_ERR(vol_args))
555 return PTR_ERR(vol_args);
556
557 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
558 namelen = strlen(vol_args->name);
559
560 mutex_lock(&root->fs_info->volume_mutex);
561 sizestr = vol_args->name;
562 devstr = strchr(sizestr, ':');
563 if (devstr) {
564 char *end;
565 sizestr = devstr + 1;
566 *devstr = '\0';
567 devstr = vol_args->name;
568 devid = simple_strtoull(devstr, &end, 10);
569 printk(KERN_INFO "resizing devid %llu\n",
570 (unsigned long long)devid);
571 }
572 device = btrfs_find_device(root, devid, NULL, NULL);
573 if (!device) {
574 printk(KERN_INFO "resizer unable to find device %llu\n",
575 (unsigned long long)devid);
576 ret = -EINVAL;
577 goto out_unlock;
578 }
579 if (!strcmp(sizestr, "max"))
580 new_size = device->bdev->bd_inode->i_size;
581 else {
582 if (sizestr[0] == '-') {
583 mod = -1;
584 sizestr++;
585 } else if (sizestr[0] == '+') {
586 mod = 1;
587 sizestr++;
588 }
589 new_size = btrfs_parse_size(sizestr);
590 if (new_size == 0) {
591 ret = -EINVAL;
592 goto out_unlock;
593 }
594 }
595
596 old_size = device->total_bytes;
597
598 if (mod < 0) {
599 if (new_size > old_size) {
600 ret = -EINVAL;
601 goto out_unlock;
602 }
603 new_size = old_size - new_size;
604 } else if (mod > 0) {
605 new_size = old_size + new_size;
606 }
607
608 if (new_size < 256 * 1024 * 1024) {
609 ret = -EINVAL;
610 goto out_unlock;
611 }
612 if (new_size > device->bdev->bd_inode->i_size) {
613 ret = -EFBIG;
614 goto out_unlock;
615 }
616
617 do_div(new_size, root->sectorsize);
618 new_size *= root->sectorsize;
619
620 printk(KERN_INFO "new size for %s is %llu\n",
621 device->name, (unsigned long long)new_size);
622
623 if (new_size > old_size) {
624 trans = btrfs_start_transaction(root, 1);
625 ret = btrfs_grow_device(trans, device, new_size);
626 btrfs_commit_transaction(trans, root);
627 } else {
628 ret = btrfs_shrink_device(device, new_size);
629 }
630
631 out_unlock:
632 mutex_unlock(&root->fs_info->volume_mutex);
633 kfree(vol_args);
634 return ret;
635 }
636
637 static noinline int btrfs_ioctl_snap_create(struct file *file,
638 void __user *arg, int subvol)
639 {
640 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
641 struct btrfs_ioctl_vol_args *vol_args;
642 struct file *src_file;
643 int namelen;
644 int ret = 0;
645
646 if (root->fs_info->sb->s_flags & MS_RDONLY)
647 return -EROFS;
648
649 vol_args = memdup_user(arg, sizeof(*vol_args));
650 if (IS_ERR(vol_args))
651 return PTR_ERR(vol_args);
652
653 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
654 namelen = strlen(vol_args->name);
655 if (strchr(vol_args->name, '/')) {
656 ret = -EINVAL;
657 goto out;
658 }
659
660 if (subvol) {
661 ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen,
662 NULL);
663 } else {
664 struct inode *src_inode;
665 src_file = fget(vol_args->fd);
666 if (!src_file) {
667 ret = -EINVAL;
668 goto out;
669 }
670
671 src_inode = src_file->f_path.dentry->d_inode;
672 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
673 printk(KERN_INFO "btrfs: Snapshot src from "
674 "another FS\n");
675 ret = -EINVAL;
676 fput(src_file);
677 goto out;
678 }
679 ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen,
680 BTRFS_I(src_inode)->root);
681 fput(src_file);
682 }
683 out:
684 kfree(vol_args);
685 return ret;
686 }
687
688 /*
689 * helper to check if the subvolume references other subvolumes
690 */
691 static noinline int may_destroy_subvol(struct btrfs_root *root)
692 {
693 struct btrfs_path *path;
694 struct btrfs_key key;
695 int ret;
696
697 path = btrfs_alloc_path();
698 if (!path)
699 return -ENOMEM;
700
701 key.objectid = root->root_key.objectid;
702 key.type = BTRFS_ROOT_REF_KEY;
703 key.offset = (u64)-1;
704
705 ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
706 &key, path, 0, 0);
707 if (ret < 0)
708 goto out;
709 BUG_ON(ret == 0);
710
711 ret = 0;
712 if (path->slots[0] > 0) {
713 path->slots[0]--;
714 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
715 if (key.objectid == root->root_key.objectid &&
716 key.type == BTRFS_ROOT_REF_KEY)
717 ret = -ENOTEMPTY;
718 }
719 out:
720 btrfs_free_path(path);
721 return ret;
722 }
723
724 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
725 void __user *arg)
726 {
727 struct dentry *parent = fdentry(file);
728 struct dentry *dentry;
729 struct inode *dir = parent->d_inode;
730 struct inode *inode;
731 struct btrfs_root *root = BTRFS_I(dir)->root;
732 struct btrfs_root *dest = NULL;
733 struct btrfs_ioctl_vol_args *vol_args;
734 struct btrfs_trans_handle *trans;
735 int namelen;
736 int ret;
737 int err = 0;
738
739 if (!capable(CAP_SYS_ADMIN))
740 return -EPERM;
741
742 vol_args = memdup_user(arg, sizeof(*vol_args));
743 if (IS_ERR(vol_args))
744 return PTR_ERR(vol_args);
745
746 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
747 namelen = strlen(vol_args->name);
748 if (strchr(vol_args->name, '/') ||
749 strncmp(vol_args->name, "..", namelen) == 0) {
750 err = -EINVAL;
751 goto out;
752 }
753
754 err = mnt_want_write(file->f_path.mnt);
755 if (err)
756 goto out;
757
758 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
759 dentry = lookup_one_len(vol_args->name, parent, namelen);
760 if (IS_ERR(dentry)) {
761 err = PTR_ERR(dentry);
762 goto out_unlock_dir;
763 }
764
765 if (!dentry->d_inode) {
766 err = -ENOENT;
767 goto out_dput;
768 }
769
770 inode = dentry->d_inode;
771 if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) {
772 err = -EINVAL;
773 goto out_dput;
774 }
775
776 dest = BTRFS_I(inode)->root;
777
778 mutex_lock(&inode->i_mutex);
779 err = d_invalidate(dentry);
780 if (err)
781 goto out_unlock;
782
783 down_write(&root->fs_info->subvol_sem);
784
785 err = may_destroy_subvol(dest);
786 if (err)
787 goto out_up_write;
788
789 trans = btrfs_start_transaction(root, 1);
790 ret = btrfs_unlink_subvol(trans, root, dir,
791 dest->root_key.objectid,
792 dentry->d_name.name,
793 dentry->d_name.len);
794 BUG_ON(ret);
795
796 btrfs_record_root_in_trans(trans, dest);
797
798 memset(&dest->root_item.drop_progress, 0,
799 sizeof(dest->root_item.drop_progress));
800 dest->root_item.drop_level = 0;
801 btrfs_set_root_refs(&dest->root_item, 0);
802
803 ret = btrfs_insert_orphan_item(trans,
804 root->fs_info->tree_root,
805 dest->root_key.objectid);
806 BUG_ON(ret);
807
808 ret = btrfs_commit_transaction(trans, root);
809 BUG_ON(ret);
810 inode->i_flags |= S_DEAD;
811 out_up_write:
812 up_write(&root->fs_info->subvol_sem);
813 out_unlock:
814 mutex_unlock(&inode->i_mutex);
815 if (!err) {
816 btrfs_invalidate_inodes(dest);
817 d_delete(dentry);
818 }
819 out_dput:
820 dput(dentry);
821 out_unlock_dir:
822 mutex_unlock(&dir->i_mutex);
823 mnt_drop_write(file->f_path.mnt);
824 out:
825 kfree(vol_args);
826 return err;
827 }
828
829 static int btrfs_ioctl_defrag(struct file *file)
830 {
831 struct inode *inode = fdentry(file)->d_inode;
832 struct btrfs_root *root = BTRFS_I(inode)->root;
833 int ret;
834
835 ret = mnt_want_write(file->f_path.mnt);
836 if (ret)
837 return ret;
838
839 switch (inode->i_mode & S_IFMT) {
840 case S_IFDIR:
841 if (!capable(CAP_SYS_ADMIN)) {
842 ret = -EPERM;
843 goto out;
844 }
845 btrfs_defrag_root(root, 0);
846 btrfs_defrag_root(root->fs_info->extent_root, 0);
847 break;
848 case S_IFREG:
849 if (!(file->f_mode & FMODE_WRITE)) {
850 ret = -EINVAL;
851 goto out;
852 }
853 btrfs_defrag_file(file);
854 break;
855 }
856 out:
857 mnt_drop_write(file->f_path.mnt);
858 return ret;
859 }
860
861 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
862 {
863 struct btrfs_ioctl_vol_args *vol_args;
864 int ret;
865
866 if (!capable(CAP_SYS_ADMIN))
867 return -EPERM;
868
869 vol_args = memdup_user(arg, sizeof(*vol_args));
870 if (IS_ERR(vol_args))
871 return PTR_ERR(vol_args);
872
873 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
874 ret = btrfs_init_new_device(root, vol_args->name);
875
876 kfree(vol_args);
877 return ret;
878 }
879
880 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
881 {
882 struct btrfs_ioctl_vol_args *vol_args;
883 int ret;
884
885 if (!capable(CAP_SYS_ADMIN))
886 return -EPERM;
887
888 if (root->fs_info->sb->s_flags & MS_RDONLY)
889 return -EROFS;
890
891 vol_args = memdup_user(arg, sizeof(*vol_args));
892 if (IS_ERR(vol_args))
893 return PTR_ERR(vol_args);
894
895 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
896 ret = btrfs_rm_device(root, vol_args->name);
897
898 kfree(vol_args);
899 return ret;
900 }
901
902 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
903 u64 off, u64 olen, u64 destoff)
904 {
905 struct inode *inode = fdentry(file)->d_inode;
906 struct btrfs_root *root = BTRFS_I(inode)->root;
907 struct file *src_file;
908 struct inode *src;
909 struct btrfs_trans_handle *trans;
910 struct btrfs_path *path;
911 struct extent_buffer *leaf;
912 char *buf;
913 struct btrfs_key key;
914 u32 nritems;
915 int slot;
916 int ret;
917 u64 len = olen;
918 u64 bs = root->fs_info->sb->s_blocksize;
919 u64 hint_byte;
920
921 /*
922 * TODO:
923 * - split compressed inline extents. annoying: we need to
924 * decompress into destination's address_space (the file offset
925 * may change, so source mapping won't do), then recompress (or
926 * otherwise reinsert) a subrange.
927 * - allow ranges within the same file to be cloned (provided
928 * they don't overlap)?
929 */
930
931 /* the destination must be opened for writing */
932 if (!(file->f_mode & FMODE_WRITE))
933 return -EINVAL;
934
935 ret = mnt_want_write(file->f_path.mnt);
936 if (ret)
937 return ret;
938
939 src_file = fget(srcfd);
940 if (!src_file) {
941 ret = -EBADF;
942 goto out_drop_write;
943 }
944 src = src_file->f_dentry->d_inode;
945
946 ret = -EINVAL;
947 if (src == inode)
948 goto out_fput;
949
950 ret = -EISDIR;
951 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
952 goto out_fput;
953
954 ret = -EXDEV;
955 if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
956 goto out_fput;
957
958 ret = -ENOMEM;
959 buf = vmalloc(btrfs_level_size(root, 0));
960 if (!buf)
961 goto out_fput;
962
963 path = btrfs_alloc_path();
964 if (!path) {
965 vfree(buf);
966 goto out_fput;
967 }
968 path->reada = 2;
969
970 if (inode < src) {
971 mutex_lock(&inode->i_mutex);
972 mutex_lock(&src->i_mutex);
973 } else {
974 mutex_lock(&src->i_mutex);
975 mutex_lock(&inode->i_mutex);
976 }
977
978 /* determine range to clone */
979 ret = -EINVAL;
980 if (off >= src->i_size || off + len > src->i_size)
981 goto out_unlock;
982 if (len == 0)
983 olen = len = src->i_size - off;
984 /* if we extend to eof, continue to block boundary */
985 if (off + len == src->i_size)
986 len = ((src->i_size + bs-1) & ~(bs-1))
987 - off;
988
989 /* verify the end result is block aligned */
990 if ((off & (bs-1)) ||
991 ((off + len) & (bs-1)))
992 goto out_unlock;
993
994 /* do any pending delalloc/csum calc on src, one way or
995 another, and lock file content */
996 while (1) {
997 struct btrfs_ordered_extent *ordered;
998 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
999 ordered = btrfs_lookup_first_ordered_extent(inode, off+len);
1000 if (BTRFS_I(src)->delalloc_bytes == 0 && !ordered)
1001 break;
1002 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1003 if (ordered)
1004 btrfs_put_ordered_extent(ordered);
1005 btrfs_wait_ordered_range(src, off, off+len);
1006 }
1007
1008 trans = btrfs_start_transaction(root, 1);
1009 BUG_ON(!trans);
1010
1011 /* punch hole in destination first */
1012 btrfs_drop_extents(trans, root, inode, off, off + len,
1013 off + len, 0, &hint_byte, 1);
1014
1015 /* clone data */
1016 key.objectid = src->i_ino;
1017 key.type = BTRFS_EXTENT_DATA_KEY;
1018 key.offset = 0;
1019
1020 while (1) {
1021 /*
1022 * note the key will change type as we walk through the
1023 * tree.
1024 */
1025 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
1026 if (ret < 0)
1027 goto out;
1028
1029 nritems = btrfs_header_nritems(path->nodes[0]);
1030 if (path->slots[0] >= nritems) {
1031 ret = btrfs_next_leaf(root, path);
1032 if (ret < 0)
1033 goto out;
1034 if (ret > 0)
1035 break;
1036 nritems = btrfs_header_nritems(path->nodes[0]);
1037 }
1038 leaf = path->nodes[0];
1039 slot = path->slots[0];
1040
1041 btrfs_item_key_to_cpu(leaf, &key, slot);
1042 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
1043 key.objectid != src->i_ino)
1044 break;
1045
1046 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
1047 struct btrfs_file_extent_item *extent;
1048 int type;
1049 u32 size;
1050 struct btrfs_key new_key;
1051 u64 disko = 0, diskl = 0;
1052 u64 datao = 0, datal = 0;
1053 u8 comp;
1054
1055 size = btrfs_item_size_nr(leaf, slot);
1056 read_extent_buffer(leaf, buf,
1057 btrfs_item_ptr_offset(leaf, slot),
1058 size);
1059
1060 extent = btrfs_item_ptr(leaf, slot,
1061 struct btrfs_file_extent_item);
1062 comp = btrfs_file_extent_compression(leaf, extent);
1063 type = btrfs_file_extent_type(leaf, extent);
1064 if (type == BTRFS_FILE_EXTENT_REG ||
1065 type == BTRFS_FILE_EXTENT_PREALLOC) {
1066 disko = btrfs_file_extent_disk_bytenr(leaf,
1067 extent);
1068 diskl = btrfs_file_extent_disk_num_bytes(leaf,
1069 extent);
1070 datao = btrfs_file_extent_offset(leaf, extent);
1071 datal = btrfs_file_extent_num_bytes(leaf,
1072 extent);
1073 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1074 /* take upper bound, may be compressed */
1075 datal = btrfs_file_extent_ram_bytes(leaf,
1076 extent);
1077 }
1078 btrfs_release_path(root, path);
1079
1080 if (key.offset + datal < off ||
1081 key.offset >= off+len)
1082 goto next;
1083
1084 memcpy(&new_key, &key, sizeof(new_key));
1085 new_key.objectid = inode->i_ino;
1086 new_key.offset = key.offset + destoff - off;
1087
1088 if (type == BTRFS_FILE_EXTENT_REG ||
1089 type == BTRFS_FILE_EXTENT_PREALLOC) {
1090 ret = btrfs_insert_empty_item(trans, root, path,
1091 &new_key, size);
1092 if (ret)
1093 goto out;
1094
1095 leaf = path->nodes[0];
1096 slot = path->slots[0];
1097 write_extent_buffer(leaf, buf,
1098 btrfs_item_ptr_offset(leaf, slot),
1099 size);
1100
1101 extent = btrfs_item_ptr(leaf, slot,
1102 struct btrfs_file_extent_item);
1103
1104 if (off > key.offset) {
1105 datao += off - key.offset;
1106 datal -= off - key.offset;
1107 }
1108 if (key.offset + datao + datal > off + len)
1109 datal = off + len - key.offset - datao;
1110 /* disko == 0 means it's a hole */
1111 if (!disko)
1112 datao = 0;
1113
1114 btrfs_set_file_extent_offset(leaf, extent,
1115 datao);
1116 btrfs_set_file_extent_num_bytes(leaf, extent,
1117 datal);
1118 if (disko) {
1119 inode_add_bytes(inode, datal);
1120 ret = btrfs_inc_extent_ref(trans, root,
1121 disko, diskl, 0,
1122 root->root_key.objectid,
1123 inode->i_ino,
1124 new_key.offset - datao);
1125 BUG_ON(ret);
1126 }
1127 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1128 u64 skip = 0;
1129 u64 trim = 0;
1130 if (off > key.offset) {
1131 skip = off - key.offset;
1132 new_key.offset += skip;
1133 }
1134
1135 if (key.offset + datal > off+len)
1136 trim = key.offset + datal - (off+len);
1137
1138 if (comp && (skip || trim)) {
1139 ret = -EINVAL;
1140 goto out;
1141 }
1142 size -= skip + trim;
1143 datal -= skip + trim;
1144 ret = btrfs_insert_empty_item(trans, root, path,
1145 &new_key, size);
1146 if (ret)
1147 goto out;
1148
1149 if (skip) {
1150 u32 start =
1151 btrfs_file_extent_calc_inline_size(0);
1152 memmove(buf+start, buf+start+skip,
1153 datal);
1154 }
1155
1156 leaf = path->nodes[0];
1157 slot = path->slots[0];
1158 write_extent_buffer(leaf, buf,
1159 btrfs_item_ptr_offset(leaf, slot),
1160 size);
1161 inode_add_bytes(inode, datal);
1162 }
1163
1164 btrfs_mark_buffer_dirty(leaf);
1165 }
1166
1167 next:
1168 btrfs_release_path(root, path);
1169 key.offset++;
1170 }
1171 ret = 0;
1172 out:
1173 btrfs_release_path(root, path);
1174 if (ret == 0) {
1175 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1176 if (destoff + olen > inode->i_size)
1177 btrfs_i_size_write(inode, destoff + olen);
1178 BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
1179 ret = btrfs_update_inode(trans, root, inode);
1180 }
1181 btrfs_end_transaction(trans, root);
1182 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1183 if (ret)
1184 vmtruncate(inode, 0);
1185 out_unlock:
1186 mutex_unlock(&src->i_mutex);
1187 mutex_unlock(&inode->i_mutex);
1188 vfree(buf);
1189 btrfs_free_path(path);
1190 out_fput:
1191 fput(src_file);
1192 out_drop_write:
1193 mnt_drop_write(file->f_path.mnt);
1194 return ret;
1195 }
1196
1197 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
1198 {
1199 struct btrfs_ioctl_clone_range_args args;
1200
1201 if (copy_from_user(&args, argp, sizeof(args)))
1202 return -EFAULT;
1203 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
1204 args.src_length, args.dest_offset);
1205 }
1206
1207 /*
1208 * there are many ways the trans_start and trans_end ioctls can lead
1209 * to deadlocks. They should only be used by applications that
1210 * basically own the machine, and have a very in depth understanding
1211 * of all the possible deadlocks and enospc problems.
1212 */
1213 static long btrfs_ioctl_trans_start(struct file *file)
1214 {
1215 struct inode *inode = fdentry(file)->d_inode;
1216 struct btrfs_root *root = BTRFS_I(inode)->root;
1217 struct btrfs_trans_handle *trans;
1218 int ret = 0;
1219
1220 if (!capable(CAP_SYS_ADMIN))
1221 return -EPERM;
1222
1223 if (file->private_data) {
1224 ret = -EINPROGRESS;
1225 goto out;
1226 }
1227
1228 ret = mnt_want_write(file->f_path.mnt);
1229 if (ret)
1230 goto out;
1231
1232 mutex_lock(&root->fs_info->trans_mutex);
1233 root->fs_info->open_ioctl_trans++;
1234 mutex_unlock(&root->fs_info->trans_mutex);
1235
1236 trans = btrfs_start_ioctl_transaction(root, 0);
1237 if (trans)
1238 file->private_data = trans;
1239 else
1240 ret = -ENOMEM;
1241 /*printk(KERN_INFO "btrfs_ioctl_trans_start on %p\n", file);*/
1242 out:
1243 return ret;
1244 }
1245
1246 /*
1247 * there are many ways the trans_start and trans_end ioctls can lead
1248 * to deadlocks. They should only be used by applications that
1249 * basically own the machine, and have a very in depth understanding
1250 * of all the possible deadlocks and enospc problems.
1251 */
1252 long btrfs_ioctl_trans_end(struct file *file)
1253 {
1254 struct inode *inode = fdentry(file)->d_inode;
1255 struct btrfs_root *root = BTRFS_I(inode)->root;
1256 struct btrfs_trans_handle *trans;
1257 int ret = 0;
1258
1259 trans = file->private_data;
1260 if (!trans) {
1261 ret = -EINVAL;
1262 goto out;
1263 }
1264 btrfs_end_transaction(trans, root);
1265 file->private_data = NULL;
1266
1267 mutex_lock(&root->fs_info->trans_mutex);
1268 root->fs_info->open_ioctl_trans--;
1269 mutex_unlock(&root->fs_info->trans_mutex);
1270
1271 mnt_drop_write(file->f_path.mnt);
1272
1273 out:
1274 return ret;
1275 }
1276
1277 long btrfs_ioctl(struct file *file, unsigned int
1278 cmd, unsigned long arg)
1279 {
1280 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
1281 void __user *argp = (void __user *)arg;
1282
1283 switch (cmd) {
1284 case FS_IOC_GETFLAGS:
1285 return btrfs_ioctl_getflags(file, argp);
1286 case FS_IOC_SETFLAGS:
1287 return btrfs_ioctl_setflags(file, argp);
1288 case FS_IOC_GETVERSION:
1289 return btrfs_ioctl_getversion(file, argp);
1290 case BTRFS_IOC_SNAP_CREATE:
1291 return btrfs_ioctl_snap_create(file, argp, 0);
1292 case BTRFS_IOC_SUBVOL_CREATE:
1293 return btrfs_ioctl_snap_create(file, argp, 1);
1294 case BTRFS_IOC_SNAP_DESTROY:
1295 return btrfs_ioctl_snap_destroy(file, argp);
1296 case BTRFS_IOC_DEFRAG:
1297 return btrfs_ioctl_defrag(file);
1298 case BTRFS_IOC_RESIZE:
1299 return btrfs_ioctl_resize(root, argp);
1300 case BTRFS_IOC_ADD_DEV:
1301 return btrfs_ioctl_add_dev(root, argp);
1302 case BTRFS_IOC_RM_DEV:
1303 return btrfs_ioctl_rm_dev(root, argp);
1304 case BTRFS_IOC_BALANCE:
1305 return btrfs_balance(root->fs_info->dev_root);
1306 case BTRFS_IOC_CLONE:
1307 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
1308 case BTRFS_IOC_CLONE_RANGE:
1309 return btrfs_ioctl_clone_range(file, argp);
1310 case BTRFS_IOC_TRANS_START:
1311 return btrfs_ioctl_trans_start(file);
1312 case BTRFS_IOC_TRANS_END:
1313 return btrfs_ioctl_trans_end(file);
1314 case BTRFS_IOC_SYNC:
1315 btrfs_sync_fs(file->f_dentry->d_sb, 1);
1316 return 0;
1317 }
1318
1319 return -ENOTTY;
1320 }
Linux kernel - Deliverables
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