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x86/amd-iommu: Add per IOMMU reference counting
[linux/fpc-iii.git] / fs / btrfs / ioctl.c
blobcdbb054102b9f860ee4d119dfff39e891ac29438
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 /*
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, 0);
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 nr = trans->blocks_used;
346 err = btrfs_commit_transaction(trans, root);
347 if (err && !ret)
348 ret = err;
349
350 btrfs_unreserve_metadata_space(root, 6);
351 btrfs_btree_balance_dirty(root, nr);
352 return ret;
353 }
354
355 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
356 char *name, int namelen)
357 {
358 struct btrfs_pending_snapshot *pending_snapshot;
359 struct btrfs_trans_handle *trans;
360 int ret = 0;
361 int err;
362 unsigned long nr = 0;
363
364 if (!root->ref_cows)
365 return -EINVAL;
366
367 /*
368 * 1 - inode item
369 * 2 - refs
370 * 1 - root item
371 * 2 - dir items
372 */
373 ret = btrfs_reserve_metadata_space(root, 6);
374 if (ret)
375 goto fail_unlock;
376
377 pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
378 if (!pending_snapshot) {
379 ret = -ENOMEM;
380 btrfs_unreserve_metadata_space(root, 6);
381 goto fail_unlock;
382 }
383 pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
384 if (!pending_snapshot->name) {
385 ret = -ENOMEM;
386 kfree(pending_snapshot);
387 btrfs_unreserve_metadata_space(root, 6);
388 goto fail_unlock;
389 }
390 memcpy(pending_snapshot->name, name, namelen);
391 pending_snapshot->name[namelen] = '\0';
392 pending_snapshot->dentry = dentry;
393 trans = btrfs_start_transaction(root, 1);
394 BUG_ON(!trans);
395 pending_snapshot->root = root;
396 list_add(&pending_snapshot->list,
397 &trans->transaction->pending_snapshots);
398 err = btrfs_commit_transaction(trans, root);
399
400 fail_unlock:
401 btrfs_btree_balance_dirty(root, nr);
402 return ret;
403 }
404
405 /* copy of may_create in fs/namei.c() */
406 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
407 {
408 if (child->d_inode)
409 return -EEXIST;
410 if (IS_DEADDIR(dir))
411 return -ENOENT;
412 return inode_permission(dir, MAY_WRITE | MAY_EXEC);
413 }
414
415 /*
416 * Create a new subvolume below @parent. This is largely modeled after
417 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
418 * inside this filesystem so it's quite a bit simpler.
419 */
420 static noinline int btrfs_mksubvol(struct path *parent,
421 char *name, int namelen,
422 struct btrfs_root *snap_src)
423 {
424 struct inode *dir = parent->dentry->d_inode;
425 struct dentry *dentry;
426 int error;
427
428 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
429
430 dentry = lookup_one_len(name, parent->dentry, namelen);
431 error = PTR_ERR(dentry);
432 if (IS_ERR(dentry))
433 goto out_unlock;
434
435 error = -EEXIST;
436 if (dentry->d_inode)
437 goto out_dput;
438
439 error = mnt_want_write(parent->mnt);
440 if (error)
441 goto out_dput;
442
443 error = btrfs_may_create(dir, dentry);
444 if (error)
445 goto out_drop_write;
446
447 down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
448
449 if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
450 goto out_up_read;
451
452 if (snap_src) {
453 error = create_snapshot(snap_src, dentry,
454 name, namelen);
455 } else {
456 error = create_subvol(BTRFS_I(dir)->root, dentry,
457 name, namelen);
458 }
459 if (!error)
460 fsnotify_mkdir(dir, dentry);
461 out_up_read:
462 up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
463 out_drop_write:
464 mnt_drop_write(parent->mnt);
465 out_dput:
466 dput(dentry);
467 out_unlock:
468 mutex_unlock(&dir->i_mutex);
469 return error;
470 }
471
472 static int btrfs_defrag_file(struct file *file)
473 {
474 struct inode *inode = fdentry(file)->d_inode;
475 struct btrfs_root *root = BTRFS_I(inode)->root;
476 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
477 struct btrfs_ordered_extent *ordered;
478 struct page *page;
479 unsigned long last_index;
480 unsigned long ra_pages = root->fs_info->bdi.ra_pages;
481 unsigned long total_read = 0;
482 u64 page_start;
483 u64 page_end;
484 unsigned long i;
485 int ret;
486
487 ret = btrfs_check_data_free_space(root, inode, inode->i_size);
488 if (ret)
489 return -ENOSPC;
490
491 mutex_lock(&inode->i_mutex);
492 last_index = inode->i_size >> PAGE_CACHE_SHIFT;
493 for (i = 0; i <= last_index; i++) {
494 if (total_read % ra_pages == 0) {
495 btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
496 min(last_index, i + ra_pages - 1));
497 }
498 total_read++;
499 again:
500 page = grab_cache_page(inode->i_mapping, i);
501 if (!page)
502 goto out_unlock;
503 if (!PageUptodate(page)) {
504 btrfs_readpage(NULL, page);
505 lock_page(page);
506 if (!PageUptodate(page)) {
507 unlock_page(page);
508 page_cache_release(page);
509 goto out_unlock;
510 }
511 }
512
513 wait_on_page_writeback(page);
514
515 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
516 page_end = page_start + PAGE_CACHE_SIZE - 1;
517 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
518
519 ordered = btrfs_lookup_ordered_extent(inode, page_start);
520 if (ordered) {
521 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
522 unlock_page(page);
523 page_cache_release(page);
524 btrfs_start_ordered_extent(inode, ordered, 1);
525 btrfs_put_ordered_extent(ordered);
526 goto again;
527 }
528 set_page_extent_mapped(page);
529
530 /*
531 * this makes sure page_mkwrite is called on the
532 * page if it is dirtied again later
533 */
534 clear_page_dirty_for_io(page);
535
536 btrfs_set_extent_delalloc(inode, page_start, page_end);
537 set_page_dirty(page);
538 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
539 unlock_page(page);
540 page_cache_release(page);
541 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
542 }
543
544 out_unlock:
545 mutex_unlock(&inode->i_mutex);
546 return 0;
547 }
548
549 static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
550 void __user *arg)
551 {
552 u64 new_size;
553 u64 old_size;
554 u64 devid = 1;
555 struct btrfs_ioctl_vol_args *vol_args;
556 struct btrfs_trans_handle *trans;
557 struct btrfs_device *device = NULL;
558 char *sizestr;
559 char *devstr = NULL;
560 int ret = 0;
561 int namelen;
562 int mod = 0;
563
564 if (root->fs_info->sb->s_flags & MS_RDONLY)
565 return -EROFS;
566
567 if (!capable(CAP_SYS_ADMIN))
568 return -EPERM;
569
570 vol_args = memdup_user(arg, sizeof(*vol_args));
571 if (IS_ERR(vol_args))
572 return PTR_ERR(vol_args);
573
574 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
575 namelen = strlen(vol_args->name);
576
577 mutex_lock(&root->fs_info->volume_mutex);
578 sizestr = vol_args->name;
579 devstr = strchr(sizestr, ':');
580 if (devstr) {
581 char *end;
582 sizestr = devstr + 1;
583 *devstr = '\0';
584 devstr = vol_args->name;
585 devid = simple_strtoull(devstr, &end, 10);
586 printk(KERN_INFO "resizing devid %llu\n",
587 (unsigned long long)devid);
588 }
589 device = btrfs_find_device(root, devid, NULL, NULL);
590 if (!device) {
591 printk(KERN_INFO "resizer unable to find device %llu\n",
592 (unsigned long long)devid);
593 ret = -EINVAL;
594 goto out_unlock;
595 }
596 if (!strcmp(sizestr, "max"))
597 new_size = device->bdev->bd_inode->i_size;
598 else {
599 if (sizestr[0] == '-') {
600 mod = -1;
601 sizestr++;
602 } else if (sizestr[0] == '+') {
603 mod = 1;
604 sizestr++;
605 }
606 new_size = btrfs_parse_size(sizestr);
607 if (new_size == 0) {
608 ret = -EINVAL;
609 goto out_unlock;
610 }
611 }
612
613 old_size = device->total_bytes;
614
615 if (mod < 0) {
616 if (new_size > old_size) {
617 ret = -EINVAL;
618 goto out_unlock;
619 }
620 new_size = old_size - new_size;
621 } else if (mod > 0) {
622 new_size = old_size + new_size;
623 }
624
625 if (new_size < 256 * 1024 * 1024) {
626 ret = -EINVAL;
627 goto out_unlock;
628 }
629 if (new_size > device->bdev->bd_inode->i_size) {
630 ret = -EFBIG;
631 goto out_unlock;
632 }
633
634 do_div(new_size, root->sectorsize);
635 new_size *= root->sectorsize;
636
637 printk(KERN_INFO "new size for %s is %llu\n",
638 device->name, (unsigned long long)new_size);
639
640 if (new_size > old_size) {
641 trans = btrfs_start_transaction(root, 1);
642 ret = btrfs_grow_device(trans, device, new_size);
643 btrfs_commit_transaction(trans, root);
644 } else {
645 ret = btrfs_shrink_device(device, new_size);
646 }
647
648 out_unlock:
649 mutex_unlock(&root->fs_info->volume_mutex);
650 kfree(vol_args);
651 return ret;
652 }
653
654 static noinline int btrfs_ioctl_snap_create(struct file *file,
655 void __user *arg, int subvol)
656 {
657 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
658 struct btrfs_ioctl_vol_args *vol_args;
659 struct file *src_file;
660 int namelen;
661 int ret = 0;
662
663 if (root->fs_info->sb->s_flags & MS_RDONLY)
664 return -EROFS;
665
666 vol_args = memdup_user(arg, sizeof(*vol_args));
667 if (IS_ERR(vol_args))
668 return PTR_ERR(vol_args);
669
670 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
671 namelen = strlen(vol_args->name);
672 if (strchr(vol_args->name, '/')) {
673 ret = -EINVAL;
674 goto out;
675 }
676
677 if (subvol) {
678 ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen,
679 NULL);
680 } else {
681 struct inode *src_inode;
682 src_file = fget(vol_args->fd);
683 if (!src_file) {
684 ret = -EINVAL;
685 goto out;
686 }
687
688 src_inode = src_file->f_path.dentry->d_inode;
689 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
690 printk(KERN_INFO "btrfs: Snapshot src from "
691 "another FS\n");
692 ret = -EINVAL;
693 fput(src_file);
694 goto out;
695 }
696 ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen,
697 BTRFS_I(src_inode)->root);
698 fput(src_file);
699 }
700 out:
701 kfree(vol_args);
702 return ret;
703 }
704
705 /*
706 * helper to check if the subvolume references other subvolumes
707 */
708 static noinline int may_destroy_subvol(struct btrfs_root *root)
709 {
710 struct btrfs_path *path;
711 struct btrfs_key key;
712 int ret;
713
714 path = btrfs_alloc_path();
715 if (!path)
716 return -ENOMEM;
717
718 key.objectid = root->root_key.objectid;
719 key.type = BTRFS_ROOT_REF_KEY;
720 key.offset = (u64)-1;
721
722 ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
723 &key, path, 0, 0);
724 if (ret < 0)
725 goto out;
726 BUG_ON(ret == 0);
727
728 ret = 0;
729 if (path->slots[0] > 0) {
730 path->slots[0]--;
731 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
732 if (key.objectid == root->root_key.objectid &&
733 key.type == BTRFS_ROOT_REF_KEY)
734 ret = -ENOTEMPTY;
735 }
736 out:
737 btrfs_free_path(path);
738 return ret;
739 }
740
741 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
742 void __user *arg)
743 {
744 struct dentry *parent = fdentry(file);
745 struct dentry *dentry;
746 struct inode *dir = parent->d_inode;
747 struct inode *inode;
748 struct btrfs_root *root = BTRFS_I(dir)->root;
749 struct btrfs_root *dest = NULL;
750 struct btrfs_ioctl_vol_args *vol_args;
751 struct btrfs_trans_handle *trans;
752 int namelen;
753 int ret;
754 int err = 0;
755
756 if (!capable(CAP_SYS_ADMIN))
757 return -EPERM;
758
759 vol_args = memdup_user(arg, sizeof(*vol_args));
760 if (IS_ERR(vol_args))
761 return PTR_ERR(vol_args);
762
763 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
764 namelen = strlen(vol_args->name);
765 if (strchr(vol_args->name, '/') ||
766 strncmp(vol_args->name, "..", namelen) == 0) {
767 err = -EINVAL;
768 goto out;
769 }
770
771 err = mnt_want_write(file->f_path.mnt);
772 if (err)
773 goto out;
774
775 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
776 dentry = lookup_one_len(vol_args->name, parent, namelen);
777 if (IS_ERR(dentry)) {
778 err = PTR_ERR(dentry);
779 goto out_unlock_dir;
780 }
781
782 if (!dentry->d_inode) {
783 err = -ENOENT;
784 goto out_dput;
785 }
786
787 inode = dentry->d_inode;
788 if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) {
789 err = -EINVAL;
790 goto out_dput;
791 }
792
793 dest = BTRFS_I(inode)->root;
794
795 mutex_lock(&inode->i_mutex);
796 err = d_invalidate(dentry);
797 if (err)
798 goto out_unlock;
799
800 down_write(&root->fs_info->subvol_sem);
801
802 err = may_destroy_subvol(dest);
803 if (err)
804 goto out_up_write;
805
806 trans = btrfs_start_transaction(root, 1);
807 ret = btrfs_unlink_subvol(trans, root, dir,
808 dest->root_key.objectid,
809 dentry->d_name.name,
810 dentry->d_name.len);
811 BUG_ON(ret);
812
813 btrfs_record_root_in_trans(trans, dest);
814
815 memset(&dest->root_item.drop_progress, 0,
816 sizeof(dest->root_item.drop_progress));
817 dest->root_item.drop_level = 0;
818 btrfs_set_root_refs(&dest->root_item, 0);
819
820 ret = btrfs_insert_orphan_item(trans,
821 root->fs_info->tree_root,
822 dest->root_key.objectid);
823 BUG_ON(ret);
824
825 ret = btrfs_commit_transaction(trans, root);
826 BUG_ON(ret);
827 inode->i_flags |= S_DEAD;
828 out_up_write:
829 up_write(&root->fs_info->subvol_sem);
830 out_unlock:
831 mutex_unlock(&inode->i_mutex);
832 if (!err) {
833 shrink_dcache_sb(root->fs_info->sb);
834 btrfs_invalidate_inodes(dest);
835 d_delete(dentry);
836 }
837 out_dput:
838 dput(dentry);
839 out_unlock_dir:
840 mutex_unlock(&dir->i_mutex);
841 mnt_drop_write(file->f_path.mnt);
842 out:
843 kfree(vol_args);
844 return err;
845 }
846
847 static int btrfs_ioctl_defrag(struct file *file)
848 {
849 struct inode *inode = fdentry(file)->d_inode;
850 struct btrfs_root *root = BTRFS_I(inode)->root;
851 int ret;
852
853 ret = mnt_want_write(file->f_path.mnt);
854 if (ret)
855 return ret;
856
857 switch (inode->i_mode & S_IFMT) {
858 case S_IFDIR:
859 if (!capable(CAP_SYS_ADMIN)) {
860 ret = -EPERM;
861 goto out;
862 }
863 btrfs_defrag_root(root, 0);
864 btrfs_defrag_root(root->fs_info->extent_root, 0);
865 break;
866 case S_IFREG:
867 if (!(file->f_mode & FMODE_WRITE)) {
868 ret = -EINVAL;
869 goto out;
870 }
871 btrfs_defrag_file(file);
872 break;
873 }
874 out:
875 mnt_drop_write(file->f_path.mnt);
876 return ret;
877 }
878
879 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
880 {
881 struct btrfs_ioctl_vol_args *vol_args;
882 int ret;
883
884 if (!capable(CAP_SYS_ADMIN))
885 return -EPERM;
886
887 vol_args = memdup_user(arg, sizeof(*vol_args));
888 if (IS_ERR(vol_args))
889 return PTR_ERR(vol_args);
890
891 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
892 ret = btrfs_init_new_device(root, vol_args->name);
893
894 kfree(vol_args);
895 return ret;
896 }
897
898 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
899 {
900 struct btrfs_ioctl_vol_args *vol_args;
901 int ret;
902
903 if (!capable(CAP_SYS_ADMIN))
904 return -EPERM;
905
906 if (root->fs_info->sb->s_flags & MS_RDONLY)
907 return -EROFS;
908
909 vol_args = memdup_user(arg, sizeof(*vol_args));
910 if (IS_ERR(vol_args))
911 return PTR_ERR(vol_args);
912
913 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
914 ret = btrfs_rm_device(root, vol_args->name);
915
916 kfree(vol_args);
917 return ret;
918 }
919
920 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
921 u64 off, u64 olen, u64 destoff)
922 {
923 struct inode *inode = fdentry(file)->d_inode;
924 struct btrfs_root *root = BTRFS_I(inode)->root;
925 struct file *src_file;
926 struct inode *src;
927 struct btrfs_trans_handle *trans;
928 struct btrfs_path *path;
929 struct extent_buffer *leaf;
930 char *buf;
931 struct btrfs_key key;
932 u32 nritems;
933 int slot;
934 int ret;
935 u64 len = olen;
936 u64 bs = root->fs_info->sb->s_blocksize;
937 u64 hint_byte;
938
939 /*
940 * TODO:
941 * - split compressed inline extents. annoying: we need to
942 * decompress into destination's address_space (the file offset
943 * may change, so source mapping won't do), then recompress (or
944 * otherwise reinsert) a subrange.
945 * - allow ranges within the same file to be cloned (provided
946 * they don't overlap)?
947 */
948
949 /* the destination must be opened for writing */
950 if (!(file->f_mode & FMODE_WRITE))
951 return -EINVAL;
952
953 ret = mnt_want_write(file->f_path.mnt);
954 if (ret)
955 return ret;
956
957 src_file = fget(srcfd);
958 if (!src_file) {
959 ret = -EBADF;
960 goto out_drop_write;
961 }
962 src = src_file->f_dentry->d_inode;
963
964 ret = -EINVAL;
965 if (src == inode)
966 goto out_fput;
967
968 ret = -EISDIR;
969 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
970 goto out_fput;
971
972 ret = -EXDEV;
973 if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
974 goto out_fput;
975
976 ret = -ENOMEM;
977 buf = vmalloc(btrfs_level_size(root, 0));
978 if (!buf)
979 goto out_fput;
980
981 path = btrfs_alloc_path();
982 if (!path) {
983 vfree(buf);
984 goto out_fput;
985 }
986 path->reada = 2;
987
988 if (inode < src) {
989 mutex_lock(&inode->i_mutex);
990 mutex_lock(&src->i_mutex);
991 } else {
992 mutex_lock(&src->i_mutex);
993 mutex_lock(&inode->i_mutex);
994 }
995
996 /* determine range to clone */
997 ret = -EINVAL;
998 if (off >= src->i_size || off + len > src->i_size)
999 goto out_unlock;
1000 if (len == 0)
1001 olen = len = src->i_size - off;
1002 /* if we extend to eof, continue to block boundary */
1003 if (off + len == src->i_size)
1004 len = ((src->i_size + bs-1) & ~(bs-1))
1005 - off;
1006
1007 /* verify the end result is block aligned */
1008 if ((off & (bs-1)) ||
1009 ((off + len) & (bs-1)))
1010 goto out_unlock;
1011
1012 /* do any pending delalloc/csum calc on src, one way or
1013 another, and lock file content */
1014 while (1) {
1015 struct btrfs_ordered_extent *ordered;
1016 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1017 ordered = btrfs_lookup_first_ordered_extent(inode, off+len);
1018 if (BTRFS_I(src)->delalloc_bytes == 0 && !ordered)
1019 break;
1020 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1021 if (ordered)
1022 btrfs_put_ordered_extent(ordered);
1023 btrfs_wait_ordered_range(src, off, off+len);
1024 }
1025
1026 trans = btrfs_start_transaction(root, 1);
1027 BUG_ON(!trans);
1028
1029 /* punch hole in destination first */
1030 btrfs_drop_extents(trans, root, inode, off, off + len,
1031 off + len, 0, &hint_byte, 1);
1032
1033 /* clone data */
1034 key.objectid = src->i_ino;
1035 key.type = BTRFS_EXTENT_DATA_KEY;
1036 key.offset = 0;
1037
1038 while (1) {
1039 /*
1040 * note the key will change type as we walk through the
1041 * tree.
1042 */
1043 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
1044 if (ret < 0)
1045 goto out;
1046
1047 nritems = btrfs_header_nritems(path->nodes[0]);
1048 if (path->slots[0] >= nritems) {
1049 ret = btrfs_next_leaf(root, path);
1050 if (ret < 0)
1051 goto out;
1052 if (ret > 0)
1053 break;
1054 nritems = btrfs_header_nritems(path->nodes[0]);
1055 }
1056 leaf = path->nodes[0];
1057 slot = path->slots[0];
1058
1059 btrfs_item_key_to_cpu(leaf, &key, slot);
1060 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
1061 key.objectid != src->i_ino)
1062 break;
1063
1064 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
1065 struct btrfs_file_extent_item *extent;
1066 int type;
1067 u32 size;
1068 struct btrfs_key new_key;
1069 u64 disko = 0, diskl = 0;
1070 u64 datao = 0, datal = 0;
1071 u8 comp;
1072
1073 size = btrfs_item_size_nr(leaf, slot);
1074 read_extent_buffer(leaf, buf,
1075 btrfs_item_ptr_offset(leaf, slot),
1076 size);
1077
1078 extent = btrfs_item_ptr(leaf, slot,
1079 struct btrfs_file_extent_item);
1080 comp = btrfs_file_extent_compression(leaf, extent);
1081 type = btrfs_file_extent_type(leaf, extent);
1082 if (type == BTRFS_FILE_EXTENT_REG ||
1083 type == BTRFS_FILE_EXTENT_PREALLOC) {
1084 disko = btrfs_file_extent_disk_bytenr(leaf,
1085 extent);
1086 diskl = btrfs_file_extent_disk_num_bytes(leaf,
1087 extent);
1088 datao = btrfs_file_extent_offset(leaf, extent);
1089 datal = btrfs_file_extent_num_bytes(leaf,
1090 extent);
1091 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1092 /* take upper bound, may be compressed */
1093 datal = btrfs_file_extent_ram_bytes(leaf,
1094 extent);
1095 }
1096 btrfs_release_path(root, path);
1097
1098 if (key.offset + datal < off ||
1099 key.offset >= off+len)
1100 goto next;
1101
1102 memcpy(&new_key, &key, sizeof(new_key));
1103 new_key.objectid = inode->i_ino;
1104 new_key.offset = key.offset + destoff - off;
1105
1106 if (type == BTRFS_FILE_EXTENT_REG ||
1107 type == BTRFS_FILE_EXTENT_PREALLOC) {
1108 ret = btrfs_insert_empty_item(trans, root, path,
1109 &new_key, size);
1110 if (ret)
1111 goto out;
1112
1113 leaf = path->nodes[0];
1114 slot = path->slots[0];
1115 write_extent_buffer(leaf, buf,
1116 btrfs_item_ptr_offset(leaf, slot),
1117 size);
1118
1119 extent = btrfs_item_ptr(leaf, slot,
1120 struct btrfs_file_extent_item);
1121
1122 if (off > key.offset) {
1123 datao += off - key.offset;
1124 datal -= off - key.offset;
1125 }
1126
1127 if (key.offset + datal > off + len)
1128 datal = off + len - key.offset;
1129
1130 /* disko == 0 means it's a hole */
1131 if (!disko)
1132 datao = 0;
1133
1134 btrfs_set_file_extent_offset(leaf, extent,
1135 datao);
1136 btrfs_set_file_extent_num_bytes(leaf, extent,
1137 datal);
1138 if (disko) {
1139 inode_add_bytes(inode, datal);
1140 ret = btrfs_inc_extent_ref(trans, root,
1141 disko, diskl, 0,
1142 root->root_key.objectid,
1143 inode->i_ino,
1144 new_key.offset - datao);
1145 BUG_ON(ret);
1146 }
1147 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1148 u64 skip = 0;
1149 u64 trim = 0;
1150 if (off > key.offset) {
1151 skip = off - key.offset;
1152 new_key.offset += skip;
1153 }
1154
1155 if (key.offset + datal > off+len)
1156 trim = key.offset + datal - (off+len);
1157
1158 if (comp && (skip || trim)) {
1159 ret = -EINVAL;
1160 goto out;
1161 }
1162 size -= skip + trim;
1163 datal -= skip + trim;
1164 ret = btrfs_insert_empty_item(trans, root, path,
1165 &new_key, size);
1166 if (ret)
1167 goto out;
1168
1169 if (skip) {
1170 u32 start =
1171 btrfs_file_extent_calc_inline_size(0);
1172 memmove(buf+start, buf+start+skip,
1173 datal);
1174 }
1175
1176 leaf = path->nodes[0];
1177 slot = path->slots[0];
1178 write_extent_buffer(leaf, buf,
1179 btrfs_item_ptr_offset(leaf, slot),
1180 size);
1181 inode_add_bytes(inode, datal);
1182 }
1183
1184 btrfs_mark_buffer_dirty(leaf);
1185 }
1186
1187 next:
1188 btrfs_release_path(root, path);
1189 key.offset++;
1190 }
1191 ret = 0;
1192 out:
1193 btrfs_release_path(root, path);
1194 if (ret == 0) {
1195 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1196 if (destoff + olen > inode->i_size)
1197 btrfs_i_size_write(inode, destoff + olen);
1198 BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
1199 ret = btrfs_update_inode(trans, root, inode);
1200 }
1201 btrfs_end_transaction(trans, root);
1202 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1203 if (ret)
1204 vmtruncate(inode, 0);
1205 out_unlock:
1206 mutex_unlock(&src->i_mutex);
1207 mutex_unlock(&inode->i_mutex);
1208 vfree(buf);
1209 btrfs_free_path(path);
1210 out_fput:
1211 fput(src_file);
1212 out_drop_write:
1213 mnt_drop_write(file->f_path.mnt);
1214 return ret;
1215 }
1216
1217 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
1218 {
1219 struct btrfs_ioctl_clone_range_args args;
1220
1221 if (copy_from_user(&args, argp, sizeof(args)))
1222 return -EFAULT;
1223 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
1224 args.src_length, args.dest_offset);
1225 }
1226
1227 /*
1228 * there are many ways the trans_start and trans_end ioctls can lead
1229 * to deadlocks. They should only be used by applications that
1230 * basically own the machine, and have a very in depth understanding
1231 * of all the possible deadlocks and enospc problems.
1232 */
1233 static long btrfs_ioctl_trans_start(struct file *file)
1234 {
1235 struct inode *inode = fdentry(file)->d_inode;
1236 struct btrfs_root *root = BTRFS_I(inode)->root;
1237 struct btrfs_trans_handle *trans;
1238 int ret;
1239
1240 ret = -EPERM;
1241 if (!capable(CAP_SYS_ADMIN))
1242 goto out;
1243
1244 ret = -EINPROGRESS;
1245 if (file->private_data)
1246 goto out;
1247
1248 ret = mnt_want_write(file->f_path.mnt);
1249 if (ret)
1250 goto out;
1251
1252 mutex_lock(&root->fs_info->trans_mutex);
1253 root->fs_info->open_ioctl_trans++;
1254 mutex_unlock(&root->fs_info->trans_mutex);
1255
1256 ret = -ENOMEM;
1257 trans = btrfs_start_ioctl_transaction(root, 0);
1258 if (!trans)
1259 goto out_drop;
1260
1261 file->private_data = trans;
1262 return 0;
1263
1264 out_drop:
1265 mutex_lock(&root->fs_info->trans_mutex);
1266 root->fs_info->open_ioctl_trans--;
1267 mutex_unlock(&root->fs_info->trans_mutex);
1268 mnt_drop_write(file->f_path.mnt);
1269 out:
1270 return ret;
1271 }
1272
1273 /*
1274 * there are many ways the trans_start and trans_end ioctls can lead
1275 * to deadlocks. They should only be used by applications that
1276 * basically own the machine, and have a very in depth understanding
1277 * of all the possible deadlocks and enospc problems.
1278 */
1279 long btrfs_ioctl_trans_end(struct file *file)
1280 {
1281 struct inode *inode = fdentry(file)->d_inode;
1282 struct btrfs_root *root = BTRFS_I(inode)->root;
1283 struct btrfs_trans_handle *trans;
1284
1285 trans = file->private_data;
1286 if (!trans)
1287 return -EINVAL;
1288 file->private_data = NULL;
1289
1290 btrfs_end_transaction(trans, root);
1291
1292 mutex_lock(&root->fs_info->trans_mutex);
1293 root->fs_info->open_ioctl_trans--;
1294 mutex_unlock(&root->fs_info->trans_mutex);
1295
1296 mnt_drop_write(file->f_path.mnt);
1297 return 0;
1298 }
1299
1300 long btrfs_ioctl(struct file *file, unsigned int
1301 cmd, unsigned long arg)
1302 {
1303 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
1304 void __user *argp = (void __user *)arg;
1305
1306 switch (cmd) {
1307 case FS_IOC_GETFLAGS:
1308 return btrfs_ioctl_getflags(file, argp);
1309 case FS_IOC_SETFLAGS:
1310 return btrfs_ioctl_setflags(file, argp);
1311 case FS_IOC_GETVERSION:
1312 return btrfs_ioctl_getversion(file, argp);
1313 case BTRFS_IOC_SNAP_CREATE:
1314 return btrfs_ioctl_snap_create(file, argp, 0);
1315 case BTRFS_IOC_SUBVOL_CREATE:
1316 return btrfs_ioctl_snap_create(file, argp, 1);
1317 case BTRFS_IOC_SNAP_DESTROY:
1318 return btrfs_ioctl_snap_destroy(file, argp);
1319 case BTRFS_IOC_DEFRAG:
1320 return btrfs_ioctl_defrag(file);
1321 case BTRFS_IOC_RESIZE:
1322 return btrfs_ioctl_resize(root, argp);
1323 case BTRFS_IOC_ADD_DEV:
1324 return btrfs_ioctl_add_dev(root, argp);
1325 case BTRFS_IOC_RM_DEV:
1326 return btrfs_ioctl_rm_dev(root, argp);
1327 case BTRFS_IOC_BALANCE:
1328 return btrfs_balance(root->fs_info->dev_root);
1329 case BTRFS_IOC_CLONE:
1330 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
1331 case BTRFS_IOC_CLONE_RANGE:
1332 return btrfs_ioctl_clone_range(file, argp);
1333 case BTRFS_IOC_TRANS_START:
1334 return btrfs_ioctl_trans_start(file);
1335 case BTRFS_IOC_TRANS_END:
1336 return btrfs_ioctl_trans_end(file);
1337 case BTRFS_IOC_SYNC:
1338 btrfs_sync_fs(file->f_dentry->d_sb, 1);
1339 return 0;
1340 }
1341
1342 return -ENOTTY;
1343 }
Linux with added FPC-III support