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Btrfs: btrfs: pass void __user * to btrfs_ioctl_clone_range
[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/smp_lock.h>
31 #include <linux/backing-dev.h>
32 #include <linux/mount.h>
33 #include <linux/mpage.h>
34 #include <linux/namei.h>
35 #include <linux/swap.h>
36 #include <linux/writeback.h>
37 #include <linux/statfs.h>
38 #include <linux/compat.h>
39 #include <linux/bit_spinlock.h>
40 #include <linux/security.h>
41 #include <linux/version.h>
42 #include <linux/xattr.h>
43 #include <linux/vmalloc.h>
44 #include "compat.h"
45 #include "ctree.h"
46 #include "disk-io.h"
47 #include "transaction.h"
48 #include "btrfs_inode.h"
49 #include "ioctl.h"
50 #include "print-tree.h"
51 #include "volumes.h"
52 #include "locking.h"
53
54
55
56 static noinline int create_subvol(struct btrfs_root *root,
57 struct dentry *dentry,
58 char *name, int namelen)
59 {
60 struct btrfs_trans_handle *trans;
61 struct btrfs_key key;
62 struct btrfs_root_item root_item;
63 struct btrfs_inode_item *inode_item;
64 struct extent_buffer *leaf;
65 struct btrfs_root *new_root = root;
66 struct inode *dir;
67 int ret;
68 int err;
69 u64 objectid;
70 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
71 u64 index = 0;
72 unsigned long nr = 1;
73
74 ret = btrfs_check_free_space(root, 1, 0);
75 if (ret)
76 goto fail_commit;
77
78 trans = btrfs_start_transaction(root, 1);
79 BUG_ON(!trans);
80
81 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
82 0, &objectid);
83 if (ret)
84 goto fail;
85
86 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
87 objectid, trans->transid, 0, 0, 0);
88 if (IS_ERR(leaf)) {
89 ret = PTR_ERR(leaf);
90 goto fail;
91 }
92
93 btrfs_set_header_nritems(leaf, 0);
94 btrfs_set_header_level(leaf, 0);
95 btrfs_set_header_bytenr(leaf, leaf->start);
96 btrfs_set_header_generation(leaf, trans->transid);
97 btrfs_set_header_owner(leaf, objectid);
98
99 write_extent_buffer(leaf, root->fs_info->fsid,
100 (unsigned long)btrfs_header_fsid(leaf),
101 BTRFS_FSID_SIZE);
102 btrfs_mark_buffer_dirty(leaf);
103
104 inode_item = &root_item.inode;
105 memset(inode_item, 0, sizeof(*inode_item));
106 inode_item->generation = cpu_to_le64(1);
107 inode_item->size = cpu_to_le64(3);
108 inode_item->nlink = cpu_to_le32(1);
109 inode_item->nbytes = cpu_to_le64(root->leafsize);
110 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
111
112 btrfs_set_root_bytenr(&root_item, leaf->start);
113 btrfs_set_root_generation(&root_item, trans->transid);
114 btrfs_set_root_level(&root_item, 0);
115 btrfs_set_root_refs(&root_item, 1);
116 btrfs_set_root_used(&root_item, 0);
117 btrfs_set_root_last_snapshot(&root_item, 0);
118
119 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
120 root_item.drop_level = 0;
121
122 btrfs_tree_unlock(leaf);
123 free_extent_buffer(leaf);
124 leaf = NULL;
125
126 btrfs_set_root_dirid(&root_item, new_dirid);
127
128 key.objectid = objectid;
129 key.offset = 1;
130 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
131 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
132 &root_item);
133 if (ret)
134 goto fail;
135
136 /*
137 * insert the directory item
138 */
139 key.offset = (u64)-1;
140 dir = dentry->d_parent->d_inode;
141 ret = btrfs_set_inode_index(dir, &index);
142 BUG_ON(ret);
143
144 ret = btrfs_insert_dir_item(trans, root,
145 name, namelen, dir->i_ino, &key,
146 BTRFS_FT_DIR, index);
147 if (ret)
148 goto fail;
149
150 /* add the backref first */
151 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
152 objectid, BTRFS_ROOT_BACKREF_KEY,
153 root->root_key.objectid,
154 dir->i_ino, index, name, namelen);
155
156 BUG_ON(ret);
157
158 /* now add the forward ref */
159 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
160 root->root_key.objectid, BTRFS_ROOT_REF_KEY,
161 objectid,
162 dir->i_ino, index, name, namelen);
163
164 BUG_ON(ret);
165
166 ret = btrfs_commit_transaction(trans, root);
167 if (ret)
168 goto fail_commit;
169
170 new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
171 BUG_ON(!new_root);
172
173 trans = btrfs_start_transaction(new_root, 1);
174 BUG_ON(!trans);
175
176 ret = btrfs_create_subvol_root(new_root, dentry, trans, new_dirid,
177 BTRFS_I(dir)->block_group);
178 if (ret)
179 goto fail;
180
181 fail:
182 nr = trans->blocks_used;
183 err = btrfs_commit_transaction(trans, new_root);
184 if (err && !ret)
185 ret = err;
186 fail_commit:
187 btrfs_btree_balance_dirty(root, nr);
188 return ret;
189 }
190
191 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
192 char *name, int namelen)
193 {
194 struct btrfs_pending_snapshot *pending_snapshot;
195 struct btrfs_trans_handle *trans;
196 int ret = 0;
197 int err;
198 unsigned long nr = 0;
199
200 if (!root->ref_cows)
201 return -EINVAL;
202
203 ret = btrfs_check_free_space(root, 1, 0);
204 if (ret)
205 goto fail_unlock;
206
207 pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
208 if (!pending_snapshot) {
209 ret = -ENOMEM;
210 goto fail_unlock;
211 }
212 pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
213 if (!pending_snapshot->name) {
214 ret = -ENOMEM;
215 kfree(pending_snapshot);
216 goto fail_unlock;
217 }
218 memcpy(pending_snapshot->name, name, namelen);
219 pending_snapshot->name[namelen] = '\0';
220 pending_snapshot->dentry = dentry;
221 trans = btrfs_start_transaction(root, 1);
222 BUG_ON(!trans);
223 pending_snapshot->root = root;
224 list_add(&pending_snapshot->list,
225 &trans->transaction->pending_snapshots);
226 err = btrfs_commit_transaction(trans, root);
227
228 fail_unlock:
229 btrfs_btree_balance_dirty(root, nr);
230 return ret;
231 }
232
233 /* copy of may_create in fs/namei.c() */
234 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
235 {
236 if (child->d_inode)
237 return -EEXIST;
238 if (IS_DEADDIR(dir))
239 return -ENOENT;
240 return inode_permission(dir, MAY_WRITE | MAY_EXEC);
241 }
242
243 /*
244 * Create a new subvolume below @parent. This is largely modeled after
245 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
246 * inside this filesystem so it's quite a bit simpler.
247 */
248 static noinline int btrfs_mksubvol(struct path *parent, char *name,
249 int mode, int namelen,
250 struct btrfs_root *snap_src)
251 {
252 struct dentry *dentry;
253 int error;
254
255 mutex_lock_nested(&parent->dentry->d_inode->i_mutex, I_MUTEX_PARENT);
256
257 dentry = lookup_one_len(name, parent->dentry, namelen);
258 error = PTR_ERR(dentry);
259 if (IS_ERR(dentry))
260 goto out_unlock;
261
262 error = -EEXIST;
263 if (dentry->d_inode)
264 goto out_dput;
265
266 if (!IS_POSIXACL(parent->dentry->d_inode))
267 mode &= ~current->fs->umask;
268
269 error = mnt_want_write(parent->mnt);
270 if (error)
271 goto out_dput;
272
273 error = btrfs_may_create(parent->dentry->d_inode, dentry);
274 if (error)
275 goto out_drop_write;
276
277 /*
278 * Actually perform the low-level subvolume creation after all
279 * this VFS fuzz.
280 *
281 * Eventually we want to pass in an inode under which we create this
282 * subvolume, but for now all are under the filesystem root.
283 *
284 * Also we should pass on the mode eventually to allow creating new
285 * subvolume with specific mode bits.
286 */
287 if (snap_src) {
288 struct dentry *dir = dentry->d_parent;
289 struct dentry *test = dir->d_parent;
290 struct btrfs_path *path = btrfs_alloc_path();
291 int ret;
292 u64 test_oid;
293 u64 parent_oid = BTRFS_I(dir->d_inode)->root->root_key.objectid;
294
295 test_oid = snap_src->root_key.objectid;
296
297 ret = btrfs_find_root_ref(snap_src->fs_info->tree_root,
298 path, parent_oid, test_oid);
299 if (ret == 0)
300 goto create;
301 btrfs_release_path(snap_src->fs_info->tree_root, path);
302
303 /* we need to make sure we aren't creating a directory loop
304 * by taking a snapshot of something that has our current
305 * subvol in its directory tree. So, this loops through
306 * the dentries and checks the forward refs for each subvolume
307 * to see if is references the subvolume where we are
308 * placing this new snapshot.
309 */
310 while(1) {
311 if (!test ||
312 dir == snap_src->fs_info->sb->s_root ||
313 test == snap_src->fs_info->sb->s_root ||
314 test->d_inode->i_sb != snap_src->fs_info->sb) {
315 break;
316 }
317 if (S_ISLNK(test->d_inode->i_mode)) {
318 printk("Symlink in snapshot path, failed\n");
319 error = -EMLINK;
320 btrfs_free_path(path);
321 goto out_drop_write;
322 }
323 test_oid =
324 BTRFS_I(test->d_inode)->root->root_key.objectid;
325 ret = btrfs_find_root_ref(snap_src->fs_info->tree_root,
326 path, test_oid, parent_oid);
327 if (ret == 0) {
328 printk("Snapshot creation failed, looping\n");
329 error = -EMLINK;
330 btrfs_free_path(path);
331 goto out_drop_write;
332 }
333 btrfs_release_path(snap_src->fs_info->tree_root, path);
334 test = test->d_parent;
335 }
336 create:
337 btrfs_free_path(path);
338 error = create_snapshot(snap_src, dentry, name, namelen);
339 } else {
340 error = create_subvol(BTRFS_I(parent->dentry->d_inode)->root,
341 dentry, name, namelen);
342 }
343 if (error)
344 goto out_drop_write;
345
346 fsnotify_mkdir(parent->dentry->d_inode, dentry);
347 out_drop_write:
348 mnt_drop_write(parent->mnt);
349 out_dput:
350 dput(dentry);
351 out_unlock:
352 mutex_unlock(&parent->dentry->d_inode->i_mutex);
353 return error;
354 }
355
356
357 static int btrfs_defrag_file(struct file *file)
358 {
359 struct inode *inode = fdentry(file)->d_inode;
360 struct btrfs_root *root = BTRFS_I(inode)->root;
361 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
362 struct btrfs_ordered_extent *ordered;
363 struct page *page;
364 unsigned long last_index;
365 unsigned long ra_pages = root->fs_info->bdi.ra_pages;
366 unsigned long total_read = 0;
367 u64 page_start;
368 u64 page_end;
369 unsigned long i;
370 int ret;
371
372 ret = btrfs_check_free_space(root, inode->i_size, 0);
373 if (ret)
374 return -ENOSPC;
375
376 mutex_lock(&inode->i_mutex);
377 last_index = inode->i_size >> PAGE_CACHE_SHIFT;
378 for (i = 0; i <= last_index; i++) {
379 if (total_read % ra_pages == 0) {
380 btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
381 min(last_index, i + ra_pages - 1));
382 }
383 total_read++;
384 again:
385 page = grab_cache_page(inode->i_mapping, i);
386 if (!page)
387 goto out_unlock;
388 if (!PageUptodate(page)) {
389 btrfs_readpage(NULL, page);
390 lock_page(page);
391 if (!PageUptodate(page)) {
392 unlock_page(page);
393 page_cache_release(page);
394 goto out_unlock;
395 }
396 }
397
398 wait_on_page_writeback(page);
399
400 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
401 page_end = page_start + PAGE_CACHE_SIZE - 1;
402 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
403
404 ordered = btrfs_lookup_ordered_extent(inode, page_start);
405 if (ordered) {
406 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
407 unlock_page(page);
408 page_cache_release(page);
409 btrfs_start_ordered_extent(inode, ordered, 1);
410 btrfs_put_ordered_extent(ordered);
411 goto again;
412 }
413 set_page_extent_mapped(page);
414
415 /*
416 * this makes sure page_mkwrite is called on the
417 * page if it is dirtied again later
418 */
419 clear_page_dirty_for_io(page);
420
421 btrfs_set_extent_delalloc(inode, page_start, page_end);
422
423 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
424 set_page_dirty(page);
425 unlock_page(page);
426 page_cache_release(page);
427 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
428 }
429
430 out_unlock:
431 mutex_unlock(&inode->i_mutex);
432 return 0;
433 }
434
435 /*
436 * Called inside transaction, so use GFP_NOFS
437 */
438
439 static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
440 {
441 u64 new_size;
442 u64 old_size;
443 u64 devid = 1;
444 struct btrfs_ioctl_vol_args *vol_args;
445 struct btrfs_trans_handle *trans;
446 struct btrfs_device *device = NULL;
447 char *sizestr;
448 char *devstr = NULL;
449 int ret = 0;
450 int namelen;
451 int mod = 0;
452
453 if (root->fs_info->sb->s_flags & MS_RDONLY)
454 return -EROFS;
455
456 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
457
458 if (!vol_args)
459 return -ENOMEM;
460
461 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
462 ret = -EFAULT;
463 goto out;
464 }
465
466 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
467 namelen = strlen(vol_args->name);
468
469 mutex_lock(&root->fs_info->volume_mutex);
470 sizestr = vol_args->name;
471 devstr = strchr(sizestr, ':');
472 if (devstr) {
473 char *end;
474 sizestr = devstr + 1;
475 *devstr = '\0';
476 devstr = vol_args->name;
477 devid = simple_strtoull(devstr, &end, 10);
478 printk(KERN_INFO "resizing devid %llu\n", devid);
479 }
480 device = btrfs_find_device(root, devid, NULL, NULL);
481 if (!device) {
482 printk(KERN_INFO "resizer unable to find device %llu\n", devid);
483 ret = -EINVAL;
484 goto out_unlock;
485 }
486 if (!strcmp(sizestr, "max"))
487 new_size = device->bdev->bd_inode->i_size;
488 else {
489 if (sizestr[0] == '-') {
490 mod = -1;
491 sizestr++;
492 } else if (sizestr[0] == '+') {
493 mod = 1;
494 sizestr++;
495 }
496 new_size = btrfs_parse_size(sizestr);
497 if (new_size == 0) {
498 ret = -EINVAL;
499 goto out_unlock;
500 }
501 }
502
503 old_size = device->total_bytes;
504
505 if (mod < 0) {
506 if (new_size > old_size) {
507 ret = -EINVAL;
508 goto out_unlock;
509 }
510 new_size = old_size - new_size;
511 } else if (mod > 0) {
512 new_size = old_size + new_size;
513 }
514
515 if (new_size < 256 * 1024 * 1024) {
516 ret = -EINVAL;
517 goto out_unlock;
518 }
519 if (new_size > device->bdev->bd_inode->i_size) {
520 ret = -EFBIG;
521 goto out_unlock;
522 }
523
524 do_div(new_size, root->sectorsize);
525 new_size *= root->sectorsize;
526
527 printk(KERN_INFO "new size for %s is %llu\n",
528 device->name, (unsigned long long)new_size);
529
530 if (new_size > old_size) {
531 trans = btrfs_start_transaction(root, 1);
532 ret = btrfs_grow_device(trans, device, new_size);
533 btrfs_commit_transaction(trans, root);
534 } else {
535 ret = btrfs_shrink_device(device, new_size);
536 }
537
538 out_unlock:
539 mutex_unlock(&root->fs_info->volume_mutex);
540 out:
541 kfree(vol_args);
542 return ret;
543 }
544
545 static noinline int btrfs_ioctl_snap_create(struct file *file,
546 void __user *arg, int subvol)
547 {
548 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
549 struct btrfs_ioctl_vol_args *vol_args;
550 struct btrfs_dir_item *di;
551 struct btrfs_path *path;
552 struct file *src_file;
553 u64 root_dirid;
554 int namelen;
555 int ret = 0;
556
557 if (root->fs_info->sb->s_flags & MS_RDONLY)
558 return -EROFS;
559
560 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
561
562 if (!vol_args)
563 return -ENOMEM;
564
565 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
566 ret = -EFAULT;
567 goto out;
568 }
569
570 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
571 namelen = strlen(vol_args->name);
572 if (strchr(vol_args->name, '/')) {
573 ret = -EINVAL;
574 goto out;
575 }
576
577 path = btrfs_alloc_path();
578 if (!path) {
579 ret = -ENOMEM;
580 goto out;
581 }
582
583 root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
584 di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
585 path, root_dirid,
586 vol_args->name, namelen, 0);
587 btrfs_free_path(path);
588
589 if (di && !IS_ERR(di)) {
590 ret = -EEXIST;
591 goto out;
592 }
593
594 if (IS_ERR(di)) {
595 ret = PTR_ERR(di);
596 goto out;
597 }
598
599 if (subvol) {
600 ret = btrfs_mksubvol(&file->f_path, vol_args->name,
601 file->f_path.dentry->d_inode->i_mode,
602 namelen, NULL);
603 } else {
604 struct inode *src_inode;
605 src_file = fget(vol_args->fd);
606 if (!src_file) {
607 ret = -EINVAL;
608 goto out;
609 }
610
611 src_inode = src_file->f_path.dentry->d_inode;
612 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
613 printk("btrfs: Snapshot src from another FS\n");
614 ret = -EINVAL;
615 fput(src_file);
616 goto out;
617 }
618 ret = btrfs_mksubvol(&file->f_path, vol_args->name,
619 file->f_path.dentry->d_inode->i_mode,
620 namelen, BTRFS_I(src_inode)->root);
621 fput(src_file);
622 }
623
624 out:
625 kfree(vol_args);
626 return ret;
627 }
628
629 static int btrfs_ioctl_defrag(struct file *file)
630 {
631 struct inode *inode = fdentry(file)->d_inode;
632 struct btrfs_root *root = BTRFS_I(inode)->root;
633 int ret;
634
635 ret = mnt_want_write(file->f_path.mnt);
636 if (ret)
637 return ret;
638
639 switch (inode->i_mode & S_IFMT) {
640 case S_IFDIR:
641 btrfs_defrag_root(root, 0);
642 btrfs_defrag_root(root->fs_info->extent_root, 0);
643 break;
644 case S_IFREG:
645 btrfs_defrag_file(file);
646 break;
647 }
648
649 return 0;
650 }
651
652 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
653 {
654 struct btrfs_ioctl_vol_args *vol_args;
655 int ret;
656
657 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
658
659 if (!vol_args)
660 return -ENOMEM;
661
662 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
663 ret = -EFAULT;
664 goto out;
665 }
666 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
667 ret = btrfs_init_new_device(root, vol_args->name);
668
669 out:
670 kfree(vol_args);
671 return ret;
672 }
673
674 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
675 {
676 struct btrfs_ioctl_vol_args *vol_args;
677 int ret;
678
679 if (root->fs_info->sb->s_flags & MS_RDONLY)
680 return -EROFS;
681
682 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
683
684 if (!vol_args)
685 return -ENOMEM;
686
687 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
688 ret = -EFAULT;
689 goto out;
690 }
691 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
692 ret = btrfs_rm_device(root, vol_args->name);
693
694 out:
695 kfree(vol_args);
696 return ret;
697 }
698
699 static long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
700 u64 off, u64 olen, u64 destoff)
701 {
702 struct inode *inode = fdentry(file)->d_inode;
703 struct btrfs_root *root = BTRFS_I(inode)->root;
704 struct file *src_file;
705 struct inode *src;
706 struct btrfs_trans_handle *trans;
707 struct btrfs_path *path;
708 struct extent_buffer *leaf;
709 char *buf;
710 struct btrfs_key key;
711 u32 nritems;
712 int slot;
713 int ret;
714 u64 len = olen;
715 u64 bs = root->fs_info->sb->s_blocksize;
716 u64 hint_byte;
717
718 /*
719 * TODO:
720 * - split compressed inline extents. annoying: we need to
721 * decompress into destination's address_space (the file offset
722 * may change, so source mapping won't do), then recompress (or
723 * otherwise reinsert) a subrange.
724 * - allow ranges within the same file to be cloned (provided
725 * they don't overlap)?
726 */
727
728 ret = mnt_want_write(file->f_path.mnt);
729 if (ret)
730 return ret;
731
732 src_file = fget(srcfd);
733 if (!src_file)
734 return -EBADF;
735 src = src_file->f_dentry->d_inode;
736
737 ret = -EINVAL;
738 if (src == inode)
739 goto out_fput;
740
741 ret = -EISDIR;
742 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
743 goto out_fput;
744
745 ret = -EXDEV;
746 if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
747 goto out_fput;
748
749 ret = -ENOMEM;
750 buf = vmalloc(btrfs_level_size(root, 0));
751 if (!buf)
752 goto out_fput;
753
754 path = btrfs_alloc_path();
755 if (!path) {
756 vfree(buf);
757 goto out_fput;
758 }
759 path->reada = 2;
760
761 if (inode < src) {
762 mutex_lock(&inode->i_mutex);
763 mutex_lock(&src->i_mutex);
764 } else {
765 mutex_lock(&src->i_mutex);
766 mutex_lock(&inode->i_mutex);
767 }
768
769 /* determine range to clone */
770 ret = -EINVAL;
771 if (off >= src->i_size || off + len > src->i_size)
772 goto out_unlock;
773 if (len == 0)
774 olen = len = src->i_size - off;
775 /* if we extend to eof, continue to block boundary */
776 if (off + len == src->i_size)
777 len = ((src->i_size + bs-1) & ~(bs-1))
778 - off;
779
780 /* verify the end result is block aligned */
781 if ((off & (bs-1)) ||
782 ((off + len) & (bs-1)))
783 goto out_unlock;
784
785 printk("final src extent is %llu~%llu\n", off, len);
786 printk("final dst extent is %llu~%llu\n", destoff, len);
787
788 /* do any pending delalloc/csum calc on src, one way or
789 another, and lock file content */
790 while (1) {
791 struct btrfs_ordered_extent *ordered;
792 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
793 ordered = btrfs_lookup_first_ordered_extent(inode, off+len);
794 if (BTRFS_I(src)->delalloc_bytes == 0 && !ordered)
795 break;
796 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
797 if (ordered)
798 btrfs_put_ordered_extent(ordered);
799 btrfs_wait_ordered_range(src, off, off+len);
800 }
801
802 trans = btrfs_start_transaction(root, 1);
803 BUG_ON(!trans);
804
805 /* punch hole in destination first */
806 btrfs_drop_extents(trans, root, inode, off, off+len, 0, &hint_byte);
807
808 /* clone data */
809 key.objectid = src->i_ino;
810 key.type = BTRFS_EXTENT_DATA_KEY;
811 key.offset = 0;
812
813 while (1) {
814 /*
815 * note the key will change type as we walk through the
816 * tree.
817 */
818 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
819 if (ret < 0)
820 goto out;
821
822 nritems = btrfs_header_nritems(path->nodes[0]);
823 if (path->slots[0] >= nritems) {
824 ret = btrfs_next_leaf(root, path);
825 if (ret < 0)
826 goto out;
827 if (ret > 0)
828 break;
829 nritems = btrfs_header_nritems(path->nodes[0]);
830 }
831 leaf = path->nodes[0];
832 slot = path->slots[0];
833
834 btrfs_item_key_to_cpu(leaf, &key, slot);
835 if (btrfs_key_type(&key) > BTRFS_CSUM_ITEM_KEY ||
836 key.objectid != src->i_ino)
837 break;
838
839 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
840 struct btrfs_file_extent_item *extent;
841 int type;
842 u32 size;
843 struct btrfs_key new_key;
844 u64 disko = 0, diskl = 0;
845 u64 datao = 0, datal = 0;
846 u8 comp;
847
848 size = btrfs_item_size_nr(leaf, slot);
849 read_extent_buffer(leaf, buf,
850 btrfs_item_ptr_offset(leaf, slot),
851 size);
852
853 extent = btrfs_item_ptr(leaf, slot,
854 struct btrfs_file_extent_item);
855 comp = btrfs_file_extent_compression(leaf, extent);
856 type = btrfs_file_extent_type(leaf, extent);
857 if (type == BTRFS_FILE_EXTENT_REG) {
858 disko = btrfs_file_extent_disk_bytenr(leaf, extent);
859 diskl = btrfs_file_extent_disk_num_bytes(leaf, extent);
860 datao = btrfs_file_extent_offset(leaf, extent);
861 datal = btrfs_file_extent_num_bytes(leaf, extent);
862 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
863 /* take upper bound, may be compressed */
864 datal = btrfs_file_extent_ram_bytes(leaf,
865 extent);
866 }
867 btrfs_release_path(root, path);
868
869 if (key.offset + datal < off ||
870 key.offset >= off+len)
871 goto next;
872
873 memcpy(&new_key, &key, sizeof(new_key));
874 new_key.objectid = inode->i_ino;
875 new_key.offset = key.offset + destoff - off;
876
877 if (type == BTRFS_FILE_EXTENT_REG) {
878 ret = btrfs_insert_empty_item(trans, root, path,
879 &new_key, size);
880 if (ret)
881 goto out;
882
883 leaf = path->nodes[0];
884 slot = path->slots[0];
885 write_extent_buffer(leaf, buf,
886 btrfs_item_ptr_offset(leaf, slot),
887 size);
888
889 extent = btrfs_item_ptr(leaf, slot,
890 struct btrfs_file_extent_item);
891 printk(" orig disk %llu~%llu data %llu~%llu\n",
892 disko, diskl, datao, datal);
893
894 if (off > key.offset) {
895 datao += off - key.offset;
896 datal -= off - key.offset;
897 }
898 if (key.offset + datao + datal + key.offset >
899 off + len)
900 datal = off + len - key.offset - datao;
901 /* disko == 0 means it's a hole */
902 if (!disko)
903 datao = 0;
904 printk(" final disk %llu~%llu data %llu~%llu\n",
905 disko, diskl, datao, datal);
906
907 btrfs_set_file_extent_offset(leaf, extent,
908 datao);
909 btrfs_set_file_extent_num_bytes(leaf, extent,
910 datal);
911 if (disko) {
912 inode_add_bytes(inode, datal);
913 ret = btrfs_inc_extent_ref(trans, root,
914 disko, diskl, leaf->start,
915 root->root_key.objectid,
916 trans->transid,
917 inode->i_ino);
918 BUG_ON(ret);
919 }
920 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
921 u64 skip = 0;
922 u64 trim = 0;
923 if (off > key.offset) {
924 skip = off - key.offset;
925 new_key.offset += skip;
926 }
927 if (key.offset + datal > off+len)
928 trim = key.offset + datal - (off+len);
929 printk("len %lld skip %lld trim %lld\n",
930 datal, skip, trim);
931 if (comp && (skip || trim)) {
932 printk("btrfs clone_range can't split compressed inline extents yet\n");
933 ret = -EINVAL;
934 goto out;
935 }
936 size -= skip + trim;
937 datal -= skip + trim;
938 ret = btrfs_insert_empty_item(trans, root, path,
939 &new_key, size);
940 if (ret)
941 goto out;
942
943 if (skip) {
944 u32 start = btrfs_file_extent_calc_inline_size(0);
945 memmove(buf+start, buf+start+skip,
946 datal);
947 }
948
949 leaf = path->nodes[0];
950 slot = path->slots[0];
951 write_extent_buffer(leaf, buf,
952 btrfs_item_ptr_offset(leaf, slot),
953 size);
954 inode_add_bytes(inode, datal);
955 }
956
957 btrfs_mark_buffer_dirty(leaf);
958 }
959
960 if (btrfs_key_type(&key) == BTRFS_CSUM_ITEM_KEY) {
961 u32 size;
962 struct btrfs_key new_key;
963 u64 coverslen;
964 int coff, clen;
965
966 size = btrfs_item_size_nr(leaf, slot);
967 coverslen = (size / BTRFS_CRC32_SIZE) <<
968 root->fs_info->sb->s_blocksize_bits;
969 printk("csums for %llu~%llu\n",
970 key.offset, coverslen);
971 if (key.offset + coverslen < off ||
972 key.offset >= off+len)
973 goto next;
974
975 read_extent_buffer(leaf, buf,
976 btrfs_item_ptr_offset(leaf, slot),
977 size);
978 btrfs_release_path(root, path);
979
980 coff = 0;
981 if (off > key.offset)
982 coff = ((off - key.offset) >>
983 root->fs_info->sb->s_blocksize_bits) *
984 BTRFS_CRC32_SIZE;
985 clen = size - coff;
986 if (key.offset + coverslen > off+len)
987 clen -= ((key.offset+coverslen-off-len) >>
988 root->fs_info->sb->s_blocksize_bits) *
989 BTRFS_CRC32_SIZE;
990 printk(" will dup %d~%d of %d\n",
991 coff, clen, size);
992
993 memcpy(&new_key, &key, sizeof(new_key));
994 new_key.objectid = inode->i_ino;
995 new_key.offset = key.offset + destoff - off;
996
997 ret = btrfs_insert_empty_item(trans, root, path,
998 &new_key, clen);
999 if (ret)
1000 goto out;
1001
1002 leaf = path->nodes[0];
1003 slot = path->slots[0];
1004 write_extent_buffer(leaf, buf + coff,
1005 btrfs_item_ptr_offset(leaf, slot),
1006 clen);
1007 btrfs_mark_buffer_dirty(leaf);
1008 }
1009
1010 next:
1011 btrfs_release_path(root, path);
1012 key.offset++;
1013 }
1014 ret = 0;
1015 out:
1016 btrfs_release_path(root, path);
1017 if (ret == 0) {
1018 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1019 if (destoff + olen > inode->i_size)
1020 btrfs_i_size_write(inode, destoff + olen);
1021 BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
1022 ret = btrfs_update_inode(trans, root, inode);
1023 }
1024 btrfs_end_transaction(trans, root);
1025 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1026 if (ret)
1027 vmtruncate(inode, 0);
1028 out_unlock:
1029 mutex_unlock(&src->i_mutex);
1030 mutex_unlock(&inode->i_mutex);
1031 vfree(buf);
1032 btrfs_free_path(path);
1033 out_fput:
1034 fput(src_file);
1035 return ret;
1036 }
1037
1038 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
1039 {
1040 struct btrfs_ioctl_clone_range_args args;
1041
1042 if (copy_from_user(&args, argp, sizeof(args)))
1043 return -EFAULT;
1044 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
1045 args.src_length, args.dest_offset);
1046 }
1047
1048 /*
1049 * there are many ways the trans_start and trans_end ioctls can lead
1050 * to deadlocks. They should only be used by applications that
1051 * basically own the machine, and have a very in depth understanding
1052 * of all the possible deadlocks and enospc problems.
1053 */
1054 static long btrfs_ioctl_trans_start(struct file *file)
1055 {
1056 struct inode *inode = fdentry(file)->d_inode;
1057 struct btrfs_root *root = BTRFS_I(inode)->root;
1058 struct btrfs_trans_handle *trans;
1059 int ret = 0;
1060
1061 if (!capable(CAP_SYS_ADMIN))
1062 return -EPERM;
1063
1064 if (file->private_data) {
1065 ret = -EINPROGRESS;
1066 goto out;
1067 }
1068
1069 ret = mnt_want_write(file->f_path.mnt);
1070 if (ret)
1071 goto out;
1072
1073 mutex_lock(&root->fs_info->trans_mutex);
1074 root->fs_info->open_ioctl_trans++;
1075 mutex_unlock(&root->fs_info->trans_mutex);
1076
1077 trans = btrfs_start_ioctl_transaction(root, 0);
1078 if (trans)
1079 file->private_data = trans;
1080 else
1081 ret = -ENOMEM;
1082 /*printk(KERN_INFO "btrfs_ioctl_trans_start on %p\n", file);*/
1083 out:
1084 return ret;
1085 }
1086
1087 /*
1088 * there are many ways the trans_start and trans_end ioctls can lead
1089 * to deadlocks. They should only be used by applications that
1090 * basically own the machine, and have a very in depth understanding
1091 * of all the possible deadlocks and enospc problems.
1092 */
1093 long btrfs_ioctl_trans_end(struct file *file)
1094 {
1095 struct inode *inode = fdentry(file)->d_inode;
1096 struct btrfs_root *root = BTRFS_I(inode)->root;
1097 struct btrfs_trans_handle *trans;
1098 int ret = 0;
1099
1100 trans = file->private_data;
1101 if (!trans) {
1102 ret = -EINVAL;
1103 goto out;
1104 }
1105 btrfs_end_transaction(trans, root);
1106 file->private_data = NULL;
1107
1108 mutex_lock(&root->fs_info->trans_mutex);
1109 root->fs_info->open_ioctl_trans--;
1110 mutex_unlock(&root->fs_info->trans_mutex);
1111
1112 out:
1113 return ret;
1114 }
1115
1116 long btrfs_ioctl(struct file *file, unsigned int
1117 cmd, unsigned long arg)
1118 {
1119 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
1120 void __user *argp = (void __user *)arg;
1121
1122 switch (cmd) {
1123 case BTRFS_IOC_SNAP_CREATE:
1124 return btrfs_ioctl_snap_create(file, argp, 0);
1125 case BTRFS_IOC_SUBVOL_CREATE:
1126 return btrfs_ioctl_snap_create(file, argp, 1);
1127 case BTRFS_IOC_DEFRAG:
1128 return btrfs_ioctl_defrag(file);
1129 case BTRFS_IOC_RESIZE:
1130 return btrfs_ioctl_resize(root, argp);
1131 case BTRFS_IOC_ADD_DEV:
1132 return btrfs_ioctl_add_dev(root, argp);
1133 case BTRFS_IOC_RM_DEV:
1134 return btrfs_ioctl_rm_dev(root, argp);
1135 case BTRFS_IOC_BALANCE:
1136 return btrfs_balance(root->fs_info->dev_root);
1137 case BTRFS_IOC_CLONE:
1138 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
1139 case BTRFS_IOC_CLONE_RANGE:
1140 return btrfs_ioctl_clone_range(file, argp);
1141 case BTRFS_IOC_TRANS_START:
1142 return btrfs_ioctl_trans_start(file);
1143 case BTRFS_IOC_TRANS_END:
1144 return btrfs_ioctl_trans_end(file);
1145 case BTRFS_IOC_SYNC:
1146 btrfs_sync_fs(file->f_dentry->d_sb, 1);
1147 return 0;
1148 }
1149
1150 return -ENOTTY;
1151 }
Linux kernel - Deliverables
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