Btrfs: Fix a few functions that exit without stopping their transaction
[linux-2.6] / 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/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/smp_lock.h>
30 #include <linux/backing-dev.h>
31 #include <linux/mpage.h>
32 #include <linux/swap.h>
33 #include <linux/writeback.h>
34 #include <linux/statfs.h>
35 #include <linux/compat.h>
36 #include <linux/bit_spinlock.h>
37 #include <linux/version.h>
38 #include <linux/xattr.h>
39 #include "ctree.h"
40 #include "disk-io.h"
41 #include "transaction.h"
42 #include "btrfs_inode.h"
43 #include "ioctl.h"
44 #include "print-tree.h"
45 #include "volumes.h"
46 #include "locking.h"
47
48
49
50 static noinline int create_subvol(struct btrfs_root *root, char *name,
51                                   int namelen)
52 {
53         struct btrfs_trans_handle *trans;
54         struct btrfs_key key;
55         struct btrfs_root_item root_item;
56         struct btrfs_inode_item *inode_item;
57         struct extent_buffer *leaf;
58         struct btrfs_root *new_root = root;
59         struct inode *dir;
60         int ret;
61         int err;
62         u64 objectid;
63         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
64         unsigned long nr = 1;
65
66         ret = btrfs_check_free_space(root, 1, 0);
67         if (ret)
68                 goto fail_commit;
69
70         trans = btrfs_start_transaction(root, 1);
71         BUG_ON(!trans);
72
73         ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
74                                        0, &objectid);
75         if (ret)
76                 goto fail;
77
78         leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
79                                       objectid, trans->transid, 0, 0,
80                                       0, 0);
81         if (IS_ERR(leaf)) {
82                 ret = PTR_ERR(leaf);
83                 goto fail;
84         }
85
86         btrfs_set_header_nritems(leaf, 0);
87         btrfs_set_header_level(leaf, 0);
88         btrfs_set_header_bytenr(leaf, leaf->start);
89         btrfs_set_header_generation(leaf, trans->transid);
90         btrfs_set_header_owner(leaf, objectid);
91
92         write_extent_buffer(leaf, root->fs_info->fsid,
93                             (unsigned long)btrfs_header_fsid(leaf),
94                             BTRFS_FSID_SIZE);
95         btrfs_mark_buffer_dirty(leaf);
96
97         inode_item = &root_item.inode;
98         memset(inode_item, 0, sizeof(*inode_item));
99         inode_item->generation = cpu_to_le64(1);
100         inode_item->size = cpu_to_le64(3);
101         inode_item->nlink = cpu_to_le32(1);
102         inode_item->nblocks = cpu_to_le64(1);
103         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
104
105         btrfs_set_root_bytenr(&root_item, leaf->start);
106         btrfs_set_root_level(&root_item, 0);
107         btrfs_set_root_refs(&root_item, 1);
108         btrfs_set_root_used(&root_item, 0);
109
110         memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
111         root_item.drop_level = 0;
112
113         btrfs_tree_unlock(leaf);
114         free_extent_buffer(leaf);
115         leaf = NULL;
116
117         btrfs_set_root_dirid(&root_item, new_dirid);
118
119         key.objectid = objectid;
120         key.offset = 1;
121         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
122         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
123                                 &root_item);
124         if (ret)
125                 goto fail;
126
127         /*
128          * insert the directory item
129          */
130         key.offset = (u64)-1;
131         dir = root->fs_info->sb->s_root->d_inode;
132         ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
133                                     name, namelen, dir->i_ino, &key,
134                                     BTRFS_FT_DIR, 0);
135         if (ret)
136                 goto fail;
137
138         ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
139                              name, namelen, objectid,
140                              root->fs_info->sb->s_root->d_inode->i_ino, 0);
141         if (ret)
142                 goto fail;
143
144         ret = btrfs_commit_transaction(trans, root);
145         if (ret)
146                 goto fail_commit;
147
148         new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
149         BUG_ON(!new_root);
150
151         trans = btrfs_start_transaction(new_root, 1);
152         BUG_ON(!trans);
153
154         ret = btrfs_create_subvol_root(new_root, trans, new_dirid,
155                                        BTRFS_I(dir)->block_group);
156         if (ret)
157                 goto fail;
158
159         /* Invalidate existing dcache entry for new subvolume. */
160         btrfs_invalidate_dcache_root(root, name, namelen);
161
162 fail:
163         nr = trans->blocks_used;
164         err = btrfs_commit_transaction(trans, new_root);
165         if (err && !ret)
166                 ret = err;
167 fail_commit:
168         btrfs_btree_balance_dirty(root, nr);
169         return ret;
170 }
171
172 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
173 {
174         struct btrfs_pending_snapshot *pending_snapshot;
175         struct btrfs_trans_handle *trans;
176         int ret;
177         int err;
178         unsigned long nr = 0;
179
180         if (!root->ref_cows)
181                 return -EINVAL;
182
183         ret = btrfs_check_free_space(root, 1, 0);
184         if (ret)
185                 goto fail_unlock;
186
187         pending_snapshot = kmalloc(sizeof(*pending_snapshot), GFP_NOFS);
188         if (!pending_snapshot) {
189                 ret = -ENOMEM;
190                 goto fail_unlock;
191         }
192         pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
193         if (!pending_snapshot->name) {
194                 ret = -ENOMEM;
195                 kfree(pending_snapshot);
196                 goto fail_unlock;
197         }
198         memcpy(pending_snapshot->name, name, namelen);
199         pending_snapshot->name[namelen] = '\0';
200         trans = btrfs_start_transaction(root, 1);
201         BUG_ON(!trans);
202         pending_snapshot->root = root;
203         list_add(&pending_snapshot->list,
204                  &trans->transaction->pending_snapshots);
205         ret = btrfs_update_inode(trans, root, root->inode);
206         err = btrfs_commit_transaction(trans, root);
207
208 fail_unlock:
209         btrfs_btree_balance_dirty(root, nr);
210         return ret;
211 }
212
213 int btrfs_defrag_file(struct file *file)
214 {
215         struct inode *inode = fdentry(file)->d_inode;
216         struct btrfs_root *root = BTRFS_I(inode)->root;
217         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
218         struct btrfs_ordered_extent *ordered;
219         struct page *page;
220         unsigned long last_index;
221         unsigned long ra_pages = root->fs_info->bdi.ra_pages;
222         unsigned long total_read = 0;
223         u64 page_start;
224         u64 page_end;
225         unsigned long i;
226         int ret;
227
228         ret = btrfs_check_free_space(root, inode->i_size, 0);
229         if (ret)
230                 return -ENOSPC;
231
232         mutex_lock(&inode->i_mutex);
233         last_index = inode->i_size >> PAGE_CACHE_SHIFT;
234         for (i = 0; i <= last_index; i++) {
235                 if (total_read % ra_pages == 0) {
236                         btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
237                                        min(last_index, i + ra_pages - 1));
238                 }
239                 total_read++;
240 again:
241                 page = grab_cache_page(inode->i_mapping, i);
242                 if (!page)
243                         goto out_unlock;
244                 if (!PageUptodate(page)) {
245                         btrfs_readpage(NULL, page);
246                         lock_page(page);
247                         if (!PageUptodate(page)) {
248                                 unlock_page(page);
249                                 page_cache_release(page);
250                                 goto out_unlock;
251                         }
252                 }
253
254                 wait_on_page_writeback(page);
255
256                 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
257                 page_end = page_start + PAGE_CACHE_SIZE - 1;
258                 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
259
260                 ordered = btrfs_lookup_ordered_extent(inode, page_start);
261                 if (ordered) {
262                         unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
263                         unlock_page(page);
264                         page_cache_release(page);
265                         btrfs_start_ordered_extent(inode, ordered, 1);
266                         btrfs_put_ordered_extent(ordered);
267                         goto again;
268                 }
269                 set_page_extent_mapped(page);
270
271                 set_extent_delalloc(io_tree, page_start,
272                                     page_end, GFP_NOFS);
273
274                 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
275                 set_page_dirty(page);
276                 unlock_page(page);
277                 page_cache_release(page);
278                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
279         }
280
281 out_unlock:
282         mutex_unlock(&inode->i_mutex);
283         return 0;
284 }
285
286 /*
287  * Called inside transaction, so use GFP_NOFS
288  */
289
290 static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
291 {
292         u64 new_size;
293         u64 old_size;
294         u64 devid = 1;
295         struct btrfs_ioctl_vol_args *vol_args;
296         struct btrfs_trans_handle *trans;
297         struct btrfs_device *device = NULL;
298         char *sizestr;
299         char *devstr = NULL;
300         int ret = 0;
301         int namelen;
302         int mod = 0;
303
304         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
305
306         if (!vol_args)
307                 return -ENOMEM;
308
309         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
310                 ret = -EFAULT;
311                 goto out;
312         }
313         namelen = strlen(vol_args->name);
314         if (namelen > BTRFS_VOL_NAME_MAX) {
315                 ret = -EINVAL;
316                 goto out;
317         }
318
319         mutex_lock(&root->fs_info->volume_mutex);
320         sizestr = vol_args->name;
321         devstr = strchr(sizestr, ':');
322         if (devstr) {
323                 char *end;
324                 sizestr = devstr + 1;
325                 *devstr = '\0';
326                 devstr = vol_args->name;
327                 devid = simple_strtoull(devstr, &end, 10);
328                 printk(KERN_INFO "resizing devid %llu\n", devid);
329         }
330         device = btrfs_find_device(root, devid, NULL);
331         if (!device) {
332                 printk(KERN_INFO "resizer unable to find device %llu\n", devid);
333                 ret = -EINVAL;
334                 goto out_unlock;
335         }
336         if (!strcmp(sizestr, "max"))
337                 new_size = device->bdev->bd_inode->i_size;
338         else {
339                 if (sizestr[0] == '-') {
340                         mod = -1;
341                         sizestr++;
342                 } else if (sizestr[0] == '+') {
343                         mod = 1;
344                         sizestr++;
345                 }
346                 new_size = btrfs_parse_size(sizestr);
347                 if (new_size == 0) {
348                         ret = -EINVAL;
349                         goto out_unlock;
350                 }
351         }
352
353         old_size = device->total_bytes;
354
355         if (mod < 0) {
356                 if (new_size > old_size) {
357                         ret = -EINVAL;
358                         goto out_unlock;
359                 }
360                 new_size = old_size - new_size;
361         } else if (mod > 0) {
362                 new_size = old_size + new_size;
363         }
364
365         if (new_size < 256 * 1024 * 1024) {
366                 ret = -EINVAL;
367                 goto out_unlock;
368         }
369         if (new_size > device->bdev->bd_inode->i_size) {
370                 ret = -EFBIG;
371                 goto out_unlock;
372         }
373
374         do_div(new_size, root->sectorsize);
375         new_size *= root->sectorsize;
376
377         printk(KERN_INFO "new size for %s is %llu\n",
378                 device->name, (unsigned long long)new_size);
379
380         if (new_size > old_size) {
381                 trans = btrfs_start_transaction(root, 1);
382                 ret = btrfs_grow_device(trans, device, new_size);
383                 btrfs_commit_transaction(trans, root);
384         } else {
385                 ret = btrfs_shrink_device(device, new_size);
386         }
387
388 out_unlock:
389         mutex_unlock(&root->fs_info->volume_mutex);
390 out:
391         kfree(vol_args);
392         return ret;
393 }
394
395 static noinline int btrfs_ioctl_snap_create(struct btrfs_root *root,
396                                             void __user *arg)
397 {
398         struct btrfs_ioctl_vol_args *vol_args;
399         struct btrfs_dir_item *di;
400         struct btrfs_path *path;
401         u64 root_dirid;
402         int namelen;
403         int ret;
404
405         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
406
407         if (!vol_args)
408                 return -ENOMEM;
409
410         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
411                 ret = -EFAULT;
412                 goto out;
413         }
414
415         namelen = strlen(vol_args->name);
416         if (namelen > BTRFS_VOL_NAME_MAX) {
417                 ret = -EINVAL;
418                 goto out;
419         }
420         if (strchr(vol_args->name, '/')) {
421                 ret = -EINVAL;
422                 goto out;
423         }
424
425         path = btrfs_alloc_path();
426         if (!path) {
427                 ret = -ENOMEM;
428                 goto out;
429         }
430
431         root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
432         di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
433                             path, root_dirid,
434                             vol_args->name, namelen, 0);
435         btrfs_free_path(path);
436
437         if (di && !IS_ERR(di)) {
438                 ret = -EEXIST;
439                 goto out;
440         }
441
442         if (IS_ERR(di)) {
443                 ret = PTR_ERR(di);
444                 goto out;
445         }
446
447         mutex_lock(&root->fs_info->drop_mutex);
448         if (root == root->fs_info->tree_root)
449                 ret = create_subvol(root, vol_args->name, namelen);
450         else
451                 ret = create_snapshot(root, vol_args->name, namelen);
452         mutex_unlock(&root->fs_info->drop_mutex);
453 out:
454         kfree(vol_args);
455         return ret;
456 }
457
458 static int btrfs_ioctl_defrag(struct file *file)
459 {
460         struct inode *inode = fdentry(file)->d_inode;
461         struct btrfs_root *root = BTRFS_I(inode)->root;
462
463         switch (inode->i_mode & S_IFMT) {
464         case S_IFDIR:
465                 btrfs_defrag_root(root, 0);
466                 btrfs_defrag_root(root->fs_info->extent_root, 0);
467                 break;
468         case S_IFREG:
469                 btrfs_defrag_file(file);
470                 break;
471         }
472
473         return 0;
474 }
475
476 long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
477 {
478         struct btrfs_ioctl_vol_args *vol_args;
479         int ret;
480
481         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
482
483         if (!vol_args)
484                 return -ENOMEM;
485
486         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
487                 ret = -EFAULT;
488                 goto out;
489         }
490         ret = btrfs_init_new_device(root, vol_args->name);
491
492 out:
493         kfree(vol_args);
494         return ret;
495 }
496
497 long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
498 {
499         struct btrfs_ioctl_vol_args *vol_args;
500         int ret;
501
502         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
503
504         if (!vol_args)
505                 return -ENOMEM;
506
507         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
508                 ret = -EFAULT;
509                 goto out;
510         }
511         ret = btrfs_rm_device(root, vol_args->name);
512
513 out:
514         kfree(vol_args);
515         return ret;
516 }
517
518 int dup_item_to_inode(struct btrfs_trans_handle *trans,
519                        struct btrfs_root *root,
520                        struct btrfs_path *path,
521                        struct extent_buffer *leaf,
522                        int slot,
523                        struct btrfs_key *key,
524                        u64 destino)
525 {
526         char *dup;
527         int len = btrfs_item_size_nr(leaf, slot);
528         struct btrfs_key ckey = *key;
529         int ret = 0;
530
531         dup = kmalloc(len, GFP_NOFS);
532         if (!dup)
533                 return -ENOMEM;
534
535         read_extent_buffer(leaf, dup, btrfs_item_ptr_offset(leaf, slot), len);
536         btrfs_release_path(root, path);
537
538         ckey.objectid = destino;
539         ret = btrfs_insert_item(trans, root, &ckey, dup, len);
540         kfree(dup);
541         return ret;
542 }
543
544 long btrfs_ioctl_clone(struct file *file, unsigned long src_fd)
545 {
546         struct inode *inode = fdentry(file)->d_inode;
547         struct btrfs_root *root = BTRFS_I(inode)->root;
548         struct file *src_file;
549         struct inode *src;
550         struct btrfs_trans_handle *trans;
551         int ret;
552         u64 pos;
553         struct btrfs_path *path;
554         struct btrfs_key key;
555         struct extent_buffer *leaf;
556         u32 nritems;
557         int slot;
558
559         src_file = fget(src_fd);
560         if (!src_file)
561                 return -EBADF;
562         src = src_file->f_dentry->d_inode;
563
564         ret = -EXDEV;
565         if (src->i_sb != inode->i_sb)
566                 goto out_fput;
567
568         if (inode < src) {
569                 mutex_lock(&inode->i_mutex);
570                 mutex_lock(&src->i_mutex);
571         } else {
572                 mutex_lock(&src->i_mutex);
573                 mutex_lock(&inode->i_mutex);
574         }
575
576         ret = -ENOTEMPTY;
577         if (inode->i_size)
578                 goto out_unlock;
579
580         /* do any pending delalloc/csum calc on src, one way or
581            another, and lock file content */
582         while (1) {
583                 filemap_write_and_wait(src->i_mapping);
584                 lock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS);
585                 if (BTRFS_I(src)->delalloc_bytes == 0)
586                         break;
587                 unlock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS);
588         }
589
590         trans = btrfs_start_transaction(root, 0);
591         path = btrfs_alloc_path();
592         if (!path) {
593                 ret = -ENOMEM;
594                 goto out;
595         }
596         key.offset = 0;
597         key.type = BTRFS_EXTENT_DATA_KEY;
598         key.objectid = src->i_ino;
599         pos = 0;
600         path->reada = 2;
601
602         while (1) {
603                 /*
604                  * note the key will change type as we walk through the
605                  * tree.
606                  */
607                 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
608                 if (ret < 0)
609                         goto out;
610
611                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
612                         ret = btrfs_next_leaf(root, path);
613                         if (ret < 0)
614                                 goto out;
615                         if (ret > 0)
616                                 break;
617                 }
618                 leaf = path->nodes[0];
619                 slot = path->slots[0];
620                 btrfs_item_key_to_cpu(leaf, &key, slot);
621                 nritems = btrfs_header_nritems(leaf);
622
623                 if (btrfs_key_type(&key) > BTRFS_CSUM_ITEM_KEY ||
624                     key.objectid != src->i_ino)
625                         break;
626
627                 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
628                         struct btrfs_file_extent_item *extent;
629                         int found_type;
630                         pos = key.offset;
631                         extent = btrfs_item_ptr(leaf, slot,
632                                                 struct btrfs_file_extent_item);
633                         found_type = btrfs_file_extent_type(leaf, extent);
634                         if (found_type == BTRFS_FILE_EXTENT_REG) {
635                                 u64 len = btrfs_file_extent_num_bytes(leaf,
636                                                                       extent);
637                                 u64 ds = btrfs_file_extent_disk_bytenr(leaf,
638                                                                        extent);
639                                 u64 dl = btrfs_file_extent_disk_num_bytes(leaf,
640                                                                  extent);
641                                 u64 off = btrfs_file_extent_offset(leaf,
642                                                                    extent);
643                                 btrfs_insert_file_extent(trans, root,
644                                                          inode->i_ino, pos,
645                                                          ds, dl, len, off);
646                                 /* ds == 0 means there's a hole */
647                                 if (ds != 0) {
648                                         btrfs_inc_extent_ref(trans, root,
649                                                      ds, dl,
650                                                      root->root_key.objectid,
651                                                      trans->transid,
652                                                      inode->i_ino, pos);
653                                 }
654                                 pos = key.offset + len;
655                         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
656                                 ret = dup_item_to_inode(trans, root, path,
657                                                         leaf, slot, &key,
658                                                         inode->i_ino);
659                                 if (ret)
660                                         goto out;
661                                 pos = key.offset + btrfs_item_size_nr(leaf,
662                                                                       slot);
663                         }
664                 } else if (btrfs_key_type(&key) == BTRFS_CSUM_ITEM_KEY) {
665                         ret = dup_item_to_inode(trans, root, path, leaf,
666                                                 slot, &key, inode->i_ino);
667
668                         if (ret)
669                                 goto out;
670                 }
671                 key.offset++;
672                 btrfs_release_path(root, path);
673         }
674
675         ret = 0;
676 out:
677         btrfs_free_path(path);
678
679         inode->i_blocks = src->i_blocks;
680         i_size_write(inode, src->i_size);
681         btrfs_update_inode(trans, root, inode);
682
683         unlock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS);
684
685         btrfs_end_transaction(trans, root);
686
687 out_unlock:
688         mutex_unlock(&src->i_mutex);
689         mutex_unlock(&inode->i_mutex);
690 out_fput:
691         fput(src_file);
692         return ret;
693 }
694
695 /*
696  * there are many ways the trans_start and trans_end ioctls can lead
697  * to deadlocks.  They should only be used by applications that
698  * basically own the machine, and have a very in depth understanding
699  * of all the possible deadlocks and enospc problems.
700  */
701 long btrfs_ioctl_trans_start(struct file *file)
702 {
703         struct inode *inode = fdentry(file)->d_inode;
704         struct btrfs_root *root = BTRFS_I(inode)->root;
705         struct btrfs_trans_handle *trans;
706         int ret = 0;
707
708         if (!capable(CAP_SYS_ADMIN))
709                 return -EPERM;
710
711         if (file->private_data) {
712                 ret = -EINPROGRESS;
713                 goto out;
714         }
715         trans = btrfs_start_transaction(root, 0);
716         if (trans)
717                 file->private_data = trans;
718         else
719                 ret = -ENOMEM;
720         /*printk(KERN_INFO "btrfs_ioctl_trans_start on %p\n", file);*/
721 out:
722         return ret;
723 }
724
725 /*
726  * there are many ways the trans_start and trans_end ioctls can lead
727  * to deadlocks.  They should only be used by applications that
728  * basically own the machine, and have a very in depth understanding
729  * of all the possible deadlocks and enospc problems.
730  */
731 long btrfs_ioctl_trans_end(struct file *file)
732 {
733         struct inode *inode = fdentry(file)->d_inode;
734         struct btrfs_root *root = BTRFS_I(inode)->root;
735         struct btrfs_trans_handle *trans;
736         int ret = 0;
737
738         trans = file->private_data;
739         if (!trans) {
740                 ret = -EINVAL;
741                 goto out;
742         }
743         btrfs_end_transaction(trans, root);
744         file->private_data = 0;
745 out:
746         return ret;
747 }
748
749 long btrfs_ioctl(struct file *file, unsigned int
750                 cmd, unsigned long arg)
751 {
752         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
753
754         switch (cmd) {
755         case BTRFS_IOC_SNAP_CREATE:
756                 return btrfs_ioctl_snap_create(root, (void __user *)arg);
757         case BTRFS_IOC_DEFRAG:
758                 return btrfs_ioctl_defrag(file);
759         case BTRFS_IOC_RESIZE:
760                 return btrfs_ioctl_resize(root, (void __user *)arg);
761         case BTRFS_IOC_ADD_DEV:
762                 return btrfs_ioctl_add_dev(root, (void __user *)arg);
763         case BTRFS_IOC_RM_DEV:
764                 return btrfs_ioctl_rm_dev(root, (void __user *)arg);
765         case BTRFS_IOC_BALANCE:
766                 return btrfs_balance(root->fs_info->dev_root);
767         case BTRFS_IOC_CLONE:
768                 return btrfs_ioctl_clone(file, arg);
769         case BTRFS_IOC_TRANS_START:
770                 return btrfs_ioctl_trans_start(file);
771         case BTRFS_IOC_TRANS_END:
772                 return btrfs_ioctl_trans_end(file);
773         case BTRFS_IOC_SYNC:
774                 btrfs_sync_fs(file->f_dentry->d_sb, 1);
775                 return 0;
776         }
777
778         return -ENOTTY;
779 }