Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
[sfrench/cifs-2.6.git] / fs / btrfs / super.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/blkdev.h>
20 #include <linux/module.h>
21 #include <linux/buffer_head.h>
22 #include <linux/fs.h>
23 #include <linux/pagemap.h>
24 #include <linux/highmem.h>
25 #include <linux/time.h>
26 #include <linux/init.h>
27 #include <linux/seq_file.h>
28 #include <linux/string.h>
29 #include <linux/smp_lock.h>
30 #include <linux/backing-dev.h>
31 #include <linux/mount.h>
32 #include <linux/mpage.h>
33 #include <linux/swap.h>
34 #include <linux/writeback.h>
35 #include <linux/statfs.h>
36 #include <linux/compat.h>
37 #include <linux/parser.h>
38 #include <linux/ctype.h>
39 #include <linux/namei.h>
40 #include <linux/miscdevice.h>
41 #include <linux/magic.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 "xattr.h"
50 #include "volumes.h"
51 #include "version.h"
52 #include "export.h"
53 #include "compression.h"
54
55
56 static struct super_operations btrfs_super_ops;
57
58 static void btrfs_put_super(struct super_block *sb)
59 {
60         struct btrfs_root *root = btrfs_sb(sb);
61         int ret;
62
63         ret = close_ctree(root);
64         sb->s_fs_info = NULL;
65 }
66
67 enum {
68         Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow,
69         Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier,
70         Opt_ssd, Opt_thread_pool, Opt_noacl,  Opt_compress, Opt_notreelog,
71         Opt_ratio, Opt_flushoncommit, Opt_err,
72 };
73
74 static match_table_t tokens = {
75         {Opt_degraded, "degraded"},
76         {Opt_subvol, "subvol=%s"},
77         {Opt_device, "device=%s"},
78         {Opt_nodatasum, "nodatasum"},
79         {Opt_nodatacow, "nodatacow"},
80         {Opt_nobarrier, "nobarrier"},
81         {Opt_max_extent, "max_extent=%s"},
82         {Opt_max_inline, "max_inline=%s"},
83         {Opt_alloc_start, "alloc_start=%s"},
84         {Opt_thread_pool, "thread_pool=%d"},
85         {Opt_compress, "compress"},
86         {Opt_ssd, "ssd"},
87         {Opt_noacl, "noacl"},
88         {Opt_notreelog, "notreelog"},
89         {Opt_flushoncommit, "flushoncommit"},
90         {Opt_ratio, "metadata_ratio=%d"},
91         {Opt_err, NULL},
92 };
93
94 u64 btrfs_parse_size(char *str)
95 {
96         u64 res;
97         int mult = 1;
98         char *end;
99         char last;
100
101         res = simple_strtoul(str, &end, 10);
102
103         last = end[0];
104         if (isalpha(last)) {
105                 last = tolower(last);
106                 switch (last) {
107                 case 'g':
108                         mult *= 1024;
109                 case 'm':
110                         mult *= 1024;
111                 case 'k':
112                         mult *= 1024;
113                 }
114                 res = res * mult;
115         }
116         return res;
117 }
118
119 /*
120  * Regular mount options parser.  Everything that is needed only when
121  * reading in a new superblock is parsed here.
122  */
123 int btrfs_parse_options(struct btrfs_root *root, char *options)
124 {
125         struct btrfs_fs_info *info = root->fs_info;
126         substring_t args[MAX_OPT_ARGS];
127         char *p, *num;
128         int intarg;
129
130         if (!options)
131                 return 0;
132
133         /*
134          * strsep changes the string, duplicate it because parse_options
135          * gets called twice
136          */
137         options = kstrdup(options, GFP_NOFS);
138         if (!options)
139                 return -ENOMEM;
140
141
142         while ((p = strsep(&options, ",")) != NULL) {
143                 int token;
144                 if (!*p)
145                         continue;
146
147                 token = match_token(p, tokens, args);
148                 switch (token) {
149                 case Opt_degraded:
150                         printk(KERN_INFO "btrfs: allowing degraded mounts\n");
151                         btrfs_set_opt(info->mount_opt, DEGRADED);
152                         break;
153                 case Opt_subvol:
154                 case Opt_device:
155                         /*
156                          * These are parsed by btrfs_parse_early_options
157                          * and can be happily ignored here.
158                          */
159                         break;
160                 case Opt_nodatasum:
161                         printk(KERN_INFO "btrfs: setting nodatacsum\n");
162                         btrfs_set_opt(info->mount_opt, NODATASUM);
163                         break;
164                 case Opt_nodatacow:
165                         printk(KERN_INFO "btrfs: setting nodatacow\n");
166                         btrfs_set_opt(info->mount_opt, NODATACOW);
167                         btrfs_set_opt(info->mount_opt, NODATASUM);
168                         break;
169                 case Opt_compress:
170                         printk(KERN_INFO "btrfs: use compression\n");
171                         btrfs_set_opt(info->mount_opt, COMPRESS);
172                         break;
173                 case Opt_ssd:
174                         printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
175                         btrfs_set_opt(info->mount_opt, SSD);
176                         break;
177                 case Opt_nobarrier:
178                         printk(KERN_INFO "btrfs: turning off barriers\n");
179                         btrfs_set_opt(info->mount_opt, NOBARRIER);
180                         break;
181                 case Opt_thread_pool:
182                         intarg = 0;
183                         match_int(&args[0], &intarg);
184                         if (intarg) {
185                                 info->thread_pool_size = intarg;
186                                 printk(KERN_INFO "btrfs: thread pool %d\n",
187                                        info->thread_pool_size);
188                         }
189                         break;
190                 case Opt_max_extent:
191                         num = match_strdup(&args[0]);
192                         if (num) {
193                                 info->max_extent = btrfs_parse_size(num);
194                                 kfree(num);
195
196                                 info->max_extent = max_t(u64,
197                                         info->max_extent, root->sectorsize);
198                                 printk(KERN_INFO "btrfs: max_extent at %llu\n",
199                                        (unsigned long long)info->max_extent);
200                         }
201                         break;
202                 case Opt_max_inline:
203                         num = match_strdup(&args[0]);
204                         if (num) {
205                                 info->max_inline = btrfs_parse_size(num);
206                                 kfree(num);
207
208                                 if (info->max_inline) {
209                                         info->max_inline = max_t(u64,
210                                                 info->max_inline,
211                                                 root->sectorsize);
212                                 }
213                                 printk(KERN_INFO "btrfs: max_inline at %llu\n",
214                                         (unsigned long long)info->max_inline);
215                         }
216                         break;
217                 case Opt_alloc_start:
218                         num = match_strdup(&args[0]);
219                         if (num) {
220                                 info->alloc_start = btrfs_parse_size(num);
221                                 kfree(num);
222                                 printk(KERN_INFO
223                                         "btrfs: allocations start at %llu\n",
224                                         (unsigned long long)info->alloc_start);
225                         }
226                         break;
227                 case Opt_noacl:
228                         root->fs_info->sb->s_flags &= ~MS_POSIXACL;
229                         break;
230                 case Opt_notreelog:
231                         printk(KERN_INFO "btrfs: disabling tree log\n");
232                         btrfs_set_opt(info->mount_opt, NOTREELOG);
233                         break;
234                 case Opt_flushoncommit:
235                         printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
236                         btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
237                         break;
238                 case Opt_ratio:
239                         intarg = 0;
240                         match_int(&args[0], &intarg);
241                         if (intarg) {
242                                 info->metadata_ratio = intarg;
243                                 printk(KERN_INFO "btrfs: metadata ratio %d\n",
244                                        info->metadata_ratio);
245                         }
246                         break;
247                 default:
248                         break;
249                 }
250         }
251         kfree(options);
252         return 0;
253 }
254
255 /*
256  * Parse mount options that are required early in the mount process.
257  *
258  * All other options will be parsed on much later in the mount process and
259  * only when we need to allocate a new super block.
260  */
261 static int btrfs_parse_early_options(const char *options, fmode_t flags,
262                 void *holder, char **subvol_name,
263                 struct btrfs_fs_devices **fs_devices)
264 {
265         substring_t args[MAX_OPT_ARGS];
266         char *opts, *p;
267         int error = 0;
268
269         if (!options)
270                 goto out;
271
272         /*
273          * strsep changes the string, duplicate it because parse_options
274          * gets called twice
275          */
276         opts = kstrdup(options, GFP_KERNEL);
277         if (!opts)
278                 return -ENOMEM;
279
280         while ((p = strsep(&opts, ",")) != NULL) {
281                 int token;
282                 if (!*p)
283                         continue;
284
285                 token = match_token(p, tokens, args);
286                 switch (token) {
287                 case Opt_subvol:
288                         *subvol_name = match_strdup(&args[0]);
289                         break;
290                 case Opt_device:
291                         error = btrfs_scan_one_device(match_strdup(&args[0]),
292                                         flags, holder, fs_devices);
293                         if (error)
294                                 goto out_free_opts;
295                         break;
296                 default:
297                         break;
298                 }
299         }
300
301  out_free_opts:
302         kfree(opts);
303  out:
304         /*
305          * If no subvolume name is specified we use the default one.  Allocate
306          * a copy of the string "." here so that code later in the
307          * mount path doesn't care if it's the default volume or another one.
308          */
309         if (!*subvol_name) {
310                 *subvol_name = kstrdup(".", GFP_KERNEL);
311                 if (!*subvol_name)
312                         return -ENOMEM;
313         }
314         return error;
315 }
316
317 static int btrfs_fill_super(struct super_block *sb,
318                             struct btrfs_fs_devices *fs_devices,
319                             void *data, int silent)
320 {
321         struct inode *inode;
322         struct dentry *root_dentry;
323         struct btrfs_super_block *disk_super;
324         struct btrfs_root *tree_root;
325         struct btrfs_inode *bi;
326         int err;
327
328         sb->s_maxbytes = MAX_LFS_FILESIZE;
329         sb->s_magic = BTRFS_SUPER_MAGIC;
330         sb->s_op = &btrfs_super_ops;
331         sb->s_export_op = &btrfs_export_ops;
332         sb->s_xattr = btrfs_xattr_handlers;
333         sb->s_time_gran = 1;
334         sb->s_flags |= MS_POSIXACL;
335
336         tree_root = open_ctree(sb, fs_devices, (char *)data);
337
338         if (IS_ERR(tree_root)) {
339                 printk("btrfs: open_ctree failed\n");
340                 return PTR_ERR(tree_root);
341         }
342         sb->s_fs_info = tree_root;
343         disk_super = &tree_root->fs_info->super_copy;
344         inode = btrfs_iget_locked(sb, BTRFS_FIRST_FREE_OBJECTID,
345                                   tree_root->fs_info->fs_root);
346         bi = BTRFS_I(inode);
347         bi->location.objectid = inode->i_ino;
348         bi->location.offset = 0;
349         bi->root = tree_root->fs_info->fs_root;
350
351         btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
352
353         if (!inode) {
354                 err = -ENOMEM;
355                 goto fail_close;
356         }
357         if (inode->i_state & I_NEW) {
358                 btrfs_read_locked_inode(inode);
359                 unlock_new_inode(inode);
360         }
361
362         root_dentry = d_alloc_root(inode);
363         if (!root_dentry) {
364                 iput(inode);
365                 err = -ENOMEM;
366                 goto fail_close;
367         }
368 #if 0
369         /* this does the super kobj at the same time */
370         err = btrfs_sysfs_add_super(tree_root->fs_info);
371         if (err)
372                 goto fail_close;
373 #endif
374
375         sb->s_root = root_dentry;
376
377         save_mount_options(sb, data);
378         return 0;
379
380 fail_close:
381         close_ctree(tree_root);
382         return err;
383 }
384
385 int btrfs_sync_fs(struct super_block *sb, int wait)
386 {
387         struct btrfs_trans_handle *trans;
388         struct btrfs_root *root = btrfs_sb(sb);
389         int ret;
390
391         if (sb->s_flags & MS_RDONLY)
392                 return 0;
393
394         sb->s_dirt = 0;
395         if (!wait) {
396                 filemap_flush(root->fs_info->btree_inode->i_mapping);
397                 return 0;
398         }
399
400         btrfs_start_delalloc_inodes(root);
401         btrfs_wait_ordered_extents(root, 0);
402
403         trans = btrfs_start_transaction(root, 1);
404         ret = btrfs_commit_transaction(trans, root);
405         sb->s_dirt = 0;
406         return ret;
407 }
408
409 static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
410 {
411         struct btrfs_root *root = btrfs_sb(vfs->mnt_sb);
412         struct btrfs_fs_info *info = root->fs_info;
413
414         if (btrfs_test_opt(root, DEGRADED))
415                 seq_puts(seq, ",degraded");
416         if (btrfs_test_opt(root, NODATASUM))
417                 seq_puts(seq, ",nodatasum");
418         if (btrfs_test_opt(root, NODATACOW))
419                 seq_puts(seq, ",nodatacow");
420         if (btrfs_test_opt(root, NOBARRIER))
421                 seq_puts(seq, ",nobarrier");
422         if (info->max_extent != (u64)-1)
423                 seq_printf(seq, ",max_extent=%llu",
424                            (unsigned long long)info->max_extent);
425         if (info->max_inline != 8192 * 1024)
426                 seq_printf(seq, ",max_inline=%llu",
427                            (unsigned long long)info->max_inline);
428         if (info->alloc_start != 0)
429                 seq_printf(seq, ",alloc_start=%llu",
430                            (unsigned long long)info->alloc_start);
431         if (info->thread_pool_size !=  min_t(unsigned long,
432                                              num_online_cpus() + 2, 8))
433                 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
434         if (btrfs_test_opt(root, COMPRESS))
435                 seq_puts(seq, ",compress");
436         if (btrfs_test_opt(root, SSD))
437                 seq_puts(seq, ",ssd");
438         if (btrfs_test_opt(root, NOTREELOG))
439                 seq_puts(seq, ",notreelog");
440         if (btrfs_test_opt(root, FLUSHONCOMMIT))
441                 seq_puts(seq, ",flushoncommit");
442         if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
443                 seq_puts(seq, ",noacl");
444         return 0;
445 }
446
447 static void btrfs_write_super(struct super_block *sb)
448 {
449         sb->s_dirt = 0;
450 }
451
452 static int btrfs_test_super(struct super_block *s, void *data)
453 {
454         struct btrfs_fs_devices *test_fs_devices = data;
455         struct btrfs_root *root = btrfs_sb(s);
456
457         return root->fs_info->fs_devices == test_fs_devices;
458 }
459
460 /*
461  * Find a superblock for the given device / mount point.
462  *
463  * Note:  This is based on get_sb_bdev from fs/super.c with a few additions
464  *        for multiple device setup.  Make sure to keep it in sync.
465  */
466 static int btrfs_get_sb(struct file_system_type *fs_type, int flags,
467                 const char *dev_name, void *data, struct vfsmount *mnt)
468 {
469         char *subvol_name = NULL;
470         struct block_device *bdev = NULL;
471         struct super_block *s;
472         struct dentry *root;
473         struct btrfs_fs_devices *fs_devices = NULL;
474         fmode_t mode = FMODE_READ;
475         int error = 0;
476
477         if (!(flags & MS_RDONLY))
478                 mode |= FMODE_WRITE;
479
480         error = btrfs_parse_early_options(data, mode, fs_type,
481                                           &subvol_name, &fs_devices);
482         if (error)
483                 return error;
484
485         error = btrfs_scan_one_device(dev_name, mode, fs_type, &fs_devices);
486         if (error)
487                 goto error_free_subvol_name;
488
489         error = btrfs_open_devices(fs_devices, mode, fs_type);
490         if (error)
491                 goto error_free_subvol_name;
492
493         if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
494                 error = -EACCES;
495                 goto error_close_devices;
496         }
497
498         bdev = fs_devices->latest_bdev;
499         s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices);
500         if (IS_ERR(s))
501                 goto error_s;
502
503         if (s->s_root) {
504                 if ((flags ^ s->s_flags) & MS_RDONLY) {
505                         deactivate_locked_super(s);
506                         error = -EBUSY;
507                         goto error_close_devices;
508                 }
509
510                 btrfs_close_devices(fs_devices);
511         } else {
512                 char b[BDEVNAME_SIZE];
513
514                 s->s_flags = flags;
515                 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
516                 error = btrfs_fill_super(s, fs_devices, data,
517                                          flags & MS_SILENT ? 1 : 0);
518                 if (error) {
519                         deactivate_locked_super(s);
520                         goto error_free_subvol_name;
521                 }
522
523                 btrfs_sb(s)->fs_info->bdev_holder = fs_type;
524                 s->s_flags |= MS_ACTIVE;
525         }
526
527         if (!strcmp(subvol_name, "."))
528                 root = dget(s->s_root);
529         else {
530                 mutex_lock(&s->s_root->d_inode->i_mutex);
531                 root = lookup_one_len(subvol_name, s->s_root,
532                                       strlen(subvol_name));
533                 mutex_unlock(&s->s_root->d_inode->i_mutex);
534
535                 if (IS_ERR(root)) {
536                         deactivate_locked_super(s);
537                         error = PTR_ERR(root);
538                         goto error_free_subvol_name;
539                 }
540                 if (!root->d_inode) {
541                         dput(root);
542                         deactivate_locked_super(s);
543                         error = -ENXIO;
544                         goto error_free_subvol_name;
545                 }
546         }
547
548         mnt->mnt_sb = s;
549         mnt->mnt_root = root;
550
551         kfree(subvol_name);
552         return 0;
553
554 error_s:
555         error = PTR_ERR(s);
556 error_close_devices:
557         btrfs_close_devices(fs_devices);
558 error_free_subvol_name:
559         kfree(subvol_name);
560         return error;
561 }
562
563 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
564 {
565         struct btrfs_root *root = btrfs_sb(sb);
566         int ret;
567
568         ret = btrfs_parse_options(root, data);
569         if (ret)
570                 return -EINVAL;
571
572         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
573                 return 0;
574
575         if (*flags & MS_RDONLY) {
576                 sb->s_flags |= MS_RDONLY;
577
578                 ret =  btrfs_commit_super(root);
579                 WARN_ON(ret);
580         } else {
581                 if (root->fs_info->fs_devices->rw_devices == 0)
582                         return -EACCES;
583
584                 if (btrfs_super_log_root(&root->fs_info->super_copy) != 0)
585                         return -EINVAL;
586
587                 ret = btrfs_cleanup_reloc_trees(root);
588                 WARN_ON(ret);
589
590                 ret = btrfs_cleanup_fs_roots(root->fs_info);
591                 WARN_ON(ret);
592
593                 sb->s_flags &= ~MS_RDONLY;
594         }
595
596         return 0;
597 }
598
599 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
600 {
601         struct btrfs_root *root = btrfs_sb(dentry->d_sb);
602         struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
603         int bits = dentry->d_sb->s_blocksize_bits;
604         __be32 *fsid = (__be32 *)root->fs_info->fsid;
605
606         buf->f_namelen = BTRFS_NAME_LEN;
607         buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
608         buf->f_bfree = buf->f_blocks -
609                 (btrfs_super_bytes_used(disk_super) >> bits);
610         buf->f_bavail = buf->f_bfree;
611         buf->f_bsize = dentry->d_sb->s_blocksize;
612         buf->f_type = BTRFS_SUPER_MAGIC;
613
614         /* We treat it as constant endianness (it doesn't matter _which_)
615            because we want the fsid to come out the same whether mounted
616            on a big-endian or little-endian host */
617         buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
618         buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
619         /* Mask in the root object ID too, to disambiguate subvols */
620         buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
621         buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
622
623         return 0;
624 }
625
626 static struct file_system_type btrfs_fs_type = {
627         .owner          = THIS_MODULE,
628         .name           = "btrfs",
629         .get_sb         = btrfs_get_sb,
630         .kill_sb        = kill_anon_super,
631         .fs_flags       = FS_REQUIRES_DEV,
632 };
633
634 /*
635  * used by btrfsctl to scan devices when no FS is mounted
636  */
637 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
638                                 unsigned long arg)
639 {
640         struct btrfs_ioctl_vol_args *vol;
641         struct btrfs_fs_devices *fs_devices;
642         int ret = -ENOTTY;
643
644         if (!capable(CAP_SYS_ADMIN))
645                 return -EPERM;
646
647         vol = memdup_user((void __user *)arg, sizeof(*vol));
648         if (IS_ERR(vol))
649                 return PTR_ERR(vol);
650
651         switch (cmd) {
652         case BTRFS_IOC_SCAN_DEV:
653                 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
654                                             &btrfs_fs_type, &fs_devices);
655                 break;
656         }
657
658         kfree(vol);
659         return ret;
660 }
661
662 static int btrfs_freeze(struct super_block *sb)
663 {
664         struct btrfs_root *root = btrfs_sb(sb);
665         mutex_lock(&root->fs_info->transaction_kthread_mutex);
666         mutex_lock(&root->fs_info->cleaner_mutex);
667         return 0;
668 }
669
670 static int btrfs_unfreeze(struct super_block *sb)
671 {
672         struct btrfs_root *root = btrfs_sb(sb);
673         mutex_unlock(&root->fs_info->cleaner_mutex);
674         mutex_unlock(&root->fs_info->transaction_kthread_mutex);
675         return 0;
676 }
677
678 static struct super_operations btrfs_super_ops = {
679         .delete_inode   = btrfs_delete_inode,
680         .put_super      = btrfs_put_super,
681         .write_super    = btrfs_write_super,
682         .sync_fs        = btrfs_sync_fs,
683         .show_options   = btrfs_show_options,
684         .write_inode    = btrfs_write_inode,
685         .dirty_inode    = btrfs_dirty_inode,
686         .alloc_inode    = btrfs_alloc_inode,
687         .destroy_inode  = btrfs_destroy_inode,
688         .statfs         = btrfs_statfs,
689         .remount_fs     = btrfs_remount,
690         .freeze_fs      = btrfs_freeze,
691         .unfreeze_fs    = btrfs_unfreeze,
692 };
693
694 static const struct file_operations btrfs_ctl_fops = {
695         .unlocked_ioctl  = btrfs_control_ioctl,
696         .compat_ioctl = btrfs_control_ioctl,
697         .owner   = THIS_MODULE,
698 };
699
700 static struct miscdevice btrfs_misc = {
701         .minor          = MISC_DYNAMIC_MINOR,
702         .name           = "btrfs-control",
703         .fops           = &btrfs_ctl_fops
704 };
705
706 static int btrfs_interface_init(void)
707 {
708         return misc_register(&btrfs_misc);
709 }
710
711 static void btrfs_interface_exit(void)
712 {
713         if (misc_deregister(&btrfs_misc) < 0)
714                 printk(KERN_INFO "misc_deregister failed for control device");
715 }
716
717 static int __init init_btrfs_fs(void)
718 {
719         int err;
720
721         err = btrfs_init_sysfs();
722         if (err)
723                 return err;
724
725         err = btrfs_init_cachep();
726         if (err)
727                 goto free_sysfs;
728
729         err = extent_io_init();
730         if (err)
731                 goto free_cachep;
732
733         err = extent_map_init();
734         if (err)
735                 goto free_extent_io;
736
737         err = btrfs_interface_init();
738         if (err)
739                 goto free_extent_map;
740
741         err = register_filesystem(&btrfs_fs_type);
742         if (err)
743                 goto unregister_ioctl;
744
745         printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
746         return 0;
747
748 unregister_ioctl:
749         btrfs_interface_exit();
750 free_extent_map:
751         extent_map_exit();
752 free_extent_io:
753         extent_io_exit();
754 free_cachep:
755         btrfs_destroy_cachep();
756 free_sysfs:
757         btrfs_exit_sysfs();
758         return err;
759 }
760
761 static void __exit exit_btrfs_fs(void)
762 {
763         btrfs_destroy_cachep();
764         extent_map_exit();
765         extent_io_exit();
766         btrfs_interface_exit();
767         unregister_filesystem(&btrfs_fs_type);
768         btrfs_exit_sysfs();
769         btrfs_cleanup_fs_uuids();
770         btrfs_zlib_exit();
771 }
772
773 module_init(init_btrfs_fs)
774 module_exit(exit_btrfs_fs)
775
776 MODULE_LICENSE("GPL");