Btrfs: fix memory leak in btrfs_parse_early_options()
[linux-3.10.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/backing-dev.h>
30 #include <linux/mount.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/parser.h>
37 #include <linux/ctype.h>
38 #include <linux/namei.h>
39 #include <linux/miscdevice.h>
40 #include <linux/magic.h>
41 #include <linux/slab.h>
42 #include <linux/cleancache.h>
43 #include <linux/mnt_namespace.h>
44 #include "compat.h"
45 #include "delayed-inode.h"
46 #include "ctree.h"
47 #include "disk-io.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "ioctl.h"
51 #include "print-tree.h"
52 #include "xattr.h"
53 #include "volumes.h"
54 #include "version.h"
55 #include "export.h"
56 #include "compression.h"
57
58 #define CREATE_TRACE_POINTS
59 #include <trace/events/btrfs.h>
60
61 static const struct super_operations btrfs_super_ops;
62 static struct file_system_type btrfs_fs_type;
63
64 static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno,
65                                       char nbuf[16])
66 {
67         char *errstr = NULL;
68
69         switch (errno) {
70         case -EIO:
71                 errstr = "IO failure";
72                 break;
73         case -ENOMEM:
74                 errstr = "Out of memory";
75                 break;
76         case -EROFS:
77                 errstr = "Readonly filesystem";
78                 break;
79         default:
80                 if (nbuf) {
81                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
82                                 errstr = nbuf;
83                 }
84                 break;
85         }
86
87         return errstr;
88 }
89
90 static void __save_error_info(struct btrfs_fs_info *fs_info)
91 {
92         /*
93          * today we only save the error info into ram.  Long term we'll
94          * also send it down to the disk
95          */
96         fs_info->fs_state = BTRFS_SUPER_FLAG_ERROR;
97 }
98
99 /* NOTE:
100  *      We move write_super stuff at umount in order to avoid deadlock
101  *      for umount hold all lock.
102  */
103 static void save_error_info(struct btrfs_fs_info *fs_info)
104 {
105         __save_error_info(fs_info);
106 }
107
108 /* btrfs handle error by forcing the filesystem readonly */
109 static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
110 {
111         struct super_block *sb = fs_info->sb;
112
113         if (sb->s_flags & MS_RDONLY)
114                 return;
115
116         if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
117                 sb->s_flags |= MS_RDONLY;
118                 printk(KERN_INFO "btrfs is forced readonly\n");
119         }
120 }
121
122 /*
123  * __btrfs_std_error decodes expected errors from the caller and
124  * invokes the approciate error response.
125  */
126 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
127                      unsigned int line, int errno)
128 {
129         struct super_block *sb = fs_info->sb;
130         char nbuf[16];
131         const char *errstr;
132
133         /*
134          * Special case: if the error is EROFS, and we're already
135          * under MS_RDONLY, then it is safe here.
136          */
137         if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
138                 return;
139
140         errstr = btrfs_decode_error(fs_info, errno, nbuf);
141         printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n",
142                 sb->s_id, function, line, errstr);
143         save_error_info(fs_info);
144
145         btrfs_handle_error(fs_info);
146 }
147
148 static void btrfs_put_super(struct super_block *sb)
149 {
150         struct btrfs_root *root = btrfs_sb(sb);
151         int ret;
152
153         ret = close_ctree(root);
154         sb->s_fs_info = NULL;
155
156         (void)ret; /* FIXME: need to fix VFS to return error? */
157 }
158
159 enum {
160         Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
161         Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
162         Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
163         Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
164         Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
165         Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
166         Opt_enospc_debug, Opt_subvolrootid, Opt_defrag,
167         Opt_inode_cache, Opt_no_space_cache, Opt_recovery, Opt_err,
168 };
169
170 static match_table_t tokens = {
171         {Opt_degraded, "degraded"},
172         {Opt_subvol, "subvol=%s"},
173         {Opt_subvolid, "subvolid=%d"},
174         {Opt_device, "device=%s"},
175         {Opt_nodatasum, "nodatasum"},
176         {Opt_nodatacow, "nodatacow"},
177         {Opt_nobarrier, "nobarrier"},
178         {Opt_max_inline, "max_inline=%s"},
179         {Opt_alloc_start, "alloc_start=%s"},
180         {Opt_thread_pool, "thread_pool=%d"},
181         {Opt_compress, "compress"},
182         {Opt_compress_type, "compress=%s"},
183         {Opt_compress_force, "compress-force"},
184         {Opt_compress_force_type, "compress-force=%s"},
185         {Opt_ssd, "ssd"},
186         {Opt_ssd_spread, "ssd_spread"},
187         {Opt_nossd, "nossd"},
188         {Opt_noacl, "noacl"},
189         {Opt_notreelog, "notreelog"},
190         {Opt_flushoncommit, "flushoncommit"},
191         {Opt_ratio, "metadata_ratio=%d"},
192         {Opt_discard, "discard"},
193         {Opt_space_cache, "space_cache"},
194         {Opt_clear_cache, "clear_cache"},
195         {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
196         {Opt_enospc_debug, "enospc_debug"},
197         {Opt_subvolrootid, "subvolrootid=%d"},
198         {Opt_defrag, "autodefrag"},
199         {Opt_inode_cache, "inode_cache"},
200         {Opt_no_space_cache, "no_space_cache"},
201         {Opt_recovery, "recovery"},
202         {Opt_err, NULL},
203 };
204
205 /*
206  * Regular mount options parser.  Everything that is needed only when
207  * reading in a new superblock is parsed here.
208  */
209 int btrfs_parse_options(struct btrfs_root *root, char *options)
210 {
211         struct btrfs_fs_info *info = root->fs_info;
212         substring_t args[MAX_OPT_ARGS];
213         char *p, *num, *orig = NULL;
214         u64 cache_gen;
215         int intarg;
216         int ret = 0;
217         char *compress_type;
218         bool compress_force = false;
219
220         cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
221         if (cache_gen)
222                 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
223
224         if (!options)
225                 goto out;
226
227         /*
228          * strsep changes the string, duplicate it because parse_options
229          * gets called twice
230          */
231         options = kstrdup(options, GFP_NOFS);
232         if (!options)
233                 return -ENOMEM;
234
235         orig = options;
236
237         while ((p = strsep(&options, ",")) != NULL) {
238                 int token;
239                 if (!*p)
240                         continue;
241
242                 token = match_token(p, tokens, args);
243                 switch (token) {
244                 case Opt_degraded:
245                         printk(KERN_INFO "btrfs: allowing degraded mounts\n");
246                         btrfs_set_opt(info->mount_opt, DEGRADED);
247                         break;
248                 case Opt_subvol:
249                 case Opt_subvolid:
250                 case Opt_subvolrootid:
251                 case Opt_device:
252                         /*
253                          * These are parsed by btrfs_parse_early_options
254                          * and can be happily ignored here.
255                          */
256                         break;
257                 case Opt_nodatasum:
258                         printk(KERN_INFO "btrfs: setting nodatasum\n");
259                         btrfs_set_opt(info->mount_opt, NODATASUM);
260                         break;
261                 case Opt_nodatacow:
262                         printk(KERN_INFO "btrfs: setting nodatacow\n");
263                         btrfs_set_opt(info->mount_opt, NODATACOW);
264                         btrfs_set_opt(info->mount_opt, NODATASUM);
265                         break;
266                 case Opt_compress_force:
267                 case Opt_compress_force_type:
268                         compress_force = true;
269                 case Opt_compress:
270                 case Opt_compress_type:
271                         if (token == Opt_compress ||
272                             token == Opt_compress_force ||
273                             strcmp(args[0].from, "zlib") == 0) {
274                                 compress_type = "zlib";
275                                 info->compress_type = BTRFS_COMPRESS_ZLIB;
276                         } else if (strcmp(args[0].from, "lzo") == 0) {
277                                 compress_type = "lzo";
278                                 info->compress_type = BTRFS_COMPRESS_LZO;
279                         } else {
280                                 ret = -EINVAL;
281                                 goto out;
282                         }
283
284                         btrfs_set_opt(info->mount_opt, COMPRESS);
285                         if (compress_force) {
286                                 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
287                                 pr_info("btrfs: force %s compression\n",
288                                         compress_type);
289                         } else
290                                 pr_info("btrfs: use %s compression\n",
291                                         compress_type);
292                         break;
293                 case Opt_ssd:
294                         printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
295                         btrfs_set_opt(info->mount_opt, SSD);
296                         break;
297                 case Opt_ssd_spread:
298                         printk(KERN_INFO "btrfs: use spread ssd "
299                                "allocation scheme\n");
300                         btrfs_set_opt(info->mount_opt, SSD);
301                         btrfs_set_opt(info->mount_opt, SSD_SPREAD);
302                         break;
303                 case Opt_nossd:
304                         printk(KERN_INFO "btrfs: not using ssd allocation "
305                                "scheme\n");
306                         btrfs_set_opt(info->mount_opt, NOSSD);
307                         btrfs_clear_opt(info->mount_opt, SSD);
308                         btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
309                         break;
310                 case Opt_nobarrier:
311                         printk(KERN_INFO "btrfs: turning off barriers\n");
312                         btrfs_set_opt(info->mount_opt, NOBARRIER);
313                         break;
314                 case Opt_thread_pool:
315                         intarg = 0;
316                         match_int(&args[0], &intarg);
317                         if (intarg) {
318                                 info->thread_pool_size = intarg;
319                                 printk(KERN_INFO "btrfs: thread pool %d\n",
320                                        info->thread_pool_size);
321                         }
322                         break;
323                 case Opt_max_inline:
324                         num = match_strdup(&args[0]);
325                         if (num) {
326                                 info->max_inline = memparse(num, NULL);
327                                 kfree(num);
328
329                                 if (info->max_inline) {
330                                         info->max_inline = max_t(u64,
331                                                 info->max_inline,
332                                                 root->sectorsize);
333                                 }
334                                 printk(KERN_INFO "btrfs: max_inline at %llu\n",
335                                         (unsigned long long)info->max_inline);
336                         }
337                         break;
338                 case Opt_alloc_start:
339                         num = match_strdup(&args[0]);
340                         if (num) {
341                                 info->alloc_start = memparse(num, NULL);
342                                 kfree(num);
343                                 printk(KERN_INFO
344                                         "btrfs: allocations start at %llu\n",
345                                         (unsigned long long)info->alloc_start);
346                         }
347                         break;
348                 case Opt_noacl:
349                         root->fs_info->sb->s_flags &= ~MS_POSIXACL;
350                         break;
351                 case Opt_notreelog:
352                         printk(KERN_INFO "btrfs: disabling tree log\n");
353                         btrfs_set_opt(info->mount_opt, NOTREELOG);
354                         break;
355                 case Opt_flushoncommit:
356                         printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
357                         btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
358                         break;
359                 case Opt_ratio:
360                         intarg = 0;
361                         match_int(&args[0], &intarg);
362                         if (intarg) {
363                                 info->metadata_ratio = intarg;
364                                 printk(KERN_INFO "btrfs: metadata ratio %d\n",
365                                        info->metadata_ratio);
366                         }
367                         break;
368                 case Opt_discard:
369                         btrfs_set_opt(info->mount_opt, DISCARD);
370                         break;
371                 case Opt_space_cache:
372                         btrfs_set_opt(info->mount_opt, SPACE_CACHE);
373                         break;
374                 case Opt_no_space_cache:
375                         printk(KERN_INFO "btrfs: disabling disk space caching\n");
376                         btrfs_clear_opt(info->mount_opt, SPACE_CACHE);
377                         break;
378                 case Opt_inode_cache:
379                         printk(KERN_INFO "btrfs: enabling inode map caching\n");
380                         btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
381                         break;
382                 case Opt_clear_cache:
383                         printk(KERN_INFO "btrfs: force clearing of disk cache\n");
384                         btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
385                         break;
386                 case Opt_user_subvol_rm_allowed:
387                         btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
388                         break;
389                 case Opt_enospc_debug:
390                         btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
391                         break;
392                 case Opt_defrag:
393                         printk(KERN_INFO "btrfs: enabling auto defrag");
394                         btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
395                         break;
396                 case Opt_recovery:
397                         printk(KERN_INFO "btrfs: enabling auto recovery");
398                         btrfs_set_opt(info->mount_opt, RECOVERY);
399                         break;
400                 case Opt_err:
401                         printk(KERN_INFO "btrfs: unrecognized mount option "
402                                "'%s'\n", p);
403                         ret = -EINVAL;
404                         goto out;
405                 default:
406                         break;
407                 }
408         }
409 out:
410         if (!ret && btrfs_test_opt(root, SPACE_CACHE))
411                 printk(KERN_INFO "btrfs: disk space caching is enabled\n");
412         kfree(orig);
413         return ret;
414 }
415
416 /*
417  * Parse mount options that are required early in the mount process.
418  *
419  * All other options will be parsed on much later in the mount process and
420  * only when we need to allocate a new super block.
421  */
422 static int btrfs_parse_early_options(const char *options, fmode_t flags,
423                 void *holder, char **subvol_name, u64 *subvol_objectid,
424                 u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices)
425 {
426         substring_t args[MAX_OPT_ARGS];
427         char *device_name, *opts, *orig, *p;
428         int error = 0;
429         int intarg;
430
431         if (!options)
432                 return 0;
433
434         /*
435          * strsep changes the string, duplicate it because parse_options
436          * gets called twice
437          */
438         opts = kstrdup(options, GFP_KERNEL);
439         if (!opts)
440                 return -ENOMEM;
441         orig = opts;
442
443         while ((p = strsep(&opts, ",")) != NULL) {
444                 int token;
445                 if (!*p)
446                         continue;
447
448                 token = match_token(p, tokens, args);
449                 switch (token) {
450                 case Opt_subvol:
451                         kfree(*subvol_name);
452                         *subvol_name = match_strdup(&args[0]);
453                         break;
454                 case Opt_subvolid:
455                         intarg = 0;
456                         error = match_int(&args[0], &intarg);
457                         if (!error) {
458                                 /* we want the original fs_tree */
459                                 if (!intarg)
460                                         *subvol_objectid =
461                                                 BTRFS_FS_TREE_OBJECTID;
462                                 else
463                                         *subvol_objectid = intarg;
464                         }
465                         break;
466                 case Opt_subvolrootid:
467                         intarg = 0;
468                         error = match_int(&args[0], &intarg);
469                         if (!error) {
470                                 /* we want the original fs_tree */
471                                 if (!intarg)
472                                         *subvol_rootid =
473                                                 BTRFS_FS_TREE_OBJECTID;
474                                 else
475                                         *subvol_rootid = intarg;
476                         }
477                         break;
478                 case Opt_device:
479                         device_name = match_strdup(&args[0]);
480                         if (!device_name) {
481                                 error = -ENOMEM;
482                                 goto out;
483                         }
484                         error = btrfs_scan_one_device(device_name,
485                                         flags, holder, fs_devices);
486                         kfree(device_name);
487                         if (error)
488                                 goto out;
489                         break;
490                 default:
491                         break;
492                 }
493         }
494
495 out:
496         kfree(orig);
497         return error;
498 }
499
500 static struct dentry *get_default_root(struct super_block *sb,
501                                        u64 subvol_objectid)
502 {
503         struct btrfs_root *root = sb->s_fs_info;
504         struct btrfs_root *new_root;
505         struct btrfs_dir_item *di;
506         struct btrfs_path *path;
507         struct btrfs_key location;
508         struct inode *inode;
509         u64 dir_id;
510         int new = 0;
511
512         /*
513          * We have a specific subvol we want to mount, just setup location and
514          * go look up the root.
515          */
516         if (subvol_objectid) {
517                 location.objectid = subvol_objectid;
518                 location.type = BTRFS_ROOT_ITEM_KEY;
519                 location.offset = (u64)-1;
520                 goto find_root;
521         }
522
523         path = btrfs_alloc_path();
524         if (!path)
525                 return ERR_PTR(-ENOMEM);
526         path->leave_spinning = 1;
527
528         /*
529          * Find the "default" dir item which points to the root item that we
530          * will mount by default if we haven't been given a specific subvolume
531          * to mount.
532          */
533         dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
534         di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
535         if (IS_ERR(di)) {
536                 btrfs_free_path(path);
537                 return ERR_CAST(di);
538         }
539         if (!di) {
540                 /*
541                  * Ok the default dir item isn't there.  This is weird since
542                  * it's always been there, but don't freak out, just try and
543                  * mount to root most subvolume.
544                  */
545                 btrfs_free_path(path);
546                 dir_id = BTRFS_FIRST_FREE_OBJECTID;
547                 new_root = root->fs_info->fs_root;
548                 goto setup_root;
549         }
550
551         btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
552         btrfs_free_path(path);
553
554 find_root:
555         new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
556         if (IS_ERR(new_root))
557                 return ERR_CAST(new_root);
558
559         if (btrfs_root_refs(&new_root->root_item) == 0)
560                 return ERR_PTR(-ENOENT);
561
562         dir_id = btrfs_root_dirid(&new_root->root_item);
563 setup_root:
564         location.objectid = dir_id;
565         location.type = BTRFS_INODE_ITEM_KEY;
566         location.offset = 0;
567
568         inode = btrfs_iget(sb, &location, new_root, &new);
569         if (IS_ERR(inode))
570                 return ERR_CAST(inode);
571
572         /*
573          * If we're just mounting the root most subvol put the inode and return
574          * a reference to the dentry.  We will have already gotten a reference
575          * to the inode in btrfs_fill_super so we're good to go.
576          */
577         if (!new && sb->s_root->d_inode == inode) {
578                 iput(inode);
579                 return dget(sb->s_root);
580         }
581
582         return d_obtain_alias(inode);
583 }
584
585 static int btrfs_fill_super(struct super_block *sb,
586                             struct btrfs_fs_devices *fs_devices,
587                             void *data, int silent)
588 {
589         struct inode *inode;
590         struct dentry *root_dentry;
591         struct btrfs_root *tree_root;
592         struct btrfs_key key;
593         int err;
594
595         sb->s_maxbytes = MAX_LFS_FILESIZE;
596         sb->s_magic = BTRFS_SUPER_MAGIC;
597         sb->s_op = &btrfs_super_ops;
598         sb->s_d_op = &btrfs_dentry_operations;
599         sb->s_export_op = &btrfs_export_ops;
600         sb->s_xattr = btrfs_xattr_handlers;
601         sb->s_time_gran = 1;
602 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
603         sb->s_flags |= MS_POSIXACL;
604 #endif
605
606         tree_root = open_ctree(sb, fs_devices, (char *)data);
607
608         if (IS_ERR(tree_root)) {
609                 printk("btrfs: open_ctree failed\n");
610                 return PTR_ERR(tree_root);
611         }
612         sb->s_fs_info = tree_root;
613
614         key.objectid = BTRFS_FIRST_FREE_OBJECTID;
615         key.type = BTRFS_INODE_ITEM_KEY;
616         key.offset = 0;
617         inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root, NULL);
618         if (IS_ERR(inode)) {
619                 err = PTR_ERR(inode);
620                 goto fail_close;
621         }
622
623         root_dentry = d_alloc_root(inode);
624         if (!root_dentry) {
625                 iput(inode);
626                 err = -ENOMEM;
627                 goto fail_close;
628         }
629
630         sb->s_root = root_dentry;
631
632         save_mount_options(sb, data);
633         cleancache_init_fs(sb);
634         return 0;
635
636 fail_close:
637         close_ctree(tree_root);
638         return err;
639 }
640
641 int btrfs_sync_fs(struct super_block *sb, int wait)
642 {
643         struct btrfs_trans_handle *trans;
644         struct btrfs_root *root = btrfs_sb(sb);
645         int ret;
646
647         trace_btrfs_sync_fs(wait);
648
649         if (!wait) {
650                 filemap_flush(root->fs_info->btree_inode->i_mapping);
651                 return 0;
652         }
653
654         btrfs_start_delalloc_inodes(root, 0);
655         btrfs_wait_ordered_extents(root, 0, 0);
656
657         trans = btrfs_start_transaction(root, 0);
658         if (IS_ERR(trans))
659                 return PTR_ERR(trans);
660         ret = btrfs_commit_transaction(trans, root);
661         return ret;
662 }
663
664 static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
665 {
666         struct btrfs_root *root = btrfs_sb(vfs->mnt_sb);
667         struct btrfs_fs_info *info = root->fs_info;
668         char *compress_type;
669
670         if (btrfs_test_opt(root, DEGRADED))
671                 seq_puts(seq, ",degraded");
672         if (btrfs_test_opt(root, NODATASUM))
673                 seq_puts(seq, ",nodatasum");
674         if (btrfs_test_opt(root, NODATACOW))
675                 seq_puts(seq, ",nodatacow");
676         if (btrfs_test_opt(root, NOBARRIER))
677                 seq_puts(seq, ",nobarrier");
678         if (info->max_inline != 8192 * 1024)
679                 seq_printf(seq, ",max_inline=%llu",
680                            (unsigned long long)info->max_inline);
681         if (info->alloc_start != 0)
682                 seq_printf(seq, ",alloc_start=%llu",
683                            (unsigned long long)info->alloc_start);
684         if (info->thread_pool_size !=  min_t(unsigned long,
685                                              num_online_cpus() + 2, 8))
686                 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
687         if (btrfs_test_opt(root, COMPRESS)) {
688                 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
689                         compress_type = "zlib";
690                 else
691                         compress_type = "lzo";
692                 if (btrfs_test_opt(root, FORCE_COMPRESS))
693                         seq_printf(seq, ",compress-force=%s", compress_type);
694                 else
695                         seq_printf(seq, ",compress=%s", compress_type);
696         }
697         if (btrfs_test_opt(root, NOSSD))
698                 seq_puts(seq, ",nossd");
699         if (btrfs_test_opt(root, SSD_SPREAD))
700                 seq_puts(seq, ",ssd_spread");
701         else if (btrfs_test_opt(root, SSD))
702                 seq_puts(seq, ",ssd");
703         if (btrfs_test_opt(root, NOTREELOG))
704                 seq_puts(seq, ",notreelog");
705         if (btrfs_test_opt(root, FLUSHONCOMMIT))
706                 seq_puts(seq, ",flushoncommit");
707         if (btrfs_test_opt(root, DISCARD))
708                 seq_puts(seq, ",discard");
709         if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
710                 seq_puts(seq, ",noacl");
711         if (btrfs_test_opt(root, SPACE_CACHE))
712                 seq_puts(seq, ",space_cache");
713         else
714                 seq_puts(seq, ",no_space_cache");
715         if (btrfs_test_opt(root, CLEAR_CACHE))
716                 seq_puts(seq, ",clear_cache");
717         if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
718                 seq_puts(seq, ",user_subvol_rm_allowed");
719         if (btrfs_test_opt(root, ENOSPC_DEBUG))
720                 seq_puts(seq, ",enospc_debug");
721         if (btrfs_test_opt(root, AUTO_DEFRAG))
722                 seq_puts(seq, ",autodefrag");
723         if (btrfs_test_opt(root, INODE_MAP_CACHE))
724                 seq_puts(seq, ",inode_cache");
725         return 0;
726 }
727
728 static int btrfs_test_super(struct super_block *s, void *data)
729 {
730         struct btrfs_root *test_root = data;
731         struct btrfs_root *root = btrfs_sb(s);
732
733         /*
734          * If this super block is going away, return false as it
735          * can't match as an existing super block.
736          */
737         if (!atomic_read(&s->s_active))
738                 return 0;
739         return root->fs_info->fs_devices == test_root->fs_info->fs_devices;
740 }
741
742 static int btrfs_set_super(struct super_block *s, void *data)
743 {
744         s->s_fs_info = data;
745
746         return set_anon_super(s, data);
747 }
748
749 /*
750  * subvolumes are identified by ino 256
751  */
752 static inline int is_subvolume_inode(struct inode *inode)
753 {
754         if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
755                 return 1;
756         return 0;
757 }
758
759 /*
760  * This will strip out the subvol=%s argument for an argument string and add
761  * subvolid=0 to make sure we get the actual tree root for path walking to the
762  * subvol we want.
763  */
764 static char *setup_root_args(char *args)
765 {
766         unsigned copied = 0;
767         unsigned len = strlen(args) + 2;
768         char *pos;
769         char *ret;
770
771         /*
772          * We need the same args as before, but minus
773          *
774          * subvol=a
775          *
776          * and add
777          *
778          * subvolid=0
779          *
780          * which is a difference of 2 characters, so we allocate strlen(args) +
781          * 2 characters.
782          */
783         ret = kzalloc(len * sizeof(char), GFP_NOFS);
784         if (!ret)
785                 return NULL;
786         pos = strstr(args, "subvol=");
787
788         /* This shouldn't happen, but just in case.. */
789         if (!pos) {
790                 kfree(ret);
791                 return NULL;
792         }
793
794         /*
795          * The subvol=<> arg is not at the front of the string, copy everybody
796          * up to that into ret.
797          */
798         if (pos != args) {
799                 *pos = '\0';
800                 strcpy(ret, args);
801                 copied += strlen(args);
802                 pos++;
803         }
804
805         strncpy(ret + copied, "subvolid=0", len - copied);
806
807         /* Length of subvolid=0 */
808         copied += 10;
809
810         /*
811          * If there is no , after the subvol= option then we know there's no
812          * other options and we can just return.
813          */
814         pos = strchr(pos, ',');
815         if (!pos)
816                 return ret;
817
818         /* Copy the rest of the arguments into our buffer */
819         strncpy(ret + copied, pos, len - copied);
820         copied += strlen(pos);
821
822         return ret;
823 }
824
825 static struct dentry *mount_subvol(const char *subvol_name, int flags,
826                                    const char *device_name, char *data)
827 {
828         struct super_block *s;
829         struct dentry *root;
830         struct vfsmount *mnt;
831         struct mnt_namespace *ns_private;
832         char *newargs;
833         struct path path;
834         int error;
835
836         newargs = setup_root_args(data);
837         if (!newargs)
838                 return ERR_PTR(-ENOMEM);
839         mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
840                              newargs);
841         kfree(newargs);
842         if (IS_ERR(mnt))
843                 return ERR_CAST(mnt);
844
845         ns_private = create_mnt_ns(mnt);
846         if (IS_ERR(ns_private)) {
847                 mntput(mnt);
848                 return ERR_CAST(ns_private);
849         }
850
851         /*
852          * This will trigger the automount of the subvol so we can just
853          * drop the mnt we have here and return the dentry that we
854          * found.
855          */
856         error = vfs_path_lookup(mnt->mnt_root, mnt, subvol_name,
857                                 LOOKUP_FOLLOW, &path);
858         put_mnt_ns(ns_private);
859         if (error)
860                 return ERR_PTR(error);
861
862         if (!is_subvolume_inode(path.dentry->d_inode)) {
863                 path_put(&path);
864                 mntput(mnt);
865                 error = -EINVAL;
866                 printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n",
867                                 subvol_name);
868                 return ERR_PTR(-EINVAL);
869         }
870
871         /* Get a ref to the sb and the dentry we found and return it */
872         s = path.mnt->mnt_sb;
873         atomic_inc(&s->s_active);
874         root = dget(path.dentry);
875         path_put(&path);
876         down_write(&s->s_umount);
877
878         return root;
879 }
880
881 /*
882  * Find a superblock for the given device / mount point.
883  *
884  * Note:  This is based on get_sb_bdev from fs/super.c with a few additions
885  *        for multiple device setup.  Make sure to keep it in sync.
886  */
887 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
888                 const char *device_name, void *data)
889 {
890         struct block_device *bdev = NULL;
891         struct super_block *s;
892         struct dentry *root;
893         struct btrfs_fs_devices *fs_devices = NULL;
894         struct btrfs_root *tree_root = NULL;
895         struct btrfs_fs_info *fs_info = NULL;
896         fmode_t mode = FMODE_READ;
897         char *subvol_name = NULL;
898         u64 subvol_objectid = 0;
899         u64 subvol_rootid = 0;
900         int error = 0;
901
902         if (!(flags & MS_RDONLY))
903                 mode |= FMODE_WRITE;
904
905         error = btrfs_parse_early_options(data, mode, fs_type,
906                                           &subvol_name, &subvol_objectid,
907                                           &subvol_rootid, &fs_devices);
908         if (error)
909                 return ERR_PTR(error);
910
911         if (subvol_name) {
912                 root = mount_subvol(subvol_name, flags, device_name, data);
913                 kfree(subvol_name);
914                 return root;
915         }
916
917         error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
918         if (error)
919                 return ERR_PTR(error);
920
921         error = btrfs_open_devices(fs_devices, mode, fs_type);
922         if (error)
923                 return ERR_PTR(error);
924
925         if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
926                 error = -EACCES;
927                 goto error_close_devices;
928         }
929
930         /*
931          * Setup a dummy root and fs_info for test/set super.  This is because
932          * we don't actually fill this stuff out until open_ctree, but we need
933          * it for searching for existing supers, so this lets us do that and
934          * then open_ctree will properly initialize everything later.
935          */
936         fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
937         if (!fs_info) {
938                 error = -ENOMEM;
939                 goto error_close_devices;
940         }
941         tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
942         if (!tree_root) {
943                 error = -ENOMEM;
944                 goto error_close_devices;
945         }
946         fs_info->tree_root = tree_root;
947         fs_info->fs_devices = fs_devices;
948         tree_root->fs_info = fs_info;
949
950         fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
951         fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
952         if (!fs_info->super_copy || !fs_info->super_for_commit) {
953                 error = -ENOMEM;
954                 goto error_close_devices;
955         }
956
957         bdev = fs_devices->latest_bdev;
958         s = sget(fs_type, btrfs_test_super, btrfs_set_super, tree_root);
959         if (IS_ERR(s)) {
960                 error = PTR_ERR(s);
961                 goto error_close_devices;
962         }
963
964         if (s->s_root) {
965                 if ((flags ^ s->s_flags) & MS_RDONLY) {
966                         deactivate_locked_super(s);
967                         return ERR_PTR(-EBUSY);
968                 }
969
970                 btrfs_close_devices(fs_devices);
971                 free_fs_info(fs_info);
972         } else {
973                 char b[BDEVNAME_SIZE];
974
975                 s->s_flags = flags | MS_NOSEC;
976                 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
977                 btrfs_sb(s)->fs_info->bdev_holder = fs_type;
978                 error = btrfs_fill_super(s, fs_devices, data,
979                                          flags & MS_SILENT ? 1 : 0);
980                 if (error) {
981                         deactivate_locked_super(s);
982                         return ERR_PTR(error);
983                 }
984
985                 s->s_flags |= MS_ACTIVE;
986         }
987
988         root = get_default_root(s, subvol_objectid);
989         if (IS_ERR(root)) {
990                 deactivate_locked_super(s);
991                 return root;
992         }
993
994         return root;
995
996 error_close_devices:
997         btrfs_close_devices(fs_devices);
998         free_fs_info(fs_info);
999         return ERR_PTR(error);
1000 }
1001
1002 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1003 {
1004         struct btrfs_root *root = btrfs_sb(sb);
1005         int ret;
1006
1007         ret = btrfs_parse_options(root, data);
1008         if (ret)
1009                 return -EINVAL;
1010
1011         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1012                 return 0;
1013
1014         if (*flags & MS_RDONLY) {
1015                 sb->s_flags |= MS_RDONLY;
1016
1017                 ret =  btrfs_commit_super(root);
1018                 WARN_ON(ret);
1019         } else {
1020                 if (root->fs_info->fs_devices->rw_devices == 0)
1021                         return -EACCES;
1022
1023                 if (btrfs_super_log_root(root->fs_info->super_copy) != 0)
1024                         return -EINVAL;
1025
1026                 ret = btrfs_cleanup_fs_roots(root->fs_info);
1027                 WARN_ON(ret);
1028
1029                 /* recover relocation */
1030                 ret = btrfs_recover_relocation(root);
1031                 WARN_ON(ret);
1032
1033                 sb->s_flags &= ~MS_RDONLY;
1034         }
1035
1036         return 0;
1037 }
1038
1039 /* Used to sort the devices by max_avail(descending sort) */
1040 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1041                                        const void *dev_info2)
1042 {
1043         if (((struct btrfs_device_info *)dev_info1)->max_avail >
1044             ((struct btrfs_device_info *)dev_info2)->max_avail)
1045                 return -1;
1046         else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1047                  ((struct btrfs_device_info *)dev_info2)->max_avail)
1048                 return 1;
1049         else
1050         return 0;
1051 }
1052
1053 /*
1054  * sort the devices by max_avail, in which max free extent size of each device
1055  * is stored.(Descending Sort)
1056  */
1057 static inline void btrfs_descending_sort_devices(
1058                                         struct btrfs_device_info *devices,
1059                                         size_t nr_devices)
1060 {
1061         sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1062              btrfs_cmp_device_free_bytes, NULL);
1063 }
1064
1065 /*
1066  * The helper to calc the free space on the devices that can be used to store
1067  * file data.
1068  */
1069 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1070 {
1071         struct btrfs_fs_info *fs_info = root->fs_info;
1072         struct btrfs_device_info *devices_info;
1073         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1074         struct btrfs_device *device;
1075         u64 skip_space;
1076         u64 type;
1077         u64 avail_space;
1078         u64 used_space;
1079         u64 min_stripe_size;
1080         int min_stripes = 1;
1081         int i = 0, nr_devices;
1082         int ret;
1083
1084         nr_devices = fs_info->fs_devices->rw_devices;
1085         BUG_ON(!nr_devices);
1086
1087         devices_info = kmalloc(sizeof(*devices_info) * nr_devices,
1088                                GFP_NOFS);
1089         if (!devices_info)
1090                 return -ENOMEM;
1091
1092         /* calc min stripe number for data space alloction */
1093         type = btrfs_get_alloc_profile(root, 1);
1094         if (type & BTRFS_BLOCK_GROUP_RAID0)
1095                 min_stripes = 2;
1096         else if (type & BTRFS_BLOCK_GROUP_RAID1)
1097                 min_stripes = 2;
1098         else if (type & BTRFS_BLOCK_GROUP_RAID10)
1099                 min_stripes = 4;
1100
1101         if (type & BTRFS_BLOCK_GROUP_DUP)
1102                 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1103         else
1104                 min_stripe_size = BTRFS_STRIPE_LEN;
1105
1106         list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
1107                 if (!device->in_fs_metadata)
1108                         continue;
1109
1110                 avail_space = device->total_bytes - device->bytes_used;
1111
1112                 /* align with stripe_len */
1113                 do_div(avail_space, BTRFS_STRIPE_LEN);
1114                 avail_space *= BTRFS_STRIPE_LEN;
1115
1116                 /*
1117                  * In order to avoid overwritting the superblock on the drive,
1118                  * btrfs starts at an offset of at least 1MB when doing chunk
1119                  * allocation.
1120                  */
1121                 skip_space = 1024 * 1024;
1122
1123                 /* user can set the offset in fs_info->alloc_start. */
1124                 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1125                     device->total_bytes)
1126                         skip_space = max(fs_info->alloc_start, skip_space);
1127
1128                 /*
1129                  * btrfs can not use the free space in [0, skip_space - 1],
1130                  * we must subtract it from the total. In order to implement
1131                  * it, we account the used space in this range first.
1132                  */
1133                 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1134                                                      &used_space);
1135                 if (ret) {
1136                         kfree(devices_info);
1137                         return ret;
1138                 }
1139
1140                 /* calc the free space in [0, skip_space - 1] */
1141                 skip_space -= used_space;
1142
1143                 /*
1144                  * we can use the free space in [0, skip_space - 1], subtract
1145                  * it from the total.
1146                  */
1147                 if (avail_space && avail_space >= skip_space)
1148                         avail_space -= skip_space;
1149                 else
1150                         avail_space = 0;
1151
1152                 if (avail_space < min_stripe_size)
1153                         continue;
1154
1155                 devices_info[i].dev = device;
1156                 devices_info[i].max_avail = avail_space;
1157
1158                 i++;
1159         }
1160
1161         nr_devices = i;
1162
1163         btrfs_descending_sort_devices(devices_info, nr_devices);
1164
1165         i = nr_devices - 1;
1166         avail_space = 0;
1167         while (nr_devices >= min_stripes) {
1168                 if (devices_info[i].max_avail >= min_stripe_size) {
1169                         int j;
1170                         u64 alloc_size;
1171
1172                         avail_space += devices_info[i].max_avail * min_stripes;
1173                         alloc_size = devices_info[i].max_avail;
1174                         for (j = i + 1 - min_stripes; j <= i; j++)
1175                                 devices_info[j].max_avail -= alloc_size;
1176                 }
1177                 i--;
1178                 nr_devices--;
1179         }
1180
1181         kfree(devices_info);
1182         *free_bytes = avail_space;
1183         return 0;
1184 }
1185
1186 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1187 {
1188         struct btrfs_root *root = btrfs_sb(dentry->d_sb);
1189         struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1190         struct list_head *head = &root->fs_info->space_info;
1191         struct btrfs_space_info *found;
1192         u64 total_used = 0;
1193         u64 total_free_data = 0;
1194         int bits = dentry->d_sb->s_blocksize_bits;
1195         __be32 *fsid = (__be32 *)root->fs_info->fsid;
1196         int ret;
1197
1198         /* holding chunk_muext to avoid allocating new chunks */
1199         mutex_lock(&root->fs_info->chunk_mutex);
1200         rcu_read_lock();
1201         list_for_each_entry_rcu(found, head, list) {
1202                 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1203                         total_free_data += found->disk_total - found->disk_used;
1204                         total_free_data -=
1205                                 btrfs_account_ro_block_groups_free_space(found);
1206                 }
1207
1208                 total_used += found->disk_used;
1209         }
1210         rcu_read_unlock();
1211
1212         buf->f_namelen = BTRFS_NAME_LEN;
1213         buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1214         buf->f_bfree = buf->f_blocks - (total_used >> bits);
1215         buf->f_bsize = dentry->d_sb->s_blocksize;
1216         buf->f_type = BTRFS_SUPER_MAGIC;
1217         buf->f_bavail = total_free_data;
1218         ret = btrfs_calc_avail_data_space(root, &total_free_data);
1219         if (ret) {
1220                 mutex_unlock(&root->fs_info->chunk_mutex);
1221                 return ret;
1222         }
1223         buf->f_bavail += total_free_data;
1224         buf->f_bavail = buf->f_bavail >> bits;
1225         mutex_unlock(&root->fs_info->chunk_mutex);
1226
1227         /* We treat it as constant endianness (it doesn't matter _which_)
1228            because we want the fsid to come out the same whether mounted
1229            on a big-endian or little-endian host */
1230         buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1231         buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1232         /* Mask in the root object ID too, to disambiguate subvols */
1233         buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1234         buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1235
1236         return 0;
1237 }
1238
1239 static struct file_system_type btrfs_fs_type = {
1240         .owner          = THIS_MODULE,
1241         .name           = "btrfs",
1242         .mount          = btrfs_mount,
1243         .kill_sb        = kill_anon_super,
1244         .fs_flags       = FS_REQUIRES_DEV,
1245 };
1246
1247 /*
1248  * used by btrfsctl to scan devices when no FS is mounted
1249  */
1250 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1251                                 unsigned long arg)
1252 {
1253         struct btrfs_ioctl_vol_args *vol;
1254         struct btrfs_fs_devices *fs_devices;
1255         int ret = -ENOTTY;
1256
1257         if (!capable(CAP_SYS_ADMIN))
1258                 return -EPERM;
1259
1260         vol = memdup_user((void __user *)arg, sizeof(*vol));
1261         if (IS_ERR(vol))
1262                 return PTR_ERR(vol);
1263
1264         switch (cmd) {
1265         case BTRFS_IOC_SCAN_DEV:
1266                 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1267                                             &btrfs_fs_type, &fs_devices);
1268                 break;
1269         }
1270
1271         kfree(vol);
1272         return ret;
1273 }
1274
1275 static int btrfs_freeze(struct super_block *sb)
1276 {
1277         struct btrfs_root *root = btrfs_sb(sb);
1278         mutex_lock(&root->fs_info->transaction_kthread_mutex);
1279         mutex_lock(&root->fs_info->cleaner_mutex);
1280         return 0;
1281 }
1282
1283 static int btrfs_unfreeze(struct super_block *sb)
1284 {
1285         struct btrfs_root *root = btrfs_sb(sb);
1286         mutex_unlock(&root->fs_info->cleaner_mutex);
1287         mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1288         return 0;
1289 }
1290
1291 static const struct super_operations btrfs_super_ops = {
1292         .drop_inode     = btrfs_drop_inode,
1293         .evict_inode    = btrfs_evict_inode,
1294         .put_super      = btrfs_put_super,
1295         .sync_fs        = btrfs_sync_fs,
1296         .show_options   = btrfs_show_options,
1297         .write_inode    = btrfs_write_inode,
1298         .dirty_inode    = btrfs_dirty_inode,
1299         .alloc_inode    = btrfs_alloc_inode,
1300         .destroy_inode  = btrfs_destroy_inode,
1301         .statfs         = btrfs_statfs,
1302         .remount_fs     = btrfs_remount,
1303         .freeze_fs      = btrfs_freeze,
1304         .unfreeze_fs    = btrfs_unfreeze,
1305 };
1306
1307 static const struct file_operations btrfs_ctl_fops = {
1308         .unlocked_ioctl  = btrfs_control_ioctl,
1309         .compat_ioctl = btrfs_control_ioctl,
1310         .owner   = THIS_MODULE,
1311         .llseek = noop_llseek,
1312 };
1313
1314 static struct miscdevice btrfs_misc = {
1315         .minor          = BTRFS_MINOR,
1316         .name           = "btrfs-control",
1317         .fops           = &btrfs_ctl_fops
1318 };
1319
1320 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1321 MODULE_ALIAS("devname:btrfs-control");
1322
1323 static int btrfs_interface_init(void)
1324 {
1325         return misc_register(&btrfs_misc);
1326 }
1327
1328 static void btrfs_interface_exit(void)
1329 {
1330         if (misc_deregister(&btrfs_misc) < 0)
1331                 printk(KERN_INFO "misc_deregister failed for control device");
1332 }
1333
1334 static int __init init_btrfs_fs(void)
1335 {
1336         int err;
1337
1338         err = btrfs_init_sysfs();
1339         if (err)
1340                 return err;
1341
1342         err = btrfs_init_compress();
1343         if (err)
1344                 goto free_sysfs;
1345
1346         err = btrfs_init_cachep();
1347         if (err)
1348                 goto free_compress;
1349
1350         err = extent_io_init();
1351         if (err)
1352                 goto free_cachep;
1353
1354         err = extent_map_init();
1355         if (err)
1356                 goto free_extent_io;
1357
1358         err = btrfs_delayed_inode_init();
1359         if (err)
1360                 goto free_extent_map;
1361
1362         err = btrfs_interface_init();
1363         if (err)
1364                 goto free_delayed_inode;
1365
1366         err = register_filesystem(&btrfs_fs_type);
1367         if (err)
1368                 goto unregister_ioctl;
1369
1370         printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
1371         return 0;
1372
1373 unregister_ioctl:
1374         btrfs_interface_exit();
1375 free_delayed_inode:
1376         btrfs_delayed_inode_exit();
1377 free_extent_map:
1378         extent_map_exit();
1379 free_extent_io:
1380         extent_io_exit();
1381 free_cachep:
1382         btrfs_destroy_cachep();
1383 free_compress:
1384         btrfs_exit_compress();
1385 free_sysfs:
1386         btrfs_exit_sysfs();
1387         return err;
1388 }
1389
1390 static void __exit exit_btrfs_fs(void)
1391 {
1392         btrfs_destroy_cachep();
1393         btrfs_delayed_inode_exit();
1394         extent_map_exit();
1395         extent_io_exit();
1396         btrfs_interface_exit();
1397         unregister_filesystem(&btrfs_fs_type);
1398         btrfs_exit_sysfs();
1399         btrfs_cleanup_fs_uuids();
1400         btrfs_exit_compress();
1401 }
1402
1403 module_init(init_btrfs_fs)
1404 module_exit(exit_btrfs_fs)
1405
1406 MODULE_LICENSE("GPL");