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