switch open-coded instances of d_make_root() to new helper
[linux-2.6.git] / fs / btrfs / super.c
1 /*
2  * Copyright (C) 2007 Oracle.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public
6  * License v2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public
14  * License along with this program; if not, write to the
15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16  * Boston, MA 021110-1307, USA.
17  */
18
19 #include <linux/blkdev.h>
20 #include <linux/module.h>
21 #include <linux/buffer_head.h>
22 #include <linux/fs.h>
23 #include <linux/pagemap.h>
24 #include <linux/highmem.h>
25 #include <linux/time.h>
26 #include <linux/init.h>
27 #include <linux/seq_file.h>
28 #include <linux/string.h>
29 #include <linux/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/ratelimit.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         (void)close_ctree(btrfs_sb(sb)->tree_root);
151         /* FIXME: need to fix VFS to return error? */
152         /* AV: return it _where_?  ->put_super() can be triggered by any number
153          * of async events, up to and including delivery of SIGKILL to the
154          * last process that kept it busy.  Or segfault in the aforementioned
155          * process...  Whom would you report that to?
156          */
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, Opt_inode_cache,
167         Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
168         Opt_check_integrity, Opt_check_integrity_including_extent_data,
169         Opt_check_integrity_print_mask,
170         Opt_err,
171 };
172
173 static match_table_t tokens = {
174         {Opt_degraded, "degraded"},
175         {Opt_subvol, "subvol=%s"},
176         {Opt_subvolid, "subvolid=%d"},
177         {Opt_device, "device=%s"},
178         {Opt_nodatasum, "nodatasum"},
179         {Opt_nodatacow, "nodatacow"},
180         {Opt_nobarrier, "nobarrier"},
181         {Opt_max_inline, "max_inline=%s"},
182         {Opt_alloc_start, "alloc_start=%s"},
183         {Opt_thread_pool, "thread_pool=%d"},
184         {Opt_compress, "compress"},
185         {Opt_compress_type, "compress=%s"},
186         {Opt_compress_force, "compress-force"},
187         {Opt_compress_force_type, "compress-force=%s"},
188         {Opt_ssd, "ssd"},
189         {Opt_ssd_spread, "ssd_spread"},
190         {Opt_nossd, "nossd"},
191         {Opt_noacl, "noacl"},
192         {Opt_notreelog, "notreelog"},
193         {Opt_flushoncommit, "flushoncommit"},
194         {Opt_ratio, "metadata_ratio=%d"},
195         {Opt_discard, "discard"},
196         {Opt_space_cache, "space_cache"},
197         {Opt_clear_cache, "clear_cache"},
198         {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
199         {Opt_enospc_debug, "enospc_debug"},
200         {Opt_subvolrootid, "subvolrootid=%d"},
201         {Opt_defrag, "autodefrag"},
202         {Opt_inode_cache, "inode_cache"},
203         {Opt_no_space_cache, "nospace_cache"},
204         {Opt_recovery, "recovery"},
205         {Opt_skip_balance, "skip_balance"},
206         {Opt_check_integrity, "check_int"},
207         {Opt_check_integrity_including_extent_data, "check_int_data"},
208         {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
209         {Opt_err, NULL},
210 };
211
212 /*
213  * Regular mount options parser.  Everything that is needed only when
214  * reading in a new superblock is parsed here.
215  */
216 int btrfs_parse_options(struct btrfs_root *root, char *options)
217 {
218         struct btrfs_fs_info *info = root->fs_info;
219         substring_t args[MAX_OPT_ARGS];
220         char *p, *num, *orig = NULL;
221         u64 cache_gen;
222         int intarg;
223         int ret = 0;
224         char *compress_type;
225         bool compress_force = false;
226
227         cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
228         if (cache_gen)
229                 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
230
231         if (!options)
232                 goto out;
233
234         /*
235          * strsep changes the string, duplicate it because parse_options
236          * gets called twice
237          */
238         options = kstrdup(options, GFP_NOFS);
239         if (!options)
240                 return -ENOMEM;
241
242         orig = options;
243
244         while ((p = strsep(&options, ",")) != NULL) {
245                 int token;
246                 if (!*p)
247                         continue;
248
249                 token = match_token(p, tokens, args);
250                 switch (token) {
251                 case Opt_degraded:
252                         printk(KERN_INFO "btrfs: allowing degraded mounts\n");
253                         btrfs_set_opt(info->mount_opt, DEGRADED);
254                         break;
255                 case Opt_subvol:
256                 case Opt_subvolid:
257                 case Opt_subvolrootid:
258                 case Opt_device:
259                         /*
260                          * These are parsed by btrfs_parse_early_options
261                          * and can be happily ignored here.
262                          */
263                         break;
264                 case Opt_nodatasum:
265                         printk(KERN_INFO "btrfs: setting nodatasum\n");
266                         btrfs_set_opt(info->mount_opt, NODATASUM);
267                         break;
268                 case Opt_nodatacow:
269                         printk(KERN_INFO "btrfs: setting nodatacow\n");
270                         btrfs_set_opt(info->mount_opt, NODATACOW);
271                         btrfs_set_opt(info->mount_opt, NODATASUM);
272                         break;
273                 case Opt_compress_force:
274                 case Opt_compress_force_type:
275                         compress_force = true;
276                 case Opt_compress:
277                 case Opt_compress_type:
278                         if (token == Opt_compress ||
279                             token == Opt_compress_force ||
280                             strcmp(args[0].from, "zlib") == 0) {
281                                 compress_type = "zlib";
282                                 info->compress_type = BTRFS_COMPRESS_ZLIB;
283                         } else if (strcmp(args[0].from, "lzo") == 0) {
284                                 compress_type = "lzo";
285                                 info->compress_type = BTRFS_COMPRESS_LZO;
286                         } else {
287                                 ret = -EINVAL;
288                                 goto out;
289                         }
290
291                         btrfs_set_opt(info->mount_opt, COMPRESS);
292                         if (compress_force) {
293                                 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
294                                 pr_info("btrfs: force %s compression\n",
295                                         compress_type);
296                         } else
297                                 pr_info("btrfs: use %s compression\n",
298                                         compress_type);
299                         break;
300                 case Opt_ssd:
301                         printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
302                         btrfs_set_opt(info->mount_opt, SSD);
303                         break;
304                 case Opt_ssd_spread:
305                         printk(KERN_INFO "btrfs: use spread ssd "
306                                "allocation scheme\n");
307                         btrfs_set_opt(info->mount_opt, SSD);
308                         btrfs_set_opt(info->mount_opt, SSD_SPREAD);
309                         break;
310                 case Opt_nossd:
311                         printk(KERN_INFO "btrfs: not using ssd allocation "
312                                "scheme\n");
313                         btrfs_set_opt(info->mount_opt, NOSSD);
314                         btrfs_clear_opt(info->mount_opt, SSD);
315                         btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
316                         break;
317                 case Opt_nobarrier:
318                         printk(KERN_INFO "btrfs: turning off barriers\n");
319                         btrfs_set_opt(info->mount_opt, NOBARRIER);
320                         break;
321                 case Opt_thread_pool:
322                         intarg = 0;
323                         match_int(&args[0], &intarg);
324                         if (intarg) {
325                                 info->thread_pool_size = intarg;
326                                 printk(KERN_INFO "btrfs: thread pool %d\n",
327                                        info->thread_pool_size);
328                         }
329                         break;
330                 case Opt_max_inline:
331                         num = match_strdup(&args[0]);
332                         if (num) {
333                                 info->max_inline = memparse(num, NULL);
334                                 kfree(num);
335
336                                 if (info->max_inline) {
337                                         info->max_inline = max_t(u64,
338                                                 info->max_inline,
339                                                 root->sectorsize);
340                                 }
341                                 printk(KERN_INFO "btrfs: max_inline at %llu\n",
342                                         (unsigned long long)info->max_inline);
343                         }
344                         break;
345                 case Opt_alloc_start:
346                         num = match_strdup(&args[0]);
347                         if (num) {
348                                 info->alloc_start = memparse(num, NULL);
349                                 kfree(num);
350                                 printk(KERN_INFO
351                                         "btrfs: allocations start at %llu\n",
352                                         (unsigned long long)info->alloc_start);
353                         }
354                         break;
355                 case Opt_noacl:
356                         root->fs_info->sb->s_flags &= ~MS_POSIXACL;
357                         break;
358                 case Opt_notreelog:
359                         printk(KERN_INFO "btrfs: disabling tree log\n");
360                         btrfs_set_opt(info->mount_opt, NOTREELOG);
361                         break;
362                 case Opt_flushoncommit:
363                         printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
364                         btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
365                         break;
366                 case Opt_ratio:
367                         intarg = 0;
368                         match_int(&args[0], &intarg);
369                         if (intarg) {
370                                 info->metadata_ratio = intarg;
371                                 printk(KERN_INFO "btrfs: metadata ratio %d\n",
372                                        info->metadata_ratio);
373                         }
374                         break;
375                 case Opt_discard:
376                         btrfs_set_opt(info->mount_opt, DISCARD);
377                         break;
378                 case Opt_space_cache:
379                         btrfs_set_opt(info->mount_opt, SPACE_CACHE);
380                         break;
381                 case Opt_no_space_cache:
382                         printk(KERN_INFO "btrfs: disabling disk space caching\n");
383                         btrfs_clear_opt(info->mount_opt, SPACE_CACHE);
384                         break;
385                 case Opt_inode_cache:
386                         printk(KERN_INFO "btrfs: enabling inode map caching\n");
387                         btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
388                         break;
389                 case Opt_clear_cache:
390                         printk(KERN_INFO "btrfs: force clearing of disk cache\n");
391                         btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
392                         break;
393                 case Opt_user_subvol_rm_allowed:
394                         btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
395                         break;
396                 case Opt_enospc_debug:
397                         btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
398                         break;
399                 case Opt_defrag:
400                         printk(KERN_INFO "btrfs: enabling auto defrag");
401                         btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
402                         break;
403                 case Opt_recovery:
404                         printk(KERN_INFO "btrfs: enabling auto recovery");
405                         btrfs_set_opt(info->mount_opt, RECOVERY);
406                         break;
407                 case Opt_skip_balance:
408                         btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
409                         break;
410 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
411                 case Opt_check_integrity_including_extent_data:
412                         printk(KERN_INFO "btrfs: enabling check integrity"
413                                " including extent data\n");
414                         btrfs_set_opt(info->mount_opt,
415                                       CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
416                         btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
417                         break;
418                 case Opt_check_integrity:
419                         printk(KERN_INFO "btrfs: enabling check integrity\n");
420                         btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
421                         break;
422                 case Opt_check_integrity_print_mask:
423                         intarg = 0;
424                         match_int(&args[0], &intarg);
425                         if (intarg) {
426                                 info->check_integrity_print_mask = intarg;
427                                 printk(KERN_INFO "btrfs:"
428                                        " check_integrity_print_mask 0x%x\n",
429                                        info->check_integrity_print_mask);
430                         }
431                         break;
432 #else
433                 case Opt_check_integrity_including_extent_data:
434                 case Opt_check_integrity:
435                 case Opt_check_integrity_print_mask:
436                         printk(KERN_ERR "btrfs: support for check_integrity*"
437                                " not compiled in!\n");
438                         ret = -EINVAL;
439                         goto out;
440 #endif
441                 case Opt_err:
442                         printk(KERN_INFO "btrfs: unrecognized mount option "
443                                "'%s'\n", p);
444                         ret = -EINVAL;
445                         goto out;
446                 default:
447                         break;
448                 }
449         }
450 out:
451         if (!ret && btrfs_test_opt(root, SPACE_CACHE))
452                 printk(KERN_INFO "btrfs: disk space caching is enabled\n");
453         kfree(orig);
454         return ret;
455 }
456
457 /*
458  * Parse mount options that are required early in the mount process.
459  *
460  * All other options will be parsed on much later in the mount process and
461  * only when we need to allocate a new super block.
462  */
463 static int btrfs_parse_early_options(const char *options, fmode_t flags,
464                 void *holder, char **subvol_name, u64 *subvol_objectid,
465                 u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices)
466 {
467         substring_t args[MAX_OPT_ARGS];
468         char *device_name, *opts, *orig, *p;
469         int error = 0;
470         int intarg;
471
472         if (!options)
473                 return 0;
474
475         /*
476          * strsep changes the string, duplicate it because parse_options
477          * gets called twice
478          */
479         opts = kstrdup(options, GFP_KERNEL);
480         if (!opts)
481                 return -ENOMEM;
482         orig = opts;
483
484         while ((p = strsep(&opts, ",")) != NULL) {
485                 int token;
486                 if (!*p)
487                         continue;
488
489                 token = match_token(p, tokens, args);
490                 switch (token) {
491                 case Opt_subvol:
492                         kfree(*subvol_name);
493                         *subvol_name = match_strdup(&args[0]);
494                         break;
495                 case Opt_subvolid:
496                         intarg = 0;
497                         error = match_int(&args[0], &intarg);
498                         if (!error) {
499                                 /* we want the original fs_tree */
500                                 if (!intarg)
501                                         *subvol_objectid =
502                                                 BTRFS_FS_TREE_OBJECTID;
503                                 else
504                                         *subvol_objectid = intarg;
505                         }
506                         break;
507                 case Opt_subvolrootid:
508                         intarg = 0;
509                         error = match_int(&args[0], &intarg);
510                         if (!error) {
511                                 /* we want the original fs_tree */
512                                 if (!intarg)
513                                         *subvol_rootid =
514                                                 BTRFS_FS_TREE_OBJECTID;
515                                 else
516                                         *subvol_rootid = intarg;
517                         }
518                         break;
519                 case Opt_device:
520                         device_name = match_strdup(&args[0]);
521                         if (!device_name) {
522                                 error = -ENOMEM;
523                                 goto out;
524                         }
525                         error = btrfs_scan_one_device(device_name,
526                                         flags, holder, fs_devices);
527                         kfree(device_name);
528                         if (error)
529                                 goto out;
530                         break;
531                 default:
532                         break;
533                 }
534         }
535
536 out:
537         kfree(orig);
538         return error;
539 }
540
541 static struct dentry *get_default_root(struct super_block *sb,
542                                        u64 subvol_objectid)
543 {
544         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
545         struct btrfs_root *root = fs_info->tree_root;
546         struct btrfs_root *new_root;
547         struct btrfs_dir_item *di;
548         struct btrfs_path *path;
549         struct btrfs_key location;
550         struct inode *inode;
551         u64 dir_id;
552         int new = 0;
553
554         /*
555          * We have a specific subvol we want to mount, just setup location and
556          * go look up the root.
557          */
558         if (subvol_objectid) {
559                 location.objectid = subvol_objectid;
560                 location.type = BTRFS_ROOT_ITEM_KEY;
561                 location.offset = (u64)-1;
562                 goto find_root;
563         }
564
565         path = btrfs_alloc_path();
566         if (!path)
567                 return ERR_PTR(-ENOMEM);
568         path->leave_spinning = 1;
569
570         /*
571          * Find the "default" dir item which points to the root item that we
572          * will mount by default if we haven't been given a specific subvolume
573          * to mount.
574          */
575         dir_id = btrfs_super_root_dir(fs_info->super_copy);
576         di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
577         if (IS_ERR(di)) {
578                 btrfs_free_path(path);
579                 return ERR_CAST(di);
580         }
581         if (!di) {
582                 /*
583                  * Ok the default dir item isn't there.  This is weird since
584                  * it's always been there, but don't freak out, just try and
585                  * mount to root most subvolume.
586                  */
587                 btrfs_free_path(path);
588                 dir_id = BTRFS_FIRST_FREE_OBJECTID;
589                 new_root = fs_info->fs_root;
590                 goto setup_root;
591         }
592
593         btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
594         btrfs_free_path(path);
595
596 find_root:
597         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
598         if (IS_ERR(new_root))
599                 return ERR_CAST(new_root);
600
601         if (btrfs_root_refs(&new_root->root_item) == 0)
602                 return ERR_PTR(-ENOENT);
603
604         dir_id = btrfs_root_dirid(&new_root->root_item);
605 setup_root:
606         location.objectid = dir_id;
607         location.type = BTRFS_INODE_ITEM_KEY;
608         location.offset = 0;
609
610         inode = btrfs_iget(sb, &location, new_root, &new);
611         if (IS_ERR(inode))
612                 return ERR_CAST(inode);
613
614         /*
615          * If we're just mounting the root most subvol put the inode and return
616          * a reference to the dentry.  We will have already gotten a reference
617          * to the inode in btrfs_fill_super so we're good to go.
618          */
619         if (!new && sb->s_root->d_inode == inode) {
620                 iput(inode);
621                 return dget(sb->s_root);
622         }
623
624         return d_obtain_alias(inode);
625 }
626
627 static int btrfs_fill_super(struct super_block *sb,
628                             struct btrfs_fs_devices *fs_devices,
629                             void *data, int silent)
630 {
631         struct inode *inode;
632         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
633         struct btrfs_key key;
634         int err;
635
636         sb->s_maxbytes = MAX_LFS_FILESIZE;
637         sb->s_magic = BTRFS_SUPER_MAGIC;
638         sb->s_op = &btrfs_super_ops;
639         sb->s_d_op = &btrfs_dentry_operations;
640         sb->s_export_op = &btrfs_export_ops;
641         sb->s_xattr = btrfs_xattr_handlers;
642         sb->s_time_gran = 1;
643 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
644         sb->s_flags |= MS_POSIXACL;
645 #endif
646
647         err = open_ctree(sb, fs_devices, (char *)data);
648         if (err) {
649                 printk("btrfs: open_ctree failed\n");
650                 return err;
651         }
652
653         key.objectid = BTRFS_FIRST_FREE_OBJECTID;
654         key.type = BTRFS_INODE_ITEM_KEY;
655         key.offset = 0;
656         inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
657         if (IS_ERR(inode)) {
658                 err = PTR_ERR(inode);
659                 goto fail_close;
660         }
661
662         sb->s_root = d_make_root(inode);
663         if (!sb->s_root) {
664                 err = -ENOMEM;
665                 goto fail_close;
666         }
667
668         save_mount_options(sb, data);
669         cleancache_init_fs(sb);
670         sb->s_flags |= MS_ACTIVE;
671         return 0;
672
673 fail_close:
674         close_ctree(fs_info->tree_root);
675         return err;
676 }
677
678 int btrfs_sync_fs(struct super_block *sb, int wait)
679 {
680         struct btrfs_trans_handle *trans;
681         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
682         struct btrfs_root *root = fs_info->tree_root;
683         int ret;
684
685         trace_btrfs_sync_fs(wait);
686
687         if (!wait) {
688                 filemap_flush(fs_info->btree_inode->i_mapping);
689                 return 0;
690         }
691
692         btrfs_start_delalloc_inodes(root, 0);
693         btrfs_wait_ordered_extents(root, 0, 0);
694
695         trans = btrfs_start_transaction(root, 0);
696         if (IS_ERR(trans))
697                 return PTR_ERR(trans);
698         ret = btrfs_commit_transaction(trans, root);
699         return ret;
700 }
701
702 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
703 {
704         struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
705         struct btrfs_root *root = info->tree_root;
706         char *compress_type;
707
708         if (btrfs_test_opt(root, DEGRADED))
709                 seq_puts(seq, ",degraded");
710         if (btrfs_test_opt(root, NODATASUM))
711                 seq_puts(seq, ",nodatasum");
712         if (btrfs_test_opt(root, NODATACOW))
713                 seq_puts(seq, ",nodatacow");
714         if (btrfs_test_opt(root, NOBARRIER))
715                 seq_puts(seq, ",nobarrier");
716         if (info->max_inline != 8192 * 1024)
717                 seq_printf(seq, ",max_inline=%llu",
718                            (unsigned long long)info->max_inline);
719         if (info->alloc_start != 0)
720                 seq_printf(seq, ",alloc_start=%llu",
721                            (unsigned long long)info->alloc_start);
722         if (info->thread_pool_size !=  min_t(unsigned long,
723                                              num_online_cpus() + 2, 8))
724                 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
725         if (btrfs_test_opt(root, COMPRESS)) {
726                 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
727                         compress_type = "zlib";
728                 else
729                         compress_type = "lzo";
730                 if (btrfs_test_opt(root, FORCE_COMPRESS))
731                         seq_printf(seq, ",compress-force=%s", compress_type);
732                 else
733                         seq_printf(seq, ",compress=%s", compress_type);
734         }
735         if (btrfs_test_opt(root, NOSSD))
736                 seq_puts(seq, ",nossd");
737         if (btrfs_test_opt(root, SSD_SPREAD))
738                 seq_puts(seq, ",ssd_spread");
739         else if (btrfs_test_opt(root, SSD))
740                 seq_puts(seq, ",ssd");
741         if (btrfs_test_opt(root, NOTREELOG))
742                 seq_puts(seq, ",notreelog");
743         if (btrfs_test_opt(root, FLUSHONCOMMIT))
744                 seq_puts(seq, ",flushoncommit");
745         if (btrfs_test_opt(root, DISCARD))
746                 seq_puts(seq, ",discard");
747         if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
748                 seq_puts(seq, ",noacl");
749         if (btrfs_test_opt(root, SPACE_CACHE))
750                 seq_puts(seq, ",space_cache");
751         else
752                 seq_puts(seq, ",nospace_cache");
753         if (btrfs_test_opt(root, CLEAR_CACHE))
754                 seq_puts(seq, ",clear_cache");
755         if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
756                 seq_puts(seq, ",user_subvol_rm_allowed");
757         if (btrfs_test_opt(root, ENOSPC_DEBUG))
758                 seq_puts(seq, ",enospc_debug");
759         if (btrfs_test_opt(root, AUTO_DEFRAG))
760                 seq_puts(seq, ",autodefrag");
761         if (btrfs_test_opt(root, INODE_MAP_CACHE))
762                 seq_puts(seq, ",inode_cache");
763         if (btrfs_test_opt(root, SKIP_BALANCE))
764                 seq_puts(seq, ",skip_balance");
765         return 0;
766 }
767
768 static int btrfs_test_super(struct super_block *s, void *data)
769 {
770         struct btrfs_fs_info *p = data;
771         struct btrfs_fs_info *fs_info = btrfs_sb(s);
772
773         return fs_info->fs_devices == p->fs_devices;
774 }
775
776 static int btrfs_set_super(struct super_block *s, void *data)
777 {
778         int err = set_anon_super(s, data);
779         if (!err)
780                 s->s_fs_info = data;
781         return err;
782 }
783
784 /*
785  * subvolumes are identified by ino 256
786  */
787 static inline int is_subvolume_inode(struct inode *inode)
788 {
789         if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
790                 return 1;
791         return 0;
792 }
793
794 /*
795  * This will strip out the subvol=%s argument for an argument string and add
796  * subvolid=0 to make sure we get the actual tree root for path walking to the
797  * subvol we want.
798  */
799 static char *setup_root_args(char *args)
800 {
801         unsigned copied = 0;
802         unsigned len = strlen(args) + 2;
803         char *pos;
804         char *ret;
805
806         /*
807          * We need the same args as before, but minus
808          *
809          * subvol=a
810          *
811          * and add
812          *
813          * subvolid=0
814          *
815          * which is a difference of 2 characters, so we allocate strlen(args) +
816          * 2 characters.
817          */
818         ret = kzalloc(len * sizeof(char), GFP_NOFS);
819         if (!ret)
820                 return NULL;
821         pos = strstr(args, "subvol=");
822
823         /* This shouldn't happen, but just in case.. */
824         if (!pos) {
825                 kfree(ret);
826                 return NULL;
827         }
828
829         /*
830          * The subvol=<> arg is not at the front of the string, copy everybody
831          * up to that into ret.
832          */
833         if (pos != args) {
834                 *pos = '\0';
835                 strcpy(ret, args);
836                 copied += strlen(args);
837                 pos++;
838         }
839
840         strncpy(ret + copied, "subvolid=0", len - copied);
841
842         /* Length of subvolid=0 */
843         copied += 10;
844
845         /*
846          * If there is no , after the subvol= option then we know there's no
847          * other options and we can just return.
848          */
849         pos = strchr(pos, ',');
850         if (!pos)
851                 return ret;
852
853         /* Copy the rest of the arguments into our buffer */
854         strncpy(ret + copied, pos, len - copied);
855         copied += strlen(pos);
856
857         return ret;
858 }
859
860 static struct dentry *mount_subvol(const char *subvol_name, int flags,
861                                    const char *device_name, char *data)
862 {
863         struct dentry *root;
864         struct vfsmount *mnt;
865         char *newargs;
866
867         newargs = setup_root_args(data);
868         if (!newargs)
869                 return ERR_PTR(-ENOMEM);
870         mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
871                              newargs);
872         kfree(newargs);
873         if (IS_ERR(mnt))
874                 return ERR_CAST(mnt);
875
876         root = mount_subtree(mnt, subvol_name);
877
878         if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
879                 struct super_block *s = root->d_sb;
880                 dput(root);
881                 root = ERR_PTR(-EINVAL);
882                 deactivate_locked_super(s);
883                 printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n",
884                                 subvol_name);
885         }
886
887         return root;
888 }
889
890 /*
891  * Find a superblock for the given device / mount point.
892  *
893  * Note:  This is based on get_sb_bdev from fs/super.c with a few additions
894  *        for multiple device setup.  Make sure to keep it in sync.
895  */
896 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
897                 const char *device_name, void *data)
898 {
899         struct block_device *bdev = NULL;
900         struct super_block *s;
901         struct dentry *root;
902         struct btrfs_fs_devices *fs_devices = NULL;
903         struct btrfs_fs_info *fs_info = NULL;
904         fmode_t mode = FMODE_READ;
905         char *subvol_name = NULL;
906         u64 subvol_objectid = 0;
907         u64 subvol_rootid = 0;
908         int error = 0;
909
910         if (!(flags & MS_RDONLY))
911                 mode |= FMODE_WRITE;
912
913         error = btrfs_parse_early_options(data, mode, fs_type,
914                                           &subvol_name, &subvol_objectid,
915                                           &subvol_rootid, &fs_devices);
916         if (error) {
917                 kfree(subvol_name);
918                 return ERR_PTR(error);
919         }
920
921         if (subvol_name) {
922                 root = mount_subvol(subvol_name, flags, device_name, data);
923                 kfree(subvol_name);
924                 return root;
925         }
926
927         error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
928         if (error)
929                 return ERR_PTR(error);
930
931         /*
932          * Setup a dummy root and fs_info for test/set super.  This is because
933          * we don't actually fill this stuff out until open_ctree, but we need
934          * it for searching for existing supers, so this lets us do that and
935          * then open_ctree will properly initialize everything later.
936          */
937         fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
938         if (!fs_info)
939                 return ERR_PTR(-ENOMEM);
940
941         fs_info->fs_devices = fs_devices;
942
943         fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
944         fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
945         if (!fs_info->super_copy || !fs_info->super_for_commit) {
946                 error = -ENOMEM;
947                 goto error_fs_info;
948         }
949
950         error = btrfs_open_devices(fs_devices, mode, fs_type);
951         if (error)
952                 goto error_fs_info;
953
954         if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
955                 error = -EACCES;
956                 goto error_close_devices;
957         }
958
959         bdev = fs_devices->latest_bdev;
960         s = sget(fs_type, btrfs_test_super, btrfs_set_super, fs_info);
961         if (IS_ERR(s)) {
962                 error = PTR_ERR(s);
963                 goto error_close_devices;
964         }
965
966         if (s->s_root) {
967                 btrfs_close_devices(fs_devices);
968                 free_fs_info(fs_info);
969                 if ((flags ^ s->s_flags) & MS_RDONLY)
970                         error = -EBUSY;
971         } else {
972                 char b[BDEVNAME_SIZE];
973
974                 s->s_flags = flags | MS_NOSEC;
975                 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
976                 btrfs_sb(s)->bdev_holder = fs_type;
977                 error = btrfs_fill_super(s, fs_devices, data,
978                                          flags & MS_SILENT ? 1 : 0);
979         }
980
981         root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
982         if (IS_ERR(root))
983                 deactivate_locked_super(s);
984
985         return root;
986
987 error_close_devices:
988         btrfs_close_devices(fs_devices);
989 error_fs_info:
990         free_fs_info(fs_info);
991         return ERR_PTR(error);
992 }
993
994 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
995 {
996         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
997         struct btrfs_root *root = fs_info->tree_root;
998         int ret;
999
1000         ret = btrfs_parse_options(root, data);
1001         if (ret)
1002                 return -EINVAL;
1003
1004         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1005                 return 0;
1006
1007         if (*flags & MS_RDONLY) {
1008                 sb->s_flags |= MS_RDONLY;
1009
1010                 ret =  btrfs_commit_super(root);
1011                 WARN_ON(ret);
1012         } else {
1013                 if (fs_info->fs_devices->rw_devices == 0)
1014                         return -EACCES;
1015
1016                 if (btrfs_super_log_root(fs_info->super_copy) != 0)
1017                         return -EINVAL;
1018
1019                 ret = btrfs_cleanup_fs_roots(fs_info);
1020                 WARN_ON(ret);
1021
1022                 /* recover relocation */
1023                 ret = btrfs_recover_relocation(root);
1024                 WARN_ON(ret);
1025
1026                 sb->s_flags &= ~MS_RDONLY;
1027         }
1028
1029         return 0;
1030 }
1031
1032 /* Used to sort the devices by max_avail(descending sort) */
1033 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1034                                        const void *dev_info2)
1035 {
1036         if (((struct btrfs_device_info *)dev_info1)->max_avail >
1037             ((struct btrfs_device_info *)dev_info2)->max_avail)
1038                 return -1;
1039         else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1040                  ((struct btrfs_device_info *)dev_info2)->max_avail)
1041                 return 1;
1042         else
1043         return 0;
1044 }
1045
1046 /*
1047  * sort the devices by max_avail, in which max free extent size of each device
1048  * is stored.(Descending Sort)
1049  */
1050 static inline void btrfs_descending_sort_devices(
1051                                         struct btrfs_device_info *devices,
1052                                         size_t nr_devices)
1053 {
1054         sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1055              btrfs_cmp_device_free_bytes, NULL);
1056 }
1057
1058 /*
1059  * The helper to calc the free space on the devices that can be used to store
1060  * file data.
1061  */
1062 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1063 {
1064         struct btrfs_fs_info *fs_info = root->fs_info;
1065         struct btrfs_device_info *devices_info;
1066         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1067         struct btrfs_device *device;
1068         u64 skip_space;
1069         u64 type;
1070         u64 avail_space;
1071         u64 used_space;
1072         u64 min_stripe_size;
1073         int min_stripes = 1, num_stripes = 1;
1074         int i = 0, nr_devices;
1075         int ret;
1076
1077         nr_devices = fs_info->fs_devices->open_devices;
1078         BUG_ON(!nr_devices);
1079
1080         devices_info = kmalloc(sizeof(*devices_info) * nr_devices,
1081                                GFP_NOFS);
1082         if (!devices_info)
1083                 return -ENOMEM;
1084
1085         /* calc min stripe number for data space alloction */
1086         type = btrfs_get_alloc_profile(root, 1);
1087         if (type & BTRFS_BLOCK_GROUP_RAID0) {
1088                 min_stripes = 2;
1089                 num_stripes = nr_devices;
1090         } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1091                 min_stripes = 2;
1092                 num_stripes = 2;
1093         } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1094                 min_stripes = 4;
1095                 num_stripes = 4;
1096         }
1097
1098         if (type & BTRFS_BLOCK_GROUP_DUP)
1099                 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1100         else
1101                 min_stripe_size = BTRFS_STRIPE_LEN;
1102
1103         list_for_each_entry(device, &fs_devices->devices, dev_list) {
1104                 if (!device->in_fs_metadata || !device->bdev)
1105                         continue;
1106
1107                 avail_space = device->total_bytes - device->bytes_used;
1108
1109                 /* align with stripe_len */
1110                 do_div(avail_space, BTRFS_STRIPE_LEN);
1111                 avail_space *= BTRFS_STRIPE_LEN;
1112
1113                 /*
1114                  * In order to avoid overwritting the superblock on the drive,
1115                  * btrfs starts at an offset of at least 1MB when doing chunk
1116                  * allocation.
1117                  */
1118                 skip_space = 1024 * 1024;
1119
1120                 /* user can set the offset in fs_info->alloc_start. */
1121                 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1122                     device->total_bytes)
1123                         skip_space = max(fs_info->alloc_start, skip_space);
1124
1125                 /*
1126                  * btrfs can not use the free space in [0, skip_space - 1],
1127                  * we must subtract it from the total. In order to implement
1128                  * it, we account the used space in this range first.
1129                  */
1130                 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1131                                                      &used_space);
1132                 if (ret) {
1133                         kfree(devices_info);
1134                         return ret;
1135                 }
1136
1137                 /* calc the free space in [0, skip_space - 1] */
1138                 skip_space -= used_space;
1139
1140                 /*
1141                  * we can use the free space in [0, skip_space - 1], subtract
1142                  * it from the total.
1143                  */
1144                 if (avail_space && avail_space >= skip_space)
1145                         avail_space -= skip_space;
1146                 else
1147                         avail_space = 0;
1148
1149                 if (avail_space < min_stripe_size)
1150                         continue;
1151
1152                 devices_info[i].dev = device;
1153                 devices_info[i].max_avail = avail_space;
1154
1155                 i++;
1156         }
1157
1158         nr_devices = i;
1159
1160         btrfs_descending_sort_devices(devices_info, nr_devices);
1161
1162         i = nr_devices - 1;
1163         avail_space = 0;
1164         while (nr_devices >= min_stripes) {
1165                 if (num_stripes > nr_devices)
1166                         num_stripes = nr_devices;
1167
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 * num_stripes;
1173                         alloc_size = devices_info[i].max_avail;
1174                         for (j = i + 1 - num_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_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1189         struct btrfs_super_block *disk_super = fs_info->super_copy;
1190         struct list_head *head = &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 *)fs_info->fsid;
1196         int ret;
1197
1198         /* holding chunk_muext to avoid allocating new chunks */
1199         mutex_lock(&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(fs_info->tree_root, &total_free_data);
1219         if (ret) {
1220                 mutex_unlock(&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(&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 void btrfs_kill_super(struct super_block *sb)
1240 {
1241         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1242         kill_anon_super(sb);
1243         free_fs_info(fs_info);
1244 }
1245
1246 static struct file_system_type btrfs_fs_type = {
1247         .owner          = THIS_MODULE,
1248         .name           = "btrfs",
1249         .mount          = btrfs_mount,
1250         .kill_sb        = btrfs_kill_super,
1251         .fs_flags       = FS_REQUIRES_DEV,
1252 };
1253
1254 /*
1255  * used by btrfsctl to scan devices when no FS is mounted
1256  */
1257 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1258                                 unsigned long arg)
1259 {
1260         struct btrfs_ioctl_vol_args *vol;
1261         struct btrfs_fs_devices *fs_devices;
1262         int ret = -ENOTTY;
1263
1264         if (!capable(CAP_SYS_ADMIN))
1265                 return -EPERM;
1266
1267         vol = memdup_user((void __user *)arg, sizeof(*vol));
1268         if (IS_ERR(vol))
1269                 return PTR_ERR(vol);
1270
1271         switch (cmd) {
1272         case BTRFS_IOC_SCAN_DEV:
1273                 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1274                                             &btrfs_fs_type, &fs_devices);
1275                 break;
1276         }
1277
1278         kfree(vol);
1279         return ret;
1280 }
1281
1282 static int btrfs_freeze(struct super_block *sb)
1283 {
1284         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1285         mutex_lock(&fs_info->transaction_kthread_mutex);
1286         mutex_lock(&fs_info->cleaner_mutex);
1287         return 0;
1288 }
1289
1290 static int btrfs_unfreeze(struct super_block *sb)
1291 {
1292         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1293         mutex_unlock(&fs_info->cleaner_mutex);
1294         mutex_unlock(&fs_info->transaction_kthread_mutex);
1295         return 0;
1296 }
1297
1298 static void btrfs_fs_dirty_inode(struct inode *inode, int flags)
1299 {
1300         int ret;
1301
1302         ret = btrfs_dirty_inode(inode);
1303         if (ret)
1304                 printk_ratelimited(KERN_ERR "btrfs: fail to dirty inode %Lu "
1305                                    "error %d\n", btrfs_ino(inode), ret);
1306 }
1307
1308 static const struct super_operations btrfs_super_ops = {
1309         .drop_inode     = btrfs_drop_inode,
1310         .evict_inode    = btrfs_evict_inode,
1311         .put_super      = btrfs_put_super,
1312         .sync_fs        = btrfs_sync_fs,
1313         .show_options   = btrfs_show_options,
1314         .write_inode    = btrfs_write_inode,
1315         .dirty_inode    = btrfs_fs_dirty_inode,
1316         .alloc_inode    = btrfs_alloc_inode,
1317         .destroy_inode  = btrfs_destroy_inode,
1318         .statfs         = btrfs_statfs,
1319         .remount_fs     = btrfs_remount,
1320         .freeze_fs      = btrfs_freeze,
1321         .unfreeze_fs    = btrfs_unfreeze,
1322 };
1323
1324 static const struct file_operations btrfs_ctl_fops = {
1325         .unlocked_ioctl  = btrfs_control_ioctl,
1326         .compat_ioctl = btrfs_control_ioctl,
1327         .owner   = THIS_MODULE,
1328         .llseek = noop_llseek,
1329 };
1330
1331 static struct miscdevice btrfs_misc = {
1332         .minor          = BTRFS_MINOR,
1333         .name           = "btrfs-control",
1334         .fops           = &btrfs_ctl_fops
1335 };
1336
1337 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1338 MODULE_ALIAS("devname:btrfs-control");
1339
1340 static int btrfs_interface_init(void)
1341 {
1342         return misc_register(&btrfs_misc);
1343 }
1344
1345 static void btrfs_interface_exit(void)
1346 {
1347         if (misc_deregister(&btrfs_misc) < 0)
1348                 printk(KERN_INFO "misc_deregister failed for control device");
1349 }
1350
1351 static int __init init_btrfs_fs(void)
1352 {
1353         int err;
1354
1355         err = btrfs_init_sysfs();
1356         if (err)
1357                 return err;
1358
1359         err = btrfs_init_compress();
1360         if (err)
1361                 goto free_sysfs;
1362
1363         err = btrfs_init_cachep();
1364         if (err)
1365                 goto free_compress;
1366
1367         err = extent_io_init();
1368         if (err)
1369                 goto free_cachep;
1370
1371         err = extent_map_init();
1372         if (err)
1373                 goto free_extent_io;
1374
1375         err = btrfs_delayed_inode_init();
1376         if (err)
1377                 goto free_extent_map;
1378
1379         err = btrfs_interface_init();
1380         if (err)
1381                 goto free_delayed_inode;
1382
1383         err = register_filesystem(&btrfs_fs_type);
1384         if (err)
1385                 goto unregister_ioctl;
1386
1387         printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
1388         return 0;
1389
1390 unregister_ioctl:
1391         btrfs_interface_exit();
1392 free_delayed_inode:
1393         btrfs_delayed_inode_exit();
1394 free_extent_map:
1395         extent_map_exit();
1396 free_extent_io:
1397         extent_io_exit();
1398 free_cachep:
1399         btrfs_destroy_cachep();
1400 free_compress:
1401         btrfs_exit_compress();
1402 free_sysfs:
1403         btrfs_exit_sysfs();
1404         return err;
1405 }
1406
1407 static void __exit exit_btrfs_fs(void)
1408 {
1409         btrfs_destroy_cachep();
1410         btrfs_delayed_inode_exit();
1411         extent_map_exit();
1412         extent_io_exit();
1413         btrfs_interface_exit();
1414         unregister_filesystem(&btrfs_fs_type);
1415         btrfs_exit_sysfs();
1416         btrfs_cleanup_fs_uuids();
1417         btrfs_exit_compress();
1418 }
1419
1420 module_init(init_btrfs_fs)
1421 module_exit(exit_btrfs_fs)
1422
1423 MODULE_LICENSE("GPL");