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Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux/fpc-iii.git] / fs / btrfs / super.c
blobd04db817be5c8271f531d87d0ee9a4a950f616f8
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 <linux/btrfs.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 "print-tree.h"
51 #include "hash.h"
52 #include "props.h"
53 #include "xattr.h"
54 #include "volumes.h"
55 #include "export.h"
56 #include "compression.h"
57 #include "rcu-string.h"
58 #include "dev-replace.h"
59 #include "free-space-cache.h"
60 #include "backref.h"
61 #include "tests/btrfs-tests.h"
62
63 #define CREATE_TRACE_POINTS
64 #include <trace/events/btrfs.h>
65
66 static const struct super_operations btrfs_super_ops;
67 static struct file_system_type btrfs_fs_type;
68
69 static const char *btrfs_decode_error(int errno)
70 {
71 char *errstr = "unknown";
72
73 switch (errno) {
74 case -EIO:
75 errstr = "IO failure";
76 break;
77 case -ENOMEM:
78 errstr = "Out of memory";
79 break;
80 case -EROFS:
81 errstr = "Readonly filesystem";
82 break;
83 case -EEXIST:
84 errstr = "Object already exists";
85 break;
86 case -ENOSPC:
87 errstr = "No space left";
88 break;
89 case -ENOENT:
90 errstr = "No such entry";
91 break;
92 }
93
94 return errstr;
95 }
96
97 static void save_error_info(struct btrfs_fs_info *fs_info)
98 {
99 /*
100 * today we only save the error info into ram. Long term we'll
101 * also send it down to the disk
102 */
103 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
104 }
105
106 /* btrfs handle error by forcing the filesystem readonly */
107 static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
108 {
109 struct super_block *sb = fs_info->sb;
110
111 if (sb->s_flags & MS_RDONLY)
112 return;
113
114 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
115 sb->s_flags |= MS_RDONLY;
116 btrfs_info(fs_info, "forced readonly");
117 /*
118 * Note that a running device replace operation is not
119 * canceled here although there is no way to update
120 * the progress. It would add the risk of a deadlock,
121 * therefore the canceling is ommited. The only penalty
122 * is that some I/O remains active until the procedure
123 * completes. The next time when the filesystem is
124 * mounted writeable again, the device replace
125 * operation continues.
126 */
127 }
128 }
129
130 #ifdef CONFIG_PRINTK
131 /*
132 * __btrfs_std_error decodes expected errors from the caller and
133 * invokes the approciate error response.
134 */
135 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
136 unsigned int line, int errno, const char *fmt, ...)
137 {
138 struct super_block *sb = fs_info->sb;
139 const char *errstr;
140
141 /*
142 * Special case: if the error is EROFS, and we're already
143 * under MS_RDONLY, then it is safe here.
144 */
145 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
146 return;
147
148 errstr = btrfs_decode_error(errno);
149 if (fmt) {
150 struct va_format vaf;
151 va_list args;
152
153 va_start(args, fmt);
154 vaf.fmt = fmt;
155 vaf.va = &args;
156
157 printk(KERN_CRIT
158 "BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
159 sb->s_id, function, line, errno, errstr, &vaf);
160 va_end(args);
161 } else {
162 printk(KERN_CRIT "BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
163 sb->s_id, function, line, errno, errstr);
164 }
165
166 /* Don't go through full error handling during mount */
167 save_error_info(fs_info);
168 if (sb->s_flags & MS_BORN)
169 btrfs_handle_error(fs_info);
170 }
171
172 static const char * const logtypes[] = {
173 "emergency",
174 "alert",
175 "critical",
176 "error",
177 "warning",
178 "notice",
179 "info",
180 "debug",
181 };
182
183 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
184 {
185 struct super_block *sb = fs_info->sb;
186 char lvl[4];
187 struct va_format vaf;
188 va_list args;
189 const char *type = logtypes[4];
190 int kern_level;
191
192 va_start(args, fmt);
193
194 kern_level = printk_get_level(fmt);
195 if (kern_level) {
196 size_t size = printk_skip_level(fmt) - fmt;
197 memcpy(lvl, fmt, size);
198 lvl[size] = '\0';
199 fmt += size;
200 type = logtypes[kern_level - '0'];
201 } else
202 *lvl = '\0';
203
204 vaf.fmt = fmt;
205 vaf.va = &args;
206
207 printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
208
209 va_end(args);
210 }
211
212 #else
213
214 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
215 unsigned int line, int errno, const char *fmt, ...)
216 {
217 struct super_block *sb = fs_info->sb;
218
219 /*
220 * Special case: if the error is EROFS, and we're already
221 * under MS_RDONLY, then it is safe here.
222 */
223 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
224 return;
225
226 /* Don't go through full error handling during mount */
227 if (sb->s_flags & MS_BORN) {
228 save_error_info(fs_info);
229 btrfs_handle_error(fs_info);
230 }
231 }
232 #endif
233
234 /*
235 * We only mark the transaction aborted and then set the file system read-only.
236 * This will prevent new transactions from starting or trying to join this
237 * one.
238 *
239 * This means that error recovery at the call site is limited to freeing
240 * any local memory allocations and passing the error code up without
241 * further cleanup. The transaction should complete as it normally would
242 * in the call path but will return -EIO.
243 *
244 * We'll complete the cleanup in btrfs_end_transaction and
245 * btrfs_commit_transaction.
246 */
247 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
248 struct btrfs_root *root, const char *function,
249 unsigned int line, int errno)
250 {
251 /*
252 * Report first abort since mount
253 */
254 if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED,
255 &root->fs_info->fs_state)) {
256 WARN(1, KERN_DEBUG "BTRFS: Transaction aborted (error %d)\n",
257 errno);
258 }
259 trans->aborted = errno;
260 /* Nothing used. The other threads that have joined this
261 * transaction may be able to continue. */
262 if (!trans->blocks_used) {
263 const char *errstr;
264
265 errstr = btrfs_decode_error(errno);
266 btrfs_warn(root->fs_info,
267 "%s:%d: Aborting unused transaction(%s).",
268 function, line, errstr);
269 return;
270 }
271 ACCESS_ONCE(trans->transaction->aborted) = errno;
272 /* Wake up anybody who may be waiting on this transaction */
273 wake_up(&root->fs_info->transaction_wait);
274 wake_up(&root->fs_info->transaction_blocked_wait);
275 __btrfs_std_error(root->fs_info, function, line, errno, NULL);
276 }
277 /*
278 * __btrfs_panic decodes unexpected, fatal errors from the caller,
279 * issues an alert, and either panics or BUGs, depending on mount options.
280 */
281 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
282 unsigned int line, int errno, const char *fmt, ...)
283 {
284 char *s_id = "<unknown>";
285 const char *errstr;
286 struct va_format vaf = { .fmt = fmt };
287 va_list args;
288
289 if (fs_info)
290 s_id = fs_info->sb->s_id;
291
292 va_start(args, fmt);
293 vaf.va = &args;
294
295 errstr = btrfs_decode_error(errno);
296 if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
297 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
298 s_id, function, line, &vaf, errno, errstr);
299
300 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
301 function, line, &vaf, errno, errstr);
302 va_end(args);
303 /* Caller calls BUG() */
304 }
305
306 static void btrfs_put_super(struct super_block *sb)
307 {
308 (void)close_ctree(btrfs_sb(sb)->tree_root);
309 /* FIXME: need to fix VFS to return error? */
310 /* AV: return it _where_? ->put_super() can be triggered by any number
311 * of async events, up to and including delivery of SIGKILL to the
312 * last process that kept it busy. Or segfault in the aforementioned
313 * process... Whom would you report that to?
314 */
315 }
316
317 enum {
318 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
319 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
320 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
321 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
322 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
323 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
324 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
325 Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
326 Opt_check_integrity, Opt_check_integrity_including_extent_data,
327 Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree,
328 Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard,
329 Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow,
330 Opt_datasum, Opt_treelog, Opt_noinode_cache,
331 Opt_err,
332 };
333
334 static match_table_t tokens = {
335 {Opt_degraded, "degraded"},
336 {Opt_subvol, "subvol=%s"},
337 {Opt_subvolid, "subvolid=%s"},
338 {Opt_device, "device=%s"},
339 {Opt_nodatasum, "nodatasum"},
340 {Opt_datasum, "datasum"},
341 {Opt_nodatacow, "nodatacow"},
342 {Opt_datacow, "datacow"},
343 {Opt_nobarrier, "nobarrier"},
344 {Opt_barrier, "barrier"},
345 {Opt_max_inline, "max_inline=%s"},
346 {Opt_alloc_start, "alloc_start=%s"},
347 {Opt_thread_pool, "thread_pool=%d"},
348 {Opt_compress, "compress"},
349 {Opt_compress_type, "compress=%s"},
350 {Opt_compress_force, "compress-force"},
351 {Opt_compress_force_type, "compress-force=%s"},
352 {Opt_ssd, "ssd"},
353 {Opt_ssd_spread, "ssd_spread"},
354 {Opt_nossd, "nossd"},
355 {Opt_acl, "acl"},
356 {Opt_noacl, "noacl"},
357 {Opt_notreelog, "notreelog"},
358 {Opt_treelog, "treelog"},
359 {Opt_flushoncommit, "flushoncommit"},
360 {Opt_noflushoncommit, "noflushoncommit"},
361 {Opt_ratio, "metadata_ratio=%d"},
362 {Opt_discard, "discard"},
363 {Opt_nodiscard, "nodiscard"},
364 {Opt_space_cache, "space_cache"},
365 {Opt_clear_cache, "clear_cache"},
366 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
367 {Opt_enospc_debug, "enospc_debug"},
368 {Opt_noenospc_debug, "noenospc_debug"},
369 {Opt_subvolrootid, "subvolrootid=%d"},
370 {Opt_defrag, "autodefrag"},
371 {Opt_nodefrag, "noautodefrag"},
372 {Opt_inode_cache, "inode_cache"},
373 {Opt_noinode_cache, "noinode_cache"},
374 {Opt_no_space_cache, "nospace_cache"},
375 {Opt_recovery, "recovery"},
376 {Opt_skip_balance, "skip_balance"},
377 {Opt_check_integrity, "check_int"},
378 {Opt_check_integrity_including_extent_data, "check_int_data"},
379 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
380 {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
381 {Opt_fatal_errors, "fatal_errors=%s"},
382 {Opt_commit_interval, "commit=%d"},
383 {Opt_err, NULL},
384 };
385
386 #define btrfs_set_and_info(root, opt, fmt, args...) \
387 { \
388 if (!btrfs_test_opt(root, opt)) \
389 btrfs_info(root->fs_info, fmt, ##args); \
390 btrfs_set_opt(root->fs_info->mount_opt, opt); \
391 }
392
393 #define btrfs_clear_and_info(root, opt, fmt, args...) \
394 { \
395 if (btrfs_test_opt(root, opt)) \
396 btrfs_info(root->fs_info, fmt, ##args); \
397 btrfs_clear_opt(root->fs_info->mount_opt, opt); \
398 }
399
400 /*
401 * Regular mount options parser. Everything that is needed only when
402 * reading in a new superblock is parsed here.
403 * XXX JDM: This needs to be cleaned up for remount.
404 */
405 int btrfs_parse_options(struct btrfs_root *root, char *options)
406 {
407 struct btrfs_fs_info *info = root->fs_info;
408 substring_t args[MAX_OPT_ARGS];
409 char *p, *num, *orig = NULL;
410 u64 cache_gen;
411 int intarg;
412 int ret = 0;
413 char *compress_type;
414 bool compress_force = false;
415 bool compress = false;
416
417 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
418 if (cache_gen)
419 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
420
421 if (!options)
422 goto out;
423
424 /*
425 * strsep changes the string, duplicate it because parse_options
426 * gets called twice
427 */
428 options = kstrdup(options, GFP_NOFS);
429 if (!options)
430 return -ENOMEM;
431
432 orig = options;
433
434 while ((p = strsep(&options, ",")) != NULL) {
435 int token;
436 if (!*p)
437 continue;
438
439 token = match_token(p, tokens, args);
440 switch (token) {
441 case Opt_degraded:
442 btrfs_info(root->fs_info, "allowing degraded mounts");
443 btrfs_set_opt(info->mount_opt, DEGRADED);
444 break;
445 case Opt_subvol:
446 case Opt_subvolid:
447 case Opt_subvolrootid:
448 case Opt_device:
449 /*
450 * These are parsed by btrfs_parse_early_options
451 * and can be happily ignored here.
452 */
453 break;
454 case Opt_nodatasum:
455 btrfs_set_and_info(root, NODATASUM,
456 "setting nodatasum");
457 break;
458 case Opt_datasum:
459 if (btrfs_test_opt(root, NODATASUM)) {
460 if (btrfs_test_opt(root, NODATACOW))
461 btrfs_info(root->fs_info, "setting datasum, datacow enabled");
462 else
463 btrfs_info(root->fs_info, "setting datasum");
464 }
465 btrfs_clear_opt(info->mount_opt, NODATACOW);
466 btrfs_clear_opt(info->mount_opt, NODATASUM);
467 break;
468 case Opt_nodatacow:
469 if (!btrfs_test_opt(root, NODATACOW)) {
470 if (!btrfs_test_opt(root, COMPRESS) ||
471 !btrfs_test_opt(root, FORCE_COMPRESS)) {
472 btrfs_info(root->fs_info,
473 "setting nodatacow, compression disabled");
474 } else {
475 btrfs_info(root->fs_info, "setting nodatacow");
476 }
477 }
478 btrfs_clear_opt(info->mount_opt, COMPRESS);
479 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
480 btrfs_set_opt(info->mount_opt, NODATACOW);
481 btrfs_set_opt(info->mount_opt, NODATASUM);
482 break;
483 case Opt_datacow:
484 btrfs_clear_and_info(root, NODATACOW,
485 "setting datacow");
486 break;
487 case Opt_compress_force:
488 case Opt_compress_force_type:
489 compress_force = true;
490 /* Fallthrough */
491 case Opt_compress:
492 case Opt_compress_type:
493 compress = true;
494 if (token == Opt_compress ||
495 token == Opt_compress_force ||
496 strcmp(args[0].from, "zlib") == 0) {
497 compress_type = "zlib";
498 info->compress_type = BTRFS_COMPRESS_ZLIB;
499 btrfs_set_opt(info->mount_opt, COMPRESS);
500 btrfs_clear_opt(info->mount_opt, NODATACOW);
501 btrfs_clear_opt(info->mount_opt, NODATASUM);
502 } else if (strcmp(args[0].from, "lzo") == 0) {
503 compress_type = "lzo";
504 info->compress_type = BTRFS_COMPRESS_LZO;
505 btrfs_set_opt(info->mount_opt, COMPRESS);
506 btrfs_clear_opt(info->mount_opt, NODATACOW);
507 btrfs_clear_opt(info->mount_opt, NODATASUM);
508 btrfs_set_fs_incompat(info, COMPRESS_LZO);
509 } else if (strncmp(args[0].from, "no", 2) == 0) {
510 compress_type = "no";
511 btrfs_clear_opt(info->mount_opt, COMPRESS);
512 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
513 compress_force = false;
514 } else {
515 ret = -EINVAL;
516 goto out;
517 }
518
519 if (compress_force) {
520 btrfs_set_and_info(root, FORCE_COMPRESS,
521 "force %s compression",
522 compress_type);
523 } else if (compress) {
524 if (!btrfs_test_opt(root, COMPRESS))
525 btrfs_info(root->fs_info,
526 "btrfs: use %s compression\n",
527 compress_type);
528 }
529 break;
530 case Opt_ssd:
531 btrfs_set_and_info(root, SSD,
532 "use ssd allocation scheme");
533 break;
534 case Opt_ssd_spread:
535 btrfs_set_and_info(root, SSD_SPREAD,
536 "use spread ssd allocation scheme");
537 break;
538 case Opt_nossd:
539 btrfs_clear_and_info(root, NOSSD,
540 "not using ssd allocation scheme");
541 btrfs_clear_opt(info->mount_opt, SSD);
542 break;
543 case Opt_barrier:
544 btrfs_clear_and_info(root, NOBARRIER,
545 "turning on barriers");
546 break;
547 case Opt_nobarrier:
548 btrfs_set_and_info(root, NOBARRIER,
549 "turning off barriers");
550 break;
551 case Opt_thread_pool:
552 ret = match_int(&args[0], &intarg);
553 if (ret) {
554 goto out;
555 } else if (intarg > 0) {
556 info->thread_pool_size = intarg;
557 } else {
558 ret = -EINVAL;
559 goto out;
560 }
561 break;
562 case Opt_max_inline:
563 num = match_strdup(&args[0]);
564 if (num) {
565 info->max_inline = memparse(num, NULL);
566 kfree(num);
567
568 if (info->max_inline) {
569 info->max_inline = min_t(u64,
570 info->max_inline,
571 root->sectorsize);
572 }
573 btrfs_info(root->fs_info, "max_inline at %llu",
574 info->max_inline);
575 } else {
576 ret = -ENOMEM;
577 goto out;
578 }
579 break;
580 case Opt_alloc_start:
581 num = match_strdup(&args[0]);
582 if (num) {
583 mutex_lock(&info->chunk_mutex);
584 info->alloc_start = memparse(num, NULL);
585 mutex_unlock(&info->chunk_mutex);
586 kfree(num);
587 btrfs_info(root->fs_info, "allocations start at %llu",
588 info->alloc_start);
589 } else {
590 ret = -ENOMEM;
591 goto out;
592 }
593 break;
594 case Opt_acl:
595 root->fs_info->sb->s_flags |= MS_POSIXACL;
596 break;
597 case Opt_noacl:
598 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
599 break;
600 case Opt_notreelog:
601 btrfs_set_and_info(root, NOTREELOG,
602 "disabling tree log");
603 break;
604 case Opt_treelog:
605 btrfs_clear_and_info(root, NOTREELOG,
606 "enabling tree log");
607 break;
608 case Opt_flushoncommit:
609 btrfs_set_and_info(root, FLUSHONCOMMIT,
610 "turning on flush-on-commit");
611 break;
612 case Opt_noflushoncommit:
613 btrfs_clear_and_info(root, FLUSHONCOMMIT,
614 "turning off flush-on-commit");
615 break;
616 case Opt_ratio:
617 ret = match_int(&args[0], &intarg);
618 if (ret) {
619 goto out;
620 } else if (intarg >= 0) {
621 info->metadata_ratio = intarg;
622 btrfs_info(root->fs_info, "metadata ratio %d",
623 info->metadata_ratio);
624 } else {
625 ret = -EINVAL;
626 goto out;
627 }
628 break;
629 case Opt_discard:
630 btrfs_set_and_info(root, DISCARD,
631 "turning on discard");
632 break;
633 case Opt_nodiscard:
634 btrfs_clear_and_info(root, DISCARD,
635 "turning off discard");
636 break;
637 case Opt_space_cache:
638 btrfs_set_and_info(root, SPACE_CACHE,
639 "enabling disk space caching");
640 break;
641 case Opt_rescan_uuid_tree:
642 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
643 break;
644 case Opt_no_space_cache:
645 btrfs_clear_and_info(root, SPACE_CACHE,
646 "disabling disk space caching");
647 break;
648 case Opt_inode_cache:
649 btrfs_set_and_info(root, CHANGE_INODE_CACHE,
650 "enabling inode map caching");
651 break;
652 case Opt_noinode_cache:
653 btrfs_clear_and_info(root, CHANGE_INODE_CACHE,
654 "disabling inode map caching");
655 break;
656 case Opt_clear_cache:
657 btrfs_set_and_info(root, CLEAR_CACHE,
658 "force clearing of disk cache");
659 break;
660 case Opt_user_subvol_rm_allowed:
661 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
662 break;
663 case Opt_enospc_debug:
664 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
665 break;
666 case Opt_noenospc_debug:
667 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
668 break;
669 case Opt_defrag:
670 btrfs_set_and_info(root, AUTO_DEFRAG,
671 "enabling auto defrag");
672 break;
673 case Opt_nodefrag:
674 btrfs_clear_and_info(root, AUTO_DEFRAG,
675 "disabling auto defrag");
676 break;
677 case Opt_recovery:
678 btrfs_info(root->fs_info, "enabling auto recovery");
679 btrfs_set_opt(info->mount_opt, RECOVERY);
680 break;
681 case Opt_skip_balance:
682 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
683 break;
684 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
685 case Opt_check_integrity_including_extent_data:
686 btrfs_info(root->fs_info,
687 "enabling check integrity including extent data");
688 btrfs_set_opt(info->mount_opt,
689 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
690 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
691 break;
692 case Opt_check_integrity:
693 btrfs_info(root->fs_info, "enabling check integrity");
694 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
695 break;
696 case Opt_check_integrity_print_mask:
697 ret = match_int(&args[0], &intarg);
698 if (ret) {
699 goto out;
700 } else if (intarg >= 0) {
701 info->check_integrity_print_mask = intarg;
702 btrfs_info(root->fs_info, "check_integrity_print_mask 0x%x",
703 info->check_integrity_print_mask);
704 } else {
705 ret = -EINVAL;
706 goto out;
707 }
708 break;
709 #else
710 case Opt_check_integrity_including_extent_data:
711 case Opt_check_integrity:
712 case Opt_check_integrity_print_mask:
713 btrfs_err(root->fs_info,
714 "support for check_integrity* not compiled in!");
715 ret = -EINVAL;
716 goto out;
717 #endif
718 case Opt_fatal_errors:
719 if (strcmp(args[0].from, "panic") == 0)
720 btrfs_set_opt(info->mount_opt,
721 PANIC_ON_FATAL_ERROR);
722 else if (strcmp(args[0].from, "bug") == 0)
723 btrfs_clear_opt(info->mount_opt,
724 PANIC_ON_FATAL_ERROR);
725 else {
726 ret = -EINVAL;
727 goto out;
728 }
729 break;
730 case Opt_commit_interval:
731 intarg = 0;
732 ret = match_int(&args[0], &intarg);
733 if (ret < 0) {
734 btrfs_err(root->fs_info, "invalid commit interval");
735 ret = -EINVAL;
736 goto out;
737 }
738 if (intarg > 0) {
739 if (intarg > 300) {
740 btrfs_warn(root->fs_info, "excessive commit interval %d",
741 intarg);
742 }
743 info->commit_interval = intarg;
744 } else {
745 btrfs_info(root->fs_info, "using default commit interval %ds",
746 BTRFS_DEFAULT_COMMIT_INTERVAL);
747 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
748 }
749 break;
750 case Opt_err:
751 btrfs_info(root->fs_info, "unrecognized mount option '%s'", p);
752 ret = -EINVAL;
753 goto out;
754 default:
755 break;
756 }
757 }
758 out:
759 if (!ret && btrfs_test_opt(root, SPACE_CACHE))
760 btrfs_info(root->fs_info, "disk space caching is enabled");
761 kfree(orig);
762 return ret;
763 }
764
765 /*
766 * Parse mount options that are required early in the mount process.
767 *
768 * All other options will be parsed on much later in the mount process and
769 * only when we need to allocate a new super block.
770 */
771 static int btrfs_parse_early_options(const char *options, fmode_t flags,
772 void *holder, char **subvol_name, u64 *subvol_objectid,
773 struct btrfs_fs_devices **fs_devices)
774 {
775 substring_t args[MAX_OPT_ARGS];
776 char *device_name, *opts, *orig, *p;
777 char *num = NULL;
778 int error = 0;
779
780 if (!options)
781 return 0;
782
783 /*
784 * strsep changes the string, duplicate it because parse_options
785 * gets called twice
786 */
787 opts = kstrdup(options, GFP_KERNEL);
788 if (!opts)
789 return -ENOMEM;
790 orig = opts;
791
792 while ((p = strsep(&opts, ",")) != NULL) {
793 int token;
794 if (!*p)
795 continue;
796
797 token = match_token(p, tokens, args);
798 switch (token) {
799 case Opt_subvol:
800 kfree(*subvol_name);
801 *subvol_name = match_strdup(&args[0]);
802 if (!*subvol_name) {
803 error = -ENOMEM;
804 goto out;
805 }
806 break;
807 case Opt_subvolid:
808 num = match_strdup(&args[0]);
809 if (num) {
810 *subvol_objectid = memparse(num, NULL);
811 kfree(num);
812 /* we want the original fs_tree */
813 if (!*subvol_objectid)
814 *subvol_objectid =
815 BTRFS_FS_TREE_OBJECTID;
816 } else {
817 error = -EINVAL;
818 goto out;
819 }
820 break;
821 case Opt_subvolrootid:
822 printk(KERN_WARNING
823 "BTRFS: 'subvolrootid' mount option is deprecated and has "
824 "no effect\n");
825 break;
826 case Opt_device:
827 device_name = match_strdup(&args[0]);
828 if (!device_name) {
829 error = -ENOMEM;
830 goto out;
831 }
832 error = btrfs_scan_one_device(device_name,
833 flags, holder, fs_devices);
834 kfree(device_name);
835 if (error)
836 goto out;
837 break;
838 default:
839 break;
840 }
841 }
842
843 out:
844 kfree(orig);
845 return error;
846 }
847
848 static struct dentry *get_default_root(struct super_block *sb,
849 u64 subvol_objectid)
850 {
851 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
852 struct btrfs_root *root = fs_info->tree_root;
853 struct btrfs_root *new_root;
854 struct btrfs_dir_item *di;
855 struct btrfs_path *path;
856 struct btrfs_key location;
857 struct inode *inode;
858 struct dentry *dentry;
859 u64 dir_id;
860 int new = 0;
861
862 /*
863 * We have a specific subvol we want to mount, just setup location and
864 * go look up the root.
865 */
866 if (subvol_objectid) {
867 location.objectid = subvol_objectid;
868 location.type = BTRFS_ROOT_ITEM_KEY;
869 location.offset = (u64)-1;
870 goto find_root;
871 }
872
873 path = btrfs_alloc_path();
874 if (!path)
875 return ERR_PTR(-ENOMEM);
876 path->leave_spinning = 1;
877
878 /*
879 * Find the "default" dir item which points to the root item that we
880 * will mount by default if we haven't been given a specific subvolume
881 * to mount.
882 */
883 dir_id = btrfs_super_root_dir(fs_info->super_copy);
884 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
885 if (IS_ERR(di)) {
886 btrfs_free_path(path);
887 return ERR_CAST(di);
888 }
889 if (!di) {
890 /*
891 * Ok the default dir item isn't there. This is weird since
892 * it's always been there, but don't freak out, just try and
893 * mount to root most subvolume.
894 */
895 btrfs_free_path(path);
896 dir_id = BTRFS_FIRST_FREE_OBJECTID;
897 new_root = fs_info->fs_root;
898 goto setup_root;
899 }
900
901 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
902 btrfs_free_path(path);
903
904 find_root:
905 new_root = btrfs_read_fs_root_no_name(fs_info, &location);
906 if (IS_ERR(new_root))
907 return ERR_CAST(new_root);
908
909 dir_id = btrfs_root_dirid(&new_root->root_item);
910 setup_root:
911 location.objectid = dir_id;
912 location.type = BTRFS_INODE_ITEM_KEY;
913 location.offset = 0;
914
915 inode = btrfs_iget(sb, &location, new_root, &new);
916 if (IS_ERR(inode))
917 return ERR_CAST(inode);
918
919 /*
920 * If we're just mounting the root most subvol put the inode and return
921 * a reference to the dentry. We will have already gotten a reference
922 * to the inode in btrfs_fill_super so we're good to go.
923 */
924 if (!new && sb->s_root->d_inode == inode) {
925 iput(inode);
926 return dget(sb->s_root);
927 }
928
929 dentry = d_obtain_alias(inode);
930 if (!IS_ERR(dentry)) {
931 spin_lock(&dentry->d_lock);
932 dentry->d_flags &= ~DCACHE_DISCONNECTED;
933 spin_unlock(&dentry->d_lock);
934 }
935 return dentry;
936 }
937
938 static int btrfs_fill_super(struct super_block *sb,
939 struct btrfs_fs_devices *fs_devices,
940 void *data, int silent)
941 {
942 struct inode *inode;
943 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
944 struct btrfs_key key;
945 int err;
946
947 sb->s_maxbytes = MAX_LFS_FILESIZE;
948 sb->s_magic = BTRFS_SUPER_MAGIC;
949 sb->s_op = &btrfs_super_ops;
950 sb->s_d_op = &btrfs_dentry_operations;
951 sb->s_export_op = &btrfs_export_ops;
952 sb->s_xattr = btrfs_xattr_handlers;
953 sb->s_time_gran = 1;
954 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
955 sb->s_flags |= MS_POSIXACL;
956 #endif
957 sb->s_flags |= MS_I_VERSION;
958 err = open_ctree(sb, fs_devices, (char *)data);
959 if (err) {
960 printk(KERN_ERR "BTRFS: open_ctree failed\n");
961 return err;
962 }
963
964 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
965 key.type = BTRFS_INODE_ITEM_KEY;
966 key.offset = 0;
967 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
968 if (IS_ERR(inode)) {
969 err = PTR_ERR(inode);
970 goto fail_close;
971 }
972
973 sb->s_root = d_make_root(inode);
974 if (!sb->s_root) {
975 err = -ENOMEM;
976 goto fail_close;
977 }
978
979 save_mount_options(sb, data);
980 cleancache_init_fs(sb);
981 sb->s_flags |= MS_ACTIVE;
982 return 0;
983
984 fail_close:
985 close_ctree(fs_info->tree_root);
986 return err;
987 }
988
989 int btrfs_sync_fs(struct super_block *sb, int wait)
990 {
991 struct btrfs_trans_handle *trans;
992 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
993 struct btrfs_root *root = fs_info->tree_root;
994
995 trace_btrfs_sync_fs(wait);
996
997 if (!wait) {
998 filemap_flush(fs_info->btree_inode->i_mapping);
999 return 0;
1000 }
1001
1002 btrfs_wait_ordered_roots(fs_info, -1);
1003
1004 trans = btrfs_attach_transaction_barrier(root);
1005 if (IS_ERR(trans)) {
1006 /* no transaction, don't bother */
1007 if (PTR_ERR(trans) == -ENOENT)
1008 return 0;
1009 return PTR_ERR(trans);
1010 }
1011 return btrfs_commit_transaction(trans, root);
1012 }
1013
1014 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
1015 {
1016 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
1017 struct btrfs_root *root = info->tree_root;
1018 char *compress_type;
1019
1020 if (btrfs_test_opt(root, DEGRADED))
1021 seq_puts(seq, ",degraded");
1022 if (btrfs_test_opt(root, NODATASUM))
1023 seq_puts(seq, ",nodatasum");
1024 if (btrfs_test_opt(root, NODATACOW))
1025 seq_puts(seq, ",nodatacow");
1026 if (btrfs_test_opt(root, NOBARRIER))
1027 seq_puts(seq, ",nobarrier");
1028 if (info->max_inline != 8192 * 1024)
1029 seq_printf(seq, ",max_inline=%llu", info->max_inline);
1030 if (info->alloc_start != 0)
1031 seq_printf(seq, ",alloc_start=%llu", info->alloc_start);
1032 if (info->thread_pool_size != min_t(unsigned long,
1033 num_online_cpus() + 2, 8))
1034 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
1035 if (btrfs_test_opt(root, COMPRESS)) {
1036 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
1037 compress_type = "zlib";
1038 else
1039 compress_type = "lzo";
1040 if (btrfs_test_opt(root, FORCE_COMPRESS))
1041 seq_printf(seq, ",compress-force=%s", compress_type);
1042 else
1043 seq_printf(seq, ",compress=%s", compress_type);
1044 }
1045 if (btrfs_test_opt(root, NOSSD))
1046 seq_puts(seq, ",nossd");
1047 if (btrfs_test_opt(root, SSD_SPREAD))
1048 seq_puts(seq, ",ssd_spread");
1049 else if (btrfs_test_opt(root, SSD))
1050 seq_puts(seq, ",ssd");
1051 if (btrfs_test_opt(root, NOTREELOG))
1052 seq_puts(seq, ",notreelog");
1053 if (btrfs_test_opt(root, FLUSHONCOMMIT))
1054 seq_puts(seq, ",flushoncommit");
1055 if (btrfs_test_opt(root, DISCARD))
1056 seq_puts(seq, ",discard");
1057 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
1058 seq_puts(seq, ",noacl");
1059 if (btrfs_test_opt(root, SPACE_CACHE))
1060 seq_puts(seq, ",space_cache");
1061 else
1062 seq_puts(seq, ",nospace_cache");
1063 if (btrfs_test_opt(root, RESCAN_UUID_TREE))
1064 seq_puts(seq, ",rescan_uuid_tree");
1065 if (btrfs_test_opt(root, CLEAR_CACHE))
1066 seq_puts(seq, ",clear_cache");
1067 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1068 seq_puts(seq, ",user_subvol_rm_allowed");
1069 if (btrfs_test_opt(root, ENOSPC_DEBUG))
1070 seq_puts(seq, ",enospc_debug");
1071 if (btrfs_test_opt(root, AUTO_DEFRAG))
1072 seq_puts(seq, ",autodefrag");
1073 if (btrfs_test_opt(root, INODE_MAP_CACHE))
1074 seq_puts(seq, ",inode_cache");
1075 if (btrfs_test_opt(root, SKIP_BALANCE))
1076 seq_puts(seq, ",skip_balance");
1077 if (btrfs_test_opt(root, RECOVERY))
1078 seq_puts(seq, ",recovery");
1079 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1080 if (btrfs_test_opt(root, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1081 seq_puts(seq, ",check_int_data");
1082 else if (btrfs_test_opt(root, CHECK_INTEGRITY))
1083 seq_puts(seq, ",check_int");
1084 if (info->check_integrity_print_mask)
1085 seq_printf(seq, ",check_int_print_mask=%d",
1086 info->check_integrity_print_mask);
1087 #endif
1088 if (info->metadata_ratio)
1089 seq_printf(seq, ",metadata_ratio=%d",
1090 info->metadata_ratio);
1091 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
1092 seq_puts(seq, ",fatal_errors=panic");
1093 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1094 seq_printf(seq, ",commit=%d", info->commit_interval);
1095 return 0;
1096 }
1097
1098 static int btrfs_test_super(struct super_block *s, void *data)
1099 {
1100 struct btrfs_fs_info *p = data;
1101 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1102
1103 return fs_info->fs_devices == p->fs_devices;
1104 }
1105
1106 static int btrfs_set_super(struct super_block *s, void *data)
1107 {
1108 int err = set_anon_super(s, data);
1109 if (!err)
1110 s->s_fs_info = data;
1111 return err;
1112 }
1113
1114 /*
1115 * subvolumes are identified by ino 256
1116 */
1117 static inline int is_subvolume_inode(struct inode *inode)
1118 {
1119 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1120 return 1;
1121 return 0;
1122 }
1123
1124 /*
1125 * This will strip out the subvol=%s argument for an argument string and add
1126 * subvolid=0 to make sure we get the actual tree root for path walking to the
1127 * subvol we want.
1128 */
1129 static char *setup_root_args(char *args)
1130 {
1131 unsigned len = strlen(args) + 2 + 1;
1132 char *src, *dst, *buf;
1133
1134 /*
1135 * We need the same args as before, but with this substitution:
1136 * s!subvol=[^,]+!subvolid=0!
1137 *
1138 * Since the replacement string is up to 2 bytes longer than the
1139 * original, allocate strlen(args) + 2 + 1 bytes.
1140 */
1141
1142 src = strstr(args, "subvol=");
1143 /* This shouldn't happen, but just in case.. */
1144 if (!src)
1145 return NULL;
1146
1147 buf = dst = kmalloc(len, GFP_NOFS);
1148 if (!buf)
1149 return NULL;
1150
1151 /*
1152 * If the subvol= arg is not at the start of the string,
1153 * copy whatever precedes it into buf.
1154 */
1155 if (src != args) {
1156 *src++ = '\0';
1157 strcpy(buf, args);
1158 dst += strlen(args);
1159 }
1160
1161 strcpy(dst, "subvolid=0");
1162 dst += strlen("subvolid=0");
1163
1164 /*
1165 * If there is a "," after the original subvol=... string,
1166 * copy that suffix into our buffer. Otherwise, we're done.
1167 */
1168 src = strchr(src, ',');
1169 if (src)
1170 strcpy(dst, src);
1171
1172 return buf;
1173 }
1174
1175 static struct dentry *mount_subvol(const char *subvol_name, int flags,
1176 const char *device_name, char *data)
1177 {
1178 struct dentry *root;
1179 struct vfsmount *mnt;
1180 char *newargs;
1181
1182 newargs = setup_root_args(data);
1183 if (!newargs)
1184 return ERR_PTR(-ENOMEM);
1185 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
1186 newargs);
1187 kfree(newargs);
1188 if (IS_ERR(mnt))
1189 return ERR_CAST(mnt);
1190
1191 root = mount_subtree(mnt, subvol_name);
1192
1193 if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
1194 struct super_block *s = root->d_sb;
1195 dput(root);
1196 root = ERR_PTR(-EINVAL);
1197 deactivate_locked_super(s);
1198 printk(KERN_ERR "BTRFS: '%s' is not a valid subvolume\n",
1199 subvol_name);
1200 }
1201
1202 return root;
1203 }
1204
1205 /*
1206 * Find a superblock for the given device / mount point.
1207 *
1208 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1209 * for multiple device setup. Make sure to keep it in sync.
1210 */
1211 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1212 const char *device_name, void *data)
1213 {
1214 struct block_device *bdev = NULL;
1215 struct super_block *s;
1216 struct dentry *root;
1217 struct btrfs_fs_devices *fs_devices = NULL;
1218 struct btrfs_fs_info *fs_info = NULL;
1219 fmode_t mode = FMODE_READ;
1220 char *subvol_name = NULL;
1221 u64 subvol_objectid = 0;
1222 int error = 0;
1223
1224 if (!(flags & MS_RDONLY))
1225 mode |= FMODE_WRITE;
1226
1227 error = btrfs_parse_early_options(data, mode, fs_type,
1228 &subvol_name, &subvol_objectid,
1229 &fs_devices);
1230 if (error) {
1231 kfree(subvol_name);
1232 return ERR_PTR(error);
1233 }
1234
1235 if (subvol_name) {
1236 root = mount_subvol(subvol_name, flags, device_name, data);
1237 kfree(subvol_name);
1238 return root;
1239 }
1240
1241 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1242 if (error)
1243 return ERR_PTR(error);
1244
1245 /*
1246 * Setup a dummy root and fs_info for test/set super. This is because
1247 * we don't actually fill this stuff out until open_ctree, but we need
1248 * it for searching for existing supers, so this lets us do that and
1249 * then open_ctree will properly initialize everything later.
1250 */
1251 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1252 if (!fs_info)
1253 return ERR_PTR(-ENOMEM);
1254
1255 fs_info->fs_devices = fs_devices;
1256
1257 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1258 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1259 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1260 error = -ENOMEM;
1261 goto error_fs_info;
1262 }
1263
1264 error = btrfs_open_devices(fs_devices, mode, fs_type);
1265 if (error)
1266 goto error_fs_info;
1267
1268 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1269 error = -EACCES;
1270 goto error_close_devices;
1271 }
1272
1273 bdev = fs_devices->latest_bdev;
1274 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1275 fs_info);
1276 if (IS_ERR(s)) {
1277 error = PTR_ERR(s);
1278 goto error_close_devices;
1279 }
1280
1281 if (s->s_root) {
1282 btrfs_close_devices(fs_devices);
1283 free_fs_info(fs_info);
1284 if ((flags ^ s->s_flags) & MS_RDONLY)
1285 error = -EBUSY;
1286 } else {
1287 char b[BDEVNAME_SIZE];
1288
1289 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1290 btrfs_sb(s)->bdev_holder = fs_type;
1291 error = btrfs_fill_super(s, fs_devices, data,
1292 flags & MS_SILENT ? 1 : 0);
1293 }
1294
1295 root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1296 if (IS_ERR(root))
1297 deactivate_locked_super(s);
1298
1299 return root;
1300
1301 error_close_devices:
1302 btrfs_close_devices(fs_devices);
1303 error_fs_info:
1304 free_fs_info(fs_info);
1305 return ERR_PTR(error);
1306 }
1307
1308 static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit)
1309 {
1310 spin_lock_irq(&workers->lock);
1311 workers->max_workers = new_limit;
1312 spin_unlock_irq(&workers->lock);
1313 }
1314
1315 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1316 int new_pool_size, int old_pool_size)
1317 {
1318 if (new_pool_size == old_pool_size)
1319 return;
1320
1321 fs_info->thread_pool_size = new_pool_size;
1322
1323 btrfs_info(fs_info, "resize thread pool %d -> %d",
1324 old_pool_size, new_pool_size);
1325
1326 btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size);
1327 btrfs_set_max_workers(&fs_info->workers, new_pool_size);
1328 btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size);
1329 btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size);
1330 btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size);
1331 btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
1332 btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size);
1333 btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size);
1334 btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size);
1335 btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size);
1336 btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size);
1337 btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size);
1338 btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size);
1339 btrfs_set_max_workers(&fs_info->scrub_wr_completion_workers,
1340 new_pool_size);
1341 }
1342
1343 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1344 {
1345 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1346 }
1347
1348 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1349 unsigned long old_opts, int flags)
1350 {
1351 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1352 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1353 (flags & MS_RDONLY))) {
1354 /* wait for any defraggers to finish */
1355 wait_event(fs_info->transaction_wait,
1356 (atomic_read(&fs_info->defrag_running) == 0));
1357 if (flags & MS_RDONLY)
1358 sync_filesystem(fs_info->sb);
1359 }
1360 }
1361
1362 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1363 unsigned long old_opts)
1364 {
1365 /*
1366 * We need cleanup all defragable inodes if the autodefragment is
1367 * close or the fs is R/O.
1368 */
1369 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1370 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1371 (fs_info->sb->s_flags & MS_RDONLY))) {
1372 btrfs_cleanup_defrag_inodes(fs_info);
1373 }
1374
1375 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1376 }
1377
1378 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1379 {
1380 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1381 struct btrfs_root *root = fs_info->tree_root;
1382 unsigned old_flags = sb->s_flags;
1383 unsigned long old_opts = fs_info->mount_opt;
1384 unsigned long old_compress_type = fs_info->compress_type;
1385 u64 old_max_inline = fs_info->max_inline;
1386 u64 old_alloc_start = fs_info->alloc_start;
1387 int old_thread_pool_size = fs_info->thread_pool_size;
1388 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1389 int ret;
1390
1391 btrfs_remount_prepare(fs_info);
1392
1393 ret = btrfs_parse_options(root, data);
1394 if (ret) {
1395 ret = -EINVAL;
1396 goto restore;
1397 }
1398
1399 btrfs_remount_begin(fs_info, old_opts, *flags);
1400 btrfs_resize_thread_pool(fs_info,
1401 fs_info->thread_pool_size, old_thread_pool_size);
1402
1403 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1404 goto out;
1405
1406 if (*flags & MS_RDONLY) {
1407 /*
1408 * this also happens on 'umount -rf' or on shutdown, when
1409 * the filesystem is busy.
1410 */
1411
1412 /* wait for the uuid_scan task to finish */
1413 down(&fs_info->uuid_tree_rescan_sem);
1414 /* avoid complains from lockdep et al. */
1415 up(&fs_info->uuid_tree_rescan_sem);
1416
1417 sb->s_flags |= MS_RDONLY;
1418
1419 btrfs_dev_replace_suspend_for_unmount(fs_info);
1420 btrfs_scrub_cancel(fs_info);
1421 btrfs_pause_balance(fs_info);
1422
1423 ret = btrfs_commit_super(root);
1424 if (ret)
1425 goto restore;
1426 } else {
1427 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
1428 btrfs_err(fs_info,
1429 "Remounting read-write after error is not allowed");
1430 ret = -EINVAL;
1431 goto restore;
1432 }
1433 if (fs_info->fs_devices->rw_devices == 0) {
1434 ret = -EACCES;
1435 goto restore;
1436 }
1437
1438 if (fs_info->fs_devices->missing_devices >
1439 fs_info->num_tolerated_disk_barrier_failures &&
1440 !(*flags & MS_RDONLY)) {
1441 btrfs_warn(fs_info,
1442 "too many missing devices, writeable remount is not allowed");
1443 ret = -EACCES;
1444 goto restore;
1445 }
1446
1447 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1448 ret = -EINVAL;
1449 goto restore;
1450 }
1451
1452 ret = btrfs_cleanup_fs_roots(fs_info);
1453 if (ret)
1454 goto restore;
1455
1456 /* recover relocation */
1457 ret = btrfs_recover_relocation(root);
1458 if (ret)
1459 goto restore;
1460
1461 ret = btrfs_resume_balance_async(fs_info);
1462 if (ret)
1463 goto restore;
1464
1465 ret = btrfs_resume_dev_replace_async(fs_info);
1466 if (ret) {
1467 btrfs_warn(fs_info, "failed to resume dev_replace");
1468 goto restore;
1469 }
1470
1471 if (!fs_info->uuid_root) {
1472 btrfs_info(fs_info, "creating UUID tree");
1473 ret = btrfs_create_uuid_tree(fs_info);
1474 if (ret) {
1475 btrfs_warn(fs_info, "failed to create the UUID tree %d", ret);
1476 goto restore;
1477 }
1478 }
1479 sb->s_flags &= ~MS_RDONLY;
1480 }
1481 out:
1482 btrfs_remount_cleanup(fs_info, old_opts);
1483 return 0;
1484
1485 restore:
1486 /* We've hit an error - don't reset MS_RDONLY */
1487 if (sb->s_flags & MS_RDONLY)
1488 old_flags |= MS_RDONLY;
1489 sb->s_flags = old_flags;
1490 fs_info->mount_opt = old_opts;
1491 fs_info->compress_type = old_compress_type;
1492 fs_info->max_inline = old_max_inline;
1493 mutex_lock(&fs_info->chunk_mutex);
1494 fs_info->alloc_start = old_alloc_start;
1495 mutex_unlock(&fs_info->chunk_mutex);
1496 btrfs_resize_thread_pool(fs_info,
1497 old_thread_pool_size, fs_info->thread_pool_size);
1498 fs_info->metadata_ratio = old_metadata_ratio;
1499 btrfs_remount_cleanup(fs_info, old_opts);
1500 return ret;
1501 }
1502
1503 /* Used to sort the devices by max_avail(descending sort) */
1504 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1505 const void *dev_info2)
1506 {
1507 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1508 ((struct btrfs_device_info *)dev_info2)->max_avail)
1509 return -1;
1510 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1511 ((struct btrfs_device_info *)dev_info2)->max_avail)
1512 return 1;
1513 else
1514 return 0;
1515 }
1516
1517 /*
1518 * sort the devices by max_avail, in which max free extent size of each device
1519 * is stored.(Descending Sort)
1520 */
1521 static inline void btrfs_descending_sort_devices(
1522 struct btrfs_device_info *devices,
1523 size_t nr_devices)
1524 {
1525 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1526 btrfs_cmp_device_free_bytes, NULL);
1527 }
1528
1529 /*
1530 * The helper to calc the free space on the devices that can be used to store
1531 * file data.
1532 */
1533 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1534 {
1535 struct btrfs_fs_info *fs_info = root->fs_info;
1536 struct btrfs_device_info *devices_info;
1537 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1538 struct btrfs_device *device;
1539 u64 skip_space;
1540 u64 type;
1541 u64 avail_space;
1542 u64 used_space;
1543 u64 min_stripe_size;
1544 int min_stripes = 1, num_stripes = 1;
1545 int i = 0, nr_devices;
1546 int ret;
1547
1548 nr_devices = fs_info->fs_devices->open_devices;
1549 BUG_ON(!nr_devices);
1550
1551 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1552 GFP_NOFS);
1553 if (!devices_info)
1554 return -ENOMEM;
1555
1556 /* calc min stripe number for data space alloction */
1557 type = btrfs_get_alloc_profile(root, 1);
1558 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1559 min_stripes = 2;
1560 num_stripes = nr_devices;
1561 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1562 min_stripes = 2;
1563 num_stripes = 2;
1564 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1565 min_stripes = 4;
1566 num_stripes = 4;
1567 }
1568
1569 if (type & BTRFS_BLOCK_GROUP_DUP)
1570 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1571 else
1572 min_stripe_size = BTRFS_STRIPE_LEN;
1573
1574 list_for_each_entry(device, &fs_devices->devices, dev_list) {
1575 if (!device->in_fs_metadata || !device->bdev ||
1576 device->is_tgtdev_for_dev_replace)
1577 continue;
1578
1579 avail_space = device->total_bytes - device->bytes_used;
1580
1581 /* align with stripe_len */
1582 do_div(avail_space, BTRFS_STRIPE_LEN);
1583 avail_space *= BTRFS_STRIPE_LEN;
1584
1585 /*
1586 * In order to avoid overwritting the superblock on the drive,
1587 * btrfs starts at an offset of at least 1MB when doing chunk
1588 * allocation.
1589 */
1590 skip_space = 1024 * 1024;
1591
1592 /* user can set the offset in fs_info->alloc_start. */
1593 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1594 device->total_bytes)
1595 skip_space = max(fs_info->alloc_start, skip_space);
1596
1597 /*
1598 * btrfs can not use the free space in [0, skip_space - 1],
1599 * we must subtract it from the total. In order to implement
1600 * it, we account the used space in this range first.
1601 */
1602 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1603 &used_space);
1604 if (ret) {
1605 kfree(devices_info);
1606 return ret;
1607 }
1608
1609 /* calc the free space in [0, skip_space - 1] */
1610 skip_space -= used_space;
1611
1612 /*
1613 * we can use the free space in [0, skip_space - 1], subtract
1614 * it from the total.
1615 */
1616 if (avail_space && avail_space >= skip_space)
1617 avail_space -= skip_space;
1618 else
1619 avail_space = 0;
1620
1621 if (avail_space < min_stripe_size)
1622 continue;
1623
1624 devices_info[i].dev = device;
1625 devices_info[i].max_avail = avail_space;
1626
1627 i++;
1628 }
1629
1630 nr_devices = i;
1631
1632 btrfs_descending_sort_devices(devices_info, nr_devices);
1633
1634 i = nr_devices - 1;
1635 avail_space = 0;
1636 while (nr_devices >= min_stripes) {
1637 if (num_stripes > nr_devices)
1638 num_stripes = nr_devices;
1639
1640 if (devices_info[i].max_avail >= min_stripe_size) {
1641 int j;
1642 u64 alloc_size;
1643
1644 avail_space += devices_info[i].max_avail * num_stripes;
1645 alloc_size = devices_info[i].max_avail;
1646 for (j = i + 1 - num_stripes; j <= i; j++)
1647 devices_info[j].max_avail -= alloc_size;
1648 }
1649 i--;
1650 nr_devices--;
1651 }
1652
1653 kfree(devices_info);
1654 *free_bytes = avail_space;
1655 return 0;
1656 }
1657
1658 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1659 {
1660 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1661 struct btrfs_super_block *disk_super = fs_info->super_copy;
1662 struct list_head *head = &fs_info->space_info;
1663 struct btrfs_space_info *found;
1664 u64 total_used = 0;
1665 u64 total_free_data = 0;
1666 int bits = dentry->d_sb->s_blocksize_bits;
1667 __be32 *fsid = (__be32 *)fs_info->fsid;
1668 int ret;
1669
1670 /* holding chunk_muext to avoid allocating new chunks */
1671 mutex_lock(&fs_info->chunk_mutex);
1672 rcu_read_lock();
1673 list_for_each_entry_rcu(found, head, list) {
1674 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1675 total_free_data += found->disk_total - found->disk_used;
1676 total_free_data -=
1677 btrfs_account_ro_block_groups_free_space(found);
1678 }
1679
1680 total_used += found->disk_used;
1681 }
1682 rcu_read_unlock();
1683
1684 buf->f_namelen = BTRFS_NAME_LEN;
1685 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1686 buf->f_bfree = buf->f_blocks - (total_used >> bits);
1687 buf->f_bsize = dentry->d_sb->s_blocksize;
1688 buf->f_type = BTRFS_SUPER_MAGIC;
1689 buf->f_bavail = total_free_data;
1690 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1691 if (ret) {
1692 mutex_unlock(&fs_info->chunk_mutex);
1693 return ret;
1694 }
1695 buf->f_bavail += total_free_data;
1696 buf->f_bavail = buf->f_bavail >> bits;
1697 mutex_unlock(&fs_info->chunk_mutex);
1698
1699 /* We treat it as constant endianness (it doesn't matter _which_)
1700 because we want the fsid to come out the same whether mounted
1701 on a big-endian or little-endian host */
1702 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1703 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1704 /* Mask in the root object ID too, to disambiguate subvols */
1705 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1706 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1707
1708 return 0;
1709 }
1710
1711 static void btrfs_kill_super(struct super_block *sb)
1712 {
1713 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1714 kill_anon_super(sb);
1715 free_fs_info(fs_info);
1716 }
1717
1718 static struct file_system_type btrfs_fs_type = {
1719 .owner = THIS_MODULE,
1720 .name = "btrfs",
1721 .mount = btrfs_mount,
1722 .kill_sb = btrfs_kill_super,
1723 .fs_flags = FS_REQUIRES_DEV,
1724 };
1725 MODULE_ALIAS_FS("btrfs");
1726
1727 /*
1728 * used by btrfsctl to scan devices when no FS is mounted
1729 */
1730 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1731 unsigned long arg)
1732 {
1733 struct btrfs_ioctl_vol_args *vol;
1734 struct btrfs_fs_devices *fs_devices;
1735 int ret = -ENOTTY;
1736
1737 if (!capable(CAP_SYS_ADMIN))
1738 return -EPERM;
1739
1740 vol = memdup_user((void __user *)arg, sizeof(*vol));
1741 if (IS_ERR(vol))
1742 return PTR_ERR(vol);
1743
1744 switch (cmd) {
1745 case BTRFS_IOC_SCAN_DEV:
1746 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1747 &btrfs_fs_type, &fs_devices);
1748 break;
1749 case BTRFS_IOC_DEVICES_READY:
1750 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1751 &btrfs_fs_type, &fs_devices);
1752 if (ret)
1753 break;
1754 ret = !(fs_devices->num_devices == fs_devices->total_devices);
1755 break;
1756 }
1757
1758 kfree(vol);
1759 return ret;
1760 }
1761
1762 static int btrfs_freeze(struct super_block *sb)
1763 {
1764 struct btrfs_trans_handle *trans;
1765 struct btrfs_root *root = btrfs_sb(sb)->tree_root;
1766
1767 trans = btrfs_attach_transaction_barrier(root);
1768 if (IS_ERR(trans)) {
1769 /* no transaction, don't bother */
1770 if (PTR_ERR(trans) == -ENOENT)
1771 return 0;
1772 return PTR_ERR(trans);
1773 }
1774 return btrfs_commit_transaction(trans, root);
1775 }
1776
1777 static int btrfs_unfreeze(struct super_block *sb)
1778 {
1779 return 0;
1780 }
1781
1782 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1783 {
1784 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1785 struct btrfs_fs_devices *cur_devices;
1786 struct btrfs_device *dev, *first_dev = NULL;
1787 struct list_head *head;
1788 struct rcu_string *name;
1789
1790 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1791 cur_devices = fs_info->fs_devices;
1792 while (cur_devices) {
1793 head = &cur_devices->devices;
1794 list_for_each_entry(dev, head, dev_list) {
1795 if (dev->missing)
1796 continue;
1797 if (!first_dev || dev->devid < first_dev->devid)
1798 first_dev = dev;
1799 }
1800 cur_devices = cur_devices->seed;
1801 }
1802
1803 if (first_dev) {
1804 rcu_read_lock();
1805 name = rcu_dereference(first_dev->name);
1806 seq_escape(m, name->str, " \t\n\\");
1807 rcu_read_unlock();
1808 } else {
1809 WARN_ON(1);
1810 }
1811 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1812 return 0;
1813 }
1814
1815 static const struct super_operations btrfs_super_ops = {
1816 .drop_inode = btrfs_drop_inode,
1817 .evict_inode = btrfs_evict_inode,
1818 .put_super = btrfs_put_super,
1819 .sync_fs = btrfs_sync_fs,
1820 .show_options = btrfs_show_options,
1821 .show_devname = btrfs_show_devname,
1822 .write_inode = btrfs_write_inode,
1823 .alloc_inode = btrfs_alloc_inode,
1824 .destroy_inode = btrfs_destroy_inode,
1825 .statfs = btrfs_statfs,
1826 .remount_fs = btrfs_remount,
1827 .freeze_fs = btrfs_freeze,
1828 .unfreeze_fs = btrfs_unfreeze,
1829 };
1830
1831 static const struct file_operations btrfs_ctl_fops = {
1832 .unlocked_ioctl = btrfs_control_ioctl,
1833 .compat_ioctl = btrfs_control_ioctl,
1834 .owner = THIS_MODULE,
1835 .llseek = noop_llseek,
1836 };
1837
1838 static struct miscdevice btrfs_misc = {
1839 .minor = BTRFS_MINOR,
1840 .name = "btrfs-control",
1841 .fops = &btrfs_ctl_fops
1842 };
1843
1844 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1845 MODULE_ALIAS("devname:btrfs-control");
1846
1847 static int btrfs_interface_init(void)
1848 {
1849 return misc_register(&btrfs_misc);
1850 }
1851
1852 static void btrfs_interface_exit(void)
1853 {
1854 if (misc_deregister(&btrfs_misc) < 0)
1855 printk(KERN_INFO "BTRFS: misc_deregister failed for control device\n");
1856 }
1857
1858 static void btrfs_print_info(void)
1859 {
1860 printk(KERN_INFO "Btrfs loaded"
1861 #ifdef CONFIG_BTRFS_DEBUG
1862 ", debug=on"
1863 #endif
1864 #ifdef CONFIG_BTRFS_ASSERT
1865 ", assert=on"
1866 #endif
1867 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1868 ", integrity-checker=on"
1869 #endif
1870 "\n");
1871 }
1872
1873 static int btrfs_run_sanity_tests(void)
1874 {
1875 int ret;
1876
1877 ret = btrfs_init_test_fs();
1878 if (ret)
1879 return ret;
1880
1881 ret = btrfs_test_free_space_cache();
1882 if (ret)
1883 goto out;
1884 ret = btrfs_test_extent_buffer_operations();
1885 if (ret)
1886 goto out;
1887 ret = btrfs_test_extent_io();
1888 if (ret)
1889 goto out;
1890 ret = btrfs_test_inodes();
1891 out:
1892 btrfs_destroy_test_fs();
1893 return ret;
1894 }
1895
1896 static int __init init_btrfs_fs(void)
1897 {
1898 int err;
1899
1900 err = btrfs_hash_init();
1901 if (err)
1902 return err;
1903
1904 btrfs_props_init();
1905
1906 err = btrfs_init_sysfs();
1907 if (err)
1908 goto free_hash;
1909
1910 btrfs_init_compress();
1911
1912 err = btrfs_init_cachep();
1913 if (err)
1914 goto free_compress;
1915
1916 err = extent_io_init();
1917 if (err)
1918 goto free_cachep;
1919
1920 err = extent_map_init();
1921 if (err)
1922 goto free_extent_io;
1923
1924 err = ordered_data_init();
1925 if (err)
1926 goto free_extent_map;
1927
1928 err = btrfs_delayed_inode_init();
1929 if (err)
1930 goto free_ordered_data;
1931
1932 err = btrfs_auto_defrag_init();
1933 if (err)
1934 goto free_delayed_inode;
1935
1936 err = btrfs_delayed_ref_init();
1937 if (err)
1938 goto free_auto_defrag;
1939
1940 err = btrfs_prelim_ref_init();
1941 if (err)
1942 goto free_prelim_ref;
1943
1944 err = btrfs_interface_init();
1945 if (err)
1946 goto free_delayed_ref;
1947
1948 btrfs_init_lockdep();
1949
1950 btrfs_print_info();
1951
1952 err = btrfs_run_sanity_tests();
1953 if (err)
1954 goto unregister_ioctl;
1955
1956 err = register_filesystem(&btrfs_fs_type);
1957 if (err)
1958 goto unregister_ioctl;
1959
1960 return 0;
1961
1962 unregister_ioctl:
1963 btrfs_interface_exit();
1964 free_prelim_ref:
1965 btrfs_prelim_ref_exit();
1966 free_delayed_ref:
1967 btrfs_delayed_ref_exit();
1968 free_auto_defrag:
1969 btrfs_auto_defrag_exit();
1970 free_delayed_inode:
1971 btrfs_delayed_inode_exit();
1972 free_ordered_data:
1973 ordered_data_exit();
1974 free_extent_map:
1975 extent_map_exit();
1976 free_extent_io:
1977 extent_io_exit();
1978 free_cachep:
1979 btrfs_destroy_cachep();
1980 free_compress:
1981 btrfs_exit_compress();
1982 btrfs_exit_sysfs();
1983 free_hash:
1984 btrfs_hash_exit();
1985 return err;
1986 }
1987
1988 static void __exit exit_btrfs_fs(void)
1989 {
1990 btrfs_destroy_cachep();
1991 btrfs_delayed_ref_exit();
1992 btrfs_auto_defrag_exit();
1993 btrfs_delayed_inode_exit();
1994 btrfs_prelim_ref_exit();
1995 ordered_data_exit();
1996 extent_map_exit();
1997 extent_io_exit();
1998 btrfs_interface_exit();
1999 unregister_filesystem(&btrfs_fs_type);
2000 btrfs_exit_sysfs();
2001 btrfs_cleanup_fs_uuids();
2002 btrfs_exit_compress();
2003 btrfs_hash_exit();
2004 }
2005
2006 late_initcall(init_btrfs_fs);
2007 module_exit(exit_btrfs_fs)
2008
2009 MODULE_LICENSE("GPL");
Linux with added FPC-III support