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Btrfs: clean up error handling in mount_subvol()
[deliverable/linux.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 <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 #include "qgroup.h"
64 #define CREATE_TRACE_POINTS
65 #include <trace/events/btrfs.h>
66
67 static const struct super_operations btrfs_super_ops;
68 static struct file_system_type btrfs_fs_type;
69
70 static int btrfs_remount(struct super_block *sb, int *flags, char *data);
71
72 static const char *btrfs_decode_error(int errno)
73 {
74 char *errstr = "unknown";
75
76 switch (errno) {
77 case -EIO:
78 errstr = "IO failure";
79 break;
80 case -ENOMEM:
81 errstr = "Out of memory";
82 break;
83 case -EROFS:
84 errstr = "Readonly filesystem";
85 break;
86 case -EEXIST:
87 errstr = "Object already exists";
88 break;
89 case -ENOSPC:
90 errstr = "No space left";
91 break;
92 case -ENOENT:
93 errstr = "No such entry";
94 break;
95 }
96
97 return errstr;
98 }
99
100 static void save_error_info(struct btrfs_fs_info *fs_info)
101 {
102 /*
103 * today we only save the error info into ram. Long term we'll
104 * also send it down to the disk
105 */
106 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
107 }
108
109 /* btrfs handle error by forcing the filesystem readonly */
110 static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
111 {
112 struct super_block *sb = fs_info->sb;
113
114 if (sb->s_flags & MS_RDONLY)
115 return;
116
117 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
118 sb->s_flags |= MS_RDONLY;
119 btrfs_info(fs_info, "forced readonly");
120 /*
121 * Note that a running device replace operation is not
122 * canceled here although there is no way to update
123 * the progress. It would add the risk of a deadlock,
124 * therefore the canceling is ommited. The only penalty
125 * is that some I/O remains active until the procedure
126 * completes. The next time when the filesystem is
127 * mounted writeable again, the device replace
128 * operation continues.
129 */
130 }
131 }
132
133 #ifdef CONFIG_PRINTK
134 /*
135 * __btrfs_std_error decodes expected errors from the caller and
136 * invokes the approciate error response.
137 */
138 __cold
139 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
140 unsigned int line, int errno, const char *fmt, ...)
141 {
142 struct super_block *sb = fs_info->sb;
143 const char *errstr;
144
145 /*
146 * Special case: if the error is EROFS, and we're already
147 * under MS_RDONLY, then it is safe here.
148 */
149 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
150 return;
151
152 errstr = btrfs_decode_error(errno);
153 if (fmt) {
154 struct va_format vaf;
155 va_list args;
156
157 va_start(args, fmt);
158 vaf.fmt = fmt;
159 vaf.va = &args;
160
161 printk(KERN_CRIT
162 "BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
163 sb->s_id, function, line, errno, errstr, &vaf);
164 va_end(args);
165 } else {
166 printk(KERN_CRIT "BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
167 sb->s_id, function, line, errno, errstr);
168 }
169
170 /* Don't go through full error handling during mount */
171 save_error_info(fs_info);
172 if (sb->s_flags & MS_BORN)
173 btrfs_handle_error(fs_info);
174 }
175
176 static const char * const logtypes[] = {
177 "emergency",
178 "alert",
179 "critical",
180 "error",
181 "warning",
182 "notice",
183 "info",
184 "debug",
185 };
186
187 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
188 {
189 struct super_block *sb = fs_info->sb;
190 char lvl[4];
191 struct va_format vaf;
192 va_list args;
193 const char *type = logtypes[4];
194 int kern_level;
195
196 va_start(args, fmt);
197
198 kern_level = printk_get_level(fmt);
199 if (kern_level) {
200 size_t size = printk_skip_level(fmt) - fmt;
201 memcpy(lvl, fmt, size);
202 lvl[size] = '\0';
203 fmt += size;
204 type = logtypes[kern_level - '0'];
205 } else
206 *lvl = '\0';
207
208 vaf.fmt = fmt;
209 vaf.va = &args;
210
211 printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
212
213 va_end(args);
214 }
215
216 #else
217
218 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
219 unsigned int line, int errno, const char *fmt, ...)
220 {
221 struct super_block *sb = fs_info->sb;
222
223 /*
224 * Special case: if the error is EROFS, and we're already
225 * under MS_RDONLY, then it is safe here.
226 */
227 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
228 return;
229
230 /* Don't go through full error handling during mount */
231 if (sb->s_flags & MS_BORN) {
232 save_error_info(fs_info);
233 btrfs_handle_error(fs_info);
234 }
235 }
236 #endif
237
238 /*
239 * We only mark the transaction aborted and then set the file system read-only.
240 * This will prevent new transactions from starting or trying to join this
241 * one.
242 *
243 * This means that error recovery at the call site is limited to freeing
244 * any local memory allocations and passing the error code up without
245 * further cleanup. The transaction should complete as it normally would
246 * in the call path but will return -EIO.
247 *
248 * We'll complete the cleanup in btrfs_end_transaction and
249 * btrfs_commit_transaction.
250 */
251 __cold
252 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
253 struct btrfs_root *root, const char *function,
254 unsigned int line, int errno)
255 {
256 trans->aborted = errno;
257 /* Nothing used. The other threads that have joined this
258 * transaction may be able to continue. */
259 if (!trans->blocks_used && list_empty(&trans->new_bgs)) {
260 const char *errstr;
261
262 errstr = btrfs_decode_error(errno);
263 btrfs_warn(root->fs_info,
264 "%s:%d: Aborting unused transaction(%s).",
265 function, line, errstr);
266 return;
267 }
268 ACCESS_ONCE(trans->transaction->aborted) = errno;
269 /* Wake up anybody who may be waiting on this transaction */
270 wake_up(&root->fs_info->transaction_wait);
271 wake_up(&root->fs_info->transaction_blocked_wait);
272 __btrfs_std_error(root->fs_info, function, line, errno, NULL);
273 }
274 /*
275 * __btrfs_panic decodes unexpected, fatal errors from the caller,
276 * issues an alert, and either panics or BUGs, depending on mount options.
277 */
278 __cold
279 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
280 unsigned int line, int errno, const char *fmt, ...)
281 {
282 char *s_id = "<unknown>";
283 const char *errstr;
284 struct va_format vaf = { .fmt = fmt };
285 va_list args;
286
287 if (fs_info)
288 s_id = fs_info->sb->s_id;
289
290 va_start(args, fmt);
291 vaf.va = &args;
292
293 errstr = btrfs_decode_error(errno);
294 if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
295 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
296 s_id, function, line, &vaf, errno, errstr);
297
298 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
299 function, line, &vaf, errno, errstr);
300 va_end(args);
301 /* Caller calls BUG() */
302 }
303
304 static void btrfs_put_super(struct super_block *sb)
305 {
306 close_ctree(btrfs_sb(sb)->tree_root);
307 }
308
309 enum {
310 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
311 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
312 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
313 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
314 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
315 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
316 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
317 Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
318 Opt_check_integrity, Opt_check_integrity_including_extent_data,
319 Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree,
320 Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard,
321 Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow,
322 Opt_datasum, Opt_treelog, Opt_noinode_cache,
323 Opt_err,
324 };
325
326 static match_table_t tokens = {
327 {Opt_degraded, "degraded"},
328 {Opt_subvol, "subvol=%s"},
329 {Opt_subvolid, "subvolid=%s"},
330 {Opt_device, "device=%s"},
331 {Opt_nodatasum, "nodatasum"},
332 {Opt_datasum, "datasum"},
333 {Opt_nodatacow, "nodatacow"},
334 {Opt_datacow, "datacow"},
335 {Opt_nobarrier, "nobarrier"},
336 {Opt_barrier, "barrier"},
337 {Opt_max_inline, "max_inline=%s"},
338 {Opt_alloc_start, "alloc_start=%s"},
339 {Opt_thread_pool, "thread_pool=%d"},
340 {Opt_compress, "compress"},
341 {Opt_compress_type, "compress=%s"},
342 {Opt_compress_force, "compress-force"},
343 {Opt_compress_force_type, "compress-force=%s"},
344 {Opt_ssd, "ssd"},
345 {Opt_ssd_spread, "ssd_spread"},
346 {Opt_nossd, "nossd"},
347 {Opt_acl, "acl"},
348 {Opt_noacl, "noacl"},
349 {Opt_notreelog, "notreelog"},
350 {Opt_treelog, "treelog"},
351 {Opt_flushoncommit, "flushoncommit"},
352 {Opt_noflushoncommit, "noflushoncommit"},
353 {Opt_ratio, "metadata_ratio=%d"},
354 {Opt_discard, "discard"},
355 {Opt_nodiscard, "nodiscard"},
356 {Opt_space_cache, "space_cache"},
357 {Opt_clear_cache, "clear_cache"},
358 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
359 {Opt_enospc_debug, "enospc_debug"},
360 {Opt_noenospc_debug, "noenospc_debug"},
361 {Opt_subvolrootid, "subvolrootid=%d"},
362 {Opt_defrag, "autodefrag"},
363 {Opt_nodefrag, "noautodefrag"},
364 {Opt_inode_cache, "inode_cache"},
365 {Opt_noinode_cache, "noinode_cache"},
366 {Opt_no_space_cache, "nospace_cache"},
367 {Opt_recovery, "recovery"},
368 {Opt_skip_balance, "skip_balance"},
369 {Opt_check_integrity, "check_int"},
370 {Opt_check_integrity_including_extent_data, "check_int_data"},
371 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
372 {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
373 {Opt_fatal_errors, "fatal_errors=%s"},
374 {Opt_commit_interval, "commit=%d"},
375 {Opt_err, NULL},
376 };
377
378 /*
379 * Regular mount options parser. Everything that is needed only when
380 * reading in a new superblock is parsed here.
381 * XXX JDM: This needs to be cleaned up for remount.
382 */
383 int btrfs_parse_options(struct btrfs_root *root, char *options)
384 {
385 struct btrfs_fs_info *info = root->fs_info;
386 substring_t args[MAX_OPT_ARGS];
387 char *p, *num, *orig = NULL;
388 u64 cache_gen;
389 int intarg;
390 int ret = 0;
391 char *compress_type;
392 bool compress_force = false;
393
394 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
395 if (cache_gen)
396 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
397
398 if (!options)
399 goto out;
400
401 /*
402 * strsep changes the string, duplicate it because parse_options
403 * gets called twice
404 */
405 options = kstrdup(options, GFP_NOFS);
406 if (!options)
407 return -ENOMEM;
408
409 orig = options;
410
411 while ((p = strsep(&options, ",")) != NULL) {
412 int token;
413 if (!*p)
414 continue;
415
416 token = match_token(p, tokens, args);
417 switch (token) {
418 case Opt_degraded:
419 btrfs_info(root->fs_info, "allowing degraded mounts");
420 btrfs_set_opt(info->mount_opt, DEGRADED);
421 break;
422 case Opt_subvol:
423 case Opt_subvolid:
424 case Opt_subvolrootid:
425 case Opt_device:
426 /*
427 * These are parsed by btrfs_parse_early_options
428 * and can be happily ignored here.
429 */
430 break;
431 case Opt_nodatasum:
432 btrfs_set_and_info(root, NODATASUM,
433 "setting nodatasum");
434 break;
435 case Opt_datasum:
436 if (btrfs_test_opt(root, NODATASUM)) {
437 if (btrfs_test_opt(root, NODATACOW))
438 btrfs_info(root->fs_info, "setting datasum, datacow enabled");
439 else
440 btrfs_info(root->fs_info, "setting datasum");
441 }
442 btrfs_clear_opt(info->mount_opt, NODATACOW);
443 btrfs_clear_opt(info->mount_opt, NODATASUM);
444 break;
445 case Opt_nodatacow:
446 if (!btrfs_test_opt(root, NODATACOW)) {
447 if (!btrfs_test_opt(root, COMPRESS) ||
448 !btrfs_test_opt(root, FORCE_COMPRESS)) {
449 btrfs_info(root->fs_info,
450 "setting nodatacow, compression disabled");
451 } else {
452 btrfs_info(root->fs_info, "setting nodatacow");
453 }
454 }
455 btrfs_clear_opt(info->mount_opt, COMPRESS);
456 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
457 btrfs_set_opt(info->mount_opt, NODATACOW);
458 btrfs_set_opt(info->mount_opt, NODATASUM);
459 break;
460 case Opt_datacow:
461 btrfs_clear_and_info(root, NODATACOW,
462 "setting datacow");
463 break;
464 case Opt_compress_force:
465 case Opt_compress_force_type:
466 compress_force = true;
467 /* Fallthrough */
468 case Opt_compress:
469 case Opt_compress_type:
470 if (token == Opt_compress ||
471 token == Opt_compress_force ||
472 strcmp(args[0].from, "zlib") == 0) {
473 compress_type = "zlib";
474 info->compress_type = BTRFS_COMPRESS_ZLIB;
475 btrfs_set_opt(info->mount_opt, COMPRESS);
476 btrfs_clear_opt(info->mount_opt, NODATACOW);
477 btrfs_clear_opt(info->mount_opt, NODATASUM);
478 } else if (strcmp(args[0].from, "lzo") == 0) {
479 compress_type = "lzo";
480 info->compress_type = BTRFS_COMPRESS_LZO;
481 btrfs_set_opt(info->mount_opt, COMPRESS);
482 btrfs_clear_opt(info->mount_opt, NODATACOW);
483 btrfs_clear_opt(info->mount_opt, NODATASUM);
484 btrfs_set_fs_incompat(info, COMPRESS_LZO);
485 } else if (strncmp(args[0].from, "no", 2) == 0) {
486 compress_type = "no";
487 btrfs_clear_opt(info->mount_opt, COMPRESS);
488 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
489 compress_force = false;
490 } else {
491 ret = -EINVAL;
492 goto out;
493 }
494
495 if (compress_force) {
496 btrfs_set_and_info(root, FORCE_COMPRESS,
497 "force %s compression",
498 compress_type);
499 } else {
500 if (!btrfs_test_opt(root, COMPRESS))
501 btrfs_info(root->fs_info,
502 "btrfs: use %s compression",
503 compress_type);
504 /*
505 * If we remount from compress-force=xxx to
506 * compress=xxx, we need clear FORCE_COMPRESS
507 * flag, otherwise, there is no way for users
508 * to disable forcible compression separately.
509 */
510 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
511 }
512 break;
513 case Opt_ssd:
514 btrfs_set_and_info(root, SSD,
515 "use ssd allocation scheme");
516 break;
517 case Opt_ssd_spread:
518 btrfs_set_and_info(root, SSD_SPREAD,
519 "use spread ssd allocation scheme");
520 btrfs_set_opt(info->mount_opt, SSD);
521 break;
522 case Opt_nossd:
523 btrfs_set_and_info(root, NOSSD,
524 "not using ssd allocation scheme");
525 btrfs_clear_opt(info->mount_opt, SSD);
526 break;
527 case Opt_barrier:
528 btrfs_clear_and_info(root, NOBARRIER,
529 "turning on barriers");
530 break;
531 case Opt_nobarrier:
532 btrfs_set_and_info(root, NOBARRIER,
533 "turning off barriers");
534 break;
535 case Opt_thread_pool:
536 ret = match_int(&args[0], &intarg);
537 if (ret) {
538 goto out;
539 } else if (intarg > 0) {
540 info->thread_pool_size = intarg;
541 } else {
542 ret = -EINVAL;
543 goto out;
544 }
545 break;
546 case Opt_max_inline:
547 num = match_strdup(&args[0]);
548 if (num) {
549 info->max_inline = memparse(num, NULL);
550 kfree(num);
551
552 if (info->max_inline) {
553 info->max_inline = min_t(u64,
554 info->max_inline,
555 root->sectorsize);
556 }
557 btrfs_info(root->fs_info, "max_inline at %llu",
558 info->max_inline);
559 } else {
560 ret = -ENOMEM;
561 goto out;
562 }
563 break;
564 case Opt_alloc_start:
565 num = match_strdup(&args[0]);
566 if (num) {
567 mutex_lock(&info->chunk_mutex);
568 info->alloc_start = memparse(num, NULL);
569 mutex_unlock(&info->chunk_mutex);
570 kfree(num);
571 btrfs_info(root->fs_info, "allocations start at %llu",
572 info->alloc_start);
573 } else {
574 ret = -ENOMEM;
575 goto out;
576 }
577 break;
578 case Opt_acl:
579 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
580 root->fs_info->sb->s_flags |= MS_POSIXACL;
581 break;
582 #else
583 btrfs_err(root->fs_info,
584 "support for ACL not compiled in!");
585 ret = -EINVAL;
586 goto out;
587 #endif
588 case Opt_noacl:
589 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
590 break;
591 case Opt_notreelog:
592 btrfs_set_and_info(root, NOTREELOG,
593 "disabling tree log");
594 break;
595 case Opt_treelog:
596 btrfs_clear_and_info(root, NOTREELOG,
597 "enabling tree log");
598 break;
599 case Opt_flushoncommit:
600 btrfs_set_and_info(root, FLUSHONCOMMIT,
601 "turning on flush-on-commit");
602 break;
603 case Opt_noflushoncommit:
604 btrfs_clear_and_info(root, FLUSHONCOMMIT,
605 "turning off flush-on-commit");
606 break;
607 case Opt_ratio:
608 ret = match_int(&args[0], &intarg);
609 if (ret) {
610 goto out;
611 } else if (intarg >= 0) {
612 info->metadata_ratio = intarg;
613 btrfs_info(root->fs_info, "metadata ratio %d",
614 info->metadata_ratio);
615 } else {
616 ret = -EINVAL;
617 goto out;
618 }
619 break;
620 case Opt_discard:
621 btrfs_set_and_info(root, DISCARD,
622 "turning on discard");
623 break;
624 case Opt_nodiscard:
625 btrfs_clear_and_info(root, DISCARD,
626 "turning off discard");
627 break;
628 case Opt_space_cache:
629 btrfs_set_and_info(root, SPACE_CACHE,
630 "enabling disk space caching");
631 break;
632 case Opt_rescan_uuid_tree:
633 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
634 break;
635 case Opt_no_space_cache:
636 btrfs_clear_and_info(root, SPACE_CACHE,
637 "disabling disk space caching");
638 break;
639 case Opt_inode_cache:
640 btrfs_set_pending_and_info(info, INODE_MAP_CACHE,
641 "enabling inode map caching");
642 break;
643 case Opt_noinode_cache:
644 btrfs_clear_pending_and_info(info, INODE_MAP_CACHE,
645 "disabling inode map caching");
646 break;
647 case Opt_clear_cache:
648 btrfs_set_and_info(root, CLEAR_CACHE,
649 "force clearing of disk cache");
650 break;
651 case Opt_user_subvol_rm_allowed:
652 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
653 break;
654 case Opt_enospc_debug:
655 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
656 break;
657 case Opt_noenospc_debug:
658 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
659 break;
660 case Opt_defrag:
661 btrfs_set_and_info(root, AUTO_DEFRAG,
662 "enabling auto defrag");
663 break;
664 case Opt_nodefrag:
665 btrfs_clear_and_info(root, AUTO_DEFRAG,
666 "disabling auto defrag");
667 break;
668 case Opt_recovery:
669 btrfs_info(root->fs_info, "enabling auto recovery");
670 btrfs_set_opt(info->mount_opt, RECOVERY);
671 break;
672 case Opt_skip_balance:
673 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
674 break;
675 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
676 case Opt_check_integrity_including_extent_data:
677 btrfs_info(root->fs_info,
678 "enabling check integrity including extent data");
679 btrfs_set_opt(info->mount_opt,
680 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
681 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
682 break;
683 case Opt_check_integrity:
684 btrfs_info(root->fs_info, "enabling check integrity");
685 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
686 break;
687 case Opt_check_integrity_print_mask:
688 ret = match_int(&args[0], &intarg);
689 if (ret) {
690 goto out;
691 } else if (intarg >= 0) {
692 info->check_integrity_print_mask = intarg;
693 btrfs_info(root->fs_info, "check_integrity_print_mask 0x%x",
694 info->check_integrity_print_mask);
695 } else {
696 ret = -EINVAL;
697 goto out;
698 }
699 break;
700 #else
701 case Opt_check_integrity_including_extent_data:
702 case Opt_check_integrity:
703 case Opt_check_integrity_print_mask:
704 btrfs_err(root->fs_info,
705 "support for check_integrity* not compiled in!");
706 ret = -EINVAL;
707 goto out;
708 #endif
709 case Opt_fatal_errors:
710 if (strcmp(args[0].from, "panic") == 0)
711 btrfs_set_opt(info->mount_opt,
712 PANIC_ON_FATAL_ERROR);
713 else if (strcmp(args[0].from, "bug") == 0)
714 btrfs_clear_opt(info->mount_opt,
715 PANIC_ON_FATAL_ERROR);
716 else {
717 ret = -EINVAL;
718 goto out;
719 }
720 break;
721 case Opt_commit_interval:
722 intarg = 0;
723 ret = match_int(&args[0], &intarg);
724 if (ret < 0) {
725 btrfs_err(root->fs_info, "invalid commit interval");
726 ret = -EINVAL;
727 goto out;
728 }
729 if (intarg > 0) {
730 if (intarg > 300) {
731 btrfs_warn(root->fs_info, "excessive commit interval %d",
732 intarg);
733 }
734 info->commit_interval = intarg;
735 } else {
736 btrfs_info(root->fs_info, "using default commit interval %ds",
737 BTRFS_DEFAULT_COMMIT_INTERVAL);
738 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
739 }
740 break;
741 case Opt_err:
742 btrfs_info(root->fs_info, "unrecognized mount option '%s'", p);
743 ret = -EINVAL;
744 goto out;
745 default:
746 break;
747 }
748 }
749 out:
750 if (!ret && btrfs_test_opt(root, SPACE_CACHE))
751 btrfs_info(root->fs_info, "disk space caching is enabled");
752 kfree(orig);
753 return ret;
754 }
755
756 /*
757 * Parse mount options that are required early in the mount process.
758 *
759 * All other options will be parsed on much later in the mount process and
760 * only when we need to allocate a new super block.
761 */
762 static int btrfs_parse_early_options(const char *options, fmode_t flags,
763 void *holder, char **subvol_name, u64 *subvol_objectid,
764 struct btrfs_fs_devices **fs_devices)
765 {
766 substring_t args[MAX_OPT_ARGS];
767 char *device_name, *opts, *orig, *p;
768 char *num = NULL;
769 int error = 0;
770
771 if (!options)
772 return 0;
773
774 /*
775 * strsep changes the string, duplicate it because parse_options
776 * gets called twice
777 */
778 opts = kstrdup(options, GFP_KERNEL);
779 if (!opts)
780 return -ENOMEM;
781 orig = opts;
782
783 while ((p = strsep(&opts, ",")) != NULL) {
784 int token;
785 if (!*p)
786 continue;
787
788 token = match_token(p, tokens, args);
789 switch (token) {
790 case Opt_subvol:
791 kfree(*subvol_name);
792 *subvol_name = match_strdup(&args[0]);
793 if (!*subvol_name) {
794 error = -ENOMEM;
795 goto out;
796 }
797 break;
798 case Opt_subvolid:
799 num = match_strdup(&args[0]);
800 if (num) {
801 *subvol_objectid = memparse(num, NULL);
802 kfree(num);
803 /* we want the original fs_tree */
804 if (!*subvol_objectid)
805 *subvol_objectid =
806 BTRFS_FS_TREE_OBJECTID;
807 } else {
808 error = -EINVAL;
809 goto out;
810 }
811 break;
812 case Opt_subvolrootid:
813 printk(KERN_WARNING
814 "BTRFS: 'subvolrootid' mount option is deprecated and has "
815 "no effect\n");
816 break;
817 case Opt_device:
818 device_name = match_strdup(&args[0]);
819 if (!device_name) {
820 error = -ENOMEM;
821 goto out;
822 }
823 error = btrfs_scan_one_device(device_name,
824 flags, holder, fs_devices);
825 kfree(device_name);
826 if (error)
827 goto out;
828 break;
829 default:
830 break;
831 }
832 }
833
834 out:
835 kfree(orig);
836 return error;
837 }
838
839 static struct dentry *get_default_root(struct super_block *sb,
840 u64 subvol_objectid)
841 {
842 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
843 struct btrfs_root *root = fs_info->tree_root;
844 struct btrfs_root *new_root;
845 struct btrfs_dir_item *di;
846 struct btrfs_path *path;
847 struct btrfs_key location;
848 struct inode *inode;
849 u64 dir_id;
850 int new = 0;
851
852 /*
853 * We have a specific subvol we want to mount, just setup location and
854 * go look up the root.
855 */
856 if (subvol_objectid) {
857 location.objectid = subvol_objectid;
858 location.type = BTRFS_ROOT_ITEM_KEY;
859 location.offset = (u64)-1;
860 goto find_root;
861 }
862
863 path = btrfs_alloc_path();
864 if (!path)
865 return ERR_PTR(-ENOMEM);
866 path->leave_spinning = 1;
867
868 /*
869 * Find the "default" dir item which points to the root item that we
870 * will mount by default if we haven't been given a specific subvolume
871 * to mount.
872 */
873 dir_id = btrfs_super_root_dir(fs_info->super_copy);
874 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
875 if (IS_ERR(di)) {
876 btrfs_free_path(path);
877 return ERR_CAST(di);
878 }
879 if (!di) {
880 /*
881 * Ok the default dir item isn't there. This is weird since
882 * it's always been there, but don't freak out, just try and
883 * mount to root most subvolume.
884 */
885 btrfs_free_path(path);
886 dir_id = BTRFS_FIRST_FREE_OBJECTID;
887 new_root = fs_info->fs_root;
888 goto setup_root;
889 }
890
891 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
892 btrfs_free_path(path);
893
894 find_root:
895 new_root = btrfs_read_fs_root_no_name(fs_info, &location);
896 if (IS_ERR(new_root))
897 return ERR_CAST(new_root);
898
899 if (!(sb->s_flags & MS_RDONLY)) {
900 int ret;
901 down_read(&fs_info->cleanup_work_sem);
902 ret = btrfs_orphan_cleanup(new_root);
903 up_read(&fs_info->cleanup_work_sem);
904 if (ret)
905 return ERR_PTR(ret);
906 }
907
908 dir_id = btrfs_root_dirid(&new_root->root_item);
909 setup_root:
910 location.objectid = dir_id;
911 location.type = BTRFS_INODE_ITEM_KEY;
912 location.offset = 0;
913
914 inode = btrfs_iget(sb, &location, new_root, &new);
915 if (IS_ERR(inode))
916 return ERR_CAST(inode);
917
918 /*
919 * If we're just mounting the root most subvol put the inode and return
920 * a reference to the dentry. We will have already gotten a reference
921 * to the inode in btrfs_fill_super so we're good to go.
922 */
923 if (!new && d_inode(sb->s_root) == inode) {
924 iput(inode);
925 return dget(sb->s_root);
926 }
927
928 return d_obtain_root(inode);
929 }
930
931 static int btrfs_fill_super(struct super_block *sb,
932 struct btrfs_fs_devices *fs_devices,
933 void *data, int silent)
934 {
935 struct inode *inode;
936 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
937 struct btrfs_key key;
938 int err;
939
940 sb->s_maxbytes = MAX_LFS_FILESIZE;
941 sb->s_magic = BTRFS_SUPER_MAGIC;
942 sb->s_op = &btrfs_super_ops;
943 sb->s_d_op = &btrfs_dentry_operations;
944 sb->s_export_op = &btrfs_export_ops;
945 sb->s_xattr = btrfs_xattr_handlers;
946 sb->s_time_gran = 1;
947 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
948 sb->s_flags |= MS_POSIXACL;
949 #endif
950 sb->s_flags |= MS_I_VERSION;
951 err = open_ctree(sb, fs_devices, (char *)data);
952 if (err) {
953 printk(KERN_ERR "BTRFS: open_ctree failed\n");
954 return err;
955 }
956
957 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
958 key.type = BTRFS_INODE_ITEM_KEY;
959 key.offset = 0;
960 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
961 if (IS_ERR(inode)) {
962 err = PTR_ERR(inode);
963 goto fail_close;
964 }
965
966 sb->s_root = d_make_root(inode);
967 if (!sb->s_root) {
968 err = -ENOMEM;
969 goto fail_close;
970 }
971
972 save_mount_options(sb, data);
973 cleancache_init_fs(sb);
974 sb->s_flags |= MS_ACTIVE;
975 return 0;
976
977 fail_close:
978 close_ctree(fs_info->tree_root);
979 return err;
980 }
981
982 int btrfs_sync_fs(struct super_block *sb, int wait)
983 {
984 struct btrfs_trans_handle *trans;
985 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
986 struct btrfs_root *root = fs_info->tree_root;
987
988 trace_btrfs_sync_fs(wait);
989
990 if (!wait) {
991 filemap_flush(fs_info->btree_inode->i_mapping);
992 return 0;
993 }
994
995 btrfs_wait_ordered_roots(fs_info, -1);
996
997 trans = btrfs_attach_transaction_barrier(root);
998 if (IS_ERR(trans)) {
999 /* no transaction, don't bother */
1000 if (PTR_ERR(trans) == -ENOENT) {
1001 /*
1002 * Exit unless we have some pending changes
1003 * that need to go through commit
1004 */
1005 if (fs_info->pending_changes == 0)
1006 return 0;
1007 /*
1008 * A non-blocking test if the fs is frozen. We must not
1009 * start a new transaction here otherwise a deadlock
1010 * happens. The pending operations are delayed to the
1011 * next commit after thawing.
1012 */
1013 if (__sb_start_write(sb, SB_FREEZE_WRITE, false))
1014 __sb_end_write(sb, SB_FREEZE_WRITE);
1015 else
1016 return 0;
1017 trans = btrfs_start_transaction(root, 0);
1018 }
1019 if (IS_ERR(trans))
1020 return PTR_ERR(trans);
1021 }
1022 return btrfs_commit_transaction(trans, root);
1023 }
1024
1025 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
1026 {
1027 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
1028 struct btrfs_root *root = info->tree_root;
1029 char *compress_type;
1030
1031 if (btrfs_test_opt(root, DEGRADED))
1032 seq_puts(seq, ",degraded");
1033 if (btrfs_test_opt(root, NODATASUM))
1034 seq_puts(seq, ",nodatasum");
1035 if (btrfs_test_opt(root, NODATACOW))
1036 seq_puts(seq, ",nodatacow");
1037 if (btrfs_test_opt(root, NOBARRIER))
1038 seq_puts(seq, ",nobarrier");
1039 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE)
1040 seq_printf(seq, ",max_inline=%llu", info->max_inline);
1041 if (info->alloc_start != 0)
1042 seq_printf(seq, ",alloc_start=%llu", info->alloc_start);
1043 if (info->thread_pool_size != min_t(unsigned long,
1044 num_online_cpus() + 2, 8))
1045 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
1046 if (btrfs_test_opt(root, COMPRESS)) {
1047 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
1048 compress_type = "zlib";
1049 else
1050 compress_type = "lzo";
1051 if (btrfs_test_opt(root, FORCE_COMPRESS))
1052 seq_printf(seq, ",compress-force=%s", compress_type);
1053 else
1054 seq_printf(seq, ",compress=%s", compress_type);
1055 }
1056 if (btrfs_test_opt(root, NOSSD))
1057 seq_puts(seq, ",nossd");
1058 if (btrfs_test_opt(root, SSD_SPREAD))
1059 seq_puts(seq, ",ssd_spread");
1060 else if (btrfs_test_opt(root, SSD))
1061 seq_puts(seq, ",ssd");
1062 if (btrfs_test_opt(root, NOTREELOG))
1063 seq_puts(seq, ",notreelog");
1064 if (btrfs_test_opt(root, FLUSHONCOMMIT))
1065 seq_puts(seq, ",flushoncommit");
1066 if (btrfs_test_opt(root, DISCARD))
1067 seq_puts(seq, ",discard");
1068 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
1069 seq_puts(seq, ",noacl");
1070 if (btrfs_test_opt(root, SPACE_CACHE))
1071 seq_puts(seq, ",space_cache");
1072 else
1073 seq_puts(seq, ",nospace_cache");
1074 if (btrfs_test_opt(root, RESCAN_UUID_TREE))
1075 seq_puts(seq, ",rescan_uuid_tree");
1076 if (btrfs_test_opt(root, CLEAR_CACHE))
1077 seq_puts(seq, ",clear_cache");
1078 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1079 seq_puts(seq, ",user_subvol_rm_allowed");
1080 if (btrfs_test_opt(root, ENOSPC_DEBUG))
1081 seq_puts(seq, ",enospc_debug");
1082 if (btrfs_test_opt(root, AUTO_DEFRAG))
1083 seq_puts(seq, ",autodefrag");
1084 if (btrfs_test_opt(root, INODE_MAP_CACHE))
1085 seq_puts(seq, ",inode_cache");
1086 if (btrfs_test_opt(root, SKIP_BALANCE))
1087 seq_puts(seq, ",skip_balance");
1088 if (btrfs_test_opt(root, RECOVERY))
1089 seq_puts(seq, ",recovery");
1090 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1091 if (btrfs_test_opt(root, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1092 seq_puts(seq, ",check_int_data");
1093 else if (btrfs_test_opt(root, CHECK_INTEGRITY))
1094 seq_puts(seq, ",check_int");
1095 if (info->check_integrity_print_mask)
1096 seq_printf(seq, ",check_int_print_mask=%d",
1097 info->check_integrity_print_mask);
1098 #endif
1099 if (info->metadata_ratio)
1100 seq_printf(seq, ",metadata_ratio=%d",
1101 info->metadata_ratio);
1102 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
1103 seq_puts(seq, ",fatal_errors=panic");
1104 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1105 seq_printf(seq, ",commit=%d", info->commit_interval);
1106 return 0;
1107 }
1108
1109 static int btrfs_test_super(struct super_block *s, void *data)
1110 {
1111 struct btrfs_fs_info *p = data;
1112 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1113
1114 return fs_info->fs_devices == p->fs_devices;
1115 }
1116
1117 static int btrfs_set_super(struct super_block *s, void *data)
1118 {
1119 int err = set_anon_super(s, data);
1120 if (!err)
1121 s->s_fs_info = data;
1122 return err;
1123 }
1124
1125 /*
1126 * subvolumes are identified by ino 256
1127 */
1128 static inline int is_subvolume_inode(struct inode *inode)
1129 {
1130 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1131 return 1;
1132 return 0;
1133 }
1134
1135 /*
1136 * This will add subvolid=0 to the argument string while removing any subvol=
1137 * and subvolid= arguments to make sure we get the top-level root for path
1138 * walking to the subvol we want.
1139 */
1140 static char *setup_root_args(char *args)
1141 {
1142 char *buf, *dst, *sep;
1143
1144 if (!args)
1145 return kstrdup("subvolid=0", GFP_NOFS);
1146
1147 /* The worst case is that we add ",subvolid=0" to the end. */
1148 buf = dst = kmalloc(strlen(args) + strlen(",subvolid=0") + 1, GFP_NOFS);
1149 if (!buf)
1150 return NULL;
1151
1152 while (1) {
1153 sep = strchrnul(args, ',');
1154 if (!strstarts(args, "subvol=") &&
1155 !strstarts(args, "subvolid=")) {
1156 memcpy(dst, args, sep - args);
1157 dst += sep - args;
1158 *dst++ = ',';
1159 }
1160 if (*sep)
1161 args = sep + 1;
1162 else
1163 break;
1164 }
1165 strcpy(dst, "subvolid=0");
1166
1167 return buf;
1168 }
1169
1170 static struct dentry *mount_subvol(const char *subvol_name, int flags,
1171 const char *device_name, char *data)
1172 {
1173 struct dentry *root;
1174 struct vfsmount *mnt = NULL;
1175 char *newargs;
1176 int ret;
1177
1178 newargs = setup_root_args(data);
1179 if (!newargs) {
1180 root = ERR_PTR(-ENOMEM);
1181 goto out;
1182 }
1183
1184 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, newargs);
1185 if (PTR_ERR_OR_ZERO(mnt) == -EBUSY) {
1186 if (flags & MS_RDONLY) {
1187 mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~MS_RDONLY,
1188 device_name, newargs);
1189 } else {
1190 mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY,
1191 device_name, newargs);
1192 if (IS_ERR(mnt)) {
1193 root = ERR_CAST(mnt);
1194 mnt = NULL;
1195 goto out;
1196 }
1197
1198 down_write(&mnt->mnt_sb->s_umount);
1199 ret = btrfs_remount(mnt->mnt_sb, &flags, NULL);
1200 up_write(&mnt->mnt_sb->s_umount);
1201 if (ret < 0) {
1202 root = ERR_PTR(ret);
1203 goto out;
1204 }
1205 }
1206 }
1207 if (IS_ERR(mnt)) {
1208 root = ERR_CAST(mnt);
1209 mnt = NULL;
1210 goto out;
1211 }
1212
1213 root = mount_subtree(mnt, subvol_name);
1214 /* mount_subtree() drops our reference on the vfsmount. */
1215 mnt = NULL;
1216
1217 if (!IS_ERR(root) && !is_subvolume_inode(d_inode(root))) {
1218 struct super_block *s = root->d_sb;
1219 dput(root);
1220 root = ERR_PTR(-EINVAL);
1221 deactivate_locked_super(s);
1222 pr_err("BTRFS: '%s' is not a valid subvolume\n", subvol_name);
1223 }
1224
1225 out:
1226 mntput(mnt);
1227 kfree(newargs);
1228 kfree(subvol_name);
1229 return root;
1230 }
1231
1232 static int parse_security_options(char *orig_opts,
1233 struct security_mnt_opts *sec_opts)
1234 {
1235 char *secdata = NULL;
1236 int ret = 0;
1237
1238 secdata = alloc_secdata();
1239 if (!secdata)
1240 return -ENOMEM;
1241 ret = security_sb_copy_data(orig_opts, secdata);
1242 if (ret) {
1243 free_secdata(secdata);
1244 return ret;
1245 }
1246 ret = security_sb_parse_opts_str(secdata, sec_opts);
1247 free_secdata(secdata);
1248 return ret;
1249 }
1250
1251 static int setup_security_options(struct btrfs_fs_info *fs_info,
1252 struct super_block *sb,
1253 struct security_mnt_opts *sec_opts)
1254 {
1255 int ret = 0;
1256
1257 /*
1258 * Call security_sb_set_mnt_opts() to check whether new sec_opts
1259 * is valid.
1260 */
1261 ret = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL);
1262 if (ret)
1263 return ret;
1264
1265 #ifdef CONFIG_SECURITY
1266 if (!fs_info->security_opts.num_mnt_opts) {
1267 /* first time security setup, copy sec_opts to fs_info */
1268 memcpy(&fs_info->security_opts, sec_opts, sizeof(*sec_opts));
1269 } else {
1270 /*
1271 * Since SELinux(the only one supports security_mnt_opts) does
1272 * NOT support changing context during remount/mount same sb,
1273 * This must be the same or part of the same security options,
1274 * just free it.
1275 */
1276 security_free_mnt_opts(sec_opts);
1277 }
1278 #endif
1279 return ret;
1280 }
1281
1282 /*
1283 * Find a superblock for the given device / mount point.
1284 *
1285 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1286 * for multiple device setup. Make sure to keep it in sync.
1287 */
1288 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1289 const char *device_name, void *data)
1290 {
1291 struct block_device *bdev = NULL;
1292 struct super_block *s;
1293 struct dentry *root;
1294 struct btrfs_fs_devices *fs_devices = NULL;
1295 struct btrfs_fs_info *fs_info = NULL;
1296 struct security_mnt_opts new_sec_opts;
1297 fmode_t mode = FMODE_READ;
1298 char *subvol_name = NULL;
1299 u64 subvol_objectid = 0;
1300 int error = 0;
1301
1302 if (!(flags & MS_RDONLY))
1303 mode |= FMODE_WRITE;
1304
1305 error = btrfs_parse_early_options(data, mode, fs_type,
1306 &subvol_name, &subvol_objectid,
1307 &fs_devices);
1308 if (error) {
1309 kfree(subvol_name);
1310 return ERR_PTR(error);
1311 }
1312
1313 if (subvol_name) {
1314 /* mount_subvol() will free subvol_name. */
1315 return mount_subvol(subvol_name, flags, device_name, data);
1316 }
1317
1318 security_init_mnt_opts(&new_sec_opts);
1319 if (data) {
1320 error = parse_security_options(data, &new_sec_opts);
1321 if (error)
1322 return ERR_PTR(error);
1323 }
1324
1325 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1326 if (error)
1327 goto error_sec_opts;
1328
1329 /*
1330 * Setup a dummy root and fs_info for test/set super. This is because
1331 * we don't actually fill this stuff out until open_ctree, but we need
1332 * it for searching for existing supers, so this lets us do that and
1333 * then open_ctree will properly initialize everything later.
1334 */
1335 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1336 if (!fs_info) {
1337 error = -ENOMEM;
1338 goto error_sec_opts;
1339 }
1340
1341 fs_info->fs_devices = fs_devices;
1342
1343 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1344 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1345 security_init_mnt_opts(&fs_info->security_opts);
1346 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1347 error = -ENOMEM;
1348 goto error_fs_info;
1349 }
1350
1351 error = btrfs_open_devices(fs_devices, mode, fs_type);
1352 if (error)
1353 goto error_fs_info;
1354
1355 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1356 error = -EACCES;
1357 goto error_close_devices;
1358 }
1359
1360 bdev = fs_devices->latest_bdev;
1361 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1362 fs_info);
1363 if (IS_ERR(s)) {
1364 error = PTR_ERR(s);
1365 goto error_close_devices;
1366 }
1367
1368 if (s->s_root) {
1369 btrfs_close_devices(fs_devices);
1370 free_fs_info(fs_info);
1371 if ((flags ^ s->s_flags) & MS_RDONLY)
1372 error = -EBUSY;
1373 } else {
1374 char b[BDEVNAME_SIZE];
1375
1376 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1377 btrfs_sb(s)->bdev_holder = fs_type;
1378 error = btrfs_fill_super(s, fs_devices, data,
1379 flags & MS_SILENT ? 1 : 0);
1380 }
1381
1382 root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1383 if (IS_ERR(root)) {
1384 deactivate_locked_super(s);
1385 error = PTR_ERR(root);
1386 goto error_sec_opts;
1387 }
1388
1389 fs_info = btrfs_sb(s);
1390 error = setup_security_options(fs_info, s, &new_sec_opts);
1391 if (error) {
1392 dput(root);
1393 deactivate_locked_super(s);
1394 goto error_sec_opts;
1395 }
1396
1397 return root;
1398
1399 error_close_devices:
1400 btrfs_close_devices(fs_devices);
1401 error_fs_info:
1402 free_fs_info(fs_info);
1403 error_sec_opts:
1404 security_free_mnt_opts(&new_sec_opts);
1405 return ERR_PTR(error);
1406 }
1407
1408 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1409 int new_pool_size, int old_pool_size)
1410 {
1411 if (new_pool_size == old_pool_size)
1412 return;
1413
1414 fs_info->thread_pool_size = new_pool_size;
1415
1416 btrfs_info(fs_info, "resize thread pool %d -> %d",
1417 old_pool_size, new_pool_size);
1418
1419 btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
1420 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
1421 btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size);
1422 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
1423 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
1424 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
1425 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
1426 new_pool_size);
1427 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
1428 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
1429 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
1430 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size);
1431 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers,
1432 new_pool_size);
1433 }
1434
1435 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1436 {
1437 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1438 }
1439
1440 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1441 unsigned long old_opts, int flags)
1442 {
1443 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1444 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1445 (flags & MS_RDONLY))) {
1446 /* wait for any defraggers to finish */
1447 wait_event(fs_info->transaction_wait,
1448 (atomic_read(&fs_info->defrag_running) == 0));
1449 if (flags & MS_RDONLY)
1450 sync_filesystem(fs_info->sb);
1451 }
1452 }
1453
1454 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1455 unsigned long old_opts)
1456 {
1457 /*
1458 * We need cleanup all defragable inodes if the autodefragment is
1459 * close or the fs is R/O.
1460 */
1461 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1462 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1463 (fs_info->sb->s_flags & MS_RDONLY))) {
1464 btrfs_cleanup_defrag_inodes(fs_info);
1465 }
1466
1467 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1468 }
1469
1470 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1471 {
1472 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1473 struct btrfs_root *root = fs_info->tree_root;
1474 unsigned old_flags = sb->s_flags;
1475 unsigned long old_opts = fs_info->mount_opt;
1476 unsigned long old_compress_type = fs_info->compress_type;
1477 u64 old_max_inline = fs_info->max_inline;
1478 u64 old_alloc_start = fs_info->alloc_start;
1479 int old_thread_pool_size = fs_info->thread_pool_size;
1480 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1481 int ret;
1482
1483 sync_filesystem(sb);
1484 btrfs_remount_prepare(fs_info);
1485
1486 if (data) {
1487 struct security_mnt_opts new_sec_opts;
1488
1489 security_init_mnt_opts(&new_sec_opts);
1490 ret = parse_security_options(data, &new_sec_opts);
1491 if (ret)
1492 goto restore;
1493 ret = setup_security_options(fs_info, sb,
1494 &new_sec_opts);
1495 if (ret) {
1496 security_free_mnt_opts(&new_sec_opts);
1497 goto restore;
1498 }
1499 }
1500
1501 ret = btrfs_parse_options(root, data);
1502 if (ret) {
1503 ret = -EINVAL;
1504 goto restore;
1505 }
1506
1507 btrfs_remount_begin(fs_info, old_opts, *flags);
1508 btrfs_resize_thread_pool(fs_info,
1509 fs_info->thread_pool_size, old_thread_pool_size);
1510
1511 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1512 goto out;
1513
1514 if (*flags & MS_RDONLY) {
1515 /*
1516 * this also happens on 'umount -rf' or on shutdown, when
1517 * the filesystem is busy.
1518 */
1519 cancel_work_sync(&fs_info->async_reclaim_work);
1520
1521 /* wait for the uuid_scan task to finish */
1522 down(&fs_info->uuid_tree_rescan_sem);
1523 /* avoid complains from lockdep et al. */
1524 up(&fs_info->uuid_tree_rescan_sem);
1525
1526 sb->s_flags |= MS_RDONLY;
1527
1528 btrfs_dev_replace_suspend_for_unmount(fs_info);
1529 btrfs_scrub_cancel(fs_info);
1530 btrfs_pause_balance(fs_info);
1531
1532 ret = btrfs_commit_super(root);
1533 if (ret)
1534 goto restore;
1535 } else {
1536 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
1537 btrfs_err(fs_info,
1538 "Remounting read-write after error is not allowed");
1539 ret = -EINVAL;
1540 goto restore;
1541 }
1542 if (fs_info->fs_devices->rw_devices == 0) {
1543 ret = -EACCES;
1544 goto restore;
1545 }
1546
1547 if (fs_info->fs_devices->missing_devices >
1548 fs_info->num_tolerated_disk_barrier_failures &&
1549 !(*flags & MS_RDONLY)) {
1550 btrfs_warn(fs_info,
1551 "too many missing devices, writeable remount is not allowed");
1552 ret = -EACCES;
1553 goto restore;
1554 }
1555
1556 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1557 ret = -EINVAL;
1558 goto restore;
1559 }
1560
1561 ret = btrfs_cleanup_fs_roots(fs_info);
1562 if (ret)
1563 goto restore;
1564
1565 /* recover relocation */
1566 mutex_lock(&fs_info->cleaner_mutex);
1567 ret = btrfs_recover_relocation(root);
1568 mutex_unlock(&fs_info->cleaner_mutex);
1569 if (ret)
1570 goto restore;
1571
1572 ret = btrfs_resume_balance_async(fs_info);
1573 if (ret)
1574 goto restore;
1575
1576 ret = btrfs_resume_dev_replace_async(fs_info);
1577 if (ret) {
1578 btrfs_warn(fs_info, "failed to resume dev_replace");
1579 goto restore;
1580 }
1581
1582 if (!fs_info->uuid_root) {
1583 btrfs_info(fs_info, "creating UUID tree");
1584 ret = btrfs_create_uuid_tree(fs_info);
1585 if (ret) {
1586 btrfs_warn(fs_info, "failed to create the UUID tree %d", ret);
1587 goto restore;
1588 }
1589 }
1590 sb->s_flags &= ~MS_RDONLY;
1591 }
1592 out:
1593 wake_up_process(fs_info->transaction_kthread);
1594 btrfs_remount_cleanup(fs_info, old_opts);
1595 return 0;
1596
1597 restore:
1598 /* We've hit an error - don't reset MS_RDONLY */
1599 if (sb->s_flags & MS_RDONLY)
1600 old_flags |= MS_RDONLY;
1601 sb->s_flags = old_flags;
1602 fs_info->mount_opt = old_opts;
1603 fs_info->compress_type = old_compress_type;
1604 fs_info->max_inline = old_max_inline;
1605 mutex_lock(&fs_info->chunk_mutex);
1606 fs_info->alloc_start = old_alloc_start;
1607 mutex_unlock(&fs_info->chunk_mutex);
1608 btrfs_resize_thread_pool(fs_info,
1609 old_thread_pool_size, fs_info->thread_pool_size);
1610 fs_info->metadata_ratio = old_metadata_ratio;
1611 btrfs_remount_cleanup(fs_info, old_opts);
1612 return ret;
1613 }
1614
1615 /* Used to sort the devices by max_avail(descending sort) */
1616 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1617 const void *dev_info2)
1618 {
1619 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1620 ((struct btrfs_device_info *)dev_info2)->max_avail)
1621 return -1;
1622 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1623 ((struct btrfs_device_info *)dev_info2)->max_avail)
1624 return 1;
1625 else
1626 return 0;
1627 }
1628
1629 /*
1630 * sort the devices by max_avail, in which max free extent size of each device
1631 * is stored.(Descending Sort)
1632 */
1633 static inline void btrfs_descending_sort_devices(
1634 struct btrfs_device_info *devices,
1635 size_t nr_devices)
1636 {
1637 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1638 btrfs_cmp_device_free_bytes, NULL);
1639 }
1640
1641 /*
1642 * The helper to calc the free space on the devices that can be used to store
1643 * file data.
1644 */
1645 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1646 {
1647 struct btrfs_fs_info *fs_info = root->fs_info;
1648 struct btrfs_device_info *devices_info;
1649 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1650 struct btrfs_device *device;
1651 u64 skip_space;
1652 u64 type;
1653 u64 avail_space;
1654 u64 used_space;
1655 u64 min_stripe_size;
1656 int min_stripes = 1, num_stripes = 1;
1657 int i = 0, nr_devices;
1658 int ret;
1659
1660 /*
1661 * We aren't under the device list lock, so this is racey-ish, but good
1662 * enough for our purposes.
1663 */
1664 nr_devices = fs_info->fs_devices->open_devices;
1665 if (!nr_devices) {
1666 smp_mb();
1667 nr_devices = fs_info->fs_devices->open_devices;
1668 ASSERT(nr_devices);
1669 if (!nr_devices) {
1670 *free_bytes = 0;
1671 return 0;
1672 }
1673 }
1674
1675 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1676 GFP_NOFS);
1677 if (!devices_info)
1678 return -ENOMEM;
1679
1680 /* calc min stripe number for data space alloction */
1681 type = btrfs_get_alloc_profile(root, 1);
1682 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1683 min_stripes = 2;
1684 num_stripes = nr_devices;
1685 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1686 min_stripes = 2;
1687 num_stripes = 2;
1688 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1689 min_stripes = 4;
1690 num_stripes = 4;
1691 }
1692
1693 if (type & BTRFS_BLOCK_GROUP_DUP)
1694 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1695 else
1696 min_stripe_size = BTRFS_STRIPE_LEN;
1697
1698 if (fs_info->alloc_start)
1699 mutex_lock(&fs_devices->device_list_mutex);
1700 rcu_read_lock();
1701 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
1702 if (!device->in_fs_metadata || !device->bdev ||
1703 device->is_tgtdev_for_dev_replace)
1704 continue;
1705
1706 if (i >= nr_devices)
1707 break;
1708
1709 avail_space = device->total_bytes - device->bytes_used;
1710
1711 /* align with stripe_len */
1712 avail_space = div_u64(avail_space, BTRFS_STRIPE_LEN);
1713 avail_space *= BTRFS_STRIPE_LEN;
1714
1715 /*
1716 * In order to avoid overwritting the superblock on the drive,
1717 * btrfs starts at an offset of at least 1MB when doing chunk
1718 * allocation.
1719 */
1720 skip_space = 1024 * 1024;
1721
1722 /* user can set the offset in fs_info->alloc_start. */
1723 if (fs_info->alloc_start &&
1724 fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1725 device->total_bytes) {
1726 rcu_read_unlock();
1727 skip_space = max(fs_info->alloc_start, skip_space);
1728
1729 /*
1730 * btrfs can not use the free space in
1731 * [0, skip_space - 1], we must subtract it from the
1732 * total. In order to implement it, we account the used
1733 * space in this range first.
1734 */
1735 ret = btrfs_account_dev_extents_size(device, 0,
1736 skip_space - 1,
1737 &used_space);
1738 if (ret) {
1739 kfree(devices_info);
1740 mutex_unlock(&fs_devices->device_list_mutex);
1741 return ret;
1742 }
1743
1744 rcu_read_lock();
1745
1746 /* calc the free space in [0, skip_space - 1] */
1747 skip_space -= used_space;
1748 }
1749
1750 /*
1751 * we can use the free space in [0, skip_space - 1], subtract
1752 * it from the total.
1753 */
1754 if (avail_space && avail_space >= skip_space)
1755 avail_space -= skip_space;
1756 else
1757 avail_space = 0;
1758
1759 if (avail_space < min_stripe_size)
1760 continue;
1761
1762 devices_info[i].dev = device;
1763 devices_info[i].max_avail = avail_space;
1764
1765 i++;
1766 }
1767 rcu_read_unlock();
1768 if (fs_info->alloc_start)
1769 mutex_unlock(&fs_devices->device_list_mutex);
1770
1771 nr_devices = i;
1772
1773 btrfs_descending_sort_devices(devices_info, nr_devices);
1774
1775 i = nr_devices - 1;
1776 avail_space = 0;
1777 while (nr_devices >= min_stripes) {
1778 if (num_stripes > nr_devices)
1779 num_stripes = nr_devices;
1780
1781 if (devices_info[i].max_avail >= min_stripe_size) {
1782 int j;
1783 u64 alloc_size;
1784
1785 avail_space += devices_info[i].max_avail * num_stripes;
1786 alloc_size = devices_info[i].max_avail;
1787 for (j = i + 1 - num_stripes; j <= i; j++)
1788 devices_info[j].max_avail -= alloc_size;
1789 }
1790 i--;
1791 nr_devices--;
1792 }
1793
1794 kfree(devices_info);
1795 *free_bytes = avail_space;
1796 return 0;
1797 }
1798
1799 /*
1800 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles.
1801 *
1802 * If there's a redundant raid level at DATA block groups, use the respective
1803 * multiplier to scale the sizes.
1804 *
1805 * Unused device space usage is based on simulating the chunk allocator
1806 * algorithm that respects the device sizes, order of allocations and the
1807 * 'alloc_start' value, this is a close approximation of the actual use but
1808 * there are other factors that may change the result (like a new metadata
1809 * chunk).
1810 *
1811 * FIXME: not accurate for mixed block groups, total and free/used are ok,
1812 * available appears slightly larger.
1813 */
1814 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1815 {
1816 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1817 struct btrfs_super_block *disk_super = fs_info->super_copy;
1818 struct list_head *head = &fs_info->space_info;
1819 struct btrfs_space_info *found;
1820 u64 total_used = 0;
1821 u64 total_free_data = 0;
1822 int bits = dentry->d_sb->s_blocksize_bits;
1823 __be32 *fsid = (__be32 *)fs_info->fsid;
1824 unsigned factor = 1;
1825 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
1826 int ret;
1827
1828 /*
1829 * holding chunk_muext to avoid allocating new chunks, holding
1830 * device_list_mutex to avoid the device being removed
1831 */
1832 rcu_read_lock();
1833 list_for_each_entry_rcu(found, head, list) {
1834 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1835 int i;
1836
1837 total_free_data += found->disk_total - found->disk_used;
1838 total_free_data -=
1839 btrfs_account_ro_block_groups_free_space(found);
1840
1841 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1842 if (!list_empty(&found->block_groups[i])) {
1843 switch (i) {
1844 case BTRFS_RAID_DUP:
1845 case BTRFS_RAID_RAID1:
1846 case BTRFS_RAID_RAID10:
1847 factor = 2;
1848 }
1849 }
1850 }
1851 }
1852
1853 total_used += found->disk_used;
1854 }
1855
1856 rcu_read_unlock();
1857
1858 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor);
1859 buf->f_blocks >>= bits;
1860 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits);
1861
1862 /* Account global block reserve as used, it's in logical size already */
1863 spin_lock(&block_rsv->lock);
1864 buf->f_bfree -= block_rsv->size >> bits;
1865 spin_unlock(&block_rsv->lock);
1866
1867 buf->f_bavail = div_u64(total_free_data, factor);
1868 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1869 if (ret)
1870 return ret;
1871 buf->f_bavail += div_u64(total_free_data, factor);
1872 buf->f_bavail = buf->f_bavail >> bits;
1873
1874 buf->f_type = BTRFS_SUPER_MAGIC;
1875 buf->f_bsize = dentry->d_sb->s_blocksize;
1876 buf->f_namelen = BTRFS_NAME_LEN;
1877
1878 /* We treat it as constant endianness (it doesn't matter _which_)
1879 because we want the fsid to come out the same whether mounted
1880 on a big-endian or little-endian host */
1881 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1882 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1883 /* Mask in the root object ID too, to disambiguate subvols */
1884 buf->f_fsid.val[0] ^= BTRFS_I(d_inode(dentry))->root->objectid >> 32;
1885 buf->f_fsid.val[1] ^= BTRFS_I(d_inode(dentry))->root->objectid;
1886
1887 return 0;
1888 }
1889
1890 static void btrfs_kill_super(struct super_block *sb)
1891 {
1892 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1893 kill_anon_super(sb);
1894 free_fs_info(fs_info);
1895 }
1896
1897 static struct file_system_type btrfs_fs_type = {
1898 .owner = THIS_MODULE,
1899 .name = "btrfs",
1900 .mount = btrfs_mount,
1901 .kill_sb = btrfs_kill_super,
1902 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
1903 };
1904 MODULE_ALIAS_FS("btrfs");
1905
1906 static int btrfs_control_open(struct inode *inode, struct file *file)
1907 {
1908 /*
1909 * The control file's private_data is used to hold the
1910 * transaction when it is started and is used to keep
1911 * track of whether a transaction is already in progress.
1912 */
1913 file->private_data = NULL;
1914 return 0;
1915 }
1916
1917 /*
1918 * used by btrfsctl to scan devices when no FS is mounted
1919 */
1920 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1921 unsigned long arg)
1922 {
1923 struct btrfs_ioctl_vol_args *vol;
1924 struct btrfs_fs_devices *fs_devices;
1925 int ret = -ENOTTY;
1926
1927 if (!capable(CAP_SYS_ADMIN))
1928 return -EPERM;
1929
1930 vol = memdup_user((void __user *)arg, sizeof(*vol));
1931 if (IS_ERR(vol))
1932 return PTR_ERR(vol);
1933
1934 switch (cmd) {
1935 case BTRFS_IOC_SCAN_DEV:
1936 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1937 &btrfs_fs_type, &fs_devices);
1938 break;
1939 case BTRFS_IOC_DEVICES_READY:
1940 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1941 &btrfs_fs_type, &fs_devices);
1942 if (ret)
1943 break;
1944 ret = !(fs_devices->num_devices == fs_devices->total_devices);
1945 break;
1946 }
1947
1948 kfree(vol);
1949 return ret;
1950 }
1951
1952 static int btrfs_freeze(struct super_block *sb)
1953 {
1954 struct btrfs_trans_handle *trans;
1955 struct btrfs_root *root = btrfs_sb(sb)->tree_root;
1956
1957 trans = btrfs_attach_transaction_barrier(root);
1958 if (IS_ERR(trans)) {
1959 /* no transaction, don't bother */
1960 if (PTR_ERR(trans) == -ENOENT)
1961 return 0;
1962 return PTR_ERR(trans);
1963 }
1964 return btrfs_commit_transaction(trans, root);
1965 }
1966
1967 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1968 {
1969 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1970 struct btrfs_fs_devices *cur_devices;
1971 struct btrfs_device *dev, *first_dev = NULL;
1972 struct list_head *head;
1973 struct rcu_string *name;
1974
1975 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1976 cur_devices = fs_info->fs_devices;
1977 while (cur_devices) {
1978 head = &cur_devices->devices;
1979 list_for_each_entry(dev, head, dev_list) {
1980 if (dev->missing)
1981 continue;
1982 if (!dev->name)
1983 continue;
1984 if (!first_dev || dev->devid < first_dev->devid)
1985 first_dev = dev;
1986 }
1987 cur_devices = cur_devices->seed;
1988 }
1989
1990 if (first_dev) {
1991 rcu_read_lock();
1992 name = rcu_dereference(first_dev->name);
1993 seq_escape(m, name->str, " \t\n\\");
1994 rcu_read_unlock();
1995 } else {
1996 WARN_ON(1);
1997 }
1998 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1999 return 0;
2000 }
2001
2002 static const struct super_operations btrfs_super_ops = {
2003 .drop_inode = btrfs_drop_inode,
2004 .evict_inode = btrfs_evict_inode,
2005 .put_super = btrfs_put_super,
2006 .sync_fs = btrfs_sync_fs,
2007 .show_options = btrfs_show_options,
2008 .show_devname = btrfs_show_devname,
2009 .write_inode = btrfs_write_inode,
2010 .alloc_inode = btrfs_alloc_inode,
2011 .destroy_inode = btrfs_destroy_inode,
2012 .statfs = btrfs_statfs,
2013 .remount_fs = btrfs_remount,
2014 .freeze_fs = btrfs_freeze,
2015 };
2016
2017 static const struct file_operations btrfs_ctl_fops = {
2018 .open = btrfs_control_open,
2019 .unlocked_ioctl = btrfs_control_ioctl,
2020 .compat_ioctl = btrfs_control_ioctl,
2021 .owner = THIS_MODULE,
2022 .llseek = noop_llseek,
2023 };
2024
2025 static struct miscdevice btrfs_misc = {
2026 .minor = BTRFS_MINOR,
2027 .name = "btrfs-control",
2028 .fops = &btrfs_ctl_fops
2029 };
2030
2031 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
2032 MODULE_ALIAS("devname:btrfs-control");
2033
2034 static int btrfs_interface_init(void)
2035 {
2036 return misc_register(&btrfs_misc);
2037 }
2038
2039 static void btrfs_interface_exit(void)
2040 {
2041 if (misc_deregister(&btrfs_misc) < 0)
2042 printk(KERN_INFO "BTRFS: misc_deregister failed for control device\n");
2043 }
2044
2045 static void btrfs_print_info(void)
2046 {
2047 printk(KERN_INFO "Btrfs loaded"
2048 #ifdef CONFIG_BTRFS_DEBUG
2049 ", debug=on"
2050 #endif
2051 #ifdef CONFIG_BTRFS_ASSERT
2052 ", assert=on"
2053 #endif
2054 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2055 ", integrity-checker=on"
2056 #endif
2057 "\n");
2058 }
2059
2060 static int btrfs_run_sanity_tests(void)
2061 {
2062 int ret;
2063
2064 ret = btrfs_init_test_fs();
2065 if (ret)
2066 return ret;
2067
2068 ret = btrfs_test_free_space_cache();
2069 if (ret)
2070 goto out;
2071 ret = btrfs_test_extent_buffer_operations();
2072 if (ret)
2073 goto out;
2074 ret = btrfs_test_extent_io();
2075 if (ret)
2076 goto out;
2077 ret = btrfs_test_inodes();
2078 if (ret)
2079 goto out;
2080 ret = btrfs_test_qgroups();
2081 out:
2082 btrfs_destroy_test_fs();
2083 return ret;
2084 }
2085
2086 static int __init init_btrfs_fs(void)
2087 {
2088 int err;
2089
2090 err = btrfs_hash_init();
2091 if (err)
2092 return err;
2093
2094 btrfs_props_init();
2095
2096 err = btrfs_init_sysfs();
2097 if (err)
2098 goto free_hash;
2099
2100 btrfs_init_compress();
2101
2102 err = btrfs_init_cachep();
2103 if (err)
2104 goto free_compress;
2105
2106 err = extent_io_init();
2107 if (err)
2108 goto free_cachep;
2109
2110 err = extent_map_init();
2111 if (err)
2112 goto free_extent_io;
2113
2114 err = ordered_data_init();
2115 if (err)
2116 goto free_extent_map;
2117
2118 err = btrfs_delayed_inode_init();
2119 if (err)
2120 goto free_ordered_data;
2121
2122 err = btrfs_auto_defrag_init();
2123 if (err)
2124 goto free_delayed_inode;
2125
2126 err = btrfs_delayed_ref_init();
2127 if (err)
2128 goto free_auto_defrag;
2129
2130 err = btrfs_prelim_ref_init();
2131 if (err)
2132 goto free_delayed_ref;
2133
2134 err = btrfs_end_io_wq_init();
2135 if (err)
2136 goto free_prelim_ref;
2137
2138 err = btrfs_interface_init();
2139 if (err)
2140 goto free_end_io_wq;
2141
2142 btrfs_init_lockdep();
2143
2144 btrfs_print_info();
2145
2146 err = btrfs_run_sanity_tests();
2147 if (err)
2148 goto unregister_ioctl;
2149
2150 err = register_filesystem(&btrfs_fs_type);
2151 if (err)
2152 goto unregister_ioctl;
2153
2154 return 0;
2155
2156 unregister_ioctl:
2157 btrfs_interface_exit();
2158 free_end_io_wq:
2159 btrfs_end_io_wq_exit();
2160 free_prelim_ref:
2161 btrfs_prelim_ref_exit();
2162 free_delayed_ref:
2163 btrfs_delayed_ref_exit();
2164 free_auto_defrag:
2165 btrfs_auto_defrag_exit();
2166 free_delayed_inode:
2167 btrfs_delayed_inode_exit();
2168 free_ordered_data:
2169 ordered_data_exit();
2170 free_extent_map:
2171 extent_map_exit();
2172 free_extent_io:
2173 extent_io_exit();
2174 free_cachep:
2175 btrfs_destroy_cachep();
2176 free_compress:
2177 btrfs_exit_compress();
2178 btrfs_exit_sysfs();
2179 free_hash:
2180 btrfs_hash_exit();
2181 return err;
2182 }
2183
2184 static void __exit exit_btrfs_fs(void)
2185 {
2186 btrfs_destroy_cachep();
2187 btrfs_delayed_ref_exit();
2188 btrfs_auto_defrag_exit();
2189 btrfs_delayed_inode_exit();
2190 btrfs_prelim_ref_exit();
2191 ordered_data_exit();
2192 extent_map_exit();
2193 extent_io_exit();
2194 btrfs_interface_exit();
2195 btrfs_end_io_wq_exit();
2196 unregister_filesystem(&btrfs_fs_type);
2197 btrfs_exit_sysfs();
2198 btrfs_cleanup_fs_uuids();
2199 btrfs_exit_compress();
2200 btrfs_hash_exit();
2201 }
2202
2203 late_initcall(init_btrfs_fs);
2204 module_exit(exit_btrfs_fs)
2205
2206 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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