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3c72eea1271463772d5c2861f782d07d7da1c390
[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 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
139 unsigned int line, int errno, const char *fmt, ...)
140 {
141 struct super_block *sb = fs_info->sb;
142 const char *errstr;
143
144 /*
145 * Special case: if the error is EROFS, and we're already
146 * under MS_RDONLY, then it is safe here.
147 */
148 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
149 return;
150
151 errstr = btrfs_decode_error(errno);
152 if (fmt) {
153 struct va_format vaf;
154 va_list args;
155
156 va_start(args, fmt);
157 vaf.fmt = fmt;
158 vaf.va = &args;
159
160 printk(KERN_CRIT
161 "BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
162 sb->s_id, function, line, errno, errstr, &vaf);
163 va_end(args);
164 } else {
165 printk(KERN_CRIT "BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
166 sb->s_id, function, line, errno, errstr);
167 }
168
169 /* Don't go through full error handling during mount */
170 save_error_info(fs_info);
171 if (sb->s_flags & MS_BORN)
172 btrfs_handle_error(fs_info);
173 }
174
175 static const char * const logtypes[] = {
176 "emergency",
177 "alert",
178 "critical",
179 "error",
180 "warning",
181 "notice",
182 "info",
183 "debug",
184 };
185
186 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
187 {
188 struct super_block *sb = fs_info->sb;
189 char lvl[4];
190 struct va_format vaf;
191 va_list args;
192 const char *type = logtypes[4];
193 int kern_level;
194
195 va_start(args, fmt);
196
197 kern_level = printk_get_level(fmt);
198 if (kern_level) {
199 size_t size = printk_skip_level(fmt) - fmt;
200 memcpy(lvl, fmt, size);
201 lvl[size] = '\0';
202 fmt += size;
203 type = logtypes[kern_level - '0'];
204 } else
205 *lvl = '\0';
206
207 vaf.fmt = fmt;
208 vaf.va = &args;
209
210 printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
211
212 va_end(args);
213 }
214
215 #else
216
217 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
218 unsigned int line, int errno, const char *fmt, ...)
219 {
220 struct super_block *sb = fs_info->sb;
221
222 /*
223 * Special case: if the error is EROFS, and we're already
224 * under MS_RDONLY, then it is safe here.
225 */
226 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
227 return;
228
229 /* Don't go through full error handling during mount */
230 if (sb->s_flags & MS_BORN) {
231 save_error_info(fs_info);
232 btrfs_handle_error(fs_info);
233 }
234 }
235 #endif
236
237 /*
238 * We only mark the transaction aborted and then set the file system read-only.
239 * This will prevent new transactions from starting or trying to join this
240 * one.
241 *
242 * This means that error recovery at the call site is limited to freeing
243 * any local memory allocations and passing the error code up without
244 * further cleanup. The transaction should complete as it normally would
245 * in the call path but will return -EIO.
246 *
247 * We'll complete the cleanup in btrfs_end_transaction and
248 * btrfs_commit_transaction.
249 */
250 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
251 struct btrfs_root *root, const char *function,
252 unsigned int line, int errno)
253 {
254 trans->aborted = errno;
255 /* Nothing used. The other threads that have joined this
256 * transaction may be able to continue. */
257 if (!trans->blocks_used && list_empty(&trans->new_bgs)) {
258 const char *errstr;
259
260 errstr = btrfs_decode_error(errno);
261 btrfs_warn(root->fs_info,
262 "%s:%d: Aborting unused transaction(%s).",
263 function, line, errstr);
264 return;
265 }
266 ACCESS_ONCE(trans->transaction->aborted) = errno;
267 /* Wake up anybody who may be waiting on this transaction */
268 wake_up(&root->fs_info->transaction_wait);
269 wake_up(&root->fs_info->transaction_blocked_wait);
270 __btrfs_std_error(root->fs_info, function, line, errno, NULL);
271 }
272 /*
273 * __btrfs_panic decodes unexpected, fatal errors from the caller,
274 * issues an alert, and either panics or BUGs, depending on mount options.
275 */
276 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
277 unsigned int line, int errno, const char *fmt, ...)
278 {
279 char *s_id = "<unknown>";
280 const char *errstr;
281 struct va_format vaf = { .fmt = fmt };
282 va_list args;
283
284 if (fs_info)
285 s_id = fs_info->sb->s_id;
286
287 va_start(args, fmt);
288 vaf.va = &args;
289
290 errstr = btrfs_decode_error(errno);
291 if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
292 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
293 s_id, function, line, &vaf, errno, errstr);
294
295 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
296 function, line, &vaf, errno, errstr);
297 va_end(args);
298 /* Caller calls BUG() */
299 }
300
301 static void btrfs_put_super(struct super_block *sb)
302 {
303 close_ctree(btrfs_sb(sb)->tree_root);
304 }
305
306 enum {
307 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
308 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
309 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
310 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
311 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
312 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
313 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
314 Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
315 Opt_check_integrity, Opt_check_integrity_including_extent_data,
316 Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree,
317 Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard,
318 Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow,
319 Opt_datasum, Opt_treelog, Opt_noinode_cache,
320 Opt_err,
321 };
322
323 static match_table_t tokens = {
324 {Opt_degraded, "degraded"},
325 {Opt_subvol, "subvol=%s"},
326 {Opt_subvolid, "subvolid=%s"},
327 {Opt_device, "device=%s"},
328 {Opt_nodatasum, "nodatasum"},
329 {Opt_datasum, "datasum"},
330 {Opt_nodatacow, "nodatacow"},
331 {Opt_datacow, "datacow"},
332 {Opt_nobarrier, "nobarrier"},
333 {Opt_barrier, "barrier"},
334 {Opt_max_inline, "max_inline=%s"},
335 {Opt_alloc_start, "alloc_start=%s"},
336 {Opt_thread_pool, "thread_pool=%d"},
337 {Opt_compress, "compress"},
338 {Opt_compress_type, "compress=%s"},
339 {Opt_compress_force, "compress-force"},
340 {Opt_compress_force_type, "compress-force=%s"},
341 {Opt_ssd, "ssd"},
342 {Opt_ssd_spread, "ssd_spread"},
343 {Opt_nossd, "nossd"},
344 {Opt_acl, "acl"},
345 {Opt_noacl, "noacl"},
346 {Opt_notreelog, "notreelog"},
347 {Opt_treelog, "treelog"},
348 {Opt_flushoncommit, "flushoncommit"},
349 {Opt_noflushoncommit, "noflushoncommit"},
350 {Opt_ratio, "metadata_ratio=%d"},
351 {Opt_discard, "discard"},
352 {Opt_nodiscard, "nodiscard"},
353 {Opt_space_cache, "space_cache"},
354 {Opt_clear_cache, "clear_cache"},
355 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
356 {Opt_enospc_debug, "enospc_debug"},
357 {Opt_noenospc_debug, "noenospc_debug"},
358 {Opt_subvolrootid, "subvolrootid=%d"},
359 {Opt_defrag, "autodefrag"},
360 {Opt_nodefrag, "noautodefrag"},
361 {Opt_inode_cache, "inode_cache"},
362 {Opt_noinode_cache, "noinode_cache"},
363 {Opt_no_space_cache, "nospace_cache"},
364 {Opt_recovery, "recovery"},
365 {Opt_skip_balance, "skip_balance"},
366 {Opt_check_integrity, "check_int"},
367 {Opt_check_integrity_including_extent_data, "check_int_data"},
368 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
369 {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
370 {Opt_fatal_errors, "fatal_errors=%s"},
371 {Opt_commit_interval, "commit=%d"},
372 {Opt_err, NULL},
373 };
374
375 /*
376 * Regular mount options parser. Everything that is needed only when
377 * reading in a new superblock is parsed here.
378 * XXX JDM: This needs to be cleaned up for remount.
379 */
380 int btrfs_parse_options(struct btrfs_root *root, char *options)
381 {
382 struct btrfs_fs_info *info = root->fs_info;
383 substring_t args[MAX_OPT_ARGS];
384 char *p, *num, *orig = NULL;
385 u64 cache_gen;
386 int intarg;
387 int ret = 0;
388 char *compress_type;
389 bool compress_force = false;
390
391 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
392 if (cache_gen)
393 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
394
395 if (!options)
396 goto out;
397
398 /*
399 * strsep changes the string, duplicate it because parse_options
400 * gets called twice
401 */
402 options = kstrdup(options, GFP_NOFS);
403 if (!options)
404 return -ENOMEM;
405
406 orig = options;
407
408 while ((p = strsep(&options, ",")) != NULL) {
409 int token;
410 if (!*p)
411 continue;
412
413 token = match_token(p, tokens, args);
414 switch (token) {
415 case Opt_degraded:
416 btrfs_info(root->fs_info, "allowing degraded mounts");
417 btrfs_set_opt(info->mount_opt, DEGRADED);
418 break;
419 case Opt_subvol:
420 case Opt_subvolid:
421 case Opt_subvolrootid:
422 case Opt_device:
423 /*
424 * These are parsed by btrfs_parse_early_options
425 * and can be happily ignored here.
426 */
427 break;
428 case Opt_nodatasum:
429 btrfs_set_and_info(root, NODATASUM,
430 "setting nodatasum");
431 break;
432 case Opt_datasum:
433 if (btrfs_test_opt(root, NODATASUM)) {
434 if (btrfs_test_opt(root, NODATACOW))
435 btrfs_info(root->fs_info, "setting datasum, datacow enabled");
436 else
437 btrfs_info(root->fs_info, "setting datasum");
438 }
439 btrfs_clear_opt(info->mount_opt, NODATACOW);
440 btrfs_clear_opt(info->mount_opt, NODATASUM);
441 break;
442 case Opt_nodatacow:
443 if (!btrfs_test_opt(root, NODATACOW)) {
444 if (!btrfs_test_opt(root, COMPRESS) ||
445 !btrfs_test_opt(root, FORCE_COMPRESS)) {
446 btrfs_info(root->fs_info,
447 "setting nodatacow, compression disabled");
448 } else {
449 btrfs_info(root->fs_info, "setting nodatacow");
450 }
451 }
452 btrfs_clear_opt(info->mount_opt, COMPRESS);
453 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
454 btrfs_set_opt(info->mount_opt, NODATACOW);
455 btrfs_set_opt(info->mount_opt, NODATASUM);
456 break;
457 case Opt_datacow:
458 btrfs_clear_and_info(root, NODATACOW,
459 "setting datacow");
460 break;
461 case Opt_compress_force:
462 case Opt_compress_force_type:
463 compress_force = true;
464 /* Fallthrough */
465 case Opt_compress:
466 case Opt_compress_type:
467 if (token == Opt_compress ||
468 token == Opt_compress_force ||
469 strcmp(args[0].from, "zlib") == 0) {
470 compress_type = "zlib";
471 info->compress_type = BTRFS_COMPRESS_ZLIB;
472 btrfs_set_opt(info->mount_opt, COMPRESS);
473 btrfs_clear_opt(info->mount_opt, NODATACOW);
474 btrfs_clear_opt(info->mount_opt, NODATASUM);
475 } else if (strcmp(args[0].from, "lzo") == 0) {
476 compress_type = "lzo";
477 info->compress_type = BTRFS_COMPRESS_LZO;
478 btrfs_set_opt(info->mount_opt, COMPRESS);
479 btrfs_clear_opt(info->mount_opt, NODATACOW);
480 btrfs_clear_opt(info->mount_opt, NODATASUM);
481 btrfs_set_fs_incompat(info, COMPRESS_LZO);
482 } else if (strncmp(args[0].from, "no", 2) == 0) {
483 compress_type = "no";
484 btrfs_clear_opt(info->mount_opt, COMPRESS);
485 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
486 compress_force = false;
487 } else {
488 ret = -EINVAL;
489 goto out;
490 }
491
492 if (compress_force) {
493 btrfs_set_and_info(root, FORCE_COMPRESS,
494 "force %s compression",
495 compress_type);
496 } else {
497 if (!btrfs_test_opt(root, COMPRESS))
498 btrfs_info(root->fs_info,
499 "btrfs: use %s compression",
500 compress_type);
501 /*
502 * If we remount from compress-force=xxx to
503 * compress=xxx, we need clear FORCE_COMPRESS
504 * flag, otherwise, there is no way for users
505 * to disable forcible compression separately.
506 */
507 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
508 }
509 break;
510 case Opt_ssd:
511 btrfs_set_and_info(root, SSD,
512 "use ssd allocation scheme");
513 break;
514 case Opt_ssd_spread:
515 btrfs_set_and_info(root, SSD_SPREAD,
516 "use spread ssd allocation scheme");
517 btrfs_set_opt(info->mount_opt, SSD);
518 break;
519 case Opt_nossd:
520 btrfs_set_and_info(root, NOSSD,
521 "not using ssd allocation scheme");
522 btrfs_clear_opt(info->mount_opt, SSD);
523 break;
524 case Opt_barrier:
525 btrfs_clear_and_info(root, NOBARRIER,
526 "turning on barriers");
527 break;
528 case Opt_nobarrier:
529 btrfs_set_and_info(root, NOBARRIER,
530 "turning off barriers");
531 break;
532 case Opt_thread_pool:
533 ret = match_int(&args[0], &intarg);
534 if (ret) {
535 goto out;
536 } else if (intarg > 0) {
537 info->thread_pool_size = intarg;
538 } else {
539 ret = -EINVAL;
540 goto out;
541 }
542 break;
543 case Opt_max_inline:
544 num = match_strdup(&args[0]);
545 if (num) {
546 info->max_inline = memparse(num, NULL);
547 kfree(num);
548
549 if (info->max_inline) {
550 info->max_inline = min_t(u64,
551 info->max_inline,
552 root->sectorsize);
553 }
554 btrfs_info(root->fs_info, "max_inline at %llu",
555 info->max_inline);
556 } else {
557 ret = -ENOMEM;
558 goto out;
559 }
560 break;
561 case Opt_alloc_start:
562 num = match_strdup(&args[0]);
563 if (num) {
564 mutex_lock(&info->chunk_mutex);
565 info->alloc_start = memparse(num, NULL);
566 mutex_unlock(&info->chunk_mutex);
567 kfree(num);
568 btrfs_info(root->fs_info, "allocations start at %llu",
569 info->alloc_start);
570 } else {
571 ret = -ENOMEM;
572 goto out;
573 }
574 break;
575 case Opt_acl:
576 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
577 root->fs_info->sb->s_flags |= MS_POSIXACL;
578 break;
579 #else
580 btrfs_err(root->fs_info,
581 "support for ACL not compiled in!");
582 ret = -EINVAL;
583 goto out;
584 #endif
585 case Opt_noacl:
586 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
587 break;
588 case Opt_notreelog:
589 btrfs_set_and_info(root, NOTREELOG,
590 "disabling tree log");
591 break;
592 case Opt_treelog:
593 btrfs_clear_and_info(root, NOTREELOG,
594 "enabling tree log");
595 break;
596 case Opt_flushoncommit:
597 btrfs_set_and_info(root, FLUSHONCOMMIT,
598 "turning on flush-on-commit");
599 break;
600 case Opt_noflushoncommit:
601 btrfs_clear_and_info(root, FLUSHONCOMMIT,
602 "turning off flush-on-commit");
603 break;
604 case Opt_ratio:
605 ret = match_int(&args[0], &intarg);
606 if (ret) {
607 goto out;
608 } else if (intarg >= 0) {
609 info->metadata_ratio = intarg;
610 btrfs_info(root->fs_info, "metadata ratio %d",
611 info->metadata_ratio);
612 } else {
613 ret = -EINVAL;
614 goto out;
615 }
616 break;
617 case Opt_discard:
618 btrfs_set_and_info(root, DISCARD,
619 "turning on discard");
620 break;
621 case Opt_nodiscard:
622 btrfs_clear_and_info(root, DISCARD,
623 "turning off discard");
624 break;
625 case Opt_space_cache:
626 btrfs_set_and_info(root, SPACE_CACHE,
627 "enabling disk space caching");
628 break;
629 case Opt_rescan_uuid_tree:
630 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
631 break;
632 case Opt_no_space_cache:
633 btrfs_clear_and_info(root, SPACE_CACHE,
634 "disabling disk space caching");
635 break;
636 case Opt_inode_cache:
637 btrfs_set_pending_and_info(info, INODE_MAP_CACHE,
638 "enabling inode map caching");
639 break;
640 case Opt_noinode_cache:
641 btrfs_clear_pending_and_info(info, INODE_MAP_CACHE,
642 "disabling inode map caching");
643 break;
644 case Opt_clear_cache:
645 btrfs_set_and_info(root, CLEAR_CACHE,
646 "force clearing of disk cache");
647 break;
648 case Opt_user_subvol_rm_allowed:
649 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
650 break;
651 case Opt_enospc_debug:
652 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
653 break;
654 case Opt_noenospc_debug:
655 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
656 break;
657 case Opt_defrag:
658 btrfs_set_and_info(root, AUTO_DEFRAG,
659 "enabling auto defrag");
660 break;
661 case Opt_nodefrag:
662 btrfs_clear_and_info(root, AUTO_DEFRAG,
663 "disabling auto defrag");
664 break;
665 case Opt_recovery:
666 btrfs_info(root->fs_info, "enabling auto recovery");
667 btrfs_set_opt(info->mount_opt, RECOVERY);
668 break;
669 case Opt_skip_balance:
670 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
671 break;
672 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
673 case Opt_check_integrity_including_extent_data:
674 btrfs_info(root->fs_info,
675 "enabling check integrity including extent data");
676 btrfs_set_opt(info->mount_opt,
677 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
678 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
679 break;
680 case Opt_check_integrity:
681 btrfs_info(root->fs_info, "enabling check integrity");
682 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
683 break;
684 case Opt_check_integrity_print_mask:
685 ret = match_int(&args[0], &intarg);
686 if (ret) {
687 goto out;
688 } else if (intarg >= 0) {
689 info->check_integrity_print_mask = intarg;
690 btrfs_info(root->fs_info, "check_integrity_print_mask 0x%x",
691 info->check_integrity_print_mask);
692 } else {
693 ret = -EINVAL;
694 goto out;
695 }
696 break;
697 #else
698 case Opt_check_integrity_including_extent_data:
699 case Opt_check_integrity:
700 case Opt_check_integrity_print_mask:
701 btrfs_err(root->fs_info,
702 "support for check_integrity* not compiled in!");
703 ret = -EINVAL;
704 goto out;
705 #endif
706 case Opt_fatal_errors:
707 if (strcmp(args[0].from, "panic") == 0)
708 btrfs_set_opt(info->mount_opt,
709 PANIC_ON_FATAL_ERROR);
710 else if (strcmp(args[0].from, "bug") == 0)
711 btrfs_clear_opt(info->mount_opt,
712 PANIC_ON_FATAL_ERROR);
713 else {
714 ret = -EINVAL;
715 goto out;
716 }
717 break;
718 case Opt_commit_interval:
719 intarg = 0;
720 ret = match_int(&args[0], &intarg);
721 if (ret < 0) {
722 btrfs_err(root->fs_info, "invalid commit interval");
723 ret = -EINVAL;
724 goto out;
725 }
726 if (intarg > 0) {
727 if (intarg > 300) {
728 btrfs_warn(root->fs_info, "excessive commit interval %d",
729 intarg);
730 }
731 info->commit_interval = intarg;
732 } else {
733 btrfs_info(root->fs_info, "using default commit interval %ds",
734 BTRFS_DEFAULT_COMMIT_INTERVAL);
735 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
736 }
737 break;
738 case Opt_err:
739 btrfs_info(root->fs_info, "unrecognized mount option '%s'", p);
740 ret = -EINVAL;
741 goto out;
742 default:
743 break;
744 }
745 }
746 out:
747 if (!ret && btrfs_test_opt(root, SPACE_CACHE))
748 btrfs_info(root->fs_info, "disk space caching is enabled");
749 kfree(orig);
750 return ret;
751 }
752
753 /*
754 * Parse mount options that are required early in the mount process.
755 *
756 * All other options will be parsed on much later in the mount process and
757 * only when we need to allocate a new super block.
758 */
759 static int btrfs_parse_early_options(const char *options, fmode_t flags,
760 void *holder, char **subvol_name, u64 *subvol_objectid,
761 struct btrfs_fs_devices **fs_devices)
762 {
763 substring_t args[MAX_OPT_ARGS];
764 char *device_name, *opts, *orig, *p;
765 char *num = NULL;
766 int error = 0;
767
768 if (!options)
769 return 0;
770
771 /*
772 * strsep changes the string, duplicate it because parse_options
773 * gets called twice
774 */
775 opts = kstrdup(options, GFP_KERNEL);
776 if (!opts)
777 return -ENOMEM;
778 orig = opts;
779
780 while ((p = strsep(&opts, ",")) != NULL) {
781 int token;
782 if (!*p)
783 continue;
784
785 token = match_token(p, tokens, args);
786 switch (token) {
787 case Opt_subvol:
788 kfree(*subvol_name);
789 *subvol_name = match_strdup(&args[0]);
790 if (!*subvol_name) {
791 error = -ENOMEM;
792 goto out;
793 }
794 break;
795 case Opt_subvolid:
796 num = match_strdup(&args[0]);
797 if (num) {
798 *subvol_objectid = memparse(num, NULL);
799 kfree(num);
800 /* we want the original fs_tree */
801 if (!*subvol_objectid)
802 *subvol_objectid =
803 BTRFS_FS_TREE_OBJECTID;
804 } else {
805 error = -EINVAL;
806 goto out;
807 }
808 break;
809 case Opt_subvolrootid:
810 printk(KERN_WARNING
811 "BTRFS: 'subvolrootid' mount option is deprecated and has "
812 "no effect\n");
813 break;
814 case Opt_device:
815 device_name = match_strdup(&args[0]);
816 if (!device_name) {
817 error = -ENOMEM;
818 goto out;
819 }
820 error = btrfs_scan_one_device(device_name,
821 flags, holder, fs_devices);
822 kfree(device_name);
823 if (error)
824 goto out;
825 break;
826 default:
827 break;
828 }
829 }
830
831 out:
832 kfree(orig);
833 return error;
834 }
835
836 static struct dentry *get_default_root(struct super_block *sb,
837 u64 subvol_objectid)
838 {
839 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
840 struct btrfs_root *root = fs_info->tree_root;
841 struct btrfs_root *new_root;
842 struct btrfs_dir_item *di;
843 struct btrfs_path *path;
844 struct btrfs_key location;
845 struct inode *inode;
846 u64 dir_id;
847 int new = 0;
848
849 /*
850 * We have a specific subvol we want to mount, just setup location and
851 * go look up the root.
852 */
853 if (subvol_objectid) {
854 location.objectid = subvol_objectid;
855 location.type = BTRFS_ROOT_ITEM_KEY;
856 location.offset = (u64)-1;
857 goto find_root;
858 }
859
860 path = btrfs_alloc_path();
861 if (!path)
862 return ERR_PTR(-ENOMEM);
863 path->leave_spinning = 1;
864
865 /*
866 * Find the "default" dir item which points to the root item that we
867 * will mount by default if we haven't been given a specific subvolume
868 * to mount.
869 */
870 dir_id = btrfs_super_root_dir(fs_info->super_copy);
871 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
872 if (IS_ERR(di)) {
873 btrfs_free_path(path);
874 return ERR_CAST(di);
875 }
876 if (!di) {
877 /*
878 * Ok the default dir item isn't there. This is weird since
879 * it's always been there, but don't freak out, just try and
880 * mount to root most subvolume.
881 */
882 btrfs_free_path(path);
883 dir_id = BTRFS_FIRST_FREE_OBJECTID;
884 new_root = fs_info->fs_root;
885 goto setup_root;
886 }
887
888 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
889 btrfs_free_path(path);
890
891 find_root:
892 new_root = btrfs_read_fs_root_no_name(fs_info, &location);
893 if (IS_ERR(new_root))
894 return ERR_CAST(new_root);
895
896 if (!(sb->s_flags & MS_RDONLY)) {
897 int ret;
898 down_read(&fs_info->cleanup_work_sem);
899 ret = btrfs_orphan_cleanup(new_root);
900 up_read(&fs_info->cleanup_work_sem);
901 if (ret)
902 return ERR_PTR(ret);
903 }
904
905 dir_id = btrfs_root_dirid(&new_root->root_item);
906 setup_root:
907 location.objectid = dir_id;
908 location.type = BTRFS_INODE_ITEM_KEY;
909 location.offset = 0;
910
911 inode = btrfs_iget(sb, &location, new_root, &new);
912 if (IS_ERR(inode))
913 return ERR_CAST(inode);
914
915 /*
916 * If we're just mounting the root most subvol put the inode and return
917 * a reference to the dentry. We will have already gotten a reference
918 * to the inode in btrfs_fill_super so we're good to go.
919 */
920 if (!new && d_inode(sb->s_root) == inode) {
921 iput(inode);
922 return dget(sb->s_root);
923 }
924
925 return d_obtain_root(inode);
926 }
927
928 static int btrfs_fill_super(struct super_block *sb,
929 struct btrfs_fs_devices *fs_devices,
930 void *data, int silent)
931 {
932 struct inode *inode;
933 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
934 struct btrfs_key key;
935 int err;
936
937 sb->s_maxbytes = MAX_LFS_FILESIZE;
938 sb->s_magic = BTRFS_SUPER_MAGIC;
939 sb->s_op = &btrfs_super_ops;
940 sb->s_d_op = &btrfs_dentry_operations;
941 sb->s_export_op = &btrfs_export_ops;
942 sb->s_xattr = btrfs_xattr_handlers;
943 sb->s_time_gran = 1;
944 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
945 sb->s_flags |= MS_POSIXACL;
946 #endif
947 sb->s_flags |= MS_I_VERSION;
948 err = open_ctree(sb, fs_devices, (char *)data);
949 if (err) {
950 printk(KERN_ERR "BTRFS: open_ctree failed\n");
951 return err;
952 }
953
954 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
955 key.type = BTRFS_INODE_ITEM_KEY;
956 key.offset = 0;
957 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
958 if (IS_ERR(inode)) {
959 err = PTR_ERR(inode);
960 goto fail_close;
961 }
962
963 sb->s_root = d_make_root(inode);
964 if (!sb->s_root) {
965 err = -ENOMEM;
966 goto fail_close;
967 }
968
969 save_mount_options(sb, data);
970 cleancache_init_fs(sb);
971 sb->s_flags |= MS_ACTIVE;
972 return 0;
973
974 fail_close:
975 close_ctree(fs_info->tree_root);
976 return err;
977 }
978
979 int btrfs_sync_fs(struct super_block *sb, int wait)
980 {
981 struct btrfs_trans_handle *trans;
982 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
983 struct btrfs_root *root = fs_info->tree_root;
984
985 trace_btrfs_sync_fs(wait);
986
987 if (!wait) {
988 filemap_flush(fs_info->btree_inode->i_mapping);
989 return 0;
990 }
991
992 btrfs_wait_ordered_roots(fs_info, -1);
993
994 trans = btrfs_attach_transaction_barrier(root);
995 if (IS_ERR(trans)) {
996 /* no transaction, don't bother */
997 if (PTR_ERR(trans) == -ENOENT) {
998 /*
999 * Exit unless we have some pending changes
1000 * that need to go through commit
1001 */
1002 if (fs_info->pending_changes == 0)
1003 return 0;
1004 /*
1005 * A non-blocking test if the fs is frozen. We must not
1006 * start a new transaction here otherwise a deadlock
1007 * happens. The pending operations are delayed to the
1008 * next commit after thawing.
1009 */
1010 if (__sb_start_write(sb, SB_FREEZE_WRITE, false))
1011 __sb_end_write(sb, SB_FREEZE_WRITE);
1012 else
1013 return 0;
1014 trans = btrfs_start_transaction(root, 0);
1015 }
1016 if (IS_ERR(trans))
1017 return PTR_ERR(trans);
1018 }
1019 return btrfs_commit_transaction(trans, root);
1020 }
1021
1022 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
1023 {
1024 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
1025 struct btrfs_root *root = info->tree_root;
1026 char *compress_type;
1027
1028 if (btrfs_test_opt(root, DEGRADED))
1029 seq_puts(seq, ",degraded");
1030 if (btrfs_test_opt(root, NODATASUM))
1031 seq_puts(seq, ",nodatasum");
1032 if (btrfs_test_opt(root, NODATACOW))
1033 seq_puts(seq, ",nodatacow");
1034 if (btrfs_test_opt(root, NOBARRIER))
1035 seq_puts(seq, ",nobarrier");
1036 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE)
1037 seq_printf(seq, ",max_inline=%llu", info->max_inline);
1038 if (info->alloc_start != 0)
1039 seq_printf(seq, ",alloc_start=%llu", info->alloc_start);
1040 if (info->thread_pool_size != min_t(unsigned long,
1041 num_online_cpus() + 2, 8))
1042 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
1043 if (btrfs_test_opt(root, COMPRESS)) {
1044 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
1045 compress_type = "zlib";
1046 else
1047 compress_type = "lzo";
1048 if (btrfs_test_opt(root, FORCE_COMPRESS))
1049 seq_printf(seq, ",compress-force=%s", compress_type);
1050 else
1051 seq_printf(seq, ",compress=%s", compress_type);
1052 }
1053 if (btrfs_test_opt(root, NOSSD))
1054 seq_puts(seq, ",nossd");
1055 if (btrfs_test_opt(root, SSD_SPREAD))
1056 seq_puts(seq, ",ssd_spread");
1057 else if (btrfs_test_opt(root, SSD))
1058 seq_puts(seq, ",ssd");
1059 if (btrfs_test_opt(root, NOTREELOG))
1060 seq_puts(seq, ",notreelog");
1061 if (btrfs_test_opt(root, FLUSHONCOMMIT))
1062 seq_puts(seq, ",flushoncommit");
1063 if (btrfs_test_opt(root, DISCARD))
1064 seq_puts(seq, ",discard");
1065 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
1066 seq_puts(seq, ",noacl");
1067 if (btrfs_test_opt(root, SPACE_CACHE))
1068 seq_puts(seq, ",space_cache");
1069 else
1070 seq_puts(seq, ",nospace_cache");
1071 if (btrfs_test_opt(root, RESCAN_UUID_TREE))
1072 seq_puts(seq, ",rescan_uuid_tree");
1073 if (btrfs_test_opt(root, CLEAR_CACHE))
1074 seq_puts(seq, ",clear_cache");
1075 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1076 seq_puts(seq, ",user_subvol_rm_allowed");
1077 if (btrfs_test_opt(root, ENOSPC_DEBUG))
1078 seq_puts(seq, ",enospc_debug");
1079 if (btrfs_test_opt(root, AUTO_DEFRAG))
1080 seq_puts(seq, ",autodefrag");
1081 if (btrfs_test_opt(root, INODE_MAP_CACHE))
1082 seq_puts(seq, ",inode_cache");
1083 if (btrfs_test_opt(root, SKIP_BALANCE))
1084 seq_puts(seq, ",skip_balance");
1085 if (btrfs_test_opt(root, RECOVERY))
1086 seq_puts(seq, ",recovery");
1087 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1088 if (btrfs_test_opt(root, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1089 seq_puts(seq, ",check_int_data");
1090 else if (btrfs_test_opt(root, CHECK_INTEGRITY))
1091 seq_puts(seq, ",check_int");
1092 if (info->check_integrity_print_mask)
1093 seq_printf(seq, ",check_int_print_mask=%d",
1094 info->check_integrity_print_mask);
1095 #endif
1096 if (info->metadata_ratio)
1097 seq_printf(seq, ",metadata_ratio=%d",
1098 info->metadata_ratio);
1099 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
1100 seq_puts(seq, ",fatal_errors=panic");
1101 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1102 seq_printf(seq, ",commit=%d", info->commit_interval);
1103 return 0;
1104 }
1105
1106 static int btrfs_test_super(struct super_block *s, void *data)
1107 {
1108 struct btrfs_fs_info *p = data;
1109 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1110
1111 return fs_info->fs_devices == p->fs_devices;
1112 }
1113
1114 static int btrfs_set_super(struct super_block *s, void *data)
1115 {
1116 int err = set_anon_super(s, data);
1117 if (!err)
1118 s->s_fs_info = data;
1119 return err;
1120 }
1121
1122 /*
1123 * subvolumes are identified by ino 256
1124 */
1125 static inline int is_subvolume_inode(struct inode *inode)
1126 {
1127 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1128 return 1;
1129 return 0;
1130 }
1131
1132 /*
1133 * This will strip out the subvol=%s argument for an argument string and add
1134 * subvolid=0 to make sure we get the actual tree root for path walking to the
1135 * subvol we want.
1136 */
1137 static char *setup_root_args(char *args)
1138 {
1139 unsigned len = strlen(args) + 2 + 1;
1140 char *src, *dst, *buf;
1141
1142 /*
1143 * We need the same args as before, but with this substitution:
1144 * s!subvol=[^,]+!subvolid=0!
1145 *
1146 * Since the replacement string is up to 2 bytes longer than the
1147 * original, allocate strlen(args) + 2 + 1 bytes.
1148 */
1149
1150 src = strstr(args, "subvol=");
1151 /* This shouldn't happen, but just in case.. */
1152 if (!src)
1153 return NULL;
1154
1155 buf = dst = kmalloc(len, GFP_NOFS);
1156 if (!buf)
1157 return NULL;
1158
1159 /*
1160 * If the subvol= arg is not at the start of the string,
1161 * copy whatever precedes it into buf.
1162 */
1163 if (src != args) {
1164 *src++ = '\0';
1165 strcpy(buf, args);
1166 dst += strlen(args);
1167 }
1168
1169 strcpy(dst, "subvolid=0");
1170 dst += strlen("subvolid=0");
1171
1172 /*
1173 * If there is a "," after the original subvol=... string,
1174 * copy that suffix into our buffer. Otherwise, we're done.
1175 */
1176 src = strchr(src, ',');
1177 if (src)
1178 strcpy(dst, src);
1179
1180 return buf;
1181 }
1182
1183 static struct dentry *mount_subvol(const char *subvol_name, int flags,
1184 const char *device_name, char *data)
1185 {
1186 struct dentry *root;
1187 struct vfsmount *mnt;
1188 char *newargs;
1189
1190 newargs = setup_root_args(data);
1191 if (!newargs)
1192 return ERR_PTR(-ENOMEM);
1193 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
1194 newargs);
1195
1196 if (PTR_RET(mnt) == -EBUSY) {
1197 if (flags & MS_RDONLY) {
1198 mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~MS_RDONLY, device_name,
1199 newargs);
1200 } else {
1201 int r;
1202 mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY, device_name,
1203 newargs);
1204 if (IS_ERR(mnt)) {
1205 kfree(newargs);
1206 return ERR_CAST(mnt);
1207 }
1208
1209 r = btrfs_remount(mnt->mnt_sb, &flags, NULL);
1210 if (r < 0) {
1211 /* FIXME: release vfsmount mnt ??*/
1212 kfree(newargs);
1213 return ERR_PTR(r);
1214 }
1215 }
1216 }
1217
1218 kfree(newargs);
1219
1220 if (IS_ERR(mnt))
1221 return ERR_CAST(mnt);
1222
1223 root = mount_subtree(mnt, subvol_name);
1224
1225 if (!IS_ERR(root) && !is_subvolume_inode(d_inode(root))) {
1226 struct super_block *s = root->d_sb;
1227 dput(root);
1228 root = ERR_PTR(-EINVAL);
1229 deactivate_locked_super(s);
1230 printk(KERN_ERR "BTRFS: '%s' is not a valid subvolume\n",
1231 subvol_name);
1232 }
1233
1234 return root;
1235 }
1236
1237 static int parse_security_options(char *orig_opts,
1238 struct security_mnt_opts *sec_opts)
1239 {
1240 char *secdata = NULL;
1241 int ret = 0;
1242
1243 secdata = alloc_secdata();
1244 if (!secdata)
1245 return -ENOMEM;
1246 ret = security_sb_copy_data(orig_opts, secdata);
1247 if (ret) {
1248 free_secdata(secdata);
1249 return ret;
1250 }
1251 ret = security_sb_parse_opts_str(secdata, sec_opts);
1252 free_secdata(secdata);
1253 return ret;
1254 }
1255
1256 static int setup_security_options(struct btrfs_fs_info *fs_info,
1257 struct super_block *sb,
1258 struct security_mnt_opts *sec_opts)
1259 {
1260 int ret = 0;
1261
1262 /*
1263 * Call security_sb_set_mnt_opts() to check whether new sec_opts
1264 * is valid.
1265 */
1266 ret = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL);
1267 if (ret)
1268 return ret;
1269
1270 #ifdef CONFIG_SECURITY
1271 if (!fs_info->security_opts.num_mnt_opts) {
1272 /* first time security setup, copy sec_opts to fs_info */
1273 memcpy(&fs_info->security_opts, sec_opts, sizeof(*sec_opts));
1274 } else {
1275 /*
1276 * Since SELinux(the only one supports security_mnt_opts) does
1277 * NOT support changing context during remount/mount same sb,
1278 * This must be the same or part of the same security options,
1279 * just free it.
1280 */
1281 security_free_mnt_opts(sec_opts);
1282 }
1283 #endif
1284 return ret;
1285 }
1286
1287 /*
1288 * Find a superblock for the given device / mount point.
1289 *
1290 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1291 * for multiple device setup. Make sure to keep it in sync.
1292 */
1293 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1294 const char *device_name, void *data)
1295 {
1296 struct block_device *bdev = NULL;
1297 struct super_block *s;
1298 struct dentry *root;
1299 struct btrfs_fs_devices *fs_devices = NULL;
1300 struct btrfs_fs_info *fs_info = NULL;
1301 struct security_mnt_opts new_sec_opts;
1302 fmode_t mode = FMODE_READ;
1303 char *subvol_name = NULL;
1304 u64 subvol_objectid = 0;
1305 int error = 0;
1306
1307 if (!(flags & MS_RDONLY))
1308 mode |= FMODE_WRITE;
1309
1310 error = btrfs_parse_early_options(data, mode, fs_type,
1311 &subvol_name, &subvol_objectid,
1312 &fs_devices);
1313 if (error) {
1314 kfree(subvol_name);
1315 return ERR_PTR(error);
1316 }
1317
1318 if (subvol_name) {
1319 root = mount_subvol(subvol_name, flags, device_name, data);
1320 kfree(subvol_name);
1321 return root;
1322 }
1323
1324 security_init_mnt_opts(&new_sec_opts);
1325 if (data) {
1326 error = parse_security_options(data, &new_sec_opts);
1327 if (error)
1328 return ERR_PTR(error);
1329 }
1330
1331 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1332 if (error)
1333 goto error_sec_opts;
1334
1335 /*
1336 * Setup a dummy root and fs_info for test/set super. This is because
1337 * we don't actually fill this stuff out until open_ctree, but we need
1338 * it for searching for existing supers, so this lets us do that and
1339 * then open_ctree will properly initialize everything later.
1340 */
1341 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1342 if (!fs_info) {
1343 error = -ENOMEM;
1344 goto error_sec_opts;
1345 }
1346
1347 fs_info->fs_devices = fs_devices;
1348
1349 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1350 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1351 security_init_mnt_opts(&fs_info->security_opts);
1352 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1353 error = -ENOMEM;
1354 goto error_fs_info;
1355 }
1356
1357 error = btrfs_open_devices(fs_devices, mode, fs_type);
1358 if (error)
1359 goto error_fs_info;
1360
1361 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1362 error = -EACCES;
1363 goto error_close_devices;
1364 }
1365
1366 bdev = fs_devices->latest_bdev;
1367 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1368 fs_info);
1369 if (IS_ERR(s)) {
1370 error = PTR_ERR(s);
1371 goto error_close_devices;
1372 }
1373
1374 if (s->s_root) {
1375 btrfs_close_devices(fs_devices);
1376 free_fs_info(fs_info);
1377 if ((flags ^ s->s_flags) & MS_RDONLY)
1378 error = -EBUSY;
1379 } else {
1380 char b[BDEVNAME_SIZE];
1381
1382 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1383 btrfs_sb(s)->bdev_holder = fs_type;
1384 error = btrfs_fill_super(s, fs_devices, data,
1385 flags & MS_SILENT ? 1 : 0);
1386 }
1387
1388 root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1389 if (IS_ERR(root)) {
1390 deactivate_locked_super(s);
1391 error = PTR_ERR(root);
1392 goto error_sec_opts;
1393 }
1394
1395 fs_info = btrfs_sb(s);
1396 error = setup_security_options(fs_info, s, &new_sec_opts);
1397 if (error) {
1398 dput(root);
1399 deactivate_locked_super(s);
1400 goto error_sec_opts;
1401 }
1402
1403 return root;
1404
1405 error_close_devices:
1406 btrfs_close_devices(fs_devices);
1407 error_fs_info:
1408 free_fs_info(fs_info);
1409 error_sec_opts:
1410 security_free_mnt_opts(&new_sec_opts);
1411 return ERR_PTR(error);
1412 }
1413
1414 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1415 int new_pool_size, int old_pool_size)
1416 {
1417 if (new_pool_size == old_pool_size)
1418 return;
1419
1420 fs_info->thread_pool_size = new_pool_size;
1421
1422 btrfs_info(fs_info, "resize thread pool %d -> %d",
1423 old_pool_size, new_pool_size);
1424
1425 btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
1426 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
1427 btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size);
1428 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
1429 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
1430 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
1431 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
1432 new_pool_size);
1433 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
1434 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
1435 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
1436 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size);
1437 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers,
1438 new_pool_size);
1439 }
1440
1441 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1442 {
1443 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1444 }
1445
1446 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1447 unsigned long old_opts, int flags)
1448 {
1449 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1450 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1451 (flags & MS_RDONLY))) {
1452 /* wait for any defraggers to finish */
1453 wait_event(fs_info->transaction_wait,
1454 (atomic_read(&fs_info->defrag_running) == 0));
1455 if (flags & MS_RDONLY)
1456 sync_filesystem(fs_info->sb);
1457 }
1458 }
1459
1460 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1461 unsigned long old_opts)
1462 {
1463 /*
1464 * We need cleanup all defragable inodes if the autodefragment is
1465 * close or the fs is R/O.
1466 */
1467 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1468 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1469 (fs_info->sb->s_flags & MS_RDONLY))) {
1470 btrfs_cleanup_defrag_inodes(fs_info);
1471 }
1472
1473 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1474 }
1475
1476 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1477 {
1478 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1479 struct btrfs_root *root = fs_info->tree_root;
1480 unsigned old_flags = sb->s_flags;
1481 unsigned long old_opts = fs_info->mount_opt;
1482 unsigned long old_compress_type = fs_info->compress_type;
1483 u64 old_max_inline = fs_info->max_inline;
1484 u64 old_alloc_start = fs_info->alloc_start;
1485 int old_thread_pool_size = fs_info->thread_pool_size;
1486 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1487 int ret;
1488
1489 sync_filesystem(sb);
1490 btrfs_remount_prepare(fs_info);
1491
1492 if (data) {
1493 struct security_mnt_opts new_sec_opts;
1494
1495 security_init_mnt_opts(&new_sec_opts);
1496 ret = parse_security_options(data, &new_sec_opts);
1497 if (ret)
1498 goto restore;
1499 ret = setup_security_options(fs_info, sb,
1500 &new_sec_opts);
1501 if (ret) {
1502 security_free_mnt_opts(&new_sec_opts);
1503 goto restore;
1504 }
1505 }
1506
1507 ret = btrfs_parse_options(root, data);
1508 if (ret) {
1509 ret = -EINVAL;
1510 goto restore;
1511 }
1512
1513 btrfs_remount_begin(fs_info, old_opts, *flags);
1514 btrfs_resize_thread_pool(fs_info,
1515 fs_info->thread_pool_size, old_thread_pool_size);
1516
1517 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1518 goto out;
1519
1520 if (*flags & MS_RDONLY) {
1521 /*
1522 * this also happens on 'umount -rf' or on shutdown, when
1523 * the filesystem is busy.
1524 */
1525 cancel_work_sync(&fs_info->async_reclaim_work);
1526
1527 /* wait for the uuid_scan task to finish */
1528 down(&fs_info->uuid_tree_rescan_sem);
1529 /* avoid complains from lockdep et al. */
1530 up(&fs_info->uuid_tree_rescan_sem);
1531
1532 sb->s_flags |= MS_RDONLY;
1533
1534 btrfs_dev_replace_suspend_for_unmount(fs_info);
1535 btrfs_scrub_cancel(fs_info);
1536 btrfs_pause_balance(fs_info);
1537
1538 ret = btrfs_commit_super(root);
1539 if (ret)
1540 goto restore;
1541 } else {
1542 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
1543 btrfs_err(fs_info,
1544 "Remounting read-write after error is not allowed");
1545 ret = -EINVAL;
1546 goto restore;
1547 }
1548 if (fs_info->fs_devices->rw_devices == 0) {
1549 ret = -EACCES;
1550 goto restore;
1551 }
1552
1553 if (fs_info->fs_devices->missing_devices >
1554 fs_info->num_tolerated_disk_barrier_failures &&
1555 !(*flags & MS_RDONLY)) {
1556 btrfs_warn(fs_info,
1557 "too many missing devices, writeable remount is not allowed");
1558 ret = -EACCES;
1559 goto restore;
1560 }
1561
1562 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1563 ret = -EINVAL;
1564 goto restore;
1565 }
1566
1567 ret = btrfs_cleanup_fs_roots(fs_info);
1568 if (ret)
1569 goto restore;
1570
1571 /* recover relocation */
1572 mutex_lock(&fs_info->cleaner_mutex);
1573 ret = btrfs_recover_relocation(root);
1574 mutex_unlock(&fs_info->cleaner_mutex);
1575 if (ret)
1576 goto restore;
1577
1578 ret = btrfs_resume_balance_async(fs_info);
1579 if (ret)
1580 goto restore;
1581
1582 ret = btrfs_resume_dev_replace_async(fs_info);
1583 if (ret) {
1584 btrfs_warn(fs_info, "failed to resume dev_replace");
1585 goto restore;
1586 }
1587
1588 if (!fs_info->uuid_root) {
1589 btrfs_info(fs_info, "creating UUID tree");
1590 ret = btrfs_create_uuid_tree(fs_info);
1591 if (ret) {
1592 btrfs_warn(fs_info, "failed to create the UUID tree %d", ret);
1593 goto restore;
1594 }
1595 }
1596 sb->s_flags &= ~MS_RDONLY;
1597 }
1598 out:
1599 wake_up_process(fs_info->transaction_kthread);
1600 btrfs_remount_cleanup(fs_info, old_opts);
1601 return 0;
1602
1603 restore:
1604 /* We've hit an error - don't reset MS_RDONLY */
1605 if (sb->s_flags & MS_RDONLY)
1606 old_flags |= MS_RDONLY;
1607 sb->s_flags = old_flags;
1608 fs_info->mount_opt = old_opts;
1609 fs_info->compress_type = old_compress_type;
1610 fs_info->max_inline = old_max_inline;
1611 mutex_lock(&fs_info->chunk_mutex);
1612 fs_info->alloc_start = old_alloc_start;
1613 mutex_unlock(&fs_info->chunk_mutex);
1614 btrfs_resize_thread_pool(fs_info,
1615 old_thread_pool_size, fs_info->thread_pool_size);
1616 fs_info->metadata_ratio = old_metadata_ratio;
1617 btrfs_remount_cleanup(fs_info, old_opts);
1618 return ret;
1619 }
1620
1621 /* Used to sort the devices by max_avail(descending sort) */
1622 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1623 const void *dev_info2)
1624 {
1625 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1626 ((struct btrfs_device_info *)dev_info2)->max_avail)
1627 return -1;
1628 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1629 ((struct btrfs_device_info *)dev_info2)->max_avail)
1630 return 1;
1631 else
1632 return 0;
1633 }
1634
1635 /*
1636 * sort the devices by max_avail, in which max free extent size of each device
1637 * is stored.(Descending Sort)
1638 */
1639 static inline void btrfs_descending_sort_devices(
1640 struct btrfs_device_info *devices,
1641 size_t nr_devices)
1642 {
1643 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1644 btrfs_cmp_device_free_bytes, NULL);
1645 }
1646
1647 /*
1648 * The helper to calc the free space on the devices that can be used to store
1649 * file data.
1650 */
1651 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1652 {
1653 struct btrfs_fs_info *fs_info = root->fs_info;
1654 struct btrfs_device_info *devices_info;
1655 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1656 struct btrfs_device *device;
1657 u64 skip_space;
1658 u64 type;
1659 u64 avail_space;
1660 u64 used_space;
1661 u64 min_stripe_size;
1662 int min_stripes = 1, num_stripes = 1;
1663 int i = 0, nr_devices;
1664 int ret;
1665
1666 /*
1667 * We aren't under the device list lock, so this is racey-ish, but good
1668 * enough for our purposes.
1669 */
1670 nr_devices = fs_info->fs_devices->open_devices;
1671 if (!nr_devices) {
1672 smp_mb();
1673 nr_devices = fs_info->fs_devices->open_devices;
1674 ASSERT(nr_devices);
1675 if (!nr_devices) {
1676 *free_bytes = 0;
1677 return 0;
1678 }
1679 }
1680
1681 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1682 GFP_NOFS);
1683 if (!devices_info)
1684 return -ENOMEM;
1685
1686 /* calc min stripe number for data space alloction */
1687 type = btrfs_get_alloc_profile(root, 1);
1688 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1689 min_stripes = 2;
1690 num_stripes = nr_devices;
1691 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1692 min_stripes = 2;
1693 num_stripes = 2;
1694 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1695 min_stripes = 4;
1696 num_stripes = 4;
1697 }
1698
1699 if (type & BTRFS_BLOCK_GROUP_DUP)
1700 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1701 else
1702 min_stripe_size = BTRFS_STRIPE_LEN;
1703
1704 if (fs_info->alloc_start)
1705 mutex_lock(&fs_devices->device_list_mutex);
1706 rcu_read_lock();
1707 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
1708 if (!device->in_fs_metadata || !device->bdev ||
1709 device->is_tgtdev_for_dev_replace)
1710 continue;
1711
1712 if (i >= nr_devices)
1713 break;
1714
1715 avail_space = device->total_bytes - device->bytes_used;
1716
1717 /* align with stripe_len */
1718 avail_space = div_u64(avail_space, BTRFS_STRIPE_LEN);
1719 avail_space *= BTRFS_STRIPE_LEN;
1720
1721 /*
1722 * In order to avoid overwritting the superblock on the drive,
1723 * btrfs starts at an offset of at least 1MB when doing chunk
1724 * allocation.
1725 */
1726 skip_space = 1024 * 1024;
1727
1728 /* user can set the offset in fs_info->alloc_start. */
1729 if (fs_info->alloc_start &&
1730 fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1731 device->total_bytes) {
1732 rcu_read_unlock();
1733 skip_space = max(fs_info->alloc_start, skip_space);
1734
1735 /*
1736 * btrfs can not use the free space in
1737 * [0, skip_space - 1], we must subtract it from the
1738 * total. In order to implement it, we account the used
1739 * space in this range first.
1740 */
1741 ret = btrfs_account_dev_extents_size(device, 0,
1742 skip_space - 1,
1743 &used_space);
1744 if (ret) {
1745 kfree(devices_info);
1746 mutex_unlock(&fs_devices->device_list_mutex);
1747 return ret;
1748 }
1749
1750 rcu_read_lock();
1751
1752 /* calc the free space in [0, skip_space - 1] */
1753 skip_space -= used_space;
1754 }
1755
1756 /*
1757 * we can use the free space in [0, skip_space - 1], subtract
1758 * it from the total.
1759 */
1760 if (avail_space && avail_space >= skip_space)
1761 avail_space -= skip_space;
1762 else
1763 avail_space = 0;
1764
1765 if (avail_space < min_stripe_size)
1766 continue;
1767
1768 devices_info[i].dev = device;
1769 devices_info[i].max_avail = avail_space;
1770
1771 i++;
1772 }
1773 rcu_read_unlock();
1774 if (fs_info->alloc_start)
1775 mutex_unlock(&fs_devices->device_list_mutex);
1776
1777 nr_devices = i;
1778
1779 btrfs_descending_sort_devices(devices_info, nr_devices);
1780
1781 i = nr_devices - 1;
1782 avail_space = 0;
1783 while (nr_devices >= min_stripes) {
1784 if (num_stripes > nr_devices)
1785 num_stripes = nr_devices;
1786
1787 if (devices_info[i].max_avail >= min_stripe_size) {
1788 int j;
1789 u64 alloc_size;
1790
1791 avail_space += devices_info[i].max_avail * num_stripes;
1792 alloc_size = devices_info[i].max_avail;
1793 for (j = i + 1 - num_stripes; j <= i; j++)
1794 devices_info[j].max_avail -= alloc_size;
1795 }
1796 i--;
1797 nr_devices--;
1798 }
1799
1800 kfree(devices_info);
1801 *free_bytes = avail_space;
1802 return 0;
1803 }
1804
1805 /*
1806 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles.
1807 *
1808 * If there's a redundant raid level at DATA block groups, use the respective
1809 * multiplier to scale the sizes.
1810 *
1811 * Unused device space usage is based on simulating the chunk allocator
1812 * algorithm that respects the device sizes, order of allocations and the
1813 * 'alloc_start' value, this is a close approximation of the actual use but
1814 * there are other factors that may change the result (like a new metadata
1815 * chunk).
1816 *
1817 * FIXME: not accurate for mixed block groups, total and free/used are ok,
1818 * available appears slightly larger.
1819 */
1820 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1821 {
1822 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1823 struct btrfs_super_block *disk_super = fs_info->super_copy;
1824 struct list_head *head = &fs_info->space_info;
1825 struct btrfs_space_info *found;
1826 u64 total_used = 0;
1827 u64 total_free_data = 0;
1828 int bits = dentry->d_sb->s_blocksize_bits;
1829 __be32 *fsid = (__be32 *)fs_info->fsid;
1830 unsigned factor = 1;
1831 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
1832 int ret;
1833
1834 /*
1835 * holding chunk_muext to avoid allocating new chunks, holding
1836 * device_list_mutex to avoid the device being removed
1837 */
1838 rcu_read_lock();
1839 list_for_each_entry_rcu(found, head, list) {
1840 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1841 int i;
1842
1843 total_free_data += found->disk_total - found->disk_used;
1844 total_free_data -=
1845 btrfs_account_ro_block_groups_free_space(found);
1846
1847 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1848 if (!list_empty(&found->block_groups[i])) {
1849 switch (i) {
1850 case BTRFS_RAID_DUP:
1851 case BTRFS_RAID_RAID1:
1852 case BTRFS_RAID_RAID10:
1853 factor = 2;
1854 }
1855 }
1856 }
1857 }
1858
1859 total_used += found->disk_used;
1860 }
1861
1862 rcu_read_unlock();
1863
1864 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor);
1865 buf->f_blocks >>= bits;
1866 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits);
1867
1868 /* Account global block reserve as used, it's in logical size already */
1869 spin_lock(&block_rsv->lock);
1870 buf->f_bfree -= block_rsv->size >> bits;
1871 spin_unlock(&block_rsv->lock);
1872
1873 buf->f_bavail = div_u64(total_free_data, factor);
1874 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1875 if (ret)
1876 return ret;
1877 buf->f_bavail += div_u64(total_free_data, factor);
1878 buf->f_bavail = buf->f_bavail >> bits;
1879
1880 buf->f_type = BTRFS_SUPER_MAGIC;
1881 buf->f_bsize = dentry->d_sb->s_blocksize;
1882 buf->f_namelen = BTRFS_NAME_LEN;
1883
1884 /* We treat it as constant endianness (it doesn't matter _which_)
1885 because we want the fsid to come out the same whether mounted
1886 on a big-endian or little-endian host */
1887 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1888 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1889 /* Mask in the root object ID too, to disambiguate subvols */
1890 buf->f_fsid.val[0] ^= BTRFS_I(d_inode(dentry))->root->objectid >> 32;
1891 buf->f_fsid.val[1] ^= BTRFS_I(d_inode(dentry))->root->objectid;
1892
1893 return 0;
1894 }
1895
1896 static void btrfs_kill_super(struct super_block *sb)
1897 {
1898 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1899 kill_anon_super(sb);
1900 free_fs_info(fs_info);
1901 }
1902
1903 static struct file_system_type btrfs_fs_type = {
1904 .owner = THIS_MODULE,
1905 .name = "btrfs",
1906 .mount = btrfs_mount,
1907 .kill_sb = btrfs_kill_super,
1908 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
1909 };
1910 MODULE_ALIAS_FS("btrfs");
1911
1912 static int btrfs_control_open(struct inode *inode, struct file *file)
1913 {
1914 /*
1915 * The control file's private_data is used to hold the
1916 * transaction when it is started and is used to keep
1917 * track of whether a transaction is already in progress.
1918 */
1919 file->private_data = NULL;
1920 return 0;
1921 }
1922
1923 /*
1924 * used by btrfsctl to scan devices when no FS is mounted
1925 */
1926 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1927 unsigned long arg)
1928 {
1929 struct btrfs_ioctl_vol_args *vol;
1930 struct btrfs_fs_devices *fs_devices;
1931 int ret = -ENOTTY;
1932
1933 if (!capable(CAP_SYS_ADMIN))
1934 return -EPERM;
1935
1936 vol = memdup_user((void __user *)arg, sizeof(*vol));
1937 if (IS_ERR(vol))
1938 return PTR_ERR(vol);
1939
1940 switch (cmd) {
1941 case BTRFS_IOC_SCAN_DEV:
1942 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1943 &btrfs_fs_type, &fs_devices);
1944 break;
1945 case BTRFS_IOC_DEVICES_READY:
1946 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1947 &btrfs_fs_type, &fs_devices);
1948 if (ret)
1949 break;
1950 ret = !(fs_devices->num_devices == fs_devices->total_devices);
1951 break;
1952 }
1953
1954 kfree(vol);
1955 return ret;
1956 }
1957
1958 static int btrfs_freeze(struct super_block *sb)
1959 {
1960 struct btrfs_trans_handle *trans;
1961 struct btrfs_root *root = btrfs_sb(sb)->tree_root;
1962
1963 trans = btrfs_attach_transaction_barrier(root);
1964 if (IS_ERR(trans)) {
1965 /* no transaction, don't bother */
1966 if (PTR_ERR(trans) == -ENOENT)
1967 return 0;
1968 return PTR_ERR(trans);
1969 }
1970 return btrfs_commit_transaction(trans, root);
1971 }
1972
1973 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1974 {
1975 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1976 struct btrfs_fs_devices *cur_devices;
1977 struct btrfs_device *dev, *first_dev = NULL;
1978 struct list_head *head;
1979 struct rcu_string *name;
1980
1981 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1982 cur_devices = fs_info->fs_devices;
1983 while (cur_devices) {
1984 head = &cur_devices->devices;
1985 list_for_each_entry(dev, head, dev_list) {
1986 if (dev->missing)
1987 continue;
1988 if (!dev->name)
1989 continue;
1990 if (!first_dev || dev->devid < first_dev->devid)
1991 first_dev = dev;
1992 }
1993 cur_devices = cur_devices->seed;
1994 }
1995
1996 if (first_dev) {
1997 rcu_read_lock();
1998 name = rcu_dereference(first_dev->name);
1999 seq_escape(m, name->str, " \t\n\\");
2000 rcu_read_unlock();
2001 } else {
2002 WARN_ON(1);
2003 }
2004 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2005 return 0;
2006 }
2007
2008 static const struct super_operations btrfs_super_ops = {
2009 .drop_inode = btrfs_drop_inode,
2010 .evict_inode = btrfs_evict_inode,
2011 .put_super = btrfs_put_super,
2012 .sync_fs = btrfs_sync_fs,
2013 .show_options = btrfs_show_options,
2014 .show_devname = btrfs_show_devname,
2015 .write_inode = btrfs_write_inode,
2016 .alloc_inode = btrfs_alloc_inode,
2017 .destroy_inode = btrfs_destroy_inode,
2018 .statfs = btrfs_statfs,
2019 .remount_fs = btrfs_remount,
2020 .freeze_fs = btrfs_freeze,
2021 };
2022
2023 static const struct file_operations btrfs_ctl_fops = {
2024 .open = btrfs_control_open,
2025 .unlocked_ioctl = btrfs_control_ioctl,
2026 .compat_ioctl = btrfs_control_ioctl,
2027 .owner = THIS_MODULE,
2028 .llseek = noop_llseek,
2029 };
2030
2031 static struct miscdevice btrfs_misc = {
2032 .minor = BTRFS_MINOR,
2033 .name = "btrfs-control",
2034 .fops = &btrfs_ctl_fops
2035 };
2036
2037 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
2038 MODULE_ALIAS("devname:btrfs-control");
2039
2040 static int btrfs_interface_init(void)
2041 {
2042 return misc_register(&btrfs_misc);
2043 }
2044
2045 static void btrfs_interface_exit(void)
2046 {
2047 if (misc_deregister(&btrfs_misc) < 0)
2048 printk(KERN_INFO "BTRFS: misc_deregister failed for control device\n");
2049 }
2050
2051 static void btrfs_print_info(void)
2052 {
2053 printk(KERN_INFO "Btrfs loaded"
2054 #ifdef CONFIG_BTRFS_DEBUG
2055 ", debug=on"
2056 #endif
2057 #ifdef CONFIG_BTRFS_ASSERT
2058 ", assert=on"
2059 #endif
2060 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2061 ", integrity-checker=on"
2062 #endif
2063 "\n");
2064 }
2065
2066 static int btrfs_run_sanity_tests(void)
2067 {
2068 int ret;
2069
2070 ret = btrfs_init_test_fs();
2071 if (ret)
2072 return ret;
2073
2074 ret = btrfs_test_free_space_cache();
2075 if (ret)
2076 goto out;
2077 ret = btrfs_test_extent_buffer_operations();
2078 if (ret)
2079 goto out;
2080 ret = btrfs_test_extent_io();
2081 if (ret)
2082 goto out;
2083 ret = btrfs_test_inodes();
2084 if (ret)
2085 goto out;
2086 ret = btrfs_test_qgroups();
2087 out:
2088 btrfs_destroy_test_fs();
2089 return ret;
2090 }
2091
2092 static int __init init_btrfs_fs(void)
2093 {
2094 int err;
2095
2096 err = btrfs_hash_init();
2097 if (err)
2098 return err;
2099
2100 btrfs_props_init();
2101
2102 err = btrfs_init_sysfs();
2103 if (err)
2104 goto free_hash;
2105
2106 btrfs_init_compress();
2107
2108 err = btrfs_init_cachep();
2109 if (err)
2110 goto free_compress;
2111
2112 err = extent_io_init();
2113 if (err)
2114 goto free_cachep;
2115
2116 err = extent_map_init();
2117 if (err)
2118 goto free_extent_io;
2119
2120 err = ordered_data_init();
2121 if (err)
2122 goto free_extent_map;
2123
2124 err = btrfs_delayed_inode_init();
2125 if (err)
2126 goto free_ordered_data;
2127
2128 err = btrfs_auto_defrag_init();
2129 if (err)
2130 goto free_delayed_inode;
2131
2132 err = btrfs_delayed_ref_init();
2133 if (err)
2134 goto free_auto_defrag;
2135
2136 err = btrfs_prelim_ref_init();
2137 if (err)
2138 goto free_delayed_ref;
2139
2140 err = btrfs_end_io_wq_init();
2141 if (err)
2142 goto free_prelim_ref;
2143
2144 err = btrfs_interface_init();
2145 if (err)
2146 goto free_end_io_wq;
2147
2148 btrfs_init_lockdep();
2149
2150 btrfs_print_info();
2151
2152 err = btrfs_run_sanity_tests();
2153 if (err)
2154 goto unregister_ioctl;
2155
2156 err = register_filesystem(&btrfs_fs_type);
2157 if (err)
2158 goto unregister_ioctl;
2159
2160 return 0;
2161
2162 unregister_ioctl:
2163 btrfs_interface_exit();
2164 free_end_io_wq:
2165 btrfs_end_io_wq_exit();
2166 free_prelim_ref:
2167 btrfs_prelim_ref_exit();
2168 free_delayed_ref:
2169 btrfs_delayed_ref_exit();
2170 free_auto_defrag:
2171 btrfs_auto_defrag_exit();
2172 free_delayed_inode:
2173 btrfs_delayed_inode_exit();
2174 free_ordered_data:
2175 ordered_data_exit();
2176 free_extent_map:
2177 extent_map_exit();
2178 free_extent_io:
2179 extent_io_exit();
2180 free_cachep:
2181 btrfs_destroy_cachep();
2182 free_compress:
2183 btrfs_exit_compress();
2184 btrfs_exit_sysfs();
2185 free_hash:
2186 btrfs_hash_exit();
2187 return err;
2188 }
2189
2190 static void __exit exit_btrfs_fs(void)
2191 {
2192 btrfs_destroy_cachep();
2193 btrfs_delayed_ref_exit();
2194 btrfs_auto_defrag_exit();
2195 btrfs_delayed_inode_exit();
2196 btrfs_prelim_ref_exit();
2197 ordered_data_exit();
2198 extent_map_exit();
2199 extent_io_exit();
2200 btrfs_interface_exit();
2201 btrfs_end_io_wq_exit();
2202 unregister_filesystem(&btrfs_fs_type);
2203 btrfs_exit_sysfs();
2204 btrfs_cleanup_fs_uuids();
2205 btrfs_exit_compress();
2206 btrfs_hash_exit();
2207 }
2208
2209 late_initcall(init_btrfs_fs);
2210 module_exit(exit_btrfs_fs)
2211
2212 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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