1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2007 Oracle. All rights reserved.
6 #include <linux/blkdev.h>
7 #include <linux/module.h>
9 #include <linux/pagemap.h>
10 #include <linux/highmem.h>
11 #include <linux/time.h>
12 #include <linux/init.h>
13 #include <linux/seq_file.h>
14 #include <linux/string.h>
15 #include <linux/backing-dev.h>
16 #include <linux/mount.h>
17 #include <linux/writeback.h>
18 #include <linux/statfs.h>
19 #include <linux/compat.h>
20 #include <linux/parser.h>
21 #include <linux/ctype.h>
22 #include <linux/namei.h>
23 #include <linux/miscdevice.h>
24 #include <linux/magic.h>
25 #include <linux/slab.h>
26 #include <linux/cleancache.h>
27 #include <linux/ratelimit.h>
28 #include <linux/crc32c.h>
29 #include <linux/btrfs.h>
30 #include "delayed-inode.h"
33 #include "transaction.h"
34 #include "btrfs_inode.h"
35 #include "print-tree.h"
40 #include "compression.h"
41 #include "rcu-string.h"
42 #include "dev-replace.h"
43 #include "free-space-cache.h"
45 #include "space-info.h"
48 #include "tests/btrfs-tests.h"
49 #include "block-group.h"
52 #define CREATE_TRACE_POINTS
53 #include <trace/events/btrfs.h>
55 static const struct super_operations btrfs_super_ops;
58 * Types for mounting the default subvolume and a subvolume explicitly
59 * requested by subvol=/path. That way the callchain is straightforward and we
60 * don't have to play tricks with the mount options and recursive calls to
63 * The new btrfs_root_fs_type also servers as a tag for the bdev_holder.
65 static struct file_system_type btrfs_fs_type;
66 static struct file_system_type btrfs_root_fs_type;
68 static int btrfs_remount(struct super_block *sb, int *flags, char *data);
71 * Generally the error codes correspond to their respective errors, but there
72 * are a few special cases.
74 * EUCLEAN: Any sort of corruption that we encounter. The tree-checker for
75 * instance will return EUCLEAN if any of the blocks are corrupted in
76 * a way that is problematic. We want to reserve EUCLEAN for these
77 * sort of corruptions.
79 * EROFS: If we check BTRFS_FS_STATE_ERROR and fail out with a return error, we
80 * need to use EROFS for this case. We will have no idea of the
81 * original failure, that will have been reported at the time we tripped
82 * over the error. Each subsequent error that doesn't have any context
83 * of the original error should use EROFS when handling BTRFS_FS_STATE_ERROR.
85 const char * __attribute_const__ btrfs_decode_error(int errno)
87 char *errstr = "unknown";
90 case -ENOENT: /* -2 */
91 errstr = "No such entry";
94 errstr = "IO failure";
96 case -ENOMEM: /* -12*/
97 errstr = "Out of memory";
99 case -EEXIST: /* -17 */
100 errstr = "Object already exists";
102 case -ENOSPC: /* -28 */
103 errstr = "No space left";
105 case -EROFS: /* -30 */
106 errstr = "Readonly filesystem";
108 case -EOPNOTSUPP: /* -95 */
109 errstr = "Operation not supported";
111 case -EUCLEAN: /* -117 */
112 errstr = "Filesystem corrupted";
114 case -EDQUOT: /* -122 */
115 errstr = "Quota exceeded";
123 * __btrfs_handle_fs_error decodes expected errors from the caller and
124 * invokes the appropriate error response.
127 void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function,
128 unsigned int line, int errno, const char *fmt, ...)
130 struct super_block *sb = fs_info->sb;
136 * Special case: if the error is EROFS, and we're already
137 * under SB_RDONLY, then it is safe here.
139 if (errno == -EROFS && sb_rdonly(sb))
143 errstr = btrfs_decode_error(errno);
145 struct va_format vaf;
152 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
153 sb->s_id, function, line, errno, errstr, &vaf);
156 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
157 sb->s_id, function, line, errno, errstr);
162 * Today we only save the error info to memory. Long term we'll
163 * also send it down to the disk
165 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
167 /* Don't go through full error handling during mount */
168 if (!(sb->s_flags & SB_BORN))
174 btrfs_discard_stop(fs_info);
176 /* btrfs handle error by forcing the filesystem readonly */
177 btrfs_set_sb_rdonly(sb);
178 btrfs_info(fs_info, "forced readonly");
180 * Note that a running device replace operation is not canceled here
181 * although there is no way to update the progress. It would add the
182 * risk of a deadlock, therefore the canceling is omitted. The only
183 * penalty is that some I/O remains active until the procedure
184 * completes. The next time when the filesystem is mounted writable
185 * again, the device replace operation continues.
190 static const char * const logtypes[] = {
203 * Use one ratelimit state per log level so that a flood of less important
204 * messages doesn't cause more important ones to be dropped.
206 static struct ratelimit_state printk_limits[] = {
207 RATELIMIT_STATE_INIT(printk_limits[0], DEFAULT_RATELIMIT_INTERVAL, 100),
208 RATELIMIT_STATE_INIT(printk_limits[1], DEFAULT_RATELIMIT_INTERVAL, 100),
209 RATELIMIT_STATE_INIT(printk_limits[2], DEFAULT_RATELIMIT_INTERVAL, 100),
210 RATELIMIT_STATE_INIT(printk_limits[3], DEFAULT_RATELIMIT_INTERVAL, 100),
211 RATELIMIT_STATE_INIT(printk_limits[4], DEFAULT_RATELIMIT_INTERVAL, 100),
212 RATELIMIT_STATE_INIT(printk_limits[5], DEFAULT_RATELIMIT_INTERVAL, 100),
213 RATELIMIT_STATE_INIT(printk_limits[6], DEFAULT_RATELIMIT_INTERVAL, 100),
214 RATELIMIT_STATE_INIT(printk_limits[7], DEFAULT_RATELIMIT_INTERVAL, 100),
217 void __cold btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
219 char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1] = "\0";
220 struct va_format vaf;
223 const char *type = logtypes[4];
224 struct ratelimit_state *ratelimit = &printk_limits[4];
228 while ((kern_level = printk_get_level(fmt)) != 0) {
229 size_t size = printk_skip_level(fmt) - fmt;
231 if (kern_level >= '0' && kern_level <= '7') {
232 memcpy(lvl, fmt, size);
234 type = logtypes[kern_level - '0'];
235 ratelimit = &printk_limits[kern_level - '0'];
243 if (__ratelimit(ratelimit)) {
245 printk("%sBTRFS %s (device %s): %pV\n", lvl, type,
246 fs_info->sb->s_id, &vaf);
248 printk("%sBTRFS %s: %pV\n", lvl, type, &vaf);
256 * We only mark the transaction aborted and then set the file system read-only.
257 * This will prevent new transactions from starting or trying to join this
260 * This means that error recovery at the call site is limited to freeing
261 * any local memory allocations and passing the error code up without
262 * further cleanup. The transaction should complete as it normally would
263 * in the call path but will return -EIO.
265 * We'll complete the cleanup in btrfs_end_transaction and
266 * btrfs_commit_transaction.
269 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
270 const char *function,
271 unsigned int line, int errno)
273 struct btrfs_fs_info *fs_info = trans->fs_info;
275 WRITE_ONCE(trans->aborted, errno);
276 /* Nothing used. The other threads that have joined this
277 * transaction may be able to continue. */
278 if (!trans->dirty && list_empty(&trans->new_bgs)) {
281 errstr = btrfs_decode_error(errno);
283 "%s:%d: Aborting unused transaction(%s).",
284 function, line, errstr);
287 WRITE_ONCE(trans->transaction->aborted, errno);
288 /* Wake up anybody who may be waiting on this transaction */
289 wake_up(&fs_info->transaction_wait);
290 wake_up(&fs_info->transaction_blocked_wait);
291 __btrfs_handle_fs_error(fs_info, function, line, errno, NULL);
294 * __btrfs_panic decodes unexpected, fatal errors from the caller,
295 * issues an alert, and either panics or BUGs, depending on mount options.
298 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
299 unsigned int line, int errno, const char *fmt, ...)
301 char *s_id = "<unknown>";
303 struct va_format vaf = { .fmt = fmt };
307 s_id = fs_info->sb->s_id;
312 errstr = btrfs_decode_error(errno);
313 if (fs_info && (btrfs_test_opt(fs_info, PANIC_ON_FATAL_ERROR)))
314 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
315 s_id, function, line, &vaf, errno, errstr);
317 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
318 function, line, &vaf, errno, errstr);
320 /* Caller calls BUG() */
323 static void btrfs_put_super(struct super_block *sb)
325 close_ctree(btrfs_sb(sb));
334 Opt_compress_force_type,
339 Opt_flushoncommit, Opt_noflushoncommit,
341 Opt_barrier, Opt_nobarrier,
342 Opt_datacow, Opt_nodatacow,
343 Opt_datasum, Opt_nodatasum,
344 Opt_defrag, Opt_nodefrag,
345 Opt_discard, Opt_nodiscard,
349 Opt_rescan_uuid_tree,
351 Opt_space_cache, Opt_no_space_cache,
352 Opt_space_cache_version,
354 Opt_ssd_spread, Opt_nossd_spread,
359 Opt_treelog, Opt_notreelog,
360 Opt_user_subvol_rm_allowed,
370 /* Deprecated options */
372 Opt_inode_cache, Opt_noinode_cache,
374 /* Debugging options */
376 Opt_check_integrity_including_extent_data,
377 Opt_check_integrity_print_mask,
378 Opt_enospc_debug, Opt_noenospc_debug,
379 #ifdef CONFIG_BTRFS_DEBUG
380 Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all,
382 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
388 static const match_table_t tokens = {
390 {Opt_noacl, "noacl"},
391 {Opt_clear_cache, "clear_cache"},
392 {Opt_commit_interval, "commit=%u"},
393 {Opt_compress, "compress"},
394 {Opt_compress_type, "compress=%s"},
395 {Opt_compress_force, "compress-force"},
396 {Opt_compress_force_type, "compress-force=%s"},
397 {Opt_degraded, "degraded"},
398 {Opt_device, "device=%s"},
399 {Opt_fatal_errors, "fatal_errors=%s"},
400 {Opt_flushoncommit, "flushoncommit"},
401 {Opt_noflushoncommit, "noflushoncommit"},
402 {Opt_inode_cache, "inode_cache"},
403 {Opt_noinode_cache, "noinode_cache"},
404 {Opt_max_inline, "max_inline=%s"},
405 {Opt_barrier, "barrier"},
406 {Opt_nobarrier, "nobarrier"},
407 {Opt_datacow, "datacow"},
408 {Opt_nodatacow, "nodatacow"},
409 {Opt_datasum, "datasum"},
410 {Opt_nodatasum, "nodatasum"},
411 {Opt_defrag, "autodefrag"},
412 {Opt_nodefrag, "noautodefrag"},
413 {Opt_discard, "discard"},
414 {Opt_discard_mode, "discard=%s"},
415 {Opt_nodiscard, "nodiscard"},
416 {Opt_norecovery, "norecovery"},
417 {Opt_ratio, "metadata_ratio=%u"},
418 {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
419 {Opt_skip_balance, "skip_balance"},
420 {Opt_space_cache, "space_cache"},
421 {Opt_no_space_cache, "nospace_cache"},
422 {Opt_space_cache_version, "space_cache=%s"},
424 {Opt_nossd, "nossd"},
425 {Opt_ssd_spread, "ssd_spread"},
426 {Opt_nossd_spread, "nossd_spread"},
427 {Opt_subvol, "subvol=%s"},
428 {Opt_subvol_empty, "subvol="},
429 {Opt_subvolid, "subvolid=%s"},
430 {Opt_thread_pool, "thread_pool=%u"},
431 {Opt_treelog, "treelog"},
432 {Opt_notreelog, "notreelog"},
433 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
436 {Opt_rescue, "rescue=%s"},
437 /* Deprecated, with alias rescue=nologreplay */
438 {Opt_nologreplay, "nologreplay"},
439 /* Deprecated, with alias rescue=usebackuproot */
440 {Opt_usebackuproot, "usebackuproot"},
442 /* Deprecated options */
443 {Opt_recovery, "recovery"},
445 /* Debugging options */
446 {Opt_check_integrity, "check_int"},
447 {Opt_check_integrity_including_extent_data, "check_int_data"},
448 {Opt_check_integrity_print_mask, "check_int_print_mask=%u"},
449 {Opt_enospc_debug, "enospc_debug"},
450 {Opt_noenospc_debug, "noenospc_debug"},
451 #ifdef CONFIG_BTRFS_DEBUG
452 {Opt_fragment_data, "fragment=data"},
453 {Opt_fragment_metadata, "fragment=metadata"},
454 {Opt_fragment_all, "fragment=all"},
456 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
457 {Opt_ref_verify, "ref_verify"},
462 static const match_table_t rescue_tokens = {
463 {Opt_usebackuproot, "usebackuproot"},
464 {Opt_nologreplay, "nologreplay"},
465 {Opt_ignorebadroots, "ignorebadroots"},
466 {Opt_ignorebadroots, "ibadroots"},
467 {Opt_ignoredatacsums, "ignoredatacsums"},
468 {Opt_ignoredatacsums, "idatacsums"},
469 {Opt_rescue_all, "all"},
473 static bool check_ro_option(struct btrfs_fs_info *fs_info, unsigned long opt,
474 const char *opt_name)
476 if (fs_info->mount_opt & opt) {
477 btrfs_err(fs_info, "%s must be used with ro mount option",
484 static int parse_rescue_options(struct btrfs_fs_info *info, const char *options)
489 substring_t args[MAX_OPT_ARGS];
492 opts = kstrdup(options, GFP_KERNEL);
497 while ((p = strsep(&opts, ":")) != NULL) {
502 token = match_token(p, rescue_tokens, args);
504 case Opt_usebackuproot:
506 "trying to use backup root at mount time");
507 btrfs_set_opt(info->mount_opt, USEBACKUPROOT);
509 case Opt_nologreplay:
510 btrfs_set_and_info(info, NOLOGREPLAY,
511 "disabling log replay at mount time");
513 case Opt_ignorebadroots:
514 btrfs_set_and_info(info, IGNOREBADROOTS,
515 "ignoring bad roots");
517 case Opt_ignoredatacsums:
518 btrfs_set_and_info(info, IGNOREDATACSUMS,
519 "ignoring data csums");
522 btrfs_info(info, "enabling all of the rescue options");
523 btrfs_set_and_info(info, IGNOREDATACSUMS,
524 "ignoring data csums");
525 btrfs_set_and_info(info, IGNOREBADROOTS,
526 "ignoring bad roots");
527 btrfs_set_and_info(info, NOLOGREPLAY,
528 "disabling log replay at mount time");
531 btrfs_info(info, "unrecognized rescue option '%s'", p);
545 * Regular mount options parser. Everything that is needed only when
546 * reading in a new superblock is parsed here.
547 * XXX JDM: This needs to be cleaned up for remount.
549 int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
550 unsigned long new_flags)
552 substring_t args[MAX_OPT_ARGS];
557 bool compress_force = false;
558 enum btrfs_compression_type saved_compress_type;
559 int saved_compress_level;
560 bool saved_compress_force;
563 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
564 btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
565 else if (btrfs_free_space_cache_v1_active(info)) {
566 if (btrfs_is_zoned(info)) {
568 "zoned: clearing existing space cache");
569 btrfs_set_super_cache_generation(info->super_copy, 0);
571 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
576 * Even the options are empty, we still need to do extra check
582 while ((p = strsep(&options, ",")) != NULL) {
587 token = match_token(p, tokens, args);
590 btrfs_info(info, "allowing degraded mounts");
591 btrfs_set_opt(info->mount_opt, DEGRADED);
594 case Opt_subvol_empty:
598 * These are parsed by btrfs_parse_subvol_options or
599 * btrfs_parse_device_options and can be ignored here.
603 btrfs_set_and_info(info, NODATASUM,
604 "setting nodatasum");
607 if (btrfs_test_opt(info, NODATASUM)) {
608 if (btrfs_test_opt(info, NODATACOW))
610 "setting datasum, datacow enabled");
612 btrfs_info(info, "setting datasum");
614 btrfs_clear_opt(info->mount_opt, NODATACOW);
615 btrfs_clear_opt(info->mount_opt, NODATASUM);
618 if (!btrfs_test_opt(info, NODATACOW)) {
619 if (!btrfs_test_opt(info, COMPRESS) ||
620 !btrfs_test_opt(info, FORCE_COMPRESS)) {
622 "setting nodatacow, compression disabled");
624 btrfs_info(info, "setting nodatacow");
627 btrfs_clear_opt(info->mount_opt, COMPRESS);
628 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
629 btrfs_set_opt(info->mount_opt, NODATACOW);
630 btrfs_set_opt(info->mount_opt, NODATASUM);
633 btrfs_clear_and_info(info, NODATACOW,
636 case Opt_compress_force:
637 case Opt_compress_force_type:
638 compress_force = true;
641 case Opt_compress_type:
642 saved_compress_type = btrfs_test_opt(info,
644 info->compress_type : BTRFS_COMPRESS_NONE;
645 saved_compress_force =
646 btrfs_test_opt(info, FORCE_COMPRESS);
647 saved_compress_level = info->compress_level;
648 if (token == Opt_compress ||
649 token == Opt_compress_force ||
650 strncmp(args[0].from, "zlib", 4) == 0) {
651 compress_type = "zlib";
653 info->compress_type = BTRFS_COMPRESS_ZLIB;
654 info->compress_level = BTRFS_ZLIB_DEFAULT_LEVEL;
656 * args[0] contains uninitialized data since
657 * for these tokens we don't expect any
660 if (token != Opt_compress &&
661 token != Opt_compress_force)
662 info->compress_level =
663 btrfs_compress_str2level(
666 btrfs_set_opt(info->mount_opt, COMPRESS);
667 btrfs_clear_opt(info->mount_opt, NODATACOW);
668 btrfs_clear_opt(info->mount_opt, NODATASUM);
670 } else if (strncmp(args[0].from, "lzo", 3) == 0) {
671 compress_type = "lzo";
672 info->compress_type = BTRFS_COMPRESS_LZO;
673 info->compress_level = 0;
674 btrfs_set_opt(info->mount_opt, COMPRESS);
675 btrfs_clear_opt(info->mount_opt, NODATACOW);
676 btrfs_clear_opt(info->mount_opt, NODATASUM);
677 btrfs_set_fs_incompat(info, COMPRESS_LZO);
679 } else if (strncmp(args[0].from, "zstd", 4) == 0) {
680 compress_type = "zstd";
681 info->compress_type = BTRFS_COMPRESS_ZSTD;
682 info->compress_level =
683 btrfs_compress_str2level(
686 btrfs_set_opt(info->mount_opt, COMPRESS);
687 btrfs_clear_opt(info->mount_opt, NODATACOW);
688 btrfs_clear_opt(info->mount_opt, NODATASUM);
689 btrfs_set_fs_incompat(info, COMPRESS_ZSTD);
691 } else if (strncmp(args[0].from, "no", 2) == 0) {
692 compress_type = "no";
693 info->compress_level = 0;
694 info->compress_type = 0;
695 btrfs_clear_opt(info->mount_opt, COMPRESS);
696 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
697 compress_force = false;
704 if (compress_force) {
705 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
708 * If we remount from compress-force=xxx to
709 * compress=xxx, we need clear FORCE_COMPRESS
710 * flag, otherwise, there is no way for users
711 * to disable forcible compression separately.
713 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
715 if (no_compress == 1) {
716 btrfs_info(info, "use no compression");
717 } else if ((info->compress_type != saved_compress_type) ||
718 (compress_force != saved_compress_force) ||
719 (info->compress_level != saved_compress_level)) {
720 btrfs_info(info, "%s %s compression, level %d",
721 (compress_force) ? "force" : "use",
722 compress_type, info->compress_level);
724 compress_force = false;
727 btrfs_set_and_info(info, SSD,
728 "enabling ssd optimizations");
729 btrfs_clear_opt(info->mount_opt, NOSSD);
732 btrfs_set_and_info(info, SSD,
733 "enabling ssd optimizations");
734 btrfs_set_and_info(info, SSD_SPREAD,
735 "using spread ssd allocation scheme");
736 btrfs_clear_opt(info->mount_opt, NOSSD);
739 btrfs_set_opt(info->mount_opt, NOSSD);
740 btrfs_clear_and_info(info, SSD,
741 "not using ssd optimizations");
743 case Opt_nossd_spread:
744 btrfs_clear_and_info(info, SSD_SPREAD,
745 "not using spread ssd allocation scheme");
748 btrfs_clear_and_info(info, NOBARRIER,
749 "turning on barriers");
752 btrfs_set_and_info(info, NOBARRIER,
753 "turning off barriers");
755 case Opt_thread_pool:
756 ret = match_int(&args[0], &intarg);
759 } else if (intarg == 0) {
763 info->thread_pool_size = intarg;
766 num = match_strdup(&args[0]);
768 info->max_inline = memparse(num, NULL);
771 if (info->max_inline) {
772 info->max_inline = min_t(u64,
776 btrfs_info(info, "max_inline at %llu",
784 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
785 info->sb->s_flags |= SB_POSIXACL;
788 btrfs_err(info, "support for ACL not compiled in!");
793 info->sb->s_flags &= ~SB_POSIXACL;
796 btrfs_set_and_info(info, NOTREELOG,
797 "disabling tree log");
800 btrfs_clear_and_info(info, NOTREELOG,
801 "enabling tree log");
804 case Opt_nologreplay:
806 "'nologreplay' is deprecated, use 'rescue=nologreplay' instead");
807 btrfs_set_and_info(info, NOLOGREPLAY,
808 "disabling log replay at mount time");
810 case Opt_flushoncommit:
811 btrfs_set_and_info(info, FLUSHONCOMMIT,
812 "turning on flush-on-commit");
814 case Opt_noflushoncommit:
815 btrfs_clear_and_info(info, FLUSHONCOMMIT,
816 "turning off flush-on-commit");
819 ret = match_int(&args[0], &intarg);
822 info->metadata_ratio = intarg;
823 btrfs_info(info, "metadata ratio %u",
824 info->metadata_ratio);
827 case Opt_discard_mode:
828 if (token == Opt_discard ||
829 strcmp(args[0].from, "sync") == 0) {
830 btrfs_clear_opt(info->mount_opt, DISCARD_ASYNC);
831 btrfs_set_and_info(info, DISCARD_SYNC,
832 "turning on sync discard");
833 } else if (strcmp(args[0].from, "async") == 0) {
834 btrfs_clear_opt(info->mount_opt, DISCARD_SYNC);
835 btrfs_set_and_info(info, DISCARD_ASYNC,
836 "turning on async discard");
843 btrfs_clear_and_info(info, DISCARD_SYNC,
844 "turning off discard");
845 btrfs_clear_and_info(info, DISCARD_ASYNC,
846 "turning off async discard");
848 case Opt_space_cache:
849 case Opt_space_cache_version:
850 if (token == Opt_space_cache ||
851 strcmp(args[0].from, "v1") == 0) {
852 btrfs_clear_opt(info->mount_opt,
854 btrfs_set_and_info(info, SPACE_CACHE,
855 "enabling disk space caching");
856 } else if (strcmp(args[0].from, "v2") == 0) {
857 btrfs_clear_opt(info->mount_opt,
859 btrfs_set_and_info(info, FREE_SPACE_TREE,
860 "enabling free space tree");
866 case Opt_rescan_uuid_tree:
867 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
869 case Opt_no_space_cache:
870 if (btrfs_test_opt(info, SPACE_CACHE)) {
871 btrfs_clear_and_info(info, SPACE_CACHE,
872 "disabling disk space caching");
874 if (btrfs_test_opt(info, FREE_SPACE_TREE)) {
875 btrfs_clear_and_info(info, FREE_SPACE_TREE,
876 "disabling free space tree");
879 case Opt_inode_cache:
880 case Opt_noinode_cache:
882 "the 'inode_cache' option is deprecated and has no effect since 5.11");
884 case Opt_clear_cache:
885 btrfs_set_and_info(info, CLEAR_CACHE,
886 "force clearing of disk cache");
888 case Opt_user_subvol_rm_allowed:
889 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
891 case Opt_enospc_debug:
892 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
894 case Opt_noenospc_debug:
895 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
898 btrfs_set_and_info(info, AUTO_DEFRAG,
899 "enabling auto defrag");
902 btrfs_clear_and_info(info, AUTO_DEFRAG,
903 "disabling auto defrag");
906 case Opt_usebackuproot:
908 "'%s' is deprecated, use 'rescue=usebackuproot' instead",
909 token == Opt_recovery ? "recovery" :
912 "trying to use backup root at mount time");
913 btrfs_set_opt(info->mount_opt, USEBACKUPROOT);
915 case Opt_skip_balance:
916 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
918 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
919 case Opt_check_integrity_including_extent_data:
921 "enabling check integrity including extent data");
922 btrfs_set_opt(info->mount_opt,
923 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
924 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
926 case Opt_check_integrity:
927 btrfs_info(info, "enabling check integrity");
928 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
930 case Opt_check_integrity_print_mask:
931 ret = match_int(&args[0], &intarg);
934 info->check_integrity_print_mask = intarg;
935 btrfs_info(info, "check_integrity_print_mask 0x%x",
936 info->check_integrity_print_mask);
939 case Opt_check_integrity_including_extent_data:
940 case Opt_check_integrity:
941 case Opt_check_integrity_print_mask:
943 "support for check_integrity* not compiled in!");
947 case Opt_fatal_errors:
948 if (strcmp(args[0].from, "panic") == 0)
949 btrfs_set_opt(info->mount_opt,
950 PANIC_ON_FATAL_ERROR);
951 else if (strcmp(args[0].from, "bug") == 0)
952 btrfs_clear_opt(info->mount_opt,
953 PANIC_ON_FATAL_ERROR);
959 case Opt_commit_interval:
961 ret = match_int(&args[0], &intarg);
966 "using default commit interval %us",
967 BTRFS_DEFAULT_COMMIT_INTERVAL);
968 intarg = BTRFS_DEFAULT_COMMIT_INTERVAL;
969 } else if (intarg > 300) {
970 btrfs_warn(info, "excessive commit interval %d",
973 info->commit_interval = intarg;
976 ret = parse_rescue_options(info, args[0].from);
980 #ifdef CONFIG_BTRFS_DEBUG
981 case Opt_fragment_all:
982 btrfs_info(info, "fragmenting all space");
983 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
984 btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA);
986 case Opt_fragment_metadata:
987 btrfs_info(info, "fragmenting metadata");
988 btrfs_set_opt(info->mount_opt,
991 case Opt_fragment_data:
992 btrfs_info(info, "fragmenting data");
993 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
996 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
998 btrfs_info(info, "doing ref verification");
999 btrfs_set_opt(info->mount_opt, REF_VERIFY);
1003 btrfs_err(info, "unrecognized mount option '%s'", p);
1011 /* We're read-only, don't have to check. */
1012 if (new_flags & SB_RDONLY)
1015 if (check_ro_option(info, BTRFS_MOUNT_NOLOGREPLAY, "nologreplay") ||
1016 check_ro_option(info, BTRFS_MOUNT_IGNOREBADROOTS, "ignorebadroots") ||
1017 check_ro_option(info, BTRFS_MOUNT_IGNOREDATACSUMS, "ignoredatacsums"))
1020 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) &&
1021 !btrfs_test_opt(info, FREE_SPACE_TREE) &&
1022 !btrfs_test_opt(info, CLEAR_CACHE)) {
1023 btrfs_err(info, "cannot disable free space tree");
1028 ret = btrfs_check_mountopts_zoned(info);
1029 if (!ret && btrfs_test_opt(info, SPACE_CACHE))
1030 btrfs_info(info, "disk space caching is enabled");
1031 if (!ret && btrfs_test_opt(info, FREE_SPACE_TREE))
1032 btrfs_info(info, "using free space tree");
1037 * Parse mount options that are required early in the mount process.
1039 * All other options will be parsed on much later in the mount process and
1040 * only when we need to allocate a new super block.
1042 static int btrfs_parse_device_options(const char *options, fmode_t flags,
1045 substring_t args[MAX_OPT_ARGS];
1046 char *device_name, *opts, *orig, *p;
1047 struct btrfs_device *device = NULL;
1050 lockdep_assert_held(&uuid_mutex);
1056 * strsep changes the string, duplicate it because btrfs_parse_options
1059 opts = kstrdup(options, GFP_KERNEL);
1064 while ((p = strsep(&opts, ",")) != NULL) {
1070 token = match_token(p, tokens, args);
1071 if (token == Opt_device) {
1072 device_name = match_strdup(&args[0]);
1077 device = btrfs_scan_one_device(device_name, flags,
1080 if (IS_ERR(device)) {
1081 error = PTR_ERR(device);
1093 * Parse mount options that are related to subvolume id
1095 * The value is later passed to mount_subvol()
1097 static int btrfs_parse_subvol_options(const char *options, char **subvol_name,
1098 u64 *subvol_objectid)
1100 substring_t args[MAX_OPT_ARGS];
1101 char *opts, *orig, *p;
1109 * strsep changes the string, duplicate it because
1110 * btrfs_parse_device_options gets called later
1112 opts = kstrdup(options, GFP_KERNEL);
1117 while ((p = strsep(&opts, ",")) != NULL) {
1122 token = match_token(p, tokens, args);
1125 kfree(*subvol_name);
1126 *subvol_name = match_strdup(&args[0]);
1127 if (!*subvol_name) {
1133 error = match_u64(&args[0], &subvolid);
1137 /* we want the original fs_tree */
1139 subvolid = BTRFS_FS_TREE_OBJECTID;
1141 *subvol_objectid = subvolid;
1153 char *btrfs_get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
1154 u64 subvol_objectid)
1156 struct btrfs_root *root = fs_info->tree_root;
1157 struct btrfs_root *fs_root = NULL;
1158 struct btrfs_root_ref *root_ref;
1159 struct btrfs_inode_ref *inode_ref;
1160 struct btrfs_key key;
1161 struct btrfs_path *path = NULL;
1162 char *name = NULL, *ptr;
1167 path = btrfs_alloc_path();
1173 name = kmalloc(PATH_MAX, GFP_KERNEL);
1178 ptr = name + PATH_MAX - 1;
1182 * Walk up the subvolume trees in the tree of tree roots by root
1183 * backrefs until we hit the top-level subvolume.
1185 while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) {
1186 key.objectid = subvol_objectid;
1187 key.type = BTRFS_ROOT_BACKREF_KEY;
1188 key.offset = (u64)-1;
1190 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1193 } else if (ret > 0) {
1194 ret = btrfs_previous_item(root, path, subvol_objectid,
1195 BTRFS_ROOT_BACKREF_KEY);
1198 } else if (ret > 0) {
1204 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1205 subvol_objectid = key.offset;
1207 root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1208 struct btrfs_root_ref);
1209 len = btrfs_root_ref_name_len(path->nodes[0], root_ref);
1212 ret = -ENAMETOOLONG;
1215 read_extent_buffer(path->nodes[0], ptr + 1,
1216 (unsigned long)(root_ref + 1), len);
1218 dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref);
1219 btrfs_release_path(path);
1221 fs_root = btrfs_get_fs_root(fs_info, subvol_objectid, true);
1222 if (IS_ERR(fs_root)) {
1223 ret = PTR_ERR(fs_root);
1229 * Walk up the filesystem tree by inode refs until we hit the
1232 while (dirid != BTRFS_FIRST_FREE_OBJECTID) {
1233 key.objectid = dirid;
1234 key.type = BTRFS_INODE_REF_KEY;
1235 key.offset = (u64)-1;
1237 ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0);
1240 } else if (ret > 0) {
1241 ret = btrfs_previous_item(fs_root, path, dirid,
1242 BTRFS_INODE_REF_KEY);
1245 } else if (ret > 0) {
1251 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1254 inode_ref = btrfs_item_ptr(path->nodes[0],
1256 struct btrfs_inode_ref);
1257 len = btrfs_inode_ref_name_len(path->nodes[0],
1261 ret = -ENAMETOOLONG;
1264 read_extent_buffer(path->nodes[0], ptr + 1,
1265 (unsigned long)(inode_ref + 1), len);
1267 btrfs_release_path(path);
1269 btrfs_put_root(fs_root);
1273 btrfs_free_path(path);
1274 if (ptr == name + PATH_MAX - 1) {
1278 memmove(name, ptr, name + PATH_MAX - ptr);
1283 btrfs_put_root(fs_root);
1284 btrfs_free_path(path);
1286 return ERR_PTR(ret);
1289 static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid)
1291 struct btrfs_root *root = fs_info->tree_root;
1292 struct btrfs_dir_item *di;
1293 struct btrfs_path *path;
1294 struct btrfs_key location;
1297 path = btrfs_alloc_path();
1302 * Find the "default" dir item which points to the root item that we
1303 * will mount by default if we haven't been given a specific subvolume
1306 dir_id = btrfs_super_root_dir(fs_info->super_copy);
1307 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
1309 btrfs_free_path(path);
1314 * Ok the default dir item isn't there. This is weird since
1315 * it's always been there, but don't freak out, just try and
1316 * mount the top-level subvolume.
1318 btrfs_free_path(path);
1319 *objectid = BTRFS_FS_TREE_OBJECTID;
1323 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
1324 btrfs_free_path(path);
1325 *objectid = location.objectid;
1329 static int btrfs_fill_super(struct super_block *sb,
1330 struct btrfs_fs_devices *fs_devices,
1333 struct inode *inode;
1334 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1337 sb->s_maxbytes = MAX_LFS_FILESIZE;
1338 sb->s_magic = BTRFS_SUPER_MAGIC;
1339 sb->s_op = &btrfs_super_ops;
1340 sb->s_d_op = &btrfs_dentry_operations;
1341 sb->s_export_op = &btrfs_export_ops;
1342 sb->s_xattr = btrfs_xattr_handlers;
1343 sb->s_time_gran = 1;
1344 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
1345 sb->s_flags |= SB_POSIXACL;
1347 sb->s_flags |= SB_I_VERSION;
1348 sb->s_iflags |= SB_I_CGROUPWB;
1350 err = super_setup_bdi(sb);
1352 btrfs_err(fs_info, "super_setup_bdi failed");
1356 err = open_ctree(sb, fs_devices, (char *)data);
1358 btrfs_err(fs_info, "open_ctree failed");
1362 inode = btrfs_iget(sb, BTRFS_FIRST_FREE_OBJECTID, fs_info->fs_root);
1363 if (IS_ERR(inode)) {
1364 err = PTR_ERR(inode);
1368 sb->s_root = d_make_root(inode);
1374 cleancache_init_fs(sb);
1375 sb->s_flags |= SB_ACTIVE;
1379 close_ctree(fs_info);
1383 int btrfs_sync_fs(struct super_block *sb, int wait)
1385 struct btrfs_trans_handle *trans;
1386 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1387 struct btrfs_root *root = fs_info->tree_root;
1389 trace_btrfs_sync_fs(fs_info, wait);
1392 filemap_flush(fs_info->btree_inode->i_mapping);
1396 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
1398 trans = btrfs_attach_transaction_barrier(root);
1399 if (IS_ERR(trans)) {
1400 /* no transaction, don't bother */
1401 if (PTR_ERR(trans) == -ENOENT) {
1403 * Exit unless we have some pending changes
1404 * that need to go through commit
1406 if (fs_info->pending_changes == 0)
1409 * A non-blocking test if the fs is frozen. We must not
1410 * start a new transaction here otherwise a deadlock
1411 * happens. The pending operations are delayed to the
1412 * next commit after thawing.
1414 if (sb_start_write_trylock(sb))
1418 trans = btrfs_start_transaction(root, 0);
1421 return PTR_ERR(trans);
1423 return btrfs_commit_transaction(trans);
1426 static void print_rescue_option(struct seq_file *seq, const char *s, bool *printed)
1428 seq_printf(seq, "%s%s", (*printed) ? ":" : ",rescue=", s);
1432 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
1434 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
1435 const char *compress_type;
1436 const char *subvol_name;
1437 bool printed = false;
1439 if (btrfs_test_opt(info, DEGRADED))
1440 seq_puts(seq, ",degraded");
1441 if (btrfs_test_opt(info, NODATASUM))
1442 seq_puts(seq, ",nodatasum");
1443 if (btrfs_test_opt(info, NODATACOW))
1444 seq_puts(seq, ",nodatacow");
1445 if (btrfs_test_opt(info, NOBARRIER))
1446 seq_puts(seq, ",nobarrier");
1447 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE)
1448 seq_printf(seq, ",max_inline=%llu", info->max_inline);
1449 if (info->thread_pool_size != min_t(unsigned long,
1450 num_online_cpus() + 2, 8))
1451 seq_printf(seq, ",thread_pool=%u", info->thread_pool_size);
1452 if (btrfs_test_opt(info, COMPRESS)) {
1453 compress_type = btrfs_compress_type2str(info->compress_type);
1454 if (btrfs_test_opt(info, FORCE_COMPRESS))
1455 seq_printf(seq, ",compress-force=%s", compress_type);
1457 seq_printf(seq, ",compress=%s", compress_type);
1458 if (info->compress_level)
1459 seq_printf(seq, ":%d", info->compress_level);
1461 if (btrfs_test_opt(info, NOSSD))
1462 seq_puts(seq, ",nossd");
1463 if (btrfs_test_opt(info, SSD_SPREAD))
1464 seq_puts(seq, ",ssd_spread");
1465 else if (btrfs_test_opt(info, SSD))
1466 seq_puts(seq, ",ssd");
1467 if (btrfs_test_opt(info, NOTREELOG))
1468 seq_puts(seq, ",notreelog");
1469 if (btrfs_test_opt(info, NOLOGREPLAY))
1470 print_rescue_option(seq, "nologreplay", &printed);
1471 if (btrfs_test_opt(info, USEBACKUPROOT))
1472 print_rescue_option(seq, "usebackuproot", &printed);
1473 if (btrfs_test_opt(info, IGNOREBADROOTS))
1474 print_rescue_option(seq, "ignorebadroots", &printed);
1475 if (btrfs_test_opt(info, IGNOREDATACSUMS))
1476 print_rescue_option(seq, "ignoredatacsums", &printed);
1477 if (btrfs_test_opt(info, FLUSHONCOMMIT))
1478 seq_puts(seq, ",flushoncommit");
1479 if (btrfs_test_opt(info, DISCARD_SYNC))
1480 seq_puts(seq, ",discard");
1481 if (btrfs_test_opt(info, DISCARD_ASYNC))
1482 seq_puts(seq, ",discard=async");
1483 if (!(info->sb->s_flags & SB_POSIXACL))
1484 seq_puts(seq, ",noacl");
1485 if (btrfs_free_space_cache_v1_active(info))
1486 seq_puts(seq, ",space_cache");
1487 else if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
1488 seq_puts(seq, ",space_cache=v2");
1490 seq_puts(seq, ",nospace_cache");
1491 if (btrfs_test_opt(info, RESCAN_UUID_TREE))
1492 seq_puts(seq, ",rescan_uuid_tree");
1493 if (btrfs_test_opt(info, CLEAR_CACHE))
1494 seq_puts(seq, ",clear_cache");
1495 if (btrfs_test_opt(info, USER_SUBVOL_RM_ALLOWED))
1496 seq_puts(seq, ",user_subvol_rm_allowed");
1497 if (btrfs_test_opt(info, ENOSPC_DEBUG))
1498 seq_puts(seq, ",enospc_debug");
1499 if (btrfs_test_opt(info, AUTO_DEFRAG))
1500 seq_puts(seq, ",autodefrag");
1501 if (btrfs_test_opt(info, SKIP_BALANCE))
1502 seq_puts(seq, ",skip_balance");
1503 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1504 if (btrfs_test_opt(info, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1505 seq_puts(seq, ",check_int_data");
1506 else if (btrfs_test_opt(info, CHECK_INTEGRITY))
1507 seq_puts(seq, ",check_int");
1508 if (info->check_integrity_print_mask)
1509 seq_printf(seq, ",check_int_print_mask=%d",
1510 info->check_integrity_print_mask);
1512 if (info->metadata_ratio)
1513 seq_printf(seq, ",metadata_ratio=%u", info->metadata_ratio);
1514 if (btrfs_test_opt(info, PANIC_ON_FATAL_ERROR))
1515 seq_puts(seq, ",fatal_errors=panic");
1516 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1517 seq_printf(seq, ",commit=%u", info->commit_interval);
1518 #ifdef CONFIG_BTRFS_DEBUG
1519 if (btrfs_test_opt(info, FRAGMENT_DATA))
1520 seq_puts(seq, ",fragment=data");
1521 if (btrfs_test_opt(info, FRAGMENT_METADATA))
1522 seq_puts(seq, ",fragment=metadata");
1524 if (btrfs_test_opt(info, REF_VERIFY))
1525 seq_puts(seq, ",ref_verify");
1526 seq_printf(seq, ",subvolid=%llu",
1527 BTRFS_I(d_inode(dentry))->root->root_key.objectid);
1528 subvol_name = btrfs_get_subvol_name_from_objectid(info,
1529 BTRFS_I(d_inode(dentry))->root->root_key.objectid);
1530 if (!IS_ERR(subvol_name)) {
1531 seq_puts(seq, ",subvol=");
1532 seq_escape(seq, subvol_name, " \t\n\\");
1538 static int btrfs_test_super(struct super_block *s, void *data)
1540 struct btrfs_fs_info *p = data;
1541 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1543 return fs_info->fs_devices == p->fs_devices;
1546 static int btrfs_set_super(struct super_block *s, void *data)
1548 int err = set_anon_super(s, data);
1550 s->s_fs_info = data;
1555 * subvolumes are identified by ino 256
1557 static inline int is_subvolume_inode(struct inode *inode)
1559 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1564 static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid,
1565 struct vfsmount *mnt)
1567 struct dentry *root;
1571 if (!subvol_objectid) {
1572 ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb),
1575 root = ERR_PTR(ret);
1579 subvol_name = btrfs_get_subvol_name_from_objectid(
1580 btrfs_sb(mnt->mnt_sb), subvol_objectid);
1581 if (IS_ERR(subvol_name)) {
1582 root = ERR_CAST(subvol_name);
1589 root = mount_subtree(mnt, subvol_name);
1590 /* mount_subtree() drops our reference on the vfsmount. */
1593 if (!IS_ERR(root)) {
1594 struct super_block *s = root->d_sb;
1595 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1596 struct inode *root_inode = d_inode(root);
1597 u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid;
1600 if (!is_subvolume_inode(root_inode)) {
1601 btrfs_err(fs_info, "'%s' is not a valid subvolume",
1605 if (subvol_objectid && root_objectid != subvol_objectid) {
1607 * This will also catch a race condition where a
1608 * subvolume which was passed by ID is renamed and
1609 * another subvolume is renamed over the old location.
1612 "subvol '%s' does not match subvolid %llu",
1613 subvol_name, subvol_objectid);
1618 root = ERR_PTR(ret);
1619 deactivate_locked_super(s);
1630 * Find a superblock for the given device / mount point.
1632 * Note: This is based on mount_bdev from fs/super.c with a few additions
1633 * for multiple device setup. Make sure to keep it in sync.
1635 static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
1636 int flags, const char *device_name, void *data)
1638 struct block_device *bdev = NULL;
1639 struct super_block *s;
1640 struct btrfs_device *device = NULL;
1641 struct btrfs_fs_devices *fs_devices = NULL;
1642 struct btrfs_fs_info *fs_info = NULL;
1643 void *new_sec_opts = NULL;
1644 fmode_t mode = FMODE_READ;
1647 if (!(flags & SB_RDONLY))
1648 mode |= FMODE_WRITE;
1651 error = security_sb_eat_lsm_opts(data, &new_sec_opts);
1653 return ERR_PTR(error);
1657 * Setup a dummy root and fs_info for test/set super. This is because
1658 * we don't actually fill this stuff out until open_ctree, but we need
1659 * then open_ctree will properly initialize the file system specific
1660 * settings later. btrfs_init_fs_info initializes the static elements
1661 * of the fs_info (locks and such) to make cleanup easier if we find a
1662 * superblock with our given fs_devices later on at sget() time.
1664 fs_info = kvzalloc(sizeof(struct btrfs_fs_info), GFP_KERNEL);
1667 goto error_sec_opts;
1669 btrfs_init_fs_info(fs_info);
1671 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1672 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1673 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1678 mutex_lock(&uuid_mutex);
1679 error = btrfs_parse_device_options(data, mode, fs_type);
1681 mutex_unlock(&uuid_mutex);
1685 device = btrfs_scan_one_device(device_name, mode, fs_type);
1686 if (IS_ERR(device)) {
1687 mutex_unlock(&uuid_mutex);
1688 error = PTR_ERR(device);
1692 fs_devices = device->fs_devices;
1693 fs_info->fs_devices = fs_devices;
1695 error = btrfs_open_devices(fs_devices, mode, fs_type);
1696 mutex_unlock(&uuid_mutex);
1700 if (!(flags & SB_RDONLY) && fs_devices->rw_devices == 0) {
1702 goto error_close_devices;
1705 bdev = fs_devices->latest_bdev;
1706 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | SB_NOSEC,
1710 goto error_close_devices;
1714 btrfs_close_devices(fs_devices);
1715 btrfs_free_fs_info(fs_info);
1716 if ((flags ^ s->s_flags) & SB_RDONLY)
1719 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
1720 btrfs_sb(s)->bdev_holder = fs_type;
1721 if (!strstr(crc32c_impl(), "generic"))
1722 set_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags);
1723 error = btrfs_fill_super(s, fs_devices, data);
1726 error = security_sb_set_mnt_opts(s, new_sec_opts, 0, NULL);
1727 security_free_mnt_opts(&new_sec_opts);
1729 deactivate_locked_super(s);
1730 return ERR_PTR(error);
1733 return dget(s->s_root);
1735 error_close_devices:
1736 btrfs_close_devices(fs_devices);
1738 btrfs_free_fs_info(fs_info);
1740 security_free_mnt_opts(&new_sec_opts);
1741 return ERR_PTR(error);
1745 * Mount function which is called by VFS layer.
1747 * In order to allow mounting a subvolume directly, btrfs uses mount_subtree()
1748 * which needs vfsmount* of device's root (/). This means device's root has to
1749 * be mounted internally in any case.
1752 * 1. Parse subvol id related options for later use in mount_subvol().
1754 * 2. Mount device's root (/) by calling vfs_kern_mount().
1756 * NOTE: vfs_kern_mount() is used by VFS to call btrfs_mount() in the
1757 * first place. In order to avoid calling btrfs_mount() again, we use
1758 * different file_system_type which is not registered to VFS by
1759 * register_filesystem() (btrfs_root_fs_type). As a result,
1760 * btrfs_mount_root() is called. The return value will be used by
1761 * mount_subtree() in mount_subvol().
1763 * 3. Call mount_subvol() to get the dentry of subvolume. Since there is
1764 * "btrfs subvolume set-default", mount_subvol() is called always.
1766 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1767 const char *device_name, void *data)
1769 struct vfsmount *mnt_root;
1770 struct dentry *root;
1771 char *subvol_name = NULL;
1772 u64 subvol_objectid = 0;
1775 error = btrfs_parse_subvol_options(data, &subvol_name,
1779 return ERR_PTR(error);
1782 /* mount device's root (/) */
1783 mnt_root = vfs_kern_mount(&btrfs_root_fs_type, flags, device_name, data);
1784 if (PTR_ERR_OR_ZERO(mnt_root) == -EBUSY) {
1785 if (flags & SB_RDONLY) {
1786 mnt_root = vfs_kern_mount(&btrfs_root_fs_type,
1787 flags & ~SB_RDONLY, device_name, data);
1789 mnt_root = vfs_kern_mount(&btrfs_root_fs_type,
1790 flags | SB_RDONLY, device_name, data);
1791 if (IS_ERR(mnt_root)) {
1792 root = ERR_CAST(mnt_root);
1797 down_write(&mnt_root->mnt_sb->s_umount);
1798 error = btrfs_remount(mnt_root->mnt_sb, &flags, NULL);
1799 up_write(&mnt_root->mnt_sb->s_umount);
1801 root = ERR_PTR(error);
1808 if (IS_ERR(mnt_root)) {
1809 root = ERR_CAST(mnt_root);
1814 /* mount_subvol() will free subvol_name and mnt_root */
1815 root = mount_subvol(subvol_name, subvol_objectid, mnt_root);
1821 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1822 u32 new_pool_size, u32 old_pool_size)
1824 if (new_pool_size == old_pool_size)
1827 fs_info->thread_pool_size = new_pool_size;
1829 btrfs_info(fs_info, "resize thread pool %d -> %d",
1830 old_pool_size, new_pool_size);
1832 btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
1833 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
1834 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
1835 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
1836 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
1837 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
1839 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
1840 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
1841 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
1842 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size);
1843 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers,
1847 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1848 unsigned long old_opts, int flags)
1850 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1851 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1852 (flags & SB_RDONLY))) {
1853 /* wait for any defraggers to finish */
1854 wait_event(fs_info->transaction_wait,
1855 (atomic_read(&fs_info->defrag_running) == 0));
1856 if (flags & SB_RDONLY)
1857 sync_filesystem(fs_info->sb);
1861 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1862 unsigned long old_opts)
1864 const bool cache_opt = btrfs_test_opt(fs_info, SPACE_CACHE);
1867 * We need to cleanup all defragable inodes if the autodefragment is
1868 * close or the filesystem is read only.
1870 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1871 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || sb_rdonly(fs_info->sb))) {
1872 btrfs_cleanup_defrag_inodes(fs_info);
1875 /* If we toggled discard async */
1876 if (!btrfs_raw_test_opt(old_opts, DISCARD_ASYNC) &&
1877 btrfs_test_opt(fs_info, DISCARD_ASYNC))
1878 btrfs_discard_resume(fs_info);
1879 else if (btrfs_raw_test_opt(old_opts, DISCARD_ASYNC) &&
1880 !btrfs_test_opt(fs_info, DISCARD_ASYNC))
1881 btrfs_discard_cleanup(fs_info);
1883 /* If we toggled space cache */
1884 if (cache_opt != btrfs_free_space_cache_v1_active(fs_info))
1885 btrfs_set_free_space_cache_v1_active(fs_info, cache_opt);
1888 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1890 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1891 unsigned old_flags = sb->s_flags;
1892 unsigned long old_opts = fs_info->mount_opt;
1893 unsigned long old_compress_type = fs_info->compress_type;
1894 u64 old_max_inline = fs_info->max_inline;
1895 u32 old_thread_pool_size = fs_info->thread_pool_size;
1896 u32 old_metadata_ratio = fs_info->metadata_ratio;
1899 sync_filesystem(sb);
1900 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1903 void *new_sec_opts = NULL;
1905 ret = security_sb_eat_lsm_opts(data, &new_sec_opts);
1907 ret = security_sb_remount(sb, new_sec_opts);
1908 security_free_mnt_opts(&new_sec_opts);
1913 ret = btrfs_parse_options(fs_info, data, *flags);
1917 btrfs_remount_begin(fs_info, old_opts, *flags);
1918 btrfs_resize_thread_pool(fs_info,
1919 fs_info->thread_pool_size, old_thread_pool_size);
1921 if (btrfs_test_opt(fs_info, FREE_SPACE_TREE) !=
1922 btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
1923 (!sb_rdonly(sb) || (*flags & SB_RDONLY))) {
1925 "remount supports changing free space tree only from ro to rw");
1926 /* Make sure free space cache options match the state on disk */
1927 if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
1928 btrfs_set_opt(fs_info->mount_opt, FREE_SPACE_TREE);
1929 btrfs_clear_opt(fs_info->mount_opt, SPACE_CACHE);
1931 if (btrfs_free_space_cache_v1_active(fs_info)) {
1932 btrfs_clear_opt(fs_info->mount_opt, FREE_SPACE_TREE);
1933 btrfs_set_opt(fs_info->mount_opt, SPACE_CACHE);
1937 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1940 if (*flags & SB_RDONLY) {
1942 * this also happens on 'umount -rf' or on shutdown, when
1943 * the filesystem is busy.
1945 cancel_work_sync(&fs_info->async_reclaim_work);
1946 cancel_work_sync(&fs_info->async_data_reclaim_work);
1948 btrfs_discard_cleanup(fs_info);
1950 /* wait for the uuid_scan task to finish */
1951 down(&fs_info->uuid_tree_rescan_sem);
1952 /* avoid complains from lockdep et al. */
1953 up(&fs_info->uuid_tree_rescan_sem);
1955 btrfs_set_sb_rdonly(sb);
1958 * Setting SB_RDONLY will put the cleaner thread to
1959 * sleep at the next loop if it's already active.
1960 * If it's already asleep, we'll leave unused block
1961 * groups on disk until we're mounted read-write again
1962 * unless we clean them up here.
1964 btrfs_delete_unused_bgs(fs_info);
1967 * The cleaner task could be already running before we set the
1968 * flag BTRFS_FS_STATE_RO (and SB_RDONLY in the superblock).
1969 * We must make sure that after we finish the remount, i.e. after
1970 * we call btrfs_commit_super(), the cleaner can no longer start
1971 * a transaction - either because it was dropping a dead root,
1972 * running delayed iputs or deleting an unused block group (the
1973 * cleaner picked a block group from the list of unused block
1974 * groups before we were able to in the previous call to
1975 * btrfs_delete_unused_bgs()).
1977 wait_on_bit(&fs_info->flags, BTRFS_FS_CLEANER_RUNNING,
1978 TASK_UNINTERRUPTIBLE);
1981 * We've set the superblock to RO mode, so we might have made
1982 * the cleaner task sleep without running all pending delayed
1983 * iputs. Go through all the delayed iputs here, so that if an
1984 * unmount happens without remounting RW we don't end up at
1985 * finishing close_ctree() with a non-empty list of delayed
1988 btrfs_run_delayed_iputs(fs_info);
1990 btrfs_dev_replace_suspend_for_unmount(fs_info);
1991 btrfs_scrub_cancel(fs_info);
1992 btrfs_pause_balance(fs_info);
1995 * Pause the qgroup rescan worker if it is running. We don't want
1996 * it to be still running after we are in RO mode, as after that,
1997 * by the time we unmount, it might have left a transaction open,
1998 * so we would leak the transaction and/or crash.
2000 btrfs_qgroup_wait_for_completion(fs_info, false);
2002 ret = btrfs_commit_super(fs_info);
2006 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
2008 "Remounting read-write after error is not allowed");
2012 if (fs_info->fs_devices->rw_devices == 0) {
2017 if (!btrfs_check_rw_degradable(fs_info, NULL)) {
2019 "too many missing devices, writable remount is not allowed");
2024 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
2026 "mount required to replay tree-log, cannot remount read-write");
2030 if (fs_info->sectorsize < PAGE_SIZE) {
2032 "read-write mount is not yet allowed for sectorsize %u page size %lu",
2033 fs_info->sectorsize, PAGE_SIZE);
2039 * NOTE: when remounting with a change that does writes, don't
2040 * put it anywhere above this point, as we are not sure to be
2041 * safe to write until we pass the above checks.
2043 ret = btrfs_start_pre_rw_mount(fs_info);
2047 btrfs_clear_sb_rdonly(sb);
2049 set_bit(BTRFS_FS_OPEN, &fs_info->flags);
2053 * We need to set SB_I_VERSION here otherwise it'll get cleared by VFS,
2054 * since the absence of the flag means it can be toggled off by remount.
2056 *flags |= SB_I_VERSION;
2058 wake_up_process(fs_info->transaction_kthread);
2059 btrfs_remount_cleanup(fs_info, old_opts);
2060 btrfs_clear_oneshot_options(fs_info);
2061 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
2066 /* We've hit an error - don't reset SB_RDONLY */
2068 old_flags |= SB_RDONLY;
2069 if (!(old_flags & SB_RDONLY))
2070 clear_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state);
2071 sb->s_flags = old_flags;
2072 fs_info->mount_opt = old_opts;
2073 fs_info->compress_type = old_compress_type;
2074 fs_info->max_inline = old_max_inline;
2075 btrfs_resize_thread_pool(fs_info,
2076 old_thread_pool_size, fs_info->thread_pool_size);
2077 fs_info->metadata_ratio = old_metadata_ratio;
2078 btrfs_remount_cleanup(fs_info, old_opts);
2079 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
2084 /* Used to sort the devices by max_avail(descending sort) */
2085 static inline int btrfs_cmp_device_free_bytes(const void *dev_info1,
2086 const void *dev_info2)
2088 if (((struct btrfs_device_info *)dev_info1)->max_avail >
2089 ((struct btrfs_device_info *)dev_info2)->max_avail)
2091 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
2092 ((struct btrfs_device_info *)dev_info2)->max_avail)
2099 * sort the devices by max_avail, in which max free extent size of each device
2100 * is stored.(Descending Sort)
2102 static inline void btrfs_descending_sort_devices(
2103 struct btrfs_device_info *devices,
2106 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
2107 btrfs_cmp_device_free_bytes, NULL);
2111 * The helper to calc the free space on the devices that can be used to store
2114 static inline int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
2117 struct btrfs_device_info *devices_info;
2118 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2119 struct btrfs_device *device;
2122 u64 min_stripe_size;
2123 int num_stripes = 1;
2124 int i = 0, nr_devices;
2125 const struct btrfs_raid_attr *rattr;
2128 * We aren't under the device list lock, so this is racy-ish, but good
2129 * enough for our purposes.
2131 nr_devices = fs_info->fs_devices->open_devices;
2134 nr_devices = fs_info->fs_devices->open_devices;
2142 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
2147 /* calc min stripe number for data space allocation */
2148 type = btrfs_data_alloc_profile(fs_info);
2149 rattr = &btrfs_raid_array[btrfs_bg_flags_to_raid_index(type)];
2151 if (type & BTRFS_BLOCK_GROUP_RAID0)
2152 num_stripes = nr_devices;
2153 else if (type & BTRFS_BLOCK_GROUP_RAID1)
2155 else if (type & BTRFS_BLOCK_GROUP_RAID1C3)
2157 else if (type & BTRFS_BLOCK_GROUP_RAID1C4)
2159 else if (type & BTRFS_BLOCK_GROUP_RAID10)
2162 /* Adjust for more than 1 stripe per device */
2163 min_stripe_size = rattr->dev_stripes * BTRFS_STRIPE_LEN;
2166 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
2167 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
2168 &device->dev_state) ||
2170 test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
2173 if (i >= nr_devices)
2176 avail_space = device->total_bytes - device->bytes_used;
2178 /* align with stripe_len */
2179 avail_space = rounddown(avail_space, BTRFS_STRIPE_LEN);
2182 * In order to avoid overwriting the superblock on the drive,
2183 * btrfs starts at an offset of at least 1MB when doing chunk
2186 * This ensures we have at least min_stripe_size free space
2187 * after excluding 1MB.
2189 if (avail_space <= SZ_1M + min_stripe_size)
2192 avail_space -= SZ_1M;
2194 devices_info[i].dev = device;
2195 devices_info[i].max_avail = avail_space;
2203 btrfs_descending_sort_devices(devices_info, nr_devices);
2207 while (nr_devices >= rattr->devs_min) {
2208 num_stripes = min(num_stripes, nr_devices);
2210 if (devices_info[i].max_avail >= min_stripe_size) {
2214 avail_space += devices_info[i].max_avail * num_stripes;
2215 alloc_size = devices_info[i].max_avail;
2216 for (j = i + 1 - num_stripes; j <= i; j++)
2217 devices_info[j].max_avail -= alloc_size;
2223 kfree(devices_info);
2224 *free_bytes = avail_space;
2229 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles.
2231 * If there's a redundant raid level at DATA block groups, use the respective
2232 * multiplier to scale the sizes.
2234 * Unused device space usage is based on simulating the chunk allocator
2235 * algorithm that respects the device sizes and order of allocations. This is
2236 * a close approximation of the actual use but there are other factors that may
2237 * change the result (like a new metadata chunk).
2239 * If metadata is exhausted, f_bavail will be 0.
2241 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
2243 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
2244 struct btrfs_super_block *disk_super = fs_info->super_copy;
2245 struct btrfs_space_info *found;
2247 u64 total_free_data = 0;
2248 u64 total_free_meta = 0;
2249 u32 bits = fs_info->sectorsize_bits;
2250 __be32 *fsid = (__be32 *)fs_info->fs_devices->fsid;
2251 unsigned factor = 1;
2252 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
2257 list_for_each_entry(found, &fs_info->space_info, list) {
2258 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
2261 total_free_data += found->disk_total - found->disk_used;
2263 btrfs_account_ro_block_groups_free_space(found);
2265 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
2266 if (!list_empty(&found->block_groups[i]))
2267 factor = btrfs_bg_type_to_factor(
2268 btrfs_raid_array[i].bg_flag);
2273 * Metadata in mixed block goup profiles are accounted in data
2275 if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) {
2276 if (found->flags & BTRFS_BLOCK_GROUP_DATA)
2279 total_free_meta += found->disk_total -
2283 total_used += found->disk_used;
2286 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor);
2287 buf->f_blocks >>= bits;
2288 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits);
2290 /* Account global block reserve as used, it's in logical size already */
2291 spin_lock(&block_rsv->lock);
2292 /* Mixed block groups accounting is not byte-accurate, avoid overflow */
2293 if (buf->f_bfree >= block_rsv->size >> bits)
2294 buf->f_bfree -= block_rsv->size >> bits;
2297 spin_unlock(&block_rsv->lock);
2299 buf->f_bavail = div_u64(total_free_data, factor);
2300 ret = btrfs_calc_avail_data_space(fs_info, &total_free_data);
2303 buf->f_bavail += div_u64(total_free_data, factor);
2304 buf->f_bavail = buf->f_bavail >> bits;
2307 * We calculate the remaining metadata space minus global reserve. If
2308 * this is (supposedly) smaller than zero, there's no space. But this
2309 * does not hold in practice, the exhausted state happens where's still
2310 * some positive delta. So we apply some guesswork and compare the
2311 * delta to a 4M threshold. (Practically observed delta was ~2M.)
2313 * We probably cannot calculate the exact threshold value because this
2314 * depends on the internal reservations requested by various
2315 * operations, so some operations that consume a few metadata will
2316 * succeed even if the Avail is zero. But this is better than the other
2322 * We only want to claim there's no available space if we can no longer
2323 * allocate chunks for our metadata profile and our global reserve will
2324 * not fit in the free metadata space. If we aren't ->full then we
2325 * still can allocate chunks and thus are fine using the currently
2326 * calculated f_bavail.
2328 if (!mixed && block_rsv->space_info->full &&
2329 total_free_meta - thresh < block_rsv->size)
2332 buf->f_type = BTRFS_SUPER_MAGIC;
2333 buf->f_bsize = dentry->d_sb->s_blocksize;
2334 buf->f_namelen = BTRFS_NAME_LEN;
2336 /* We treat it as constant endianness (it doesn't matter _which_)
2337 because we want the fsid to come out the same whether mounted
2338 on a big-endian or little-endian host */
2339 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
2340 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
2341 /* Mask in the root object ID too, to disambiguate subvols */
2342 buf->f_fsid.val[0] ^=
2343 BTRFS_I(d_inode(dentry))->root->root_key.objectid >> 32;
2344 buf->f_fsid.val[1] ^=
2345 BTRFS_I(d_inode(dentry))->root->root_key.objectid;
2350 static void btrfs_kill_super(struct super_block *sb)
2352 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2353 kill_anon_super(sb);
2354 btrfs_free_fs_info(fs_info);
2357 static struct file_system_type btrfs_fs_type = {
2358 .owner = THIS_MODULE,
2360 .mount = btrfs_mount,
2361 .kill_sb = btrfs_kill_super,
2362 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2365 static struct file_system_type btrfs_root_fs_type = {
2366 .owner = THIS_MODULE,
2368 .mount = btrfs_mount_root,
2369 .kill_sb = btrfs_kill_super,
2370 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2373 MODULE_ALIAS_FS("btrfs");
2375 static int btrfs_control_open(struct inode *inode, struct file *file)
2378 * The control file's private_data is used to hold the
2379 * transaction when it is started and is used to keep
2380 * track of whether a transaction is already in progress.
2382 file->private_data = NULL;
2387 * Used by /dev/btrfs-control for devices ioctls.
2389 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
2392 struct btrfs_ioctl_vol_args *vol;
2393 struct btrfs_device *device = NULL;
2396 if (!capable(CAP_SYS_ADMIN))
2399 vol = memdup_user((void __user *)arg, sizeof(*vol));
2401 return PTR_ERR(vol);
2402 vol->name[BTRFS_PATH_NAME_MAX] = '\0';
2405 case BTRFS_IOC_SCAN_DEV:
2406 mutex_lock(&uuid_mutex);
2407 device = btrfs_scan_one_device(vol->name, FMODE_READ,
2408 &btrfs_root_fs_type);
2409 ret = PTR_ERR_OR_ZERO(device);
2410 mutex_unlock(&uuid_mutex);
2412 case BTRFS_IOC_FORGET_DEV:
2413 ret = btrfs_forget_devices(vol->name);
2415 case BTRFS_IOC_DEVICES_READY:
2416 mutex_lock(&uuid_mutex);
2417 device = btrfs_scan_one_device(vol->name, FMODE_READ,
2418 &btrfs_root_fs_type);
2419 if (IS_ERR(device)) {
2420 mutex_unlock(&uuid_mutex);
2421 ret = PTR_ERR(device);
2424 ret = !(device->fs_devices->num_devices ==
2425 device->fs_devices->total_devices);
2426 mutex_unlock(&uuid_mutex);
2428 case BTRFS_IOC_GET_SUPPORTED_FEATURES:
2429 ret = btrfs_ioctl_get_supported_features((void __user*)arg);
2437 static int btrfs_freeze(struct super_block *sb)
2439 struct btrfs_trans_handle *trans;
2440 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2441 struct btrfs_root *root = fs_info->tree_root;
2443 set_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2445 * We don't need a barrier here, we'll wait for any transaction that
2446 * could be in progress on other threads (and do delayed iputs that
2447 * we want to avoid on a frozen filesystem), or do the commit
2450 trans = btrfs_attach_transaction_barrier(root);
2451 if (IS_ERR(trans)) {
2452 /* no transaction, don't bother */
2453 if (PTR_ERR(trans) == -ENOENT)
2455 return PTR_ERR(trans);
2457 return btrfs_commit_transaction(trans);
2460 static int btrfs_unfreeze(struct super_block *sb)
2462 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2464 clear_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2468 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
2470 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
2471 struct btrfs_device *dev, *first_dev = NULL;
2474 * Lightweight locking of the devices. We should not need
2475 * device_list_mutex here as we only read the device data and the list
2476 * is protected by RCU. Even if a device is deleted during the list
2477 * traversals, we'll get valid data, the freeing callback will wait at
2478 * least until the rcu_read_unlock.
2481 list_for_each_entry_rcu(dev, &fs_info->fs_devices->devices, dev_list) {
2482 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
2486 if (!first_dev || dev->devid < first_dev->devid)
2491 seq_escape(m, rcu_str_deref(first_dev->name), " \t\n\\");
2498 static const struct super_operations btrfs_super_ops = {
2499 .drop_inode = btrfs_drop_inode,
2500 .evict_inode = btrfs_evict_inode,
2501 .put_super = btrfs_put_super,
2502 .sync_fs = btrfs_sync_fs,
2503 .show_options = btrfs_show_options,
2504 .show_devname = btrfs_show_devname,
2505 .alloc_inode = btrfs_alloc_inode,
2506 .destroy_inode = btrfs_destroy_inode,
2507 .free_inode = btrfs_free_inode,
2508 .statfs = btrfs_statfs,
2509 .remount_fs = btrfs_remount,
2510 .freeze_fs = btrfs_freeze,
2511 .unfreeze_fs = btrfs_unfreeze,
2514 static const struct file_operations btrfs_ctl_fops = {
2515 .open = btrfs_control_open,
2516 .unlocked_ioctl = btrfs_control_ioctl,
2517 .compat_ioctl = compat_ptr_ioctl,
2518 .owner = THIS_MODULE,
2519 .llseek = noop_llseek,
2522 static struct miscdevice btrfs_misc = {
2523 .minor = BTRFS_MINOR,
2524 .name = "btrfs-control",
2525 .fops = &btrfs_ctl_fops
2528 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
2529 MODULE_ALIAS("devname:btrfs-control");
2531 static int __init btrfs_interface_init(void)
2533 return misc_register(&btrfs_misc);
2536 static __cold void btrfs_interface_exit(void)
2538 misc_deregister(&btrfs_misc);
2541 static void __init btrfs_print_mod_info(void)
2543 static const char options[] = ""
2544 #ifdef CONFIG_BTRFS_DEBUG
2547 #ifdef CONFIG_BTRFS_ASSERT
2550 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2551 ", integrity-checker=on"
2553 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
2556 #ifdef CONFIG_BLK_DEV_ZONED
2562 pr_info("Btrfs loaded, crc32c=%s%s\n", crc32c_impl(), options);
2565 static int __init init_btrfs_fs(void)
2571 err = btrfs_init_sysfs();
2575 btrfs_init_compress();
2577 err = btrfs_init_cachep();
2581 err = extent_io_init();
2585 err = extent_state_cache_init();
2587 goto free_extent_io;
2589 err = extent_map_init();
2591 goto free_extent_state_cache;
2593 err = ordered_data_init();
2595 goto free_extent_map;
2597 err = btrfs_delayed_inode_init();
2599 goto free_ordered_data;
2601 err = btrfs_auto_defrag_init();
2603 goto free_delayed_inode;
2605 err = btrfs_delayed_ref_init();
2607 goto free_auto_defrag;
2609 err = btrfs_prelim_ref_init();
2611 goto free_delayed_ref;
2613 err = btrfs_end_io_wq_init();
2615 goto free_prelim_ref;
2617 err = btrfs_interface_init();
2619 goto free_end_io_wq;
2621 btrfs_print_mod_info();
2623 err = btrfs_run_sanity_tests();
2625 goto unregister_ioctl;
2627 err = register_filesystem(&btrfs_fs_type);
2629 goto unregister_ioctl;
2634 btrfs_interface_exit();
2636 btrfs_end_io_wq_exit();
2638 btrfs_prelim_ref_exit();
2640 btrfs_delayed_ref_exit();
2642 btrfs_auto_defrag_exit();
2644 btrfs_delayed_inode_exit();
2646 ordered_data_exit();
2649 free_extent_state_cache:
2650 extent_state_cache_exit();
2654 btrfs_destroy_cachep();
2656 btrfs_exit_compress();
2662 static void __exit exit_btrfs_fs(void)
2664 btrfs_destroy_cachep();
2665 btrfs_delayed_ref_exit();
2666 btrfs_auto_defrag_exit();
2667 btrfs_delayed_inode_exit();
2668 btrfs_prelim_ref_exit();
2669 ordered_data_exit();
2671 extent_state_cache_exit();
2673 btrfs_interface_exit();
2674 btrfs_end_io_wq_exit();
2675 unregister_filesystem(&btrfs_fs_type);
2677 btrfs_cleanup_fs_uuids();
2678 btrfs_exit_compress();
2681 late_initcall(init_btrfs_fs);
2682 module_exit(exit_btrfs_fs)
2684 MODULE_LICENSE("GPL");
2685 MODULE_SOFTDEP("pre: crc32c");
2686 MODULE_SOFTDEP("pre: xxhash64");
2687 MODULE_SOFTDEP("pre: sha256");
2688 MODULE_SOFTDEP("pre: blake2b-256");