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);
255 #if BITS_PER_LONG == 32
256 void __cold btrfs_warn_32bit_limit(struct btrfs_fs_info *fs_info)
258 if (!test_and_set_bit(BTRFS_FS_32BIT_WARN, &fs_info->flags)) {
259 btrfs_warn(fs_info, "reaching 32bit limit for logical addresses");
261 "due to page cache limit on 32bit systems, btrfs can't access metadata at or beyond %lluT",
262 BTRFS_32BIT_MAX_FILE_SIZE >> 40);
264 "please consider upgrading to 64bit kernel/hardware");
268 void __cold btrfs_err_32bit_limit(struct btrfs_fs_info *fs_info)
270 if (!test_and_set_bit(BTRFS_FS_32BIT_ERROR, &fs_info->flags)) {
271 btrfs_err(fs_info, "reached 32bit limit for logical addresses");
273 "due to page cache limit on 32bit systems, metadata beyond %lluT can't be accessed",
274 BTRFS_32BIT_MAX_FILE_SIZE >> 40);
276 "please consider upgrading to 64bit kernel/hardware");
282 * We only mark the transaction aborted and then set the file system read-only.
283 * This will prevent new transactions from starting or trying to join this
286 * This means that error recovery at the call site is limited to freeing
287 * any local memory allocations and passing the error code up without
288 * further cleanup. The transaction should complete as it normally would
289 * in the call path but will return -EIO.
291 * We'll complete the cleanup in btrfs_end_transaction and
292 * btrfs_commit_transaction.
295 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
296 const char *function,
297 unsigned int line, int errno)
299 struct btrfs_fs_info *fs_info = trans->fs_info;
301 WRITE_ONCE(trans->aborted, errno);
302 WRITE_ONCE(trans->transaction->aborted, errno);
303 /* Wake up anybody who may be waiting on this transaction */
304 wake_up(&fs_info->transaction_wait);
305 wake_up(&fs_info->transaction_blocked_wait);
306 __btrfs_handle_fs_error(fs_info, function, line, errno, NULL);
309 * __btrfs_panic decodes unexpected, fatal errors from the caller,
310 * issues an alert, and either panics or BUGs, depending on mount options.
313 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
314 unsigned int line, int errno, const char *fmt, ...)
316 char *s_id = "<unknown>";
318 struct va_format vaf = { .fmt = fmt };
322 s_id = fs_info->sb->s_id;
327 errstr = btrfs_decode_error(errno);
328 if (fs_info && (btrfs_test_opt(fs_info, PANIC_ON_FATAL_ERROR)))
329 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
330 s_id, function, line, &vaf, errno, errstr);
332 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
333 function, line, &vaf, errno, errstr);
335 /* Caller calls BUG() */
338 static void btrfs_put_super(struct super_block *sb)
340 close_ctree(btrfs_sb(sb));
349 Opt_compress_force_type,
354 Opt_flushoncommit, Opt_noflushoncommit,
356 Opt_barrier, Opt_nobarrier,
357 Opt_datacow, Opt_nodatacow,
358 Opt_datasum, Opt_nodatasum,
359 Opt_defrag, Opt_nodefrag,
360 Opt_discard, Opt_nodiscard,
364 Opt_rescan_uuid_tree,
366 Opt_space_cache, Opt_no_space_cache,
367 Opt_space_cache_version,
369 Opt_ssd_spread, Opt_nossd_spread,
374 Opt_treelog, Opt_notreelog,
375 Opt_user_subvol_rm_allowed,
385 /* Deprecated options */
387 Opt_inode_cache, Opt_noinode_cache,
389 /* Debugging options */
391 Opt_check_integrity_including_extent_data,
392 Opt_check_integrity_print_mask,
393 Opt_enospc_debug, Opt_noenospc_debug,
394 #ifdef CONFIG_BTRFS_DEBUG
395 Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all,
397 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
403 static const match_table_t tokens = {
405 {Opt_noacl, "noacl"},
406 {Opt_clear_cache, "clear_cache"},
407 {Opt_commit_interval, "commit=%u"},
408 {Opt_compress, "compress"},
409 {Opt_compress_type, "compress=%s"},
410 {Opt_compress_force, "compress-force"},
411 {Opt_compress_force_type, "compress-force=%s"},
412 {Opt_degraded, "degraded"},
413 {Opt_device, "device=%s"},
414 {Opt_fatal_errors, "fatal_errors=%s"},
415 {Opt_flushoncommit, "flushoncommit"},
416 {Opt_noflushoncommit, "noflushoncommit"},
417 {Opt_inode_cache, "inode_cache"},
418 {Opt_noinode_cache, "noinode_cache"},
419 {Opt_max_inline, "max_inline=%s"},
420 {Opt_barrier, "barrier"},
421 {Opt_nobarrier, "nobarrier"},
422 {Opt_datacow, "datacow"},
423 {Opt_nodatacow, "nodatacow"},
424 {Opt_datasum, "datasum"},
425 {Opt_nodatasum, "nodatasum"},
426 {Opt_defrag, "autodefrag"},
427 {Opt_nodefrag, "noautodefrag"},
428 {Opt_discard, "discard"},
429 {Opt_discard_mode, "discard=%s"},
430 {Opt_nodiscard, "nodiscard"},
431 {Opt_norecovery, "norecovery"},
432 {Opt_ratio, "metadata_ratio=%u"},
433 {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
434 {Opt_skip_balance, "skip_balance"},
435 {Opt_space_cache, "space_cache"},
436 {Opt_no_space_cache, "nospace_cache"},
437 {Opt_space_cache_version, "space_cache=%s"},
439 {Opt_nossd, "nossd"},
440 {Opt_ssd_spread, "ssd_spread"},
441 {Opt_nossd_spread, "nossd_spread"},
442 {Opt_subvol, "subvol=%s"},
443 {Opt_subvol_empty, "subvol="},
444 {Opt_subvolid, "subvolid=%s"},
445 {Opt_thread_pool, "thread_pool=%u"},
446 {Opt_treelog, "treelog"},
447 {Opt_notreelog, "notreelog"},
448 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
451 {Opt_rescue, "rescue=%s"},
452 /* Deprecated, with alias rescue=nologreplay */
453 {Opt_nologreplay, "nologreplay"},
454 /* Deprecated, with alias rescue=usebackuproot */
455 {Opt_usebackuproot, "usebackuproot"},
457 /* Deprecated options */
458 {Opt_recovery, "recovery"},
460 /* Debugging options */
461 {Opt_check_integrity, "check_int"},
462 {Opt_check_integrity_including_extent_data, "check_int_data"},
463 {Opt_check_integrity_print_mask, "check_int_print_mask=%u"},
464 {Opt_enospc_debug, "enospc_debug"},
465 {Opt_noenospc_debug, "noenospc_debug"},
466 #ifdef CONFIG_BTRFS_DEBUG
467 {Opt_fragment_data, "fragment=data"},
468 {Opt_fragment_metadata, "fragment=metadata"},
469 {Opt_fragment_all, "fragment=all"},
471 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
472 {Opt_ref_verify, "ref_verify"},
477 static const match_table_t rescue_tokens = {
478 {Opt_usebackuproot, "usebackuproot"},
479 {Opt_nologreplay, "nologreplay"},
480 {Opt_ignorebadroots, "ignorebadroots"},
481 {Opt_ignorebadroots, "ibadroots"},
482 {Opt_ignoredatacsums, "ignoredatacsums"},
483 {Opt_ignoredatacsums, "idatacsums"},
484 {Opt_rescue_all, "all"},
488 static bool check_ro_option(struct btrfs_fs_info *fs_info, unsigned long opt,
489 const char *opt_name)
491 if (fs_info->mount_opt & opt) {
492 btrfs_err(fs_info, "%s must be used with ro mount option",
499 static int parse_rescue_options(struct btrfs_fs_info *info, const char *options)
504 substring_t args[MAX_OPT_ARGS];
507 opts = kstrdup(options, GFP_KERNEL);
512 while ((p = strsep(&opts, ":")) != NULL) {
517 token = match_token(p, rescue_tokens, args);
519 case Opt_usebackuproot:
521 "trying to use backup root at mount time");
522 btrfs_set_opt(info->mount_opt, USEBACKUPROOT);
524 case Opt_nologreplay:
525 btrfs_set_and_info(info, NOLOGREPLAY,
526 "disabling log replay at mount time");
528 case Opt_ignorebadroots:
529 btrfs_set_and_info(info, IGNOREBADROOTS,
530 "ignoring bad roots");
532 case Opt_ignoredatacsums:
533 btrfs_set_and_info(info, IGNOREDATACSUMS,
534 "ignoring data csums");
537 btrfs_info(info, "enabling all of the rescue options");
538 btrfs_set_and_info(info, IGNOREDATACSUMS,
539 "ignoring data csums");
540 btrfs_set_and_info(info, IGNOREBADROOTS,
541 "ignoring bad roots");
542 btrfs_set_and_info(info, NOLOGREPLAY,
543 "disabling log replay at mount time");
546 btrfs_info(info, "unrecognized rescue option '%s'", p);
560 * Regular mount options parser. Everything that is needed only when
561 * reading in a new superblock is parsed here.
562 * XXX JDM: This needs to be cleaned up for remount.
564 int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
565 unsigned long new_flags)
567 substring_t args[MAX_OPT_ARGS];
572 bool compress_force = false;
573 enum btrfs_compression_type saved_compress_type;
574 int saved_compress_level;
575 bool saved_compress_force;
578 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
579 btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
580 else if (btrfs_free_space_cache_v1_active(info)) {
581 if (btrfs_is_zoned(info)) {
583 "zoned: clearing existing space cache");
584 btrfs_set_super_cache_generation(info->super_copy, 0);
586 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
591 * Even the options are empty, we still need to do extra check
597 while ((p = strsep(&options, ",")) != NULL) {
602 token = match_token(p, tokens, args);
605 btrfs_info(info, "allowing degraded mounts");
606 btrfs_set_opt(info->mount_opt, DEGRADED);
609 case Opt_subvol_empty:
613 * These are parsed by btrfs_parse_subvol_options or
614 * btrfs_parse_device_options and can be ignored here.
618 btrfs_set_and_info(info, NODATASUM,
619 "setting nodatasum");
622 if (btrfs_test_opt(info, NODATASUM)) {
623 if (btrfs_test_opt(info, NODATACOW))
625 "setting datasum, datacow enabled");
627 btrfs_info(info, "setting datasum");
629 btrfs_clear_opt(info->mount_opt, NODATACOW);
630 btrfs_clear_opt(info->mount_opt, NODATASUM);
633 if (!btrfs_test_opt(info, NODATACOW)) {
634 if (!btrfs_test_opt(info, COMPRESS) ||
635 !btrfs_test_opt(info, FORCE_COMPRESS)) {
637 "setting nodatacow, compression disabled");
639 btrfs_info(info, "setting nodatacow");
642 btrfs_clear_opt(info->mount_opt, COMPRESS);
643 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
644 btrfs_set_opt(info->mount_opt, NODATACOW);
645 btrfs_set_opt(info->mount_opt, NODATASUM);
648 btrfs_clear_and_info(info, NODATACOW,
651 case Opt_compress_force:
652 case Opt_compress_force_type:
653 compress_force = true;
656 case Opt_compress_type:
657 saved_compress_type = btrfs_test_opt(info,
659 info->compress_type : BTRFS_COMPRESS_NONE;
660 saved_compress_force =
661 btrfs_test_opt(info, FORCE_COMPRESS);
662 saved_compress_level = info->compress_level;
663 if (token == Opt_compress ||
664 token == Opt_compress_force ||
665 strncmp(args[0].from, "zlib", 4) == 0) {
666 compress_type = "zlib";
668 info->compress_type = BTRFS_COMPRESS_ZLIB;
669 info->compress_level = BTRFS_ZLIB_DEFAULT_LEVEL;
671 * args[0] contains uninitialized data since
672 * for these tokens we don't expect any
675 if (token != Opt_compress &&
676 token != Opt_compress_force)
677 info->compress_level =
678 btrfs_compress_str2level(
681 btrfs_set_opt(info->mount_opt, COMPRESS);
682 btrfs_clear_opt(info->mount_opt, NODATACOW);
683 btrfs_clear_opt(info->mount_opt, NODATASUM);
685 } else if (strncmp(args[0].from, "lzo", 3) == 0) {
686 compress_type = "lzo";
687 info->compress_type = BTRFS_COMPRESS_LZO;
688 info->compress_level = 0;
689 btrfs_set_opt(info->mount_opt, COMPRESS);
690 btrfs_clear_opt(info->mount_opt, NODATACOW);
691 btrfs_clear_opt(info->mount_opt, NODATASUM);
692 btrfs_set_fs_incompat(info, COMPRESS_LZO);
694 } else if (strncmp(args[0].from, "zstd", 4) == 0) {
695 compress_type = "zstd";
696 info->compress_type = BTRFS_COMPRESS_ZSTD;
697 info->compress_level =
698 btrfs_compress_str2level(
701 btrfs_set_opt(info->mount_opt, COMPRESS);
702 btrfs_clear_opt(info->mount_opt, NODATACOW);
703 btrfs_clear_opt(info->mount_opt, NODATASUM);
704 btrfs_set_fs_incompat(info, COMPRESS_ZSTD);
706 } else if (strncmp(args[0].from, "no", 2) == 0) {
707 compress_type = "no";
708 info->compress_level = 0;
709 info->compress_type = 0;
710 btrfs_clear_opt(info->mount_opt, COMPRESS);
711 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
712 compress_force = false;
719 if (compress_force) {
720 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
723 * If we remount from compress-force=xxx to
724 * compress=xxx, we need clear FORCE_COMPRESS
725 * flag, otherwise, there is no way for users
726 * to disable forcible compression separately.
728 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
730 if (no_compress == 1) {
731 btrfs_info(info, "use no compression");
732 } else if ((info->compress_type != saved_compress_type) ||
733 (compress_force != saved_compress_force) ||
734 (info->compress_level != saved_compress_level)) {
735 btrfs_info(info, "%s %s compression, level %d",
736 (compress_force) ? "force" : "use",
737 compress_type, info->compress_level);
739 compress_force = false;
742 btrfs_set_and_info(info, SSD,
743 "enabling ssd optimizations");
744 btrfs_clear_opt(info->mount_opt, NOSSD);
747 btrfs_set_and_info(info, SSD,
748 "enabling ssd optimizations");
749 btrfs_set_and_info(info, SSD_SPREAD,
750 "using spread ssd allocation scheme");
751 btrfs_clear_opt(info->mount_opt, NOSSD);
754 btrfs_set_opt(info->mount_opt, NOSSD);
755 btrfs_clear_and_info(info, SSD,
756 "not using ssd optimizations");
758 case Opt_nossd_spread:
759 btrfs_clear_and_info(info, SSD_SPREAD,
760 "not using spread ssd allocation scheme");
763 btrfs_clear_and_info(info, NOBARRIER,
764 "turning on barriers");
767 btrfs_set_and_info(info, NOBARRIER,
768 "turning off barriers");
770 case Opt_thread_pool:
771 ret = match_int(&args[0], &intarg);
774 } else if (intarg == 0) {
778 info->thread_pool_size = intarg;
781 num = match_strdup(&args[0]);
783 info->max_inline = memparse(num, NULL);
786 if (info->max_inline) {
787 info->max_inline = min_t(u64,
791 btrfs_info(info, "max_inline at %llu",
799 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
800 info->sb->s_flags |= SB_POSIXACL;
803 btrfs_err(info, "support for ACL not compiled in!");
808 info->sb->s_flags &= ~SB_POSIXACL;
811 btrfs_set_and_info(info, NOTREELOG,
812 "disabling tree log");
815 btrfs_clear_and_info(info, NOTREELOG,
816 "enabling tree log");
819 case Opt_nologreplay:
821 "'nologreplay' is deprecated, use 'rescue=nologreplay' instead");
822 btrfs_set_and_info(info, NOLOGREPLAY,
823 "disabling log replay at mount time");
825 case Opt_flushoncommit:
826 btrfs_set_and_info(info, FLUSHONCOMMIT,
827 "turning on flush-on-commit");
829 case Opt_noflushoncommit:
830 btrfs_clear_and_info(info, FLUSHONCOMMIT,
831 "turning off flush-on-commit");
834 ret = match_int(&args[0], &intarg);
837 info->metadata_ratio = intarg;
838 btrfs_info(info, "metadata ratio %u",
839 info->metadata_ratio);
842 case Opt_discard_mode:
843 if (token == Opt_discard ||
844 strcmp(args[0].from, "sync") == 0) {
845 btrfs_clear_opt(info->mount_opt, DISCARD_ASYNC);
846 btrfs_set_and_info(info, DISCARD_SYNC,
847 "turning on sync discard");
848 } else if (strcmp(args[0].from, "async") == 0) {
849 btrfs_clear_opt(info->mount_opt, DISCARD_SYNC);
850 btrfs_set_and_info(info, DISCARD_ASYNC,
851 "turning on async discard");
858 btrfs_clear_and_info(info, DISCARD_SYNC,
859 "turning off discard");
860 btrfs_clear_and_info(info, DISCARD_ASYNC,
861 "turning off async discard");
863 case Opt_space_cache:
864 case Opt_space_cache_version:
865 if (token == Opt_space_cache ||
866 strcmp(args[0].from, "v1") == 0) {
867 btrfs_clear_opt(info->mount_opt,
869 btrfs_set_and_info(info, SPACE_CACHE,
870 "enabling disk space caching");
871 } else if (strcmp(args[0].from, "v2") == 0) {
872 btrfs_clear_opt(info->mount_opt,
874 btrfs_set_and_info(info, FREE_SPACE_TREE,
875 "enabling free space tree");
881 case Opt_rescan_uuid_tree:
882 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
884 case Opt_no_space_cache:
885 if (btrfs_test_opt(info, SPACE_CACHE)) {
886 btrfs_clear_and_info(info, SPACE_CACHE,
887 "disabling disk space caching");
889 if (btrfs_test_opt(info, FREE_SPACE_TREE)) {
890 btrfs_clear_and_info(info, FREE_SPACE_TREE,
891 "disabling free space tree");
894 case Opt_inode_cache:
895 case Opt_noinode_cache:
897 "the 'inode_cache' option is deprecated and has no effect since 5.11");
899 case Opt_clear_cache:
900 btrfs_set_and_info(info, CLEAR_CACHE,
901 "force clearing of disk cache");
903 case Opt_user_subvol_rm_allowed:
904 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
906 case Opt_enospc_debug:
907 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
909 case Opt_noenospc_debug:
910 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
913 btrfs_set_and_info(info, AUTO_DEFRAG,
914 "enabling auto defrag");
917 btrfs_clear_and_info(info, AUTO_DEFRAG,
918 "disabling auto defrag");
921 case Opt_usebackuproot:
923 "'%s' is deprecated, use 'rescue=usebackuproot' instead",
924 token == Opt_recovery ? "recovery" :
927 "trying to use backup root at mount time");
928 btrfs_set_opt(info->mount_opt, USEBACKUPROOT);
930 case Opt_skip_balance:
931 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
933 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
934 case Opt_check_integrity_including_extent_data:
936 "enabling check integrity including extent data");
937 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY_DATA);
938 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
940 case Opt_check_integrity:
941 btrfs_info(info, "enabling check integrity");
942 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
944 case Opt_check_integrity_print_mask:
945 ret = match_int(&args[0], &intarg);
948 info->check_integrity_print_mask = intarg;
949 btrfs_info(info, "check_integrity_print_mask 0x%x",
950 info->check_integrity_print_mask);
953 case Opt_check_integrity_including_extent_data:
954 case Opt_check_integrity:
955 case Opt_check_integrity_print_mask:
957 "support for check_integrity* not compiled in!");
961 case Opt_fatal_errors:
962 if (strcmp(args[0].from, "panic") == 0)
963 btrfs_set_opt(info->mount_opt,
964 PANIC_ON_FATAL_ERROR);
965 else if (strcmp(args[0].from, "bug") == 0)
966 btrfs_clear_opt(info->mount_opt,
967 PANIC_ON_FATAL_ERROR);
973 case Opt_commit_interval:
975 ret = match_int(&args[0], &intarg);
980 "using default commit interval %us",
981 BTRFS_DEFAULT_COMMIT_INTERVAL);
982 intarg = BTRFS_DEFAULT_COMMIT_INTERVAL;
983 } else if (intarg > 300) {
984 btrfs_warn(info, "excessive commit interval %d",
987 info->commit_interval = intarg;
990 ret = parse_rescue_options(info, args[0].from);
994 #ifdef CONFIG_BTRFS_DEBUG
995 case Opt_fragment_all:
996 btrfs_info(info, "fragmenting all space");
997 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
998 btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA);
1000 case Opt_fragment_metadata:
1001 btrfs_info(info, "fragmenting metadata");
1002 btrfs_set_opt(info->mount_opt,
1005 case Opt_fragment_data:
1006 btrfs_info(info, "fragmenting data");
1007 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
1010 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
1011 case Opt_ref_verify:
1012 btrfs_info(info, "doing ref verification");
1013 btrfs_set_opt(info->mount_opt, REF_VERIFY);
1017 btrfs_err(info, "unrecognized mount option '%s'", p);
1025 /* We're read-only, don't have to check. */
1026 if (new_flags & SB_RDONLY)
1029 if (check_ro_option(info, BTRFS_MOUNT_NOLOGREPLAY, "nologreplay") ||
1030 check_ro_option(info, BTRFS_MOUNT_IGNOREBADROOTS, "ignorebadroots") ||
1031 check_ro_option(info, BTRFS_MOUNT_IGNOREDATACSUMS, "ignoredatacsums"))
1034 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) &&
1035 !btrfs_test_opt(info, FREE_SPACE_TREE) &&
1036 !btrfs_test_opt(info, CLEAR_CACHE)) {
1037 btrfs_err(info, "cannot disable free space tree");
1042 ret = btrfs_check_mountopts_zoned(info);
1043 if (!ret && btrfs_test_opt(info, SPACE_CACHE))
1044 btrfs_info(info, "disk space caching is enabled");
1045 if (!ret && btrfs_test_opt(info, FREE_SPACE_TREE))
1046 btrfs_info(info, "using free space tree");
1051 * Parse mount options that are required early in the mount process.
1053 * All other options will be parsed on much later in the mount process and
1054 * only when we need to allocate a new super block.
1056 static int btrfs_parse_device_options(const char *options, fmode_t flags,
1059 substring_t args[MAX_OPT_ARGS];
1060 char *device_name, *opts, *orig, *p;
1061 struct btrfs_device *device = NULL;
1064 lockdep_assert_held(&uuid_mutex);
1070 * strsep changes the string, duplicate it because btrfs_parse_options
1073 opts = kstrdup(options, GFP_KERNEL);
1078 while ((p = strsep(&opts, ",")) != NULL) {
1084 token = match_token(p, tokens, args);
1085 if (token == Opt_device) {
1086 device_name = match_strdup(&args[0]);
1091 device = btrfs_scan_one_device(device_name, flags,
1094 if (IS_ERR(device)) {
1095 error = PTR_ERR(device);
1107 * Parse mount options that are related to subvolume id
1109 * The value is later passed to mount_subvol()
1111 static int btrfs_parse_subvol_options(const char *options, char **subvol_name,
1112 u64 *subvol_objectid)
1114 substring_t args[MAX_OPT_ARGS];
1115 char *opts, *orig, *p;
1123 * strsep changes the string, duplicate it because
1124 * btrfs_parse_device_options gets called later
1126 opts = kstrdup(options, GFP_KERNEL);
1131 while ((p = strsep(&opts, ",")) != NULL) {
1136 token = match_token(p, tokens, args);
1139 kfree(*subvol_name);
1140 *subvol_name = match_strdup(&args[0]);
1141 if (!*subvol_name) {
1147 error = match_u64(&args[0], &subvolid);
1151 /* we want the original fs_tree */
1153 subvolid = BTRFS_FS_TREE_OBJECTID;
1155 *subvol_objectid = subvolid;
1167 char *btrfs_get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
1168 u64 subvol_objectid)
1170 struct btrfs_root *root = fs_info->tree_root;
1171 struct btrfs_root *fs_root = NULL;
1172 struct btrfs_root_ref *root_ref;
1173 struct btrfs_inode_ref *inode_ref;
1174 struct btrfs_key key;
1175 struct btrfs_path *path = NULL;
1176 char *name = NULL, *ptr;
1181 path = btrfs_alloc_path();
1187 name = kmalloc(PATH_MAX, GFP_KERNEL);
1192 ptr = name + PATH_MAX - 1;
1196 * Walk up the subvolume trees in the tree of tree roots by root
1197 * backrefs until we hit the top-level subvolume.
1199 while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) {
1200 key.objectid = subvol_objectid;
1201 key.type = BTRFS_ROOT_BACKREF_KEY;
1202 key.offset = (u64)-1;
1204 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1207 } else if (ret > 0) {
1208 ret = btrfs_previous_item(root, path, subvol_objectid,
1209 BTRFS_ROOT_BACKREF_KEY);
1212 } else if (ret > 0) {
1218 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1219 subvol_objectid = key.offset;
1221 root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1222 struct btrfs_root_ref);
1223 len = btrfs_root_ref_name_len(path->nodes[0], root_ref);
1226 ret = -ENAMETOOLONG;
1229 read_extent_buffer(path->nodes[0], ptr + 1,
1230 (unsigned long)(root_ref + 1), len);
1232 dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref);
1233 btrfs_release_path(path);
1235 fs_root = btrfs_get_fs_root(fs_info, subvol_objectid, true);
1236 if (IS_ERR(fs_root)) {
1237 ret = PTR_ERR(fs_root);
1243 * Walk up the filesystem tree by inode refs until we hit the
1246 while (dirid != BTRFS_FIRST_FREE_OBJECTID) {
1247 key.objectid = dirid;
1248 key.type = BTRFS_INODE_REF_KEY;
1249 key.offset = (u64)-1;
1251 ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0);
1254 } else if (ret > 0) {
1255 ret = btrfs_previous_item(fs_root, path, dirid,
1256 BTRFS_INODE_REF_KEY);
1259 } else if (ret > 0) {
1265 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1268 inode_ref = btrfs_item_ptr(path->nodes[0],
1270 struct btrfs_inode_ref);
1271 len = btrfs_inode_ref_name_len(path->nodes[0],
1275 ret = -ENAMETOOLONG;
1278 read_extent_buffer(path->nodes[0], ptr + 1,
1279 (unsigned long)(inode_ref + 1), len);
1281 btrfs_release_path(path);
1283 btrfs_put_root(fs_root);
1287 btrfs_free_path(path);
1288 if (ptr == name + PATH_MAX - 1) {
1292 memmove(name, ptr, name + PATH_MAX - ptr);
1297 btrfs_put_root(fs_root);
1298 btrfs_free_path(path);
1300 return ERR_PTR(ret);
1303 static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid)
1305 struct btrfs_root *root = fs_info->tree_root;
1306 struct btrfs_dir_item *di;
1307 struct btrfs_path *path;
1308 struct btrfs_key location;
1311 path = btrfs_alloc_path();
1316 * Find the "default" dir item which points to the root item that we
1317 * will mount by default if we haven't been given a specific subvolume
1320 dir_id = btrfs_super_root_dir(fs_info->super_copy);
1321 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
1323 btrfs_free_path(path);
1328 * Ok the default dir item isn't there. This is weird since
1329 * it's always been there, but don't freak out, just try and
1330 * mount the top-level subvolume.
1332 btrfs_free_path(path);
1333 *objectid = BTRFS_FS_TREE_OBJECTID;
1337 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
1338 btrfs_free_path(path);
1339 *objectid = location.objectid;
1343 static int btrfs_fill_super(struct super_block *sb,
1344 struct btrfs_fs_devices *fs_devices,
1347 struct inode *inode;
1348 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1351 sb->s_maxbytes = MAX_LFS_FILESIZE;
1352 sb->s_magic = BTRFS_SUPER_MAGIC;
1353 sb->s_op = &btrfs_super_ops;
1354 sb->s_d_op = &btrfs_dentry_operations;
1355 sb->s_export_op = &btrfs_export_ops;
1356 sb->s_xattr = btrfs_xattr_handlers;
1357 sb->s_time_gran = 1;
1358 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
1359 sb->s_flags |= SB_POSIXACL;
1361 sb->s_flags |= SB_I_VERSION;
1362 sb->s_iflags |= SB_I_CGROUPWB;
1364 err = super_setup_bdi(sb);
1366 btrfs_err(fs_info, "super_setup_bdi failed");
1370 err = open_ctree(sb, fs_devices, (char *)data);
1372 btrfs_err(fs_info, "open_ctree failed");
1376 inode = btrfs_iget(sb, BTRFS_FIRST_FREE_OBJECTID, fs_info->fs_root);
1377 if (IS_ERR(inode)) {
1378 err = PTR_ERR(inode);
1382 sb->s_root = d_make_root(inode);
1388 cleancache_init_fs(sb);
1389 sb->s_flags |= SB_ACTIVE;
1393 close_ctree(fs_info);
1397 int btrfs_sync_fs(struct super_block *sb, int wait)
1399 struct btrfs_trans_handle *trans;
1400 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1401 struct btrfs_root *root = fs_info->tree_root;
1403 trace_btrfs_sync_fs(fs_info, wait);
1406 filemap_flush(fs_info->btree_inode->i_mapping);
1410 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
1412 trans = btrfs_attach_transaction_barrier(root);
1413 if (IS_ERR(trans)) {
1414 /* no transaction, don't bother */
1415 if (PTR_ERR(trans) == -ENOENT) {
1417 * Exit unless we have some pending changes
1418 * that need to go through commit
1420 if (fs_info->pending_changes == 0)
1423 * A non-blocking test if the fs is frozen. We must not
1424 * start a new transaction here otherwise a deadlock
1425 * happens. The pending operations are delayed to the
1426 * next commit after thawing.
1428 if (sb_start_write_trylock(sb))
1432 trans = btrfs_start_transaction(root, 0);
1435 return PTR_ERR(trans);
1437 return btrfs_commit_transaction(trans);
1440 static void print_rescue_option(struct seq_file *seq, const char *s, bool *printed)
1442 seq_printf(seq, "%s%s", (*printed) ? ":" : ",rescue=", s);
1446 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
1448 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
1449 const char *compress_type;
1450 const char *subvol_name;
1451 bool printed = false;
1453 if (btrfs_test_opt(info, DEGRADED))
1454 seq_puts(seq, ",degraded");
1455 if (btrfs_test_opt(info, NODATASUM))
1456 seq_puts(seq, ",nodatasum");
1457 if (btrfs_test_opt(info, NODATACOW))
1458 seq_puts(seq, ",nodatacow");
1459 if (btrfs_test_opt(info, NOBARRIER))
1460 seq_puts(seq, ",nobarrier");
1461 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE)
1462 seq_printf(seq, ",max_inline=%llu", info->max_inline);
1463 if (info->thread_pool_size != min_t(unsigned long,
1464 num_online_cpus() + 2, 8))
1465 seq_printf(seq, ",thread_pool=%u", info->thread_pool_size);
1466 if (btrfs_test_opt(info, COMPRESS)) {
1467 compress_type = btrfs_compress_type2str(info->compress_type);
1468 if (btrfs_test_opt(info, FORCE_COMPRESS))
1469 seq_printf(seq, ",compress-force=%s", compress_type);
1471 seq_printf(seq, ",compress=%s", compress_type);
1472 if (info->compress_level)
1473 seq_printf(seq, ":%d", info->compress_level);
1475 if (btrfs_test_opt(info, NOSSD))
1476 seq_puts(seq, ",nossd");
1477 if (btrfs_test_opt(info, SSD_SPREAD))
1478 seq_puts(seq, ",ssd_spread");
1479 else if (btrfs_test_opt(info, SSD))
1480 seq_puts(seq, ",ssd");
1481 if (btrfs_test_opt(info, NOTREELOG))
1482 seq_puts(seq, ",notreelog");
1483 if (btrfs_test_opt(info, NOLOGREPLAY))
1484 print_rescue_option(seq, "nologreplay", &printed);
1485 if (btrfs_test_opt(info, USEBACKUPROOT))
1486 print_rescue_option(seq, "usebackuproot", &printed);
1487 if (btrfs_test_opt(info, IGNOREBADROOTS))
1488 print_rescue_option(seq, "ignorebadroots", &printed);
1489 if (btrfs_test_opt(info, IGNOREDATACSUMS))
1490 print_rescue_option(seq, "ignoredatacsums", &printed);
1491 if (btrfs_test_opt(info, FLUSHONCOMMIT))
1492 seq_puts(seq, ",flushoncommit");
1493 if (btrfs_test_opt(info, DISCARD_SYNC))
1494 seq_puts(seq, ",discard");
1495 if (btrfs_test_opt(info, DISCARD_ASYNC))
1496 seq_puts(seq, ",discard=async");
1497 if (!(info->sb->s_flags & SB_POSIXACL))
1498 seq_puts(seq, ",noacl");
1499 if (btrfs_free_space_cache_v1_active(info))
1500 seq_puts(seq, ",space_cache");
1501 else if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
1502 seq_puts(seq, ",space_cache=v2");
1504 seq_puts(seq, ",nospace_cache");
1505 if (btrfs_test_opt(info, RESCAN_UUID_TREE))
1506 seq_puts(seq, ",rescan_uuid_tree");
1507 if (btrfs_test_opt(info, CLEAR_CACHE))
1508 seq_puts(seq, ",clear_cache");
1509 if (btrfs_test_opt(info, USER_SUBVOL_RM_ALLOWED))
1510 seq_puts(seq, ",user_subvol_rm_allowed");
1511 if (btrfs_test_opt(info, ENOSPC_DEBUG))
1512 seq_puts(seq, ",enospc_debug");
1513 if (btrfs_test_opt(info, AUTO_DEFRAG))
1514 seq_puts(seq, ",autodefrag");
1515 if (btrfs_test_opt(info, SKIP_BALANCE))
1516 seq_puts(seq, ",skip_balance");
1517 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1518 if (btrfs_test_opt(info, CHECK_INTEGRITY_DATA))
1519 seq_puts(seq, ",check_int_data");
1520 else if (btrfs_test_opt(info, CHECK_INTEGRITY))
1521 seq_puts(seq, ",check_int");
1522 if (info->check_integrity_print_mask)
1523 seq_printf(seq, ",check_int_print_mask=%d",
1524 info->check_integrity_print_mask);
1526 if (info->metadata_ratio)
1527 seq_printf(seq, ",metadata_ratio=%u", info->metadata_ratio);
1528 if (btrfs_test_opt(info, PANIC_ON_FATAL_ERROR))
1529 seq_puts(seq, ",fatal_errors=panic");
1530 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1531 seq_printf(seq, ",commit=%u", info->commit_interval);
1532 #ifdef CONFIG_BTRFS_DEBUG
1533 if (btrfs_test_opt(info, FRAGMENT_DATA))
1534 seq_puts(seq, ",fragment=data");
1535 if (btrfs_test_opt(info, FRAGMENT_METADATA))
1536 seq_puts(seq, ",fragment=metadata");
1538 if (btrfs_test_opt(info, REF_VERIFY))
1539 seq_puts(seq, ",ref_verify");
1540 seq_printf(seq, ",subvolid=%llu",
1541 BTRFS_I(d_inode(dentry))->root->root_key.objectid);
1542 subvol_name = btrfs_get_subvol_name_from_objectid(info,
1543 BTRFS_I(d_inode(dentry))->root->root_key.objectid);
1544 if (!IS_ERR(subvol_name)) {
1545 seq_puts(seq, ",subvol=");
1546 seq_escape(seq, subvol_name, " \t\n\\");
1552 static int btrfs_test_super(struct super_block *s, void *data)
1554 struct btrfs_fs_info *p = data;
1555 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1557 return fs_info->fs_devices == p->fs_devices;
1560 static int btrfs_set_super(struct super_block *s, void *data)
1562 int err = set_anon_super(s, data);
1564 s->s_fs_info = data;
1569 * subvolumes are identified by ino 256
1571 static inline int is_subvolume_inode(struct inode *inode)
1573 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1578 static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid,
1579 struct vfsmount *mnt)
1581 struct dentry *root;
1585 if (!subvol_objectid) {
1586 ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb),
1589 root = ERR_PTR(ret);
1593 subvol_name = btrfs_get_subvol_name_from_objectid(
1594 btrfs_sb(mnt->mnt_sb), subvol_objectid);
1595 if (IS_ERR(subvol_name)) {
1596 root = ERR_CAST(subvol_name);
1603 root = mount_subtree(mnt, subvol_name);
1604 /* mount_subtree() drops our reference on the vfsmount. */
1607 if (!IS_ERR(root)) {
1608 struct super_block *s = root->d_sb;
1609 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1610 struct inode *root_inode = d_inode(root);
1611 u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid;
1614 if (!is_subvolume_inode(root_inode)) {
1615 btrfs_err(fs_info, "'%s' is not a valid subvolume",
1619 if (subvol_objectid && root_objectid != subvol_objectid) {
1621 * This will also catch a race condition where a
1622 * subvolume which was passed by ID is renamed and
1623 * another subvolume is renamed over the old location.
1626 "subvol '%s' does not match subvolid %llu",
1627 subvol_name, subvol_objectid);
1632 root = ERR_PTR(ret);
1633 deactivate_locked_super(s);
1644 * Find a superblock for the given device / mount point.
1646 * Note: This is based on mount_bdev from fs/super.c with a few additions
1647 * for multiple device setup. Make sure to keep it in sync.
1649 static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
1650 int flags, const char *device_name, void *data)
1652 struct block_device *bdev = NULL;
1653 struct super_block *s;
1654 struct btrfs_device *device = NULL;
1655 struct btrfs_fs_devices *fs_devices = NULL;
1656 struct btrfs_fs_info *fs_info = NULL;
1657 void *new_sec_opts = NULL;
1658 fmode_t mode = FMODE_READ;
1661 if (!(flags & SB_RDONLY))
1662 mode |= FMODE_WRITE;
1665 error = security_sb_eat_lsm_opts(data, &new_sec_opts);
1667 return ERR_PTR(error);
1671 * Setup a dummy root and fs_info for test/set super. This is because
1672 * we don't actually fill this stuff out until open_ctree, but we need
1673 * then open_ctree will properly initialize the file system specific
1674 * settings later. btrfs_init_fs_info initializes the static elements
1675 * of the fs_info (locks and such) to make cleanup easier if we find a
1676 * superblock with our given fs_devices later on at sget() time.
1678 fs_info = kvzalloc(sizeof(struct btrfs_fs_info), GFP_KERNEL);
1681 goto error_sec_opts;
1683 btrfs_init_fs_info(fs_info);
1685 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1686 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1687 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1692 mutex_lock(&uuid_mutex);
1693 error = btrfs_parse_device_options(data, mode, fs_type);
1695 mutex_unlock(&uuid_mutex);
1699 device = btrfs_scan_one_device(device_name, mode, fs_type);
1700 if (IS_ERR(device)) {
1701 mutex_unlock(&uuid_mutex);
1702 error = PTR_ERR(device);
1706 fs_devices = device->fs_devices;
1707 fs_info->fs_devices = fs_devices;
1709 error = btrfs_open_devices(fs_devices, mode, fs_type);
1710 mutex_unlock(&uuid_mutex);
1714 if (!(flags & SB_RDONLY) && fs_devices->rw_devices == 0) {
1716 goto error_close_devices;
1719 bdev = fs_devices->latest_bdev;
1720 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | SB_NOSEC,
1724 goto error_close_devices;
1728 btrfs_close_devices(fs_devices);
1729 btrfs_free_fs_info(fs_info);
1730 if ((flags ^ s->s_flags) & SB_RDONLY)
1733 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
1734 btrfs_sb(s)->bdev_holder = fs_type;
1735 if (!strstr(crc32c_impl(), "generic"))
1736 set_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags);
1737 error = btrfs_fill_super(s, fs_devices, data);
1740 error = security_sb_set_mnt_opts(s, new_sec_opts, 0, NULL);
1741 security_free_mnt_opts(&new_sec_opts);
1743 deactivate_locked_super(s);
1744 return ERR_PTR(error);
1747 return dget(s->s_root);
1749 error_close_devices:
1750 btrfs_close_devices(fs_devices);
1752 btrfs_free_fs_info(fs_info);
1754 security_free_mnt_opts(&new_sec_opts);
1755 return ERR_PTR(error);
1759 * Mount function which is called by VFS layer.
1761 * In order to allow mounting a subvolume directly, btrfs uses mount_subtree()
1762 * which needs vfsmount* of device's root (/). This means device's root has to
1763 * be mounted internally in any case.
1766 * 1. Parse subvol id related options for later use in mount_subvol().
1768 * 2. Mount device's root (/) by calling vfs_kern_mount().
1770 * NOTE: vfs_kern_mount() is used by VFS to call btrfs_mount() in the
1771 * first place. In order to avoid calling btrfs_mount() again, we use
1772 * different file_system_type which is not registered to VFS by
1773 * register_filesystem() (btrfs_root_fs_type). As a result,
1774 * btrfs_mount_root() is called. The return value will be used by
1775 * mount_subtree() in mount_subvol().
1777 * 3. Call mount_subvol() to get the dentry of subvolume. Since there is
1778 * "btrfs subvolume set-default", mount_subvol() is called always.
1780 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1781 const char *device_name, void *data)
1783 struct vfsmount *mnt_root;
1784 struct dentry *root;
1785 char *subvol_name = NULL;
1786 u64 subvol_objectid = 0;
1789 error = btrfs_parse_subvol_options(data, &subvol_name,
1793 return ERR_PTR(error);
1796 /* mount device's root (/) */
1797 mnt_root = vfs_kern_mount(&btrfs_root_fs_type, flags, device_name, data);
1798 if (PTR_ERR_OR_ZERO(mnt_root) == -EBUSY) {
1799 if (flags & SB_RDONLY) {
1800 mnt_root = vfs_kern_mount(&btrfs_root_fs_type,
1801 flags & ~SB_RDONLY, device_name, data);
1803 mnt_root = vfs_kern_mount(&btrfs_root_fs_type,
1804 flags | SB_RDONLY, device_name, data);
1805 if (IS_ERR(mnt_root)) {
1806 root = ERR_CAST(mnt_root);
1811 down_write(&mnt_root->mnt_sb->s_umount);
1812 error = btrfs_remount(mnt_root->mnt_sb, &flags, NULL);
1813 up_write(&mnt_root->mnt_sb->s_umount);
1815 root = ERR_PTR(error);
1822 if (IS_ERR(mnt_root)) {
1823 root = ERR_CAST(mnt_root);
1828 /* mount_subvol() will free subvol_name and mnt_root */
1829 root = mount_subvol(subvol_name, subvol_objectid, mnt_root);
1835 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1836 u32 new_pool_size, u32 old_pool_size)
1838 if (new_pool_size == old_pool_size)
1841 fs_info->thread_pool_size = new_pool_size;
1843 btrfs_info(fs_info, "resize thread pool %d -> %d",
1844 old_pool_size, new_pool_size);
1846 btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
1847 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
1848 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
1849 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
1850 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
1851 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
1853 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
1854 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
1855 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
1856 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size);
1857 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers,
1861 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1862 unsigned long old_opts, int flags)
1864 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1865 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1866 (flags & SB_RDONLY))) {
1867 /* wait for any defraggers to finish */
1868 wait_event(fs_info->transaction_wait,
1869 (atomic_read(&fs_info->defrag_running) == 0));
1870 if (flags & SB_RDONLY)
1871 sync_filesystem(fs_info->sb);
1875 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1876 unsigned long old_opts)
1878 const bool cache_opt = btrfs_test_opt(fs_info, SPACE_CACHE);
1881 * We need to cleanup all defragable inodes if the autodefragment is
1882 * close or the filesystem is read only.
1884 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1885 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || sb_rdonly(fs_info->sb))) {
1886 btrfs_cleanup_defrag_inodes(fs_info);
1889 /* If we toggled discard async */
1890 if (!btrfs_raw_test_opt(old_opts, DISCARD_ASYNC) &&
1891 btrfs_test_opt(fs_info, DISCARD_ASYNC))
1892 btrfs_discard_resume(fs_info);
1893 else if (btrfs_raw_test_opt(old_opts, DISCARD_ASYNC) &&
1894 !btrfs_test_opt(fs_info, DISCARD_ASYNC))
1895 btrfs_discard_cleanup(fs_info);
1897 /* If we toggled space cache */
1898 if (cache_opt != btrfs_free_space_cache_v1_active(fs_info))
1899 btrfs_set_free_space_cache_v1_active(fs_info, cache_opt);
1902 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1904 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1905 unsigned old_flags = sb->s_flags;
1906 unsigned long old_opts = fs_info->mount_opt;
1907 unsigned long old_compress_type = fs_info->compress_type;
1908 u64 old_max_inline = fs_info->max_inline;
1909 u32 old_thread_pool_size = fs_info->thread_pool_size;
1910 u32 old_metadata_ratio = fs_info->metadata_ratio;
1913 sync_filesystem(sb);
1914 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1917 void *new_sec_opts = NULL;
1919 ret = security_sb_eat_lsm_opts(data, &new_sec_opts);
1921 ret = security_sb_remount(sb, new_sec_opts);
1922 security_free_mnt_opts(&new_sec_opts);
1927 ret = btrfs_parse_options(fs_info, data, *flags);
1931 btrfs_remount_begin(fs_info, old_opts, *flags);
1932 btrfs_resize_thread_pool(fs_info,
1933 fs_info->thread_pool_size, old_thread_pool_size);
1935 if ((bool)btrfs_test_opt(fs_info, FREE_SPACE_TREE) !=
1936 (bool)btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
1937 (!sb_rdonly(sb) || (*flags & SB_RDONLY))) {
1939 "remount supports changing free space tree only from ro to rw");
1940 /* Make sure free space cache options match the state on disk */
1941 if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
1942 btrfs_set_opt(fs_info->mount_opt, FREE_SPACE_TREE);
1943 btrfs_clear_opt(fs_info->mount_opt, SPACE_CACHE);
1945 if (btrfs_free_space_cache_v1_active(fs_info)) {
1946 btrfs_clear_opt(fs_info->mount_opt, FREE_SPACE_TREE);
1947 btrfs_set_opt(fs_info->mount_opt, SPACE_CACHE);
1951 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1954 if (*flags & SB_RDONLY) {
1956 * this also happens on 'umount -rf' or on shutdown, when
1957 * the filesystem is busy.
1959 cancel_work_sync(&fs_info->async_reclaim_work);
1960 cancel_work_sync(&fs_info->async_data_reclaim_work);
1962 btrfs_discard_cleanup(fs_info);
1964 /* wait for the uuid_scan task to finish */
1965 down(&fs_info->uuid_tree_rescan_sem);
1966 /* avoid complains from lockdep et al. */
1967 up(&fs_info->uuid_tree_rescan_sem);
1969 btrfs_set_sb_rdonly(sb);
1972 * Setting SB_RDONLY will put the cleaner thread to
1973 * sleep at the next loop if it's already active.
1974 * If it's already asleep, we'll leave unused block
1975 * groups on disk until we're mounted read-write again
1976 * unless we clean them up here.
1978 btrfs_delete_unused_bgs(fs_info);
1981 * The cleaner task could be already running before we set the
1982 * flag BTRFS_FS_STATE_RO (and SB_RDONLY in the superblock).
1983 * We must make sure that after we finish the remount, i.e. after
1984 * we call btrfs_commit_super(), the cleaner can no longer start
1985 * a transaction - either because it was dropping a dead root,
1986 * running delayed iputs or deleting an unused block group (the
1987 * cleaner picked a block group from the list of unused block
1988 * groups before we were able to in the previous call to
1989 * btrfs_delete_unused_bgs()).
1991 wait_on_bit(&fs_info->flags, BTRFS_FS_CLEANER_RUNNING,
1992 TASK_UNINTERRUPTIBLE);
1995 * We've set the superblock to RO mode, so we might have made
1996 * the cleaner task sleep without running all pending delayed
1997 * iputs. Go through all the delayed iputs here, so that if an
1998 * unmount happens without remounting RW we don't end up at
1999 * finishing close_ctree() with a non-empty list of delayed
2002 btrfs_run_delayed_iputs(fs_info);
2004 btrfs_dev_replace_suspend_for_unmount(fs_info);
2005 btrfs_scrub_cancel(fs_info);
2006 btrfs_pause_balance(fs_info);
2009 * Pause the qgroup rescan worker if it is running. We don't want
2010 * it to be still running after we are in RO mode, as after that,
2011 * by the time we unmount, it might have left a transaction open,
2012 * so we would leak the transaction and/or crash.
2014 btrfs_qgroup_wait_for_completion(fs_info, false);
2016 ret = btrfs_commit_super(fs_info);
2020 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
2022 "Remounting read-write after error is not allowed");
2026 if (fs_info->fs_devices->rw_devices == 0) {
2031 if (!btrfs_check_rw_degradable(fs_info, NULL)) {
2033 "too many missing devices, writable remount is not allowed");
2038 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
2040 "mount required to replay tree-log, cannot remount read-write");
2044 if (fs_info->sectorsize < PAGE_SIZE) {
2046 "read-write mount is not yet allowed for sectorsize %u page size %lu",
2047 fs_info->sectorsize, PAGE_SIZE);
2053 * NOTE: when remounting with a change that does writes, don't
2054 * put it anywhere above this point, as we are not sure to be
2055 * safe to write until we pass the above checks.
2057 ret = btrfs_start_pre_rw_mount(fs_info);
2061 btrfs_clear_sb_rdonly(sb);
2063 set_bit(BTRFS_FS_OPEN, &fs_info->flags);
2067 * We need to set SB_I_VERSION here otherwise it'll get cleared by VFS,
2068 * since the absence of the flag means it can be toggled off by remount.
2070 *flags |= SB_I_VERSION;
2072 wake_up_process(fs_info->transaction_kthread);
2073 btrfs_remount_cleanup(fs_info, old_opts);
2074 btrfs_clear_oneshot_options(fs_info);
2075 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
2080 /* We've hit an error - don't reset SB_RDONLY */
2082 old_flags |= SB_RDONLY;
2083 if (!(old_flags & SB_RDONLY))
2084 clear_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state);
2085 sb->s_flags = old_flags;
2086 fs_info->mount_opt = old_opts;
2087 fs_info->compress_type = old_compress_type;
2088 fs_info->max_inline = old_max_inline;
2089 btrfs_resize_thread_pool(fs_info,
2090 old_thread_pool_size, fs_info->thread_pool_size);
2091 fs_info->metadata_ratio = old_metadata_ratio;
2092 btrfs_remount_cleanup(fs_info, old_opts);
2093 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
2098 /* Used to sort the devices by max_avail(descending sort) */
2099 static inline int btrfs_cmp_device_free_bytes(const void *dev_info1,
2100 const void *dev_info2)
2102 if (((struct btrfs_device_info *)dev_info1)->max_avail >
2103 ((struct btrfs_device_info *)dev_info2)->max_avail)
2105 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
2106 ((struct btrfs_device_info *)dev_info2)->max_avail)
2113 * sort the devices by max_avail, in which max free extent size of each device
2114 * is stored.(Descending Sort)
2116 static inline void btrfs_descending_sort_devices(
2117 struct btrfs_device_info *devices,
2120 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
2121 btrfs_cmp_device_free_bytes, NULL);
2125 * The helper to calc the free space on the devices that can be used to store
2128 static inline int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
2131 struct btrfs_device_info *devices_info;
2132 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2133 struct btrfs_device *device;
2136 u64 min_stripe_size;
2137 int num_stripes = 1;
2138 int i = 0, nr_devices;
2139 const struct btrfs_raid_attr *rattr;
2142 * We aren't under the device list lock, so this is racy-ish, but good
2143 * enough for our purposes.
2145 nr_devices = fs_info->fs_devices->open_devices;
2148 nr_devices = fs_info->fs_devices->open_devices;
2156 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
2161 /* calc min stripe number for data space allocation */
2162 type = btrfs_data_alloc_profile(fs_info);
2163 rattr = &btrfs_raid_array[btrfs_bg_flags_to_raid_index(type)];
2165 if (type & BTRFS_BLOCK_GROUP_RAID0)
2166 num_stripes = nr_devices;
2167 else if (type & BTRFS_BLOCK_GROUP_RAID1)
2169 else if (type & BTRFS_BLOCK_GROUP_RAID1C3)
2171 else if (type & BTRFS_BLOCK_GROUP_RAID1C4)
2173 else if (type & BTRFS_BLOCK_GROUP_RAID10)
2176 /* Adjust for more than 1 stripe per device */
2177 min_stripe_size = rattr->dev_stripes * BTRFS_STRIPE_LEN;
2180 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
2181 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
2182 &device->dev_state) ||
2184 test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
2187 if (i >= nr_devices)
2190 avail_space = device->total_bytes - device->bytes_used;
2192 /* align with stripe_len */
2193 avail_space = rounddown(avail_space, BTRFS_STRIPE_LEN);
2196 * In order to avoid overwriting the superblock on the drive,
2197 * btrfs starts at an offset of at least 1MB when doing chunk
2200 * This ensures we have at least min_stripe_size free space
2201 * after excluding 1MB.
2203 if (avail_space <= SZ_1M + min_stripe_size)
2206 avail_space -= SZ_1M;
2208 devices_info[i].dev = device;
2209 devices_info[i].max_avail = avail_space;
2217 btrfs_descending_sort_devices(devices_info, nr_devices);
2221 while (nr_devices >= rattr->devs_min) {
2222 num_stripes = min(num_stripes, nr_devices);
2224 if (devices_info[i].max_avail >= min_stripe_size) {
2228 avail_space += devices_info[i].max_avail * num_stripes;
2229 alloc_size = devices_info[i].max_avail;
2230 for (j = i + 1 - num_stripes; j <= i; j++)
2231 devices_info[j].max_avail -= alloc_size;
2237 kfree(devices_info);
2238 *free_bytes = avail_space;
2243 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles.
2245 * If there's a redundant raid level at DATA block groups, use the respective
2246 * multiplier to scale the sizes.
2248 * Unused device space usage is based on simulating the chunk allocator
2249 * algorithm that respects the device sizes and order of allocations. This is
2250 * a close approximation of the actual use but there are other factors that may
2251 * change the result (like a new metadata chunk).
2253 * If metadata is exhausted, f_bavail will be 0.
2255 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
2257 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
2258 struct btrfs_super_block *disk_super = fs_info->super_copy;
2259 struct btrfs_space_info *found;
2261 u64 total_free_data = 0;
2262 u64 total_free_meta = 0;
2263 u32 bits = fs_info->sectorsize_bits;
2264 __be32 *fsid = (__be32 *)fs_info->fs_devices->fsid;
2265 unsigned factor = 1;
2266 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
2271 list_for_each_entry(found, &fs_info->space_info, list) {
2272 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
2275 total_free_data += found->disk_total - found->disk_used;
2277 btrfs_account_ro_block_groups_free_space(found);
2279 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
2280 if (!list_empty(&found->block_groups[i]))
2281 factor = btrfs_bg_type_to_factor(
2282 btrfs_raid_array[i].bg_flag);
2287 * Metadata in mixed block goup profiles are accounted in data
2289 if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) {
2290 if (found->flags & BTRFS_BLOCK_GROUP_DATA)
2293 total_free_meta += found->disk_total -
2297 total_used += found->disk_used;
2300 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor);
2301 buf->f_blocks >>= bits;
2302 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits);
2304 /* Account global block reserve as used, it's in logical size already */
2305 spin_lock(&block_rsv->lock);
2306 /* Mixed block groups accounting is not byte-accurate, avoid overflow */
2307 if (buf->f_bfree >= block_rsv->size >> bits)
2308 buf->f_bfree -= block_rsv->size >> bits;
2311 spin_unlock(&block_rsv->lock);
2313 buf->f_bavail = div_u64(total_free_data, factor);
2314 ret = btrfs_calc_avail_data_space(fs_info, &total_free_data);
2317 buf->f_bavail += div_u64(total_free_data, factor);
2318 buf->f_bavail = buf->f_bavail >> bits;
2321 * We calculate the remaining metadata space minus global reserve. If
2322 * this is (supposedly) smaller than zero, there's no space. But this
2323 * does not hold in practice, the exhausted state happens where's still
2324 * some positive delta. So we apply some guesswork and compare the
2325 * delta to a 4M threshold. (Practically observed delta was ~2M.)
2327 * We probably cannot calculate the exact threshold value because this
2328 * depends on the internal reservations requested by various
2329 * operations, so some operations that consume a few metadata will
2330 * succeed even if the Avail is zero. But this is better than the other
2336 * We only want to claim there's no available space if we can no longer
2337 * allocate chunks for our metadata profile and our global reserve will
2338 * not fit in the free metadata space. If we aren't ->full then we
2339 * still can allocate chunks and thus are fine using the currently
2340 * calculated f_bavail.
2342 if (!mixed && block_rsv->space_info->full &&
2343 total_free_meta - thresh < block_rsv->size)
2346 buf->f_type = BTRFS_SUPER_MAGIC;
2347 buf->f_bsize = dentry->d_sb->s_blocksize;
2348 buf->f_namelen = BTRFS_NAME_LEN;
2350 /* We treat it as constant endianness (it doesn't matter _which_)
2351 because we want the fsid to come out the same whether mounted
2352 on a big-endian or little-endian host */
2353 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
2354 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
2355 /* Mask in the root object ID too, to disambiguate subvols */
2356 buf->f_fsid.val[0] ^=
2357 BTRFS_I(d_inode(dentry))->root->root_key.objectid >> 32;
2358 buf->f_fsid.val[1] ^=
2359 BTRFS_I(d_inode(dentry))->root->root_key.objectid;
2364 static void btrfs_kill_super(struct super_block *sb)
2366 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2367 kill_anon_super(sb);
2368 btrfs_free_fs_info(fs_info);
2371 static struct file_system_type btrfs_fs_type = {
2372 .owner = THIS_MODULE,
2374 .mount = btrfs_mount,
2375 .kill_sb = btrfs_kill_super,
2376 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2379 static struct file_system_type btrfs_root_fs_type = {
2380 .owner = THIS_MODULE,
2382 .mount = btrfs_mount_root,
2383 .kill_sb = btrfs_kill_super,
2384 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2387 MODULE_ALIAS_FS("btrfs");
2389 static int btrfs_control_open(struct inode *inode, struct file *file)
2392 * The control file's private_data is used to hold the
2393 * transaction when it is started and is used to keep
2394 * track of whether a transaction is already in progress.
2396 file->private_data = NULL;
2401 * Used by /dev/btrfs-control for devices ioctls.
2403 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
2406 struct btrfs_ioctl_vol_args *vol;
2407 struct btrfs_device *device = NULL;
2410 if (!capable(CAP_SYS_ADMIN))
2413 vol = memdup_user((void __user *)arg, sizeof(*vol));
2415 return PTR_ERR(vol);
2416 vol->name[BTRFS_PATH_NAME_MAX] = '\0';
2419 case BTRFS_IOC_SCAN_DEV:
2420 mutex_lock(&uuid_mutex);
2421 device = btrfs_scan_one_device(vol->name, FMODE_READ,
2422 &btrfs_root_fs_type);
2423 ret = PTR_ERR_OR_ZERO(device);
2424 mutex_unlock(&uuid_mutex);
2426 case BTRFS_IOC_FORGET_DEV:
2427 ret = btrfs_forget_devices(vol->name);
2429 case BTRFS_IOC_DEVICES_READY:
2430 mutex_lock(&uuid_mutex);
2431 device = btrfs_scan_one_device(vol->name, FMODE_READ,
2432 &btrfs_root_fs_type);
2433 if (IS_ERR(device)) {
2434 mutex_unlock(&uuid_mutex);
2435 ret = PTR_ERR(device);
2438 ret = !(device->fs_devices->num_devices ==
2439 device->fs_devices->total_devices);
2440 mutex_unlock(&uuid_mutex);
2442 case BTRFS_IOC_GET_SUPPORTED_FEATURES:
2443 ret = btrfs_ioctl_get_supported_features((void __user*)arg);
2451 static int btrfs_freeze(struct super_block *sb)
2453 struct btrfs_trans_handle *trans;
2454 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2455 struct btrfs_root *root = fs_info->tree_root;
2457 set_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2459 * We don't need a barrier here, we'll wait for any transaction that
2460 * could be in progress on other threads (and do delayed iputs that
2461 * we want to avoid on a frozen filesystem), or do the commit
2464 trans = btrfs_attach_transaction_barrier(root);
2465 if (IS_ERR(trans)) {
2466 /* no transaction, don't bother */
2467 if (PTR_ERR(trans) == -ENOENT)
2469 return PTR_ERR(trans);
2471 return btrfs_commit_transaction(trans);
2474 static int btrfs_unfreeze(struct super_block *sb)
2476 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2478 clear_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2482 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
2484 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
2485 struct btrfs_device *dev, *first_dev = NULL;
2488 * Lightweight locking of the devices. We should not need
2489 * device_list_mutex here as we only read the device data and the list
2490 * is protected by RCU. Even if a device is deleted during the list
2491 * traversals, we'll get valid data, the freeing callback will wait at
2492 * least until the rcu_read_unlock.
2495 list_for_each_entry_rcu(dev, &fs_info->fs_devices->devices, dev_list) {
2496 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
2500 if (!first_dev || dev->devid < first_dev->devid)
2505 seq_escape(m, rcu_str_deref(first_dev->name), " \t\n\\");
2512 static const struct super_operations btrfs_super_ops = {
2513 .drop_inode = btrfs_drop_inode,
2514 .evict_inode = btrfs_evict_inode,
2515 .put_super = btrfs_put_super,
2516 .sync_fs = btrfs_sync_fs,
2517 .show_options = btrfs_show_options,
2518 .show_devname = btrfs_show_devname,
2519 .alloc_inode = btrfs_alloc_inode,
2520 .destroy_inode = btrfs_destroy_inode,
2521 .free_inode = btrfs_free_inode,
2522 .statfs = btrfs_statfs,
2523 .remount_fs = btrfs_remount,
2524 .freeze_fs = btrfs_freeze,
2525 .unfreeze_fs = btrfs_unfreeze,
2528 static const struct file_operations btrfs_ctl_fops = {
2529 .open = btrfs_control_open,
2530 .unlocked_ioctl = btrfs_control_ioctl,
2531 .compat_ioctl = compat_ptr_ioctl,
2532 .owner = THIS_MODULE,
2533 .llseek = noop_llseek,
2536 static struct miscdevice btrfs_misc = {
2537 .minor = BTRFS_MINOR,
2538 .name = "btrfs-control",
2539 .fops = &btrfs_ctl_fops
2542 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
2543 MODULE_ALIAS("devname:btrfs-control");
2545 static int __init btrfs_interface_init(void)
2547 return misc_register(&btrfs_misc);
2550 static __cold void btrfs_interface_exit(void)
2552 misc_deregister(&btrfs_misc);
2555 static void __init btrfs_print_mod_info(void)
2557 static const char options[] = ""
2558 #ifdef CONFIG_BTRFS_DEBUG
2561 #ifdef CONFIG_BTRFS_ASSERT
2564 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2565 ", integrity-checker=on"
2567 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
2570 #ifdef CONFIG_BLK_DEV_ZONED
2576 pr_info("Btrfs loaded, crc32c=%s%s\n", crc32c_impl(), options);
2579 static int __init init_btrfs_fs(void)
2585 err = btrfs_init_sysfs();
2589 btrfs_init_compress();
2591 err = btrfs_init_cachep();
2595 err = extent_io_init();
2599 err = extent_state_cache_init();
2601 goto free_extent_io;
2603 err = extent_map_init();
2605 goto free_extent_state_cache;
2607 err = ordered_data_init();
2609 goto free_extent_map;
2611 err = btrfs_delayed_inode_init();
2613 goto free_ordered_data;
2615 err = btrfs_auto_defrag_init();
2617 goto free_delayed_inode;
2619 err = btrfs_delayed_ref_init();
2621 goto free_auto_defrag;
2623 err = btrfs_prelim_ref_init();
2625 goto free_delayed_ref;
2627 err = btrfs_end_io_wq_init();
2629 goto free_prelim_ref;
2631 err = btrfs_interface_init();
2633 goto free_end_io_wq;
2635 btrfs_print_mod_info();
2637 err = btrfs_run_sanity_tests();
2639 goto unregister_ioctl;
2641 err = register_filesystem(&btrfs_fs_type);
2643 goto unregister_ioctl;
2648 btrfs_interface_exit();
2650 btrfs_end_io_wq_exit();
2652 btrfs_prelim_ref_exit();
2654 btrfs_delayed_ref_exit();
2656 btrfs_auto_defrag_exit();
2658 btrfs_delayed_inode_exit();
2660 ordered_data_exit();
2663 free_extent_state_cache:
2664 extent_state_cache_exit();
2668 btrfs_destroy_cachep();
2670 btrfs_exit_compress();
2676 static void __exit exit_btrfs_fs(void)
2678 btrfs_destroy_cachep();
2679 btrfs_delayed_ref_exit();
2680 btrfs_auto_defrag_exit();
2681 btrfs_delayed_inode_exit();
2682 btrfs_prelim_ref_exit();
2683 ordered_data_exit();
2685 extent_state_cache_exit();
2687 btrfs_interface_exit();
2688 btrfs_end_io_wq_exit();
2689 unregister_filesystem(&btrfs_fs_type);
2691 btrfs_cleanup_fs_uuids();
2692 btrfs_exit_compress();
2695 late_initcall(init_btrfs_fs);
2696 module_exit(exit_btrfs_fs)
2698 MODULE_LICENSE("GPL");
2699 MODULE_SOFTDEP("pre: crc32c");
2700 MODULE_SOFTDEP("pre: xxhash64");
2701 MODULE_SOFTDEP("pre: sha256");
2702 MODULE_SOFTDEP("pre: blake2b-256");