2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/blkdev.h>
20 #include <linux/module.h>
21 #include <linux/buffer_head.h>
23 #include <linux/pagemap.h>
24 #include <linux/highmem.h>
25 #include <linux/time.h>
26 #include <linux/init.h>
27 #include <linux/seq_file.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mount.h>
31 #include <linux/mpage.h>
32 #include <linux/swap.h>
33 #include <linux/writeback.h>
34 #include <linux/statfs.h>
35 #include <linux/compat.h>
36 #include <linux/parser.h>
37 #include <linux/ctype.h>
38 #include <linux/namei.h>
39 #include <linux/miscdevice.h>
40 #include <linux/magic.h>
41 #include <linux/slab.h>
42 #include <linux/cleancache.h>
43 #include <linux/ratelimit.h>
44 #include <linux/btrfs.h>
45 #include "delayed-inode.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "print-tree.h"
56 #include "compression.h"
57 #include "rcu-string.h"
58 #include "dev-replace.h"
59 #include "free-space-cache.h"
61 #include "tests/btrfs-tests.h"
64 #define CREATE_TRACE_POINTS
65 #include <trace/events/btrfs.h>
67 static const struct super_operations btrfs_super_ops
;
68 static struct file_system_type btrfs_fs_type
;
70 static int btrfs_remount(struct super_block
*sb
, int *flags
, char *data
);
72 const char *btrfs_decode_error(int errno
)
74 char *errstr
= "unknown";
78 errstr
= "IO failure";
81 errstr
= "Out of memory";
84 errstr
= "Readonly filesystem";
87 errstr
= "Object already exists";
90 errstr
= "No space left";
93 errstr
= "No such entry";
100 static void save_error_info(struct btrfs_fs_info
*fs_info
)
103 * today we only save the error info into ram. Long term we'll
104 * also send it down to the disk
106 set_bit(BTRFS_FS_STATE_ERROR
, &fs_info
->fs_state
);
109 /* btrfs handle error by forcing the filesystem readonly */
110 static void btrfs_handle_error(struct btrfs_fs_info
*fs_info
)
112 struct super_block
*sb
= fs_info
->sb
;
114 if (sb
->s_flags
& MS_RDONLY
)
117 if (test_bit(BTRFS_FS_STATE_ERROR
, &fs_info
->fs_state
)) {
118 sb
->s_flags
|= MS_RDONLY
;
119 btrfs_info(fs_info
, "forced readonly");
121 * Note that a running device replace operation is not
122 * canceled here although there is no way to update
123 * the progress. It would add the risk of a deadlock,
124 * therefore the canceling is ommited. The only penalty
125 * is that some I/O remains active until the procedure
126 * completes. The next time when the filesystem is
127 * mounted writeable again, the device replace
128 * operation continues.
135 * __btrfs_std_error decodes expected errors from the caller and
136 * invokes the approciate error response.
139 void __btrfs_std_error(struct btrfs_fs_info
*fs_info
, const char *function
,
140 unsigned int line
, int errno
, const char *fmt
, ...)
142 struct super_block
*sb
= fs_info
->sb
;
146 * Special case: if the error is EROFS, and we're already
147 * under MS_RDONLY, then it is safe here.
149 if (errno
== -EROFS
&& (sb
->s_flags
& MS_RDONLY
))
152 errstr
= btrfs_decode_error(errno
);
154 struct va_format vaf
;
162 "BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
163 sb
->s_id
, function
, line
, errno
, errstr
, &vaf
);
166 printk(KERN_CRIT
"BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
167 sb
->s_id
, function
, line
, errno
, errstr
);
170 /* Don't go through full error handling during mount */
171 save_error_info(fs_info
);
172 if (sb
->s_flags
& MS_BORN
)
173 btrfs_handle_error(fs_info
);
176 static const char * const logtypes
[] = {
187 void btrfs_printk(const struct btrfs_fs_info
*fs_info
, const char *fmt
, ...)
189 struct super_block
*sb
= fs_info
->sb
;
191 struct va_format vaf
;
193 const char *type
= logtypes
[4];
198 kern_level
= printk_get_level(fmt
);
200 size_t size
= printk_skip_level(fmt
) - fmt
;
201 memcpy(lvl
, fmt
, size
);
204 type
= logtypes
[kern_level
- '0'];
211 printk("%sBTRFS %s (device %s): %pV\n", lvl
, type
, sb
->s_id
, &vaf
);
218 void __btrfs_std_error(struct btrfs_fs_info
*fs_info
, const char *function
,
219 unsigned int line
, int errno
, const char *fmt
, ...)
221 struct super_block
*sb
= fs_info
->sb
;
224 * Special case: if the error is EROFS, and we're already
225 * under MS_RDONLY, then it is safe here.
227 if (errno
== -EROFS
&& (sb
->s_flags
& MS_RDONLY
))
230 /* Don't go through full error handling during mount */
231 if (sb
->s_flags
& MS_BORN
) {
232 save_error_info(fs_info
);
233 btrfs_handle_error(fs_info
);
239 * We only mark the transaction aborted and then set the file system read-only.
240 * This will prevent new transactions from starting or trying to join this
243 * This means that error recovery at the call site is limited to freeing
244 * any local memory allocations and passing the error code up without
245 * further cleanup. The transaction should complete as it normally would
246 * in the call path but will return -EIO.
248 * We'll complete the cleanup in btrfs_end_transaction and
249 * btrfs_commit_transaction.
252 void __btrfs_abort_transaction(struct btrfs_trans_handle
*trans
,
253 struct btrfs_root
*root
, const char *function
,
254 unsigned int line
, int errno
)
256 trans
->aborted
= errno
;
257 /* Nothing used. The other threads that have joined this
258 * transaction may be able to continue. */
259 if (!trans
->blocks_used
&& list_empty(&trans
->new_bgs
)) {
262 errstr
= btrfs_decode_error(errno
);
263 btrfs_warn(root
->fs_info
,
264 "%s:%d: Aborting unused transaction(%s).",
265 function
, line
, errstr
);
268 ACCESS_ONCE(trans
->transaction
->aborted
) = errno
;
269 /* Wake up anybody who may be waiting on this transaction */
270 wake_up(&root
->fs_info
->transaction_wait
);
271 wake_up(&root
->fs_info
->transaction_blocked_wait
);
272 __btrfs_std_error(root
->fs_info
, function
, line
, errno
, NULL
);
275 * __btrfs_panic decodes unexpected, fatal errors from the caller,
276 * issues an alert, and either panics or BUGs, depending on mount options.
279 void __btrfs_panic(struct btrfs_fs_info
*fs_info
, const char *function
,
280 unsigned int line
, int errno
, const char *fmt
, ...)
282 char *s_id
= "<unknown>";
284 struct va_format vaf
= { .fmt
= fmt
};
288 s_id
= fs_info
->sb
->s_id
;
293 errstr
= btrfs_decode_error(errno
);
294 if (fs_info
&& (fs_info
->mount_opt
& BTRFS_MOUNT_PANIC_ON_FATAL_ERROR
))
295 panic(KERN_CRIT
"BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
296 s_id
, function
, line
, &vaf
, errno
, errstr
);
298 btrfs_crit(fs_info
, "panic in %s:%d: %pV (errno=%d %s)",
299 function
, line
, &vaf
, errno
, errstr
);
301 /* Caller calls BUG() */
304 static void btrfs_put_super(struct super_block
*sb
)
306 close_ctree(btrfs_sb(sb
)->tree_root
);
310 Opt_degraded
, Opt_subvol
, Opt_subvolid
, Opt_device
, Opt_nodatasum
,
311 Opt_nodatacow
, Opt_max_inline
, Opt_alloc_start
, Opt_nobarrier
, Opt_ssd
,
312 Opt_nossd
, Opt_ssd_spread
, Opt_thread_pool
, Opt_noacl
, Opt_compress
,
313 Opt_compress_type
, Opt_compress_force
, Opt_compress_force_type
,
314 Opt_notreelog
, Opt_ratio
, Opt_flushoncommit
, Opt_discard
,
315 Opt_space_cache
, Opt_clear_cache
, Opt_user_subvol_rm_allowed
,
316 Opt_enospc_debug
, Opt_subvolrootid
, Opt_defrag
, Opt_inode_cache
,
317 Opt_no_space_cache
, Opt_recovery
, Opt_skip_balance
,
318 Opt_check_integrity
, Opt_check_integrity_including_extent_data
,
319 Opt_check_integrity_print_mask
, Opt_fatal_errors
, Opt_rescan_uuid_tree
,
320 Opt_commit_interval
, Opt_barrier
, Opt_nodefrag
, Opt_nodiscard
,
321 Opt_noenospc_debug
, Opt_noflushoncommit
, Opt_acl
, Opt_datacow
,
322 Opt_datasum
, Opt_treelog
, Opt_noinode_cache
,
326 static match_table_t tokens
= {
327 {Opt_degraded
, "degraded"},
328 {Opt_subvol
, "subvol=%s"},
329 {Opt_subvolid
, "subvolid=%s"},
330 {Opt_device
, "device=%s"},
331 {Opt_nodatasum
, "nodatasum"},
332 {Opt_datasum
, "datasum"},
333 {Opt_nodatacow
, "nodatacow"},
334 {Opt_datacow
, "datacow"},
335 {Opt_nobarrier
, "nobarrier"},
336 {Opt_barrier
, "barrier"},
337 {Opt_max_inline
, "max_inline=%s"},
338 {Opt_alloc_start
, "alloc_start=%s"},
339 {Opt_thread_pool
, "thread_pool=%d"},
340 {Opt_compress
, "compress"},
341 {Opt_compress_type
, "compress=%s"},
342 {Opt_compress_force
, "compress-force"},
343 {Opt_compress_force_type
, "compress-force=%s"},
345 {Opt_ssd_spread
, "ssd_spread"},
346 {Opt_nossd
, "nossd"},
348 {Opt_noacl
, "noacl"},
349 {Opt_notreelog
, "notreelog"},
350 {Opt_treelog
, "treelog"},
351 {Opt_flushoncommit
, "flushoncommit"},
352 {Opt_noflushoncommit
, "noflushoncommit"},
353 {Opt_ratio
, "metadata_ratio=%d"},
354 {Opt_discard
, "discard"},
355 {Opt_nodiscard
, "nodiscard"},
356 {Opt_space_cache
, "space_cache"},
357 {Opt_clear_cache
, "clear_cache"},
358 {Opt_user_subvol_rm_allowed
, "user_subvol_rm_allowed"},
359 {Opt_enospc_debug
, "enospc_debug"},
360 {Opt_noenospc_debug
, "noenospc_debug"},
361 {Opt_subvolrootid
, "subvolrootid=%d"},
362 {Opt_defrag
, "autodefrag"},
363 {Opt_nodefrag
, "noautodefrag"},
364 {Opt_inode_cache
, "inode_cache"},
365 {Opt_noinode_cache
, "noinode_cache"},
366 {Opt_no_space_cache
, "nospace_cache"},
367 {Opt_recovery
, "recovery"},
368 {Opt_skip_balance
, "skip_balance"},
369 {Opt_check_integrity
, "check_int"},
370 {Opt_check_integrity_including_extent_data
, "check_int_data"},
371 {Opt_check_integrity_print_mask
, "check_int_print_mask=%d"},
372 {Opt_rescan_uuid_tree
, "rescan_uuid_tree"},
373 {Opt_fatal_errors
, "fatal_errors=%s"},
374 {Opt_commit_interval
, "commit=%d"},
379 * Regular mount options parser. Everything that is needed only when
380 * reading in a new superblock is parsed here.
381 * XXX JDM: This needs to be cleaned up for remount.
383 int btrfs_parse_options(struct btrfs_root
*root
, char *options
)
385 struct btrfs_fs_info
*info
= root
->fs_info
;
386 substring_t args
[MAX_OPT_ARGS
];
387 char *p
, *num
, *orig
= NULL
;
392 bool compress_force
= false;
394 cache_gen
= btrfs_super_cache_generation(root
->fs_info
->super_copy
);
396 btrfs_set_opt(info
->mount_opt
, SPACE_CACHE
);
402 * strsep changes the string, duplicate it because parse_options
405 options
= kstrdup(options
, GFP_NOFS
);
411 while ((p
= strsep(&options
, ",")) != NULL
) {
416 token
= match_token(p
, tokens
, args
);
419 btrfs_info(root
->fs_info
, "allowing degraded mounts");
420 btrfs_set_opt(info
->mount_opt
, DEGRADED
);
424 case Opt_subvolrootid
:
427 * These are parsed by btrfs_parse_early_options
428 * and can be happily ignored here.
432 btrfs_set_and_info(root
, NODATASUM
,
433 "setting nodatasum");
436 if (btrfs_test_opt(root
, NODATASUM
)) {
437 if (btrfs_test_opt(root
, NODATACOW
))
438 btrfs_info(root
->fs_info
, "setting datasum, datacow enabled");
440 btrfs_info(root
->fs_info
, "setting datasum");
442 btrfs_clear_opt(info
->mount_opt
, NODATACOW
);
443 btrfs_clear_opt(info
->mount_opt
, NODATASUM
);
446 if (!btrfs_test_opt(root
, NODATACOW
)) {
447 if (!btrfs_test_opt(root
, COMPRESS
) ||
448 !btrfs_test_opt(root
, FORCE_COMPRESS
)) {
449 btrfs_info(root
->fs_info
,
450 "setting nodatacow, compression disabled");
452 btrfs_info(root
->fs_info
, "setting nodatacow");
455 btrfs_clear_opt(info
->mount_opt
, COMPRESS
);
456 btrfs_clear_opt(info
->mount_opt
, FORCE_COMPRESS
);
457 btrfs_set_opt(info
->mount_opt
, NODATACOW
);
458 btrfs_set_opt(info
->mount_opt
, NODATASUM
);
461 btrfs_clear_and_info(root
, NODATACOW
,
464 case Opt_compress_force
:
465 case Opt_compress_force_type
:
466 compress_force
= true;
469 case Opt_compress_type
:
470 if (token
== Opt_compress
||
471 token
== Opt_compress_force
||
472 strcmp(args
[0].from
, "zlib") == 0) {
473 compress_type
= "zlib";
474 info
->compress_type
= BTRFS_COMPRESS_ZLIB
;
475 btrfs_set_opt(info
->mount_opt
, COMPRESS
);
476 btrfs_clear_opt(info
->mount_opt
, NODATACOW
);
477 btrfs_clear_opt(info
->mount_opt
, NODATASUM
);
478 } else if (strcmp(args
[0].from
, "lzo") == 0) {
479 compress_type
= "lzo";
480 info
->compress_type
= BTRFS_COMPRESS_LZO
;
481 btrfs_set_opt(info
->mount_opt
, COMPRESS
);
482 btrfs_clear_opt(info
->mount_opt
, NODATACOW
);
483 btrfs_clear_opt(info
->mount_opt
, NODATASUM
);
484 btrfs_set_fs_incompat(info
, COMPRESS_LZO
);
485 } else if (strncmp(args
[0].from
, "no", 2) == 0) {
486 compress_type
= "no";
487 btrfs_clear_opt(info
->mount_opt
, COMPRESS
);
488 btrfs_clear_opt(info
->mount_opt
, FORCE_COMPRESS
);
489 compress_force
= false;
495 if (compress_force
) {
496 btrfs_set_and_info(root
, FORCE_COMPRESS
,
497 "force %s compression",
500 if (!btrfs_test_opt(root
, COMPRESS
))
501 btrfs_info(root
->fs_info
,
502 "btrfs: use %s compression",
505 * If we remount from compress-force=xxx to
506 * compress=xxx, we need clear FORCE_COMPRESS
507 * flag, otherwise, there is no way for users
508 * to disable forcible compression separately.
510 btrfs_clear_opt(info
->mount_opt
, FORCE_COMPRESS
);
514 btrfs_set_and_info(root
, SSD
,
515 "use ssd allocation scheme");
518 btrfs_set_and_info(root
, SSD_SPREAD
,
519 "use spread ssd allocation scheme");
520 btrfs_set_opt(info
->mount_opt
, SSD
);
523 btrfs_set_and_info(root
, NOSSD
,
524 "not using ssd allocation scheme");
525 btrfs_clear_opt(info
->mount_opt
, SSD
);
528 btrfs_clear_and_info(root
, NOBARRIER
,
529 "turning on barriers");
532 btrfs_set_and_info(root
, NOBARRIER
,
533 "turning off barriers");
535 case Opt_thread_pool
:
536 ret
= match_int(&args
[0], &intarg
);
539 } else if (intarg
> 0) {
540 info
->thread_pool_size
= intarg
;
547 num
= match_strdup(&args
[0]);
549 info
->max_inline
= memparse(num
, NULL
);
552 if (info
->max_inline
) {
553 info
->max_inline
= min_t(u64
,
557 btrfs_info(root
->fs_info
, "max_inline at %llu",
564 case Opt_alloc_start
:
565 num
= match_strdup(&args
[0]);
567 mutex_lock(&info
->chunk_mutex
);
568 info
->alloc_start
= memparse(num
, NULL
);
569 mutex_unlock(&info
->chunk_mutex
);
571 btrfs_info(root
->fs_info
, "allocations start at %llu",
579 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
580 root
->fs_info
->sb
->s_flags
|= MS_POSIXACL
;
583 btrfs_err(root
->fs_info
,
584 "support for ACL not compiled in!");
589 root
->fs_info
->sb
->s_flags
&= ~MS_POSIXACL
;
592 btrfs_set_and_info(root
, NOTREELOG
,
593 "disabling tree log");
596 btrfs_clear_and_info(root
, NOTREELOG
,
597 "enabling tree log");
599 case Opt_flushoncommit
:
600 btrfs_set_and_info(root
, FLUSHONCOMMIT
,
601 "turning on flush-on-commit");
603 case Opt_noflushoncommit
:
604 btrfs_clear_and_info(root
, FLUSHONCOMMIT
,
605 "turning off flush-on-commit");
608 ret
= match_int(&args
[0], &intarg
);
611 } else if (intarg
>= 0) {
612 info
->metadata_ratio
= intarg
;
613 btrfs_info(root
->fs_info
, "metadata ratio %d",
614 info
->metadata_ratio
);
621 btrfs_set_and_info(root
, DISCARD
,
622 "turning on discard");
625 btrfs_clear_and_info(root
, DISCARD
,
626 "turning off discard");
628 case Opt_space_cache
:
629 btrfs_set_and_info(root
, SPACE_CACHE
,
630 "enabling disk space caching");
632 case Opt_rescan_uuid_tree
:
633 btrfs_set_opt(info
->mount_opt
, RESCAN_UUID_TREE
);
635 case Opt_no_space_cache
:
636 btrfs_clear_and_info(root
, SPACE_CACHE
,
637 "disabling disk space caching");
639 case Opt_inode_cache
:
640 btrfs_set_pending_and_info(info
, INODE_MAP_CACHE
,
641 "enabling inode map caching");
643 case Opt_noinode_cache
:
644 btrfs_clear_pending_and_info(info
, INODE_MAP_CACHE
,
645 "disabling inode map caching");
647 case Opt_clear_cache
:
648 btrfs_set_and_info(root
, CLEAR_CACHE
,
649 "force clearing of disk cache");
651 case Opt_user_subvol_rm_allowed
:
652 btrfs_set_opt(info
->mount_opt
, USER_SUBVOL_RM_ALLOWED
);
654 case Opt_enospc_debug
:
655 btrfs_set_opt(info
->mount_opt
, ENOSPC_DEBUG
);
657 case Opt_noenospc_debug
:
658 btrfs_clear_opt(info
->mount_opt
, ENOSPC_DEBUG
);
661 btrfs_set_and_info(root
, AUTO_DEFRAG
,
662 "enabling auto defrag");
665 btrfs_clear_and_info(root
, AUTO_DEFRAG
,
666 "disabling auto defrag");
669 btrfs_info(root
->fs_info
, "enabling auto recovery");
670 btrfs_set_opt(info
->mount_opt
, RECOVERY
);
672 case Opt_skip_balance
:
673 btrfs_set_opt(info
->mount_opt
, SKIP_BALANCE
);
675 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
676 case Opt_check_integrity_including_extent_data
:
677 btrfs_info(root
->fs_info
,
678 "enabling check integrity including extent data");
679 btrfs_set_opt(info
->mount_opt
,
680 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA
);
681 btrfs_set_opt(info
->mount_opt
, CHECK_INTEGRITY
);
683 case Opt_check_integrity
:
684 btrfs_info(root
->fs_info
, "enabling check integrity");
685 btrfs_set_opt(info
->mount_opt
, CHECK_INTEGRITY
);
687 case Opt_check_integrity_print_mask
:
688 ret
= match_int(&args
[0], &intarg
);
691 } else if (intarg
>= 0) {
692 info
->check_integrity_print_mask
= intarg
;
693 btrfs_info(root
->fs_info
, "check_integrity_print_mask 0x%x",
694 info
->check_integrity_print_mask
);
701 case Opt_check_integrity_including_extent_data
:
702 case Opt_check_integrity
:
703 case Opt_check_integrity_print_mask
:
704 btrfs_err(root
->fs_info
,
705 "support for check_integrity* not compiled in!");
709 case Opt_fatal_errors
:
710 if (strcmp(args
[0].from
, "panic") == 0)
711 btrfs_set_opt(info
->mount_opt
,
712 PANIC_ON_FATAL_ERROR
);
713 else if (strcmp(args
[0].from
, "bug") == 0)
714 btrfs_clear_opt(info
->mount_opt
,
715 PANIC_ON_FATAL_ERROR
);
721 case Opt_commit_interval
:
723 ret
= match_int(&args
[0], &intarg
);
725 btrfs_err(root
->fs_info
, "invalid commit interval");
731 btrfs_warn(root
->fs_info
, "excessive commit interval %d",
734 info
->commit_interval
= intarg
;
736 btrfs_info(root
->fs_info
, "using default commit interval %ds",
737 BTRFS_DEFAULT_COMMIT_INTERVAL
);
738 info
->commit_interval
= BTRFS_DEFAULT_COMMIT_INTERVAL
;
742 btrfs_info(root
->fs_info
, "unrecognized mount option '%s'", p
);
750 if (!ret
&& btrfs_test_opt(root
, SPACE_CACHE
))
751 btrfs_info(root
->fs_info
, "disk space caching is enabled");
757 * Parse mount options that are required early in the mount process.
759 * All other options will be parsed on much later in the mount process and
760 * only when we need to allocate a new super block.
762 static int btrfs_parse_early_options(const char *options
, fmode_t flags
,
763 void *holder
, char **subvol_name
, u64
*subvol_objectid
,
764 struct btrfs_fs_devices
**fs_devices
)
766 substring_t args
[MAX_OPT_ARGS
];
767 char *device_name
, *opts
, *orig
, *p
;
775 * strsep changes the string, duplicate it because parse_options
778 opts
= kstrdup(options
, GFP_KERNEL
);
783 while ((p
= strsep(&opts
, ",")) != NULL
) {
788 token
= match_token(p
, tokens
, args
);
792 *subvol_name
= match_strdup(&args
[0]);
799 num
= match_strdup(&args
[0]);
801 *subvol_objectid
= memparse(num
, NULL
);
803 /* we want the original fs_tree */
804 if (!*subvol_objectid
)
806 BTRFS_FS_TREE_OBJECTID
;
812 case Opt_subvolrootid
:
814 "BTRFS: 'subvolrootid' mount option is deprecated and has "
818 device_name
= match_strdup(&args
[0]);
823 error
= btrfs_scan_one_device(device_name
,
824 flags
, holder
, fs_devices
);
839 static char *get_subvol_name_from_objectid(struct btrfs_fs_info
*fs_info
,
842 struct btrfs_root
*root
= fs_info
->tree_root
;
843 struct btrfs_root
*fs_root
;
844 struct btrfs_root_ref
*root_ref
;
845 struct btrfs_inode_ref
*inode_ref
;
846 struct btrfs_key key
;
847 struct btrfs_path
*path
= NULL
;
848 char *name
= NULL
, *ptr
;
853 path
= btrfs_alloc_path();
858 path
->leave_spinning
= 1;
860 name
= kmalloc(PATH_MAX
, GFP_NOFS
);
865 ptr
= name
+ PATH_MAX
- 1;
869 * Walk up the subvolume trees in the tree of tree roots by root
870 * backrefs until we hit the top-level subvolume.
872 while (subvol_objectid
!= BTRFS_FS_TREE_OBJECTID
) {
873 key
.objectid
= subvol_objectid
;
874 key
.type
= BTRFS_ROOT_BACKREF_KEY
;
875 key
.offset
= (u64
)-1;
877 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
880 } else if (ret
> 0) {
881 ret
= btrfs_previous_item(root
, path
, subvol_objectid
,
882 BTRFS_ROOT_BACKREF_KEY
);
885 } else if (ret
> 0) {
891 btrfs_item_key_to_cpu(path
->nodes
[0], &key
, path
->slots
[0]);
892 subvol_objectid
= key
.offset
;
894 root_ref
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
895 struct btrfs_root_ref
);
896 len
= btrfs_root_ref_name_len(path
->nodes
[0], root_ref
);
902 read_extent_buffer(path
->nodes
[0], ptr
+ 1,
903 (unsigned long)(root_ref
+ 1), len
);
905 dirid
= btrfs_root_ref_dirid(path
->nodes
[0], root_ref
);
906 btrfs_release_path(path
);
908 key
.objectid
= subvol_objectid
;
909 key
.type
= BTRFS_ROOT_ITEM_KEY
;
910 key
.offset
= (u64
)-1;
911 fs_root
= btrfs_read_fs_root_no_name(fs_info
, &key
);
912 if (IS_ERR(fs_root
)) {
913 ret
= PTR_ERR(fs_root
);
918 * Walk up the filesystem tree by inode refs until we hit the
921 while (dirid
!= BTRFS_FIRST_FREE_OBJECTID
) {
922 key
.objectid
= dirid
;
923 key
.type
= BTRFS_INODE_REF_KEY
;
924 key
.offset
= (u64
)-1;
926 ret
= btrfs_search_slot(NULL
, fs_root
, &key
, path
, 0, 0);
929 } else if (ret
> 0) {
930 ret
= btrfs_previous_item(fs_root
, path
, dirid
,
931 BTRFS_INODE_REF_KEY
);
934 } else if (ret
> 0) {
940 btrfs_item_key_to_cpu(path
->nodes
[0], &key
, path
->slots
[0]);
943 inode_ref
= btrfs_item_ptr(path
->nodes
[0],
945 struct btrfs_inode_ref
);
946 len
= btrfs_inode_ref_name_len(path
->nodes
[0],
953 read_extent_buffer(path
->nodes
[0], ptr
+ 1,
954 (unsigned long)(inode_ref
+ 1), len
);
956 btrfs_release_path(path
);
960 btrfs_free_path(path
);
961 if (ptr
== name
+ PATH_MAX
- 1) {
965 memmove(name
, ptr
, name
+ PATH_MAX
- ptr
);
970 btrfs_free_path(path
);
975 static int get_default_subvol_objectid(struct btrfs_fs_info
*fs_info
, u64
*objectid
)
977 struct btrfs_root
*root
= fs_info
->tree_root
;
978 struct btrfs_dir_item
*di
;
979 struct btrfs_path
*path
;
980 struct btrfs_key location
;
983 path
= btrfs_alloc_path();
986 path
->leave_spinning
= 1;
989 * Find the "default" dir item which points to the root item that we
990 * will mount by default if we haven't been given a specific subvolume
993 dir_id
= btrfs_super_root_dir(fs_info
->super_copy
);
994 di
= btrfs_lookup_dir_item(NULL
, root
, path
, dir_id
, "default", 7, 0);
996 btrfs_free_path(path
);
1001 * Ok the default dir item isn't there. This is weird since
1002 * it's always been there, but don't freak out, just try and
1003 * mount the top-level subvolume.
1005 btrfs_free_path(path
);
1006 *objectid
= BTRFS_FS_TREE_OBJECTID
;
1010 btrfs_dir_item_key_to_cpu(path
->nodes
[0], di
, &location
);
1011 btrfs_free_path(path
);
1012 *objectid
= location
.objectid
;
1016 static int btrfs_fill_super(struct super_block
*sb
,
1017 struct btrfs_fs_devices
*fs_devices
,
1018 void *data
, int silent
)
1020 struct inode
*inode
;
1021 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
1022 struct btrfs_key key
;
1025 sb
->s_maxbytes
= MAX_LFS_FILESIZE
;
1026 sb
->s_magic
= BTRFS_SUPER_MAGIC
;
1027 sb
->s_op
= &btrfs_super_ops
;
1028 sb
->s_d_op
= &btrfs_dentry_operations
;
1029 sb
->s_export_op
= &btrfs_export_ops
;
1030 sb
->s_xattr
= btrfs_xattr_handlers
;
1031 sb
->s_time_gran
= 1;
1032 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
1033 sb
->s_flags
|= MS_POSIXACL
;
1035 sb
->s_flags
|= MS_I_VERSION
;
1036 sb
->s_iflags
|= SB_I_CGROUPWB
;
1037 err
= open_ctree(sb
, fs_devices
, (char *)data
);
1039 printk(KERN_ERR
"BTRFS: open_ctree failed\n");
1043 key
.objectid
= BTRFS_FIRST_FREE_OBJECTID
;
1044 key
.type
= BTRFS_INODE_ITEM_KEY
;
1046 inode
= btrfs_iget(sb
, &key
, fs_info
->fs_root
, NULL
);
1047 if (IS_ERR(inode
)) {
1048 err
= PTR_ERR(inode
);
1052 sb
->s_root
= d_make_root(inode
);
1058 save_mount_options(sb
, data
);
1059 cleancache_init_fs(sb
);
1060 sb
->s_flags
|= MS_ACTIVE
;
1064 close_ctree(fs_info
->tree_root
);
1068 int btrfs_sync_fs(struct super_block
*sb
, int wait
)
1070 struct btrfs_trans_handle
*trans
;
1071 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
1072 struct btrfs_root
*root
= fs_info
->tree_root
;
1074 trace_btrfs_sync_fs(wait
);
1077 filemap_flush(fs_info
->btree_inode
->i_mapping
);
1081 btrfs_wait_ordered_roots(fs_info
, -1);
1083 trans
= btrfs_attach_transaction_barrier(root
);
1084 if (IS_ERR(trans
)) {
1085 /* no transaction, don't bother */
1086 if (PTR_ERR(trans
) == -ENOENT
) {
1088 * Exit unless we have some pending changes
1089 * that need to go through commit
1091 if (fs_info
->pending_changes
== 0)
1094 * A non-blocking test if the fs is frozen. We must not
1095 * start a new transaction here otherwise a deadlock
1096 * happens. The pending operations are delayed to the
1097 * next commit after thawing.
1099 if (__sb_start_write(sb
, SB_FREEZE_WRITE
, false))
1100 __sb_end_write(sb
, SB_FREEZE_WRITE
);
1103 trans
= btrfs_start_transaction(root
, 0);
1106 return PTR_ERR(trans
);
1108 return btrfs_commit_transaction(trans
, root
);
1111 static int btrfs_show_options(struct seq_file
*seq
, struct dentry
*dentry
)
1113 struct btrfs_fs_info
*info
= btrfs_sb(dentry
->d_sb
);
1114 struct btrfs_root
*root
= info
->tree_root
;
1115 char *compress_type
;
1117 if (btrfs_test_opt(root
, DEGRADED
))
1118 seq_puts(seq
, ",degraded");
1119 if (btrfs_test_opt(root
, NODATASUM
))
1120 seq_puts(seq
, ",nodatasum");
1121 if (btrfs_test_opt(root
, NODATACOW
))
1122 seq_puts(seq
, ",nodatacow");
1123 if (btrfs_test_opt(root
, NOBARRIER
))
1124 seq_puts(seq
, ",nobarrier");
1125 if (info
->max_inline
!= BTRFS_DEFAULT_MAX_INLINE
)
1126 seq_printf(seq
, ",max_inline=%llu", info
->max_inline
);
1127 if (info
->alloc_start
!= 0)
1128 seq_printf(seq
, ",alloc_start=%llu", info
->alloc_start
);
1129 if (info
->thread_pool_size
!= min_t(unsigned long,
1130 num_online_cpus() + 2, 8))
1131 seq_printf(seq
, ",thread_pool=%d", info
->thread_pool_size
);
1132 if (btrfs_test_opt(root
, COMPRESS
)) {
1133 if (info
->compress_type
== BTRFS_COMPRESS_ZLIB
)
1134 compress_type
= "zlib";
1136 compress_type
= "lzo";
1137 if (btrfs_test_opt(root
, FORCE_COMPRESS
))
1138 seq_printf(seq
, ",compress-force=%s", compress_type
);
1140 seq_printf(seq
, ",compress=%s", compress_type
);
1142 if (btrfs_test_opt(root
, NOSSD
))
1143 seq_puts(seq
, ",nossd");
1144 if (btrfs_test_opt(root
, SSD_SPREAD
))
1145 seq_puts(seq
, ",ssd_spread");
1146 else if (btrfs_test_opt(root
, SSD
))
1147 seq_puts(seq
, ",ssd");
1148 if (btrfs_test_opt(root
, NOTREELOG
))
1149 seq_puts(seq
, ",notreelog");
1150 if (btrfs_test_opt(root
, FLUSHONCOMMIT
))
1151 seq_puts(seq
, ",flushoncommit");
1152 if (btrfs_test_opt(root
, DISCARD
))
1153 seq_puts(seq
, ",discard");
1154 if (!(root
->fs_info
->sb
->s_flags
& MS_POSIXACL
))
1155 seq_puts(seq
, ",noacl");
1156 if (btrfs_test_opt(root
, SPACE_CACHE
))
1157 seq_puts(seq
, ",space_cache");
1159 seq_puts(seq
, ",nospace_cache");
1160 if (btrfs_test_opt(root
, RESCAN_UUID_TREE
))
1161 seq_puts(seq
, ",rescan_uuid_tree");
1162 if (btrfs_test_opt(root
, CLEAR_CACHE
))
1163 seq_puts(seq
, ",clear_cache");
1164 if (btrfs_test_opt(root
, USER_SUBVOL_RM_ALLOWED
))
1165 seq_puts(seq
, ",user_subvol_rm_allowed");
1166 if (btrfs_test_opt(root
, ENOSPC_DEBUG
))
1167 seq_puts(seq
, ",enospc_debug");
1168 if (btrfs_test_opt(root
, AUTO_DEFRAG
))
1169 seq_puts(seq
, ",autodefrag");
1170 if (btrfs_test_opt(root
, INODE_MAP_CACHE
))
1171 seq_puts(seq
, ",inode_cache");
1172 if (btrfs_test_opt(root
, SKIP_BALANCE
))
1173 seq_puts(seq
, ",skip_balance");
1174 if (btrfs_test_opt(root
, RECOVERY
))
1175 seq_puts(seq
, ",recovery");
1176 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1177 if (btrfs_test_opt(root
, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA
))
1178 seq_puts(seq
, ",check_int_data");
1179 else if (btrfs_test_opt(root
, CHECK_INTEGRITY
))
1180 seq_puts(seq
, ",check_int");
1181 if (info
->check_integrity_print_mask
)
1182 seq_printf(seq
, ",check_int_print_mask=%d",
1183 info
->check_integrity_print_mask
);
1185 if (info
->metadata_ratio
)
1186 seq_printf(seq
, ",metadata_ratio=%d",
1187 info
->metadata_ratio
);
1188 if (btrfs_test_opt(root
, PANIC_ON_FATAL_ERROR
))
1189 seq_puts(seq
, ",fatal_errors=panic");
1190 if (info
->commit_interval
!= BTRFS_DEFAULT_COMMIT_INTERVAL
)
1191 seq_printf(seq
, ",commit=%d", info
->commit_interval
);
1192 seq_printf(seq
, ",subvolid=%llu",
1193 BTRFS_I(d_inode(dentry
))->root
->root_key
.objectid
);
1194 seq_puts(seq
, ",subvol=");
1195 seq_dentry(seq
, dentry
, " \t\n\\");
1199 static int btrfs_test_super(struct super_block
*s
, void *data
)
1201 struct btrfs_fs_info
*p
= data
;
1202 struct btrfs_fs_info
*fs_info
= btrfs_sb(s
);
1204 return fs_info
->fs_devices
== p
->fs_devices
;
1207 static int btrfs_set_super(struct super_block
*s
, void *data
)
1209 int err
= set_anon_super(s
, data
);
1211 s
->s_fs_info
= data
;
1216 * subvolumes are identified by ino 256
1218 static inline int is_subvolume_inode(struct inode
*inode
)
1220 if (inode
&& inode
->i_ino
== BTRFS_FIRST_FREE_OBJECTID
)
1226 * This will add subvolid=0 to the argument string while removing any subvol=
1227 * and subvolid= arguments to make sure we get the top-level root for path
1228 * walking to the subvol we want.
1230 static char *setup_root_args(char *args
)
1232 char *buf
, *dst
, *sep
;
1235 return kstrdup("subvolid=0", GFP_NOFS
);
1237 /* The worst case is that we add ",subvolid=0" to the end. */
1238 buf
= dst
= kmalloc(strlen(args
) + strlen(",subvolid=0") + 1, GFP_NOFS
);
1243 sep
= strchrnul(args
, ',');
1244 if (!strstarts(args
, "subvol=") &&
1245 !strstarts(args
, "subvolid=")) {
1246 memcpy(dst
, args
, sep
- args
);
1255 strcpy(dst
, "subvolid=0");
1260 static struct dentry
*mount_subvol(const char *subvol_name
, u64 subvol_objectid
,
1261 int flags
, const char *device_name
,
1264 struct dentry
*root
;
1265 struct vfsmount
*mnt
= NULL
;
1269 newargs
= setup_root_args(data
);
1271 root
= ERR_PTR(-ENOMEM
);
1275 mnt
= vfs_kern_mount(&btrfs_fs_type
, flags
, device_name
, newargs
);
1276 if (PTR_ERR_OR_ZERO(mnt
) == -EBUSY
) {
1277 if (flags
& MS_RDONLY
) {
1278 mnt
= vfs_kern_mount(&btrfs_fs_type
, flags
& ~MS_RDONLY
,
1279 device_name
, newargs
);
1281 mnt
= vfs_kern_mount(&btrfs_fs_type
, flags
| MS_RDONLY
,
1282 device_name
, newargs
);
1284 root
= ERR_CAST(mnt
);
1289 down_write(&mnt
->mnt_sb
->s_umount
);
1290 ret
= btrfs_remount(mnt
->mnt_sb
, &flags
, NULL
);
1291 up_write(&mnt
->mnt_sb
->s_umount
);
1293 root
= ERR_PTR(ret
);
1299 root
= ERR_CAST(mnt
);
1305 if (!subvol_objectid
) {
1306 ret
= get_default_subvol_objectid(btrfs_sb(mnt
->mnt_sb
),
1309 root
= ERR_PTR(ret
);
1313 subvol_name
= get_subvol_name_from_objectid(btrfs_sb(mnt
->mnt_sb
),
1315 if (IS_ERR(subvol_name
)) {
1316 root
= ERR_CAST(subvol_name
);
1323 root
= mount_subtree(mnt
, subvol_name
);
1324 /* mount_subtree() drops our reference on the vfsmount. */
1327 if (!IS_ERR(root
)) {
1328 struct super_block
*s
= root
->d_sb
;
1329 struct inode
*root_inode
= d_inode(root
);
1330 u64 root_objectid
= BTRFS_I(root_inode
)->root
->root_key
.objectid
;
1333 if (!is_subvolume_inode(root_inode
)) {
1334 pr_err("BTRFS: '%s' is not a valid subvolume\n",
1338 if (subvol_objectid
&& root_objectid
!= subvol_objectid
) {
1340 * This will also catch a race condition where a
1341 * subvolume which was passed by ID is renamed and
1342 * another subvolume is renamed over the old location.
1344 pr_err("BTRFS: subvol '%s' does not match subvolid %llu\n",
1345 subvol_name
, subvol_objectid
);
1350 root
= ERR_PTR(ret
);
1351 deactivate_locked_super(s
);
1362 static int parse_security_options(char *orig_opts
,
1363 struct security_mnt_opts
*sec_opts
)
1365 char *secdata
= NULL
;
1368 secdata
= alloc_secdata();
1371 ret
= security_sb_copy_data(orig_opts
, secdata
);
1373 free_secdata(secdata
);
1376 ret
= security_sb_parse_opts_str(secdata
, sec_opts
);
1377 free_secdata(secdata
);
1381 static int setup_security_options(struct btrfs_fs_info
*fs_info
,
1382 struct super_block
*sb
,
1383 struct security_mnt_opts
*sec_opts
)
1388 * Call security_sb_set_mnt_opts() to check whether new sec_opts
1391 ret
= security_sb_set_mnt_opts(sb
, sec_opts
, 0, NULL
);
1395 #ifdef CONFIG_SECURITY
1396 if (!fs_info
->security_opts
.num_mnt_opts
) {
1397 /* first time security setup, copy sec_opts to fs_info */
1398 memcpy(&fs_info
->security_opts
, sec_opts
, sizeof(*sec_opts
));
1401 * Since SELinux(the only one supports security_mnt_opts) does
1402 * NOT support changing context during remount/mount same sb,
1403 * This must be the same or part of the same security options,
1406 security_free_mnt_opts(sec_opts
);
1413 * Find a superblock for the given device / mount point.
1415 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1416 * for multiple device setup. Make sure to keep it in sync.
1418 static struct dentry
*btrfs_mount(struct file_system_type
*fs_type
, int flags
,
1419 const char *device_name
, void *data
)
1421 struct block_device
*bdev
= NULL
;
1422 struct super_block
*s
;
1423 struct btrfs_fs_devices
*fs_devices
= NULL
;
1424 struct btrfs_fs_info
*fs_info
= NULL
;
1425 struct security_mnt_opts new_sec_opts
;
1426 fmode_t mode
= FMODE_READ
;
1427 char *subvol_name
= NULL
;
1428 u64 subvol_objectid
= 0;
1431 if (!(flags
& MS_RDONLY
))
1432 mode
|= FMODE_WRITE
;
1434 error
= btrfs_parse_early_options(data
, mode
, fs_type
,
1435 &subvol_name
, &subvol_objectid
,
1439 return ERR_PTR(error
);
1442 if (subvol_name
|| subvol_objectid
!= BTRFS_FS_TREE_OBJECTID
) {
1443 /* mount_subvol() will free subvol_name. */
1444 return mount_subvol(subvol_name
, subvol_objectid
, flags
,
1448 security_init_mnt_opts(&new_sec_opts
);
1450 error
= parse_security_options(data
, &new_sec_opts
);
1452 return ERR_PTR(error
);
1455 error
= btrfs_scan_one_device(device_name
, mode
, fs_type
, &fs_devices
);
1457 goto error_sec_opts
;
1460 * Setup a dummy root and fs_info for test/set super. This is because
1461 * we don't actually fill this stuff out until open_ctree, but we need
1462 * it for searching for existing supers, so this lets us do that and
1463 * then open_ctree will properly initialize everything later.
1465 fs_info
= kzalloc(sizeof(struct btrfs_fs_info
), GFP_NOFS
);
1468 goto error_sec_opts
;
1471 fs_info
->fs_devices
= fs_devices
;
1473 fs_info
->super_copy
= kzalloc(BTRFS_SUPER_INFO_SIZE
, GFP_NOFS
);
1474 fs_info
->super_for_commit
= kzalloc(BTRFS_SUPER_INFO_SIZE
, GFP_NOFS
);
1475 security_init_mnt_opts(&fs_info
->security_opts
);
1476 if (!fs_info
->super_copy
|| !fs_info
->super_for_commit
) {
1481 error
= btrfs_open_devices(fs_devices
, mode
, fs_type
);
1485 if (!(flags
& MS_RDONLY
) && fs_devices
->rw_devices
== 0) {
1487 goto error_close_devices
;
1490 bdev
= fs_devices
->latest_bdev
;
1491 s
= sget(fs_type
, btrfs_test_super
, btrfs_set_super
, flags
| MS_NOSEC
,
1495 goto error_close_devices
;
1499 btrfs_close_devices(fs_devices
);
1500 free_fs_info(fs_info
);
1501 if ((flags
^ s
->s_flags
) & MS_RDONLY
)
1504 char b
[BDEVNAME_SIZE
];
1506 strlcpy(s
->s_id
, bdevname(bdev
, b
), sizeof(s
->s_id
));
1507 btrfs_sb(s
)->bdev_holder
= fs_type
;
1508 error
= btrfs_fill_super(s
, fs_devices
, data
,
1509 flags
& MS_SILENT
? 1 : 0);
1512 deactivate_locked_super(s
);
1513 goto error_sec_opts
;
1516 fs_info
= btrfs_sb(s
);
1517 error
= setup_security_options(fs_info
, s
, &new_sec_opts
);
1519 deactivate_locked_super(s
);
1520 goto error_sec_opts
;
1523 return dget(s
->s_root
);
1525 error_close_devices
:
1526 btrfs_close_devices(fs_devices
);
1528 free_fs_info(fs_info
);
1530 security_free_mnt_opts(&new_sec_opts
);
1531 return ERR_PTR(error
);
1534 static void btrfs_resize_thread_pool(struct btrfs_fs_info
*fs_info
,
1535 int new_pool_size
, int old_pool_size
)
1537 if (new_pool_size
== old_pool_size
)
1540 fs_info
->thread_pool_size
= new_pool_size
;
1542 btrfs_info(fs_info
, "resize thread pool %d -> %d",
1543 old_pool_size
, new_pool_size
);
1545 btrfs_workqueue_set_max(fs_info
->workers
, new_pool_size
);
1546 btrfs_workqueue_set_max(fs_info
->delalloc_workers
, new_pool_size
);
1547 btrfs_workqueue_set_max(fs_info
->submit_workers
, new_pool_size
);
1548 btrfs_workqueue_set_max(fs_info
->caching_workers
, new_pool_size
);
1549 btrfs_workqueue_set_max(fs_info
->endio_workers
, new_pool_size
);
1550 btrfs_workqueue_set_max(fs_info
->endio_meta_workers
, new_pool_size
);
1551 btrfs_workqueue_set_max(fs_info
->endio_meta_write_workers
,
1553 btrfs_workqueue_set_max(fs_info
->endio_write_workers
, new_pool_size
);
1554 btrfs_workqueue_set_max(fs_info
->endio_freespace_worker
, new_pool_size
);
1555 btrfs_workqueue_set_max(fs_info
->delayed_workers
, new_pool_size
);
1556 btrfs_workqueue_set_max(fs_info
->readahead_workers
, new_pool_size
);
1557 btrfs_workqueue_set_max(fs_info
->scrub_wr_completion_workers
,
1561 static inline void btrfs_remount_prepare(struct btrfs_fs_info
*fs_info
)
1563 set_bit(BTRFS_FS_STATE_REMOUNTING
, &fs_info
->fs_state
);
1566 static inline void btrfs_remount_begin(struct btrfs_fs_info
*fs_info
,
1567 unsigned long old_opts
, int flags
)
1569 if (btrfs_raw_test_opt(old_opts
, AUTO_DEFRAG
) &&
1570 (!btrfs_raw_test_opt(fs_info
->mount_opt
, AUTO_DEFRAG
) ||
1571 (flags
& MS_RDONLY
))) {
1572 /* wait for any defraggers to finish */
1573 wait_event(fs_info
->transaction_wait
,
1574 (atomic_read(&fs_info
->defrag_running
) == 0));
1575 if (flags
& MS_RDONLY
)
1576 sync_filesystem(fs_info
->sb
);
1580 static inline void btrfs_remount_cleanup(struct btrfs_fs_info
*fs_info
,
1581 unsigned long old_opts
)
1584 * We need cleanup all defragable inodes if the autodefragment is
1585 * close or the fs is R/O.
1587 if (btrfs_raw_test_opt(old_opts
, AUTO_DEFRAG
) &&
1588 (!btrfs_raw_test_opt(fs_info
->mount_opt
, AUTO_DEFRAG
) ||
1589 (fs_info
->sb
->s_flags
& MS_RDONLY
))) {
1590 btrfs_cleanup_defrag_inodes(fs_info
);
1593 clear_bit(BTRFS_FS_STATE_REMOUNTING
, &fs_info
->fs_state
);
1596 static int btrfs_remount(struct super_block
*sb
, int *flags
, char *data
)
1598 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
1599 struct btrfs_root
*root
= fs_info
->tree_root
;
1600 unsigned old_flags
= sb
->s_flags
;
1601 unsigned long old_opts
= fs_info
->mount_opt
;
1602 unsigned long old_compress_type
= fs_info
->compress_type
;
1603 u64 old_max_inline
= fs_info
->max_inline
;
1604 u64 old_alloc_start
= fs_info
->alloc_start
;
1605 int old_thread_pool_size
= fs_info
->thread_pool_size
;
1606 unsigned int old_metadata_ratio
= fs_info
->metadata_ratio
;
1609 sync_filesystem(sb
);
1610 btrfs_remount_prepare(fs_info
);
1613 struct security_mnt_opts new_sec_opts
;
1615 security_init_mnt_opts(&new_sec_opts
);
1616 ret
= parse_security_options(data
, &new_sec_opts
);
1619 ret
= setup_security_options(fs_info
, sb
,
1622 security_free_mnt_opts(&new_sec_opts
);
1627 ret
= btrfs_parse_options(root
, data
);
1633 btrfs_remount_begin(fs_info
, old_opts
, *flags
);
1634 btrfs_resize_thread_pool(fs_info
,
1635 fs_info
->thread_pool_size
, old_thread_pool_size
);
1637 if ((*flags
& MS_RDONLY
) == (sb
->s_flags
& MS_RDONLY
))
1640 if (*flags
& MS_RDONLY
) {
1642 * this also happens on 'umount -rf' or on shutdown, when
1643 * the filesystem is busy.
1645 cancel_work_sync(&fs_info
->async_reclaim_work
);
1647 /* wait for the uuid_scan task to finish */
1648 down(&fs_info
->uuid_tree_rescan_sem
);
1649 /* avoid complains from lockdep et al. */
1650 up(&fs_info
->uuid_tree_rescan_sem
);
1652 sb
->s_flags
|= MS_RDONLY
;
1655 * Setting MS_RDONLY will put the cleaner thread to
1656 * sleep at the next loop if it's already active.
1657 * If it's already asleep, we'll leave unused block
1658 * groups on disk until we're mounted read-write again
1659 * unless we clean them up here.
1661 btrfs_delete_unused_bgs(fs_info
);
1663 btrfs_dev_replace_suspend_for_unmount(fs_info
);
1664 btrfs_scrub_cancel(fs_info
);
1665 btrfs_pause_balance(fs_info
);
1667 ret
= btrfs_commit_super(root
);
1671 if (test_bit(BTRFS_FS_STATE_ERROR
, &root
->fs_info
->fs_state
)) {
1673 "Remounting read-write after error is not allowed");
1677 if (fs_info
->fs_devices
->rw_devices
== 0) {
1682 if (fs_info
->fs_devices
->missing_devices
>
1683 fs_info
->num_tolerated_disk_barrier_failures
&&
1684 !(*flags
& MS_RDONLY
)) {
1686 "too many missing devices, writeable remount is not allowed");
1691 if (btrfs_super_log_root(fs_info
->super_copy
) != 0) {
1696 ret
= btrfs_cleanup_fs_roots(fs_info
);
1700 /* recover relocation */
1701 mutex_lock(&fs_info
->cleaner_mutex
);
1702 ret
= btrfs_recover_relocation(root
);
1703 mutex_unlock(&fs_info
->cleaner_mutex
);
1707 ret
= btrfs_resume_balance_async(fs_info
);
1711 ret
= btrfs_resume_dev_replace_async(fs_info
);
1713 btrfs_warn(fs_info
, "failed to resume dev_replace");
1717 if (!fs_info
->uuid_root
) {
1718 btrfs_info(fs_info
, "creating UUID tree");
1719 ret
= btrfs_create_uuid_tree(fs_info
);
1721 btrfs_warn(fs_info
, "failed to create the UUID tree %d", ret
);
1725 sb
->s_flags
&= ~MS_RDONLY
;
1728 wake_up_process(fs_info
->transaction_kthread
);
1729 btrfs_remount_cleanup(fs_info
, old_opts
);
1733 /* We've hit an error - don't reset MS_RDONLY */
1734 if (sb
->s_flags
& MS_RDONLY
)
1735 old_flags
|= MS_RDONLY
;
1736 sb
->s_flags
= old_flags
;
1737 fs_info
->mount_opt
= old_opts
;
1738 fs_info
->compress_type
= old_compress_type
;
1739 fs_info
->max_inline
= old_max_inline
;
1740 mutex_lock(&fs_info
->chunk_mutex
);
1741 fs_info
->alloc_start
= old_alloc_start
;
1742 mutex_unlock(&fs_info
->chunk_mutex
);
1743 btrfs_resize_thread_pool(fs_info
,
1744 old_thread_pool_size
, fs_info
->thread_pool_size
);
1745 fs_info
->metadata_ratio
= old_metadata_ratio
;
1746 btrfs_remount_cleanup(fs_info
, old_opts
);
1750 /* Used to sort the devices by max_avail(descending sort) */
1751 static int btrfs_cmp_device_free_bytes(const void *dev_info1
,
1752 const void *dev_info2
)
1754 if (((struct btrfs_device_info
*)dev_info1
)->max_avail
>
1755 ((struct btrfs_device_info
*)dev_info2
)->max_avail
)
1757 else if (((struct btrfs_device_info
*)dev_info1
)->max_avail
<
1758 ((struct btrfs_device_info
*)dev_info2
)->max_avail
)
1765 * sort the devices by max_avail, in which max free extent size of each device
1766 * is stored.(Descending Sort)
1768 static inline void btrfs_descending_sort_devices(
1769 struct btrfs_device_info
*devices
,
1772 sort(devices
, nr_devices
, sizeof(struct btrfs_device_info
),
1773 btrfs_cmp_device_free_bytes
, NULL
);
1777 * The helper to calc the free space on the devices that can be used to store
1780 static int btrfs_calc_avail_data_space(struct btrfs_root
*root
, u64
*free_bytes
)
1782 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1783 struct btrfs_device_info
*devices_info
;
1784 struct btrfs_fs_devices
*fs_devices
= fs_info
->fs_devices
;
1785 struct btrfs_device
*device
;
1790 u64 min_stripe_size
;
1791 int min_stripes
= 1, num_stripes
= 1;
1792 int i
= 0, nr_devices
;
1796 * We aren't under the device list lock, so this is racey-ish, but good
1797 * enough for our purposes.
1799 nr_devices
= fs_info
->fs_devices
->open_devices
;
1802 nr_devices
= fs_info
->fs_devices
->open_devices
;
1810 devices_info
= kmalloc_array(nr_devices
, sizeof(*devices_info
),
1815 /* calc min stripe number for data space alloction */
1816 type
= btrfs_get_alloc_profile(root
, 1);
1817 if (type
& BTRFS_BLOCK_GROUP_RAID0
) {
1819 num_stripes
= nr_devices
;
1820 } else if (type
& BTRFS_BLOCK_GROUP_RAID1
) {
1823 } else if (type
& BTRFS_BLOCK_GROUP_RAID10
) {
1828 if (type
& BTRFS_BLOCK_GROUP_DUP
)
1829 min_stripe_size
= 2 * BTRFS_STRIPE_LEN
;
1831 min_stripe_size
= BTRFS_STRIPE_LEN
;
1833 if (fs_info
->alloc_start
)
1834 mutex_lock(&fs_devices
->device_list_mutex
);
1836 list_for_each_entry_rcu(device
, &fs_devices
->devices
, dev_list
) {
1837 if (!device
->in_fs_metadata
|| !device
->bdev
||
1838 device
->is_tgtdev_for_dev_replace
)
1841 if (i
>= nr_devices
)
1844 avail_space
= device
->total_bytes
- device
->bytes_used
;
1846 /* align with stripe_len */
1847 avail_space
= div_u64(avail_space
, BTRFS_STRIPE_LEN
);
1848 avail_space
*= BTRFS_STRIPE_LEN
;
1851 * In order to avoid overwritting the superblock on the drive,
1852 * btrfs starts at an offset of at least 1MB when doing chunk
1855 skip_space
= 1024 * 1024;
1857 /* user can set the offset in fs_info->alloc_start. */
1858 if (fs_info
->alloc_start
&&
1859 fs_info
->alloc_start
+ BTRFS_STRIPE_LEN
<=
1860 device
->total_bytes
) {
1862 skip_space
= max(fs_info
->alloc_start
, skip_space
);
1865 * btrfs can not use the free space in
1866 * [0, skip_space - 1], we must subtract it from the
1867 * total. In order to implement it, we account the used
1868 * space in this range first.
1870 ret
= btrfs_account_dev_extents_size(device
, 0,
1874 kfree(devices_info
);
1875 mutex_unlock(&fs_devices
->device_list_mutex
);
1881 /* calc the free space in [0, skip_space - 1] */
1882 skip_space
-= used_space
;
1886 * we can use the free space in [0, skip_space - 1], subtract
1887 * it from the total.
1889 if (avail_space
&& avail_space
>= skip_space
)
1890 avail_space
-= skip_space
;
1894 if (avail_space
< min_stripe_size
)
1897 devices_info
[i
].dev
= device
;
1898 devices_info
[i
].max_avail
= avail_space
;
1903 if (fs_info
->alloc_start
)
1904 mutex_unlock(&fs_devices
->device_list_mutex
);
1908 btrfs_descending_sort_devices(devices_info
, nr_devices
);
1912 while (nr_devices
>= min_stripes
) {
1913 if (num_stripes
> nr_devices
)
1914 num_stripes
= nr_devices
;
1916 if (devices_info
[i
].max_avail
>= min_stripe_size
) {
1920 avail_space
+= devices_info
[i
].max_avail
* num_stripes
;
1921 alloc_size
= devices_info
[i
].max_avail
;
1922 for (j
= i
+ 1 - num_stripes
; j
<= i
; j
++)
1923 devices_info
[j
].max_avail
-= alloc_size
;
1929 kfree(devices_info
);
1930 *free_bytes
= avail_space
;
1935 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles.
1937 * If there's a redundant raid level at DATA block groups, use the respective
1938 * multiplier to scale the sizes.
1940 * Unused device space usage is based on simulating the chunk allocator
1941 * algorithm that respects the device sizes, order of allocations and the
1942 * 'alloc_start' value, this is a close approximation of the actual use but
1943 * there are other factors that may change the result (like a new metadata
1946 * FIXME: not accurate for mixed block groups, total and free/used are ok,
1947 * available appears slightly larger.
1949 static int btrfs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
1951 struct btrfs_fs_info
*fs_info
= btrfs_sb(dentry
->d_sb
);
1952 struct btrfs_super_block
*disk_super
= fs_info
->super_copy
;
1953 struct list_head
*head
= &fs_info
->space_info
;
1954 struct btrfs_space_info
*found
;
1956 u64 total_free_data
= 0;
1957 int bits
= dentry
->d_sb
->s_blocksize_bits
;
1958 __be32
*fsid
= (__be32
*)fs_info
->fsid
;
1959 unsigned factor
= 1;
1960 struct btrfs_block_rsv
*block_rsv
= &fs_info
->global_block_rsv
;
1964 * holding chunk_muext to avoid allocating new chunks, holding
1965 * device_list_mutex to avoid the device being removed
1968 list_for_each_entry_rcu(found
, head
, list
) {
1969 if (found
->flags
& BTRFS_BLOCK_GROUP_DATA
) {
1972 total_free_data
+= found
->disk_total
- found
->disk_used
;
1974 btrfs_account_ro_block_groups_free_space(found
);
1976 for (i
= 0; i
< BTRFS_NR_RAID_TYPES
; i
++) {
1977 if (!list_empty(&found
->block_groups
[i
])) {
1979 case BTRFS_RAID_DUP
:
1980 case BTRFS_RAID_RAID1
:
1981 case BTRFS_RAID_RAID10
:
1988 total_used
+= found
->disk_used
;
1993 buf
->f_blocks
= div_u64(btrfs_super_total_bytes(disk_super
), factor
);
1994 buf
->f_blocks
>>= bits
;
1995 buf
->f_bfree
= buf
->f_blocks
- (div_u64(total_used
, factor
) >> bits
);
1997 /* Account global block reserve as used, it's in logical size already */
1998 spin_lock(&block_rsv
->lock
);
1999 buf
->f_bfree
-= block_rsv
->size
>> bits
;
2000 spin_unlock(&block_rsv
->lock
);
2002 buf
->f_bavail
= div_u64(total_free_data
, factor
);
2003 ret
= btrfs_calc_avail_data_space(fs_info
->tree_root
, &total_free_data
);
2006 buf
->f_bavail
+= div_u64(total_free_data
, factor
);
2007 buf
->f_bavail
= buf
->f_bavail
>> bits
;
2009 buf
->f_type
= BTRFS_SUPER_MAGIC
;
2010 buf
->f_bsize
= dentry
->d_sb
->s_blocksize
;
2011 buf
->f_namelen
= BTRFS_NAME_LEN
;
2013 /* We treat it as constant endianness (it doesn't matter _which_)
2014 because we want the fsid to come out the same whether mounted
2015 on a big-endian or little-endian host */
2016 buf
->f_fsid
.val
[0] = be32_to_cpu(fsid
[0]) ^ be32_to_cpu(fsid
[2]);
2017 buf
->f_fsid
.val
[1] = be32_to_cpu(fsid
[1]) ^ be32_to_cpu(fsid
[3]);
2018 /* Mask in the root object ID too, to disambiguate subvols */
2019 buf
->f_fsid
.val
[0] ^= BTRFS_I(d_inode(dentry
))->root
->objectid
>> 32;
2020 buf
->f_fsid
.val
[1] ^= BTRFS_I(d_inode(dentry
))->root
->objectid
;
2025 static void btrfs_kill_super(struct super_block
*sb
)
2027 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
2028 kill_anon_super(sb
);
2029 free_fs_info(fs_info
);
2032 static struct file_system_type btrfs_fs_type
= {
2033 .owner
= THIS_MODULE
,
2035 .mount
= btrfs_mount
,
2036 .kill_sb
= btrfs_kill_super
,
2037 .fs_flags
= FS_REQUIRES_DEV
| FS_BINARY_MOUNTDATA
,
2039 MODULE_ALIAS_FS("btrfs");
2041 static int btrfs_control_open(struct inode
*inode
, struct file
*file
)
2044 * The control file's private_data is used to hold the
2045 * transaction when it is started and is used to keep
2046 * track of whether a transaction is already in progress.
2048 file
->private_data
= NULL
;
2053 * used by btrfsctl to scan devices when no FS is mounted
2055 static long btrfs_control_ioctl(struct file
*file
, unsigned int cmd
,
2058 struct btrfs_ioctl_vol_args
*vol
;
2059 struct btrfs_fs_devices
*fs_devices
;
2062 if (!capable(CAP_SYS_ADMIN
))
2065 vol
= memdup_user((void __user
*)arg
, sizeof(*vol
));
2067 return PTR_ERR(vol
);
2070 case BTRFS_IOC_SCAN_DEV
:
2071 ret
= btrfs_scan_one_device(vol
->name
, FMODE_READ
,
2072 &btrfs_fs_type
, &fs_devices
);
2074 case BTRFS_IOC_DEVICES_READY
:
2075 ret
= btrfs_scan_one_device(vol
->name
, FMODE_READ
,
2076 &btrfs_fs_type
, &fs_devices
);
2079 ret
= !(fs_devices
->num_devices
== fs_devices
->total_devices
);
2087 static int btrfs_freeze(struct super_block
*sb
)
2089 struct btrfs_trans_handle
*trans
;
2090 struct btrfs_root
*root
= btrfs_sb(sb
)->tree_root
;
2092 trans
= btrfs_attach_transaction_barrier(root
);
2093 if (IS_ERR(trans
)) {
2094 /* no transaction, don't bother */
2095 if (PTR_ERR(trans
) == -ENOENT
)
2097 return PTR_ERR(trans
);
2099 return btrfs_commit_transaction(trans
, root
);
2102 static int btrfs_show_devname(struct seq_file
*m
, struct dentry
*root
)
2104 struct btrfs_fs_info
*fs_info
= btrfs_sb(root
->d_sb
);
2105 struct btrfs_fs_devices
*cur_devices
;
2106 struct btrfs_device
*dev
, *first_dev
= NULL
;
2107 struct list_head
*head
;
2108 struct rcu_string
*name
;
2110 mutex_lock(&fs_info
->fs_devices
->device_list_mutex
);
2111 cur_devices
= fs_info
->fs_devices
;
2112 while (cur_devices
) {
2113 head
= &cur_devices
->devices
;
2114 list_for_each_entry(dev
, head
, dev_list
) {
2119 if (!first_dev
|| dev
->devid
< first_dev
->devid
)
2122 cur_devices
= cur_devices
->seed
;
2127 name
= rcu_dereference(first_dev
->name
);
2128 seq_escape(m
, name
->str
, " \t\n\\");
2133 mutex_unlock(&fs_info
->fs_devices
->device_list_mutex
);
2137 static const struct super_operations btrfs_super_ops
= {
2138 .drop_inode
= btrfs_drop_inode
,
2139 .evict_inode
= btrfs_evict_inode
,
2140 .put_super
= btrfs_put_super
,
2141 .sync_fs
= btrfs_sync_fs
,
2142 .show_options
= btrfs_show_options
,
2143 .show_devname
= btrfs_show_devname
,
2144 .write_inode
= btrfs_write_inode
,
2145 .alloc_inode
= btrfs_alloc_inode
,
2146 .destroy_inode
= btrfs_destroy_inode
,
2147 .statfs
= btrfs_statfs
,
2148 .remount_fs
= btrfs_remount
,
2149 .freeze_fs
= btrfs_freeze
,
2152 static const struct file_operations btrfs_ctl_fops
= {
2153 .open
= btrfs_control_open
,
2154 .unlocked_ioctl
= btrfs_control_ioctl
,
2155 .compat_ioctl
= btrfs_control_ioctl
,
2156 .owner
= THIS_MODULE
,
2157 .llseek
= noop_llseek
,
2160 static struct miscdevice btrfs_misc
= {
2161 .minor
= BTRFS_MINOR
,
2162 .name
= "btrfs-control",
2163 .fops
= &btrfs_ctl_fops
2166 MODULE_ALIAS_MISCDEV(BTRFS_MINOR
);
2167 MODULE_ALIAS("devname:btrfs-control");
2169 static int btrfs_interface_init(void)
2171 return misc_register(&btrfs_misc
);
2174 static void btrfs_interface_exit(void)
2176 misc_deregister(&btrfs_misc
);
2179 static void btrfs_print_info(void)
2181 printk(KERN_INFO
"Btrfs loaded"
2182 #ifdef CONFIG_BTRFS_DEBUG
2185 #ifdef CONFIG_BTRFS_ASSERT
2188 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2189 ", integrity-checker=on"
2194 static int btrfs_run_sanity_tests(void)
2198 ret
= btrfs_init_test_fs();
2202 ret
= btrfs_test_free_space_cache();
2205 ret
= btrfs_test_extent_buffer_operations();
2208 ret
= btrfs_test_extent_io();
2211 ret
= btrfs_test_inodes();
2214 ret
= btrfs_test_qgroups();
2216 btrfs_destroy_test_fs();
2220 static int __init
init_btrfs_fs(void)
2224 err
= btrfs_hash_init();
2230 err
= btrfs_init_sysfs();
2234 btrfs_init_compress();
2236 err
= btrfs_init_cachep();
2240 err
= extent_io_init();
2244 err
= extent_map_init();
2246 goto free_extent_io
;
2248 err
= ordered_data_init();
2250 goto free_extent_map
;
2252 err
= btrfs_delayed_inode_init();
2254 goto free_ordered_data
;
2256 err
= btrfs_auto_defrag_init();
2258 goto free_delayed_inode
;
2260 err
= btrfs_delayed_ref_init();
2262 goto free_auto_defrag
;
2264 err
= btrfs_prelim_ref_init();
2266 goto free_delayed_ref
;
2268 err
= btrfs_end_io_wq_init();
2270 goto free_prelim_ref
;
2272 err
= btrfs_interface_init();
2274 goto free_end_io_wq
;
2276 btrfs_init_lockdep();
2280 err
= btrfs_run_sanity_tests();
2282 goto unregister_ioctl
;
2284 err
= register_filesystem(&btrfs_fs_type
);
2286 goto unregister_ioctl
;
2291 btrfs_interface_exit();
2293 btrfs_end_io_wq_exit();
2295 btrfs_prelim_ref_exit();
2297 btrfs_delayed_ref_exit();
2299 btrfs_auto_defrag_exit();
2301 btrfs_delayed_inode_exit();
2303 ordered_data_exit();
2309 btrfs_destroy_cachep();
2311 btrfs_exit_compress();
2318 static void __exit
exit_btrfs_fs(void)
2320 btrfs_destroy_cachep();
2321 btrfs_delayed_ref_exit();
2322 btrfs_auto_defrag_exit();
2323 btrfs_delayed_inode_exit();
2324 btrfs_prelim_ref_exit();
2325 ordered_data_exit();
2328 btrfs_interface_exit();
2329 btrfs_end_io_wq_exit();
2330 unregister_filesystem(&btrfs_fs_type
);
2332 btrfs_cleanup_fs_uuids();
2333 btrfs_exit_compress();
2337 late_initcall(init_btrfs_fs
);
2338 module_exit(exit_btrfs_fs
)
2340 MODULE_LICENSE("GPL");