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>
45 #include "delayed-inode.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
51 #include "print-tree.h"
56 #include "compression.h"
57 #include "rcu-string.h"
59 #define CREATE_TRACE_POINTS
60 #include <trace/events/btrfs.h>
62 static const struct super_operations btrfs_super_ops
;
63 static struct file_system_type btrfs_fs_type
;
65 static const char *btrfs_decode_error(struct btrfs_fs_info
*fs_info
, int errno
,
72 errstr
= "IO failure";
75 errstr
= "Out of memory";
78 errstr
= "Readonly filesystem";
81 errstr
= "Object already exists";
85 if (snprintf(nbuf
, 16, "error %d", -errno
) >= 0)
94 static void __save_error_info(struct btrfs_fs_info
*fs_info
)
97 * today we only save the error info into ram. Long term we'll
98 * also send it down to the disk
100 fs_info
->fs_state
= BTRFS_SUPER_FLAG_ERROR
;
103 static void save_error_info(struct btrfs_fs_info
*fs_info
)
105 __save_error_info(fs_info
);
108 /* btrfs handle error by forcing the filesystem readonly */
109 static void btrfs_handle_error(struct btrfs_fs_info
*fs_info
)
111 struct super_block
*sb
= fs_info
->sb
;
113 if (sb
->s_flags
& MS_RDONLY
)
116 if (fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
) {
117 sb
->s_flags
|= MS_RDONLY
;
118 printk(KERN_INFO
"btrfs is forced readonly\n");
120 * Note that a running device replace operation is not
121 * canceled here although there is no way to update
122 * the progress. It would add the risk of a deadlock,
123 * therefore the canceling is ommited. The only penalty
124 * is that some I/O remains active until the procedure
125 * completes. The next time when the filesystem is
126 * mounted writeable again, the device replace
127 * operation continues.
135 * __btrfs_std_error decodes expected errors from the caller and
136 * invokes the approciate error response.
138 void __btrfs_std_error(struct btrfs_fs_info
*fs_info
, const char *function
,
139 unsigned int line
, int errno
, const char *fmt
, ...)
141 struct super_block
*sb
= fs_info
->sb
;
148 * Special case: if the error is EROFS, and we're already
149 * under MS_RDONLY, then it is safe here.
151 if (errno
== -EROFS
&& (sb
->s_flags
& MS_RDONLY
))
154 errstr
= btrfs_decode_error(fs_info
, errno
, nbuf
);
156 struct va_format vaf
= {
161 printk(KERN_CRIT
"BTRFS error (device %s) in %s:%d: %s (%pV)\n",
162 sb
->s_id
, function
, line
, errstr
, &vaf
);
164 printk(KERN_CRIT
"BTRFS error (device %s) in %s:%d: %s\n",
165 sb
->s_id
, function
, line
, errstr
);
168 /* Don't go through full error handling during mount */
169 if (sb
->s_flags
& MS_BORN
) {
170 save_error_info(fs_info
);
171 btrfs_handle_error(fs_info
);
176 static const char * const logtypes
[] = {
187 void btrfs_printk(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", 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.
251 void __btrfs_abort_transaction(struct btrfs_trans_handle
*trans
,
252 struct btrfs_root
*root
, const char *function
,
253 unsigned int line
, int errno
)
255 WARN_ONCE(1, KERN_DEBUG
"btrfs: Transaction aborted\n");
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
) {
263 errstr
= btrfs_decode_error(root
->fs_info
, errno
, nbuf
);
264 btrfs_printk(root
->fs_info
,
265 "%s:%d: Aborting unused transaction(%s).\n",
266 function
, line
, errstr
);
269 trans
->transaction
->aborted
= errno
;
270 __btrfs_std_error(root
->fs_info
, function
, line
, errno
, NULL
);
273 * __btrfs_panic decodes unexpected, fatal errors from the caller,
274 * issues an alert, and either panics or BUGs, depending on mount options.
276 void __btrfs_panic(struct btrfs_fs_info
*fs_info
, const char *function
,
277 unsigned int line
, int errno
, const char *fmt
, ...)
280 char *s_id
= "<unknown>";
282 struct va_format vaf
= { .fmt
= fmt
};
286 s_id
= fs_info
->sb
->s_id
;
291 errstr
= btrfs_decode_error(fs_info
, errno
, nbuf
);
292 if (fs_info
->mount_opt
& BTRFS_MOUNT_PANIC_ON_FATAL_ERROR
)
293 panic(KERN_CRIT
"BTRFS panic (device %s) in %s:%d: %pV (%s)\n",
294 s_id
, function
, line
, &vaf
, errstr
);
296 printk(KERN_CRIT
"BTRFS panic (device %s) in %s:%d: %pV (%s)\n",
297 s_id
, function
, line
, &vaf
, errstr
);
299 /* Caller calls BUG() */
302 static void btrfs_put_super(struct super_block
*sb
)
304 (void)close_ctree(btrfs_sb(sb
)->tree_root
);
305 /* FIXME: need to fix VFS to return error? */
306 /* AV: return it _where_? ->put_super() can be triggered by any number
307 * of async events, up to and including delivery of SIGKILL to the
308 * last process that kept it busy. Or segfault in the aforementioned
309 * process... Whom would you report that to?
314 Opt_degraded
, Opt_subvol
, Opt_subvolid
, Opt_device
, Opt_nodatasum
,
315 Opt_nodatacow
, Opt_max_inline
, Opt_alloc_start
, Opt_nobarrier
, Opt_ssd
,
316 Opt_nossd
, Opt_ssd_spread
, Opt_thread_pool
, Opt_noacl
, Opt_compress
,
317 Opt_compress_type
, Opt_compress_force
, Opt_compress_force_type
,
318 Opt_notreelog
, Opt_ratio
, Opt_flushoncommit
, Opt_discard
,
319 Opt_space_cache
, Opt_clear_cache
, Opt_user_subvol_rm_allowed
,
320 Opt_enospc_debug
, Opt_subvolrootid
, Opt_defrag
, Opt_inode_cache
,
321 Opt_no_space_cache
, Opt_recovery
, Opt_skip_balance
,
322 Opt_check_integrity
, Opt_check_integrity_including_extent_data
,
323 Opt_check_integrity_print_mask
, Opt_fatal_errors
,
327 static match_table_t tokens
= {
328 {Opt_degraded
, "degraded"},
329 {Opt_subvol
, "subvol=%s"},
330 {Opt_subvolid
, "subvolid=%d"},
331 {Opt_device
, "device=%s"},
332 {Opt_nodatasum
, "nodatasum"},
333 {Opt_nodatacow
, "nodatacow"},
334 {Opt_nobarrier
, "nobarrier"},
335 {Opt_max_inline
, "max_inline=%s"},
336 {Opt_alloc_start
, "alloc_start=%s"},
337 {Opt_thread_pool
, "thread_pool=%d"},
338 {Opt_compress
, "compress"},
339 {Opt_compress_type
, "compress=%s"},
340 {Opt_compress_force
, "compress-force"},
341 {Opt_compress_force_type
, "compress-force=%s"},
343 {Opt_ssd_spread
, "ssd_spread"},
344 {Opt_nossd
, "nossd"},
345 {Opt_noacl
, "noacl"},
346 {Opt_notreelog
, "notreelog"},
347 {Opt_flushoncommit
, "flushoncommit"},
348 {Opt_ratio
, "metadata_ratio=%d"},
349 {Opt_discard
, "discard"},
350 {Opt_space_cache
, "space_cache"},
351 {Opt_clear_cache
, "clear_cache"},
352 {Opt_user_subvol_rm_allowed
, "user_subvol_rm_allowed"},
353 {Opt_enospc_debug
, "enospc_debug"},
354 {Opt_subvolrootid
, "subvolrootid=%d"},
355 {Opt_defrag
, "autodefrag"},
356 {Opt_inode_cache
, "inode_cache"},
357 {Opt_no_space_cache
, "nospace_cache"},
358 {Opt_recovery
, "recovery"},
359 {Opt_skip_balance
, "skip_balance"},
360 {Opt_check_integrity
, "check_int"},
361 {Opt_check_integrity_including_extent_data
, "check_int_data"},
362 {Opt_check_integrity_print_mask
, "check_int_print_mask=%d"},
363 {Opt_fatal_errors
, "fatal_errors=%s"},
368 * Regular mount options parser. Everything that is needed only when
369 * reading in a new superblock is parsed here.
370 * XXX JDM: This needs to be cleaned up for remount.
372 int btrfs_parse_options(struct btrfs_root
*root
, char *options
)
374 struct btrfs_fs_info
*info
= root
->fs_info
;
375 substring_t args
[MAX_OPT_ARGS
];
376 char *p
, *num
, *orig
= NULL
;
381 bool compress_force
= false;
383 cache_gen
= btrfs_super_cache_generation(root
->fs_info
->super_copy
);
385 btrfs_set_opt(info
->mount_opt
, SPACE_CACHE
);
391 * strsep changes the string, duplicate it because parse_options
394 options
= kstrdup(options
, GFP_NOFS
);
400 while ((p
= strsep(&options
, ",")) != NULL
) {
405 token
= match_token(p
, tokens
, args
);
408 printk(KERN_INFO
"btrfs: allowing degraded mounts\n");
409 btrfs_set_opt(info
->mount_opt
, DEGRADED
);
413 case Opt_subvolrootid
:
416 * These are parsed by btrfs_parse_early_options
417 * and can be happily ignored here.
421 printk(KERN_INFO
"btrfs: setting nodatasum\n");
422 btrfs_set_opt(info
->mount_opt
, NODATASUM
);
425 if (!btrfs_test_opt(root
, COMPRESS
) ||
426 !btrfs_test_opt(root
, FORCE_COMPRESS
)) {
427 printk(KERN_INFO
"btrfs: setting nodatacow, compression disabled\n");
429 printk(KERN_INFO
"btrfs: setting nodatacow\n");
431 info
->compress_type
= BTRFS_COMPRESS_NONE
;
432 btrfs_clear_opt(info
->mount_opt
, COMPRESS
);
433 btrfs_clear_opt(info
->mount_opt
, FORCE_COMPRESS
);
434 btrfs_set_opt(info
->mount_opt
, NODATACOW
);
435 btrfs_set_opt(info
->mount_opt
, NODATASUM
);
437 case Opt_compress_force
:
438 case Opt_compress_force_type
:
439 compress_force
= true;
441 case Opt_compress_type
:
442 if (token
== Opt_compress
||
443 token
== Opt_compress_force
||
444 strcmp(args
[0].from
, "zlib") == 0) {
445 compress_type
= "zlib";
446 info
->compress_type
= BTRFS_COMPRESS_ZLIB
;
447 btrfs_set_opt(info
->mount_opt
, COMPRESS
);
448 btrfs_clear_opt(info
->mount_opt
, NODATACOW
);
449 btrfs_clear_opt(info
->mount_opt
, NODATASUM
);
450 } else if (strcmp(args
[0].from
, "lzo") == 0) {
451 compress_type
= "lzo";
452 info
->compress_type
= BTRFS_COMPRESS_LZO
;
453 btrfs_set_opt(info
->mount_opt
, COMPRESS
);
454 btrfs_clear_opt(info
->mount_opt
, NODATACOW
);
455 btrfs_clear_opt(info
->mount_opt
, NODATASUM
);
456 btrfs_set_fs_incompat(info
, COMPRESS_LZO
);
457 } else if (strncmp(args
[0].from
, "no", 2) == 0) {
458 compress_type
= "no";
459 info
->compress_type
= BTRFS_COMPRESS_NONE
;
460 btrfs_clear_opt(info
->mount_opt
, COMPRESS
);
461 btrfs_clear_opt(info
->mount_opt
, FORCE_COMPRESS
);
462 compress_force
= false;
468 if (compress_force
) {
469 btrfs_set_opt(info
->mount_opt
, FORCE_COMPRESS
);
470 pr_info("btrfs: force %s compression\n",
473 pr_info("btrfs: use %s compression\n",
477 printk(KERN_INFO
"btrfs: use ssd allocation scheme\n");
478 btrfs_set_opt(info
->mount_opt
, SSD
);
481 printk(KERN_INFO
"btrfs: use spread ssd "
482 "allocation scheme\n");
483 btrfs_set_opt(info
->mount_opt
, SSD
);
484 btrfs_set_opt(info
->mount_opt
, SSD_SPREAD
);
487 printk(KERN_INFO
"btrfs: not using ssd allocation "
489 btrfs_set_opt(info
->mount_opt
, NOSSD
);
490 btrfs_clear_opt(info
->mount_opt
, SSD
);
491 btrfs_clear_opt(info
->mount_opt
, SSD_SPREAD
);
494 printk(KERN_INFO
"btrfs: turning off barriers\n");
495 btrfs_set_opt(info
->mount_opt
, NOBARRIER
);
497 case Opt_thread_pool
:
499 match_int(&args
[0], &intarg
);
501 info
->thread_pool_size
= intarg
;
504 num
= match_strdup(&args
[0]);
506 info
->max_inline
= memparse(num
, NULL
);
509 if (info
->max_inline
) {
510 info
->max_inline
= max_t(u64
,
514 printk(KERN_INFO
"btrfs: max_inline at %llu\n",
515 (unsigned long long)info
->max_inline
);
518 case Opt_alloc_start
:
519 num
= match_strdup(&args
[0]);
521 info
->alloc_start
= memparse(num
, NULL
);
524 "btrfs: allocations start at %llu\n",
525 (unsigned long long)info
->alloc_start
);
529 root
->fs_info
->sb
->s_flags
&= ~MS_POSIXACL
;
532 printk(KERN_INFO
"btrfs: disabling tree log\n");
533 btrfs_set_opt(info
->mount_opt
, NOTREELOG
);
535 case Opt_flushoncommit
:
536 printk(KERN_INFO
"btrfs: turning on flush-on-commit\n");
537 btrfs_set_opt(info
->mount_opt
, FLUSHONCOMMIT
);
541 match_int(&args
[0], &intarg
);
543 info
->metadata_ratio
= intarg
;
544 printk(KERN_INFO
"btrfs: metadata ratio %d\n",
545 info
->metadata_ratio
);
549 btrfs_set_opt(info
->mount_opt
, DISCARD
);
551 case Opt_space_cache
:
552 btrfs_set_opt(info
->mount_opt
, SPACE_CACHE
);
554 case Opt_no_space_cache
:
555 printk(KERN_INFO
"btrfs: disabling disk space caching\n");
556 btrfs_clear_opt(info
->mount_opt
, SPACE_CACHE
);
558 case Opt_inode_cache
:
559 printk(KERN_INFO
"btrfs: enabling inode map caching\n");
560 btrfs_set_opt(info
->mount_opt
, INODE_MAP_CACHE
);
562 case Opt_clear_cache
:
563 printk(KERN_INFO
"btrfs: force clearing of disk cache\n");
564 btrfs_set_opt(info
->mount_opt
, CLEAR_CACHE
);
566 case Opt_user_subvol_rm_allowed
:
567 btrfs_set_opt(info
->mount_opt
, USER_SUBVOL_RM_ALLOWED
);
569 case Opt_enospc_debug
:
570 btrfs_set_opt(info
->mount_opt
, ENOSPC_DEBUG
);
573 printk(KERN_INFO
"btrfs: enabling auto defrag\n");
574 btrfs_set_opt(info
->mount_opt
, AUTO_DEFRAG
);
577 printk(KERN_INFO
"btrfs: enabling auto recovery\n");
578 btrfs_set_opt(info
->mount_opt
, RECOVERY
);
580 case Opt_skip_balance
:
581 btrfs_set_opt(info
->mount_opt
, SKIP_BALANCE
);
583 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
584 case Opt_check_integrity_including_extent_data
:
585 printk(KERN_INFO
"btrfs: enabling check integrity"
586 " including extent data\n");
587 btrfs_set_opt(info
->mount_opt
,
588 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA
);
589 btrfs_set_opt(info
->mount_opt
, CHECK_INTEGRITY
);
591 case Opt_check_integrity
:
592 printk(KERN_INFO
"btrfs: enabling check integrity\n");
593 btrfs_set_opt(info
->mount_opt
, CHECK_INTEGRITY
);
595 case Opt_check_integrity_print_mask
:
597 match_int(&args
[0], &intarg
);
599 info
->check_integrity_print_mask
= intarg
;
600 printk(KERN_INFO
"btrfs:"
601 " check_integrity_print_mask 0x%x\n",
602 info
->check_integrity_print_mask
);
606 case Opt_check_integrity_including_extent_data
:
607 case Opt_check_integrity
:
608 case Opt_check_integrity_print_mask
:
609 printk(KERN_ERR
"btrfs: support for check_integrity*"
610 " not compiled in!\n");
614 case Opt_fatal_errors
:
615 if (strcmp(args
[0].from
, "panic") == 0)
616 btrfs_set_opt(info
->mount_opt
,
617 PANIC_ON_FATAL_ERROR
);
618 else if (strcmp(args
[0].from
, "bug") == 0)
619 btrfs_clear_opt(info
->mount_opt
,
620 PANIC_ON_FATAL_ERROR
);
627 printk(KERN_INFO
"btrfs: unrecognized mount option "
636 if (!ret
&& btrfs_test_opt(root
, SPACE_CACHE
))
637 printk(KERN_INFO
"btrfs: disk space caching is enabled\n");
643 * Parse mount options that are required early in the mount process.
645 * All other options will be parsed on much later in the mount process and
646 * only when we need to allocate a new super block.
648 static int btrfs_parse_early_options(const char *options
, fmode_t flags
,
649 void *holder
, char **subvol_name
, u64
*subvol_objectid
,
650 u64
*subvol_rootid
, struct btrfs_fs_devices
**fs_devices
)
652 substring_t args
[MAX_OPT_ARGS
];
653 char *device_name
, *opts
, *orig
, *p
;
661 * strsep changes the string, duplicate it because parse_options
664 opts
= kstrdup(options
, GFP_KERNEL
);
669 while ((p
= strsep(&opts
, ",")) != NULL
) {
674 token
= match_token(p
, tokens
, args
);
678 *subvol_name
= match_strdup(&args
[0]);
682 error
= match_int(&args
[0], &intarg
);
684 /* we want the original fs_tree */
687 BTRFS_FS_TREE_OBJECTID
;
689 *subvol_objectid
= intarg
;
692 case Opt_subvolrootid
:
694 error
= match_int(&args
[0], &intarg
);
696 /* we want the original fs_tree */
699 BTRFS_FS_TREE_OBJECTID
;
701 *subvol_rootid
= intarg
;
705 device_name
= match_strdup(&args
[0]);
710 error
= btrfs_scan_one_device(device_name
,
711 flags
, holder
, fs_devices
);
726 static struct dentry
*get_default_root(struct super_block
*sb
,
729 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
730 struct btrfs_root
*root
= fs_info
->tree_root
;
731 struct btrfs_root
*new_root
;
732 struct btrfs_dir_item
*di
;
733 struct btrfs_path
*path
;
734 struct btrfs_key location
;
740 * We have a specific subvol we want to mount, just setup location and
741 * go look up the root.
743 if (subvol_objectid
) {
744 location
.objectid
= subvol_objectid
;
745 location
.type
= BTRFS_ROOT_ITEM_KEY
;
746 location
.offset
= (u64
)-1;
750 path
= btrfs_alloc_path();
752 return ERR_PTR(-ENOMEM
);
753 path
->leave_spinning
= 1;
756 * Find the "default" dir item which points to the root item that we
757 * will mount by default if we haven't been given a specific subvolume
760 dir_id
= btrfs_super_root_dir(fs_info
->super_copy
);
761 di
= btrfs_lookup_dir_item(NULL
, root
, path
, dir_id
, "default", 7, 0);
763 btrfs_free_path(path
);
768 * Ok the default dir item isn't there. This is weird since
769 * it's always been there, but don't freak out, just try and
770 * mount to root most subvolume.
772 btrfs_free_path(path
);
773 dir_id
= BTRFS_FIRST_FREE_OBJECTID
;
774 new_root
= fs_info
->fs_root
;
778 btrfs_dir_item_key_to_cpu(path
->nodes
[0], di
, &location
);
779 btrfs_free_path(path
);
782 new_root
= btrfs_read_fs_root_no_name(fs_info
, &location
);
783 if (IS_ERR(new_root
))
784 return ERR_CAST(new_root
);
786 if (btrfs_root_refs(&new_root
->root_item
) == 0)
787 return ERR_PTR(-ENOENT
);
789 dir_id
= btrfs_root_dirid(&new_root
->root_item
);
791 location
.objectid
= dir_id
;
792 location
.type
= BTRFS_INODE_ITEM_KEY
;
795 inode
= btrfs_iget(sb
, &location
, new_root
, &new);
797 return ERR_CAST(inode
);
800 * If we're just mounting the root most subvol put the inode and return
801 * a reference to the dentry. We will have already gotten a reference
802 * to the inode in btrfs_fill_super so we're good to go.
804 if (!new && sb
->s_root
->d_inode
== inode
) {
806 return dget(sb
->s_root
);
809 return d_obtain_alias(inode
);
812 static int btrfs_fill_super(struct super_block
*sb
,
813 struct btrfs_fs_devices
*fs_devices
,
814 void *data
, int silent
)
817 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
818 struct btrfs_key key
;
821 sb
->s_maxbytes
= MAX_LFS_FILESIZE
;
822 sb
->s_magic
= BTRFS_SUPER_MAGIC
;
823 sb
->s_op
= &btrfs_super_ops
;
824 sb
->s_d_op
= &btrfs_dentry_operations
;
825 sb
->s_export_op
= &btrfs_export_ops
;
826 sb
->s_xattr
= btrfs_xattr_handlers
;
828 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
829 sb
->s_flags
|= MS_POSIXACL
;
831 sb
->s_flags
|= MS_I_VERSION
;
832 err
= open_ctree(sb
, fs_devices
, (char *)data
);
834 printk("btrfs: open_ctree failed\n");
838 key
.objectid
= BTRFS_FIRST_FREE_OBJECTID
;
839 key
.type
= BTRFS_INODE_ITEM_KEY
;
841 inode
= btrfs_iget(sb
, &key
, fs_info
->fs_root
, NULL
);
843 err
= PTR_ERR(inode
);
847 sb
->s_root
= d_make_root(inode
);
853 save_mount_options(sb
, data
);
854 cleancache_init_fs(sb
);
855 sb
->s_flags
|= MS_ACTIVE
;
859 close_ctree(fs_info
->tree_root
);
863 int btrfs_sync_fs(struct super_block
*sb
, int wait
)
865 struct btrfs_trans_handle
*trans
;
866 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
867 struct btrfs_root
*root
= fs_info
->tree_root
;
869 trace_btrfs_sync_fs(wait
);
872 filemap_flush(fs_info
->btree_inode
->i_mapping
);
876 btrfs_wait_ordered_extents(root
, 0);
878 trans
= btrfs_attach_transaction(root
);
880 /* no transaction, don't bother */
881 if (PTR_ERR(trans
) == -ENOENT
)
883 return PTR_ERR(trans
);
885 return btrfs_commit_transaction(trans
, root
);
888 static int btrfs_show_options(struct seq_file
*seq
, struct dentry
*dentry
)
890 struct btrfs_fs_info
*info
= btrfs_sb(dentry
->d_sb
);
891 struct btrfs_root
*root
= info
->tree_root
;
894 if (btrfs_test_opt(root
, DEGRADED
))
895 seq_puts(seq
, ",degraded");
896 if (btrfs_test_opt(root
, NODATASUM
))
897 seq_puts(seq
, ",nodatasum");
898 if (btrfs_test_opt(root
, NODATACOW
))
899 seq_puts(seq
, ",nodatacow");
900 if (btrfs_test_opt(root
, NOBARRIER
))
901 seq_puts(seq
, ",nobarrier");
902 if (info
->max_inline
!= 8192 * 1024)
903 seq_printf(seq
, ",max_inline=%llu",
904 (unsigned long long)info
->max_inline
);
905 if (info
->alloc_start
!= 0)
906 seq_printf(seq
, ",alloc_start=%llu",
907 (unsigned long long)info
->alloc_start
);
908 if (info
->thread_pool_size
!= min_t(unsigned long,
909 num_online_cpus() + 2, 8))
910 seq_printf(seq
, ",thread_pool=%d", info
->thread_pool_size
);
911 if (btrfs_test_opt(root
, COMPRESS
)) {
912 if (info
->compress_type
== BTRFS_COMPRESS_ZLIB
)
913 compress_type
= "zlib";
915 compress_type
= "lzo";
916 if (btrfs_test_opt(root
, FORCE_COMPRESS
))
917 seq_printf(seq
, ",compress-force=%s", compress_type
);
919 seq_printf(seq
, ",compress=%s", compress_type
);
921 if (btrfs_test_opt(root
, NOSSD
))
922 seq_puts(seq
, ",nossd");
923 if (btrfs_test_opt(root
, SSD_SPREAD
))
924 seq_puts(seq
, ",ssd_spread");
925 else if (btrfs_test_opt(root
, SSD
))
926 seq_puts(seq
, ",ssd");
927 if (btrfs_test_opt(root
, NOTREELOG
))
928 seq_puts(seq
, ",notreelog");
929 if (btrfs_test_opt(root
, FLUSHONCOMMIT
))
930 seq_puts(seq
, ",flushoncommit");
931 if (btrfs_test_opt(root
, DISCARD
))
932 seq_puts(seq
, ",discard");
933 if (!(root
->fs_info
->sb
->s_flags
& MS_POSIXACL
))
934 seq_puts(seq
, ",noacl");
935 if (btrfs_test_opt(root
, SPACE_CACHE
))
936 seq_puts(seq
, ",space_cache");
938 seq_puts(seq
, ",nospace_cache");
939 if (btrfs_test_opt(root
, CLEAR_CACHE
))
940 seq_puts(seq
, ",clear_cache");
941 if (btrfs_test_opt(root
, USER_SUBVOL_RM_ALLOWED
))
942 seq_puts(seq
, ",user_subvol_rm_allowed");
943 if (btrfs_test_opt(root
, ENOSPC_DEBUG
))
944 seq_puts(seq
, ",enospc_debug");
945 if (btrfs_test_opt(root
, AUTO_DEFRAG
))
946 seq_puts(seq
, ",autodefrag");
947 if (btrfs_test_opt(root
, INODE_MAP_CACHE
))
948 seq_puts(seq
, ",inode_cache");
949 if (btrfs_test_opt(root
, SKIP_BALANCE
))
950 seq_puts(seq
, ",skip_balance");
951 if (btrfs_test_opt(root
, PANIC_ON_FATAL_ERROR
))
952 seq_puts(seq
, ",fatal_errors=panic");
956 static int btrfs_test_super(struct super_block
*s
, void *data
)
958 struct btrfs_fs_info
*p
= data
;
959 struct btrfs_fs_info
*fs_info
= btrfs_sb(s
);
961 return fs_info
->fs_devices
== p
->fs_devices
;
964 static int btrfs_set_super(struct super_block
*s
, void *data
)
966 int err
= set_anon_super(s
, data
);
973 * subvolumes are identified by ino 256
975 static inline int is_subvolume_inode(struct inode
*inode
)
977 if (inode
&& inode
->i_ino
== BTRFS_FIRST_FREE_OBJECTID
)
983 * This will strip out the subvol=%s argument for an argument string and add
984 * subvolid=0 to make sure we get the actual tree root for path walking to the
987 static char *setup_root_args(char *args
)
989 unsigned len
= strlen(args
) + 2 + 1;
990 char *src
, *dst
, *buf
;
993 * We need the same args as before, but with this substitution:
994 * s!subvol=[^,]+!subvolid=0!
996 * Since the replacement string is up to 2 bytes longer than the
997 * original, allocate strlen(args) + 2 + 1 bytes.
1000 src
= strstr(args
, "subvol=");
1001 /* This shouldn't happen, but just in case.. */
1005 buf
= dst
= kmalloc(len
, GFP_NOFS
);
1010 * If the subvol= arg is not at the start of the string,
1011 * copy whatever precedes it into buf.
1016 dst
+= strlen(args
);
1019 strcpy(dst
, "subvolid=0");
1020 dst
+= strlen("subvolid=0");
1023 * If there is a "," after the original subvol=... string,
1024 * copy that suffix into our buffer. Otherwise, we're done.
1026 src
= strchr(src
, ',');
1033 static struct dentry
*mount_subvol(const char *subvol_name
, int flags
,
1034 const char *device_name
, char *data
)
1036 struct dentry
*root
;
1037 struct vfsmount
*mnt
;
1040 newargs
= setup_root_args(data
);
1042 return ERR_PTR(-ENOMEM
);
1043 mnt
= vfs_kern_mount(&btrfs_fs_type
, flags
, device_name
,
1047 return ERR_CAST(mnt
);
1049 root
= mount_subtree(mnt
, subvol_name
);
1051 if (!IS_ERR(root
) && !is_subvolume_inode(root
->d_inode
)) {
1052 struct super_block
*s
= root
->d_sb
;
1054 root
= ERR_PTR(-EINVAL
);
1055 deactivate_locked_super(s
);
1056 printk(KERN_ERR
"btrfs: '%s' is not a valid subvolume\n",
1064 * Find a superblock for the given device / mount point.
1066 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1067 * for multiple device setup. Make sure to keep it in sync.
1069 static struct dentry
*btrfs_mount(struct file_system_type
*fs_type
, int flags
,
1070 const char *device_name
, void *data
)
1072 struct block_device
*bdev
= NULL
;
1073 struct super_block
*s
;
1074 struct dentry
*root
;
1075 struct btrfs_fs_devices
*fs_devices
= NULL
;
1076 struct btrfs_fs_info
*fs_info
= NULL
;
1077 fmode_t mode
= FMODE_READ
;
1078 char *subvol_name
= NULL
;
1079 u64 subvol_objectid
= 0;
1080 u64 subvol_rootid
= 0;
1083 if (!(flags
& MS_RDONLY
))
1084 mode
|= FMODE_WRITE
;
1086 error
= btrfs_parse_early_options(data
, mode
, fs_type
,
1087 &subvol_name
, &subvol_objectid
,
1088 &subvol_rootid
, &fs_devices
);
1091 return ERR_PTR(error
);
1095 root
= mount_subvol(subvol_name
, flags
, device_name
, data
);
1100 error
= btrfs_scan_one_device(device_name
, mode
, fs_type
, &fs_devices
);
1102 return ERR_PTR(error
);
1105 * Setup a dummy root and fs_info for test/set super. This is because
1106 * we don't actually fill this stuff out until open_ctree, but we need
1107 * it for searching for existing supers, so this lets us do that and
1108 * then open_ctree will properly initialize everything later.
1110 fs_info
= kzalloc(sizeof(struct btrfs_fs_info
), GFP_NOFS
);
1112 return ERR_PTR(-ENOMEM
);
1114 fs_info
->fs_devices
= fs_devices
;
1116 fs_info
->super_copy
= kzalloc(BTRFS_SUPER_INFO_SIZE
, GFP_NOFS
);
1117 fs_info
->super_for_commit
= kzalloc(BTRFS_SUPER_INFO_SIZE
, GFP_NOFS
);
1118 if (!fs_info
->super_copy
|| !fs_info
->super_for_commit
) {
1123 error
= btrfs_open_devices(fs_devices
, mode
, fs_type
);
1127 if (!(flags
& MS_RDONLY
) && fs_devices
->rw_devices
== 0) {
1129 goto error_close_devices
;
1132 bdev
= fs_devices
->latest_bdev
;
1133 s
= sget(fs_type
, btrfs_test_super
, btrfs_set_super
, flags
| MS_NOSEC
,
1137 goto error_close_devices
;
1141 btrfs_close_devices(fs_devices
);
1142 free_fs_info(fs_info
);
1143 if ((flags
^ s
->s_flags
) & MS_RDONLY
)
1146 char b
[BDEVNAME_SIZE
];
1148 strlcpy(s
->s_id
, bdevname(bdev
, b
), sizeof(s
->s_id
));
1149 btrfs_sb(s
)->bdev_holder
= fs_type
;
1150 error
= btrfs_fill_super(s
, fs_devices
, data
,
1151 flags
& MS_SILENT
? 1 : 0);
1154 root
= !error
? get_default_root(s
, subvol_objectid
) : ERR_PTR(error
);
1156 deactivate_locked_super(s
);
1160 error_close_devices
:
1161 btrfs_close_devices(fs_devices
);
1163 free_fs_info(fs_info
);
1164 return ERR_PTR(error
);
1167 static void btrfs_set_max_workers(struct btrfs_workers
*workers
, int new_limit
)
1169 spin_lock_irq(&workers
->lock
);
1170 workers
->max_workers
= new_limit
;
1171 spin_unlock_irq(&workers
->lock
);
1174 static void btrfs_resize_thread_pool(struct btrfs_fs_info
*fs_info
,
1175 int new_pool_size
, int old_pool_size
)
1177 if (new_pool_size
== old_pool_size
)
1180 fs_info
->thread_pool_size
= new_pool_size
;
1182 printk(KERN_INFO
"btrfs: resize thread pool %d -> %d\n",
1183 old_pool_size
, new_pool_size
);
1185 btrfs_set_max_workers(&fs_info
->generic_worker
, new_pool_size
);
1186 btrfs_set_max_workers(&fs_info
->workers
, new_pool_size
);
1187 btrfs_set_max_workers(&fs_info
->delalloc_workers
, new_pool_size
);
1188 btrfs_set_max_workers(&fs_info
->submit_workers
, new_pool_size
);
1189 btrfs_set_max_workers(&fs_info
->caching_workers
, new_pool_size
);
1190 btrfs_set_max_workers(&fs_info
->fixup_workers
, new_pool_size
);
1191 btrfs_set_max_workers(&fs_info
->endio_workers
, new_pool_size
);
1192 btrfs_set_max_workers(&fs_info
->endio_meta_workers
, new_pool_size
);
1193 btrfs_set_max_workers(&fs_info
->endio_meta_write_workers
, new_pool_size
);
1194 btrfs_set_max_workers(&fs_info
->endio_write_workers
, new_pool_size
);
1195 btrfs_set_max_workers(&fs_info
->endio_freespace_worker
, new_pool_size
);
1196 btrfs_set_max_workers(&fs_info
->delayed_workers
, new_pool_size
);
1197 btrfs_set_max_workers(&fs_info
->readahead_workers
, new_pool_size
);
1198 btrfs_set_max_workers(&fs_info
->scrub_workers
, new_pool_size
);
1201 static int btrfs_remount(struct super_block
*sb
, int *flags
, char *data
)
1203 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
1204 struct btrfs_root
*root
= fs_info
->tree_root
;
1205 unsigned old_flags
= sb
->s_flags
;
1206 unsigned long old_opts
= fs_info
->mount_opt
;
1207 unsigned long old_compress_type
= fs_info
->compress_type
;
1208 u64 old_max_inline
= fs_info
->max_inline
;
1209 u64 old_alloc_start
= fs_info
->alloc_start
;
1210 int old_thread_pool_size
= fs_info
->thread_pool_size
;
1211 unsigned int old_metadata_ratio
= fs_info
->metadata_ratio
;
1214 ret
= btrfs_parse_options(root
, data
);
1220 btrfs_resize_thread_pool(fs_info
,
1221 fs_info
->thread_pool_size
, old_thread_pool_size
);
1223 if ((*flags
& MS_RDONLY
) == (sb
->s_flags
& MS_RDONLY
))
1226 if (*flags
& MS_RDONLY
) {
1227 sb
->s_flags
|= MS_RDONLY
;
1229 ret
= btrfs_commit_super(root
);
1233 if (fs_info
->fs_devices
->rw_devices
== 0) {
1238 if (fs_info
->fs_devices
->missing_devices
>
1239 fs_info
->num_tolerated_disk_barrier_failures
&&
1240 !(*flags
& MS_RDONLY
)) {
1242 "Btrfs: too many missing devices, writeable remount is not allowed\n");
1247 if (btrfs_super_log_root(fs_info
->super_copy
) != 0) {
1252 ret
= btrfs_cleanup_fs_roots(fs_info
);
1256 /* recover relocation */
1257 ret
= btrfs_recover_relocation(root
);
1261 ret
= btrfs_resume_balance_async(fs_info
);
1265 sb
->s_flags
&= ~MS_RDONLY
;
1271 /* We've hit an error - don't reset MS_RDONLY */
1272 if (sb
->s_flags
& MS_RDONLY
)
1273 old_flags
|= MS_RDONLY
;
1274 sb
->s_flags
= old_flags
;
1275 fs_info
->mount_opt
= old_opts
;
1276 fs_info
->compress_type
= old_compress_type
;
1277 fs_info
->max_inline
= old_max_inline
;
1278 fs_info
->alloc_start
= old_alloc_start
;
1279 btrfs_resize_thread_pool(fs_info
,
1280 old_thread_pool_size
, fs_info
->thread_pool_size
);
1281 fs_info
->metadata_ratio
= old_metadata_ratio
;
1285 /* Used to sort the devices by max_avail(descending sort) */
1286 static int btrfs_cmp_device_free_bytes(const void *dev_info1
,
1287 const void *dev_info2
)
1289 if (((struct btrfs_device_info
*)dev_info1
)->max_avail
>
1290 ((struct btrfs_device_info
*)dev_info2
)->max_avail
)
1292 else if (((struct btrfs_device_info
*)dev_info1
)->max_avail
<
1293 ((struct btrfs_device_info
*)dev_info2
)->max_avail
)
1300 * sort the devices by max_avail, in which max free extent size of each device
1301 * is stored.(Descending Sort)
1303 static inline void btrfs_descending_sort_devices(
1304 struct btrfs_device_info
*devices
,
1307 sort(devices
, nr_devices
, sizeof(struct btrfs_device_info
),
1308 btrfs_cmp_device_free_bytes
, NULL
);
1312 * The helper to calc the free space on the devices that can be used to store
1315 static int btrfs_calc_avail_data_space(struct btrfs_root
*root
, u64
*free_bytes
)
1317 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1318 struct btrfs_device_info
*devices_info
;
1319 struct btrfs_fs_devices
*fs_devices
= fs_info
->fs_devices
;
1320 struct btrfs_device
*device
;
1325 u64 min_stripe_size
;
1326 int min_stripes
= 1, num_stripes
= 1;
1327 int i
= 0, nr_devices
;
1330 nr_devices
= fs_info
->fs_devices
->open_devices
;
1331 BUG_ON(!nr_devices
);
1333 devices_info
= kmalloc(sizeof(*devices_info
) * nr_devices
,
1338 /* calc min stripe number for data space alloction */
1339 type
= btrfs_get_alloc_profile(root
, 1);
1340 if (type
& BTRFS_BLOCK_GROUP_RAID0
) {
1342 num_stripes
= nr_devices
;
1343 } else if (type
& BTRFS_BLOCK_GROUP_RAID1
) {
1346 } else if (type
& BTRFS_BLOCK_GROUP_RAID10
) {
1351 if (type
& BTRFS_BLOCK_GROUP_DUP
)
1352 min_stripe_size
= 2 * BTRFS_STRIPE_LEN
;
1354 min_stripe_size
= BTRFS_STRIPE_LEN
;
1356 list_for_each_entry(device
, &fs_devices
->devices
, dev_list
) {
1357 if (!device
->in_fs_metadata
|| !device
->bdev
||
1358 device
->is_tgtdev_for_dev_replace
)
1361 avail_space
= device
->total_bytes
- device
->bytes_used
;
1363 /* align with stripe_len */
1364 do_div(avail_space
, BTRFS_STRIPE_LEN
);
1365 avail_space
*= BTRFS_STRIPE_LEN
;
1368 * In order to avoid overwritting the superblock on the drive,
1369 * btrfs starts at an offset of at least 1MB when doing chunk
1372 skip_space
= 1024 * 1024;
1374 /* user can set the offset in fs_info->alloc_start. */
1375 if (fs_info
->alloc_start
+ BTRFS_STRIPE_LEN
<=
1376 device
->total_bytes
)
1377 skip_space
= max(fs_info
->alloc_start
, skip_space
);
1380 * btrfs can not use the free space in [0, skip_space - 1],
1381 * we must subtract it from the total. In order to implement
1382 * it, we account the used space in this range first.
1384 ret
= btrfs_account_dev_extents_size(device
, 0, skip_space
- 1,
1387 kfree(devices_info
);
1391 /* calc the free space in [0, skip_space - 1] */
1392 skip_space
-= used_space
;
1395 * we can use the free space in [0, skip_space - 1], subtract
1396 * it from the total.
1398 if (avail_space
&& avail_space
>= skip_space
)
1399 avail_space
-= skip_space
;
1403 if (avail_space
< min_stripe_size
)
1406 devices_info
[i
].dev
= device
;
1407 devices_info
[i
].max_avail
= avail_space
;
1414 btrfs_descending_sort_devices(devices_info
, nr_devices
);
1418 while (nr_devices
>= min_stripes
) {
1419 if (num_stripes
> nr_devices
)
1420 num_stripes
= nr_devices
;
1422 if (devices_info
[i
].max_avail
>= min_stripe_size
) {
1426 avail_space
+= devices_info
[i
].max_avail
* num_stripes
;
1427 alloc_size
= devices_info
[i
].max_avail
;
1428 for (j
= i
+ 1 - num_stripes
; j
<= i
; j
++)
1429 devices_info
[j
].max_avail
-= alloc_size
;
1435 kfree(devices_info
);
1436 *free_bytes
= avail_space
;
1440 static int btrfs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
1442 struct btrfs_fs_info
*fs_info
= btrfs_sb(dentry
->d_sb
);
1443 struct btrfs_super_block
*disk_super
= fs_info
->super_copy
;
1444 struct list_head
*head
= &fs_info
->space_info
;
1445 struct btrfs_space_info
*found
;
1447 u64 total_free_data
= 0;
1448 int bits
= dentry
->d_sb
->s_blocksize_bits
;
1449 __be32
*fsid
= (__be32
*)fs_info
->fsid
;
1452 /* holding chunk_muext to avoid allocating new chunks */
1453 mutex_lock(&fs_info
->chunk_mutex
);
1455 list_for_each_entry_rcu(found
, head
, list
) {
1456 if (found
->flags
& BTRFS_BLOCK_GROUP_DATA
) {
1457 total_free_data
+= found
->disk_total
- found
->disk_used
;
1459 btrfs_account_ro_block_groups_free_space(found
);
1462 total_used
+= found
->disk_used
;
1466 buf
->f_namelen
= BTRFS_NAME_LEN
;
1467 buf
->f_blocks
= btrfs_super_total_bytes(disk_super
) >> bits
;
1468 buf
->f_bfree
= buf
->f_blocks
- (total_used
>> bits
);
1469 buf
->f_bsize
= dentry
->d_sb
->s_blocksize
;
1470 buf
->f_type
= BTRFS_SUPER_MAGIC
;
1471 buf
->f_bavail
= total_free_data
;
1472 ret
= btrfs_calc_avail_data_space(fs_info
->tree_root
, &total_free_data
);
1474 mutex_unlock(&fs_info
->chunk_mutex
);
1477 buf
->f_bavail
+= total_free_data
;
1478 buf
->f_bavail
= buf
->f_bavail
>> bits
;
1479 mutex_unlock(&fs_info
->chunk_mutex
);
1481 /* We treat it as constant endianness (it doesn't matter _which_)
1482 because we want the fsid to come out the same whether mounted
1483 on a big-endian or little-endian host */
1484 buf
->f_fsid
.val
[0] = be32_to_cpu(fsid
[0]) ^ be32_to_cpu(fsid
[2]);
1485 buf
->f_fsid
.val
[1] = be32_to_cpu(fsid
[1]) ^ be32_to_cpu(fsid
[3]);
1486 /* Mask in the root object ID too, to disambiguate subvols */
1487 buf
->f_fsid
.val
[0] ^= BTRFS_I(dentry
->d_inode
)->root
->objectid
>> 32;
1488 buf
->f_fsid
.val
[1] ^= BTRFS_I(dentry
->d_inode
)->root
->objectid
;
1493 static void btrfs_kill_super(struct super_block
*sb
)
1495 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
1496 kill_anon_super(sb
);
1497 free_fs_info(fs_info
);
1500 static struct file_system_type btrfs_fs_type
= {
1501 .owner
= THIS_MODULE
,
1503 .mount
= btrfs_mount
,
1504 .kill_sb
= btrfs_kill_super
,
1505 .fs_flags
= FS_REQUIRES_DEV
,
1509 * used by btrfsctl to scan devices when no FS is mounted
1511 static long btrfs_control_ioctl(struct file
*file
, unsigned int cmd
,
1514 struct btrfs_ioctl_vol_args
*vol
;
1515 struct btrfs_fs_devices
*fs_devices
;
1518 if (!capable(CAP_SYS_ADMIN
))
1521 vol
= memdup_user((void __user
*)arg
, sizeof(*vol
));
1523 return PTR_ERR(vol
);
1526 case BTRFS_IOC_SCAN_DEV
:
1527 ret
= btrfs_scan_one_device(vol
->name
, FMODE_READ
,
1528 &btrfs_fs_type
, &fs_devices
);
1530 case BTRFS_IOC_DEVICES_READY
:
1531 ret
= btrfs_scan_one_device(vol
->name
, FMODE_READ
,
1532 &btrfs_fs_type
, &fs_devices
);
1535 ret
= !(fs_devices
->num_devices
== fs_devices
->total_devices
);
1543 static int btrfs_freeze(struct super_block
*sb
)
1545 struct btrfs_trans_handle
*trans
;
1546 struct btrfs_root
*root
= btrfs_sb(sb
)->tree_root
;
1548 trans
= btrfs_attach_transaction(root
);
1549 if (IS_ERR(trans
)) {
1550 /* no transaction, don't bother */
1551 if (PTR_ERR(trans
) == -ENOENT
)
1553 return PTR_ERR(trans
);
1555 return btrfs_commit_transaction(trans
, root
);
1558 static int btrfs_unfreeze(struct super_block
*sb
)
1563 static int btrfs_show_devname(struct seq_file
*m
, struct dentry
*root
)
1565 struct btrfs_fs_info
*fs_info
= btrfs_sb(root
->d_sb
);
1566 struct btrfs_fs_devices
*cur_devices
;
1567 struct btrfs_device
*dev
, *first_dev
= NULL
;
1568 struct list_head
*head
;
1569 struct rcu_string
*name
;
1571 mutex_lock(&fs_info
->fs_devices
->device_list_mutex
);
1572 cur_devices
= fs_info
->fs_devices
;
1573 while (cur_devices
) {
1574 head
= &cur_devices
->devices
;
1575 list_for_each_entry(dev
, head
, dev_list
) {
1578 if (!first_dev
|| dev
->devid
< first_dev
->devid
)
1581 cur_devices
= cur_devices
->seed
;
1586 name
= rcu_dereference(first_dev
->name
);
1587 seq_escape(m
, name
->str
, " \t\n\\");
1592 mutex_unlock(&fs_info
->fs_devices
->device_list_mutex
);
1596 static const struct super_operations btrfs_super_ops
= {
1597 .drop_inode
= btrfs_drop_inode
,
1598 .evict_inode
= btrfs_evict_inode
,
1599 .put_super
= btrfs_put_super
,
1600 .sync_fs
= btrfs_sync_fs
,
1601 .show_options
= btrfs_show_options
,
1602 .show_devname
= btrfs_show_devname
,
1603 .write_inode
= btrfs_write_inode
,
1604 .alloc_inode
= btrfs_alloc_inode
,
1605 .destroy_inode
= btrfs_destroy_inode
,
1606 .statfs
= btrfs_statfs
,
1607 .remount_fs
= btrfs_remount
,
1608 .freeze_fs
= btrfs_freeze
,
1609 .unfreeze_fs
= btrfs_unfreeze
,
1612 static const struct file_operations btrfs_ctl_fops
= {
1613 .unlocked_ioctl
= btrfs_control_ioctl
,
1614 .compat_ioctl
= btrfs_control_ioctl
,
1615 .owner
= THIS_MODULE
,
1616 .llseek
= noop_llseek
,
1619 static struct miscdevice btrfs_misc
= {
1620 .minor
= BTRFS_MINOR
,
1621 .name
= "btrfs-control",
1622 .fops
= &btrfs_ctl_fops
1625 MODULE_ALIAS_MISCDEV(BTRFS_MINOR
);
1626 MODULE_ALIAS("devname:btrfs-control");
1628 static int btrfs_interface_init(void)
1630 return misc_register(&btrfs_misc
);
1633 static void btrfs_interface_exit(void)
1635 if (misc_deregister(&btrfs_misc
) < 0)
1636 printk(KERN_INFO
"btrfs: misc_deregister failed for control device\n");
1639 static int __init
init_btrfs_fs(void)
1643 err
= btrfs_init_sysfs();
1647 btrfs_init_compress();
1649 err
= btrfs_init_cachep();
1653 err
= extent_io_init();
1657 err
= extent_map_init();
1659 goto free_extent_io
;
1661 err
= ordered_data_init();
1663 goto free_extent_map
;
1665 err
= btrfs_delayed_inode_init();
1667 goto free_ordered_data
;
1669 err
= btrfs_interface_init();
1671 goto free_delayed_inode
;
1673 err
= register_filesystem(&btrfs_fs_type
);
1675 goto unregister_ioctl
;
1677 btrfs_init_lockdep();
1679 printk(KERN_INFO
"%s loaded\n", BTRFS_BUILD_VERSION
);
1683 btrfs_interface_exit();
1685 btrfs_delayed_inode_exit();
1687 ordered_data_exit();
1693 btrfs_destroy_cachep();
1695 btrfs_exit_compress();
1700 static void __exit
exit_btrfs_fs(void)
1702 btrfs_destroy_cachep();
1703 btrfs_delayed_inode_exit();
1704 ordered_data_exit();
1707 btrfs_interface_exit();
1708 unregister_filesystem(&btrfs_fs_type
);
1710 btrfs_cleanup_fs_uuids();
1711 btrfs_exit_compress();
1714 module_init(init_btrfs_fs
)
1715 module_exit(exit_btrfs_fs
)
1717 MODULE_LICENSE("GPL");