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");
119 __btrfs_scrub_cancel(fs_info
);
126 * __btrfs_std_error decodes expected errors from the caller and
127 * invokes the approciate error response.
129 void __btrfs_std_error(struct btrfs_fs_info
*fs_info
, const char *function
,
130 unsigned int line
, int errno
, const char *fmt
, ...)
132 struct super_block
*sb
= fs_info
->sb
;
139 * Special case: if the error is EROFS, and we're already
140 * under MS_RDONLY, then it is safe here.
142 if (errno
== -EROFS
&& (sb
->s_flags
& MS_RDONLY
))
145 errstr
= btrfs_decode_error(fs_info
, errno
, nbuf
);
147 struct va_format vaf
= {
152 printk(KERN_CRIT
"BTRFS error (device %s) in %s:%d: %s (%pV)\n",
153 sb
->s_id
, function
, line
, errstr
, &vaf
);
155 printk(KERN_CRIT
"BTRFS error (device %s) in %s:%d: %s\n",
156 sb
->s_id
, function
, line
, errstr
);
159 /* Don't go through full error handling during mount */
160 if (sb
->s_flags
& MS_BORN
) {
161 save_error_info(fs_info
);
162 btrfs_handle_error(fs_info
);
167 static const char * const logtypes
[] = {
178 void btrfs_printk(struct btrfs_fs_info
*fs_info
, const char *fmt
, ...)
180 struct super_block
*sb
= fs_info
->sb
;
182 struct va_format vaf
;
184 const char *type
= logtypes
[4];
189 kern_level
= printk_get_level(fmt
);
191 size_t size
= printk_skip_level(fmt
) - fmt
;
192 memcpy(lvl
, fmt
, size
);
195 type
= logtypes
[kern_level
- '0'];
202 printk("%sBTRFS %s (device %s): %pV", lvl
, type
, sb
->s_id
, &vaf
);
209 void __btrfs_std_error(struct btrfs_fs_info
*fs_info
, const char *function
,
210 unsigned int line
, int errno
, const char *fmt
, ...)
212 struct super_block
*sb
= fs_info
->sb
;
215 * Special case: if the error is EROFS, and we're already
216 * under MS_RDONLY, then it is safe here.
218 if (errno
== -EROFS
&& (sb
->s_flags
& MS_RDONLY
))
221 /* Don't go through full error handling during mount */
222 if (sb
->s_flags
& MS_BORN
) {
223 save_error_info(fs_info
);
224 btrfs_handle_error(fs_info
);
230 * We only mark the transaction aborted and then set the file system read-only.
231 * This will prevent new transactions from starting or trying to join this
234 * This means that error recovery at the call site is limited to freeing
235 * any local memory allocations and passing the error code up without
236 * further cleanup. The transaction should complete as it normally would
237 * in the call path but will return -EIO.
239 * We'll complete the cleanup in btrfs_end_transaction and
240 * btrfs_commit_transaction.
242 void __btrfs_abort_transaction(struct btrfs_trans_handle
*trans
,
243 struct btrfs_root
*root
, const char *function
,
244 unsigned int line
, int errno
)
246 WARN_ONCE(1, KERN_DEBUG
"btrfs: Transaction aborted");
247 trans
->aborted
= errno
;
248 /* Nothing used. The other threads that have joined this
249 * transaction may be able to continue. */
250 if (!trans
->blocks_used
) {
251 btrfs_printk(root
->fs_info
, "Aborting unused transaction.\n");
254 trans
->transaction
->aborted
= errno
;
255 __btrfs_std_error(root
->fs_info
, function
, line
, errno
, NULL
);
258 * __btrfs_panic decodes unexpected, fatal errors from the caller,
259 * issues an alert, and either panics or BUGs, depending on mount options.
261 void __btrfs_panic(struct btrfs_fs_info
*fs_info
, const char *function
,
262 unsigned int line
, int errno
, const char *fmt
, ...)
265 char *s_id
= "<unknown>";
267 struct va_format vaf
= { .fmt
= fmt
};
271 s_id
= fs_info
->sb
->s_id
;
276 errstr
= btrfs_decode_error(fs_info
, errno
, nbuf
);
277 if (fs_info
->mount_opt
& BTRFS_MOUNT_PANIC_ON_FATAL_ERROR
)
278 panic(KERN_CRIT
"BTRFS panic (device %s) in %s:%d: %pV (%s)\n",
279 s_id
, function
, line
, &vaf
, errstr
);
281 printk(KERN_CRIT
"BTRFS panic (device %s) in %s:%d: %pV (%s)\n",
282 s_id
, function
, line
, &vaf
, errstr
);
284 /* Caller calls BUG() */
287 static void btrfs_put_super(struct super_block
*sb
)
289 (void)close_ctree(btrfs_sb(sb
)->tree_root
);
290 /* FIXME: need to fix VFS to return error? */
291 /* AV: return it _where_? ->put_super() can be triggered by any number
292 * of async events, up to and including delivery of SIGKILL to the
293 * last process that kept it busy. Or segfault in the aforementioned
294 * process... Whom would you report that to?
299 Opt_degraded
, Opt_subvol
, Opt_subvolid
, Opt_device
, Opt_nodatasum
,
300 Opt_nodatacow
, Opt_max_inline
, Opt_alloc_start
, Opt_nobarrier
, Opt_ssd
,
301 Opt_nossd
, Opt_ssd_spread
, Opt_thread_pool
, Opt_noacl
, Opt_compress
,
302 Opt_compress_type
, Opt_compress_force
, Opt_compress_force_type
,
303 Opt_notreelog
, Opt_ratio
, Opt_flushoncommit
, Opt_discard
,
304 Opt_space_cache
, Opt_clear_cache
, Opt_user_subvol_rm_allowed
,
305 Opt_enospc_debug
, Opt_subvolrootid
, Opt_defrag
, Opt_inode_cache
,
306 Opt_no_space_cache
, Opt_recovery
, Opt_skip_balance
,
307 Opt_check_integrity
, Opt_check_integrity_including_extent_data
,
308 Opt_check_integrity_print_mask
, Opt_fatal_errors
,
312 static match_table_t tokens
= {
313 {Opt_degraded
, "degraded"},
314 {Opt_subvol
, "subvol=%s"},
315 {Opt_subvolid
, "subvolid=%d"},
316 {Opt_device
, "device=%s"},
317 {Opt_nodatasum
, "nodatasum"},
318 {Opt_nodatacow
, "nodatacow"},
319 {Opt_nobarrier
, "nobarrier"},
320 {Opt_max_inline
, "max_inline=%s"},
321 {Opt_alloc_start
, "alloc_start=%s"},
322 {Opt_thread_pool
, "thread_pool=%d"},
323 {Opt_compress
, "compress"},
324 {Opt_compress_type
, "compress=%s"},
325 {Opt_compress_force
, "compress-force"},
326 {Opt_compress_force_type
, "compress-force=%s"},
328 {Opt_ssd_spread
, "ssd_spread"},
329 {Opt_nossd
, "nossd"},
330 {Opt_noacl
, "noacl"},
331 {Opt_notreelog
, "notreelog"},
332 {Opt_flushoncommit
, "flushoncommit"},
333 {Opt_ratio
, "metadata_ratio=%d"},
334 {Opt_discard
, "discard"},
335 {Opt_space_cache
, "space_cache"},
336 {Opt_clear_cache
, "clear_cache"},
337 {Opt_user_subvol_rm_allowed
, "user_subvol_rm_allowed"},
338 {Opt_enospc_debug
, "enospc_debug"},
339 {Opt_subvolrootid
, "subvolrootid=%d"},
340 {Opt_defrag
, "autodefrag"},
341 {Opt_inode_cache
, "inode_cache"},
342 {Opt_no_space_cache
, "nospace_cache"},
343 {Opt_recovery
, "recovery"},
344 {Opt_skip_balance
, "skip_balance"},
345 {Opt_check_integrity
, "check_int"},
346 {Opt_check_integrity_including_extent_data
, "check_int_data"},
347 {Opt_check_integrity_print_mask
, "check_int_print_mask=%d"},
348 {Opt_fatal_errors
, "fatal_errors=%s"},
353 * Regular mount options parser. Everything that is needed only when
354 * reading in a new superblock is parsed here.
355 * XXX JDM: This needs to be cleaned up for remount.
357 int btrfs_parse_options(struct btrfs_root
*root
, char *options
)
359 struct btrfs_fs_info
*info
= root
->fs_info
;
360 substring_t args
[MAX_OPT_ARGS
];
361 char *p
, *num
, *orig
= NULL
;
366 bool compress_force
= false;
368 cache_gen
= btrfs_super_cache_generation(root
->fs_info
->super_copy
);
370 btrfs_set_opt(info
->mount_opt
, SPACE_CACHE
);
376 * strsep changes the string, duplicate it because parse_options
379 options
= kstrdup(options
, GFP_NOFS
);
385 while ((p
= strsep(&options
, ",")) != NULL
) {
390 token
= match_token(p
, tokens
, args
);
393 printk(KERN_INFO
"btrfs: allowing degraded mounts\n");
394 btrfs_set_opt(info
->mount_opt
, DEGRADED
);
398 case Opt_subvolrootid
:
401 * These are parsed by btrfs_parse_early_options
402 * and can be happily ignored here.
406 printk(KERN_INFO
"btrfs: setting nodatasum\n");
407 btrfs_set_opt(info
->mount_opt
, NODATASUM
);
410 printk(KERN_INFO
"btrfs: setting nodatacow\n");
411 btrfs_set_opt(info
->mount_opt
, NODATACOW
);
412 btrfs_set_opt(info
->mount_opt
, NODATASUM
);
414 case Opt_compress_force
:
415 case Opt_compress_force_type
:
416 compress_force
= true;
418 case Opt_compress_type
:
419 if (token
== Opt_compress
||
420 token
== Opt_compress_force
||
421 strcmp(args
[0].from
, "zlib") == 0) {
422 compress_type
= "zlib";
423 info
->compress_type
= BTRFS_COMPRESS_ZLIB
;
424 btrfs_set_opt(info
->mount_opt
, COMPRESS
);
425 } else if (strcmp(args
[0].from
, "lzo") == 0) {
426 compress_type
= "lzo";
427 info
->compress_type
= BTRFS_COMPRESS_LZO
;
428 btrfs_set_opt(info
->mount_opt
, COMPRESS
);
429 btrfs_set_fs_incompat(info
, COMPRESS_LZO
);
430 } else if (strncmp(args
[0].from
, "no", 2) == 0) {
431 compress_type
= "no";
432 info
->compress_type
= BTRFS_COMPRESS_NONE
;
433 btrfs_clear_opt(info
->mount_opt
, COMPRESS
);
434 btrfs_clear_opt(info
->mount_opt
, FORCE_COMPRESS
);
435 compress_force
= false;
441 if (compress_force
) {
442 btrfs_set_opt(info
->mount_opt
, FORCE_COMPRESS
);
443 pr_info("btrfs: force %s compression\n",
446 pr_info("btrfs: use %s compression\n",
450 printk(KERN_INFO
"btrfs: use ssd allocation scheme\n");
451 btrfs_set_opt(info
->mount_opt
, SSD
);
454 printk(KERN_INFO
"btrfs: use spread ssd "
455 "allocation scheme\n");
456 btrfs_set_opt(info
->mount_opt
, SSD
);
457 btrfs_set_opt(info
->mount_opt
, SSD_SPREAD
);
460 printk(KERN_INFO
"btrfs: not using ssd allocation "
462 btrfs_set_opt(info
->mount_opt
, NOSSD
);
463 btrfs_clear_opt(info
->mount_opt
, SSD
);
464 btrfs_clear_opt(info
->mount_opt
, SSD_SPREAD
);
467 printk(KERN_INFO
"btrfs: turning off barriers\n");
468 btrfs_set_opt(info
->mount_opt
, NOBARRIER
);
470 case Opt_thread_pool
:
472 match_int(&args
[0], &intarg
);
474 info
->thread_pool_size
= intarg
;
477 num
= match_strdup(&args
[0]);
479 info
->max_inline
= memparse(num
, NULL
);
482 if (info
->max_inline
) {
483 info
->max_inline
= max_t(u64
,
487 printk(KERN_INFO
"btrfs: max_inline at %llu\n",
488 (unsigned long long)info
->max_inline
);
491 case Opt_alloc_start
:
492 num
= match_strdup(&args
[0]);
494 info
->alloc_start
= memparse(num
, NULL
);
497 "btrfs: allocations start at %llu\n",
498 (unsigned long long)info
->alloc_start
);
502 root
->fs_info
->sb
->s_flags
&= ~MS_POSIXACL
;
505 printk(KERN_INFO
"btrfs: disabling tree log\n");
506 btrfs_set_opt(info
->mount_opt
, NOTREELOG
);
508 case Opt_flushoncommit
:
509 printk(KERN_INFO
"btrfs: turning on flush-on-commit\n");
510 btrfs_set_opt(info
->mount_opt
, FLUSHONCOMMIT
);
514 match_int(&args
[0], &intarg
);
516 info
->metadata_ratio
= intarg
;
517 printk(KERN_INFO
"btrfs: metadata ratio %d\n",
518 info
->metadata_ratio
);
522 btrfs_set_opt(info
->mount_opt
, DISCARD
);
524 case Opt_space_cache
:
525 btrfs_set_opt(info
->mount_opt
, SPACE_CACHE
);
527 case Opt_no_space_cache
:
528 printk(KERN_INFO
"btrfs: disabling disk space caching\n");
529 btrfs_clear_opt(info
->mount_opt
, SPACE_CACHE
);
531 case Opt_inode_cache
:
532 printk(KERN_INFO
"btrfs: enabling inode map caching\n");
533 btrfs_set_opt(info
->mount_opt
, INODE_MAP_CACHE
);
535 case Opt_clear_cache
:
536 printk(KERN_INFO
"btrfs: force clearing of disk cache\n");
537 btrfs_set_opt(info
->mount_opt
, CLEAR_CACHE
);
539 case Opt_user_subvol_rm_allowed
:
540 btrfs_set_opt(info
->mount_opt
, USER_SUBVOL_RM_ALLOWED
);
542 case Opt_enospc_debug
:
543 btrfs_set_opt(info
->mount_opt
, ENOSPC_DEBUG
);
546 printk(KERN_INFO
"btrfs: enabling auto defrag");
547 btrfs_set_opt(info
->mount_opt
, AUTO_DEFRAG
);
550 printk(KERN_INFO
"btrfs: enabling auto recovery");
551 btrfs_set_opt(info
->mount_opt
, RECOVERY
);
553 case Opt_skip_balance
:
554 btrfs_set_opt(info
->mount_opt
, SKIP_BALANCE
);
556 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
557 case Opt_check_integrity_including_extent_data
:
558 printk(KERN_INFO
"btrfs: enabling check integrity"
559 " including extent data\n");
560 btrfs_set_opt(info
->mount_opt
,
561 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA
);
562 btrfs_set_opt(info
->mount_opt
, CHECK_INTEGRITY
);
564 case Opt_check_integrity
:
565 printk(KERN_INFO
"btrfs: enabling check integrity\n");
566 btrfs_set_opt(info
->mount_opt
, CHECK_INTEGRITY
);
568 case Opt_check_integrity_print_mask
:
570 match_int(&args
[0], &intarg
);
572 info
->check_integrity_print_mask
= intarg
;
573 printk(KERN_INFO
"btrfs:"
574 " check_integrity_print_mask 0x%x\n",
575 info
->check_integrity_print_mask
);
579 case Opt_check_integrity_including_extent_data
:
580 case Opt_check_integrity
:
581 case Opt_check_integrity_print_mask
:
582 printk(KERN_ERR
"btrfs: support for check_integrity*"
583 " not compiled in!\n");
587 case Opt_fatal_errors
:
588 if (strcmp(args
[0].from
, "panic") == 0)
589 btrfs_set_opt(info
->mount_opt
,
590 PANIC_ON_FATAL_ERROR
);
591 else if (strcmp(args
[0].from
, "bug") == 0)
592 btrfs_clear_opt(info
->mount_opt
,
593 PANIC_ON_FATAL_ERROR
);
600 printk(KERN_INFO
"btrfs: unrecognized mount option "
609 if (!ret
&& btrfs_test_opt(root
, SPACE_CACHE
))
610 printk(KERN_INFO
"btrfs: disk space caching is enabled\n");
616 * Parse mount options that are required early in the mount process.
618 * All other options will be parsed on much later in the mount process and
619 * only when we need to allocate a new super block.
621 static int btrfs_parse_early_options(const char *options
, fmode_t flags
,
622 void *holder
, char **subvol_name
, u64
*subvol_objectid
,
623 u64
*subvol_rootid
, struct btrfs_fs_devices
**fs_devices
)
625 substring_t args
[MAX_OPT_ARGS
];
626 char *device_name
, *opts
, *orig
, *p
;
634 * strsep changes the string, duplicate it because parse_options
637 opts
= kstrdup(options
, GFP_KERNEL
);
642 while ((p
= strsep(&opts
, ",")) != NULL
) {
647 token
= match_token(p
, tokens
, args
);
651 *subvol_name
= match_strdup(&args
[0]);
655 error
= match_int(&args
[0], &intarg
);
657 /* we want the original fs_tree */
660 BTRFS_FS_TREE_OBJECTID
;
662 *subvol_objectid
= intarg
;
665 case Opt_subvolrootid
:
667 error
= match_int(&args
[0], &intarg
);
669 /* we want the original fs_tree */
672 BTRFS_FS_TREE_OBJECTID
;
674 *subvol_rootid
= intarg
;
678 device_name
= match_strdup(&args
[0]);
683 error
= btrfs_scan_one_device(device_name
,
684 flags
, holder
, fs_devices
);
699 static struct dentry
*get_default_root(struct super_block
*sb
,
702 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
703 struct btrfs_root
*root
= fs_info
->tree_root
;
704 struct btrfs_root
*new_root
;
705 struct btrfs_dir_item
*di
;
706 struct btrfs_path
*path
;
707 struct btrfs_key location
;
713 * We have a specific subvol we want to mount, just setup location and
714 * go look up the root.
716 if (subvol_objectid
) {
717 location
.objectid
= subvol_objectid
;
718 location
.type
= BTRFS_ROOT_ITEM_KEY
;
719 location
.offset
= (u64
)-1;
723 path
= btrfs_alloc_path();
725 return ERR_PTR(-ENOMEM
);
726 path
->leave_spinning
= 1;
729 * Find the "default" dir item which points to the root item that we
730 * will mount by default if we haven't been given a specific subvolume
733 dir_id
= btrfs_super_root_dir(fs_info
->super_copy
);
734 di
= btrfs_lookup_dir_item(NULL
, root
, path
, dir_id
, "default", 7, 0);
736 btrfs_free_path(path
);
741 * Ok the default dir item isn't there. This is weird since
742 * it's always been there, but don't freak out, just try and
743 * mount to root most subvolume.
745 btrfs_free_path(path
);
746 dir_id
= BTRFS_FIRST_FREE_OBJECTID
;
747 new_root
= fs_info
->fs_root
;
751 btrfs_dir_item_key_to_cpu(path
->nodes
[0], di
, &location
);
752 btrfs_free_path(path
);
755 new_root
= btrfs_read_fs_root_no_name(fs_info
, &location
);
756 if (IS_ERR(new_root
))
757 return ERR_CAST(new_root
);
759 if (btrfs_root_refs(&new_root
->root_item
) == 0)
760 return ERR_PTR(-ENOENT
);
762 dir_id
= btrfs_root_dirid(&new_root
->root_item
);
764 location
.objectid
= dir_id
;
765 location
.type
= BTRFS_INODE_ITEM_KEY
;
768 inode
= btrfs_iget(sb
, &location
, new_root
, &new);
770 return ERR_CAST(inode
);
773 * If we're just mounting the root most subvol put the inode and return
774 * a reference to the dentry. We will have already gotten a reference
775 * to the inode in btrfs_fill_super so we're good to go.
777 if (!new && sb
->s_root
->d_inode
== inode
) {
779 return dget(sb
->s_root
);
782 return d_obtain_alias(inode
);
785 static int btrfs_fill_super(struct super_block
*sb
,
786 struct btrfs_fs_devices
*fs_devices
,
787 void *data
, int silent
)
790 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
791 struct btrfs_key key
;
794 sb
->s_maxbytes
= MAX_LFS_FILESIZE
;
795 sb
->s_magic
= BTRFS_SUPER_MAGIC
;
796 sb
->s_op
= &btrfs_super_ops
;
797 sb
->s_d_op
= &btrfs_dentry_operations
;
798 sb
->s_export_op
= &btrfs_export_ops
;
799 sb
->s_xattr
= btrfs_xattr_handlers
;
801 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
802 sb
->s_flags
|= MS_POSIXACL
;
804 sb
->s_flags
|= MS_I_VERSION
;
805 err
= open_ctree(sb
, fs_devices
, (char *)data
);
807 printk("btrfs: open_ctree failed\n");
811 key
.objectid
= BTRFS_FIRST_FREE_OBJECTID
;
812 key
.type
= BTRFS_INODE_ITEM_KEY
;
814 inode
= btrfs_iget(sb
, &key
, fs_info
->fs_root
, NULL
);
816 err
= PTR_ERR(inode
);
820 sb
->s_root
= d_make_root(inode
);
826 save_mount_options(sb
, data
);
827 cleancache_init_fs(sb
);
828 sb
->s_flags
|= MS_ACTIVE
;
832 close_ctree(fs_info
->tree_root
);
836 int btrfs_sync_fs(struct super_block
*sb
, int wait
)
838 struct btrfs_trans_handle
*trans
;
839 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
840 struct btrfs_root
*root
= fs_info
->tree_root
;
842 trace_btrfs_sync_fs(wait
);
845 filemap_flush(fs_info
->btree_inode
->i_mapping
);
849 btrfs_wait_ordered_extents(root
, 0, 0);
851 spin_lock(&fs_info
->trans_lock
);
852 if (!fs_info
->running_transaction
) {
853 spin_unlock(&fs_info
->trans_lock
);
856 spin_unlock(&fs_info
->trans_lock
);
858 trans
= btrfs_join_transaction(root
);
860 return PTR_ERR(trans
);
861 return btrfs_commit_transaction(trans
, root
);
864 static int btrfs_show_options(struct seq_file
*seq
, struct dentry
*dentry
)
866 struct btrfs_fs_info
*info
= btrfs_sb(dentry
->d_sb
);
867 struct btrfs_root
*root
= info
->tree_root
;
870 if (btrfs_test_opt(root
, DEGRADED
))
871 seq_puts(seq
, ",degraded");
872 if (btrfs_test_opt(root
, NODATASUM
))
873 seq_puts(seq
, ",nodatasum");
874 if (btrfs_test_opt(root
, NODATACOW
))
875 seq_puts(seq
, ",nodatacow");
876 if (btrfs_test_opt(root
, NOBARRIER
))
877 seq_puts(seq
, ",nobarrier");
878 if (info
->max_inline
!= 8192 * 1024)
879 seq_printf(seq
, ",max_inline=%llu",
880 (unsigned long long)info
->max_inline
);
881 if (info
->alloc_start
!= 0)
882 seq_printf(seq
, ",alloc_start=%llu",
883 (unsigned long long)info
->alloc_start
);
884 if (info
->thread_pool_size
!= min_t(unsigned long,
885 num_online_cpus() + 2, 8))
886 seq_printf(seq
, ",thread_pool=%d", info
->thread_pool_size
);
887 if (btrfs_test_opt(root
, COMPRESS
)) {
888 if (info
->compress_type
== BTRFS_COMPRESS_ZLIB
)
889 compress_type
= "zlib";
891 compress_type
= "lzo";
892 if (btrfs_test_opt(root
, FORCE_COMPRESS
))
893 seq_printf(seq
, ",compress-force=%s", compress_type
);
895 seq_printf(seq
, ",compress=%s", compress_type
);
897 if (btrfs_test_opt(root
, NOSSD
))
898 seq_puts(seq
, ",nossd");
899 if (btrfs_test_opt(root
, SSD_SPREAD
))
900 seq_puts(seq
, ",ssd_spread");
901 else if (btrfs_test_opt(root
, SSD
))
902 seq_puts(seq
, ",ssd");
903 if (btrfs_test_opt(root
, NOTREELOG
))
904 seq_puts(seq
, ",notreelog");
905 if (btrfs_test_opt(root
, FLUSHONCOMMIT
))
906 seq_puts(seq
, ",flushoncommit");
907 if (btrfs_test_opt(root
, DISCARD
))
908 seq_puts(seq
, ",discard");
909 if (!(root
->fs_info
->sb
->s_flags
& MS_POSIXACL
))
910 seq_puts(seq
, ",noacl");
911 if (btrfs_test_opt(root
, SPACE_CACHE
))
912 seq_puts(seq
, ",space_cache");
914 seq_puts(seq
, ",nospace_cache");
915 if (btrfs_test_opt(root
, CLEAR_CACHE
))
916 seq_puts(seq
, ",clear_cache");
917 if (btrfs_test_opt(root
, USER_SUBVOL_RM_ALLOWED
))
918 seq_puts(seq
, ",user_subvol_rm_allowed");
919 if (btrfs_test_opt(root
, ENOSPC_DEBUG
))
920 seq_puts(seq
, ",enospc_debug");
921 if (btrfs_test_opt(root
, AUTO_DEFRAG
))
922 seq_puts(seq
, ",autodefrag");
923 if (btrfs_test_opt(root
, INODE_MAP_CACHE
))
924 seq_puts(seq
, ",inode_cache");
925 if (btrfs_test_opt(root
, SKIP_BALANCE
))
926 seq_puts(seq
, ",skip_balance");
927 if (btrfs_test_opt(root
, PANIC_ON_FATAL_ERROR
))
928 seq_puts(seq
, ",fatal_errors=panic");
932 static int btrfs_test_super(struct super_block
*s
, void *data
)
934 struct btrfs_fs_info
*p
= data
;
935 struct btrfs_fs_info
*fs_info
= btrfs_sb(s
);
937 return fs_info
->fs_devices
== p
->fs_devices
;
940 static int btrfs_set_super(struct super_block
*s
, void *data
)
942 int err
= set_anon_super(s
, data
);
949 * subvolumes are identified by ino 256
951 static inline int is_subvolume_inode(struct inode
*inode
)
953 if (inode
&& inode
->i_ino
== BTRFS_FIRST_FREE_OBJECTID
)
959 * This will strip out the subvol=%s argument for an argument string and add
960 * subvolid=0 to make sure we get the actual tree root for path walking to the
963 static char *setup_root_args(char *args
)
965 unsigned len
= strlen(args
) + 2 + 1;
966 char *src
, *dst
, *buf
;
969 * We need the same args as before, but with this substitution:
970 * s!subvol=[^,]+!subvolid=0!
972 * Since the replacement string is up to 2 bytes longer than the
973 * original, allocate strlen(args) + 2 + 1 bytes.
976 src
= strstr(args
, "subvol=");
977 /* This shouldn't happen, but just in case.. */
981 buf
= dst
= kmalloc(len
, GFP_NOFS
);
986 * If the subvol= arg is not at the start of the string,
987 * copy whatever precedes it into buf.
995 strcpy(dst
, "subvolid=0");
996 dst
+= strlen("subvolid=0");
999 * If there is a "," after the original subvol=... string,
1000 * copy that suffix into our buffer. Otherwise, we're done.
1002 src
= strchr(src
, ',');
1009 static struct dentry
*mount_subvol(const char *subvol_name
, int flags
,
1010 const char *device_name
, char *data
)
1012 struct dentry
*root
;
1013 struct vfsmount
*mnt
;
1016 newargs
= setup_root_args(data
);
1018 return ERR_PTR(-ENOMEM
);
1019 mnt
= vfs_kern_mount(&btrfs_fs_type
, flags
, device_name
,
1023 return ERR_CAST(mnt
);
1025 root
= mount_subtree(mnt
, subvol_name
);
1027 if (!IS_ERR(root
) && !is_subvolume_inode(root
->d_inode
)) {
1028 struct super_block
*s
= root
->d_sb
;
1030 root
= ERR_PTR(-EINVAL
);
1031 deactivate_locked_super(s
);
1032 printk(KERN_ERR
"btrfs: '%s' is not a valid subvolume\n",
1040 * Find a superblock for the given device / mount point.
1042 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1043 * for multiple device setup. Make sure to keep it in sync.
1045 static struct dentry
*btrfs_mount(struct file_system_type
*fs_type
, int flags
,
1046 const char *device_name
, void *data
)
1048 struct block_device
*bdev
= NULL
;
1049 struct super_block
*s
;
1050 struct dentry
*root
;
1051 struct btrfs_fs_devices
*fs_devices
= NULL
;
1052 struct btrfs_fs_info
*fs_info
= NULL
;
1053 fmode_t mode
= FMODE_READ
;
1054 char *subvol_name
= NULL
;
1055 u64 subvol_objectid
= 0;
1056 u64 subvol_rootid
= 0;
1059 if (!(flags
& MS_RDONLY
))
1060 mode
|= FMODE_WRITE
;
1062 error
= btrfs_parse_early_options(data
, mode
, fs_type
,
1063 &subvol_name
, &subvol_objectid
,
1064 &subvol_rootid
, &fs_devices
);
1067 return ERR_PTR(error
);
1071 root
= mount_subvol(subvol_name
, flags
, device_name
, data
);
1076 error
= btrfs_scan_one_device(device_name
, mode
, fs_type
, &fs_devices
);
1078 return ERR_PTR(error
);
1081 * Setup a dummy root and fs_info for test/set super. This is because
1082 * we don't actually fill this stuff out until open_ctree, but we need
1083 * it for searching for existing supers, so this lets us do that and
1084 * then open_ctree will properly initialize everything later.
1086 fs_info
= kzalloc(sizeof(struct btrfs_fs_info
), GFP_NOFS
);
1088 return ERR_PTR(-ENOMEM
);
1090 fs_info
->fs_devices
= fs_devices
;
1092 fs_info
->super_copy
= kzalloc(BTRFS_SUPER_INFO_SIZE
, GFP_NOFS
);
1093 fs_info
->super_for_commit
= kzalloc(BTRFS_SUPER_INFO_SIZE
, GFP_NOFS
);
1094 if (!fs_info
->super_copy
|| !fs_info
->super_for_commit
) {
1099 error
= btrfs_open_devices(fs_devices
, mode
, fs_type
);
1103 if (!(flags
& MS_RDONLY
) && fs_devices
->rw_devices
== 0) {
1105 goto error_close_devices
;
1108 bdev
= fs_devices
->latest_bdev
;
1109 s
= sget(fs_type
, btrfs_test_super
, btrfs_set_super
, flags
| MS_NOSEC
,
1113 goto error_close_devices
;
1117 btrfs_close_devices(fs_devices
);
1118 free_fs_info(fs_info
);
1119 if ((flags
^ s
->s_flags
) & MS_RDONLY
)
1122 char b
[BDEVNAME_SIZE
];
1124 strlcpy(s
->s_id
, bdevname(bdev
, b
), sizeof(s
->s_id
));
1125 btrfs_sb(s
)->bdev_holder
= fs_type
;
1126 error
= btrfs_fill_super(s
, fs_devices
, data
,
1127 flags
& MS_SILENT
? 1 : 0);
1130 root
= !error
? get_default_root(s
, subvol_objectid
) : ERR_PTR(error
);
1132 deactivate_locked_super(s
);
1136 error_close_devices
:
1137 btrfs_close_devices(fs_devices
);
1139 free_fs_info(fs_info
);
1140 return ERR_PTR(error
);
1143 static void btrfs_set_max_workers(struct btrfs_workers
*workers
, int new_limit
)
1145 spin_lock_irq(&workers
->lock
);
1146 workers
->max_workers
= new_limit
;
1147 spin_unlock_irq(&workers
->lock
);
1150 static void btrfs_resize_thread_pool(struct btrfs_fs_info
*fs_info
,
1151 int new_pool_size
, int old_pool_size
)
1153 if (new_pool_size
== old_pool_size
)
1156 fs_info
->thread_pool_size
= new_pool_size
;
1158 printk(KERN_INFO
"btrfs: resize thread pool %d -> %d\n",
1159 old_pool_size
, new_pool_size
);
1161 btrfs_set_max_workers(&fs_info
->generic_worker
, new_pool_size
);
1162 btrfs_set_max_workers(&fs_info
->workers
, new_pool_size
);
1163 btrfs_set_max_workers(&fs_info
->delalloc_workers
, new_pool_size
);
1164 btrfs_set_max_workers(&fs_info
->submit_workers
, new_pool_size
);
1165 btrfs_set_max_workers(&fs_info
->caching_workers
, new_pool_size
);
1166 btrfs_set_max_workers(&fs_info
->fixup_workers
, new_pool_size
);
1167 btrfs_set_max_workers(&fs_info
->endio_workers
, new_pool_size
);
1168 btrfs_set_max_workers(&fs_info
->endio_meta_workers
, new_pool_size
);
1169 btrfs_set_max_workers(&fs_info
->endio_meta_write_workers
, new_pool_size
);
1170 btrfs_set_max_workers(&fs_info
->endio_write_workers
, new_pool_size
);
1171 btrfs_set_max_workers(&fs_info
->endio_freespace_worker
, new_pool_size
);
1172 btrfs_set_max_workers(&fs_info
->delayed_workers
, new_pool_size
);
1173 btrfs_set_max_workers(&fs_info
->readahead_workers
, new_pool_size
);
1174 btrfs_set_max_workers(&fs_info
->scrub_workers
, new_pool_size
);
1177 static int btrfs_remount(struct super_block
*sb
, int *flags
, char *data
)
1179 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
1180 struct btrfs_root
*root
= fs_info
->tree_root
;
1181 unsigned old_flags
= sb
->s_flags
;
1182 unsigned long old_opts
= fs_info
->mount_opt
;
1183 unsigned long old_compress_type
= fs_info
->compress_type
;
1184 u64 old_max_inline
= fs_info
->max_inline
;
1185 u64 old_alloc_start
= fs_info
->alloc_start
;
1186 int old_thread_pool_size
= fs_info
->thread_pool_size
;
1187 unsigned int old_metadata_ratio
= fs_info
->metadata_ratio
;
1190 ret
= btrfs_parse_options(root
, data
);
1196 btrfs_resize_thread_pool(fs_info
,
1197 fs_info
->thread_pool_size
, old_thread_pool_size
);
1199 if ((*flags
& MS_RDONLY
) == (sb
->s_flags
& MS_RDONLY
))
1202 if (*flags
& MS_RDONLY
) {
1203 sb
->s_flags
|= MS_RDONLY
;
1205 ret
= btrfs_commit_super(root
);
1209 if (fs_info
->fs_devices
->rw_devices
== 0) {
1214 if (btrfs_super_log_root(fs_info
->super_copy
) != 0) {
1219 ret
= btrfs_cleanup_fs_roots(fs_info
);
1223 /* recover relocation */
1224 ret
= btrfs_recover_relocation(root
);
1228 ret
= btrfs_resume_balance_async(fs_info
);
1232 sb
->s_flags
&= ~MS_RDONLY
;
1238 /* We've hit an error - don't reset MS_RDONLY */
1239 if (sb
->s_flags
& MS_RDONLY
)
1240 old_flags
|= MS_RDONLY
;
1241 sb
->s_flags
= old_flags
;
1242 fs_info
->mount_opt
= old_opts
;
1243 fs_info
->compress_type
= old_compress_type
;
1244 fs_info
->max_inline
= old_max_inline
;
1245 fs_info
->alloc_start
= old_alloc_start
;
1246 btrfs_resize_thread_pool(fs_info
,
1247 old_thread_pool_size
, fs_info
->thread_pool_size
);
1248 fs_info
->metadata_ratio
= old_metadata_ratio
;
1252 /* Used to sort the devices by max_avail(descending sort) */
1253 static int btrfs_cmp_device_free_bytes(const void *dev_info1
,
1254 const void *dev_info2
)
1256 if (((struct btrfs_device_info
*)dev_info1
)->max_avail
>
1257 ((struct btrfs_device_info
*)dev_info2
)->max_avail
)
1259 else if (((struct btrfs_device_info
*)dev_info1
)->max_avail
<
1260 ((struct btrfs_device_info
*)dev_info2
)->max_avail
)
1267 * sort the devices by max_avail, in which max free extent size of each device
1268 * is stored.(Descending Sort)
1270 static inline void btrfs_descending_sort_devices(
1271 struct btrfs_device_info
*devices
,
1274 sort(devices
, nr_devices
, sizeof(struct btrfs_device_info
),
1275 btrfs_cmp_device_free_bytes
, NULL
);
1279 * The helper to calc the free space on the devices that can be used to store
1282 static int btrfs_calc_avail_data_space(struct btrfs_root
*root
, u64
*free_bytes
)
1284 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1285 struct btrfs_device_info
*devices_info
;
1286 struct btrfs_fs_devices
*fs_devices
= fs_info
->fs_devices
;
1287 struct btrfs_device
*device
;
1292 u64 min_stripe_size
;
1293 int min_stripes
= 1, num_stripes
= 1;
1294 int i
= 0, nr_devices
;
1297 nr_devices
= fs_info
->fs_devices
->open_devices
;
1298 BUG_ON(!nr_devices
);
1300 devices_info
= kmalloc(sizeof(*devices_info
) * nr_devices
,
1305 /* calc min stripe number for data space alloction */
1306 type
= btrfs_get_alloc_profile(root
, 1);
1307 if (type
& BTRFS_BLOCK_GROUP_RAID0
) {
1309 num_stripes
= nr_devices
;
1310 } else if (type
& BTRFS_BLOCK_GROUP_RAID1
) {
1313 } else if (type
& BTRFS_BLOCK_GROUP_RAID10
) {
1318 if (type
& BTRFS_BLOCK_GROUP_DUP
)
1319 min_stripe_size
= 2 * BTRFS_STRIPE_LEN
;
1321 min_stripe_size
= BTRFS_STRIPE_LEN
;
1323 list_for_each_entry(device
, &fs_devices
->devices
, dev_list
) {
1324 if (!device
->in_fs_metadata
|| !device
->bdev
)
1327 avail_space
= device
->total_bytes
- device
->bytes_used
;
1329 /* align with stripe_len */
1330 do_div(avail_space
, BTRFS_STRIPE_LEN
);
1331 avail_space
*= BTRFS_STRIPE_LEN
;
1334 * In order to avoid overwritting the superblock on the drive,
1335 * btrfs starts at an offset of at least 1MB when doing chunk
1338 skip_space
= 1024 * 1024;
1340 /* user can set the offset in fs_info->alloc_start. */
1341 if (fs_info
->alloc_start
+ BTRFS_STRIPE_LEN
<=
1342 device
->total_bytes
)
1343 skip_space
= max(fs_info
->alloc_start
, skip_space
);
1346 * btrfs can not use the free space in [0, skip_space - 1],
1347 * we must subtract it from the total. In order to implement
1348 * it, we account the used space in this range first.
1350 ret
= btrfs_account_dev_extents_size(device
, 0, skip_space
- 1,
1353 kfree(devices_info
);
1357 /* calc the free space in [0, skip_space - 1] */
1358 skip_space
-= used_space
;
1361 * we can use the free space in [0, skip_space - 1], subtract
1362 * it from the total.
1364 if (avail_space
&& avail_space
>= skip_space
)
1365 avail_space
-= skip_space
;
1369 if (avail_space
< min_stripe_size
)
1372 devices_info
[i
].dev
= device
;
1373 devices_info
[i
].max_avail
= avail_space
;
1380 btrfs_descending_sort_devices(devices_info
, nr_devices
);
1384 while (nr_devices
>= min_stripes
) {
1385 if (num_stripes
> nr_devices
)
1386 num_stripes
= nr_devices
;
1388 if (devices_info
[i
].max_avail
>= min_stripe_size
) {
1392 avail_space
+= devices_info
[i
].max_avail
* num_stripes
;
1393 alloc_size
= devices_info
[i
].max_avail
;
1394 for (j
= i
+ 1 - num_stripes
; j
<= i
; j
++)
1395 devices_info
[j
].max_avail
-= alloc_size
;
1401 kfree(devices_info
);
1402 *free_bytes
= avail_space
;
1406 static int btrfs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
1408 struct btrfs_fs_info
*fs_info
= btrfs_sb(dentry
->d_sb
);
1409 struct btrfs_super_block
*disk_super
= fs_info
->super_copy
;
1410 struct list_head
*head
= &fs_info
->space_info
;
1411 struct btrfs_space_info
*found
;
1413 u64 total_free_data
= 0;
1414 int bits
= dentry
->d_sb
->s_blocksize_bits
;
1415 __be32
*fsid
= (__be32
*)fs_info
->fsid
;
1418 /* holding chunk_muext to avoid allocating new chunks */
1419 mutex_lock(&fs_info
->chunk_mutex
);
1421 list_for_each_entry_rcu(found
, head
, list
) {
1422 if (found
->flags
& BTRFS_BLOCK_GROUP_DATA
) {
1423 total_free_data
+= found
->disk_total
- found
->disk_used
;
1425 btrfs_account_ro_block_groups_free_space(found
);
1428 total_used
+= found
->disk_used
;
1432 buf
->f_namelen
= BTRFS_NAME_LEN
;
1433 buf
->f_blocks
= btrfs_super_total_bytes(disk_super
) >> bits
;
1434 buf
->f_bfree
= buf
->f_blocks
- (total_used
>> bits
);
1435 buf
->f_bsize
= dentry
->d_sb
->s_blocksize
;
1436 buf
->f_type
= BTRFS_SUPER_MAGIC
;
1437 buf
->f_bavail
= total_free_data
;
1438 ret
= btrfs_calc_avail_data_space(fs_info
->tree_root
, &total_free_data
);
1440 mutex_unlock(&fs_info
->chunk_mutex
);
1443 buf
->f_bavail
+= total_free_data
;
1444 buf
->f_bavail
= buf
->f_bavail
>> bits
;
1445 mutex_unlock(&fs_info
->chunk_mutex
);
1447 /* We treat it as constant endianness (it doesn't matter _which_)
1448 because we want the fsid to come out the same whether mounted
1449 on a big-endian or little-endian host */
1450 buf
->f_fsid
.val
[0] = be32_to_cpu(fsid
[0]) ^ be32_to_cpu(fsid
[2]);
1451 buf
->f_fsid
.val
[1] = be32_to_cpu(fsid
[1]) ^ be32_to_cpu(fsid
[3]);
1452 /* Mask in the root object ID too, to disambiguate subvols */
1453 buf
->f_fsid
.val
[0] ^= BTRFS_I(dentry
->d_inode
)->root
->objectid
>> 32;
1454 buf
->f_fsid
.val
[1] ^= BTRFS_I(dentry
->d_inode
)->root
->objectid
;
1459 static void btrfs_kill_super(struct super_block
*sb
)
1461 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
1462 kill_anon_super(sb
);
1463 free_fs_info(fs_info
);
1466 static struct file_system_type btrfs_fs_type
= {
1467 .owner
= THIS_MODULE
,
1469 .mount
= btrfs_mount
,
1470 .kill_sb
= btrfs_kill_super
,
1471 .fs_flags
= FS_REQUIRES_DEV
,
1475 * used by btrfsctl to scan devices when no FS is mounted
1477 static long btrfs_control_ioctl(struct file
*file
, unsigned int cmd
,
1480 struct btrfs_ioctl_vol_args
*vol
;
1481 struct btrfs_fs_devices
*fs_devices
;
1484 if (!capable(CAP_SYS_ADMIN
))
1487 vol
= memdup_user((void __user
*)arg
, sizeof(*vol
));
1489 return PTR_ERR(vol
);
1492 case BTRFS_IOC_SCAN_DEV
:
1493 ret
= btrfs_scan_one_device(vol
->name
, FMODE_READ
,
1494 &btrfs_fs_type
, &fs_devices
);
1496 case BTRFS_IOC_DEVICES_READY
:
1497 ret
= btrfs_scan_one_device(vol
->name
, FMODE_READ
,
1498 &btrfs_fs_type
, &fs_devices
);
1501 ret
= !(fs_devices
->num_devices
== fs_devices
->total_devices
);
1509 static int btrfs_freeze(struct super_block
*sb
)
1511 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
1512 mutex_lock(&fs_info
->transaction_kthread_mutex
);
1513 mutex_lock(&fs_info
->cleaner_mutex
);
1517 static int btrfs_unfreeze(struct super_block
*sb
)
1519 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
1520 mutex_unlock(&fs_info
->cleaner_mutex
);
1521 mutex_unlock(&fs_info
->transaction_kthread_mutex
);
1525 static int btrfs_show_devname(struct seq_file
*m
, struct dentry
*root
)
1527 struct btrfs_fs_info
*fs_info
= btrfs_sb(root
->d_sb
);
1528 struct btrfs_fs_devices
*cur_devices
;
1529 struct btrfs_device
*dev
, *first_dev
= NULL
;
1530 struct list_head
*head
;
1531 struct rcu_string
*name
;
1533 mutex_lock(&fs_info
->fs_devices
->device_list_mutex
);
1534 cur_devices
= fs_info
->fs_devices
;
1535 while (cur_devices
) {
1536 head
= &cur_devices
->devices
;
1537 list_for_each_entry(dev
, head
, dev_list
) {
1540 if (!first_dev
|| dev
->devid
< first_dev
->devid
)
1543 cur_devices
= cur_devices
->seed
;
1548 name
= rcu_dereference(first_dev
->name
);
1549 seq_escape(m
, name
->str
, " \t\n\\");
1554 mutex_unlock(&fs_info
->fs_devices
->device_list_mutex
);
1558 static const struct super_operations btrfs_super_ops
= {
1559 .drop_inode
= btrfs_drop_inode
,
1560 .evict_inode
= btrfs_evict_inode
,
1561 .put_super
= btrfs_put_super
,
1562 .sync_fs
= btrfs_sync_fs
,
1563 .show_options
= btrfs_show_options
,
1564 .show_devname
= btrfs_show_devname
,
1565 .write_inode
= btrfs_write_inode
,
1566 .alloc_inode
= btrfs_alloc_inode
,
1567 .destroy_inode
= btrfs_destroy_inode
,
1568 .statfs
= btrfs_statfs
,
1569 .remount_fs
= btrfs_remount
,
1570 .freeze_fs
= btrfs_freeze
,
1571 .unfreeze_fs
= btrfs_unfreeze
,
1574 static const struct file_operations btrfs_ctl_fops
= {
1575 .unlocked_ioctl
= btrfs_control_ioctl
,
1576 .compat_ioctl
= btrfs_control_ioctl
,
1577 .owner
= THIS_MODULE
,
1578 .llseek
= noop_llseek
,
1581 static struct miscdevice btrfs_misc
= {
1582 .minor
= BTRFS_MINOR
,
1583 .name
= "btrfs-control",
1584 .fops
= &btrfs_ctl_fops
1587 MODULE_ALIAS_MISCDEV(BTRFS_MINOR
);
1588 MODULE_ALIAS("devname:btrfs-control");
1590 static int btrfs_interface_init(void)
1592 return misc_register(&btrfs_misc
);
1595 static void btrfs_interface_exit(void)
1597 if (misc_deregister(&btrfs_misc
) < 0)
1598 printk(KERN_INFO
"misc_deregister failed for control device");
1601 static int __init
init_btrfs_fs(void)
1605 err
= btrfs_init_sysfs();
1609 btrfs_init_compress();
1611 err
= btrfs_init_cachep();
1615 err
= extent_io_init();
1619 err
= extent_map_init();
1621 goto free_extent_io
;
1623 err
= btrfs_delayed_inode_init();
1625 goto free_extent_map
;
1627 err
= btrfs_interface_init();
1629 goto free_delayed_inode
;
1631 err
= register_filesystem(&btrfs_fs_type
);
1633 goto unregister_ioctl
;
1635 btrfs_init_lockdep();
1637 printk(KERN_INFO
"%s loaded\n", BTRFS_BUILD_VERSION
);
1641 btrfs_interface_exit();
1643 btrfs_delayed_inode_exit();
1649 btrfs_destroy_cachep();
1651 btrfs_exit_compress();
1656 static void __exit
exit_btrfs_fs(void)
1658 btrfs_destroy_cachep();
1659 btrfs_delayed_inode_exit();
1662 btrfs_interface_exit();
1663 unregister_filesystem(&btrfs_fs_type
);
1665 btrfs_cleanup_fs_uuids();
1666 btrfs_exit_compress();
1669 module_init(init_btrfs_fs
)
1670 module_exit(exit_btrfs_fs
)
1672 MODULE_LICENSE("GPL");