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>
45 #include "transaction.h"
46 #include "btrfs_inode.h"
48 #include "print-tree.h"
53 #include "compression.h"
55 static const struct super_operations btrfs_super_ops
;
57 static void btrfs_put_super(struct super_block
*sb
)
59 struct btrfs_root
*root
= btrfs_sb(sb
);
62 ret
= close_ctree(root
);
65 (void)ret
; /* FIXME: need to fix VFS to return error? */
69 Opt_degraded
, Opt_subvol
, Opt_subvolid
, Opt_device
, Opt_nodatasum
,
70 Opt_nodatacow
, Opt_max_inline
, Opt_alloc_start
, Opt_nobarrier
, Opt_ssd
,
71 Opt_nossd
, Opt_ssd_spread
, Opt_thread_pool
, Opt_noacl
, Opt_compress
,
72 Opt_compress_force
, Opt_notreelog
, Opt_ratio
, Opt_flushoncommit
,
73 Opt_discard
, Opt_space_cache
, Opt_clear_cache
, Opt_err
,
74 Opt_user_subvol_rm_allowed
,
77 static match_table_t tokens
= {
78 {Opt_degraded
, "degraded"},
79 {Opt_subvol
, "subvol=%s"},
80 {Opt_subvolid
, "subvolid=%d"},
81 {Opt_device
, "device=%s"},
82 {Opt_nodatasum
, "nodatasum"},
83 {Opt_nodatacow
, "nodatacow"},
84 {Opt_nobarrier
, "nobarrier"},
85 {Opt_max_inline
, "max_inline=%s"},
86 {Opt_alloc_start
, "alloc_start=%s"},
87 {Opt_thread_pool
, "thread_pool=%d"},
88 {Opt_compress
, "compress"},
89 {Opt_compress_force
, "compress-force"},
91 {Opt_ssd_spread
, "ssd_spread"},
94 {Opt_notreelog
, "notreelog"},
95 {Opt_flushoncommit
, "flushoncommit"},
96 {Opt_ratio
, "metadata_ratio=%d"},
97 {Opt_discard
, "discard"},
98 {Opt_space_cache
, "space_cache"},
99 {Opt_clear_cache
, "clear_cache"},
100 {Opt_user_subvol_rm_allowed
, "user_subvol_rm_allowed"},
105 * Regular mount options parser. Everything that is needed only when
106 * reading in a new superblock is parsed here.
108 int btrfs_parse_options(struct btrfs_root
*root
, char *options
)
110 struct btrfs_fs_info
*info
= root
->fs_info
;
111 substring_t args
[MAX_OPT_ARGS
];
112 char *p
, *num
, *orig
;
120 * strsep changes the string, duplicate it because parse_options
123 options
= kstrdup(options
, GFP_NOFS
);
129 while ((p
= strsep(&options
, ",")) != NULL
) {
134 token
= match_token(p
, tokens
, args
);
137 printk(KERN_INFO
"btrfs: allowing degraded mounts\n");
138 btrfs_set_opt(info
->mount_opt
, DEGRADED
);
144 * These are parsed by btrfs_parse_early_options
145 * and can be happily ignored here.
149 printk(KERN_INFO
"btrfs: setting nodatasum\n");
150 btrfs_set_opt(info
->mount_opt
, NODATASUM
);
153 printk(KERN_INFO
"btrfs: setting nodatacow\n");
154 btrfs_set_opt(info
->mount_opt
, NODATACOW
);
155 btrfs_set_opt(info
->mount_opt
, NODATASUM
);
158 printk(KERN_INFO
"btrfs: use compression\n");
159 btrfs_set_opt(info
->mount_opt
, COMPRESS
);
161 case Opt_compress_force
:
162 printk(KERN_INFO
"btrfs: forcing compression\n");
163 btrfs_set_opt(info
->mount_opt
, FORCE_COMPRESS
);
164 btrfs_set_opt(info
->mount_opt
, COMPRESS
);
167 printk(KERN_INFO
"btrfs: use ssd allocation scheme\n");
168 btrfs_set_opt(info
->mount_opt
, SSD
);
171 printk(KERN_INFO
"btrfs: use spread ssd "
172 "allocation scheme\n");
173 btrfs_set_opt(info
->mount_opt
, SSD
);
174 btrfs_set_opt(info
->mount_opt
, SSD_SPREAD
);
177 printk(KERN_INFO
"btrfs: not using ssd allocation "
179 btrfs_set_opt(info
->mount_opt
, NOSSD
);
180 btrfs_clear_opt(info
->mount_opt
, SSD
);
181 btrfs_clear_opt(info
->mount_opt
, SSD_SPREAD
);
184 printk(KERN_INFO
"btrfs: turning off barriers\n");
185 btrfs_set_opt(info
->mount_opt
, NOBARRIER
);
187 case Opt_thread_pool
:
189 match_int(&args
[0], &intarg
);
191 info
->thread_pool_size
= intarg
;
192 printk(KERN_INFO
"btrfs: thread pool %d\n",
193 info
->thread_pool_size
);
197 num
= match_strdup(&args
[0]);
199 info
->max_inline
= memparse(num
, NULL
);
202 if (info
->max_inline
) {
203 info
->max_inline
= max_t(u64
,
207 printk(KERN_INFO
"btrfs: max_inline at %llu\n",
208 (unsigned long long)info
->max_inline
);
211 case Opt_alloc_start
:
212 num
= match_strdup(&args
[0]);
214 info
->alloc_start
= memparse(num
, NULL
);
217 "btrfs: allocations start at %llu\n",
218 (unsigned long long)info
->alloc_start
);
222 root
->fs_info
->sb
->s_flags
&= ~MS_POSIXACL
;
225 printk(KERN_INFO
"btrfs: disabling tree log\n");
226 btrfs_set_opt(info
->mount_opt
, NOTREELOG
);
228 case Opt_flushoncommit
:
229 printk(KERN_INFO
"btrfs: turning on flush-on-commit\n");
230 btrfs_set_opt(info
->mount_opt
, FLUSHONCOMMIT
);
234 match_int(&args
[0], &intarg
);
236 info
->metadata_ratio
= intarg
;
237 printk(KERN_INFO
"btrfs: metadata ratio %d\n",
238 info
->metadata_ratio
);
242 btrfs_set_opt(info
->mount_opt
, DISCARD
);
244 case Opt_space_cache
:
245 printk(KERN_INFO
"btrfs: enabling disk space caching\n");
246 btrfs_set_opt(info
->mount_opt
, SPACE_CACHE
);
247 case Opt_clear_cache
:
248 printk(KERN_INFO
"btrfs: force clearing of disk cache\n");
249 btrfs_set_opt(info
->mount_opt
, CLEAR_CACHE
);
251 case Opt_user_subvol_rm_allowed
:
252 btrfs_set_opt(info
->mount_opt
, USER_SUBVOL_RM_ALLOWED
);
255 printk(KERN_INFO
"btrfs: unrecognized mount option "
269 * Parse mount options that are required early in the mount process.
271 * All other options will be parsed on much later in the mount process and
272 * only when we need to allocate a new super block.
274 static int btrfs_parse_early_options(const char *options
, fmode_t flags
,
275 void *holder
, char **subvol_name
, u64
*subvol_objectid
,
276 struct btrfs_fs_devices
**fs_devices
)
278 substring_t args
[MAX_OPT_ARGS
];
287 * strsep changes the string, duplicate it because parse_options
290 opts
= kstrdup(options
, GFP_KERNEL
);
294 while ((p
= strsep(&opts
, ",")) != NULL
) {
299 token
= match_token(p
, tokens
, args
);
302 *subvol_name
= match_strdup(&args
[0]);
306 error
= match_int(&args
[0], &intarg
);
308 /* we want the original fs_tree */
311 BTRFS_FS_TREE_OBJECTID
;
313 *subvol_objectid
= intarg
;
317 error
= btrfs_scan_one_device(match_strdup(&args
[0]),
318 flags
, holder
, fs_devices
);
331 * If no subvolume name is specified we use the default one. Allocate
332 * a copy of the string "." here so that code later in the
333 * mount path doesn't care if it's the default volume or another one.
336 *subvol_name
= kstrdup(".", GFP_KERNEL
);
343 static struct dentry
*get_default_root(struct super_block
*sb
,
346 struct btrfs_root
*root
= sb
->s_fs_info
;
347 struct btrfs_root
*new_root
;
348 struct btrfs_dir_item
*di
;
349 struct btrfs_path
*path
;
350 struct btrfs_key location
;
352 struct dentry
*dentry
;
357 * We have a specific subvol we want to mount, just setup location and
358 * go look up the root.
360 if (subvol_objectid
) {
361 location
.objectid
= subvol_objectid
;
362 location
.type
= BTRFS_ROOT_ITEM_KEY
;
363 location
.offset
= (u64
)-1;
367 path
= btrfs_alloc_path();
369 return ERR_PTR(-ENOMEM
);
370 path
->leave_spinning
= 1;
373 * Find the "default" dir item which points to the root item that we
374 * will mount by default if we haven't been given a specific subvolume
377 dir_id
= btrfs_super_root_dir(&root
->fs_info
->super_copy
);
378 di
= btrfs_lookup_dir_item(NULL
, root
, path
, dir_id
, "default", 7, 0);
383 * Ok the default dir item isn't there. This is weird since
384 * it's always been there, but don't freak out, just try and
385 * mount to root most subvolume.
387 btrfs_free_path(path
);
388 dir_id
= BTRFS_FIRST_FREE_OBJECTID
;
389 new_root
= root
->fs_info
->fs_root
;
393 btrfs_dir_item_key_to_cpu(path
->nodes
[0], di
, &location
);
394 btrfs_free_path(path
);
397 new_root
= btrfs_read_fs_root_no_name(root
->fs_info
, &location
);
398 if (IS_ERR(new_root
))
399 return ERR_CAST(new_root
);
401 if (btrfs_root_refs(&new_root
->root_item
) == 0)
402 return ERR_PTR(-ENOENT
);
404 dir_id
= btrfs_root_dirid(&new_root
->root_item
);
406 location
.objectid
= dir_id
;
407 location
.type
= BTRFS_INODE_ITEM_KEY
;
410 inode
= btrfs_iget(sb
, &location
, new_root
, &new);
412 return ERR_CAST(inode
);
415 * If we're just mounting the root most subvol put the inode and return
416 * a reference to the dentry. We will have already gotten a reference
417 * to the inode in btrfs_fill_super so we're good to go.
419 if (!new && sb
->s_root
->d_inode
== inode
) {
421 return dget(sb
->s_root
);
425 const struct qstr name
= { .name
= "/", .len
= 1 };
428 * New inode, we need to make the dentry a sibling of s_root so
429 * everything gets cleaned up properly on unmount.
431 dentry
= d_alloc(sb
->s_root
, &name
);
434 return ERR_PTR(-ENOMEM
);
436 d_splice_alias(inode
, dentry
);
439 * We found the inode in cache, just find a dentry for it and
440 * put the reference to the inode we just got.
442 dentry
= d_find_alias(inode
);
449 static int btrfs_fill_super(struct super_block
*sb
,
450 struct btrfs_fs_devices
*fs_devices
,
451 void *data
, int silent
)
454 struct dentry
*root_dentry
;
455 struct btrfs_root
*tree_root
;
456 struct btrfs_key key
;
459 sb
->s_maxbytes
= MAX_LFS_FILESIZE
;
460 sb
->s_magic
= BTRFS_SUPER_MAGIC
;
461 sb
->s_op
= &btrfs_super_ops
;
462 sb
->s_export_op
= &btrfs_export_ops
;
463 sb
->s_xattr
= btrfs_xattr_handlers
;
465 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
466 sb
->s_flags
|= MS_POSIXACL
;
469 tree_root
= open_ctree(sb
, fs_devices
, (char *)data
);
471 if (IS_ERR(tree_root
)) {
472 printk("btrfs: open_ctree failed\n");
473 return PTR_ERR(tree_root
);
475 sb
->s_fs_info
= tree_root
;
477 key
.objectid
= BTRFS_FIRST_FREE_OBJECTID
;
478 key
.type
= BTRFS_INODE_ITEM_KEY
;
480 inode
= btrfs_iget(sb
, &key
, tree_root
->fs_info
->fs_root
, NULL
);
482 err
= PTR_ERR(inode
);
486 root_dentry
= d_alloc_root(inode
);
493 sb
->s_root
= root_dentry
;
495 save_mount_options(sb
, data
);
499 close_ctree(tree_root
);
503 int btrfs_sync_fs(struct super_block
*sb
, int wait
)
505 struct btrfs_trans_handle
*trans
;
506 struct btrfs_root
*root
= btrfs_sb(sb
);
510 filemap_flush(root
->fs_info
->btree_inode
->i_mapping
);
514 btrfs_start_delalloc_inodes(root
, 0);
515 btrfs_wait_ordered_extents(root
, 0, 0);
517 trans
= btrfs_start_transaction(root
, 0);
518 ret
= btrfs_commit_transaction(trans
, root
);
522 static int btrfs_show_options(struct seq_file
*seq
, struct vfsmount
*vfs
)
524 struct btrfs_root
*root
= btrfs_sb(vfs
->mnt_sb
);
525 struct btrfs_fs_info
*info
= root
->fs_info
;
527 if (btrfs_test_opt(root
, DEGRADED
))
528 seq_puts(seq
, ",degraded");
529 if (btrfs_test_opt(root
, NODATASUM
))
530 seq_puts(seq
, ",nodatasum");
531 if (btrfs_test_opt(root
, NODATACOW
))
532 seq_puts(seq
, ",nodatacow");
533 if (btrfs_test_opt(root
, NOBARRIER
))
534 seq_puts(seq
, ",nobarrier");
535 if (info
->max_inline
!= 8192 * 1024)
536 seq_printf(seq
, ",max_inline=%llu",
537 (unsigned long long)info
->max_inline
);
538 if (info
->alloc_start
!= 0)
539 seq_printf(seq
, ",alloc_start=%llu",
540 (unsigned long long)info
->alloc_start
);
541 if (info
->thread_pool_size
!= min_t(unsigned long,
542 num_online_cpus() + 2, 8))
543 seq_printf(seq
, ",thread_pool=%d", info
->thread_pool_size
);
544 if (btrfs_test_opt(root
, COMPRESS
))
545 seq_puts(seq
, ",compress");
546 if (btrfs_test_opt(root
, NOSSD
))
547 seq_puts(seq
, ",nossd");
548 if (btrfs_test_opt(root
, SSD_SPREAD
))
549 seq_puts(seq
, ",ssd_spread");
550 else if (btrfs_test_opt(root
, SSD
))
551 seq_puts(seq
, ",ssd");
552 if (btrfs_test_opt(root
, NOTREELOG
))
553 seq_puts(seq
, ",notreelog");
554 if (btrfs_test_opt(root
, FLUSHONCOMMIT
))
555 seq_puts(seq
, ",flushoncommit");
556 if (btrfs_test_opt(root
, DISCARD
))
557 seq_puts(seq
, ",discard");
558 if (!(root
->fs_info
->sb
->s_flags
& MS_POSIXACL
))
559 seq_puts(seq
, ",noacl");
563 static int btrfs_test_super(struct super_block
*s
, void *data
)
565 struct btrfs_fs_devices
*test_fs_devices
= data
;
566 struct btrfs_root
*root
= btrfs_sb(s
);
568 return root
->fs_info
->fs_devices
== test_fs_devices
;
572 * Find a superblock for the given device / mount point.
574 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
575 * for multiple device setup. Make sure to keep it in sync.
577 static struct dentry
*btrfs_mount(struct file_system_type
*fs_type
, int flags
,
578 const char *dev_name
, void *data
)
580 struct block_device
*bdev
= NULL
;
581 struct super_block
*s
;
583 struct btrfs_fs_devices
*fs_devices
= NULL
;
584 fmode_t mode
= FMODE_READ
;
585 char *subvol_name
= NULL
;
586 u64 subvol_objectid
= 0;
589 if (!(flags
& MS_RDONLY
))
592 error
= btrfs_parse_early_options(data
, mode
, fs_type
,
593 &subvol_name
, &subvol_objectid
,
596 return ERR_PTR(error
);
598 error
= btrfs_scan_one_device(dev_name
, mode
, fs_type
, &fs_devices
);
600 goto error_free_subvol_name
;
602 error
= btrfs_open_devices(fs_devices
, mode
, fs_type
);
604 goto error_free_subvol_name
;
606 if (!(flags
& MS_RDONLY
) && fs_devices
->rw_devices
== 0) {
608 goto error_close_devices
;
611 bdev
= fs_devices
->latest_bdev
;
612 s
= sget(fs_type
, btrfs_test_super
, set_anon_super
, fs_devices
);
617 if ((flags
^ s
->s_flags
) & MS_RDONLY
) {
618 deactivate_locked_super(s
);
620 goto error_close_devices
;
623 btrfs_close_devices(fs_devices
);
625 char b
[BDEVNAME_SIZE
];
628 strlcpy(s
->s_id
, bdevname(bdev
, b
), sizeof(s
->s_id
));
629 error
= btrfs_fill_super(s
, fs_devices
, data
,
630 flags
& MS_SILENT
? 1 : 0);
632 deactivate_locked_super(s
);
633 goto error_free_subvol_name
;
636 btrfs_sb(s
)->fs_info
->bdev_holder
= fs_type
;
637 s
->s_flags
|= MS_ACTIVE
;
640 root
= get_default_root(s
, subvol_objectid
);
642 error
= PTR_ERR(root
);
643 deactivate_locked_super(s
);
644 goto error_free_subvol_name
;
646 /* if they gave us a subvolume name bind mount into that */
647 if (strcmp(subvol_name
, ".")) {
648 struct dentry
*new_root
;
649 mutex_lock(&root
->d_inode
->i_mutex
);
650 new_root
= lookup_one_len(subvol_name
, root
,
651 strlen(subvol_name
));
652 mutex_unlock(&root
->d_inode
->i_mutex
);
654 if (IS_ERR(new_root
)) {
655 deactivate_locked_super(s
);
656 error
= PTR_ERR(new_root
);
658 goto error_free_subvol_name
;
660 if (!new_root
->d_inode
) {
663 deactivate_locked_super(s
);
665 goto error_free_subvol_name
;
677 btrfs_close_devices(fs_devices
);
678 error_free_subvol_name
:
680 return ERR_PTR(error
);
683 static int btrfs_remount(struct super_block
*sb
, int *flags
, char *data
)
685 struct btrfs_root
*root
= btrfs_sb(sb
);
688 ret
= btrfs_parse_options(root
, data
);
692 if ((*flags
& MS_RDONLY
) == (sb
->s_flags
& MS_RDONLY
))
695 if (*flags
& MS_RDONLY
) {
696 sb
->s_flags
|= MS_RDONLY
;
698 ret
= btrfs_commit_super(root
);
701 if (root
->fs_info
->fs_devices
->rw_devices
== 0)
704 if (btrfs_super_log_root(&root
->fs_info
->super_copy
) != 0)
707 ret
= btrfs_cleanup_fs_roots(root
->fs_info
);
710 /* recover relocation */
711 ret
= btrfs_recover_relocation(root
);
714 sb
->s_flags
&= ~MS_RDONLY
;
720 static int btrfs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
722 struct btrfs_root
*root
= btrfs_sb(dentry
->d_sb
);
723 struct btrfs_super_block
*disk_super
= &root
->fs_info
->super_copy
;
724 struct list_head
*head
= &root
->fs_info
->space_info
;
725 struct btrfs_space_info
*found
;
727 u64 total_used_data
= 0;
728 int bits
= dentry
->d_sb
->s_blocksize_bits
;
729 __be32
*fsid
= (__be32
*)root
->fs_info
->fsid
;
732 list_for_each_entry_rcu(found
, head
, list
) {
733 if (found
->flags
& (BTRFS_BLOCK_GROUP_METADATA
|
734 BTRFS_BLOCK_GROUP_SYSTEM
))
735 total_used_data
+= found
->disk_total
;
737 total_used_data
+= found
->disk_used
;
738 total_used
+= found
->disk_used
;
742 buf
->f_namelen
= BTRFS_NAME_LEN
;
743 buf
->f_blocks
= btrfs_super_total_bytes(disk_super
) >> bits
;
744 buf
->f_bfree
= buf
->f_blocks
- (total_used
>> bits
);
745 buf
->f_bavail
= buf
->f_blocks
- (total_used_data
>> bits
);
746 buf
->f_bsize
= dentry
->d_sb
->s_blocksize
;
747 buf
->f_type
= BTRFS_SUPER_MAGIC
;
749 /* We treat it as constant endianness (it doesn't matter _which_)
750 because we want the fsid to come out the same whether mounted
751 on a big-endian or little-endian host */
752 buf
->f_fsid
.val
[0] = be32_to_cpu(fsid
[0]) ^ be32_to_cpu(fsid
[2]);
753 buf
->f_fsid
.val
[1] = be32_to_cpu(fsid
[1]) ^ be32_to_cpu(fsid
[3]);
754 /* Mask in the root object ID too, to disambiguate subvols */
755 buf
->f_fsid
.val
[0] ^= BTRFS_I(dentry
->d_inode
)->root
->objectid
>> 32;
756 buf
->f_fsid
.val
[1] ^= BTRFS_I(dentry
->d_inode
)->root
->objectid
;
761 static struct file_system_type btrfs_fs_type
= {
762 .owner
= THIS_MODULE
,
764 .mount
= btrfs_mount
,
765 .kill_sb
= kill_anon_super
,
766 .fs_flags
= FS_REQUIRES_DEV
,
770 * used by btrfsctl to scan devices when no FS is mounted
772 static long btrfs_control_ioctl(struct file
*file
, unsigned int cmd
,
775 struct btrfs_ioctl_vol_args
*vol
;
776 struct btrfs_fs_devices
*fs_devices
;
779 if (!capable(CAP_SYS_ADMIN
))
782 vol
= memdup_user((void __user
*)arg
, sizeof(*vol
));
787 case BTRFS_IOC_SCAN_DEV
:
788 ret
= btrfs_scan_one_device(vol
->name
, FMODE_READ
,
789 &btrfs_fs_type
, &fs_devices
);
797 static int btrfs_freeze(struct super_block
*sb
)
799 struct btrfs_root
*root
= btrfs_sb(sb
);
800 mutex_lock(&root
->fs_info
->transaction_kthread_mutex
);
801 mutex_lock(&root
->fs_info
->cleaner_mutex
);
805 static int btrfs_unfreeze(struct super_block
*sb
)
807 struct btrfs_root
*root
= btrfs_sb(sb
);
808 mutex_unlock(&root
->fs_info
->cleaner_mutex
);
809 mutex_unlock(&root
->fs_info
->transaction_kthread_mutex
);
813 static const struct super_operations btrfs_super_ops
= {
814 .drop_inode
= btrfs_drop_inode
,
815 .evict_inode
= btrfs_evict_inode
,
816 .put_super
= btrfs_put_super
,
817 .sync_fs
= btrfs_sync_fs
,
818 .show_options
= btrfs_show_options
,
819 .write_inode
= btrfs_write_inode
,
820 .dirty_inode
= btrfs_dirty_inode
,
821 .alloc_inode
= btrfs_alloc_inode
,
822 .destroy_inode
= btrfs_destroy_inode
,
823 .statfs
= btrfs_statfs
,
824 .remount_fs
= btrfs_remount
,
825 .freeze_fs
= btrfs_freeze
,
826 .unfreeze_fs
= btrfs_unfreeze
,
829 static const struct file_operations btrfs_ctl_fops
= {
830 .unlocked_ioctl
= btrfs_control_ioctl
,
831 .compat_ioctl
= btrfs_control_ioctl
,
832 .owner
= THIS_MODULE
,
833 .llseek
= noop_llseek
,
836 static struct miscdevice btrfs_misc
= {
837 .minor
= BTRFS_MINOR
,
838 .name
= "btrfs-control",
839 .fops
= &btrfs_ctl_fops
842 MODULE_ALIAS_MISCDEV(BTRFS_MINOR
);
843 MODULE_ALIAS("devname:btrfs-control");
845 static int btrfs_interface_init(void)
847 return misc_register(&btrfs_misc
);
850 static void btrfs_interface_exit(void)
852 if (misc_deregister(&btrfs_misc
) < 0)
853 printk(KERN_INFO
"misc_deregister failed for control device");
856 static int __init
init_btrfs_fs(void)
860 err
= btrfs_init_sysfs();
864 err
= btrfs_init_cachep();
868 err
= extent_io_init();
872 err
= extent_map_init();
876 err
= btrfs_interface_init();
878 goto free_extent_map
;
880 err
= register_filesystem(&btrfs_fs_type
);
882 goto unregister_ioctl
;
884 printk(KERN_INFO
"%s loaded\n", BTRFS_BUILD_VERSION
);
888 btrfs_interface_exit();
894 btrfs_destroy_cachep();
900 static void __exit
exit_btrfs_fs(void)
902 btrfs_destroy_cachep();
905 btrfs_interface_exit();
906 unregister_filesystem(&btrfs_fs_type
);
908 btrfs_cleanup_fs_uuids();
912 module_init(init_btrfs_fs
)
913 module_exit(exit_btrfs_fs
)
915 MODULE_LICENSE("GPL");