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/string.h>
28 #include <linux/smp_lock.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>
39 #include "transaction.h"
40 #include "btrfs_inode.h"
42 #include "print-tree.h"
44 #define BTRFS_SUPER_MAGIC 0x9123683E
46 static struct super_operations btrfs_super_ops
;
48 static void btrfs_put_super (struct super_block
* sb
)
50 struct btrfs_root
*root
= btrfs_sb(sb
);
51 struct btrfs_fs_info
*fs
= root
->fs_info
;
54 ret
= close_ctree(root
);
56 printk("close ctree returns %d\n", ret
);
58 btrfs_sysfs_del_super(fs
);
66 static match_table_t tokens
= {
67 {Opt_subvol
, "subvol=%s"},
71 static int parse_options (char * options
,
72 struct btrfs_root
*root
,
76 substring_t args
[MAX_OPT_ARGS
];
80 while ((p
= strsep (&options
, ",")) != NULL
) {
85 token
= match_token(p
, tokens
, args
);
88 *subvol_name
= match_strdup(&args
[0]);
97 static int btrfs_fill_super(struct super_block
* sb
, void * data
, int silent
)
100 struct dentry
* root_dentry
;
101 struct btrfs_super_block
*disk_super
;
102 struct btrfs_root
*tree_root
;
103 struct btrfs_inode
*bi
;
106 sb
->s_maxbytes
= MAX_LFS_FILESIZE
;
107 sb
->s_magic
= BTRFS_SUPER_MAGIC
;
108 sb
->s_op
= &btrfs_super_ops
;
111 tree_root
= open_ctree(sb
);
113 if (!tree_root
|| IS_ERR(tree_root
)) {
114 printk("btrfs: open_ctree failed\n");
117 sb
->s_fs_info
= tree_root
;
118 disk_super
= &tree_root
->fs_info
->super_copy
;
119 inode
= btrfs_iget_locked(sb
, btrfs_super_root_dir(disk_super
),
122 bi
->location
.objectid
= inode
->i_ino
;
123 bi
->location
.offset
= 0;
124 bi
->root
= tree_root
;
126 btrfs_set_key_type(&bi
->location
, BTRFS_INODE_ITEM_KEY
);
132 if (inode
->i_state
& I_NEW
) {
133 btrfs_read_locked_inode(inode
);
134 unlock_new_inode(inode
);
137 root_dentry
= d_alloc_root(inode
);
144 /* this does the super kobj at the same time */
145 err
= btrfs_sysfs_add_super(tree_root
->fs_info
);
149 sb
->s_root
= root_dentry
;
150 btrfs_transaction_queue_work(tree_root
, HZ
* 30);
154 close_ctree(tree_root
);
158 static int btrfs_sync_fs(struct super_block
*sb
, int wait
)
160 struct btrfs_trans_handle
*trans
;
161 struct btrfs_root
*root
;
167 filemap_flush(root
->fs_info
->btree_inode
->i_mapping
);
170 btrfs_clean_old_snapshots(root
);
171 mutex_lock(&root
->fs_info
->fs_mutex
);
172 btrfs_defrag_dirty_roots(root
->fs_info
);
173 trans
= btrfs_start_transaction(root
, 1);
174 ret
= btrfs_commit_transaction(trans
, root
);
176 mutex_unlock(&root
->fs_info
->fs_mutex
);
180 static void btrfs_write_super(struct super_block
*sb
)
186 * This is almost a copy of get_sb_bdev in fs/super.c.
187 * We need the local copy to allow direct mounting of
188 * subvolumes, but this could be easily integrated back
189 * into the generic version. --hch
192 /* start copy & paste */
193 static int set_bdev_super(struct super_block
*s
, void *data
)
196 s
->s_dev
= s
->s_bdev
->bd_dev
;
200 static int test_bdev_super(struct super_block
*s
, void *data
)
202 return (void *)s
->s_bdev
== data
;
205 int btrfs_get_sb_bdev(struct file_system_type
*fs_type
,
206 int flags
, const char *dev_name
, void *data
,
207 int (*fill_super
)(struct super_block
*, void *, int),
208 struct vfsmount
*mnt
, const char *subvol
)
210 struct block_device
*bdev
= NULL
;
211 struct super_block
*s
;
215 bdev
= open_bdev_excl(dev_name
, flags
, fs_type
);
217 return PTR_ERR(bdev
);
220 * once the super is inserted into the list by sget, s_umount
221 * will protect the lockfs code from trying to start a snapshot
222 * while we are mounting
224 down(&bdev
->bd_mount_sem
);
225 s
= sget(fs_type
, test_bdev_super
, set_bdev_super
, bdev
);
226 up(&bdev
->bd_mount_sem
);
231 if ((flags
^ s
->s_flags
) & MS_RDONLY
) {
232 up_write(&s
->s_umount
);
238 close_bdev_excl(bdev
);
240 char b
[BDEVNAME_SIZE
];
243 strlcpy(s
->s_id
, bdevname(bdev
, b
), sizeof(s
->s_id
));
244 sb_set_blocksize(s
, block_size(bdev
));
245 error
= fill_super(s
, data
, flags
& MS_SILENT
? 1 : 0);
247 up_write(&s
->s_umount
);
252 s
->s_flags
|= MS_ACTIVE
;
256 root
= lookup_one_len(subvol
, s
->s_root
, strlen(subvol
));
258 up_write(&s
->s_umount
);
260 error
= PTR_ERR(root
);
263 if (!root
->d_inode
) {
265 up_write(&s
->s_umount
);
271 root
= dget(s
->s_root
);
275 mnt
->mnt_root
= root
;
281 close_bdev_excl(bdev
);
285 /* end copy & paste */
287 static int btrfs_get_sb(struct file_system_type
*fs_type
,
288 int flags
, const char *dev_name
, void *data
, struct vfsmount
*mnt
)
291 char *subvol_name
= NULL
;
293 parse_options((char *)data
, NULL
, &subvol_name
);
294 ret
= btrfs_get_sb_bdev(fs_type
, flags
, dev_name
, data
,
295 btrfs_fill_super
, mnt
,
296 subvol_name
? subvol_name
: "default");
300 static int btrfs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
302 struct btrfs_root
*root
= btrfs_sb(dentry
->d_sb
);
303 struct btrfs_super_block
*disk_super
= &root
->fs_info
->super_copy
;
304 int bits
= dentry
->d_sb
->s_blocksize_bits
;
306 buf
->f_namelen
= BTRFS_NAME_LEN
;
307 buf
->f_blocks
= btrfs_super_total_bytes(disk_super
) >> bits
;
308 buf
->f_bfree
= buf
->f_blocks
-
309 (btrfs_super_bytes_used(disk_super
) >> bits
);
310 buf
->f_bavail
= buf
->f_bfree
;
311 buf
->f_bsize
= dentry
->d_sb
->s_blocksize
;
312 buf
->f_type
= BTRFS_SUPER_MAGIC
;
316 static struct file_system_type btrfs_fs_type
= {
317 .owner
= THIS_MODULE
,
319 .get_sb
= btrfs_get_sb
,
320 .kill_sb
= kill_block_super
,
321 .fs_flags
= FS_REQUIRES_DEV
,
324 static struct super_operations btrfs_super_ops
= {
325 .delete_inode
= btrfs_delete_inode
,
326 .put_super
= btrfs_put_super
,
327 .read_inode
= btrfs_read_locked_inode
,
328 .write_super
= btrfs_write_super
,
329 .sync_fs
= btrfs_sync_fs
,
330 .write_inode
= btrfs_write_inode
,
331 .dirty_inode
= btrfs_dirty_inode
,
332 .alloc_inode
= btrfs_alloc_inode
,
333 .destroy_inode
= btrfs_destroy_inode
,
334 .statfs
= btrfs_statfs
,
337 static int __init
init_btrfs_fs(void)
341 err
= btrfs_init_sysfs();
345 btrfs_init_transaction_sys();
346 err
= btrfs_init_cachep();
350 return register_filesystem(&btrfs_fs_type
);
353 static void __exit
exit_btrfs_fs(void)
355 btrfs_exit_transaction_sys();
356 btrfs_destroy_cachep();
358 unregister_filesystem(&btrfs_fs_type
);
362 module_init(init_btrfs_fs
)
363 module_exit(exit_btrfs_fs
)
365 MODULE_LICENSE("GPL");