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>
37 #include <linux/ctype.h>
38 #include <linux/namei.h>
41 #include "transaction.h"
42 #include "btrfs_inode.h"
44 #include "print-tree.h"
47 #define BTRFS_SUPER_MAGIC 0x9123683E
49 static struct super_operations btrfs_super_ops
;
51 static void btrfs_put_super (struct super_block
* sb
)
53 struct btrfs_root
*root
= btrfs_sb(sb
);
54 struct btrfs_fs_info
*fs
= root
->fs_info
;
57 ret
= close_ctree(root
);
59 printk("close ctree returns %d\n", ret
);
61 btrfs_sysfs_del_super(fs
);
66 Opt_subvol
, Opt_nodatasum
, Opt_nodatacow
, Opt_max_extent
,
67 Opt_alloc_start
, Opt_nobarrier
, Opt_ssd
, Opt_err
,
70 static match_table_t tokens
= {
71 {Opt_subvol
, "subvol=%s"},
72 {Opt_nodatasum
, "nodatasum"},
73 {Opt_nodatacow
, "nodatacow"},
74 {Opt_nobarrier
, "nobarrier"},
75 {Opt_max_extent
, "max_extent=%s"},
76 {Opt_alloc_start
, "alloc_start=%s"},
81 u64
btrfs_parse_size(char *str
)
88 res
= simple_strtoul(str
, &end
, 10);
106 static int parse_options (char * options
,
107 struct btrfs_root
*root
,
111 struct btrfs_fs_info
*info
= NULL
;
112 substring_t args
[MAX_OPT_ARGS
];
118 * strsep changes the string, duplicate it because parse_options
121 options
= kstrdup(options
, GFP_NOFS
);
126 info
= root
->fs_info
;
128 while ((p
= strsep (&options
, ",")) != NULL
) {
133 token
= match_token(p
, tokens
, args
);
137 *subvol_name
= match_strdup(&args
[0]);
142 printk("btrfs: setting nodatacsum\n");
143 btrfs_set_opt(info
->mount_opt
, NODATASUM
);
148 printk("btrfs: setting nodatacow\n");
149 btrfs_set_opt(info
->mount_opt
, NODATACOW
);
150 btrfs_set_opt(info
->mount_opt
, NODATASUM
);
155 printk("btrfs: use ssd allocation scheme\n");
156 btrfs_set_opt(info
->mount_opt
, SSD
);
161 printk("btrfs: turning off barriers\n");
162 btrfs_set_opt(info
->mount_opt
, NOBARRIER
);
167 char *num
= match_strdup(&args
[0]);
170 btrfs_parse_size(num
);
173 info
->max_extent
= max_t(u64
,
176 printk("btrfs: max_extent at %Lu\n",
181 case Opt_alloc_start
:
183 char *num
= match_strdup(&args
[0]);
186 btrfs_parse_size(num
);
188 printk("btrfs: allocations start at "
189 "%Lu\n", info
->alloc_start
);
201 static int btrfs_fill_super(struct super_block
* sb
, void * data
, int silent
)
203 struct inode
* inode
;
204 struct dentry
* root_dentry
;
205 struct btrfs_super_block
*disk_super
;
206 struct btrfs_root
*tree_root
;
207 struct btrfs_inode
*bi
;
210 sb
->s_maxbytes
= MAX_LFS_FILESIZE
;
211 sb
->s_magic
= BTRFS_SUPER_MAGIC
;
212 sb
->s_op
= &btrfs_super_ops
;
213 sb
->s_xattr
= btrfs_xattr_handlers
;
216 tree_root
= open_ctree(sb
);
218 if (!tree_root
|| IS_ERR(tree_root
)) {
219 printk("btrfs: open_ctree failed\n");
222 sb
->s_fs_info
= tree_root
;
223 disk_super
= &tree_root
->fs_info
->super_copy
;
224 inode
= btrfs_iget_locked(sb
, btrfs_super_root_dir(disk_super
),
227 bi
->location
.objectid
= inode
->i_ino
;
228 bi
->location
.offset
= 0;
229 bi
->root
= tree_root
;
231 btrfs_set_key_type(&bi
->location
, BTRFS_INODE_ITEM_KEY
);
237 if (inode
->i_state
& I_NEW
) {
238 btrfs_read_locked_inode(inode
);
239 unlock_new_inode(inode
);
242 root_dentry
= d_alloc_root(inode
);
249 parse_options((char *)data
, tree_root
, NULL
);
251 /* this does the super kobj at the same time */
252 err
= btrfs_sysfs_add_super(tree_root
->fs_info
);
256 sb
->s_root
= root_dentry
;
257 btrfs_transaction_queue_work(tree_root
, HZ
* 30);
261 close_ctree(tree_root
);
265 static int btrfs_sync_fs(struct super_block
*sb
, int wait
)
267 struct btrfs_trans_handle
*trans
;
268 struct btrfs_root
*root
;
274 filemap_flush(root
->fs_info
->btree_inode
->i_mapping
);
277 btrfs_clean_old_snapshots(root
);
278 mutex_lock(&root
->fs_info
->fs_mutex
);
279 btrfs_defrag_dirty_roots(root
->fs_info
);
280 trans
= btrfs_start_transaction(root
, 1);
281 ret
= btrfs_commit_transaction(trans
, root
);
283 mutex_unlock(&root
->fs_info
->fs_mutex
);
287 static void btrfs_write_super(struct super_block
*sb
)
293 * This is almost a copy of get_sb_bdev in fs/super.c.
294 * We need the local copy to allow direct mounting of
295 * subvolumes, but this could be easily integrated back
296 * into the generic version. --hch
299 /* start copy & paste */
300 static int set_bdev_super(struct super_block
*s
, void *data
)
303 s
->s_dev
= s
->s_bdev
->bd_dev
;
307 static int test_bdev_super(struct super_block
*s
, void *data
)
309 return (void *)s
->s_bdev
== data
;
312 int btrfs_get_sb_bdev(struct file_system_type
*fs_type
,
313 int flags
, const char *dev_name
, void *data
,
314 int (*fill_super
)(struct super_block
*, void *, int),
315 struct vfsmount
*mnt
, const char *subvol
)
317 struct block_device
*bdev
= NULL
;
318 struct super_block
*s
;
322 bdev
= open_bdev_excl(dev_name
, flags
, fs_type
);
324 return PTR_ERR(bdev
);
327 * once the super is inserted into the list by sget, s_umount
328 * will protect the lockfs code from trying to start a snapshot
329 * while we are mounting
331 down(&bdev
->bd_mount_sem
);
332 s
= sget(fs_type
, test_bdev_super
, set_bdev_super
, bdev
);
333 up(&bdev
->bd_mount_sem
);
338 if ((flags
^ s
->s_flags
) & MS_RDONLY
) {
339 up_write(&s
->s_umount
);
345 close_bdev_excl(bdev
);
347 char b
[BDEVNAME_SIZE
];
350 strlcpy(s
->s_id
, bdevname(bdev
, b
), sizeof(s
->s_id
));
351 sb_set_blocksize(s
, block_size(bdev
));
352 error
= fill_super(s
, data
, flags
& MS_SILENT
? 1 : 0);
354 up_write(&s
->s_umount
);
359 s
->s_flags
|= MS_ACTIVE
;
363 root
= lookup_one_len(subvol
, s
->s_root
, strlen(subvol
));
365 up_write(&s
->s_umount
);
367 error
= PTR_ERR(root
);
370 if (!root
->d_inode
) {
372 up_write(&s
->s_umount
);
378 root
= dget(s
->s_root
);
382 mnt
->mnt_root
= root
;
388 close_bdev_excl(bdev
);
392 /* end copy & paste */
394 static int btrfs_get_sb(struct file_system_type
*fs_type
,
395 int flags
, const char *dev_name
, void *data
, struct vfsmount
*mnt
)
398 char *subvol_name
= NULL
;
400 parse_options((char *)data
, NULL
, &subvol_name
);
401 ret
= btrfs_get_sb_bdev(fs_type
, flags
, dev_name
, data
,
402 btrfs_fill_super
, mnt
,
403 subvol_name
? subvol_name
: "default");
409 static int btrfs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
411 struct btrfs_root
*root
= btrfs_sb(dentry
->d_sb
);
412 struct btrfs_super_block
*disk_super
= &root
->fs_info
->super_copy
;
413 int bits
= dentry
->d_sb
->s_blocksize_bits
;
415 buf
->f_namelen
= BTRFS_NAME_LEN
;
416 buf
->f_blocks
= btrfs_super_total_bytes(disk_super
) >> bits
;
417 buf
->f_bfree
= buf
->f_blocks
-
418 (btrfs_super_bytes_used(disk_super
) >> bits
);
419 buf
->f_bavail
= buf
->f_bfree
;
420 buf
->f_bsize
= dentry
->d_sb
->s_blocksize
;
421 buf
->f_type
= BTRFS_SUPER_MAGIC
;
425 static struct file_system_type btrfs_fs_type
= {
426 .owner
= THIS_MODULE
,
428 .get_sb
= btrfs_get_sb
,
429 .kill_sb
= kill_block_super
,
430 .fs_flags
= FS_REQUIRES_DEV
,
432 static void btrfs_write_super_lockfs(struct super_block
*sb
)
434 struct btrfs_root
*root
= btrfs_sb(sb
);
435 btrfs_transaction_flush_work(root
);
438 static void btrfs_unlockfs(struct super_block
*sb
)
440 struct btrfs_root
*root
= btrfs_sb(sb
);
441 btrfs_transaction_queue_work(root
, HZ
* 30);
444 static struct super_operations btrfs_super_ops
= {
445 .delete_inode
= btrfs_delete_inode
,
446 .put_inode
= btrfs_put_inode
,
447 .put_super
= btrfs_put_super
,
448 .read_inode
= btrfs_read_locked_inode
,
449 .write_super
= btrfs_write_super
,
450 .sync_fs
= btrfs_sync_fs
,
451 .write_inode
= btrfs_write_inode
,
452 .dirty_inode
= btrfs_dirty_inode
,
453 .alloc_inode
= btrfs_alloc_inode
,
454 .destroy_inode
= btrfs_destroy_inode
,
455 .statfs
= btrfs_statfs
,
456 .write_super_lockfs
= btrfs_write_super_lockfs
,
457 .unlockfs
= btrfs_unlockfs
,
459 static int __init
init_btrfs_fs(void)
463 err
= btrfs_init_sysfs();
467 btrfs_init_transaction_sys();
468 err
= btrfs_init_cachep();
470 goto free_transaction_sys
;
471 err
= extent_map_init();
475 err
= register_filesystem(&btrfs_fs_type
);
477 goto free_extent_map
;
483 btrfs_destroy_cachep();
484 free_transaction_sys
:
485 btrfs_exit_transaction_sys();
490 static void __exit
exit_btrfs_fs(void)
492 btrfs_exit_transaction_sys();
493 btrfs_destroy_cachep();
495 unregister_filesystem(&btrfs_fs_type
);
499 module_init(init_btrfs_fs
)
500 module_exit(exit_btrfs_fs
)
502 MODULE_LICENSE("GPL");