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>
39 #include <linux/miscdevice.h>
42 #include "transaction.h"
43 #include "btrfs_inode.h"
45 #include "print-tree.h"
50 #include "compression.h"
52 #define BTRFS_SUPER_MAGIC 0x9123683E
54 static struct super_operations btrfs_super_ops
;
56 static void btrfs_put_super (struct super_block
* sb
)
58 struct btrfs_root
*root
= btrfs_sb(sb
);
59 struct btrfs_fs_info
*fs
= root
->fs_info
;
62 ret
= close_ctree(root
);
64 printk("close ctree returns %d\n", ret
);
66 btrfs_sysfs_del_super(fs
);
71 Opt_degraded
, Opt_subvol
, Opt_device
, Opt_nodatasum
, Opt_nodatacow
,
72 Opt_max_extent
, Opt_max_inline
, Opt_alloc_start
, Opt_nobarrier
,
73 Opt_ssd
, Opt_thread_pool
, Opt_noacl
, Opt_compress
, Opt_err
,
76 static match_table_t tokens
= {
77 {Opt_degraded
, "degraded"},
78 {Opt_subvol
, "subvol=%s"},
79 {Opt_device
, "device=%s"},
80 {Opt_nodatasum
, "nodatasum"},
81 {Opt_nodatacow
, "nodatacow"},
82 {Opt_nobarrier
, "nobarrier"},
83 {Opt_max_extent
, "max_extent=%s"},
84 {Opt_max_inline
, "max_inline=%s"},
85 {Opt_alloc_start
, "alloc_start=%s"},
86 {Opt_thread_pool
, "thread_pool=%d"},
87 {Opt_compress
, "compress"},
93 u64
btrfs_parse_size(char *str
)
100 res
= simple_strtoul(str
, &end
, 10);
104 last
= tolower(last
);
119 * Regular mount options parser. Everything that is needed only when
120 * reading in a new superblock is parsed here.
122 int btrfs_parse_options(struct btrfs_root
*root
, char *options
)
124 struct btrfs_fs_info
*info
= root
->fs_info
;
125 substring_t args
[MAX_OPT_ARGS
];
133 * strsep changes the string, duplicate it because parse_options
136 options
= kstrdup(options
, GFP_NOFS
);
141 while ((p
= strsep(&options
, ",")) != NULL
) {
146 token
= match_token(p
, tokens
, args
);
149 printk(KERN_INFO
"btrfs: allowing degraded mounts\n");
150 btrfs_set_opt(info
->mount_opt
, DEGRADED
);
155 * These are parsed by btrfs_parse_early_options
156 * and can be happily ignored here.
160 printk(KERN_INFO
"btrfs: setting nodatacsum\n");
161 btrfs_set_opt(info
->mount_opt
, NODATASUM
);
164 printk(KERN_INFO
"btrfs: setting nodatacow\n");
165 btrfs_set_opt(info
->mount_opt
, NODATACOW
);
166 btrfs_set_opt(info
->mount_opt
, NODATASUM
);
169 printk(KERN_INFO
"btrfs: use compression\n");
170 btrfs_set_opt(info
->mount_opt
, COMPRESS
);
173 printk(KERN_INFO
"btrfs: use ssd allocation scheme\n");
174 btrfs_set_opt(info
->mount_opt
, SSD
);
177 printk(KERN_INFO
"btrfs: turning off barriers\n");
178 btrfs_set_opt(info
->mount_opt
, NOBARRIER
);
180 case Opt_thread_pool
:
182 match_int(&args
[0], &intarg
);
184 info
->thread_pool_size
= intarg
;
185 printk(KERN_INFO
"btrfs: thread pool %d\n",
186 info
->thread_pool_size
);
190 num
= match_strdup(&args
[0]);
192 info
->max_extent
= btrfs_parse_size(num
);
195 info
->max_extent
= max_t(u64
,
196 info
->max_extent
, root
->sectorsize
);
197 printk(KERN_INFO
"btrfs: max_extent at %llu\n",
202 num
= match_strdup(&args
[0]);
204 info
->max_inline
= btrfs_parse_size(num
);
207 if (info
->max_inline
) {
208 info
->max_inline
= max_t(u64
,
212 printk(KERN_INFO
"btrfs: max_inline at %llu\n",
216 case Opt_alloc_start
:
217 num
= match_strdup(&args
[0]);
219 info
->alloc_start
= btrfs_parse_size(num
);
222 "btrfs: allocations start at %llu\n",
227 root
->fs_info
->sb
->s_flags
&= ~MS_POSIXACL
;
238 * Parse mount options that are required early in the mount process.
240 * All other options will be parsed on much later in the mount process and
241 * only when we need to allocate a new super block.
243 static int btrfs_parse_early_options(const char *options
, int flags
,
244 void *holder
, char **subvol_name
,
245 struct btrfs_fs_devices
**fs_devices
)
247 substring_t args
[MAX_OPT_ARGS
];
255 * strsep changes the string, duplicate it because parse_options
258 opts
= kstrdup(options
, GFP_KERNEL
);
262 while ((p
= strsep(&opts
, ",")) != NULL
) {
267 token
= match_token(p
, tokens
, args
);
270 *subvol_name
= match_strdup(&args
[0]);
273 error
= btrfs_scan_one_device(match_strdup(&args
[0]),
274 flags
, holder
, fs_devices
);
287 * If no subvolume name is specified we use the default one. Allocate
288 * a copy of the string "." here so that code later in the
289 * mount path doesn't care if it's the default volume or another one.
292 *subvol_name
= kstrdup(".", GFP_KERNEL
);
299 static int btrfs_fill_super(struct super_block
* sb
,
300 struct btrfs_fs_devices
*fs_devices
,
301 void * data
, int silent
)
303 struct inode
* inode
;
304 struct dentry
* root_dentry
;
305 struct btrfs_super_block
*disk_super
;
306 struct btrfs_root
*tree_root
;
307 struct btrfs_inode
*bi
;
310 sb
->s_maxbytes
= MAX_LFS_FILESIZE
;
311 sb
->s_magic
= BTRFS_SUPER_MAGIC
;
312 sb
->s_op
= &btrfs_super_ops
;
313 sb
->s_export_op
= &btrfs_export_ops
;
314 sb
->s_xattr
= btrfs_xattr_handlers
;
316 sb
->s_flags
|= MS_POSIXACL
;
318 tree_root
= open_ctree(sb
, fs_devices
, (char *)data
);
320 if (IS_ERR(tree_root
)) {
321 printk("btrfs: open_ctree failed\n");
322 return PTR_ERR(tree_root
);
324 sb
->s_fs_info
= tree_root
;
325 disk_super
= &tree_root
->fs_info
->super_copy
;
326 inode
= btrfs_iget_locked(sb
, BTRFS_FIRST_FREE_OBJECTID
,
327 tree_root
->fs_info
->fs_root
);
329 bi
->location
.objectid
= inode
->i_ino
;
330 bi
->location
.offset
= 0;
331 bi
->root
= tree_root
->fs_info
->fs_root
;
333 btrfs_set_key_type(&bi
->location
, BTRFS_INODE_ITEM_KEY
);
339 if (inode
->i_state
& I_NEW
) {
340 btrfs_read_locked_inode(inode
);
341 unlock_new_inode(inode
);
344 root_dentry
= d_alloc_root(inode
);
351 /* this does the super kobj at the same time */
352 err
= btrfs_sysfs_add_super(tree_root
->fs_info
);
356 sb
->s_root
= root_dentry
;
358 save_mount_options(sb
, data
);
362 close_ctree(tree_root
);
366 int btrfs_sync_fs(struct super_block
*sb
, int wait
)
368 struct btrfs_trans_handle
*trans
;
369 struct btrfs_root
*root
;
373 if (sb
->s_flags
& MS_RDONLY
)
378 filemap_flush(root
->fs_info
->btree_inode
->i_mapping
);
382 btrfs_start_delalloc_inodes(root
);
383 btrfs_wait_ordered_extents(root
, 0);
385 btrfs_clean_old_snapshots(root
);
386 trans
= btrfs_start_transaction(root
, 1);
387 ret
= btrfs_commit_transaction(trans
, root
);
392 static void btrfs_write_super(struct super_block
*sb
)
397 static int btrfs_test_super(struct super_block
*s
, void *data
)
399 struct btrfs_fs_devices
*test_fs_devices
= data
;
400 struct btrfs_root
*root
= btrfs_sb(s
);
402 return root
->fs_info
->fs_devices
== test_fs_devices
;
406 * Find a superblock for the given device / mount point.
408 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
409 * for multiple device setup. Make sure to keep it in sync.
411 static int btrfs_get_sb(struct file_system_type
*fs_type
, int flags
,
412 const char *dev_name
, void *data
, struct vfsmount
*mnt
)
414 char *subvol_name
= NULL
;
415 struct block_device
*bdev
= NULL
;
416 struct super_block
*s
;
418 struct btrfs_fs_devices
*fs_devices
= NULL
;
421 error
= btrfs_parse_early_options(data
, flags
, fs_type
,
422 &subvol_name
, &fs_devices
);
426 error
= btrfs_scan_one_device(dev_name
, flags
, fs_type
, &fs_devices
);
428 goto error_free_subvol_name
;
430 error
= btrfs_open_devices(fs_devices
, flags
, fs_type
);
432 goto error_free_subvol_name
;
434 if (!(flags
& MS_RDONLY
) && fs_devices
->rw_devices
== 0) {
436 goto error_close_devices
;
439 bdev
= fs_devices
->latest_bdev
;
440 s
= sget(fs_type
, btrfs_test_super
, set_anon_super
, fs_devices
);
445 if ((flags
^ s
->s_flags
) & MS_RDONLY
) {
446 up_write(&s
->s_umount
);
449 goto error_close_devices
;
452 btrfs_close_devices(fs_devices
);
454 char b
[BDEVNAME_SIZE
];
457 strlcpy(s
->s_id
, bdevname(bdev
, b
), sizeof(s
->s_id
));
458 error
= btrfs_fill_super(s
, fs_devices
, data
,
459 flags
& MS_SILENT
? 1 : 0);
461 up_write(&s
->s_umount
);
466 btrfs_sb(s
)->fs_info
->bdev_holder
= fs_type
;
467 s
->s_flags
|= MS_ACTIVE
;
470 if (!strcmp(subvol_name
, "."))
471 root
= dget(s
->s_root
);
473 mutex_lock(&s
->s_root
->d_inode
->i_mutex
);
474 root
= lookup_one_len(subvol_name
, s
->s_root
, strlen(subvol_name
));
475 mutex_unlock(&s
->s_root
->d_inode
->i_mutex
);
477 up_write(&s
->s_umount
);
479 error
= PTR_ERR(root
);
482 if (!root
->d_inode
) {
484 up_write(&s
->s_umount
);
492 mnt
->mnt_root
= root
;
500 btrfs_close_devices(fs_devices
);
501 error_free_subvol_name
:
507 static int btrfs_remount(struct super_block
*sb
, int *flags
, char *data
)
509 struct btrfs_root
*root
= btrfs_sb(sb
);
512 if ((*flags
& MS_RDONLY
) == (sb
->s_flags
& MS_RDONLY
))
515 if (*flags
& MS_RDONLY
) {
516 sb
->s_flags
|= MS_RDONLY
;
518 ret
= btrfs_commit_super(root
);
521 if (root
->fs_info
->fs_devices
->rw_devices
== 0)
524 if (btrfs_super_log_root(&root
->fs_info
->super_copy
) != 0)
527 ret
= btrfs_cleanup_reloc_trees(root
);
530 ret
= btrfs_cleanup_fs_roots(root
->fs_info
);
533 sb
->s_flags
&= ~MS_RDONLY
;
539 static int btrfs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
541 struct btrfs_root
*root
= btrfs_sb(dentry
->d_sb
);
542 struct btrfs_super_block
*disk_super
= &root
->fs_info
->super_copy
;
543 int bits
= dentry
->d_sb
->s_blocksize_bits
;
544 __be32
*fsid
= (__be32
*)root
->fs_info
->fsid
;
546 buf
->f_namelen
= BTRFS_NAME_LEN
;
547 buf
->f_blocks
= btrfs_super_total_bytes(disk_super
) >> bits
;
548 buf
->f_bfree
= buf
->f_blocks
-
549 (btrfs_super_bytes_used(disk_super
) >> bits
);
550 buf
->f_bavail
= buf
->f_bfree
;
551 buf
->f_bsize
= dentry
->d_sb
->s_blocksize
;
552 buf
->f_type
= BTRFS_SUPER_MAGIC
;
553 /* We treat it as constant endianness (it doesn't matter _which_)
554 because we want the fsid to come out the same whether mounted
555 on a big-endian or little-endian host */
556 buf
->f_fsid
.val
[0] = be32_to_cpu(fsid
[0]) ^ be32_to_cpu(fsid
[2]);
557 buf
->f_fsid
.val
[1] = be32_to_cpu(fsid
[1]) ^ be32_to_cpu(fsid
[3]);
558 /* Mask in the root object ID too, to disambiguate subvols */
559 buf
->f_fsid
.val
[0] ^= BTRFS_I(dentry
->d_inode
)->root
->objectid
>> 32;
560 buf
->f_fsid
.val
[1] ^= BTRFS_I(dentry
->d_inode
)->root
->objectid
;
565 static struct file_system_type btrfs_fs_type
= {
566 .owner
= THIS_MODULE
,
568 .get_sb
= btrfs_get_sb
,
569 .kill_sb
= kill_anon_super
,
570 .fs_flags
= FS_REQUIRES_DEV
,
574 * used by btrfsctl to scan devices when no FS is mounted
576 static long btrfs_control_ioctl(struct file
*file
, unsigned int cmd
,
579 struct btrfs_ioctl_vol_args
*vol
;
580 struct btrfs_fs_devices
*fs_devices
;
584 vol
= kmalloc(sizeof(*vol
), GFP_KERNEL
);
585 if (copy_from_user(vol
, (void __user
*)arg
, sizeof(*vol
))) {
589 len
= strnlen(vol
->name
, BTRFS_PATH_NAME_MAX
);
591 case BTRFS_IOC_SCAN_DEV
:
592 ret
= btrfs_scan_one_device(vol
->name
, MS_RDONLY
,
593 &btrfs_fs_type
, &fs_devices
);
601 static void btrfs_write_super_lockfs(struct super_block
*sb
)
603 struct btrfs_root
*root
= btrfs_sb(sb
);
604 mutex_lock(&root
->fs_info
->transaction_kthread_mutex
);
605 mutex_lock(&root
->fs_info
->cleaner_mutex
);
608 static void btrfs_unlockfs(struct super_block
*sb
)
610 struct btrfs_root
*root
= btrfs_sb(sb
);
611 mutex_unlock(&root
->fs_info
->cleaner_mutex
);
612 mutex_unlock(&root
->fs_info
->transaction_kthread_mutex
);
615 static struct super_operations btrfs_super_ops
= {
616 .delete_inode
= btrfs_delete_inode
,
617 .put_super
= btrfs_put_super
,
618 .write_super
= btrfs_write_super
,
619 .sync_fs
= btrfs_sync_fs
,
620 .show_options
= generic_show_options
,
621 .write_inode
= btrfs_write_inode
,
622 .dirty_inode
= btrfs_dirty_inode
,
623 .alloc_inode
= btrfs_alloc_inode
,
624 .destroy_inode
= btrfs_destroy_inode
,
625 .statfs
= btrfs_statfs
,
626 .remount_fs
= btrfs_remount
,
627 .write_super_lockfs
= btrfs_write_super_lockfs
,
628 .unlockfs
= btrfs_unlockfs
,
631 static const struct file_operations btrfs_ctl_fops
= {
632 .unlocked_ioctl
= btrfs_control_ioctl
,
633 .compat_ioctl
= btrfs_control_ioctl
,
634 .owner
= THIS_MODULE
,
637 static struct miscdevice btrfs_misc
= {
638 .minor
= MISC_DYNAMIC_MINOR
,
639 .name
= "btrfs-control",
640 .fops
= &btrfs_ctl_fops
643 static int btrfs_interface_init(void)
645 return misc_register(&btrfs_misc
);
648 void btrfs_interface_exit(void)
650 if (misc_deregister(&btrfs_misc
) < 0)
651 printk("misc_deregister failed for control device");
654 static int __init
init_btrfs_fs(void)
658 err
= btrfs_init_sysfs();
662 err
= btrfs_init_cachep();
666 err
= extent_io_init();
670 err
= extent_map_init();
674 err
= btrfs_interface_init();
676 goto free_extent_map
;
678 err
= register_filesystem(&btrfs_fs_type
);
680 goto unregister_ioctl
;
682 printk(KERN_INFO
"%s loaded\n", BTRFS_BUILD_VERSION
);
686 btrfs_interface_exit();
692 btrfs_destroy_cachep();
698 static void __exit
exit_btrfs_fs(void)
700 btrfs_destroy_cachep();
703 btrfs_interface_exit();
704 unregister_filesystem(&btrfs_fs_type
);
706 btrfs_cleanup_fs_uuids();
710 module_init(init_btrfs_fs
)
711 module_exit(exit_btrfs_fs
)
713 MODULE_LICENSE("GPL");