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>
40 #include <linux/magic.h>
44 #include "transaction.h"
45 #include "btrfs_inode.h"
47 #include "print-tree.h"
52 #include "compression.h"
55 static 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
);
67 Opt_degraded
, Opt_subvol
, Opt_device
, Opt_nodatasum
, Opt_nodatacow
,
68 Opt_max_extent
, Opt_max_inline
, Opt_alloc_start
, Opt_nobarrier
,
69 Opt_ssd
, Opt_thread_pool
, Opt_noacl
, Opt_compress
, Opt_err
,
72 static match_table_t tokens
= {
73 {Opt_degraded
, "degraded"},
74 {Opt_subvol
, "subvol=%s"},
75 {Opt_device
, "device=%s"},
76 {Opt_nodatasum
, "nodatasum"},
77 {Opt_nodatacow
, "nodatacow"},
78 {Opt_nobarrier
, "nobarrier"},
79 {Opt_max_extent
, "max_extent=%s"},
80 {Opt_max_inline
, "max_inline=%s"},
81 {Opt_alloc_start
, "alloc_start=%s"},
82 {Opt_thread_pool
, "thread_pool=%d"},
83 {Opt_compress
, "compress"},
89 u64
btrfs_parse_size(char *str
)
96 res
= simple_strtoul(str
, &end
, 10);
100 last
= tolower(last
);
115 * Regular mount options parser. Everything that is needed only when
116 * reading in a new superblock is parsed here.
118 int btrfs_parse_options(struct btrfs_root
*root
, char *options
)
120 struct btrfs_fs_info
*info
= root
->fs_info
;
121 substring_t args
[MAX_OPT_ARGS
];
129 * strsep changes the string, duplicate it because parse_options
132 options
= kstrdup(options
, GFP_NOFS
);
137 while ((p
= strsep(&options
, ",")) != NULL
) {
142 token
= match_token(p
, tokens
, args
);
145 printk(KERN_INFO
"btrfs: allowing degraded mounts\n");
146 btrfs_set_opt(info
->mount_opt
, DEGRADED
);
151 * These are parsed by btrfs_parse_early_options
152 * and can be happily ignored here.
156 printk(KERN_INFO
"btrfs: setting nodatacsum\n");
157 btrfs_set_opt(info
->mount_opt
, NODATASUM
);
160 printk(KERN_INFO
"btrfs: setting nodatacow\n");
161 btrfs_set_opt(info
->mount_opt
, NODATACOW
);
162 btrfs_set_opt(info
->mount_opt
, NODATASUM
);
165 printk(KERN_INFO
"btrfs: use compression\n");
166 btrfs_set_opt(info
->mount_opt
, COMPRESS
);
169 printk(KERN_INFO
"btrfs: use ssd allocation scheme\n");
170 btrfs_set_opt(info
->mount_opt
, SSD
);
173 printk(KERN_INFO
"btrfs: turning off barriers\n");
174 btrfs_set_opt(info
->mount_opt
, NOBARRIER
);
176 case Opt_thread_pool
:
178 match_int(&args
[0], &intarg
);
180 info
->thread_pool_size
= intarg
;
181 printk(KERN_INFO
"btrfs: thread pool %d\n",
182 info
->thread_pool_size
);
186 num
= match_strdup(&args
[0]);
188 info
->max_extent
= btrfs_parse_size(num
);
191 info
->max_extent
= max_t(u64
,
192 info
->max_extent
, root
->sectorsize
);
193 printk(KERN_INFO
"btrfs: max_extent at %llu\n",
198 num
= match_strdup(&args
[0]);
200 info
->max_inline
= btrfs_parse_size(num
);
203 if (info
->max_inline
) {
204 info
->max_inline
= max_t(u64
,
208 printk(KERN_INFO
"btrfs: max_inline at %llu\n",
212 case Opt_alloc_start
:
213 num
= match_strdup(&args
[0]);
215 info
->alloc_start
= btrfs_parse_size(num
);
218 "btrfs: allocations start at %llu\n",
223 root
->fs_info
->sb
->s_flags
&= ~MS_POSIXACL
;
234 * Parse mount options that are required early in the mount process.
236 * All other options will be parsed on much later in the mount process and
237 * only when we need to allocate a new super block.
239 static int btrfs_parse_early_options(const char *options
, fmode_t flags
,
240 void *holder
, char **subvol_name
,
241 struct btrfs_fs_devices
**fs_devices
)
243 substring_t args
[MAX_OPT_ARGS
];
251 * strsep changes the string, duplicate it because parse_options
254 opts
= kstrdup(options
, GFP_KERNEL
);
258 while ((p
= strsep(&opts
, ",")) != NULL
) {
263 token
= match_token(p
, tokens
, args
);
266 *subvol_name
= match_strdup(&args
[0]);
269 error
= btrfs_scan_one_device(match_strdup(&args
[0]),
270 flags
, holder
, fs_devices
);
283 * If no subvolume name is specified we use the default one. Allocate
284 * a copy of the string "." here so that code later in the
285 * mount path doesn't care if it's the default volume or another one.
288 *subvol_name
= kstrdup(".", GFP_KERNEL
);
295 static int btrfs_fill_super(struct super_block
*sb
,
296 struct btrfs_fs_devices
*fs_devices
,
297 void *data
, int silent
)
300 struct dentry
*root_dentry
;
301 struct btrfs_super_block
*disk_super
;
302 struct btrfs_root
*tree_root
;
303 struct btrfs_inode
*bi
;
306 sb
->s_maxbytes
= MAX_LFS_FILESIZE
;
307 sb
->s_magic
= BTRFS_SUPER_MAGIC
;
308 sb
->s_op
= &btrfs_super_ops
;
309 sb
->s_export_op
= &btrfs_export_ops
;
310 sb
->s_xattr
= btrfs_xattr_handlers
;
312 sb
->s_flags
|= MS_POSIXACL
;
314 tree_root
= open_ctree(sb
, fs_devices
, (char *)data
);
316 if (IS_ERR(tree_root
)) {
317 printk("btrfs: open_ctree failed\n");
318 return PTR_ERR(tree_root
);
320 sb
->s_fs_info
= tree_root
;
321 disk_super
= &tree_root
->fs_info
->super_copy
;
322 inode
= btrfs_iget_locked(sb
, BTRFS_FIRST_FREE_OBJECTID
,
323 tree_root
->fs_info
->fs_root
);
325 bi
->location
.objectid
= inode
->i_ino
;
326 bi
->location
.offset
= 0;
327 bi
->root
= tree_root
->fs_info
->fs_root
;
329 btrfs_set_key_type(&bi
->location
, BTRFS_INODE_ITEM_KEY
);
335 if (inode
->i_state
& I_NEW
) {
336 btrfs_read_locked_inode(inode
);
337 unlock_new_inode(inode
);
340 root_dentry
= d_alloc_root(inode
);
347 /* this does the super kobj at the same time */
348 err
= btrfs_sysfs_add_super(tree_root
->fs_info
);
353 sb
->s_root
= root_dentry
;
355 save_mount_options(sb
, data
);
359 close_ctree(tree_root
);
363 int btrfs_sync_fs(struct super_block
*sb
, int wait
)
365 struct btrfs_trans_handle
*trans
;
366 struct btrfs_root
*root
;
370 if (sb
->s_flags
& MS_RDONLY
)
375 filemap_flush(root
->fs_info
->btree_inode
->i_mapping
);
379 btrfs_start_delalloc_inodes(root
);
380 btrfs_wait_ordered_extents(root
, 0);
382 btrfs_clean_old_snapshots(root
);
383 trans
= btrfs_start_transaction(root
, 1);
384 ret
= btrfs_commit_transaction(trans
, root
);
389 static void btrfs_write_super(struct super_block
*sb
)
394 static int btrfs_test_super(struct super_block
*s
, void *data
)
396 struct btrfs_fs_devices
*test_fs_devices
= data
;
397 struct btrfs_root
*root
= btrfs_sb(s
);
399 return root
->fs_info
->fs_devices
== test_fs_devices
;
403 * Find a superblock for the given device / mount point.
405 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
406 * for multiple device setup. Make sure to keep it in sync.
408 static int btrfs_get_sb(struct file_system_type
*fs_type
, int flags
,
409 const char *dev_name
, void *data
, struct vfsmount
*mnt
)
411 char *subvol_name
= NULL
;
412 struct block_device
*bdev
= NULL
;
413 struct super_block
*s
;
415 struct btrfs_fs_devices
*fs_devices
= NULL
;
416 fmode_t mode
= FMODE_READ
;
419 if (!(flags
& MS_RDONLY
))
422 error
= btrfs_parse_early_options(data
, mode
, fs_type
,
423 &subvol_name
, &fs_devices
);
427 error
= btrfs_scan_one_device(dev_name
, mode
, fs_type
, &fs_devices
);
429 goto error_free_subvol_name
;
431 error
= btrfs_open_devices(fs_devices
, mode
, fs_type
);
433 goto error_free_subvol_name
;
435 if (!(flags
& MS_RDONLY
) && fs_devices
->rw_devices
== 0) {
437 goto error_close_devices
;
440 bdev
= fs_devices
->latest_bdev
;
441 s
= sget(fs_type
, btrfs_test_super
, set_anon_super
, fs_devices
);
446 if ((flags
^ s
->s_flags
) & MS_RDONLY
) {
447 up_write(&s
->s_umount
);
450 goto error_close_devices
;
453 btrfs_close_devices(fs_devices
);
455 char b
[BDEVNAME_SIZE
];
458 strlcpy(s
->s_id
, bdevname(bdev
, b
), sizeof(s
->s_id
));
459 error
= btrfs_fill_super(s
, fs_devices
, data
,
460 flags
& MS_SILENT
? 1 : 0);
462 up_write(&s
->s_umount
);
464 goto error_free_subvol_name
;
467 btrfs_sb(s
)->fs_info
->bdev_holder
= fs_type
;
468 s
->s_flags
|= MS_ACTIVE
;
471 if (!strcmp(subvol_name
, "."))
472 root
= dget(s
->s_root
);
474 mutex_lock(&s
->s_root
->d_inode
->i_mutex
);
475 root
= lookup_one_len(subvol_name
, s
->s_root
,
476 strlen(subvol_name
));
477 mutex_unlock(&s
->s_root
->d_inode
->i_mutex
);
480 up_write(&s
->s_umount
);
482 error
= PTR_ERR(root
);
483 goto error_free_subvol_name
;
485 if (!root
->d_inode
) {
487 up_write(&s
->s_umount
);
490 goto error_free_subvol_name
;
495 mnt
->mnt_root
= root
;
503 btrfs_close_devices(fs_devices
);
504 error_free_subvol_name
:
509 static int btrfs_remount(struct super_block
*sb
, int *flags
, char *data
)
511 struct btrfs_root
*root
= btrfs_sb(sb
);
514 if ((*flags
& MS_RDONLY
) == (sb
->s_flags
& MS_RDONLY
))
517 if (*flags
& MS_RDONLY
) {
518 sb
->s_flags
|= MS_RDONLY
;
520 ret
= btrfs_commit_super(root
);
523 if (root
->fs_info
->fs_devices
->rw_devices
== 0)
526 if (btrfs_super_log_root(&root
->fs_info
->super_copy
) != 0)
529 ret
= btrfs_cleanup_reloc_trees(root
);
532 ret
= btrfs_cleanup_fs_roots(root
->fs_info
);
535 sb
->s_flags
&= ~MS_RDONLY
;
541 static int btrfs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
543 struct btrfs_root
*root
= btrfs_sb(dentry
->d_sb
);
544 struct btrfs_super_block
*disk_super
= &root
->fs_info
->super_copy
;
545 int bits
= dentry
->d_sb
->s_blocksize_bits
;
546 __be32
*fsid
= (__be32
*)root
->fs_info
->fsid
;
548 buf
->f_namelen
= BTRFS_NAME_LEN
;
549 buf
->f_blocks
= btrfs_super_total_bytes(disk_super
) >> bits
;
550 buf
->f_bfree
= buf
->f_blocks
-
551 (btrfs_super_bytes_used(disk_super
) >> bits
);
552 buf
->f_bavail
= buf
->f_bfree
;
553 buf
->f_bsize
= dentry
->d_sb
->s_blocksize
;
554 buf
->f_type
= BTRFS_SUPER_MAGIC
;
556 /* We treat it as constant endianness (it doesn't matter _which_)
557 because we want the fsid to come out the same whether mounted
558 on a big-endian or little-endian host */
559 buf
->f_fsid
.val
[0] = be32_to_cpu(fsid
[0]) ^ be32_to_cpu(fsid
[2]);
560 buf
->f_fsid
.val
[1] = be32_to_cpu(fsid
[1]) ^ be32_to_cpu(fsid
[3]);
561 /* Mask in the root object ID too, to disambiguate subvols */
562 buf
->f_fsid
.val
[0] ^= BTRFS_I(dentry
->d_inode
)->root
->objectid
>> 32;
563 buf
->f_fsid
.val
[1] ^= BTRFS_I(dentry
->d_inode
)->root
->objectid
;
568 static struct file_system_type btrfs_fs_type
= {
569 .owner
= THIS_MODULE
,
571 .get_sb
= btrfs_get_sb
,
572 .kill_sb
= kill_anon_super
,
573 .fs_flags
= FS_REQUIRES_DEV
,
577 * used by btrfsctl to scan devices when no FS is mounted
579 static long btrfs_control_ioctl(struct file
*file
, unsigned int cmd
,
582 struct btrfs_ioctl_vol_args
*vol
;
583 struct btrfs_fs_devices
*fs_devices
;
586 if (!capable(CAP_SYS_ADMIN
))
589 vol
= kmalloc(sizeof(*vol
), GFP_KERNEL
);
593 if (copy_from_user(vol
, (void __user
*)arg
, sizeof(*vol
))) {
599 case BTRFS_IOC_SCAN_DEV
:
600 ret
= btrfs_scan_one_device(vol
->name
, FMODE_READ
,
601 &btrfs_fs_type
, &fs_devices
);
609 static int btrfs_freeze(struct super_block
*sb
)
611 struct btrfs_root
*root
= btrfs_sb(sb
);
612 mutex_lock(&root
->fs_info
->transaction_kthread_mutex
);
613 mutex_lock(&root
->fs_info
->cleaner_mutex
);
617 static int btrfs_unfreeze(struct super_block
*sb
)
619 struct btrfs_root
*root
= btrfs_sb(sb
);
620 mutex_unlock(&root
->fs_info
->cleaner_mutex
);
621 mutex_unlock(&root
->fs_info
->transaction_kthread_mutex
);
625 static struct super_operations btrfs_super_ops
= {
626 .delete_inode
= btrfs_delete_inode
,
627 .put_super
= btrfs_put_super
,
628 .write_super
= btrfs_write_super
,
629 .sync_fs
= btrfs_sync_fs
,
630 .show_options
= generic_show_options
,
631 .write_inode
= btrfs_write_inode
,
632 .dirty_inode
= btrfs_dirty_inode
,
633 .alloc_inode
= btrfs_alloc_inode
,
634 .destroy_inode
= btrfs_destroy_inode
,
635 .statfs
= btrfs_statfs
,
636 .remount_fs
= btrfs_remount
,
637 .freeze_fs
= btrfs_freeze
,
638 .unfreeze_fs
= btrfs_unfreeze
,
641 static const struct file_operations btrfs_ctl_fops
= {
642 .unlocked_ioctl
= btrfs_control_ioctl
,
643 .compat_ioctl
= btrfs_control_ioctl
,
644 .owner
= THIS_MODULE
,
647 static struct miscdevice btrfs_misc
= {
648 .minor
= MISC_DYNAMIC_MINOR
,
649 .name
= "btrfs-control",
650 .fops
= &btrfs_ctl_fops
653 static int btrfs_interface_init(void)
655 return misc_register(&btrfs_misc
);
658 static void btrfs_interface_exit(void)
660 if (misc_deregister(&btrfs_misc
) < 0)
661 printk(KERN_INFO
"misc_deregister failed for control device");
664 static int __init
init_btrfs_fs(void)
668 err
= btrfs_init_sysfs();
672 err
= btrfs_init_cachep();
676 err
= extent_io_init();
680 err
= extent_map_init();
684 err
= btrfs_interface_init();
686 goto free_extent_map
;
688 err
= register_filesystem(&btrfs_fs_type
);
690 goto unregister_ioctl
;
692 printk(KERN_INFO
"%s loaded\n", BTRFS_BUILD_VERSION
);
696 btrfs_interface_exit();
702 btrfs_destroy_cachep();
708 static void __exit
exit_btrfs_fs(void)
710 btrfs_destroy_cachep();
713 btrfs_interface_exit();
714 unregister_filesystem(&btrfs_fs_type
);
716 btrfs_cleanup_fs_uuids();
720 module_init(init_btrfs_fs
)
721 module_exit(exit_btrfs_fs
)
723 MODULE_LICENSE("GPL");