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");