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"
45 #define BTRFS_SUPER_MAGIC 0x9123683E
47 static struct super_operations btrfs_super_ops;
49 static void btrfs_put_super (struct super_block * sb)
51 struct btrfs_root *root = btrfs_sb(sb);
52 struct btrfs_fs_info *fs = root->fs_info;
55 ret = close_ctree(root);
57 printk("close ctree returns %d\n", ret);
59 btrfs_sysfs_del_super(fs);
67 static match_table_t tokens = {
68 {Opt_subvol, "subvol=%s"},
72 static int parse_options (char * options,
73 struct btrfs_root *root,
77 substring_t args[MAX_OPT_ARGS];
81 while ((p = strsep (&options, ",")) != NULL) {
86 token = match_token(p, tokens, args);
89 *subvol_name = match_strdup(&args[0]);
98 static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
100 struct inode * inode;
101 struct dentry * root_dentry;
102 struct btrfs_super_block *disk_super;
103 struct btrfs_root *tree_root;
104 struct btrfs_inode *bi;
107 sb->s_maxbytes = MAX_LFS_FILESIZE;
108 sb->s_magic = BTRFS_SUPER_MAGIC;
109 sb->s_op = &btrfs_super_ops;
110 sb->s_xattr = btrfs_xattr_handlers;
113 tree_root = open_ctree(sb);
115 if (!tree_root || IS_ERR(tree_root)) {
116 printk("btrfs: open_ctree failed\n");
119 sb->s_fs_info = tree_root;
120 disk_super = &tree_root->fs_info->super_copy;
121 inode = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super),
124 bi->location.objectid = inode->i_ino;
125 bi->location.offset = 0;
126 bi->root = tree_root;
128 btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
134 if (inode->i_state & I_NEW) {
135 btrfs_read_locked_inode(inode);
136 unlock_new_inode(inode);
139 root_dentry = d_alloc_root(inode);
146 /* this does the super kobj at the same time */
147 err = btrfs_sysfs_add_super(tree_root->fs_info);
151 sb->s_root = root_dentry;
152 btrfs_transaction_queue_work(tree_root, HZ * 30);
156 close_ctree(tree_root);
160 static int btrfs_sync_fs(struct super_block *sb, int wait)
162 struct btrfs_trans_handle *trans;
163 struct btrfs_root *root;
169 filemap_flush(root->fs_info->btree_inode->i_mapping);
172 btrfs_clean_old_snapshots(root);
173 mutex_lock(&root->fs_info->fs_mutex);
174 btrfs_defrag_dirty_roots(root->fs_info);
175 trans = btrfs_start_transaction(root, 1);
176 ret = btrfs_commit_transaction(trans, root);
178 mutex_unlock(&root->fs_info->fs_mutex);
182 static void btrfs_write_super(struct super_block *sb)
188 * This is almost a copy of get_sb_bdev in fs/super.c.
189 * We need the local copy to allow direct mounting of
190 * subvolumes, but this could be easily integrated back
191 * into the generic version. --hch
194 /* start copy & paste */
195 static int set_bdev_super(struct super_block *s, void *data)
198 s->s_dev = s->s_bdev->bd_dev;
202 static int test_bdev_super(struct super_block *s, void *data)
204 return (void *)s->s_bdev == data;
207 int btrfs_get_sb_bdev(struct file_system_type *fs_type,
208 int flags, const char *dev_name, void *data,
209 int (*fill_super)(struct super_block *, void *, int),
210 struct vfsmount *mnt, const char *subvol)
212 struct block_device *bdev = NULL;
213 struct super_block *s;
217 bdev = open_bdev_excl(dev_name, flags, fs_type);
219 return PTR_ERR(bdev);
222 * once the super is inserted into the list by sget, s_umount
223 * will protect the lockfs code from trying to start a snapshot
224 * while we are mounting
226 down(&bdev->bd_mount_sem);
227 s = sget(fs_type, test_bdev_super, set_bdev_super, bdev);
228 up(&bdev->bd_mount_sem);
233 if ((flags ^ s->s_flags) & MS_RDONLY) {
234 up_write(&s->s_umount);
240 close_bdev_excl(bdev);
242 char b[BDEVNAME_SIZE];
245 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
246 sb_set_blocksize(s, block_size(bdev));
247 error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
249 up_write(&s->s_umount);
254 s->s_flags |= MS_ACTIVE;
258 root = lookup_one_len(subvol, s->s_root, strlen(subvol));
260 up_write(&s->s_umount);
262 error = PTR_ERR(root);
265 if (!root->d_inode) {
267 up_write(&s->s_umount);
273 root = dget(s->s_root);
277 mnt->mnt_root = root;
283 close_bdev_excl(bdev);
287 /* end copy & paste */
289 static int btrfs_get_sb(struct file_system_type *fs_type,
290 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
293 char *subvol_name = NULL;
295 parse_options((char *)data, NULL, &subvol_name);
296 ret = btrfs_get_sb_bdev(fs_type, flags, dev_name, data,
297 btrfs_fill_super, mnt,
298 subvol_name ? subvol_name : "default");
302 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
304 struct btrfs_root *root = btrfs_sb(dentry->d_sb);
305 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
306 int bits = dentry->d_sb->s_blocksize_bits;
308 buf->f_namelen = BTRFS_NAME_LEN;
309 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
310 buf->f_bfree = buf->f_blocks -
311 (btrfs_super_bytes_used(disk_super) >> bits);
312 buf->f_bavail = buf->f_bfree;
313 buf->f_bsize = dentry->d_sb->s_blocksize;
314 buf->f_type = BTRFS_SUPER_MAGIC;
318 static struct file_system_type btrfs_fs_type = {
319 .owner = THIS_MODULE,
321 .get_sb = btrfs_get_sb,
322 .kill_sb = kill_block_super,
323 .fs_flags = FS_REQUIRES_DEV,
326 static struct super_operations btrfs_super_ops = {
327 .delete_inode = btrfs_delete_inode,
328 .put_super = btrfs_put_super,
329 .read_inode = btrfs_read_locked_inode,
330 .write_super = btrfs_write_super,
331 .sync_fs = btrfs_sync_fs,
332 .write_inode = btrfs_write_inode,
333 .dirty_inode = btrfs_dirty_inode,
334 .alloc_inode = btrfs_alloc_inode,
335 .destroy_inode = btrfs_destroy_inode,
336 .statfs = btrfs_statfs,
339 static int __init init_btrfs_fs(void)
343 err = btrfs_init_sysfs();
347 btrfs_init_transaction_sys();
348 err = btrfs_init_cachep();
352 return register_filesystem(&btrfs_fs_type);
355 static void __exit exit_btrfs_fs(void)
357 btrfs_exit_transaction_sys();
358 btrfs_destroy_cachep();
360 unregister_filesystem(&btrfs_fs_type);
364 module_init(init_btrfs_fs)
365 module_exit(exit_btrfs_fs)
367 MODULE_LICENSE("GPL");