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>
38 #include "transaction.h"
39 #include "btrfs_inode.h"
41 #include "print-tree.h"
43 #define BTRFS_SUPER_MAGIC 0x9123682E
45 static struct super_operations btrfs_super_ops;
47 static void btrfs_put_super (struct super_block * sb)
49 struct btrfs_root *root = btrfs_sb(sb);
50 struct btrfs_fs_info *fs = root->fs_info;
53 ret = close_ctree(root);
55 printk("close ctree returns %d\n", ret);
57 btrfs_sysfs_del_super(fs);
61 static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
64 struct dentry * root_dentry;
65 struct btrfs_super_block *disk_super;
66 struct btrfs_root *tree_root;
67 struct btrfs_inode *bi;
70 sb->s_maxbytes = MAX_LFS_FILESIZE;
71 sb->s_magic = BTRFS_SUPER_MAGIC;
72 sb->s_op = &btrfs_super_ops;
75 tree_root = open_ctree(sb);
77 if (!tree_root || IS_ERR(tree_root)) {
78 printk("btrfs: open_ctree failed\n");
81 sb->s_fs_info = tree_root;
82 disk_super = tree_root->fs_info->disk_super;
83 inode = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super),
86 bi->location.objectid = inode->i_ino;
87 bi->location.offset = 0;
88 bi->location.flags = 0;
91 btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
97 if (inode->i_state & I_NEW) {
98 btrfs_read_locked_inode(inode);
99 unlock_new_inode(inode);
102 root_dentry = d_alloc_root(inode);
109 /* this does the super kobj at the same time */
110 err = btrfs_sysfs_add_super(tree_root->fs_info);
114 sb->s_root = root_dentry;
115 btrfs_transaction_queue_work(tree_root, HZ * 30);
119 close_ctree(tree_root);
123 static int btrfs_sync_fs(struct super_block *sb, int wait)
125 struct btrfs_trans_handle *trans;
126 struct btrfs_root *root;
132 filemap_flush(root->fs_info->btree_inode->i_mapping);
135 btrfs_clean_old_snapshots(root);
136 mutex_lock(&root->fs_info->fs_mutex);
137 btrfs_defrag_dirty_roots(root->fs_info);
138 trans = btrfs_start_transaction(root, 1);
139 ret = btrfs_commit_transaction(trans, root);
141 mutex_unlock(&root->fs_info->fs_mutex);
145 static void btrfs_write_super(struct super_block *sb)
151 * This is almost a copy of get_sb_bdev in fs/super.c.
152 * We need the local copy to allow direct mounting of
153 * subvolumes, but this could be easily integrated back
154 * into the generic version. --hch
157 /* start copy & paste */
158 static int set_bdev_super(struct super_block *s, void *data)
161 s->s_dev = s->s_bdev->bd_dev;
165 static int test_bdev_super(struct super_block *s, void *data)
167 return (void *)s->s_bdev == data;
170 int btrfs_get_sb_bdev(struct file_system_type *fs_type,
171 int flags, const char *dev_name, void *data,
172 int (*fill_super)(struct super_block *, void *, int),
173 struct vfsmount *mnt, const char *subvol)
175 struct block_device *bdev = NULL;
176 struct super_block *s;
180 bdev = open_bdev_excl(dev_name, flags, fs_type);
182 return PTR_ERR(bdev);
185 * once the super is inserted into the list by sget, s_umount
186 * will protect the lockfs code from trying to start a snapshot
187 * while we are mounting
189 down(&bdev->bd_mount_sem);
190 s = sget(fs_type, test_bdev_super, set_bdev_super, bdev);
191 up(&bdev->bd_mount_sem);
196 if ((flags ^ s->s_flags) & MS_RDONLY) {
197 up_write(&s->s_umount);
203 close_bdev_excl(bdev);
205 char b[BDEVNAME_SIZE];
208 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
209 sb_set_blocksize(s, block_size(bdev));
210 error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
212 up_write(&s->s_umount);
217 s->s_flags |= MS_ACTIVE;
221 root = lookup_one_len(subvol, s->s_root, strlen(subvol));
223 up_write(&s->s_umount);
225 error = PTR_ERR(root);
228 if (!root->d_inode) {
230 up_write(&s->s_umount);
236 root = dget(s->s_root);
240 mnt->mnt_root = root;
246 close_bdev_excl(bdev);
250 /* end copy & paste */
252 static int btrfs_get_sb(struct file_system_type *fs_type,
253 int flags, const char *identifier, void *data, struct vfsmount *mnt)
256 char *_identifier = kstrdup(identifier, GFP_KERNEL);
258 const char *dev_name;
260 subvol_name = _identifier;
261 dev_name = strsep(&subvol_name, ":");
265 ret = btrfs_get_sb_bdev(fs_type, flags, dev_name, data,
266 btrfs_fill_super, mnt,
267 subvol_name ? subvol_name : "default");
272 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
274 struct btrfs_root *root = btrfs_sb(dentry->d_sb);
275 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
277 buf->f_namelen = BTRFS_NAME_LEN;
278 buf->f_blocks = btrfs_super_total_blocks(disk_super);
279 buf->f_bfree = buf->f_blocks - btrfs_super_blocks_used(disk_super);
280 buf->f_bavail = buf->f_bfree;
281 buf->f_bsize = dentry->d_sb->s_blocksize;
282 buf->f_type = BTRFS_SUPER_MAGIC;
286 static struct file_system_type btrfs_fs_type = {
287 .owner = THIS_MODULE,
289 .get_sb = btrfs_get_sb,
290 .kill_sb = kill_block_super,
291 .fs_flags = FS_REQUIRES_DEV,
294 static struct super_operations btrfs_super_ops = {
295 .delete_inode = btrfs_delete_inode,
296 .put_super = btrfs_put_super,
297 .read_inode = btrfs_read_locked_inode,
298 .write_super = btrfs_write_super,
299 .sync_fs = btrfs_sync_fs,
300 .write_inode = btrfs_write_inode,
301 .dirty_inode = btrfs_dirty_inode,
302 .alloc_inode = btrfs_alloc_inode,
303 .destroy_inode = btrfs_destroy_inode,
304 .statfs = btrfs_statfs,
307 static int __init init_btrfs_fs(void)
311 err = btrfs_init_sysfs();
315 btrfs_init_transaction_sys();
316 err = btrfs_init_cachep();
320 return register_filesystem(&btrfs_fs_type);
323 static void __exit exit_btrfs_fs(void)
325 btrfs_exit_transaction_sys();
326 btrfs_destroy_cachep();
328 unregister_filesystem(&btrfs_fs_type);
332 module_init(init_btrfs_fs)
333 module_exit(exit_btrfs_fs)
335 MODULE_LICENSE("GPL");