convert btrfs

 * Note:  This is based on get_sb_bdev from fs/super.c with a few additions

 *	  for multiple device setup.  Make sure to keep it in sync.

 */

static int btrfs_get_sb(struct file_system_type *fs_type, int flags,

		const char *dev_name, void *data, struct vfsmount *mnt)

static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,

		const char *dev_name, void *data)

{

	struct block_device *bdev = NULL;

	struct super_block *s;

					  &subvol_name, &subvol_objectid,

					  &fs_devices);

	if (error)

		return error;

		return ERR_PTR(error);

	error = btrfs_scan_one_device(dev_name, mode, fs_type, &fs_devices);

	if (error)

		root = new_root;

	}

	mnt->mnt_sb = s;

	mnt->mnt_root = root;

	kfree(subvol_name);

	return 0;

	return root;

error_s:

	error = PTR_ERR(s);

error_free_subvol_name:

	kfree(subvol_name);

error:

	return error;

	return ERR_PTR(error);

}

static int btrfs_remount(struct super_block *sb, int *flags, char *data)

static struct file_system_type btrfs_fs_type = {

	.owner		= THIS_MODULE,

	.name		= "btrfs",

	.get_sb		= btrfs_get_sb,

	.mount		= btrfs_mount,

	.kill_sb	= kill_anon_super,

	.fs_flags	= FS_REQUIRES_DEV,

};