int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info);
int btrfs_run_dev_replace(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info);
-void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info);
int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info,
struct btrfs_ioctl_dev_replace_args *args);
int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info,