pub fn create_fs_device(
    protection_type: ProtectionType,
    jail_config: &Option<JailConfig>,
    ugid: (Option<u32>, Option<u32>),
    uid_map: &str,
    gid_map: &str,
    src: &Path,
    tag: &str,
    fs_cfg: Config,
    device_tube: Tube
) -> Result<VirtioDeviceStub>