func getVolumeDeviceDataDir(specVolID string, host volume.VolumeHost) string {
	return filepath.Join(getVolumePluginDir(specVolID, host), "data")
}

// hasReadWriteOnce returns true if modes contains v1.ReadWriteOnce
func hasReadWriteOnce(modes []api.PersistentVolumeAccessMode) bool {
	if modes == nil {
		return false
	}
	for _, mode := range modes {
		if mode == api.ReadWriteOnce {
			return true
		}