// AttachFileDevice takes a path to a regular file and makes it available as an
	// attached block device.
	AttachFileDevice(path string) (string, error)
	// DetachFileDevice takes a path to the attached block device and
	// detach it from block device.
	DetachFileDevice(path string) error
	// GetLoopDevice returns the full path to the loop device associated with the given path.
	GetLoopDevice(path string) (string, error)
}

	globalUnmapPath,
	podDeviceUnmapPath,
	volumeMapName string,
	podUID utypes.UID,
) error {
	// Release file descriptor lock.
	err := blkUtil.DetachFileDevice(filepath.Join(globalUnmapPath, string(podUID)))
	if err != nil {
		return fmt.Errorf("blkUtil.DetachFileDevice failed. globalUnmapPath:%s, podUID: %s: %v",
			globalUnmapPath, string(podUID), err)
	}

	// unmap devicePath from pod volume path