func NewHostUtil() *HostUtil {
	return &HostUtil{}
}

// DeviceOpened checks if block device in use by calling Open with O_EXCL flag.
// If pathname is not a device, log and return false with nil error.
// If open returns errno EBUSY, return true with nil error.
// If open returns nil, return false with nil error.
// Otherwise, return false with error
func (hu *HostUtil) DeviceOpened(pathname string) (bool, error) {