// mutex to prevent concurrent read operations overloading walks.
	rotational bool
	walkMu     *sync.Mutex
	walkReadMu *sync.Mutex
}

// checkPathLength - returns error if given path name length more than 255
func checkPathLength(pathName string) error {
	// Apple OS X path length is limited to 1016
	if runtime.GOOS == "darwin" && len(pathName) > 1016 {
		return errFileNameTooLong
	}