var mountpointMap = make(map[string]string)
var mountpointLock sync.RWMutex

var providers = []common.LinuxVolumeQuotaProvider{
	&common.VolumeProvider{},
}

// Separate the innards for ease of testing
func detectBackingDevInternal(mountpoint string, mounts string) (string, error) {
	file, err := os.Open(mounts)
	if err != nil {
		return "", err
	}
	defer file.Close()
	scanner := bufio.NewScanner(file)
	for scanner.Scan() {

	if err != nil {
		return err
	}
	defer os.Remove(tmpfile.Name())
	if _, err = tmpfile.WriteString(testcase.mountdata); err != nil {
		return err
	}

	backingDev, err := detectBackingDevInternal(testcase.path, tmpfile.Name())
	if err != nil {
		if testcase.expectFailure {
			return nil
		}
		return err
	}
	if testcase.expectFailure {