if err != nil {
		return nil, err
	}

	readOnly, err := getReadOnly(spec)
	if err != nil {
		return nil, err
	}

	var metricsProvider volume.MetricsProvider
	if plugin.capabilities.SupportsMetrics {
		metricsProvider = volume.NewMetricsStatFS(plugin.host.GetPodVolumeDir(
			pod.UID, utilstrings.EscapeQualifiedName(sourceDriver), spec.Name()))
	} else {
		metricsProvider = &volume.MetricsNil{}
	}

	return globalPath, nil
}

// GetStagingPath returns
func (m *localVolumeMapper) GetStagingPath() string {
	return ""
}

// SupportsMetrics returns true for SupportsMetrics as it initializes the
// MetricsProvider.
func (m *localVolumeMapper) SupportsMetrics() bool {
	return true
}

// localVolumeUnmapper implements the BlockVolumeUnmapper interface for local volumes.
type localVolumeUnmapper struct {

	// ex. pods/{podUid}/{DefaultKubeletVolumeDevicesDirName}/{escapeQualifiedPluginName}/, {volumeName}
	GetPodDeviceMapPath() (string, string)

	// SupportsMetrics should return true if the MetricsProvider is
	// initialized
	SupportsMetrics() bool

	// MetricsProvider embeds methods for exposing metrics (e.g.
	// used, available space).
	MetricsProvider
}

type iscsiDiskUnmapper struct {
	*iscsiDisk
	exec       utilexec.Interface
	deviceUtil ioutil.DeviceUtil
	volume.MetricsNil
}

// SupportsMetrics returns true for SupportsMetrics as it initializes the
// MetricsProvider.
func (idm *iscsiDiskMapper) SupportsMetrics() bool {
	return true
}

var _ volume.BlockVolumeUnmapper = &iscsiDiskUnmapper{}
var _ volume.CustomBlockVolumeUnmapper = &iscsiDiskUnmapper{}

func (v *fakeBlockVolume) GetGlobalMapPath(*volume.Spec) (string, error) { return "", nil }

func (v *fakeBlockVolume) GetPodDeviceMapPath() (string, string) { return "", "" }

func (v *fakeBlockVolume) SupportsMetrics() bool { return true }

func (v *fakeBlockVolume) GetMetrics() (*volume.Metrics, error) {
	return expectedBlockMetrics(), nil
}

func expectedBlockMetrics() *volume.Metrics {
	vMetrics := &volume.Metrics{

func (m *csiBlockMapper) GetStagingPath() string {
	return filepath.Join(m.plugin.host.GetVolumeDevicePluginDir(CSIPluginName), "staging", m.specName)
}

// SupportsMetrics returns true for csiBlockMapper as it initializes the
// MetricsProvider.
func (m *csiBlockMapper) SupportsMetrics() bool {
	return true
}

// getPublishDir returns path to a directory, where the volume is published to each pod.