Supply staging path for block expansion

pkg/volume/csi/csi_block.go

@@ -255,26 +255,26 @@ func (m *csiBlockMapper) publishVolumeForBlock(
 }
 
 // SetUpDevice ensures the device is attached returns path where the device is located.
-func (m *csiBlockMapper) SetUpDevice() error {
+func (m *csiBlockMapper) SetUpDevice() (string, error) {
 	if !m.plugin.blockEnabled {
-		return errors.New("CSIBlockVolume feature not enabled")
+		return "", errors.New("CSIBlockVolume feature not enabled")
 	}
 	klog.V(4).Infof(log("blockMapper.SetUpDevice called"))
 
 	// Get csiSource from spec
 	if m.spec == nil {
-		return errors.New(log("blockMapper.SetUpDevice spec is nil"))
+		return "", errors.New(log("blockMapper.SetUpDevice spec is nil"))
 	}
 
 	csiSource, err := getCSISourceFromSpec(m.spec)
 	if err != nil {
-		return errors.New(log("blockMapper.SetUpDevice failed to get CSI persistent source: %v", err))
+		return "", errors.New(log("blockMapper.SetUpDevice failed to get CSI persistent source: %v", err))
 	}
 
 	driverName := csiSource.Driver
 	skip, err := m.plugin.skipAttach(driverName)
 	if err != nil {
-		return errors.New(log("blockMapper.SetupDevice failed to check CSIDriver for %s: %v", driverName, err))
+		return "", errors.New(log("blockMapper.SetupDevice failed to check CSIDriver for %s: %v", driverName, err))
 	}
 
 	var attachment *storage.VolumeAttachment
@@ -284,7 +284,7 @@ func (m *csiBlockMapper) SetUpDevice() error {
 		attachID := getAttachmentName(csiSource.VolumeHandle, csiSource.Driver, nodeName)
 		attachment, err = m.k8s.StorageV1().VolumeAttachments().Get(context.TODO(), attachID, meta.GetOptions{})
 		if err != nil {
-			return errors.New(log("blockMapper.SetupDevice failed to get volume attachment [id=%v]: %v", attachID, err))
+			return "", errors.New(log("blockMapper.SetupDevice failed to get volume attachment [id=%v]: %v", attachID, err))
 		}
 	}
 
@@ -299,11 +299,11 @@ func (m *csiBlockMapper) SetUpDevice() error {
 
 	csiClient, err := m.csiClientGetter.Get()
 	if err != nil {
-		return errors.New(log("blockMapper.SetUpDevice failed to get CSI client: %v", err))
+		return "", errors.New(log("blockMapper.SetUpDevice failed to get CSI client: %v", err))
 	}
 
 	// Call NodeStageVolume
-	_, err = m.stageVolumeForBlock(ctx, csiClient, accessMode, csiSource, attachment)
+	stagingPath, err := m.stageVolumeForBlock(ctx, csiClient, accessMode, csiSource, attachment)
 	if err != nil {
 		if volumetypes.IsOperationFinishedError(err) {
 			cleanupErr := m.cleanupOrphanDeviceFiles()
@@ -312,10 +312,10 @@ func (m *csiBlockMapper) SetUpDevice() error {
 				klog.V(4).Infof("Failed to clean up block volume directory %s", cleanupErr)
 			}
 		}
-		return err
+		return "", err
 	}
 
-	return nil
+	return stagingPath, nil
 }
 
 func (m *csiBlockMapper) MapPodDevice() (string, error) {