Included resizing for CSI-based block volumes.

Perform a no-op when volume is of type raw block

Fix bug with checking volume mounts for readonly

pkg/kubelet/volumemanager/populator/desired_state_of_world_populator.go

@@ -35,7 +35,6 @@ import (
 	"k8s.io/apimachinery/pkg/util/wait"
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	clientset "k8s.io/client-go/kubernetes"
-	podutil "k8s.io/kubernetes/pkg/api/v1/pod"
 	"k8s.io/kubernetes/pkg/features"
 	"k8s.io/kubernetes/pkg/kubelet/config"
 	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
@@ -384,16 +383,6 @@ func (dswp *desiredStateOfWorldPopulator) checkVolumeFSResize(
 		// or online resize in subsequent loop(after we confirm it has been mounted).
 		return
 	}
-	fsVolume, err := util.CheckVolumeModeFilesystem(volumeSpec)
-	if err != nil {
-		klog.Errorf("Check volume mode failed for volume %s(OuterVolumeSpecName %s): %v",
-			uniqueVolumeName, podVolume.Name, err)
-		return
-	}
-	if !fsVolume {
-		klog.V(5).Infof("Block mode volume needn't to check file system resize request")
-		return
-	}
 	if processedVolumesForFSResize.Has(string(uniqueVolumeName)) {
 		// File system resize operation is a global operation for volume,
 		// so we only need to check it once if more than one pod use it.
@@ -415,22 +404,7 @@ func mountedReadOnlyByPod(podVolume v1.Volume, pod *v1.Pod) bool {
 	if podVolume.PersistentVolumeClaim.ReadOnly {
 		return true
 	}
-
+	return false
-	return podutil.VisitContainers(&pod.Spec, func(c *v1.Container) bool {
-		if !mountedReadOnlyByContainer(podVolume.Name, c) {
-			return false
-		}
-		return true
-	})
-}
-
-func mountedReadOnlyByContainer(volumeName string, container *v1.Container) bool {
-	for _, volumeMount := range container.VolumeMounts {
-		if volumeMount.Name == volumeName && !volumeMount.ReadOnly {
-			return false
-		}
-	}
-	return true
 }
 
 func getUniqueVolumeName(

pkg/kubelet/volumemanager/populator/desired_state_of_world_populator_test.go

@@ -568,8 +568,6 @@ func TestCreateVolumeSpec_Invalid_Block_VolumeMounts(t *testing.T) {
 }
 
 func TestCheckVolumeFSResize(t *testing.T) {
-	mode := v1.PersistentVolumeFilesystem
-
 	setCapacity := func(pv *v1.PersistentVolume, pvc *v1.PersistentVolumeClaim, capacity int) {
 		pv.Spec.Capacity = volumeCapacity(capacity)
 		pvc.Spec.Resources.Requests = volumeCapacity(capacity)
@@ -580,6 +578,7 @@ func TestCheckVolumeFSResize(t *testing.T) {
 		verify       func(*testing.T, []v1.UniqueVolumeName, v1.UniqueVolumeName)
 		enableResize bool
 		readOnlyVol  bool
+		volumeMode   v1.PersistentVolumeMode
 	}{
 		{
 			// No resize request for volume, volumes in ASW shouldn't be marked as fsResizeRequired
@@ -591,6 +590,7 @@ func TestCheckVolumeFSResize(t *testing.T) {
 				}
 			},
 			enableResize: true,
+			volumeMode:   v1.PersistentVolumeFilesystem,
 		},
 		{
 			// Disable the feature gate, so volume shouldn't be marked as fsResizeRequired
@@ -603,6 +603,7 @@ func TestCheckVolumeFSResize(t *testing.T) {
 				}
 			},
 			enableResize: false,
+			volumeMode:   v1.PersistentVolumeFilesystem,
 		},
 		{
 			// Make volume used as ReadOnly, so volume shouldn't be marked as fsResizeRequired
@@ -616,6 +617,7 @@ func TestCheckVolumeFSResize(t *testing.T) {
 			},
 			readOnlyVol:  true,
 			enableResize: true,
+			volumeMode:   v1.PersistentVolumeFilesystem,
 		},
 		{
 			// Clear ASW, so volume shouldn't be marked as fsResizeRequired because they are not mounted
@@ -629,6 +631,7 @@ func TestCheckVolumeFSResize(t *testing.T) {
 				}
 			},
 			enableResize: true,
+			volumeMode:   v1.PersistentVolumeFilesystem,
 		},
 		{
 			// volume in ASW should be marked as fsResizeRequired
@@ -647,6 +650,26 @@ func TestCheckVolumeFSResize(t *testing.T) {
 				}
 			},
 			enableResize: true,
+			volumeMode:   v1.PersistentVolumeFilesystem,
+		},
+		{
+			// volume in ASW should be marked as fsResizeRequired
+			resize: func(_ *testing.T, pv *v1.PersistentVolume, pvc *v1.PersistentVolumeClaim, _ *desiredStateOfWorldPopulator) {
+				setCapacity(pv, pvc, 2)
+			},
+			verify: func(t *testing.T, vols []v1.UniqueVolumeName, volName v1.UniqueVolumeName) {
+				if len(vols) == 0 {
+					t.Fatalf("Request resize for volume, but volume in ASW hasn't been marked as fsResizeRequired")
+				}
+				if len(vols) != 1 {
+					t.Errorf("Some unexpected volumes are marked as fsResizeRequired: %v", vols)
+				}
+				if vols[0] != volName {
+					t.Fatalf("Mark wrong volume as fsResizeRequired: %s", vols[0])
+				}
+			},
+			enableResize: true,
+			volumeMode:   v1.PersistentVolumeBlock,
 		},
 	}
 
@@ -659,7 +682,7 @@ func TestCheckVolumeFSResize(t *testing.T) {
 				PersistentVolumeSource: v1.PersistentVolumeSource{RBD: &v1.RBDPersistentVolumeSource{}},
 				Capacity:               volumeCapacity(1),
 				ClaimRef:               &v1.ObjectReference{Namespace: "ns", Name: "file-bound"},
-				VolumeMode:             &mode,
+				VolumeMode:             &tc.volumeMode,
 			},
 		}
 		pvc := &v1.PersistentVolumeClaim{
@@ -677,10 +700,10 @@ func TestCheckVolumeFSResize(t *testing.T) {
 
 		dswp, fakePodManager, fakeDSW := createDswpWithVolume(t, pv, pvc)
 		fakeASW := dswp.actualStateOfWorld
+		containers := []v1.Container{}
 
-		// create pod
+		if tc.volumeMode == v1.PersistentVolumeFilesystem {
-		containers := []v1.Container{
+			containers = append(containers, v1.Container{
-			{
 				VolumeMounts: []v1.VolumeMount{
 					{
 						Name:      pv.Name,
@@ -688,9 +711,20 @@ func TestCheckVolumeFSResize(t *testing.T) {
 						ReadOnly:  tc.readOnlyVol,
 					},
 				},
-			},
+			})
+		} else {
+			containers = append(containers, v1.Container{
+				VolumeDevices: []v1.VolumeDevice{
+					{
+						Name:       pv.Name,
+						DevicePath: "/mnt/foobar",
+					},
+				},
+			})
 		}
+
 		pod := createPodWithVolume("dswp-test-pod", "dswp-test-volume-name", "file-bound", containers)
+		pod.Spec.Volumes[0].VolumeSource.PersistentVolumeClaim.ReadOnly = tc.readOnlyVol
 		uniquePodName := types.UniquePodName(pod.UID)
 		uniqueVolumeName := v1.UniqueVolumeName("fake-plugin/" + pod.Spec.Volumes[0].Name)
 

pkg/volume/awsebs/aws_ebs.go

@@ -324,7 +324,15 @@ func (plugin *awsElasticBlockStorePlugin) ExpandVolumeDevice(
 }
 
 func (plugin *awsElasticBlockStorePlugin) NodeExpand(resizeOptions volume.NodeResizeOptions) (bool, error) {
-	_, err := util.GenericResizeFS(plugin.host, plugin.GetPluginName(), resizeOptions.DevicePath, resizeOptions.DeviceMountPath)
+	fsVolume, err := util.CheckVolumeModeFilesystem(resizeOptions.VolumeSpec)
+	if err != nil {
+		return false, fmt.Errorf("error checking VolumeMode: %v", err)
+	}
+	// if volume is not a fs file system, there is nothing for us to do here.
+	if !fsVolume {
+		return true, nil
+	}
+	_, err = util.GenericResizeFS(plugin.host, plugin.GetPluginName(), resizeOptions.DevicePath, resizeOptions.DeviceMountPath)
 	if err != nil {
 		return false, err
 	}

pkg/volume/azure_dd/azure_dd.go

@@ -298,7 +298,15 @@ func (plugin *azureDataDiskPlugin) ExpandVolumeDevice(
 }
 
 func (plugin *azureDataDiskPlugin) NodeExpand(resizeOptions volume.NodeResizeOptions) (bool, error) {
-	_, err := util.GenericResizeFS(plugin.host, plugin.GetPluginName(), resizeOptions.DevicePath, resizeOptions.DeviceMountPath)
+	fsVolume, err := util.CheckVolumeModeFilesystem(resizeOptions.VolumeSpec)
+	if err != nil {
+		return false, fmt.Errorf("error checking VolumeMode: %v", err)
+	}
+	// if volume is not a fs file system, there is nothing for us to do here.
+	if !fsVolume {
+		return true, nil
+	}
+	_, err = util.GenericResizeFS(plugin.host, plugin.GetPluginName(), resizeOptions.DevicePath, resizeOptions.DeviceMountPath)
 	if err != nil {
 		return false, err
 	}

pkg/volume/cinder/cinder.go

@@ -311,7 +311,16 @@ func (plugin *cinderPlugin) ExpandVolumeDevice(spec *volume.Spec, newSize resour
 }
 
 func (plugin *cinderPlugin) NodeExpand(resizeOptions volume.NodeResizeOptions) (bool, error) {
-	_, err := util.GenericResizeFS(plugin.host, plugin.GetPluginName(), resizeOptions.DevicePath, resizeOptions.DeviceMountPath)
+	fsVolume, err := util.CheckVolumeModeFilesystem(resizeOptions.VolumeSpec)
+	if err != nil {
+		return false, fmt.Errorf("error checking VolumeMode: %v", err)
+	}
+	// if volume is not a fs file system, there is nothing for us to do here.
+	if !fsVolume {
+		return true, nil
+	}
+
+	_, err = util.GenericResizeFS(plugin.host, plugin.GetPluginName(), resizeOptions.DevicePath, resizeOptions.DeviceMountPath)
 	if err != nil {
 		return false, err
 	}

pkg/volume/flexvolume/expander-defaults.go

@@ -17,6 +17,8 @@ limitations under the License.
 package flexvolume
 
 import (
+	"fmt"
+
 	"k8s.io/apimachinery/pkg/api/resource"
 	"k8s.io/klog"
 	"k8s.io/kubernetes/pkg/volume"
@@ -40,7 +42,16 @@ func (e *expanderDefaults) ExpandVolumeDevice(spec *volume.Spec, newSize resourc
 // generic filesystem resize
 func (e *expanderDefaults) NodeExpand(rsOpt volume.NodeResizeOptions) (bool, error) {
 	klog.Warning(logPrefix(e.plugin), "using default filesystem resize for volume ", rsOpt.VolumeSpec.Name(), ", at ", rsOpt.DevicePath)
-	_, err := util.GenericResizeFS(e.plugin.host, e.plugin.GetPluginName(), rsOpt.DevicePath, rsOpt.DeviceMountPath)
+	fsVolume, err := util.CheckVolumeModeFilesystem(rsOpt.VolumeSpec)
+	if err != nil {
+		return false, fmt.Errorf("error checking VolumeMode: %v", err)
+	}
+	// if volume is not a fs file system, there is nothing for us to do here.
+	if !fsVolume {
+		return true, nil
+	}
+
+	_, err = util.GenericResizeFS(e.plugin.host, e.plugin.GetPluginName(), rsOpt.DevicePath, rsOpt.DeviceMountPath)
 	if err != nil {
 		return false, err
 	}

pkg/volume/gcepd/gce_pd.go

@@ -280,7 +280,15 @@ func (plugin *gcePersistentDiskPlugin) ExpandVolumeDevice(
 }
 
 func (plugin *gcePersistentDiskPlugin) NodeExpand(resizeOptions volume.NodeResizeOptions) (bool, error) {
-	_, err := util.GenericResizeFS(plugin.host, plugin.GetPluginName(), resizeOptions.DevicePath, resizeOptions.DeviceMountPath)
+	fsVolume, err := util.CheckVolumeModeFilesystem(resizeOptions.VolumeSpec)
+	if err != nil {
+		return false, fmt.Errorf("error checking VolumeMode: %v", err)
+	}
+	// if volume is not a fs file system, there is nothing for us to do here.
+	if !fsVolume {
+		return true, nil
+	}
+	_, err = util.GenericResizeFS(plugin.host, plugin.GetPluginName(), resizeOptions.DevicePath, resizeOptions.DeviceMountPath)
 	if err != nil {
 		return false, err
 	}

pkg/volume/rbd/rbd.go

@@ -35,6 +35,7 @@ import (
 	"k8s.io/kubernetes/pkg/features"
 	"k8s.io/kubernetes/pkg/util/mount"
 	"k8s.io/kubernetes/pkg/volume"
+	"k8s.io/kubernetes/pkg/volume/util"
 	volutil "k8s.io/kubernetes/pkg/volume/util"
 	"k8s.io/kubernetes/pkg/volume/util/volumepathhandler"
 	utilstrings "k8s.io/utils/strings"
@@ -202,7 +203,15 @@ func (plugin *rbdPlugin) ExpandVolumeDevice(spec *volume.Spec, newSize resource.
 }
 
 func (plugin *rbdPlugin) NodeExpand(resizeOptions volume.NodeResizeOptions) (bool, error) {
-	_, err := volutil.GenericResizeFS(plugin.host, plugin.GetPluginName(), resizeOptions.DevicePath, resizeOptions.DeviceMountPath)
+	fsVolume, err := util.CheckVolumeModeFilesystem(resizeOptions.VolumeSpec)
+	if err != nil {
+		return false, fmt.Errorf("error checking VolumeMode: %v", err)
+	}
+	// if volume is not a fs file system, there is nothing for us to do here.
+	if !fsVolume {
+		return true, nil
+	}
+	_, err = volutil.GenericResizeFS(plugin.host, plugin.GetPluginName(), resizeOptions.DevicePath, resizeOptions.DeviceMountPath)
 	if err != nil {
 		return false, err
 	}

pkg/volume/util/operationexecutor/BUILD

@@ -12,6 +12,7 @@ go_library(
         "fakegenerator.go",
         "operation_executor.go",
         "operation_generator.go",
+        "volume_operation.go",
     ],
     importpath = "k8s.io/kubernetes/pkg/volume/util/operationexecutor",
     deps = [

pkg/volume/util/operationexecutor/operation_generator.go

@@ -707,12 +707,12 @@ func (og *operationGenerator) GenerateMountVolumeFunc(
 			resizeOptions.DeviceMountPath = deviceMountPath
 			resizeOptions.CSIVolumePhase = volume.CSIVolumeStaged
 
-			// resizeFileSystem will resize the file system if user has requested a resize of
+			// NodeExpandVolume will resize the file system if user has requested a resize of
 			// underlying persistent volume and is allowed to do so.
-			resizeDone, resizeError = og.resizeFileSystem(volumeToMount, resizeOptions)
+			resizeDone, resizeError = og.nodeExpandVolume(volumeToMount, resizeOptions)
 
 			if resizeError != nil {
-				klog.Errorf("MountVolume.resizeFileSystem failed with %v", resizeError)
+				klog.Errorf("MountVolume.NodeExpandVolume failed with %v", resizeError)
 				return volumeToMount.GenerateError("MountVolume.MountDevice failed while expanding volume", resizeError)
 			}
 		}
@@ -750,9 +750,9 @@ func (og *operationGenerator) GenerateMountVolumeFunc(
 		//	- Volume does not support DeviceMounter interface.
 		//	- In case of CSI the volume does not have node stage_unstage capability.
 		if !resizeDone {
-			resizeDone, resizeError = og.resizeFileSystem(volumeToMount, resizeOptions)
+			resizeDone, resizeError = og.nodeExpandVolume(volumeToMount, resizeOptions)
 			if resizeError != nil {
-				klog.Errorf("MountVolume.resizeFileSystem failed with %v", resizeError)
+				klog.Errorf("MountVolume.NodeExpandVolume failed with %v", resizeError)
 				return volumeToMount.GenerateError("MountVolume.Setup failed while expanding volume", resizeError)
 			}
 		}
@@ -789,72 +789,6 @@ func (og *operationGenerator) GenerateMountVolumeFunc(
 	}
 }
 
-func (og *operationGenerator) resizeFileSystem(volumeToMount VolumeToMount, rsOpts volume.NodeResizeOptions) (bool, error) {
-	if !utilfeature.DefaultFeatureGate.Enabled(features.ExpandPersistentVolumes) {
-		klog.V(4).Infof("Resizing is not enabled for this volume %s", volumeToMount.VolumeName)
-		return true, nil
-	}
-
-	if volumeToMount.VolumeSpec != nil &&
-		volumeToMount.VolumeSpec.InlineVolumeSpecForCSIMigration {
-		klog.V(4).Infof("This volume %s is a migrated inline volume and is not resizable", volumeToMount.VolumeName)
-		return true, nil
-	}
-
-	// Get expander, if possible
-	expandableVolumePlugin, _ :=
-		og.volumePluginMgr.FindNodeExpandablePluginBySpec(volumeToMount.VolumeSpec)
-
-	if expandableVolumePlugin != nil &&
-		expandableVolumePlugin.RequiresFSResize() &&
-		volumeToMount.VolumeSpec.PersistentVolume != nil {
-		pv := volumeToMount.VolumeSpec.PersistentVolume
-		pvc, err := og.kubeClient.CoreV1().PersistentVolumeClaims(pv.Spec.ClaimRef.Namespace).Get(pv.Spec.ClaimRef.Name, metav1.GetOptions{})
-		if err != nil {
-			// Return error rather than leave the file system un-resized, caller will log and retry
-			return false, fmt.Errorf("MountVolume.resizeFileSystem get PVC failed : %v", err)
-		}
-
-		pvcStatusCap := pvc.Status.Capacity[v1.ResourceStorage]
-		pvSpecCap := pv.Spec.Capacity[v1.ResourceStorage]
-		if pvcStatusCap.Cmp(pvSpecCap) < 0 {
-			// File system resize was requested, proceed
-			klog.V(4).Infof(volumeToMount.GenerateMsgDetailed("MountVolume.resizeFileSystem entering", fmt.Sprintf("DevicePath %q", volumeToMount.DevicePath)))
-
-			if volumeToMount.VolumeSpec.ReadOnly {
-				simpleMsg, detailedMsg := volumeToMount.GenerateMsg("MountVolume.resizeFileSystem failed", "requested read-only file system")
-				klog.Warningf(detailedMsg)
-				og.recorder.Eventf(volumeToMount.Pod, v1.EventTypeWarning, kevents.FileSystemResizeFailed, simpleMsg)
-				return true, nil
-			}
-			rsOpts.VolumeSpec = volumeToMount.VolumeSpec
-			rsOpts.NewSize = pvSpecCap
-			rsOpts.OldSize = pvcStatusCap
-			resizeDone, resizeErr := expandableVolumePlugin.NodeExpand(rsOpts)
-			if resizeErr != nil {
-				return false, fmt.Errorf("MountVolume.resizeFileSystem failed : %v", resizeErr)
-			}
-			// Volume resizing is not done but it did not error out. This could happen if a CSI volume
-			// does not have node stage_unstage capability but was asked to resize the volume before
-			// node publish. In which case - we must retry resizing after node publish.
-			if !resizeDone {
-				return false, nil
-			}
-			simpleMsg, detailedMsg := volumeToMount.GenerateMsg("MountVolume.resizeFileSystem succeeded", "")
-			og.recorder.Eventf(volumeToMount.Pod, v1.EventTypeNormal, kevents.FileSystemResizeSuccess, simpleMsg)
-			klog.Infof(detailedMsg)
-			// File system resize succeeded, now update the PVC's Capacity to match the PV's
-			err = util.MarkFSResizeFinished(pvc, pvSpecCap, og.kubeClient)
-			if err != nil {
-				// On retry, resizeFileSystem will be called again but do nothing
-				return false, fmt.Errorf("MountVolume.resizeFileSystem update PVC status failed : %v", err)
-			}
-			return true, nil
-		}
-	}
-	return true, nil
-}
-
 func (og *operationGenerator) GenerateUnmountVolumeFunc(
 	volumeToUnmount MountedVolume,
 	actualStateOfWorld ActualStateOfWorldMounterUpdater,
@@ -1165,6 +1099,16 @@ func (og *operationGenerator) GenerateMapVolumeFunc(
 		og.recorder.Eventf(volumeToMount.Pod, v1.EventTypeNormal, kevents.SuccessfulMountVolume, simpleMsg)
 		klog.V(verbosity).Infof(detailedMsg)
 
+		resizeOptions := volume.NodeResizeOptions{
+			DevicePath:     devicePath,
+			CSIVolumePhase: volume.CSIVolumePublished,
+		}
+		_, resizeError := og.nodeExpandVolume(volumeToMount, resizeOptions)
+		if resizeError != nil {
+			klog.Errorf("MapVolume.NodeExpandVolume failed with %v", resizeError)
+			return volumeToMount.GenerateError("MapVolume.MarkVolumeAsMounted failed while expanding volume", resizeError)
+		}
+
 		// Update actual state of world
 		markVolMountedErr := actualStateOfWorld.MarkVolumeAsMounted(
 			volumeToMount.PodName,
@@ -1623,14 +1567,14 @@ func (og *operationGenerator) GenerateExpandInUseVolumeFunc(
 		if useCSIPlugin(og.volumePluginMgr, volumeToMount.VolumeSpec) {
 			csiSpec, err := translateSpec(volumeToMount.VolumeSpec)
 			if err != nil {
-				return volumeToMount.GenerateError("VolumeFSResize.translateSpec failed", err)
+				return volumeToMount.GenerateError("NodeExpandVolume.translateSpec failed", err)
 			}
 			volumeToMount.VolumeSpec = csiSpec
 		}
 		volumePlugin, err :=
 			og.volumePluginMgr.FindPluginBySpec(volumeToMount.VolumeSpec)
 		if err != nil || volumePlugin == nil {
-			return volumeToMount.GenerateError("VolumeFSResize.FindPluginBySpec failed", err)
+			return volumeToMount.GenerateError("NodeExpandVolume.FindPluginBySpec failed", err)
 		}
 
 		var resizeDone bool
@@ -1649,7 +1593,7 @@ func (og *operationGenerator) GenerateExpandInUseVolumeFunc(
 				resizeOptions.DevicePath = volumeToMount.DevicePath
 				dmp, err := volumeAttacher.GetDeviceMountPath(volumeToMount.VolumeSpec)
 				if err != nil {
-					return volumeToMount.GenerateError("VolumeFSResize.GetDeviceMountPath failed", err)
+					return volumeToMount.GenerateError("NodeExpandVolume.GetDeviceMountPath failed", err)
 				}
 				resizeOptions.DeviceMountPath = dmp
 				resizeDone, simpleErr, detailedErr = og.doOnlineExpansion(volumeToMount, actualStateOfWorld, resizeOptions)
@@ -1667,7 +1611,7 @@ func (og *operationGenerator) GenerateExpandInUseVolumeFunc(
 			volumeToMount.Pod,
 			volume.VolumeOptions{})
 		if newMounterErr != nil {
-			return volumeToMount.GenerateError("VolumeFSResize.NewMounter initialization failed", newMounterErr)
+			return volumeToMount.GenerateError("NodeExpandVolume.NewMounter initialization failed", newMounterErr)
 		}
 
 		resizeOptions.DeviceMountPath = volumeMounter.GetPath()
@@ -1681,7 +1625,7 @@ func (og *operationGenerator) GenerateExpandInUseVolumeFunc(
 		}
 		// This is a placeholder error - we should NEVER reach here.
 		err = fmt.Errorf("volume resizing failed for unknown reason")
-		return volumeToMount.GenerateError("VolumeFSResize.resizeFileSystem failed to resize volume", err)
+		return volumeToMount.GenerateError("NodeExpandVolume.NodeExpandVolume failed to resize volume", err)
 	}
 
 	eventRecorderFunc := func(err *error) {
@@ -1705,7 +1649,7 @@ func (og *operationGenerator) GenerateExpandInUseVolumeFunc(
 	volumePlugin, err :=
 		og.volumePluginMgr.FindPluginBySpec(volumeToMount.VolumeSpec)
 	if err != nil || volumePlugin == nil {
-		return volumetypes.GeneratedOperations{}, volumeToMount.GenerateErrorDetailed("VolumeFSResize.FindPluginBySpec failed", err)
+		return volumetypes.GeneratedOperations{}, volumeToMount.GenerateErrorDetailed("NodeExpandVolume.FindPluginBySpec failed", err)
 	}
 
 	return volumetypes.GeneratedOperations{
@@ -1719,17 +1663,18 @@ func (og *operationGenerator) GenerateExpandInUseVolumeFunc(
 func (og *operationGenerator) doOnlineExpansion(volumeToMount VolumeToMount,
 	actualStateOfWorld ActualStateOfWorldMounterUpdater,
 	resizeOptions volume.NodeResizeOptions) (bool, error, error) {
-	resizeDone, err := og.resizeFileSystem(volumeToMount, resizeOptions)
+
+	resizeDone, err := og.nodeExpandVolume(volumeToMount, resizeOptions)
 	if err != nil {
-		klog.Errorf("VolumeFSResize.resizeFileSystem failed : %v", err)
+		klog.Errorf("NodeExpandVolume.NodeExpandVolume failed : %v", err)
-		e1, e2 := volumeToMount.GenerateError("VolumeFSResize.resizeFileSystem failed", err)
+		e1, e2 := volumeToMount.GenerateError("NodeExpandVolume.NodeExpandVolume failed", err)
 		return false, e1, e2
 	}
 	if resizeDone {
 		markFSResizedErr := actualStateOfWorld.MarkVolumeAsResized(volumeToMount.PodName, volumeToMount.VolumeName)
 		if markFSResizedErr != nil {
 			// On failure, return error. Caller will log and retry.
-			e1, e2 := volumeToMount.GenerateError("VolumeFSResize.MarkVolumeAsResized failed", markFSResizedErr)
+			e1, e2 := volumeToMount.GenerateError("NodeExpandVolume.MarkVolumeAsResized failed", markFSResizedErr)
 			return false, e1, e2
 		}
 		return true, nil, nil
@@ -1737,6 +1682,72 @@ func (og *operationGenerator) doOnlineExpansion(volumeToMount VolumeToMount,
 	return false, nil, nil
 }
 
+func (og *operationGenerator) nodeExpandVolume(volumeToMount VolumeToMount, rsOpts volume.NodeResizeOptions) (bool, error) {
+	if !utilfeature.DefaultFeatureGate.Enabled(features.ExpandPersistentVolumes) {
+		klog.V(4).Infof("Resizing is not enabled for this volume %s", volumeToMount.VolumeName)
+		return true, nil
+	}
+
+	if volumeToMount.VolumeSpec != nil &&
+		volumeToMount.VolumeSpec.InlineVolumeSpecForCSIMigration {
+		klog.V(4).Infof("This volume %s is a migrated inline volume and is not resizable", volumeToMount.VolumeName)
+		return true, nil
+	}
+
+	// Get expander, if possible
+	expandableVolumePlugin, _ :=
+		og.volumePluginMgr.FindNodeExpandablePluginBySpec(volumeToMount.VolumeSpec)
+
+	if expandableVolumePlugin != nil &&
+		expandableVolumePlugin.RequiresFSResize() &&
+		volumeToMount.VolumeSpec.PersistentVolume != nil {
+		pv := volumeToMount.VolumeSpec.PersistentVolume
+		pvc, err := og.kubeClient.CoreV1().PersistentVolumeClaims(pv.Spec.ClaimRef.Namespace).Get(pv.Spec.ClaimRef.Name, metav1.GetOptions{})
+		if err != nil {
+			// Return error rather than leave the file system un-resized, caller will log and retry
+			return false, fmt.Errorf("MountVolume.NodeExpandVolume get PVC failed : %v", err)
+		}
+
+		pvcStatusCap := pvc.Status.Capacity[v1.ResourceStorage]
+		pvSpecCap := pv.Spec.Capacity[v1.ResourceStorage]
+		if pvcStatusCap.Cmp(pvSpecCap) < 0 {
+			// File system resize was requested, proceed
+			klog.V(4).Infof(volumeToMount.GenerateMsgDetailed("MountVolume.NodeExpandVolume entering", fmt.Sprintf("DevicePath %q", volumeToMount.DevicePath)))
+
+			if volumeToMount.VolumeSpec.ReadOnly {
+				simpleMsg, detailedMsg := volumeToMount.GenerateMsg("MountVolume.NodeExpandVolume failed", "requested read-only file system")
+				klog.Warningf(detailedMsg)
+				og.recorder.Eventf(volumeToMount.Pod, v1.EventTypeWarning, kevents.FileSystemResizeFailed, simpleMsg)
+				return true, nil
+			}
+			rsOpts.VolumeSpec = volumeToMount.VolumeSpec
+			rsOpts.NewSize = pvSpecCap
+			rsOpts.OldSize = pvcStatusCap
+			resizeDone, resizeErr := expandableVolumePlugin.NodeExpand(rsOpts)
+			if resizeErr != nil {
+				return false, fmt.Errorf("MountVolume.NodeExpandVolume failed : %v", resizeErr)
+			}
+			// Volume resizing is not done but it did not error out. This could happen if a CSI volume
+			// does not have node stage_unstage capability but was asked to resize the volume before
+			// node publish. In which case - we must retry resizing after node publish.
+			if !resizeDone {
+				return false, nil
+			}
+			simpleMsg, detailedMsg := volumeToMount.GenerateMsg("MountVolume.NodeExpandVolume succeeded", "")
+			og.recorder.Eventf(volumeToMount.Pod, v1.EventTypeNormal, kevents.FileSystemResizeSuccess, simpleMsg)
+			klog.Infof(detailedMsg)
+			// File system resize succeeded, now update the PVC's Capacity to match the PV's
+			err = util.MarkFSResizeFinished(pvc, pvSpecCap, og.kubeClient)
+			if err != nil {
+				// On retry, NodeExpandVolume will be called again but do nothing
+				return false, fmt.Errorf("MountVolume.NodeExpandVolume update PVC status failed : %v", err)
+			}
+			return true, nil
+		}
+	}
+	return true, nil
+}
+
 func checkMountOptionSupport(og *operationGenerator, volumeToMount VolumeToMount, plugin volume.VolumePlugin) error {
 	mountOptions := util.MountOptionFromSpec(volumeToMount.VolumeSpec)