CSI inline volumes should support fsGroup

pkg/volume/csi/csi_mounter.go

@@ -404,10 +404,7 @@ func (c *csiMountMgr) supportsFSGroup(fsType string, fsGroup *int64, driverPolic
 		return false
 	}
 
-	if c.spec.PersistentVolume == nil {
+	if c.spec.PersistentVolume != nil {
-		klog.V(4).Info(log("mounter.SetupAt Warning: skipping fsGroup permission change, no access mode available. The volume may only be accessible to root users."))
-		return false
-	}
 		if c.spec.PersistentVolume.Spec.AccessModes == nil {
 			klog.V(4).Info(log("mounter.SetupAt WARNING: skipping fsGroup, access modes not provided"))
 			return false
@@ -417,6 +414,17 @@ func (c *csiMountMgr) supportsFSGroup(fsType string, fsGroup *int64, driverPolic
 			return false
 		}
 		return true
+	} else if c.spec.Volume != nil && c.spec.Volume.CSI != nil {
+		if !utilfeature.DefaultFeatureGate.Enabled(features.CSIInlineVolume) {
+			klog.V(4).Info(log("mounter.SetupAt WARNING: skipping fsGroup, CSIInlineVolume feature required"))
+			return false
+		}
+		// Inline CSI volumes are always mounted with RWO AccessMode by SetUpAt
+		return true
+	}
+
+	klog.V(4).Info(log("mounter.SetupAt WARNING: skipping fsGroup, unsupported volume type"))
+	return false
 }
 
 // isDirMounted returns the !notMounted result from IsLikelyNotMountPoint check

pkg/volume/csi/csi_mounter_test.go

@@ -1201,6 +1201,24 @@ func Test_csiMountMgr_supportsFSGroup(t *testing.T) {
 			},
 			want: true,
 		},
+		{
+			name: "driverPolicy is ReadWriteOnceWithFSTypeFSGroupPolicy with CSI inline volume",
+			args: args{
+				fsGroup:      new(int64),
+				fsType:       "ext4",
+				driverPolicy: storage.ReadWriteOnceWithFSTypeFSGroupPolicy,
+			},
+			fields: fields{
+				spec: volume.NewSpecFromVolume(&api.Volume{
+					VolumeSource: api.VolumeSource{
+						CSI: &api.CSIVolumeSource{
+							Driver: testDriver,
+						},
+					},
+				}),
+			},
+			want: true,
+		},
 	}
 
 	for _, tt := range tests {