Fix mountoption issue in rbd

use mountoptions when mounting rbd to stagingpath
in stagevolume request, add E2E for mount options

fixes: #846
updates: #757

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

e2e/rbd.go

@@ -393,6 +393,14 @@ var _ = Describe("RBD", func() {
 				}
 			})
 
+			By("validate mount options in app pod", func() {
+				mountFlags := []string{"discard"}
+				err := checkMountOptions(pvcPath, appPath, f, mountFlags)
+				if err != nil {
+					Fail(err.Error())
+				}
+			})
+
 			// Make sure this should be last testcase in this file, because
 			// it deletes pool
 			By("Create a PVC and Delete PVC when backend pool deleted", func() {

e2e/utils.go

@@ -992,3 +992,40 @@ func pvcDeleteWhenPoolNotFound(pvcPath string, cephfs bool, f *framework.Framewo
 	err = deletePVCAndValidatePV(f.ClientSet, pvc, deployTimeout)
 	return err
 }
+
+func checkMountOptions(pvcPath, appPath string, f *framework.Framework, mountFlags []string) error {
+	pvc, err := loadPVC(pvcPath)
+	if pvc == nil {
+		return err
+	}
+
+	pvc.Namespace = f.UniqueName
+
+	app, err := loadApp(appPath)
+	if err != nil {
+		return err
+	}
+	app.Labels = map[string]string{"app": "validate-mount-opt"}
+	app.Namespace = f.UniqueName
+
+	err = createPVCAndApp("", f, pvc, app)
+	if err != nil {
+		return err
+	}
+
+	opt := metav1.ListOptions{
+		LabelSelector: "app=validate-mount-opt",
+	}
+
+	cmd := fmt.Sprintf("mount |grep %s", app.Spec.Containers[0].VolumeMounts[0].MountPath)
+	data, stdErr := execCommandInPod(f, cmd, app.Namespace, &opt)
+	Expect(stdErr).Should(BeEmpty())
+	for _, f := range mountFlags {
+		if !strings.Contains(data, f) {
+			return fmt.Errorf("mount option %s not found in %s", f, data)
+		}
+	}
+
+	err = deletePVCAndApp("", f, pvc, app)
+	return err
+}

pkg/rbd/nodeserver.go

@@ -399,6 +399,7 @@ func (ns *NodeServer) mountVolumeToStagePath(ctx context.Context, req *csi.NodeS
 	}
 
 	opt := []string{"_netdev"}
+	opt = csicommon.ConstructMountOptions(opt, req.GetVolumeCapability())
 	isBlock := req.GetVolumeCapability().GetBlock() != nil
 
 	if isBlock {