rwx: remount and reexport volume if share manager is in running state

Longhorn 7106

Signed-off-by: Derek Su <derek.su@suse.com>
(cherry picked from commit 83d3435)

controller/share_manager_controller.go

@@ -432,6 +432,31 @@ func (c *ShareManagerController) unmountShareManagerVolume(sm *longhorn.ShareMan
 	}
 }
 
+// mountShareManagerVolume checks, exports and mounts the volume in the share manager pod.
+func (c *ShareManagerController) mountShareManagerVolume(sm *longhorn.ShareManager) error {
+	podName := types.GetShareManagerPodNameFromShareManagerName(sm.Name)
+	pod, err := c.ds.GetPod(podName)
+	if err != nil && !apierrors.IsNotFound(err) {
+		return errors.Wrapf(err, "failed to retrieve pod %v for share manager from datastore", podName)
+	}
+
+	if pod == nil {
+		return fmt.Errorf("pod %v for share manager not found", podName)
+	}
+
+	client, err := engineapi.NewShareManagerClient(sm, pod)
+	if err != nil {
+		return errors.Wrapf(err, "failed to create share manager client for pod %v", podName)
+	}
+	defer client.Close()
+
+	if err := client.Mount(); err != nil {
+		return errors.Wrapf(err, "failed to mount share manager pod %v", podName)
+	}
+
+	return nil
+}
+
 func hasActiveWorkload(vol *longhorn.Volume) bool {
 	if vol == nil {
 		return false
@@ -500,7 +525,7 @@ func (c *ShareManagerController) syncShareManagerVolume(sm *longhorn.ShareManage
 		}
 		return nil
 	} else if sm.Status.State == longhorn.ShareManagerStateRunning {
-		return nil
+		return c.mountShareManagerVolume(sm)
 	}
 
 	// in a single node cluster, there is no other manager that can claim ownership so we are prevented from creation

engineapi/share_manager.go

@@ -42,3 +42,7 @@ func (c *ShareManagerClient) FilesystemTrim(encryptedDevice bool) error {
 func (c *ShareManagerClient) Unmount() error {
 	return c.grpcClient.Unmount()
 }
+
+func (c *ShareManagerClient) Mount() error {
+	return c.grpcClient.Mount()
+}