refactor(CSI-250): do not maintain redundant active mounts from node …

…server after publishing volume

pkg/wekafs/nodeserver.go

@@ -251,9 +251,11 @@ func (ns *NodeServer) NodePublishVolume(ctx context.Context, req *csi.NodePublis
 
 	err, unmount := volume.MountUnderlyingFS(ctx)
 	if err != nil {
-		unmount()
+		logger.Error().Err(err).Msg("Failed to mount underlying filesystem")
 		return NodePublishVolumeError(ctx, codes.Internal, "Failed to mount a parent filesystem, check Authentication: "+err.Error())
 	}
+	defer unmount() // unmount the parent mount since there is a bind mount anyway
+
 	fullPath := volume.GetFullPath(ctx)
 
 	targetPathDir := filepath.Dir(targetPath)
@@ -294,10 +296,8 @@ func (ns *NodeServer) NodePublishVolume(ctx context.Context, req *csi.NodePublis
 
 	// if we run in K8s isolated environment, 2nd mount must be done using mapped volume path
 	if err := mounter.Mount(fullPath, targetPath, "", innerMountOpts); err != nil {
-		var errList strings.Builder
-		errList.WriteString(err.Error())
-		unmount() // unmount only if mount bind failed
-		return NodePublishVolumeError(ctx, codes.Internal, fmt.Sprintf("failed to Mount device: %s at %s: %s", fullPath, targetPath, errList.String()))
+		logger.Error().Err(err).Str("full_path", fullPath).Str("target_path", targetPath).Msg("Failed to perform mount")
+		return NodePublishVolumeError(ctx, codes.Internal, fmt.Sprintf("failed to Mount device: %s at %s: %s", fullPath, targetPath, err.Error()))
 	}
 	result = "SUCCESS"
 	// Not doing unmount, NodePublish should do unmount but only when it unmounts bind successfully