Fix issues found in gometalinter

Signed-off-by: Madhu Rajanna <mrajanna@redhat.com>

pkg/rbd/controllerserver.go

@@ -55,16 +55,19 @@ var (
 // info from metadata store
 func (cs *ControllerServer) LoadExDataFromMetadataStore() error {
 	vol := &rbdVolume{}
+	// nolint: errcheck
 	cs.MetadataStore.ForAll("csi-rbd-vol-", vol, func(identifier string) error {
 		rbdVolumes[identifier] = vol
 		return nil
 	})
 
 	snap := &rbdSnapshot{}
+	// nolint: errcheck
 	cs.MetadataStore.ForAll("csi-rbd-(.*)-snap-", snap, func(identifier string) error {
 		rbdSnapshots[identifier] = snap
 		return nil
 	})
+
 	glog.Infof("Loaded %d volumes and %d snapshots from metadata store", len(rbdVolumes), len(rbdSnapshots))
 	return nil
 }
@@ -91,7 +94,11 @@ func (cs *ControllerServer) CreateVolume(ctx context.Context, req *csi.CreateVol
 		return nil, err
 	}
 	volumeNameMutex.LockKey(req.GetName())
-	defer volumeNameMutex.UnlockKey(req.GetName())
+	defer func() {
+		if err := volumeNameMutex.UnlockKey(req.GetName()); err != nil {
+			glog.Warningf("failed to unlock mutex volume:%s %v", req.GetName(), err)
+		}
+	}()
 
 	// Need to check for already existing volume name, and if found
 	// check for the requested capacity and already allocated capacity
@@ -208,7 +215,13 @@ func (cs *ControllerServer) DeleteVolume(ctx context.Context, req *csi.DeleteVol
 	// For now the image get unconditionally deleted, but here retention policy can be checked
 	volumeID := req.GetVolumeId()
 	volumeIDMutex.LockKey(volumeID)
-	defer volumeIDMutex.UnlockKey(volumeID)
+
+	defer func() {
+		if err := volumeIDMutex.UnlockKey(volumeID); err != nil {
+			glog.Warningf("failed to unlock mutex volume:%s %v", volumeID, err)
+		}
+	}()
+
 	rbdVol := &rbdVolume{}
 	if err := cs.MetadataStore.Get(volumeID, rbdVol); err != nil {
 		if os.IsNotExist(errors.Cause(err)) {
@@ -276,7 +289,12 @@ func (cs *ControllerServer) CreateSnapshot(ctx context.Context, req *csi.CreateS
 	}
 
 	snapshotNameMutex.LockKey(req.GetName())
-	defer snapshotNameMutex.UnlockKey(req.GetName())
+
+	defer func() {
+		if err := snapshotNameMutex.UnlockKey(req.GetName()); err != nil {
+			glog.Warningf("failed to unlock mutex snapshot:%s %v", req.GetName(), err)
+		}
+	}()
 
 	// Need to check for already existing snapshot name, and if found
 	// check for the requested source volume id and already allocated source volume id
@@ -397,7 +415,12 @@ func (cs *ControllerServer) DeleteSnapshot(ctx context.Context, req *csi.DeleteS
 		return nil, status.Error(codes.InvalidArgument, "Snapshot ID cannot be empty")
 	}
 	snapshotIDMutex.LockKey(snapshotID)
-	defer snapshotIDMutex.UnlockKey(snapshotID)
+
+	defer func() {
+		if err := snapshotIDMutex.UnlockKey(snapshotID); err != nil {
+			glog.Warningf("failed to unlock mutex snapshot:%s %v", snapshotID, err)
+		}
+	}()
 
 	rbdSnap := &rbdSnapshot{}
 	if err := cs.MetadataStore.Get(snapshotID, rbdSnap); err != nil {

pkg/rbd/nodeserver.go

@@ -60,7 +60,12 @@ func (ns *NodeServer) NodeUnstageVolume(ctx context.Context, req *csi.NodeUnstag
 func (ns *NodeServer) NodePublishVolume(ctx context.Context, req *csi.NodePublishVolumeRequest) (*csi.NodePublishVolumeResponse, error) {
 	targetPath := req.GetTargetPath()
 	targetPathMutex.LockKey(targetPath)
-	defer targetPathMutex.UnlockKey(targetPath)
+
+	defer func() {
+		if err := targetPathMutex.UnlockKey(targetPath); err != nil {
+			glog.Warningf("failed to unlock mutex targetpath:%s %v", targetPath, err)
+		}
+	}()
 
 	var volName string
 	isBlock := req.GetVolumeCapability().GetBlock() != nil
@@ -84,12 +89,12 @@ func (ns *NodeServer) NodePublishVolume(ctx context.Context, req *csi.NodePublis
 		if os.IsNotExist(err) {
 			if isBlock {
 				// create an empty file
-				targetPathFile, err := os.OpenFile(targetPath, os.O_CREATE|os.O_RDWR, 0750)
-				if err != nil {
+				targetPathFile, e := os.OpenFile(targetPath, os.O_CREATE|os.O_RDWR, 0750)
+				if e != nil {
 					glog.V(4).Infof("Failed to create targetPath:%s with error: %v", targetPath, err)
-					return nil, status.Error(codes.Internal, err.Error())
+					return nil, status.Error(codes.Internal, e.Error())
 				}
-				if err := targetPathFile.Close(); err != nil {
+				if err = targetPathFile.Close(); err != nil {
 					glog.V(4).Infof("Failed to close targetPath:%s with error: %v", targetPath, err)
 					return nil, status.Error(codes.Internal, err.Error())
 				}
@@ -153,7 +158,12 @@ func (ns *NodeServer) NodePublishVolume(ctx context.Context, req *csi.NodePublis
 func (ns *NodeServer) NodeUnpublishVolume(ctx context.Context, req *csi.NodeUnpublishVolumeRequest) (*csi.NodeUnpublishVolumeResponse, error) {
 	targetPath := req.GetTargetPath()
 	targetPathMutex.LockKey(targetPath)
-	defer targetPathMutex.UnlockKey(targetPath)
+
+	defer func() {
+		if err := targetPathMutex.UnlockKey(targetPath); err != nil {
+			glog.Warningf("failed to unlock mutex targetpath:%s %v", targetPath, err)
+		}
+	}()
 
 	notMnt, err := ns.mounter.IsNotMountPoint(targetPath)
 	if err != nil {
@@ -177,7 +187,6 @@ func (ns *NodeServer) NodeUnpublishVolume(ctx context.Context, req *csi.NodeUnpu
 
 	// Bind mounted device needs to be resolved by using resolveBindMountedBlockDevice
 	if devicePath == "devtmpfs" {
-		var err error
 		devicePath, err = resolveBindMountedBlockDevice(targetPath)
 		if err != nil {
 			return nil, status.Error(codes.Internal, err.Error())
@@ -206,13 +215,13 @@ func (ns *NodeServer) NodeUnpublishVolume(ctx context.Context, req *csi.NodeUnpu
 	}
 
 	// Unmapping rbd device
-	if err := detachRBDDevice(devicePath); err != nil {
+	if err = detachRBDDevice(devicePath); err != nil {
 		glog.V(3).Infof("failed to unmap rbd device: %s with error: %v", devicePath, err)
 		return nil, err
 	}
 
 	// Remove targetPath
-	if err := os.RemoveAll(targetPath); err != nil {
+	if err = os.RemoveAll(targetPath); err != nil {
 		glog.V(3).Infof("failed to remove targetPath: %s with error: %v", targetPath, err)
 		return nil, err
 	}
@@ -240,7 +249,7 @@ func parseFindMntResolveSource(out string) (string, error) {
 		return match[1], nil
 	}
 	// Check if out is a block device
-	reBlk := regexp.MustCompile("^devtmpfs\\[(/[^/]+(?:/[^/]*)*)\\]$")
+	reBlk := regexp.MustCompile(`^devtmpfs\\[(/[^/]+(?:/[^/]*)*)\\]$`)
 	if match := reBlk.FindStringSubmatch(out); match != nil {
 		return fmt.Sprintf("/dev%s", match[1]), nil
 	}

pkg/rbd/rbd.go

@@ -112,7 +112,10 @@ func (r *Driver) Run(driverName, nodeID, endpoint string, containerized bool, ca
 	}
 
 	r.cs = NewControllerServer(r.cd, cachePersister)
-	r.cs.LoadExDataFromMetadataStore()
+
+	if err = r.cs.LoadExDataFromMetadataStore(); err != nil {
+		glog.Fatalf("failed to load metadata from store, err %v\n", err)
+	}
 
 	s := csicommon.NewNonBlockingGRPCServer()
 	s.Start(endpoint, r.ids, r.cs, r.ns)

pkg/rbd/rbd_attach.go

@@ -229,7 +229,12 @@ func attachRBDImage(volOptions *rbdVolume, userID string, credentials map[string
 	devicePath, found := waitForPath(volOptions.Pool, image, 1, useNBD)
 	if !found {
 		attachdetachMutex.LockKey(imagePath)
-		defer attachdetachMutex.UnlockKey(imagePath)
+
+		defer func() {
+			if err = attachdetachMutex.UnlockKey(imagePath); err != nil {
+				glog.Warningf("failed to unlock mutex imagepath:%s %v", imagePath, err)
+			}
+		}()
 
 		_, err = execCommand("modprobe", []string{moduleName})
 		if err != nil {