csi: add VolumeLocks to NodeGetVolumeStats for RBD and CephFS

Acquire a targetPath lock in NodeGetVolumeStats to prevent running
multiple NodeGetVolumeStats call on same target path at once. This may
happen when ceph cluster has problems. This also matches the semantics
of locking in other gRPC calls.

Assisted-by: Claude <noreply@anthropic.com>
Signed-off-by: Rakshith R <rar@redhat.com>
(cherry picked from commit 45d14a3)

Author: Rakshith-R

internal/cephfs/nodeserver.go

@@ -915,6 +915,11 @@ func (ns *NodeServer) NodeGetVolumeStats(
 		return nil, status.Error(codes.InvalidArgument, err.Error())
 	}
 
+	if acquired := ns.VolumeLocks.TryAcquire(targetPath); !acquired {
+		return nil, status.Errorf(codes.Aborted, util.TargetPathOperationAlreadyExistsFmt, targetPath)
+	}
+	defer ns.VolumeLocks.Release(targetPath)
+
 	// health check first, return without stats if unhealthy
 	healthy, msg := ns.healthChecker.IsHealthy(volumeID, targetPath)
 

internal/rbd/nodeserver.go

@@ -1507,6 +1507,11 @@ func (ns *NodeServer) NodeGetVolumeStats(
 		return nil, status.Error(codes.InvalidArgument, err.Error())
 	}
 
+	if acquired := ns.VolumeLocks.TryAcquire(targetPath); !acquired {
+		return nil, status.Errorf(codes.Aborted, util.TargetPathOperationAlreadyExistsFmt, targetPath)
+	}
+	defer ns.VolumeLocks.Release(targetPath)
+
 	stat, err := os.Stat(targetPath)
 	if err != nil {
 		if util.IsCorruptedMountError(err) {