volume: also check cookie for possible duplicates

weed/server/volume_grpc_client_to_master.go

@@ -120,7 +120,7 @@ func (vs *VolumeServer) doHeartbeat(ctx context.Context, masterNode, masterGrpcA
 				return "", err
 			}
 		case <-tickChan:
-			glog.V(1).Infof("volume server %s:%d heartbeat", vs.store.Ip, vs.store.Port)
+			glog.V(2).Infof("volume server %s:%d heartbeat", vs.store.Ip, vs.store.Port)
 			if err = stream.Send(vs.store.CollectHeartbeat()); err != nil {
 				glog.V(0).Infof("Volume Server Failed to talk with master %s: %v", masterNode, err)
 				return "", err

weed/storage/volume_read_write.go

@@ -29,7 +29,7 @@ func (v *Volume) isFileUnchanged(n *needle.Needle) bool {
 			glog.V(0).Infof("Failed to check updated file at offset %d size %d: %v", nv.Offset.ToAcutalOffset(), nv.Size, err)
 			return false
 		}
-		if oldNeedle.Checksum == n.Checksum && bytes.Equal(oldNeedle.Data, n.Data) {
+		if oldNeedle.Cookie == n.Cookie && oldNeedle.Checksum == n.Checksum && bytes.Equal(oldNeedle.Data, n.Data) {
 			n.DataSize = oldNeedle.DataSize
 			return true
 		}