increase counter only if not early terminated

weed/server/master_grpc_server.go

@@ -50,7 +50,6 @@ func (ms *MasterServer) SendHeartbeat(stream master_pb.Seaweed_SendHeartbeatServ
 				}
 				ms.clientChansLock.RUnlock()
 			}
-
 		}
 	}()
 
@@ -72,14 +71,14 @@ func (ms *MasterServer) SendHeartbeat(stream master_pb.Seaweed_SendHeartbeatServ
 			dc := ms.Topo.GetOrCreateDataCenter(dcName)
 			rack := dc.GetOrCreateRack(rackName)
 			dn = rack.GetOrCreateDataNode(heartbeat.Ip, int(heartbeat.Port), heartbeat.PublicUrl, heartbeat.MaxVolumeCounts)
-			dn.Counter++
-			glog.V(0).Infof("added volume server %v:%d", heartbeat.GetIp(), heartbeat.GetPort())
+			glog.V(0).Infof("added %d volume server %v:%d", dn.Counter, heartbeat.GetIp(), heartbeat.GetPort())
 			if err := stream.Send(&master_pb.HeartbeatResponse{
 				VolumeSizeLimit: uint64(ms.option.VolumeSizeLimitMB) * 1024 * 1024,
 			}); err != nil {
 				glog.Warningf("SendHeartbeat.Send volume size to %s:%d %v", dn.Ip, dn.Port, err)
 				return err
 			}
+			dn.Counter++
 		}
 
 		dn.AdjustMaxVolumeCounts(heartbeat.MaxVolumeCounts)