volume: change all writes to fsync during graceful stopping

fix https://github.com/chrislusf/seaweedfs/issues/2193

weed/command/volume.go

@@ -259,6 +259,7 @@ func (v VolumeServerOptions) startVolumeServer(volumeFolders, maxVolumeCounts, v
 
 		// Stop heartbeats
 		if !volumeServer.StopHeartbeat() {
+			volumeServer.SetStopping()
 			glog.V(0).Infof("stop send heartbeat and wait %d seconds until shutdown ...", *v.preStopSeconds)
 			time.Sleep(time.Duration(*v.preStopSeconds) * time.Second)
 		}

weed/server/volume_server.go

@@ -112,6 +112,11 @@ func NewVolumeServer(adminMux, publicMux *http.ServeMux, ip string,
 	return vs
 }
 
+func (vs *VolumeServer) SetStopping() {
+	glog.V(0).Infoln("Stopping volume server...")
+	vs.store.SetStopping()
+}
+
 func (vs *VolumeServer) Shutdown() {
 	glog.V(0).Infoln("Shutting down volume server...")
 	vs.store.Close()

weed/storage/store.go

@@ -46,6 +46,7 @@ type Store struct {
 	DeletedVolumesChan  chan master_pb.VolumeShortInformationMessage
 	NewEcShardsChan     chan master_pb.VolumeEcShardInformationMessage
 	DeletedEcShardsChan chan master_pb.VolumeEcShardInformationMessage
+	isStopping          bool
 }
 
 func (s *Store) String() (str string) {
@@ -321,6 +322,10 @@ func (s *Store) CollectHeartbeat() *master_pb.Heartbeat {
 
 }
 
+func (s *Store) SetStopping() {
+	s.isStopping = true
+}
+
 func (s *Store) Close() {
 	for _, location := range s.Locations {
 		location.Close()
@@ -333,7 +338,7 @@ func (s *Store) WriteVolumeNeedle(i needle.VolumeId, n *needle.Needle, fsync boo
 			err = fmt.Errorf("volume %d is read only", i)
 			return
 		}
-		_, _, isUnchanged, err = v.writeNeedle2(n, fsync)
+		_, _, isUnchanged, err = v.writeNeedle2(n, fsync && s.isStopping)
 		return
 	}
 	glog.V(0).Infoln("volume", i, "not found!")