Fix https://github.com/chrislusf/seaweedfs/issues/825

weed/topology/topology.go

@@ -88,11 +88,13 @@ func (t *Topology) Lookup(collection string, vid storage.VolumeId) []*DataNode {
 	return nil
 }
 
-func (t *Topology) NextVolumeId() storage.VolumeId {
+func (t *Topology) NextVolumeId() (storage.VolumeId, error) {
 	vid := t.GetMaxVolumeId()
 	next := vid.Next()
-	go t.RaftServer.Do(NewMaxVolumeIdCommand(next))
-	return next
+	if _, err := t.RaftServer.Do(NewMaxVolumeIdCommand(next)); err != nil {
+		return 0, err
+	}
+	return next, nil
 }
 
 func (t *Topology) HasWritableVolume(option *VolumeGrowOption) bool {

weed/topology/volume_growth.go

@@ -82,7 +82,10 @@ func (vg *VolumeGrowth) findAndGrow(grpcDialOption grpc.DialOption, topo *Topolo
 	if e != nil {
 		return 0, e
 	}
-	vid := topo.NextVolumeId()
+	vid, raftErr := topo.NextVolumeId()
+	if raftErr != nil {
+		return 0, raftErr
+	}
 	err := vg.grow(grpcDialOption, topo, vid, option, servers...)
 	return len(servers), err
 }