master: better locking of in memory volume data

related to https://github.com/chrislusf/seaweedfs/issues/1436#issuecomment-695880135

weed/topology/data_node.go

@@ -44,6 +44,10 @@ func (dn *DataNode) String() string {
 func (dn *DataNode) AddOrUpdateVolume(v storage.VolumeInfo) (isNew, isChangedRO bool) {
 	dn.Lock()
 	defer dn.Unlock()
+	return dn.doAddOrUpdateVolume(v)
+}
+
+func (dn *DataNode) doAddOrUpdateVolume(v storage.VolumeInfo) (isNew, isChangedRO bool) {
 	if oldV, ok := dn.volumes[v.Id]; !ok {
 		dn.volumes[v.Id] = v
 		dn.UpAdjustVolumeCountDelta(1)
@@ -71,11 +75,15 @@ func (dn *DataNode) AddOrUpdateVolume(v storage.VolumeInfo) (isNew, isChangedRO
 }
 
 func (dn *DataNode) UpdateVolumes(actualVolumes []storage.VolumeInfo) (newVolumes, deletedVolumes, changeRO []storage.VolumeInfo) {
+
 	actualVolumeMap := make(map[needle.VolumeId]storage.VolumeInfo)
 	for _, v := range actualVolumes {
 		actualVolumeMap[v.Id] = v
 	}
+
 	dn.Lock()
+	defer dn.Unlock()
+
 	for vid, v := range dn.volumes {
 		if _, ok := actualVolumeMap[vid]; !ok {
 			glog.V(0).Infoln("Deleting volume id:", vid)
@@ -90,9 +98,8 @@ func (dn *DataNode) UpdateVolumes(actualVolumes []storage.VolumeInfo) (newVolume
 			}
 		}
 	}
-	dn.Unlock()
 	for _, v := range actualVolumes {
-		isNew, isChangedRO := dn.AddOrUpdateVolume(v)
+		isNew, isChangedRO := dn.doAddOrUpdateVolume(v)
 		if isNew {
 			newVolumes = append(newVolumes, v)
 		}
@@ -103,8 +110,10 @@ func (dn *DataNode) UpdateVolumes(actualVolumes []storage.VolumeInfo) (newVolume
 	return
 }
 
-func (dn *DataNode) DeltaUpdateVolumes(newlVolumes, deletedVolumes []storage.VolumeInfo) {
+func (dn *DataNode) DeltaUpdateVolumes(newVolumes, deletedVolumes []storage.VolumeInfo) {
 	dn.Lock()
+	defer dn.Unlock()
+
 	for _, v := range deletedVolumes {
 		delete(dn.volumes, v.Id)
 		dn.UpAdjustVolumeCountDelta(-1)
@@ -115,9 +124,8 @@ func (dn *DataNode) DeltaUpdateVolumes(newlVolumes, deletedVolumes []storage.Vol
 			dn.UpAdjustActiveVolumeCountDelta(-1)
 		}
 	}
-	dn.Unlock()
-	for _, v := range newlVolumes {
-		dn.AddOrUpdateVolume(v)
+	for _, v := range newVolumes {
+		dn.doAddOrUpdateVolume(v)
 	}
 	return
 }