From 576c113c594ed82331f5ca7c03dc17aeef96c8c8 Mon Sep 17 00:00:00 2001
From: chrislu <chris.lu@gmail.com>
Date: Sat, 10 Sep 2022 11:22:16 -0700
Subject: [PATCH] replace PR https://github.com/seaweedfs/seaweedfs/pull/3621

replace https://github.com/seaweedfs/seaweedfs/pull/3621
---
 weed/topology/data_center.go | 4 +++-
 weed/topology/rack.go        | 4 +++-
 weed/topology/topology.go    | 4 +++-
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/weed/topology/data_center.go b/weed/topology/data_center.go
index 35f63b11f..5ffbe4bb8 100644
--- a/weed/topology/data_center.go
+++ b/weed/topology/data_center.go
@@ -20,7 +20,9 @@ func NewDataCenter(id string) *DataCenter {
 }
 
 func (dc *DataCenter) GetOrCreateRack(rackName string) *Rack {
-	for _, c := range dc.Children() {
+	dc.Lock()
+	defer dc.Unlock()
+	for _, c := range dc.children {
 		rack := c.(*Rack)
 		if string(rack.Id()) == rackName {
 			return rack
diff --git a/weed/topology/rack.go b/weed/topology/rack.go
index 97e0a400e..d388e9c61 100644
--- a/weed/topology/rack.go
+++ b/weed/topology/rack.go
@@ -32,7 +32,9 @@ func (r *Rack) FindDataNode(ip string, port int) *DataNode {
 	return nil
 }
 func (r *Rack) GetOrCreateDataNode(ip string, port int, grpcPort int, publicUrl string, maxVolumeCounts map[string]uint32) *DataNode {
-	for _, c := range r.Children() {
+	r.Lock()
+	defer r.Unlock()
+	for _, c := range r.children {
 		dn := c.(*DataNode)
 		if dn.MatchLocation(ip, port) {
 			dn.LastSeen = time.Now().Unix()
diff --git a/weed/topology/topology.go b/weed/topology/topology.go
index 35224d280..406ee30f6 100644
--- a/weed/topology/topology.go
+++ b/weed/topology/topology.go
@@ -258,7 +258,9 @@ func (t *Topology) UnRegisterVolumeLayout(v storage.VolumeInfo, dn *DataNode) {
 }
 
 func (t *Topology) GetOrCreateDataCenter(dcName string) *DataCenter {
-	for _, c := range t.Children() {
+	t.Lock()
+	defer t.Unlock()
+	for _, c := range t.children {
 		dc := c.(*DataCenter)
 		if string(dc.Id()) == dcName {
 			return dc