move ipam.subnet.mutex to caller (#2571)

Author: hongzhen-ma

pkg/ipam/ipam.go

@@ -215,6 +215,7 @@ func (ipam *IPAM) GetPodAddress(podName string) []*SubnetAddress {
 	defer ipam.mutex.RUnlock()
 	addresses := []*SubnetAddress{}
 	for _, subnet := range ipam.Subnets {
+		subnet.mutex.RLock()
 		for _, nicName := range subnet.PodToNicList[podName] {
 			v4IP, v6IP, mac, protocol := subnet.GetPodAddress(podName, nicName)
 			switch protocol {
@@ -227,6 +228,7 @@ func (ipam *IPAM) GetPodAddress(podName string) []*SubnetAddress {
 				addresses = append(addresses, &SubnetAddress{Subnet: subnet, Ip: string(v6IP), Mac: mac})
 			}
 		}
+		subnet.mutex.RUnlock()
 	}
 	return addresses
 }

pkg/ipam/subnet.go

@@ -543,10 +543,8 @@ func (subnet *Subnet) joinFreeWithReserve() {
 	}
 }
 
+// This func is only called in ipam.GetPodAddress, move mutex to caller
 func (subnet *Subnet) GetPodAddress(podName, nicName string) (IP, IP, string, string) {
-	subnet.mutex.RLock()
-	defer subnet.mutex.RUnlock()
-
 	if subnet.Protocol == kubeovnv1.ProtocolIPv4 {
 		ip, mac := subnet.V4NicToIP[nicName], subnet.NicToMac[nicName]
 		return ip, "", mac, kubeovnv1.ProtocolIPv4