Repair (*Broadcaster).run goroutine leak

When execute 'docker swarm init' and 'docker swarm leave -f' on a node
repeatedly, the (*Broadcaster).run goroutine leak.

Signed-off-by: yangchenliang <[email protected]>

drivers/overlay/ov_network.go

@@ -715,16 +715,15 @@ func (n *network) initSandbox(restore bool) error {
 func (n *network) watchMiss(nlSock *nl.NetlinkSocket) {
 	t := time.Now()
 	for {
-		n.Lock()
-		nlFd := nlSock.GetFd()
-		n.Unlock()
-		if nlFd == -1 {
-			// The netlink socket got closed, simply exit to not leak this goroutine
-			return
-		}
-
 		msgs, err := nlSock.Receive()
 		if err != nil {
+			n.Lock()
+			nlFd := nlSock.GetFd()
+			n.Unlock()
+			if nlFd == -1 {
+				// The netlink socket got closed, simply exit to not leak this goroutine
+				return
+			}
 			logrus.Errorf("Failed to receive from netlink: %v ", err)
 			continue
 		}

networkdb/networkdb.go

@@ -262,6 +262,7 @@ func (nDB *NetworkDB) Close() {
 		logrus.Errorf("Could not close DB %s: %v", nDB.config.NodeName, err)
 	}
 
+	//Avoid (*Broadcaster).run goroutine leak
 	nDB.broadcaster.Close()
 }