YARN-6420. RM startup failure due to wrong order in nodelabel editlog (Bibin A Chundatt via Varun Saxena)

(cherry picked from commit 19b89c4c7be0236aafded560b7bcad7e39d1c4ed)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/nodelabels/RMNodeLabelsManager.java

@@ -34,6 +34,7 @@ import java.util.concurrent.ConcurrentMap;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.yarn.api.records.NodeId;
+import org.apache.hadoop.yarn.api.records.NodeLabel;
 import org.apache.hadoop.yarn.api.records.Resource;
 import org.apache.hadoop.yarn.nodelabels.CommonNodeLabelsManager;
 import org.apache.hadoop.yarn.nodelabels.RMNodeLabel;
@@ -133,6 +134,17 @@ public class RMNodeLabelsManager extends CommonNodeLabelsManager {
     }
   }
 
+  @Override
+  public void addToCluserNodeLabels(Collection<NodeLabel> labels)
+      throws IOException {
+    try {
+      writeLock.lock();
+      super.addToCluserNodeLabels(labels);
+    } finally {
+      writeLock.unlock();
+    }
+  }
+
   @Override
   public void
       removeLabelsFromNode(Map<NodeId, Set<String>> removeLabelsFromNode)