(cherry picked from commit f491f717e9ee6b75ad5cfca48da9c6297e94a8f7) Conflicts: hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/LeaseManager.java (cherry picked from commit 60d82ac61f2afa2a61c8eeabf20e45b5a89311d0)