HDFS-5065. Merging change r1512870 from trunk to branch-2.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1512871 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-9802. Merging change r1512872 from trunk to branch-2.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1512874 13f79535-47bb-0310-9956-ffa450edef68