Merge r1575381 from trunk.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1575382 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5986. Merging change r1575384 from trunk to branch-2.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1575385 13f79535-47bb-0310-9956-ffa450edef68