HDFS-5306. Merging change r1529562 from trunk

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1529563 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10017. Merge change r1529571 from trunk.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1529572 13f79535-47bb-0310-9956-ffa450edef68