HDFS-5234. Merging change r1525104 from trunk

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1525109 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5231. Merge change r1525133 from trunk.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1525134 13f79535-47bb-0310-9956-ffa450edef68