HDFS-6593. Merge r1605169 from trunk.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1605180 13f79535-47bb-0310-9956-ffa450edef68
HDFS-6587. Merge r1605184 from trunk.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1605186 13f79535-47bb-0310-9956-ffa450edef68