Merge changes r1453645 for HADOOP-9373, r1453675 for HADOOP-9376, r1453676 for HADOOP-9365, r1454108 for HADOOP-9364.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1485853 13f79535-47bb-0310-9956-ffa450edef68