YARN-2270. Made TestFSDownload#testDownloadPublicWithStatCache be skipped when there’s no ancestor permissions. Contributed by Akira Ajisaka.
svn merge --ignore-ancestry -c 1612460 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1612461 13f79535-47bb-0310-9956-ffa450edef68
svn merge -c 1612493 from trunk for HDFS-6702. Change DFSClient to pass the StorageType from the namenode to datanodes and change datanode to write block replicas using the specified storage type.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1612494 13f79535-47bb-0310-9956-ffa450edef68