HDFS-6995. Block should be placed in the client's 'rack-local' node if 'client-local' node is not available (vinayakumarb)
Adding missed test file
HDFS-7242. Code improvement for FSN#checkUnreadableBySuperuser. (Contributed by Yi Liu)
HDFS-7252. small refinement to the use of isInAnEZ in FSNamesystem. (Yi Liu via vinayakumarb)