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

(cherry picked from commit cba1f9e3896c0526fa748cd1bb13470d5fae584a)
HDFS-7242. Code improvement for FSN#checkUnreadableBySuperuser. (Contributed by Yi Liu)

(cherry picked from commit 1c3ff0b7c892b9d70737c375fb6f4a6fc6dd6d81)
HDFS-7252. small refinement to the use of isInAnEZ in FSNamesystem. (Yi Liu via vinayakumarb)

(cherry picked from commit 368743140dd076ecd5af309c1ed83c5ae2d59fc8)
YARN-2699. Fixed a bug in CommonNodeLabelsManager that caused tests to fail when using ephemeral ports on NodeIDs. Contributed by Wangda Tan.

(cherry picked from commit abae63caf9c53b404f2f2db7d482555484eaeaf8)
YARN-2588. Standby RM fails to transitionToActive if previous transitionToActive failed with ZK exception. Contributed by Rohith Sharmaks
(cherry picked from commit a6aa6e42cacdbfcc1c2b7c19e7239204fe9ff654)
MAPREDUCE-5542. Killing a job just as it finishes can generate an NPE in client. Contributed by Rohith
(cherry picked from commit 209b1699fcd150676d4cc47e8e817796086c1986)
HDFS-6924. Add new RAM_DISK storage type. (Arpit Agarwal)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/CHANGES-HDFS-6581.txt
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/StorageType.java
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelper.java
	hadoop-hdfs-project/hadoop-hdfs/src/main/proto/hdfs.proto
HDFS-6922. Add LazyPersist flag to INodeFile, save it in FsImage and edit logs. (Arpit Agarwal)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/CHANGES-HDFS-6581.txt
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogLoader.java
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSImageFormat.java
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSImageFormatPBINode.java
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSImageSerialization.java
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INodeFile.java
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INodeFileAttributes.java
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeLayoutVersion.java
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/snapshot/FSImageFormatPBSnapshot.java
	hadoop-hdfs-project/hadoop-hdfs/src/main/proto/fsimage.proto
	hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/CreateEditsLog.java
	hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestEditLog.java
	hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSPermissionChecker.java
	hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestINodeFile.java
HDFS-6923. Propagate LazyPersist flag to DNs via DataTransferProtocol. (Arpit Agarwal)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/CHANGES-HDFS-6581.txt
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSOutputStream.java
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/Receiver.java
HDFS-6925. DataNode should attempt to place replicas on transient storage first if lazyPersist flag is received. (Arpit Agarwal)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/CHANGES-HDFS-6581.txt
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/FsVolumeSpi.java
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsDatasetImpl.java
	hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDirectoryScanner.java
HDFS-6926. DN support for saving replicas to persistent storage and evicting in-memory replicas. (Arpit Agarwal)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/CHANGES-HDFS-6581.txt
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsDatasetImpl.java
HDFS-6927. Initial unit tests for Lazy Persist files. (Arpit Agarwal)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/CHANGES-HDFS-6581.txt
HDFS-6929. NN periodically unlinks lazy persist files with missing replicas from namespace. (Arpit Agarwal)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/CHANGES-HDFS-6581.txt
HDFS-6928. 'hdfs put' command should accept lazyPersist flag for testing. (Arpit Agarwal)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/CHANGES-HDFS-6581.txt
HDFS-6960. Bugfix in LazyWriter, fix test case and some refactoring. (Arpit Agarwal)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/CHANGES-HDFS-6581.txt
HDFS-6931. Move lazily persisted replicas to finalized directory on DN startup. (Arpit Agarwal)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/CHANGES-HDFS-6581.txt
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsDatasetImpl.java
HDFS-6950. Add Additional unit tests for HDFS-6581. (Contributed by Xiaoyu Yao)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/CHANGES-HDFS-6581.txt
	hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/DFSTestUtil.java
HDFS-6930. Improve replica eviction from RAM disk. (Arpit Agarwal)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/CHANGES-HDFS-6581.txt
HDFS-6977. Delete all copies when a block is deleted from the block space. (Arpit Agarwal)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/CHANGES-HDFS-6581.txt
HDFS-6991. Notify NN of evicted block before deleting it from RAM disk. (Arpit Agarwal)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/CHANGES-HDFS-6581.txt
	hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/MiniDFSCluster.java