From a96ff860449ced505f481486d603b904f846bf42 Mon Sep 17 00:00:00 2001
From: Arpit Agarwal <arp@apache.org>
Date: Sat, 11 Jan 2014 00:14:19 +0000
Subject: [PATCH] HDFS-5747. Merging r1557289 from trunk to branch-2.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1557291 13f79535-47bb-0310-9956-ffa450edef68
---
 hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt               | 4 +++-
 .../blockmanagement/BlockInfoUnderConstruction.java       | 8 +++++---
 .../org/apache/hadoop/hdfs/server/namenode/NameNode.java  | 2 +-
 3 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index 06cb2d07b0a..74b0829d837 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -260,7 +260,9 @@ Release 2.4.0 - UNRELEASED
     HDFS-5756. hadoopRzOptionsSetByteBufferPool does not accept NULL argument,
     contrary to docs. (cmccabe via wang)
 
-BREAKDOWN OF HDFS-2832 SUBTASKS AND RELATED JIRAS
+    HDFS-5747. Fix NPEs in BlockManager. (Arpit Agarwal)
+
+  BREAKDOWN OF HDFS-2832 SUBTASKS AND RELATED JIRAS
 
     HDFS-4985. Add storage type to the protocol and expose it in block report
     and block locations. (Arpit Agarwal)
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockInfoUnderConstruction.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockInfoUnderConstruction.java
index 54e560ddeb8..1161077f49d 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockInfoUnderConstruction.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockInfoUnderConstruction.java
@@ -324,12 +324,14 @@ void addReplicaIfNotPresent(DatanodeStorageInfo storage,
     Iterator<ReplicaUnderConstruction> it = replicas.iterator();
     while (it.hasNext()) {
       ReplicaUnderConstruction r = it.next();
-      if(r.getExpectedStorageLocation() == storage) {
+      DatanodeStorageInfo expectedLocation = r.getExpectedStorageLocation();
+      if(expectedLocation == storage) {
         // Record the gen stamp from the report
         r.setGenerationStamp(block.getGenerationStamp());
         return;
-      } else if (r.getExpectedStorageLocation().getDatanodeDescriptor() ==
-          storage.getDatanodeDescriptor()) {
+      } else if (expectedLocation != null &&
+                 expectedLocation.getDatanodeDescriptor() ==
+                     storage.getDatanodeDescriptor()) {
 
         // The Datanode reported that the block is on a different storage
         // than the one chosen by BlockPlacementPolicy. This can occur as
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNode.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNode.java
index 2346a358d7e..163930789c0 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNode.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNode.java
@@ -549,8 +549,8 @@ private void startCommonServices(Configuration conf) throws IOException {
   }
   
   private void stopCommonServices() {
-    if(namesystem != null) namesystem.close();
     if(rpcServer != null) rpcServer.stop();
+    if(namesystem != null) namesystem.close();
     if (pauseMonitor != null) pauseMonitor.stop();
     if (plugins != null) {
       for (ServicePlugin p : plugins) {