From 5409908026dd791cce62a7d71ae56c92a70a9753 Mon Sep 17 00:00:00 2001
From: Jing Zhao <jing9@apache.org>
Date: Fri, 28 Feb 2014 01:23:52 +0000
Subject: [PATCH] HDFS-6032. -rollingUpgrade query hits NPE after the NN
 restarts. Contributed by Haohui Mai.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-5535@1572801 13f79535-47bb-0310-9956-ffa450edef68
---
 .../hadoop-hdfs/CHANGES_HDFS-5535.txt         |  3 +++
 .../hadoop/hdfs/server/namenode/FSImage.java  |  5 +++-
 .../hadoop/hdfs/TestRollingUpgrade.java       | 26 +++++++++++++++++++
 3 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES_HDFS-5535.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES_HDFS-5535.txt
index 0121ec9b9b..002afcd44b 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES_HDFS-5535.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES_HDFS-5535.txt
@@ -120,3 +120,6 @@ HDFS-5535 subtasks:
 
     HDFS-6029. Secondary NN fails to checkpoint after -rollingUpgrade prepare.
     (jing9)
+
+    HDFS-6032. -rollingUpgrade query hits NPE after the NN restarts. (Haohui Mai
+    via jing9)
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSImage.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSImage.java
index 3464b65037..e79b6c9224 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSImage.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSImage.java
@@ -881,9 +881,12 @@ private void loadFSImage(File imageFile, FSNamesystem target,
    */
   private void loadFSImage(File curFile, MD5Hash expectedMd5,
       FSNamesystem target, MetaRecoveryContext recovery) throws IOException {
+    // BlockPoolId is required when the FsImageLoader loads the rolling upgrade
+    // information. Make sure the ID is properly set.
+    target.setBlockPoolId(this.getBlockPoolID());
+
     FSImageFormat.LoaderDelegator loader = FSImageFormat.newLoader(conf, target);
     loader.load(curFile);
-    target.setBlockPoolId(this.getBlockPoolID());
 
     // Check that the image digest we loaded matches up with what
     // we expected
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestRollingUpgrade.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestRollingUpgrade.java
index f5003795a0..321f8843d0 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestRollingUpgrade.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestRollingUpgrade.java
@@ -432,6 +432,32 @@ public void testQuery() throws Exception {
     }
   }
 
+  @Test (timeout = 300000)
+  public void testQueryAfterRestart() throws IOException, InterruptedException {
+    final Configuration conf = new Configuration();
+    MiniDFSCluster cluster = null;
+    try {
+      cluster = new MiniDFSCluster.Builder(conf).numDataNodes(0).build();
+      cluster.waitActive();
+      DistributedFileSystem dfs = cluster.getFileSystem();
+
+      dfs.setSafeMode(SafeModeAction.SAFEMODE_ENTER);
+      // start rolling upgrade
+      dfs.rollingUpgrade(RollingUpgradeAction.PREPARE);
+      queryForPreparation(dfs);
+      dfs.setSafeMode(SafeModeAction.SAFEMODE_ENTER);
+      dfs.saveNamespace();
+      dfs.setSafeMode(SafeModeAction.SAFEMODE_LEAVE);
+
+      cluster.restartNameNodes();
+      dfs.rollingUpgrade(RollingUpgradeAction.QUERY);
+    } finally {
+      if (cluster != null) {
+        cluster.shutdown();
+      }
+    }
+  }
+
   @Test(timeout = 300000)
   public void testCheckpoint() throws IOException, InterruptedException {
     final Configuration conf = new Configuration();