HDFS-6135. Merge r1581071 from branch-2.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.4@1581072 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -413,6 +413,9 @@ Release 2.4.0 - UNRELEASED
     HDFS-6140. WebHDFS cannot create a file with spaces in the name after HA
     failover changes. (cnauroth)
 
+    HDFS-6135. In HDFS upgrade with HA setup, JournalNode cannot handle layout
+    version bump when rolling back. (jing9)
+
   BREAKDOWN OF HDFS-5698 SUBTASKS AND RELATED JIRAS
 
     HDFS-5717. Save FSImage header in protobuf. (Haohui Mai via jing9)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/qjournal/server/JNStorage.java

@@ -20,6 +20,7 @@ package org.apache.hadoop.hdfs.qjournal.server;
 import java.io.File;
 import java.io.IOException;
 import java.util.List;
+import java.util.Properties;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -27,6 +28,8 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileUtil;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.NodeType;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.StartupOption;
+import org.apache.hadoop.hdfs.server.common.InconsistentFSStateException;
+import org.apache.hadoop.hdfs.server.common.IncorrectVersionException;
 import org.apache.hadoop.hdfs.server.common.Storage;
 import org.apache.hadoop.hdfs.server.common.StorageErrorReporter;
 import org.apache.hadoop.hdfs.server.namenode.FileJournalManager;
@@ -203,6 +206,16 @@ class JNStorage extends Storage {
     }
   }
 
+  @Override
+  protected void setLayoutVersion(Properties props, StorageDirectory sd)
+      throws IncorrectVersionException, InconsistentFSStateException {
+    int lv = Integer.parseInt(getProperty(props, sd, "layoutVersion"));
+    // For journal node, since it now does not decode but just scan through the
+    // edits, it can handle edits with future version in most of the cases.
+    // Thus currently we may skip the layoutVersion check here.
+    layoutVersion = lv;
+  }
+
   void checkConsistentNamespace(NamespaceInfo nsInfo)
       throws IOException {
     if (nsInfo.getNamespaceID() != getNamespaceID()) {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/common/StorageInfo.java

@@ -202,7 +202,7 @@ public class StorageInfo {
         : NameNodeLayoutVersion.FEATURES;
   }
 
-  static String getProperty(Properties props, StorageDirectory sd,
+  protected static String getProperty(Properties props, StorageDirectory sd,
       String name) throws InconsistentFSStateException {
     String property = props.getProperty(name);
     if (property == null) {