HDFS-7869. Inconsistency in the return information while performing rolling upgrade ( Contributed by J.Andreina )

(cherry picked from commit 3560180b6e)

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

@@ -777,6 +777,9 @@ Release 2.7.0 - UNRELEASED
     HDFS-7682. {{DistributedFileSystem#getFileChecksum}} of a snapshotted file
     includes non-snapshotted content. (Charles Lamb via atm)
 
+    HDFS-7869. Inconsistency in the return information while performing rolling
+    upgrade ( J.Andreina via vinayakumarb )
+
     BREAKDOWN OF HDFS-7584 SUBTASKS AND RELATED JIRAS
 
       HDFS-7720. Quota by Storage Type API, tools and ClientNameNode

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java

@@ -7475,7 +7475,7 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
     }
   }
 
-  void finalizeRollingUpgrade() throws IOException {
+  RollingUpgradeInfo finalizeRollingUpgrade() throws IOException {
     checkSuperuserPrivilege();
     checkOperation(OperationCategory.WRITE);
     writeLock();
@@ -7483,7 +7483,7 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
     try {
       checkOperation(OperationCategory.WRITE);
       if (!isRollingUpgrade()) {
-        return;
+        return null;
       }
       checkNameNodeSafeMode("Failed to finalize rolling upgrade");
 
@@ -7508,7 +7508,7 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
     if (auditLog.isInfoEnabled() && isExternalInvocation()) {
       logAuditEvent(true, "finalizeRollingUpgrade", null, null, null);
     }
-    return;
+    return returnInfo;
   }
 
   RollingUpgradeInfo finalizeRollingUpgradeInternal(long finalizeTime)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeRpcServer.java

@@ -1139,8 +1139,7 @@ class NameNodeRpcServer implements NamenodeProtocols {
     case PREPARE:
       return namesystem.startRollingUpgrade();
     case FINALIZE:
-      namesystem.finalizeRollingUpgrade();
+      return namesystem.finalizeRollingUpgrade();
-      return null;
     default:
       throw new UnsupportedActionException(action + " is not yet supported.");
     }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DFSAdmin.java

@@ -341,7 +341,7 @@ public class DFSAdmin extends FsShell {
     private static void printMessage(RollingUpgradeInfo info,
         PrintStream out) {
       if (info != null && info.isStarted()) {
-        if (!info.createdRollbackImages()) {
+        if (!info.createdRollbackImages() && !info.isFinalized()) {
           out.println(
               "Preparing for upgrade. Data is being saved for rollback."
               + "\nRun \"dfsadmin -rollingUpgrade query\" to check the status"

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestRollingUpgrade.java

@@ -244,7 +244,7 @@ public class TestRollingUpgrade {
       //finalize rolling upgrade
       final RollingUpgradeInfo finalize = dfs2.rollingUpgrade(
           RollingUpgradeAction.FINALIZE);
-      Assert.assertNull(finalize);
+      Assert.assertTrue(finalize.isFinalized());
 
       LOG.info("RESTART cluster 2 with regular startup option");
       cluster2.getNameNodeInfos()[0].setStartOpt(StartupOption.REGULAR);
@@ -405,7 +405,7 @@ public class TestRollingUpgrade {
       Assert.assertTrue(fsimage.hasRollbackFSImage());
 
       info = dfs.rollingUpgrade(RollingUpgradeAction.FINALIZE);
-      Assert.assertNull(info);
+      Assert.assertTrue(info.isFinalized());
       Assert.assertTrue(dfs.exists(foo));
 
       // Once finalized, there should be no more fsimage for rollbacks.