HDFS-5425. Renaming underconstruction file with snapshots can make NN failure on restart. Contributed by Vinay and Jing Zhao.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1541261 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -529,6 +529,9 @@ Release 2.3.0 - UNRELEASED
 
     HDFS-5488. Clean up TestHftpURLTimeout. (Haohui Mai via jing9)
 
+    HDFS-5425. Renaming underconstruction file with snapshots can make NN failure on 
+    restart. (jing9 and Vinay)
+
 Release 2.2.1 - UNRELEASED
 
   INCOMPATIBLE CHANGES

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

@@ -30,7 +30,6 @@
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
-import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
 import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
@@ -84,7 +83,6 @@
 import org.apache.hadoop.hdfs.server.namenode.startupprogress.Step;
 import org.apache.hadoop.hdfs.util.ChunkedArrayList;
 import org.apache.hadoop.hdfs.util.Holder;
-import org.apache.jasper.tagplugins.jstl.core.Remove;
 
 import com.google.common.base.Joiner;
 

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

@@ -824,7 +824,12 @@ private void loadFilesUnderConstruction(DataInput in,
         final INodesInPath iip = fsDir.getLastINodeInPath(path);
         INodeFile oldnode = INodeFile.valueOf(iip.getINode(0), path);
         cons.setLocalName(oldnode.getLocalNameBytes());
-        cons.setParent(oldnode.getParent());
+        INodeReference parentRef = oldnode.getParentReference();
+        if (parentRef != null) {
+          cons.setParentReference(parentRef);
+        } else {
+          cons.setParent(oldnode.getParent());
+        }
 
         if (oldnode instanceof INodeFileWithSnapshot) {
           cons = new INodeFileUnderConstructionWithSnapshot(cons,

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

@@ -2562,7 +2562,7 @@ LocatedBlock getAdditionalBlock(String src, long fileId, String clientName,
       final INode[] inodes = analyzeFileState(
           src, fileId, clientName, previous, onRetryBlock).getINodes();
       final INodeFileUnderConstruction pendingFile =
-          (INodeFileUnderConstruction) inodes[inodes.length - 1];
+          (INodeFileUnderConstruction) inodes[inodes.length - 1].asFile();
 
       if (onRetryBlock[0] != null && onRetryBlock[0].getLocations().length > 0) {
         // This is a retry. Just return the last block if having locations.
@@ -2600,7 +2600,7 @@ LocatedBlock getAdditionalBlock(String src, long fileId, String clientName,
           analyzeFileState(src, fileId, clientName, previous, onRetryBlock);
       INode[] inodes = inodesInPath.getINodes();
       final INodeFileUnderConstruction pendingFile =
-          (INodeFileUnderConstruction) inodes[inodes.length - 1];
+          (INodeFileUnderConstruction) inodes[inodes.length - 1].asFile();
 
       if (onRetryBlock[0] != null) {
         if (onRetryBlock[0].getLocations().length > 0) {

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

@@ -595,7 +595,15 @@ public boolean removeChild(INode child, Snapshot latest,
   public void replaceChild(final INode oldChild, final INode newChild,
       final INodeMap inodeMap) {
     super.replaceChild(oldChild, newChild, inodeMap);
-    diffs.replaceChild(ListType.CREATED, oldChild, newChild);
+    if (oldChild.getParentReference() != null && !newChild.isReference()) {
+      // oldChild is referred by a Reference node. Thus we are replacing the 
+      // referred inode, e.g., 
+      // INodeFileWithSnapshot -> INodeFileUnderConstructionWithSnapshot
+      // in this case, we do not need to update the diff list
+      return;
+    } else {
+      diffs.replaceChild(ListType.CREATED, oldChild, newChild);
+    }
   }
   
   /**

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/snapshot/TestRenameWithSnapshots.java

@@ -29,6 +29,7 @@
 
 import java.io.File;
 import java.io.IOException;
+import java.util.EnumSet;
 import java.util.List;
 import java.util.Random;
 
@@ -40,9 +41,12 @@
 import org.apache.hadoop.fs.Options.Rename;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.permission.FsPermission;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.DFSOutputStream;
 import org.apache.hadoop.hdfs.DFSTestUtil;
 import org.apache.hadoop.hdfs.DistributedFileSystem;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.apache.hadoop.hdfs.client.HdfsDataOutputStream.SyncFlag;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants.SafeModeAction;
 import org.apache.hadoop.hdfs.protocol.QuotaExceededException;
@@ -102,6 +106,7 @@ public class TestRenameWithSnapshots {
   
   @Before
   public void setUp() throws Exception {
+    conf.setLong(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, BLOCKSIZE);
     cluster = new MiniDFSCluster.Builder(conf).numDataNodes(REPL).format(true)
         .build();
     cluster.waitActive();
@@ -2289,4 +2294,49 @@ public void testCleanDstReference() throws Exception {
     assertEquals(0, diff.getChildrenDiff().getList(ListType.DELETED).size());
     assertEquals(0, diff.getChildrenDiff().getList(ListType.CREATED).size());
   }
+
+  /**
+   * Rename of the underconstruction file in snapshot should not fail NN restart
+   * after checkpoint. Unit test for HDFS-5425.
+   */
+  @Test
+  public void testRenameUCFileInSnapshot() throws Exception {
+    final Path test = new Path("/test");
+    final Path foo = new Path(test, "foo");
+    final Path bar = new Path(foo, "bar");
+    hdfs.mkdirs(foo);
+    // create a file and keep it as underconstruction.
+    hdfs.create(bar);
+    SnapshotTestHelper.createSnapshot(hdfs, test, "s0");
+    // rename bar --> bar2
+    final Path bar2 = new Path(foo, "bar2");
+    hdfs.rename(bar, bar2);
+
+    // save namespace and restart
+    restartClusterAndCheckImage(true);
+  }
+  
+  /**
+   * Similar with testRenameUCFileInSnapshot, but do renaming first and then 
+   * append file without closing it. Unit test for HDFS-5425.
+   */
+  @Test
+  public void testAppendFileAfterRenameInSnapshot() throws Exception {
+    final Path test = new Path("/test");
+    final Path foo = new Path(test, "foo");
+    final Path bar = new Path(foo, "bar");
+    DFSTestUtil.createFile(hdfs, bar, BLOCKSIZE, REPL, SEED);
+    SnapshotTestHelper.createSnapshot(hdfs, test, "s0");
+    // rename bar --> bar2
+    final Path bar2 = new Path(foo, "bar2");
+    hdfs.rename(bar, bar2);
+    // append file and keep it as underconstruction.
+    FSDataOutputStream out = hdfs.append(bar2);
+    out.writeByte(0);
+    ((DFSOutputStream) out.getWrappedStream()).hsync(
+        EnumSet.of(SyncFlag.UPDATE_LENGTH));
+
+    // save namespace and restart
+    restartClusterAndCheckImage(true);
+  }
 }