svn merge -c 1609543 merging from trunk to branch-2 to fix:HDFS-6647. Edit log corruption when pipeline recovery occurs for deleted file present in snapshot. Contributed by Kihwal Lee.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1609544 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -555,6 +555,9 @@ Release 2.5.0 - UNRELEASED
     HDFS-6631. TestPread#testHedgedReadLoopTooManyTimes fails intermittently.
     (Liang Xie via cnauroth)
 
+    HDFS-6647. Edit log corruption when pipeline recovery occurs for deleted 
+    file present in snapshot (kihwal)
+
   BREAKDOWN OF HDFS-2006 SUBTASKS AND RELATED JIRAS
 
     HDFS-6299. Protobuf for XAttr and client-side implementation. (Yi Liu via umamahesh)

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

@@ -3101,10 +3101,9 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
               : "Holder " + holder + " does not have any open files."));
     }
     // No further modification is allowed on a deleted file.
-    // A file is considered deleted, if it has no parent or is marked
+    // A file is considered deleted, if it is not in the inodeMap or is marked
     // as deleted in the snapshot feature.
-    if (file.getParent() == null || (file.isWithSnapshot() &&
+    if (isFileDeleted(file)) {
-        file.getFileWithSnapshotFeature().isCurrentFileDeleted())) {
       throw new FileNotFoundException(src);
     }
     String clientName = file.getFileUnderConstructionFeature().getClientName();
@@ -6251,6 +6250,16 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
     return blockId;
   }
 
+  private boolean isFileDeleted(INodeFile file) {
+    // Not in the inodeMap or in the snapshot but marked deleted.
+    if (dir.getInode(file.getId()) == null || 
+        file.getParent() == null || (file.isWithSnapshot() &&
+        file.getFileWithSnapshotFeature().isCurrentFileDeleted())) {
+      return true;
+    }
+    return false;
+  }
+
   private INodeFile checkUCBlock(ExtendedBlock block,
       String clientName) throws IOException {
     assert hasWriteLock();
@@ -6267,7 +6276,7 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
     
     // check file inode
     final INodeFile file = ((INode)storedBlock.getBlockCollection()).asFile();
-    if (file == null || !file.isUnderConstruction()) {
+    if (file == null || !file.isUnderConstruction() || isFileDeleted(file)) {
       throw new IOException("The file " + storedBlock + 
           " belonged to does not exist or it is not under construction.");
     }

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

@@ -0,0 +1,109 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hdfs.server.namenode.snapshot;
+
+import java.io.IOException;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hdfs.DFSOutputStream;
+import org.apache.hadoop.hdfs.DFSTestUtil;
+import org.apache.hadoop.hdfs.DistributedFileSystem;
+import org.apache.hadoop.hdfs.HdfsConfiguration;
+import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
+import org.apache.hadoop.hdfs.protocol.LocatedBlock;
+import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocols;
+import org.apache.hadoop.io.IOUtils;
+import static org.apache.hadoop.test.GenericTestUtils.assertExceptionContains;
+import org.junit.Test;
+
+public class TestUpdatePipelineWithSnapshots {
+  
+  // Regression test for HDFS-6647.
+  @Test
+  public void testUpdatePipelineAfterDelete() throws Exception {
+    Configuration conf = new HdfsConfiguration();
+    Path file = new Path("/test-file");    
+    MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
+    
+    try {
+      FileSystem fs = cluster.getFileSystem();
+      NamenodeProtocols namenode = cluster.getNameNodeRpc();
+      DFSOutputStream out = null;
+      try {
+        // Create a file and make sure a block is allocated for it.
+        out = (DFSOutputStream)(fs.create(file).
+            getWrappedStream()); 
+        out.write(1);
+        out.hflush();
+        
+        // Create a snapshot that includes the file.
+        SnapshotTestHelper.createSnapshot((DistributedFileSystem) fs,
+            new Path("/"), "s1");
+        
+        // Grab the block info of this file for later use.
+        FSDataInputStream in = null;
+        ExtendedBlock oldBlock = null;
+        try {
+          in = fs.open(file);
+          oldBlock = DFSTestUtil.getAllBlocks(in).get(0).getBlock();
+        } finally {
+          IOUtils.closeStream(in);
+        }
+        
+        // Allocate a new block ID/gen stamp so we can simulate pipeline
+        // recovery.
+        String clientName = ((DistributedFileSystem)fs).getClient()
+            .getClientName();
+        LocatedBlock newLocatedBlock = namenode.updateBlockForPipeline(
+            oldBlock, clientName);
+        ExtendedBlock newBlock = new ExtendedBlock(oldBlock.getBlockPoolId(),
+            oldBlock.getBlockId(), oldBlock.getNumBytes(), 
+            newLocatedBlock.getBlock().getGenerationStamp());
+
+        // Delete the file from the present FS. It will still exist the
+        // previously-created snapshot. This will log an OP_DELETE for the
+        // file in question.
+        fs.delete(file, true);
+        
+        // Simulate a pipeline recovery, wherein a new block is allocated
+        // for the existing block, resulting in an OP_UPDATE_BLOCKS being
+        // logged for the file in question.
+        try {
+          namenode.updatePipeline(clientName, oldBlock, newBlock,
+              newLocatedBlock.getLocations(), newLocatedBlock.getStorageIDs());
+        } catch (IOException ioe) {
+          // normal
+          assertExceptionContains(
+              "does not exist or it is not under construction", ioe);
+        }
+        
+        // Make sure the NN can restart with the edit logs as we have them now.
+        cluster.restartNameNode(true);
+      } finally {
+        IOUtils.closeStream(out);
+      }
+    } finally {
+      cluster.shutdown();
+    }
+  }
+
+}