HDFS-5728. Block recovery will fail if the metafile does not have crc for all chunks of the block. Contributed by Vinay.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1561223 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -594,6 +594,9 @@ Release 2.4.0 - UNRELEASED
     HDFS-5806. balancer should set SoTimeout to avoid indefinite hangs.
     (Nathan Roberts via Andrew Wang).
 
+    HDFS-5728. Block recovery will fail if the metafile does not have crc 
+    for all chunks of the block (Vinay via kihwal)
+
   BREAKDOWN OF HDFS-2832 SUBTASKS AND RELATED JIRAS
 
     HDFS-4985. Add storage type to the protocol and expose it in block report

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/BlockPoolSlice.java

@@ -23,6 +23,7 @@ import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.RandomAccessFile;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.DU;
@@ -191,7 +192,7 @@ class BlockPoolSlice {
             blockFile.length(), genStamp, volume, blockFile.getParentFile());
       } else {
         newReplica = new ReplicaWaitingToBeRecovered(blockId,
-            validateIntegrity(blockFile, genStamp), 
+            validateIntegrityAndSetLength(blockFile, genStamp), 
             genStamp, volume, blockFile.getParentFile());
       }
 
@@ -214,7 +215,7 @@ class BlockPoolSlice {
    * @param genStamp generation stamp of the block
    * @return the number of valid bytes
    */
-  private long validateIntegrity(File blockFile, long genStamp) {
+  private long validateIntegrityAndSetLength(File blockFile, long genStamp) {
     DataInputStream checksumIn = null;
     InputStream blockIn = null;
     try {
@@ -257,11 +258,25 @@ class BlockPoolSlice {
       IOUtils.readFully(blockIn, buf, 0, lastChunkSize);
 
       checksum.update(buf, 0, lastChunkSize);
+      long validFileLength;
       if (checksum.compare(buf, lastChunkSize)) { // last chunk matches crc
-        return lastChunkStartPos + lastChunkSize;
+        validFileLength = lastChunkStartPos + lastChunkSize;
       } else { // last chunck is corrupt
-        return lastChunkStartPos;
+        validFileLength = lastChunkStartPos;
       }
+
+      // truncate if extra bytes are present without CRC
+      if (blockFile.length() > validFileLength) {
+        RandomAccessFile blockRAF = new RandomAccessFile(blockFile, "rw");
+        try {
+          // truncate blockFile
+          blockRAF.setLength(validFileLength);
+        } finally {
+          blockRAF.close();
+        }
+      }
+
+      return validFileLength;
     } catch (IOException e) {
       FsDatasetImpl.LOG.warn(e);
       return 0;

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

@@ -19,20 +19,28 @@ package org.apache.hadoop.hdfs;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 
+import java.io.File;
 import java.io.IOException;
+import java.io.RandomAccessFile;
 
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hdfs.MiniDFSCluster.DataNodeProperties;
 import org.apache.hadoop.hdfs.protocol.Block;
+import org.apache.hadoop.hdfs.protocol.BlockLocalPathInfo;
 import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
 import org.apache.hadoop.hdfs.protocol.LocatedBlock;
+import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
 import org.apache.hadoop.hdfs.server.datanode.DataNode;
 import org.apache.hadoop.hdfs.server.datanode.DataNodeTestUtils;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.TestInterDatanodeProtocol;
 import org.apache.hadoop.hdfs.server.namenode.LeaseManager;
 import org.apache.hadoop.hdfs.server.namenode.NameNodeAdapter;
+import org.apache.hadoop.security.UserGroupInformation;
 import org.junit.Test;
 
 public class TestLeaseRecovery {
@@ -148,4 +156,55 @@ public class TestLeaseRecovery {
       if (cluster != null) {cluster.shutdown();}
     }
   }
+
+  /**
+   * Block Recovery when the meta file not having crcs for all chunks in block
+   * file
+   */
+  @Test
+  public void testBlockRecoveryWithLessMetafile() throws Exception {
+    Configuration conf = new Configuration();
+    conf.set(DFSConfigKeys.DFS_BLOCK_LOCAL_PATH_ACCESS_USER_KEY,
+        UserGroupInformation.getCurrentUser().getShortUserName());
+    MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).numDataNodes(1)
+        .build();
+    Path file = new Path("/testRecoveryFile");
+    DistributedFileSystem dfs = cluster.getFileSystem();
+    FSDataOutputStream out = dfs.create(file);
+    int count = 0;
+    while (count < 2 * 1024 * 1024) {
+      out.writeBytes("Data");
+      count += 4;
+    }
+    out.hsync();
+    // abort the original stream
+    ((DFSOutputStream) out.getWrappedStream()).abort();
+
+    LocatedBlocks locations = cluster.getNameNodeRpc().getBlockLocations(
+        file.toString(), 0, count);
+    ExtendedBlock block = locations.get(0).getBlock();
+    DataNode dn = cluster.getDataNodes().get(0);
+    BlockLocalPathInfo localPathInfo = dn.getBlockLocalPathInfo(block, null);
+    File metafile = new File(localPathInfo.getMetaPath());
+    assertTrue(metafile.exists());
+
+    // reduce the block meta file size
+    RandomAccessFile raf = new RandomAccessFile(metafile, "rw");
+    raf.setLength(metafile.length() - 20);
+    raf.close();
+
+    // restart DN to make replica to RWR
+    DataNodeProperties dnProp = cluster.stopDataNode(0);
+    cluster.restartDataNode(dnProp, true);
+
+    // try to recover the lease
+    DistributedFileSystem newdfs = (DistributedFileSystem) FileSystem
+        .newInstance(cluster.getConfiguration(0));
+    count = 0;
+    while (++count < 10 && !newdfs.recoverLease(file)) {
+      Thread.sleep(1000);
+    }
+    assertTrue("File should be closed", newdfs.recoverLease(file));
+
+  }
 }