HDFS-9188. Make block corruption related tests FsDataset-agnostic. (lei)

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

@@ -1529,6 +1529,8 @@ Release 2.8.0 - UNRELEASED
 
     HDFS-9223. Code cleanup for DatanodeDescriptor and HeartbeatManager. (jing9)
 
+    HDFS-9188. Make block corruption related tests FsDataset-agnostic. (lei)
+
   OPTIMIZATIONS
 
     HDFS-8026. Trace FSOutputSummer#writeChecksumChunks rather than

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

@@ -51,16 +51,13 @@ import java.io.File;
 import java.io.FileWriter;
 import java.io.IOException;
 import java.io.PrintWriter;
-import java.io.RandomAccessFile;
 import java.net.InetSocketAddress;
 import java.net.URI;
 import java.net.URISyntaxException;
-import java.nio.channels.FileChannel;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
-import java.util.Random;
 import java.util.Set;
 import java.util.concurrent.TimeoutException;
 
@@ -97,6 +94,9 @@ import org.apache.hadoop.hdfs.server.datanode.DataNode;
 import org.apache.hadoop.hdfs.server.datanode.DataNodeTestUtils;
 import org.apache.hadoop.hdfs.server.datanode.DataStorage;
 import org.apache.hadoop.hdfs.server.datanode.DatanodeUtil;
+import org.apache.hadoop.hdfs.server.datanode.FsDatasetTestUtils;
+import org.apache.hadoop.hdfs.server.datanode.FsDatasetTestUtils.MaterializedReplica;
+import org.apache.hadoop.hdfs.server.datanode.ReplicaNotFoundException;
 import org.apache.hadoop.hdfs.server.datanode.SecureDataNodeStarter;
 import org.apache.hadoop.hdfs.server.datanode.SecureDataNodeStarter.SecureResources;
 import org.apache.hadoop.hdfs.server.datanode.SimulatedFSDataset;
@@ -122,7 +122,6 @@ import org.apache.hadoop.test.GenericTestUtils;
 import org.apache.hadoop.util.ExitUtil;
 import org.apache.hadoop.util.ShutdownHookManager;
 import org.apache.hadoop.util.StringUtils;
-import org.apache.hadoop.util.ShutdownHookManager;
 import org.apache.hadoop.util.ToolRunner;
 
 import com.google.common.base.Joiner;
@@ -1823,7 +1822,29 @@ public class MiniDFSCluster {
   }
 
   /**
-   * Gets the rpc port used by the NameNode, because the caller 
+   * Returns the corresponding FsDatasetTestUtils for a DataNode.
+   * @param dnIdx the index of DataNode.
+   * @return a FsDatasetTestUtils for the given DataNode.
+   */
+  public FsDatasetTestUtils getFsDatasetTestUtils(int dnIdx) {
+    Preconditions.checkArgument(dnIdx < dataNodes.size());
+    return FsDatasetTestUtils.Factory.getFactory(conf)
+        .newInstance(dataNodes.get(dnIdx).datanode);
+  }
+
+  /**
+   * Returns the corresponding FsDatasetTestUtils for a DataNode.
+   * @param dn a DataNode
+   * @return a FsDatasetTestUtils for the given DataNode.
+   */
+  public FsDatasetTestUtils getFsDatasetTestUtils(DataNode dn) {
+    Preconditions.checkArgument(dn != null);
+    return FsDatasetTestUtils.Factory.getFactory(conf)
+        .newInstance(dn);
+  }
+
+  /**
+   * Gets the rpc port used by the NameNode, because the caller
    * supplied port is not necessarily the actual port used.
    * Assumption: cluster has a single namenode
    */     
@@ -2006,11 +2027,18 @@ public class MiniDFSCluster {
   private int corruptBlockOnDataNodesHelper(ExtendedBlock block,
       boolean deleteBlockFile) throws IOException {
     int blocksCorrupted = 0;
-    File[] blockFiles = getAllBlockFiles(block);
-    for (File f : blockFiles) {
-      if ((deleteBlockFile && corruptBlockByDeletingBlockFile(f)) ||
-          (!deleteBlockFile && corruptBlock(f))) {
+    for (DataNode dn : getDataNodes()) {
+      try {
+        MaterializedReplica replica =
+            getFsDatasetTestUtils(dn).getMaterializedReplica(block);
+        if (deleteBlockFile) {
+          replica.deleteData();
+        } else {
+          replica.corruptData();
+        }
         blocksCorrupted++;
+      } catch (ReplicaNotFoundException e) {
+        // Ignore.
       }
     }
     return blocksCorrupted;
@@ -2062,46 +2090,33 @@ public class MiniDFSCluster {
    *
    * @param i index of the datanode
    * @param blk name of the block
-   * @throws IOException on error accessing the given block or if
-   * the contents of the block (on the same datanode) differ.
-   * @return true if a replica was corrupted, false otherwise
-   * Types: delete, write bad data, truncate
+   * @throws IOException on error accessing the given block file.
    */
-  public boolean corruptReplica(int i, ExtendedBlock blk)
+  public void corruptReplica(int i, ExtendedBlock blk)
       throws IOException {
-    File blockFile = getBlockFile(i, blk);
-    return corruptBlock(blockFile);
+    getMaterializedReplica(i, blk).corruptData();
   }
 
-  /*
-   * Corrupt a block on a particular datanode
+  /**
+   * Corrupt a block on a particular datanode.
+   *
+   * @param dn the datanode
+   * @param blk name of the block
+   * @throws IOException on error accessing the given block file.
    */
-  public static boolean corruptBlock(File blockFile) throws IOException {
-    if (blockFile == null || !blockFile.exists()) {
-      return false;
-    }
-    // Corrupt replica by writing random bytes into replica
-    Random random = new Random();
-    RandomAccessFile raFile = new RandomAccessFile(blockFile, "rw");
-    FileChannel channel = raFile.getChannel();
-    String badString = "BADBAD";
-    int rand = random.nextInt((int)channel.size()/2);
-    raFile.seek(rand);
-    raFile.write(badString.getBytes());
-    raFile.close();
-    LOG.warn("Corrupting the block " + blockFile);
-    return true;
+  public void corruptReplica(DataNode dn, ExtendedBlock blk)
+      throws IOException {
+    getMaterializedReplica(dn, blk).corruptData();
   }
 
-  /*
-   * Corrupt a block on a particular datanode by deleting the block file
+  /**
+   * Corrupt the metadata of a block on a datanode.
+   * @param i the index of the datanode
+   * @param blk name of the block
+   * @throws IOException on error accessing the given metadata file.
    */
-  public static boolean corruptBlockByDeletingBlockFile(File blockFile) 
-      throws IOException {
-    if (blockFile == null || !blockFile.exists()) {
-      return false;
-    }
-    return blockFile.delete();
+  public void corruptMeta(int i, ExtendedBlock blk) throws IOException {
+    getMaterializedReplica(i, blk).corruptMeta();
   }
 
   public boolean changeGenStampOfBlock(int dnIndex, ExtendedBlock blk,
@@ -2757,7 +2772,33 @@ public class MiniDFSCluster {
     return new File(getBPDir(storageDir, bpid, Storage.STORAGE_DIR_CURRENT)
         + DataStorage.STORAGE_DIR_FINALIZED );
   }
-  
+
+  /**
+   * Get materialized replica that can be corrupted later.
+   * @param i the index of DataNode.
+   * @param blk name of the block.
+   * @return a materialized replica.
+   * @throws ReplicaNotFoundException if the replica does not exist on the
+   * DataNode.
+   */
+  public MaterializedReplica getMaterializedReplica(
+      int i, ExtendedBlock blk) throws ReplicaNotFoundException {
+    return getFsDatasetTestUtils(i).getMaterializedReplica(blk);
+  }
+
+  /**
+   * Get materialized replica that can be corrupted later.
+   * @param dn the index of DataNode.
+   * @param blk name of the block.
+   * @return a materialized replica.
+   * @throws ReplicaNotFoundException if the replica does not exist on the
+   * DataNode.
+   */
+  public MaterializedReplica getMaterializedReplica(
+      DataNode dn, ExtendedBlock blk) throws ReplicaNotFoundException {
+    return getFsDatasetTestUtils(dn).getMaterializedReplica(blk);
+  }
+
   /**
    * Get file correpsonding to a block
    * @param storageDir storage directory

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

@@ -18,11 +18,9 @@
 package org.apache.hadoop.hdfs;
 
 import java.io.ByteArrayOutputStream;
-import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.PrintStream;
-import java.io.RandomAccessFile;
 import java.util.Random;
 import java.util.concurrent.TimeoutException;
 
@@ -39,7 +37,6 @@ import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
 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.namenode.NamenodeFsck;
 import org.apache.hadoop.hdfs.tools.DFSck;
 import org.apache.hadoop.security.AccessControlException;
@@ -217,7 +214,7 @@ public class TestClientReportBadBlock {
     for (int i = 0; i < corruptBlockCount; i++) {
       DatanodeInfo dninfo = datanodeinfos[i];
       final DataNode dn = cluster.getDataNode(dninfo.getIpcPort());
-      corruptBlock(block, dn);
+      cluster.corruptReplica(dn, block);
       LOG.debug("Corrupted block " + block.getBlockName() + " on data node "
           + dninfo);
 
@@ -292,30 +289,6 @@ public class TestClientReportBadBlock {
     }
   }
 
-  /**
-   * Corrupt a block on a data node. Replace the block file content with content
-   * of 1, 2, ...BLOCK_SIZE.
-   * 
-   * @param block
-   *          the ExtendedBlock to be corrupted
-   * @param dn
-   *          the data node where the block needs to be corrupted
-   * @throws FileNotFoundException
-   * @throws IOException
-   */
-  private static void corruptBlock(final ExtendedBlock block, final DataNode dn)
-      throws FileNotFoundException, IOException {
-    final File f = DataNodeTestUtils.getBlockFile(
-        dn, block.getBlockPoolId(), block.getLocalBlock());
-    final RandomAccessFile raFile = new RandomAccessFile(f, "rw");
-    final byte[] bytes = new byte[(int) BLOCK_SIZE];
-    for (int i = 0; i < BLOCK_SIZE; i++) {
-      bytes[i] = (byte) (i);
-    }
-    raFile.write(bytes);
-    raFile.close();
-  }
-
   private static void verifyFsckHealth(String expected) throws Exception {
     // Fsck health has error code 0.
     // Make sure filesystem is in healthy state

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

@@ -39,8 +39,8 @@ import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.BlockListAsLongs;
-import org.apache.hadoop.hdfs.server.datanode.DataNode;
-import org.apache.hadoop.hdfs.server.datanode.DataNodeTestUtils;
+import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
+import org.apache.hadoop.hdfs.server.datanode.FsDatasetTestUtils.MaterializedReplica;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeStorage;
 import org.apache.hadoop.hdfs.tools.DFSAdmin;
 import org.apache.hadoop.io.IOUtils;
@@ -1507,32 +1507,31 @@ public class TestDFSShell {
     }
   }
 
-  static List<File> getBlockFiles(MiniDFSCluster cluster) throws IOException {
-    List<File> files = new ArrayList<File>();
-    List<DataNode> datanodes = cluster.getDataNodes();
+  private static List<MaterializedReplica> getMaterializedReplicas(
+      MiniDFSCluster cluster) throws IOException {
+    List<MaterializedReplica> replicas = new ArrayList<>();
     String poolId = cluster.getNamesystem().getBlockPoolId();
-    List<Map<DatanodeStorage, BlockListAsLongs>> blocks = cluster.getAllBlockReports(poolId);
+    List<Map<DatanodeStorage, BlockListAsLongs>> blocks =
+        cluster.getAllBlockReports(poolId);
     for(int i = 0; i < blocks.size(); i++) {
-      DataNode dn = datanodes.get(i);
       Map<DatanodeStorage, BlockListAsLongs> map = blocks.get(i);
       for(Map.Entry<DatanodeStorage, BlockListAsLongs> e : map.entrySet()) {
         for(Block b : e.getValue()) {
-          files.add(DataNodeTestUtils.getFile(dn, poolId, b.getBlockId()));
+          replicas.add(cluster.getMaterializedReplica(i,
+              new ExtendedBlock(poolId, b)));
         }
       }
     }
-    return files;
+    return replicas;
   }
 
-  static void corrupt(List<File> files) throws IOException {
-    for(File f : files) {
-      StringBuilder content = new StringBuilder(DFSTestUtil.readFile(f));
-      char c = content.charAt(0);
-      content.setCharAt(0, ++c);
-      PrintWriter out = new PrintWriter(f);
-      out.print(content);
-      out.flush();
-      out.close();
+  private static void corrupt(
+      List<MaterializedReplica> replicas, String content) throws IOException {
+    StringBuilder sb = new StringBuilder(content);
+    char c = content.charAt(0);
+    sb.setCharAt(0, ++c);
+    for(MaterializedReplica replica : replicas) {
+      replica.corruptData(sb.toString().getBytes("UTF8"));
     }
   }
 
@@ -1636,7 +1635,7 @@ public class TestDFSShell {
       assertEquals(localfcontent, runner.run(0, "-ignoreCrc"));
 
       // find block files to modify later
-      List<File> files = getBlockFiles(cluster);
+      List<MaterializedReplica> replicas = getMaterializedReplicas(cluster);
 
       // Shut down cluster and then corrupt the block files by overwriting a
       // portion with junk data.  We must shut down the cluster so that threads
@@ -1649,8 +1648,8 @@ public class TestDFSShell {
       dfs.close();
       cluster.shutdown();
 
-      show("files=" + files);
-      corrupt(files);
+      show("replicas=" + replicas);
+      corrupt(replicas, localfcontent);
 
       // Start the cluster again, but do not reformat, so prior files remain.
       cluster = new MiniDFSCluster.Builder(conf).numDataNodes(2).format(false)

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileAppend3.java

@@ -21,20 +21,18 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
-import java.io.File;
 import java.io.IOException;
-import java.io.RandomAccessFile;
 import java.util.EnumSet;
 import java.util.List;
 
 import org.apache.hadoop.fs.CreateFlag;
+import org.apache.hadoop.hdfs.server.datanode.FsDatasetTestUtils.MaterializedReplica;
 import org.apache.hadoop.test.GenericTestUtils;
 import org.mockito.invocation.InvocationOnMock;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.when;
 import org.mockito.stubbing.Answer;
 
-import org.apache.commons.logging.impl.Log4JLogger;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.CommonConfigurationKeys;
 import org.apache.hadoop.fs.FSDataOutputStream;
@@ -315,13 +313,7 @@ public class TestFileAppend3  {
     DatanodeInfo[] datanodeinfos = lb.getLocations();
     assertEquals(repl, datanodeinfos.length);
     final DataNode dn = cluster.getDataNode(datanodeinfos[0].getIpcPort());
-    final File f = DataNodeTestUtils.getBlockFile(
-        dn, blk.getBlockPoolId(), blk.getLocalBlock());
-    final RandomAccessFile raf = new RandomAccessFile(f, "rw");
-    AppendTestUtil.LOG.info("dn=" + dn + ", blk=" + blk + " (length=" + blk.getNumBytes() + ")");
-    assertEquals(len1, raf.length());
-    raf.setLength(0);
-    raf.close();
+    cluster.getMaterializedReplica(dn, blk).truncateData(0);
 
     //c. Open file in "append mode".  Append a new block worth of data. Close file.
     final int len2 = (int)BLOCK_SIZE; 

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

@@ -81,7 +81,7 @@ public class TestMissingBlocksAlert {
 
       // Corrupt the block
       ExtendedBlock block = DFSTestUtil.getFirstBlock(dfs, corruptFile);
-      assertTrue(cluster.corruptReplica(0, block));
+      cluster.corruptReplica(0, block);
 
       // read the file so that the corrupt block is reported to NN
       FSDataInputStream in = dfs.open(corruptFile); 
@@ -126,7 +126,7 @@ public class TestMissingBlocksAlert {
       DFSTestUtil.createFile(dfs, replOneFile, fileLen, (short)1, 0);
       ExtendedBlock replOneBlock = DFSTestUtil.getFirstBlock(
           dfs, replOneFile);
-      assertTrue(cluster.corruptReplica(0, replOneBlock));
+      cluster.corruptReplica(0, replOneBlock);
 
       // read the file so that the corrupt block is reported to NN
       in = dfs.open(replOneFile);

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestBlocksWithNotEnoughRacks.java

@@ -210,7 +210,7 @@ public class TestBlocksWithNotEnoughRacks {
 
       // Corrupt a replica of the block
       int dnToCorrupt = DFSTestUtil.firstDnWithBlock(cluster, b);
-      assertTrue(cluster.corruptReplica(dnToCorrupt, b));
+      cluster.corruptReplica(dnToCorrupt, b);
 
       // Restart the datanode so blocks are re-scanned, and the corrupt
       // block is detected.

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestOverReplicatedBlocks.java

@@ -67,7 +67,7 @@ public class TestOverReplicatedBlocks {
       
       // corrupt the block on datanode 0
       ExtendedBlock block = DFSTestUtil.getFirstBlock(fs, fileName);
-      assertTrue(cluster.corruptReplica(0, block));
+      cluster.corruptReplica(0, block);
       DataNodeProperties dnProps = cluster.stopDataNode(0);
       // remove block scanner log to trigger block scanning
       File scanCursor = new File(new File(MiniDFSCluster.getFinalizedDir(

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestRBWBlockInvalidation.java

@@ -22,7 +22,6 @@ import static org.junit.Assert.assertTrue;
 import static org.junit.Assume.assumeTrue;
 
 import java.io.Closeable;
-import java.io.File;
 import java.io.IOException;
 import java.util.List;
 
@@ -37,10 +36,8 @@ import org.apache.hadoop.hdfs.DFSTestUtil;
 import org.apache.hadoop.hdfs.HdfsConfiguration;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
 import org.apache.hadoop.hdfs.MiniDFSCluster.DataNodeProperties;
-import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
-import org.apache.hadoop.hdfs.server.datanode.DataNode;
-import org.apache.hadoop.hdfs.server.datanode.DataNodeTestUtils;
+import org.apache.hadoop.hdfs.server.datanode.FsDatasetTestUtils.MaterializedReplica;
 import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
 import org.apache.hadoop.hdfs.server.namenode.ha.HATestUtil;
 import org.apache.hadoop.hdfs.server.namenode.ha.TestDNFencing.RandomDeleterPolicy;
@@ -91,19 +88,14 @@ public class TestRBWBlockInvalidation {
       out.writeBytes("HDFS-3157: " + testPath);
       out.hsync();
       cluster.startDataNodes(conf, 1, true, null, null, null);
-      String bpid = namesystem.getBlockPoolId();
       ExtendedBlock blk = DFSTestUtil.getFirstBlock(fs, testPath);
-      Block block = blk.getLocalBlock();
-      DataNode dn = cluster.getDataNodes().get(0);
 
       // Delete partial block and its meta information from the RBW folder
       // of first datanode.
-      File blockFile = DataNodeTestUtils.getBlockFile(dn, bpid, block);
-      File metaFile = DataNodeTestUtils.getMetaFile(dn, bpid, block);
-      assertTrue("Could not delete the block file from the RBW folder",
-          blockFile.delete());
-      assertTrue("Could not delete the block meta file from the RBW folder",
-          metaFile.delete());
+      MaterializedReplica replica = cluster.getMaterializedReplica(0, blk);
+
+      replica.deleteData();
+      replica.deleteMeta();
 
       out.close();
       

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/DataNodeTestUtils.java

@@ -158,20 +158,6 @@ public class DataNodeTestUtils {
     return dn.getFSDataset();
   }
 
-  public static File getFile(DataNode dn, String bpid, long bid) {
-    return FsDatasetTestUtil.getFile(dn.getFSDataset(), bpid, bid);
-  }
-
-  public static File getBlockFile(DataNode dn, String bpid, Block b
-      ) throws IOException {
-    return FsDatasetTestUtil.getBlockFile(dn.getFSDataset(), bpid, b);
-  }
-
-  public static File getMetaFile(DataNode dn, String bpid, Block b)
-      throws IOException {
-    return FsDatasetTestUtil.getMetaFile(dn.getFSDataset(), bpid, b);
-  }
-
   public static long getPendingAsyncDeletions(DataNode dn) {
     return FsDatasetTestUtil.getPendingAsyncDeletions(dn.getFSDataset());
   }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/FsDatasetImplTestUtilsFactory.java

@@ -0,0 +1,32 @@
+/**
+ * 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.datanode;
+
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetImplTestUtils;
+
+/**
+ * A factory for creating {@link FsDatasetImplTestUtils} objects.
+ */
+public final class FsDatasetImplTestUtilsFactory
+    extends FsDatasetTestUtils.Factory<FsDatasetTestUtils> {
+  @Override
+  public FsDatasetTestUtils newInstance(DataNode datanode) {
+    return new FsDatasetImplTestUtils(datanode);
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/FsDatasetTestUtils.java

@@ -0,0 +1,140 @@
+/**
+ * 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.datanode;
+
+import com.google.common.base.Preconditions;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetFactory;
+import org.apache.hadoop.util.ReflectionUtils;
+
+import java.io.FileNotFoundException;
+import java.io.IOException;
+
+/**
+ * Provide block access for FsDataset white box tests.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
+public interface FsDatasetTestUtils {
+
+  abstract class Factory<D extends FsDatasetTestUtils> {
+    /**
+     * By default, it returns FsDatasetImplTestUtilsFactory.
+     *
+     * @return The configured Factory.
+     */
+    public static Factory<?> getFactory(Configuration conf) {
+      String className = conf.get(
+          DFSConfigKeys.DFS_DATANODE_FSDATASET_FACTORY_KEY,
+          FsDatasetFactory.class.getName());
+      Preconditions.checkState(className.contains("Factory"));
+      className = className.replaceFirst("(\\$)?Factory$", "TestUtilsFactory");
+      final Class<? extends Factory> clazz = conf.getClass(
+          className,
+          FsDatasetImplTestUtilsFactory.class,
+          Factory.class);
+      return ReflectionUtils.newInstance(clazz, conf);
+    }
+
+    /**
+     * Create a new instance of FsDatasetTestUtils.
+     */
+    public abstract D newInstance(DataNode datanode);
+
+    /**
+     * @return True for SimulatedFsDataset
+     */
+    public boolean isSimulated() {
+      return false;
+    }
+  }
+
+  /**
+   * A replica to be corrupted.
+   *
+   * It is safe to corrupt this replica even if the MiniDFSCluster is shutdown.
+   */
+  interface MaterializedReplica {
+
+    /**
+     * Corrupt the block file of the replica.
+     * @throws FileNotFoundException if the block file does not exist.
+     * @throws IOException if I/O error.
+     */
+    void corruptData() throws IOException;
+
+    /**
+     * Corrupt the block file with the given content.
+     * @param newContent the new content written to the block file.
+     * @throws FileNotFoundException if the block file does not exist.
+     * @throws IOException if I/O error.
+     */
+    void corruptData(byte[] newContent) throws IOException;
+
+    /**
+     * Truncate the block file of the replica to the newSize.
+     * @param newSize the new size of the block file.
+     * @throws FileNotFoundException if the block file does not exist.
+     * @throws IOException if I/O error.
+     */
+    void truncateData(long newSize) throws IOException;
+
+    /**
+     * Delete the block file of the replica.
+     * @throws FileNotFoundException if the block file does not exist.
+     * @throws IOException if I/O error.
+     */
+    void deleteData() throws IOException;
+
+    /**
+     * Corrupt the metadata file of the replica.
+     * @throws FileNotFoundException if the block file does not exist.
+     * @throws IOException if I/O error.
+     */
+    void corruptMeta() throws IOException;
+
+    /**
+     * Delete the metadata file of the replcia.
+     * @throws FileNotFoundException if the block file does not exist.
+     * @throws IOException I/O error.
+     */
+    void deleteMeta() throws IOException;
+
+    /**
+     * Truncate the metadata file of the replica to the newSize.
+     * @throws FileNotFoundException if the block file does not exist.
+     * @throws IOException I/O error.
+     */
+    void truncateMeta(long newSize) throws IOException;
+  }
+
+  /**
+   * Get a materialized replica to corrupt its block / crc later.
+   * @param block the block of this replica begone to.
+   * @return a replica to corrupt. Return null if the replica does not exist
+   * in this dataset.
+   * @throws ReplicaNotFoundException if the replica does not exists on the
+   *         dataset.
+   */
+  MaterializedReplica getMaterializedReplica(ExtendedBlock block)
+          throws ReplicaNotFoundException;
+}

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsDatasetImplTestUtils.java

@@ -0,0 +1,179 @@
+/**
+ * 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.datanode.fsdataset.impl;
+
+import com.google.common.base.Preconditions;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
+import org.apache.hadoop.hdfs.server.datanode.DataNode;
+import org.apache.hadoop.hdfs.server.datanode.FsDatasetTestUtils;
+import org.apache.hadoop.hdfs.server.datanode.ReplicaNotFoundException;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.nio.channels.FileChannel;
+import java.nio.file.Files;
+import java.util.Random;
+
+/**
+ * Test-related utilities to access blocks in {@link FsDatasetImpl}.
+ */
+@InterfaceStability.Unstable
+@InterfaceAudience.Private
+public class FsDatasetImplTestUtils implements FsDatasetTestUtils {
+  private static final Log LOG =
+      LogFactory.getLog(FsDatasetImplTestUtils.class);
+  private final FsDatasetImpl dataset;
+
+  /**
+   * A reference to the replica that is used to corrupt block / meta later.
+   */
+  private static class FsDatasetImplMaterializedReplica
+      implements MaterializedReplica {
+    /** Block file of the replica. */
+    private final File blockFile;
+    private final File metaFile;
+
+    /** Check the existence of the file. */
+    private static void checkFile(File file) throws FileNotFoundException {
+      if (file == null || !file.exists()) {
+        throw new FileNotFoundException(
+            "The block file or metadata file " + file + " does not exist.");
+      }
+    }
+
+    /** Corrupt a block / crc file by truncating it to a newSize */
+    private static void truncate(File file, long newSize)
+        throws IOException {
+      Preconditions.checkArgument(newSize >= 0);
+      checkFile(file);
+      try (RandomAccessFile raf = new RandomAccessFile(file, "rw")) {
+        raf.setLength(newSize);
+      }
+    }
+
+    /** Corrupt a block / crc file by deleting it. */
+    private static void delete(File file) throws IOException {
+      checkFile(file);
+      Files.delete(file.toPath());
+    }
+
+    FsDatasetImplMaterializedReplica(File blockFile, File metaFile) {
+      this.blockFile = blockFile;
+      this.metaFile = metaFile;
+    }
+
+    @Override
+    public void corruptData() throws IOException {
+      checkFile(blockFile);
+      LOG.info("Corrupting block file: " + blockFile);
+      final int BUF_SIZE = 32;
+      byte[] buf = new byte[BUF_SIZE];
+      try (RandomAccessFile raf = new RandomAccessFile(blockFile, "rw")) {
+        int nread = raf.read(buf);
+        for (int i = 0; i < nread; i++) {
+          buf[i]++;
+        }
+        raf.seek(0);
+        raf.write(buf);
+      }
+    }
+
+    @Override
+    public void corruptData(byte[] newContent) throws IOException {
+      checkFile(blockFile);
+      LOG.info("Corrupting block file with new content: " + blockFile);
+      try (RandomAccessFile raf = new RandomAccessFile(blockFile, "rw")) {
+        raf.write(newContent);
+      }
+    }
+
+    @Override
+    public void truncateData(long newSize) throws IOException {
+      LOG.info("Truncating block file: " + blockFile);
+      truncate(blockFile, newSize);
+    }
+
+    @Override
+    public void deleteData() throws IOException {
+      LOG.info("Deleting block file: " + blockFile);
+      delete(blockFile);
+    }
+
+    @Override
+    public void corruptMeta() throws IOException {
+      checkFile(metaFile);
+      LOG.info("Corrupting meta file: " + metaFile);
+      Random random = new Random();
+      try (RandomAccessFile raf = new RandomAccessFile(metaFile, "rw")) {
+        FileChannel channel = raf.getChannel();
+        int offset = random.nextInt((int)channel.size() / 2);
+        raf.seek(offset);
+        raf.write("BADBAD".getBytes());
+      }
+    }
+
+    @Override
+    public void deleteMeta() throws IOException {
+      LOG.info("Deleting metadata file: " + metaFile);
+      delete(metaFile);
+    }
+
+    @Override
+    public void truncateMeta(long newSize) throws IOException {
+      LOG.info("Truncating metadata file: " + metaFile);
+      truncate(metaFile, newSize);
+    }
+
+    @Override
+    public String toString() {
+      return String.format("MaterializedReplica: file=%s", blockFile);
+    }
+  }
+
+  public FsDatasetImplTestUtils(DataNode datanode) {
+    Preconditions.checkArgument(
+        datanode.getFSDataset() instanceof FsDatasetImpl);
+    dataset = (FsDatasetImpl) datanode.getFSDataset();
+  }
+
+  /**
+   * Return a materialized replica from the FsDatasetImpl.
+   */
+  @Override
+  public MaterializedReplica getMaterializedReplica(ExtendedBlock block)
+      throws ReplicaNotFoundException {
+    File blockFile;
+    try {
+       blockFile = dataset.getBlockFile(
+           block.getBlockPoolId(), block.getBlockId());
+    } catch (IOException e) {
+      LOG.error("Block file for " + block + " does not existed:", e);
+      throw new ReplicaNotFoundException(block);
+    }
+    File metaFile = FsDatasetUtil.getMetaFile(
+        blockFile, block.getGenerationStamp());
+    return new FsDatasetImplMaterializedReplica(blockFile, metaFile);
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/TestScrLazyPersistFiles.java

@@ -19,12 +19,9 @@ package org.apache.hadoop.hdfs.server.datanode.fsdataset.impl;
 import com.google.common.base.Preconditions;
 import org.apache.commons.io.IOUtils;
 import org.apache.hadoop.fs.ChecksumException;
-import org.apache.hadoop.fs.FSDataInputStream;
 import org.apache.hadoop.fs.Path;
-import org.apache.hadoop.fs.StorageType;
 import org.apache.hadoop.hdfs.ClientContext;
 import org.apache.hadoop.hdfs.DFSTestUtil;
-import org.apache.hadoop.hdfs.MiniDFSCluster;
 import org.apache.hadoop.hdfs.client.HdfsDataInputStream;
 import org.apache.hadoop.hdfs.server.datanode.BlockMetadataHeader;
 import org.apache.hadoop.io.nativeio.NativeIO;
@@ -264,9 +261,7 @@ public class TestScrLazyPersistFiles extends LazyPersistTestCase {
     // Corrupt the lazy-persisted checksum file, and verify that checksum
     // verification catches it.
     ensureFileReplicasOnStorageType(path1, DEFAULT);
-    File metaFile = cluster.getBlockMetadataFile(0,
-        DFSTestUtil.getFirstBlock(fs, path1));
-    MiniDFSCluster.corruptBlock(metaFile);
+    cluster.corruptMeta(0, DFSTestUtil.getFirstBlock(fs, path1));
     exception.expect(ChecksumException.class);
     DFSTestUtil.readFileBuffer(fs, path1);
   }

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

@@ -268,10 +268,12 @@ public class TestProcessCorruptBlocks {
 
   private void corruptBlock(MiniDFSCluster cluster, FileSystem fs, final Path fileName,
       int dnIndex, ExtendedBlock block) throws IOException {
-    // corrupt the block on datanode dnIndex
+    // Truncate the block on the first datanode that has not been corrupted,
+    // so that directory scanner can discover the corruption from file size
+    // change.
     // the indexes change once the nodes are restarted.
     // But the datadirectory will not change
-    assertTrue(cluster.corruptReplica(dnIndex, block));
+    cluster.getMaterializedReplica(0, block).truncateData(10);
 
     // Run directory scanner to update the DN's volume map  
     DataNodeTestUtils.runDirectoryScanner(cluster.getDataNodes().get(0));