HDFS-9958. BlockManager#createLocatedBlocks can throw NPE for corruptBlocks on failed storages. Contributed by Kuhu Shukla.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java

@@ -953,8 +953,8 @@ public class BlockManager implements BlockStatsMXBean {
     }
 
     final int numNodes = blocksMap.numNodes(blk);
-    final boolean isCorrupt = numCorruptNodes == numNodes;
-    final int numMachines = isCorrupt ? numNodes: numNodes - numCorruptNodes;
+    final boolean isCorrupt = numCorruptReplicas == numNodes;
+    final int numMachines = isCorrupt ? numNodes: numNodes - numCorruptReplicas;
     final DatanodeStorageInfo[] machines = new DatanodeStorageInfo[numMachines];
     int j = 0;
     if (numMachines > 0) {
@@ -1232,11 +1232,23 @@ public class BlockManager implements BlockStatsMXBean {
           + " as corrupt because datanode " + dn + " (" + dn.getDatanodeUuid()
           + ") does not exist");
     }
-    
+
+    DatanodeStorageInfo storage = null;
+    if (storageID != null) {
+      storage = node.getStorageInfo(storageID);
+    }
+    if (storage == null) {
+      storage = storedBlock.findStorageInfo(node);
+    }
+
+    if (storage == null) {
+      blockLog.debug("BLOCK* findAndMarkBlockAsCorrupt: {} not found on {}",
+          blk, dn);
+      return;
+    }
     markBlockAsCorrupt(new BlockToMarkCorrupt(storedBlock,
             blk.getGenerationStamp(), reason, Reason.CORRUPTION_REPORTED),
-        storageID == null ? null : node.getStorageInfo(storageID),
-        node);
+        storage, node);
   }
 
   /**

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

@@ -18,15 +18,22 @@
 
 package org.apache.hadoop.hdfs;
 
+import org.apache.hadoop.fs.StorageType;
+import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeStorageInfo;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
+import java.io.File;
+import java.io.IOException;
 import java.io.FileOutputStream;
 import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.Map;
+import java.util.Random;
+import java.util.Set;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.ChecksumException;
@@ -36,6 +43,8 @@ import org.apache.hadoop.hdfs.protocol.BlockListAsLongs;
 import org.apache.hadoop.hdfs.protocol.BlockListAsLongs.BlockReportReplica;
 import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
+import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
 import org.apache.hadoop.hdfs.server.datanode.DataNode;
 import org.apache.hadoop.hdfs.server.datanode.DataNodeTestUtils;
 import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
@@ -167,7 +176,83 @@ public class TestFileCorruption {
       }
     }
   }
-  
+
+  @Test
+  public void testCorruptionWithDiskFailure() throws Exception {
+    MiniDFSCluster cluster = null;
+    try {
+      Configuration conf = new HdfsConfiguration();
+      cluster = new MiniDFSCluster.Builder(conf).numDataNodes(3).build();
+      cluster.waitActive();
+      BlockManager bm = cluster.getNamesystem().getBlockManager();
+      FileSystem fs = cluster.getFileSystem();
+      final Path FILE_PATH = new Path("/tmp.txt");
+      final long FILE_LEN = 1L;
+      DFSTestUtil.createFile(fs, FILE_PATH, FILE_LEN, (short) 3, 1L);
+
+      // get the block
+      final String bpid = cluster.getNamesystem().getBlockPoolId();
+      File storageDir = cluster.getInstanceStorageDir(0, 0);
+      File dataDir = MiniDFSCluster.getFinalizedDir(storageDir, bpid);
+      assertTrue("Data directory does not exist", dataDir.exists());
+      ExtendedBlock blk = getFirstBlock(cluster.getDataNodes().get(0), bpid);
+      if (blk == null) {
+        blk = getFirstBlock(cluster.getDataNodes().get(0), bpid);
+      }
+      assertFalse("Data directory does not contain any blocks or there was an" +
+          " " +
+          "IO error", blk == null);
+      ArrayList<DataNode> datanodes = cluster.getDataNodes();
+      assertEquals(datanodes.size(), 3);
+      FSNamesystem ns = cluster.getNamesystem();
+      //fail the storage on that node which has the block
+      try {
+        ns.writeLock();
+        updateAllStorages(bm);
+      } finally {
+        ns.writeUnlock();
+      }
+      ns.writeLock();
+      try {
+        markAllBlocksAsCorrupt(bm, blk);
+      } finally {
+        ns.writeUnlock();
+      }
+
+      // open the file
+      fs.open(FILE_PATH);
+
+      //clean up
+      fs.delete(FILE_PATH, false);
+    } finally {
+      if (cluster != null) { cluster.shutdown(); }
+    }
+
+  }
+
+  private void markAllBlocksAsCorrupt(BlockManager bm,
+                                      ExtendedBlock blk) throws IOException {
+    for (DatanodeStorageInfo info : bm.getStorages(blk.getLocalBlock())) {
+      bm.findAndMarkBlockAsCorrupt(
+          blk, info.getDatanodeDescriptor(), info.getStorageID(), "STORAGE_ID");
+    }
+  }
+
+  private void updateAllStorages(BlockManager bm) {
+    for (DatanodeDescriptor dd : bm.getDatanodeManager().getDatanodes()) {
+      Set<DatanodeStorageInfo> setInfos = new HashSet<DatanodeStorageInfo>();
+      DatanodeStorageInfo[] infos = dd.getStorageInfos();
+      Random random = new Random();
+      for (int i = 0; i < infos.length; i++) {
+        int blkId = random.nextInt(101);
+        DatanodeStorage storage = new DatanodeStorage(Integer.toString(blkId),
+            DatanodeStorage.State.FAILED, StorageType.DISK);
+        infos[i].updateFromStorage(storage);
+        setInfos.add(infos[i]);
+      }
+    }
+  }
+
   private static ExtendedBlock getFirstBlock(DataNode dn, String bpid) {
     Map<DatanodeStorage, BlockListAsLongs> blockReports =
         dn.getFSDataset().getBlockReports(bpid);