HDFS-17298. Fix NPE in DataNode.handleBadBlock and BlockSender (#6374)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BlockSender.java

@@ -41,6 +41,7 @@ import org.apache.hadoop.hdfs.protocol.datatransfer.PacketHeader;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.ReplicaState;
 import org.apache.hadoop.hdfs.server.common.DataNodeLockManager.LockLevel;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeReference;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeSpi;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.LengthInputStream;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.ReplicaInputStreams;
 import org.apache.hadoop.hdfs.util.DataTransferThrottler;
@@ -295,7 +296,12 @@ class BlockSender implements java.io.Closeable {
         (!is32Bit || length <= Integer.MAX_VALUE);
 
       // Obtain a reference before reading data
-      volumeRef = datanode.data.getVolume(block).obtainReference();
+      FsVolumeSpi volume = datanode.data.getVolume(block);
+      if (volume == null) {
+        LOG.warn("Cannot find FsVolumeSpi to obtain a reference for block: {}", block);
+        throw new ReplicaNotFoundException(block);
+      }
+      volumeRef = volume.obtainReference();
 
       /* 
        * (corruptChecksumOK, meta_file_exist): operation

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java

@@ -4107,8 +4107,12 @@ public class DataNode extends ReconfigurableBase
       return;
     }
     if (!fromScanner && blockScanner.isEnabled()) {
-      blockScanner.markSuspectBlock(data.getVolume(block).getStorageID(),
-          block);
+      FsVolumeSpi volume = data.getVolume(block);
+      if (volume == null) {
+        LOG.warn("Cannot find FsVolumeSpi to handle bad block: {}", block);
+        return;
+      }
+      blockScanner.markSuspectBlock(volume.getStorageID(), block);
     } else {
       try {
         reportBadBlocks(block);