HDFS-12293. DataNode should log file name on disk error. Contributed by Ajay Kumar.

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

@@ -284,7 +284,8 @@ class BlockReceiver implements Closeable {
       
       // check if there is a disk error
       IOException cause = DatanodeUtil.getCauseIfDiskError(ioe);
-      DataNode.LOG.warn("IOException in BlockReceiver constructor"
+      DataNode.LOG
+          .warn("IOException in BlockReceiver constructor :" + ioe.getMessage()
           + (cause == null ? "" : ". Cause is "), cause);
       if (cause != null) {
         ioe = cause;

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

@@ -2554,7 +2554,8 @@ public class DataNode extends ReconfigurableBase
         // disk check moved to FileIoProvider
         IOException cause = DatanodeUtil.getCauseIfDiskError(ie);
         if (cause != null) { // possible disk error
-          LOG.warn("IOException in DataTransfer#run(). Cause is ", cause);
+          LOG.warn("IOException in DataTransfer#run() "+ ie.getMessage() +". "
+                  + "Cause is ", cause);
         }
       } finally {
         decrementXmitsInProgress();