HDFS-15074. DataNode.DataTransfer thread should catch all the expception and log it. Contributed by hemanthboyina.

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

@@ -2624,6 +2624,8 @@ public void run() {
         handleBadBlock(b, ie, false);
         LOG.warn("{}:Failed to transfer {} to {} got",
             bpReg, b, targets[0], ie);
+      } catch (Throwable t) {
+        LOG.error("Failed to transfer block " + b, t);
       } finally {
         decrementXmitsInProgress();
         IOUtils.closeStream(blockSender);