HDFS-16318. Add exception blockinfo

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSInputStream.java

@@ -257,7 +257,7 @@ void openInfo(boolean refreshLocatedBlocks) throws IOException {
         // locations will not be available with NN for getting the length. Lets
         // retry for 3 times to get the length.
         if (lastBlockBeingWrittenLength == -1) {
-          DFSClient.LOG.warn("Last block locations not available. "
+          DFSClient.LOG.warn("Last block locations " + getCurrentBlock() + " not available. "
               + "Datanodes might not have reported blocks completely."
               + " Will retry for " + retriesForLastBlockLength + " times");
           waitFor(conf.getRetryIntervalForGetLastBlockLength());