merge -r 807432:807431 to revert the change made to the append branch by HDFS-553

git-svn-id: https://svn.apache.org/repos/asf/hadoop/hdfs/branches/HDFS-265@807436 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -166,9 +166,6 @@ Trunk (unreleased changes)
     HDFS-547. TestHDFSFileSystemContract#testOutputStreamClosedTwice
     sometimes fails with CloseByInterruptException. (hairong)
 
-    HDFS-553. BlockSender reports wrong failed position in ChecksumException.
-    (hairong)
-
 Release 0.20.1 - Unreleased
 
   IMPROVEMENTS

src/java/org/apache/hadoop/hdfs/server/datanode/BlockSender.java

@@ -290,9 +290,8 @@ class BlockSender implements java.io.Closeable, FSConstants {
           int dLen = Math.min(dLeft, bytesPerChecksum);
           checksum.update(buf, dOff, dLen);
           if (!checksum.compare(buf, cOff)) {
-            long failedPos = offset + len -dLeft;
             throw new ChecksumException("Checksum failed at " + 
-                                        failedPos, failedPos);
+                                        (offset + len - dLeft), len);
           }
           dLeft -= dLen;
           dOff += dLen;