HDFS-5337. Merging change r1530836 from branch-2

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.2@1530837 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs-nfs/src/main/java/org/apache/hadoop/hdfs/nfs/nfs3/OpenFileCtx.java

@@ -712,7 +712,8 @@ class OpenFileCtx {
       LOG.debug("Got commit status: " + ret.name());
     }
     // Do the sync outside the lock
-    if (ret == COMMIT_STATUS.COMMIT_DO_SYNC) {
+    if (ret == COMMIT_STATUS.COMMIT_DO_SYNC
+        || ret == COMMIT_STATUS.COMMIT_FINISHED) {
       try {
         // Sync file data and length
         fos.hsync(EnumSet.of(SyncFlag.UPDATE_LENGTH));

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -27,6 +27,9 @@ Release 2.2.1 - UNRELEASED
 
     HDFS-5281. COMMIT request should not block. (brandonli)
 
+    HDFS-5337. should do hsync for a commit request even there is no pending
+    writes (brandonli)
+
 Release 2.2.0 - 2013-10-13
 
   INCOMPATIBLE CHANGES