HDFS-8665. Fix replication check in DFSTestUtils#waitForReplication.

Author: umbrant

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

@@ -672,6 +672,8 @@ Release 2.8.0 - UNRELEASED
     HDFS-8640. Make reserved RBW space visible through JMX. (kanaka kumar
     avvaru via Arpit Agarwal)
 
+    HDFS-8665. Fix replication check in DFSTestUtils#waitForReplication. (wang)
+
   OPTIMIZATIONS
 
     HDFS-8026. Trace FSOutputSummer#writeChecksumChunks rather than

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/DFSTestUtil.java

@@ -535,7 +535,14 @@ public static void waitForReplication(final DistributedFileSystem dfs,
       public Boolean get() {
         try {
           FileStatus stat = dfs.getFileStatus(file);
-          return replication == stat.getReplication();
+          BlockLocation[] locs = dfs.getFileBlockLocations(stat, 0, stat
+              .getLen());
+          for (BlockLocation loc : locs) {
+            if (replication != loc.getHosts().length) {
+              return false;
+            }
+          }
+          return true;
         } catch (IOException e) {
           LOG.info("getFileStatus on path " + file + " failed!", e);
           return false;