cluster = new MiniDFSCluster.Builder(conf).numDataNodes(1).build();
cluster.waitActive();
final DistributedFileSystem hdfs = cluster.getFileSystem();
final FSDirectory fsdir = cluster.getNamesystem().getFSDirectory();
hdfs.mkdirs(new Path("/tmp"));
DFSTestUtil.createFile(hdfs, new Path("/tmp/f1"), 0, (short) 1, 0);
DFSTestUtil.createFile(hdfs, new Path("/tmp/f2"), 0, (short) 1, 0);
DFSTestUtil.createFile(hdfs, new Path("/tmp/f3"), 0, (short) 1, 0);
DirectoryListing dl = cluster.getNameNodeRpc().getListing("/tmp",