HRegionWALFileSystem getRegionWALFileSystem() throws IOException {
    return new HRegionWALFileSystem(conf, getWalFileSystem(),
      CommonFSUtils.getWALTableDir(conf, htableDescriptor.getTableName()), fs.getRegionInfo());
  }
Returns the WAL {@link HRegionFileSystem} used by this region
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java