code: public LocatedBlocks getBlockLocations(String src, long offset, long length) throws IOException {
      INode[] inodes = dir.getExistingPathINodes(src);
      return getBlockLocations(src, inodes[inodes.length-1],
          offset, length, false, BlockMetaInfoType.NONE);
    }
docs: Get block locations within the specified range.
  
  @see ClientProtocol#getBlockLocations(String, long, long)