code: BlockInfo addINodeForLoading(Block b, INodeFile iNode) {
      // allocate new block when loading the image
      // for hardlinked files, we need to check if the blocks are already there
      BlockInfo info = checkBlockInfo(b, iNode.getReplication(),
          iNode.isHardlinkFile());
      info.inode = iNode;
      return info;
    }
docs: Add block b belonging to the specified file inode to the map.
  Does not check for block existence, for non-hardlinked files.