add_block_entry
be = add_block_entry(fs_info, bytenr, fs_info->nodesize, ref_root);
be = add_block_entry(fs_info, bytenr, num_bytes, 0);
be = add_block_entry(fs_info, bytenr, num_bytes, ref_root);
be = add_block_entry(fs_info, bytenr, num_bytes, ref_root);