Re: [PATCH 1/8] mm: implement cleancache

[Suren Baghdasaryan <surenb@google.com>]

On Fri, Oct 10, 2025 at 2:18 PM kernel test robot <lkp@intel.com> wrote:
>
> Hi Suren,
>
> kernel test robot noticed the following build errors:
>
> [auto build test ERROR on 70478cb9da6fc4e7b987219173ba1681d5f7dd3d]
>
> url:    https://github.com/intel-lab-lkp/linux/commits/Suren-Baghdasaryan/mm-implement-cleancache/20251010-134501
> base:   70478cb9da6fc4e7b987219173ba1681d5f7dd3d
> patch link:    https://lore.kernel.org/r/20251010011951.2136980-2-surenb%40google.com
> patch subject: [PATCH 1/8] mm: implement cleancache
> config: loongarch-allmodconfig (https://download.01.org/0day-ci/archive/20251011/202510110501.92Srmvgx-lkp@intel.com/config)
> compiler: clang version 19.1.7 (https://github.com/llvm/llvm-project cd708029e0b2869e80abe31ddb175f7c35361f90)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251011/202510110501.92Srmvgx-lkp@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202510110501.92Srmvgx-lkp@intel.com/
>
> All errors (new ones prefixed by >>):
>
> >> mm/cleancache.c:119:13: error: casting from randomized structure pointer type 'struct address_space *' to 'struct cleancache_inode *'
>      119 |         *ccinode = (struct cleancache_inode *)folio->mapping;
>          |                    ^
>    1 error generated.

Matthew's suggestion to use unions for members with multiple uses will
remove the need for typecasting and should solve this issue.

>
>
> vim +119 mm/cleancache.c
>
>    113
>    114  static void folio_attachment(struct folio *folio, struct cleancache_inode **ccinode,
>    115                               unsigned long *offset)
>    116  {
>    117          lockdep_assert_held(&(folio_pool(folio)->lock));
>    118
>  > 119          *ccinode = (struct cleancache_inode *)folio->mapping;
>    120          *offset = folio->index;
>    121  }
>    122
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki