Re: [PATCH 05/18] MM: reclaim mustn't enter FS for SWP_FS_OPS swap-space

[kernel test robot <lkp@intel.com>]

Hi NeilBrown,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on cifs/for-next]
[also build test ERROR on axboe-block/for-next rostedt-trace/for-next linus/master v5.16-rc5]
[cannot apply to trondmy-nfs/linux-next hnaz-mm/master mszeredi-vfs/overlayfs-next next-20211216]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/NeilBrown/Repair-SWAP-over-NFS/20211217-075659
base:   git://git.samba.org/sfrench/cifs-2.6.git for-next
config: arm-randconfig-r006-20211216 (https://download.01.org/0day-ci/archive/20211217/202112171635.JUIRMzHQ-lkp@intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 9043c3d65b11b442226015acfbf8167684586cfa)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        # https://github.com/0day-ci/linux/commit/a8e1b1ffec6ade1545df519d254eae0400b7ec37
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review NeilBrown/Repair-SWAP-over-NFS/20211217-075659
        git checkout a8e1b1ffec6ade1545df519d254eae0400b7ec37
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> mm/vmscan.c:1480:20: error: implicit declaration of function 'page_swap_info' [-Werror,-Wimplicit-function-declaration]
           return !data_race(page_swap_info(page)->flags & SWP_FS_OPS);
                             ^
   mm/vmscan.c:1480:20: note: did you mean 'swp_swap_info'?
   include/linux/swap.h:487:40: note: 'swp_swap_info' declared here
   static inline struct swap_info_struct *swp_swap_info(swp_entry_t entry)
                                          ^
>> mm/vmscan.c:1480:42: error: member reference type 'int' is not a pointer
           return !data_race(page_swap_info(page)->flags & SWP_FS_OPS);
                             ~~~~~~~~~~~~~~~~~~~~  ^
   include/linux/compiler.h:216:28: note: expanded from macro 'data_race'
           __unqual_scalar_typeof(({ expr; })) __v = ({                    \
                                     ^~~~
   include/linux/compiler_types.h:291:13: note: expanded from macro '__unqual_scalar_typeof'
                   _Generic((x),                                           \
                             ^
>> mm/vmscan.c:1480:20: error: implicit declaration of function 'page_swap_info' [-Werror,-Wimplicit-function-declaration]
           return !data_race(page_swap_info(page)->flags & SWP_FS_OPS);
                             ^
>> mm/vmscan.c:1480:42: error: member reference type 'int' is not a pointer
           return !data_race(page_swap_info(page)->flags & SWP_FS_OPS);
                             ~~~~~~~~~~~~~~~~~~~~  ^
   include/linux/compiler.h:216:28: note: expanded from macro 'data_race'
           __unqual_scalar_typeof(({ expr; })) __v = ({                    \
                                     ^~~~
   include/linux/compiler_types.h:298:15: note: expanded from macro '__unqual_scalar_typeof'
                            default: (x)))
                                      ^
>> mm/vmscan.c:1480:20: error: implicit declaration of function 'page_swap_info' [-Werror,-Wimplicit-function-declaration]
           return !data_race(page_swap_info(page)->flags & SWP_FS_OPS);
                             ^
>> mm/vmscan.c:1480:42: error: member reference type 'int' is not a pointer
           return !data_race(page_swap_info(page)->flags & SWP_FS_OPS);
                             ~~~~~~~~~~~~~~~~~~~~  ^
   include/linux/compiler.h:218:3: note: expanded from macro 'data_race'
                   expr;                                                   \
                   ^~~~
>> mm/vmscan.c:1480:9: error: invalid argument type 'void' to unary expression
           return !data_race(page_swap_info(page)->flags & SWP_FS_OPS);
                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   7 errors generated.


vim +/page_swap_info +1480 mm/vmscan.c

  1467	
  1468	static bool test_may_enter_fs(struct page *page, gfp_t gfp_mask)
  1469	{
  1470		if (gfp_mask & __GFP_FS)
  1471			return true;
  1472		if (!PageSwapCache(page) || !(gfp_mask & __GFP_IO))
  1473			return false;
  1474		/* We can "enter_fs" for swap-cache with only __GFP_IO
  1475		 * providing this isn't SWP_FS_OPS.
  1476		 * ->flags can be updated non-atomicially (scan_swap_map_slots),
  1477		 * but that will never affect SWP_FS_OPS, so the data_race
  1478		 * is safe.
  1479		 */
> 1480		return !data_race(page_swap_info(page)->flags & SWP_FS_OPS);
  1481	}
  1482	

---
0-DAY CI Kernel Test Service, Intel Corporation
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