Re: Re: [PATCH] dcache: add fs.dentry-limit sysctl with negative-first reaper

[Horst Birthelmer <horst@birthelmer.de>]

On Fri, May 15, 2026 at 11:09:54PM +0800, kernel test robot wrote:
> Hi Horst,
> 
> kernel test robot noticed the following build errors:
> 
> [auto build test ERROR on 5d6919055dec134de3c40167a490f33c74c12581]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Horst-Birthelmer/dcache-add-fs-dentry-limit-sysctl-with-negative-first-reaper/20260515-154600
> base:   5d6919055dec134de3c40167a490f33c74c12581
> patch link:    https://lore.kernel.org/r/20260514-limit-dentries-cache-v1-1-431b9eb0c530%40ddn.com
> patch subject: [PATCH] dcache: add fs.dentry-limit sysctl with negative-first reaper
> config: openrisc-randconfig-r073-20260515 (https://download.01.org/0day-ci/archive/20260515/202605152333.0pOd2zJR-lkp@intel.com/config)
> compiler: or1k-linux-gcc (GCC) 10.5.0
> smatch: v0.5.0-9185-gbcc58b9c
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260515/202605152333.0pOd2zJR-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/202605152333.0pOd2zJR-lkp@intel.com/
> 
> All errors (new ones prefixed by >>):
> 
>    fs/dcache.c: In function 'dentry_limit_worker_fn':
> >> fs/dcache.c:1474:7: error: implicit declaration of function 'get_nr_dentry'; did you mean 'retain_dentry'? [-Werror=implicit-function-declaration]
>     1474 |  nr = get_nr_dentry();
>          |       ^~~~~~~~~~~~~
>          |       retain_dentry
>    cc1: some warnings being treated as errors
> 
> 
> vim +1474 fs/dcache.c
> 
...
> 
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki

This is puzzling to me get_nr_dentry() is defined in line 178 in the same file and first used in line 209 
and has been there since 2013.

Builds fine applied to tag v7.1-rc3 and to the current master with gcc and clang.