Hi Chao,

I love your patch! Yet something to improve:

[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on linus/master v6.2-rc3 next-20230111]
[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#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Chao-Yu/proc-introduce-proc_statfs/20230110-232155
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20230110152003.1118777-1-chao%40kernel.org
patch subject: [PATCH] proc: introduce proc_statfs()
config: x86_64-randconfig-a001
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
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
        # https://github.com/intel-lab-lkp/linux/commit/ce43513d85fa0d0988f4c4cae86b5181ae9266a2
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Chao-Yu/proc-introduce-proc_statfs/20230110-232155
        git checkout ce43513d85fa0d0988f4c4cae86b5181ae9266a2
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash fs/

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

All errors (new ones prefixed by >>):

>> fs/proc/inode.c:184:19: error: use of undeclared identifier 'PROC_NAME_LEN'
           buf->f_namelen = PROC_NAME_LEN;
                            ^
   1 error generated.


vim +/PROC_NAME_LEN +184 fs/proc/inode.c

   179	
   180	static int proc_statfs(struct dentry *dentry, struct kstatfs *buf)
   181	{
   182		buf->f_type = dentry->d_sb->s_magic;
   183		buf->f_bsize = dentry->d_sb->s_blocksize;
 > 184		buf->f_namelen = PROC_NAME_LEN;
   185		return 0;
   186	}
   187	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests