[PATCH] erofs: make filesystem exportable

[kernel test robot]

Hi Hongnan,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on xiang-erofs/dev-test]
[also build test WARNING on v5.18-rc3 next-20220422]
[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/intel-lab-lkp/linux/commits/Hongnan-Li/erofs-make-filesystem-exportable/20220424-211653
base:   https://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git dev-test
config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20220424/202204242223.Hf6HESVt-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 11.2.0
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/c0fc15c5ccc4a5090cc32744ba63bde8ea558ac7
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Hongnan-Li/erofs-make-filesystem-exportable/20220424-211653
        git checkout c0fc15c5ccc4a5090cc32744ba63bde8ea558ac7
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash fs/

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

All warnings (new ones prefixed by >>):

>> fs/erofs/super.c:601:16: warning: no previous prototype for 'erofs_get_parent' [-Wmissing-prototypes]
     601 | struct dentry *erofs_get_parent(struct dentry *child)
         |                ^~~~~~~~~~~~~~~~


vim +/erofs_get_parent +601 fs/erofs/super.c

   600	
 > 601	struct dentry *erofs_get_parent(struct dentry *child)
   602	{
   603		erofs_nid_t nid;
   604		unsigned int d_type;
   605		int err;
   606	
   607		err = erofs_namei(d_inode(child), &dotdot_name, &nid, &d_type);
   608		if (err)
   609			return ERR_PTR(err);
   610		return d_obtain_alias(erofs_iget(child->d_sb, nid, d_type == FT_DIR));
   611	}
   612	

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp