Re: [PATCH v2 5/5] fs: allow to mount beneath top mount

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

Hi Christian,

I love your patch! Perhaps something to improve:

[auto build test WARNING on 197b6b60ae7bc51dd0814953c562833143b292aa]

url:    https://github.com/intel-lab-lkp/linux/commits/Christian-Brauner/fs-add-path_mounted/20230329-001618
base:   197b6b60ae7bc51dd0814953c562833143b292aa
patch link:    https://lore.kernel.org/r/20230202-fs-move-mount-replace-v2-5-f53cd31d6392%40kernel.org
patch subject: [PATCH v2 5/5] fs: allow to mount beneath top mount
config: x86_64-randconfig-a014-20230327 (https://download.01.org/0day-ci/archive/20230329/202303290629.d046fvuG-lkp@intel.com/config)
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/13451428e46188ad86767587daa736968e4cc62c
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Christian-Brauner/fs-add-path_mounted/20230329-001618
        git checkout 13451428e46188ad86767587daa736968e4cc62c
        # 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

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202303290629.d046fvuG-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> fs/namespace.c:990: warning: expecting prototype for mnt_beneath(). Prototype was for attach_mnt_beneath() instead


vim +990 fs/namespace.c

   969	
   970	/**
   971	 * mnt_beneath - mount a mount beneath another one, attach to
   972	 *               @mount_hashtable and parent's list of child mounts
   973	 *
   974	 * @new_parent: the source mount
   975	 * @top_mnt:	the mount beneath which @new_parent is mounted
   976	 * @new_mp:	the new mountpoint of @top_mnt on @new_parent
   977	 *
   978	 * Remove @top_mnt from its current parent and mountpoint and mount it
   979	 * on @new_mp on @new_parent, and mount @new_parent on the old parent
   980	 * and old mountpoint of @top_mnt. Finally, attach @new_parent mount to
   981	 * @mnt_hashtable and @new_parent->mnt_parent->mnt_mounts.
   982	 *
   983	 * Note, when we call __attach_mnt() we've already mounted @new_parent
   984	 * on top of @top_mnt's old parent so @new_parent->mnt_parent will point
   985	 * to the correct parent.
   986	 */
   987	static void attach_mnt_beneath(struct mount *new_parent,
   988			     struct mount *top_mnt,
   989			     struct mountpoint *new_mp)
 > 990	{
   991		mnt_set_mountpoint_beneath(new_parent, top_mnt, new_mp);
   992		__attach_mnt(new_parent, new_parent->mnt_parent);
   993	}
   994	

-- 
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https://github.com/intel/lkp-tests