Hi Olga, Thank you for the patch! Yet something to improve: [auto build test ERROR on nfs/linux-next] [also build test ERROR on pcmoore-selinux/next linus/master security/next-testing v5.11-rc7 next-20210211] [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/Olga-Kornievskaia/Add-new-hook-to-compare-new-mount-to-an-existing-mount/20210213-052321 base: git://git.linux-nfs.org/projects/trondmy/linux-nfs.git linux-next config: arm-defconfig (attached as .config) compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0 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/0day-ci/linux/commit/ff69e0bcc99716695e11ed2741b2e01d6014f960 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Olga-Kornievskaia/Add-new-hook-to-compare-new-mount-to-an-existing-mount/20210213-052321 git checkout ff69e0bcc99716695e11ed2741b2e01d6014f960 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All errors (new ones prefixed by >>): fs/nfs/super.c: In function 'nfs_compare_super': >> fs/nfs/super.c:1179:5: error: implicit declaration of function 'security_sb_do_mnt_opts_match'; did you mean 'security_sb_set_mnt_opts'? [-Werror=implicit-function-declaration] 1179 | !security_sb_do_mnt_opts_match(sb, fc->security)) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | security_sb_set_mnt_opts cc1: some warnings being treated as errors vim +1179 fs/nfs/super.c 1164 1165 static int nfs_compare_super(struct super_block *sb, struct fs_context *fc) 1166 { 1167 struct nfs_server *server = fc->s_fs_info, *old = NFS_SB(sb); 1168 1169 if (!nfs_compare_super_address(old, server)) 1170 return 0; 1171 /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */ 1172 if (old->flags & NFS_MOUNT_UNSHARED) 1173 return 0; 1174 if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0) 1175 return 0; 1176 if (!nfs_compare_userns(old, server)) 1177 return 0; 1178 if ((old->has_sec_mnt_opts || fc->security) && > 1179 !security_sb_do_mnt_opts_match(sb, fc->security)) 1180 return 0; 1181 return nfs_compare_mount_options(sb, server, fc); 1182 } 1183 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org