Hi Hans, I love your patch! Perhaps something to improve: [auto build test WARNING on linus/master] [cannot apply to v5.4-rc2 next-20191011] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to specify the base tree in git format-patch, please see https://stackoverflow.com/a/37406982] url: https://github.com/0day-ci/linux/commits/Hans-de-Goede/fs-Add-VirtualBox-guest-shared-folder-vboxsf-support/20191004-022414 reproduce: # apt-get install sparse # sparse version: v0.6.1-rc1-43-g0ccb3b4-dirty make ARCH=x86_64 allmodconfig make C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' If you fix the issue, kindly add following tag Reported-by: kbuild test robot <lkp@xxxxxxxxx> sparse warnings: (new ones prefixed by >>) >> fs/vboxsf/super.c:382:5: sparse: sparse: symbol 'vboxsf_parse_monolithic' was not declared. Should it be static? Please review and possibly fold the followup patch. --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation