Hi Christian, I love your patch! Perhaps something to improve: [auto build test WARNING on 3cea11cd5e3b00d91caf0b4730194039b45c5891] url: https://github.com/0day-ci/linux/commits/Christian-Brauner/fs-idmapped-mo... base: 3cea11cd5e3b00d91caf0b4730194039b45c5891 config: powerpc-allyesconfig (attached as .config) compiler: powerpc64-linux-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/be817fb36176ab0c272188d583293ba16... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Christian-Brauner/fs-idmapped-mounts/20201115-185706 git checkout be817fb36176ab0c272188d583293ba16fd84cca # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): drivers/android/binderfs.c: In function 'binderfs_rename': drivers/android/binderfs.c:367:23: error: passing argument 1 of 'simple_rename' from incompatible pointer type [-Werror=incompatible-pointer-types] 367 | return simple_rename(old_dir, old_dentry, new_dir, new_dentry, flags); | ^~~~~~~ | | | struct inode * In file included from drivers/android/binderfs.c:5: include/linux/fs.h:3203:26: note: expected 'struct user_namespace *' but argument is of type 'struct inode *' 3203 | extern int simple_rename(struct user_namespace *, struct inode *, | ^~~~~~~~~~~~~~~~~~~~~~~ drivers/android/binderfs.c:367:32: error: passing argument 2 of 'simple_rename' from incompatible pointer type [-Werror=incompatible-pointer-types] 367 | return simple_rename(old_dir, old_dentry, new_dir, new_dentry, flags); | ^~~~~~~~~~ | | | struct dentry * In file included from drivers/android/binderfs.c:5: include/linux/fs.h:3203:51: note: expected 'struct inode *' but argument is of type 'struct dentry *' 3203 | extern int simple_rename(struct user_namespace *, struct inode *, | ^~~~~~~~~~~~~~ drivers/android/binderfs.c:367:44: error: passing argument 3 of 'simple_rename' from incompatible pointer type [-Werror=incompatible-pointer-types] 367 | return simple_rename(old_dir, old_dentry, new_dir, new_dentry, flags); | ^~~~~~~ | | | struct inode * In file included from drivers/android/binderfs.c:5: include/linux/fs.h:3204:5: note: expected 'struct dentry *' but argument is of type 'struct inode *' 3204 | struct dentry *, struct inode *, struct dentry *, | ^~~~~~~~~~~~~~~ drivers/android/binderfs.c:367:53: error: passing argument 4 of 'simple_rename' from incompatible pointer type [-Werror=incompatible-pointer-types] 367 | return simple_rename(old_dir, old_dentry, new_dir, new_dentry, flags); | ^~~~~~~~~~ | | | struct dentry * In file included from drivers/android/binderfs.c:5: include/linux/fs.h:3204:22: note: expected 'struct inode *' but argument is of type 'struct dentry *' 3204 | struct dentry *, struct inode *, struct dentry *, | ^~~~~~~~~~~~~~ 367 | return simple_rename(old_dir, old_dentry, new_dir, new_dentry, flags); | ^~~~~ | | | unsigned int In file included from drivers/android/binderfs.c:5: include/linux/fs.h:3204:38: note: expected 'struct dentry *' but argument is of type 'unsigned int' 3204 | struct dentry *, struct inode *, struct dentry *, | ^~~~~~~~~~~~~~~ drivers/android/binderfs.c:367:9: error: too few arguments to function 'simple_rename' 367 | return simple_rename(old_dir, old_dentry, new_dir, new_dentry, flags); | ^~~~~~~~~~~~~ In file included from drivers/android/binderfs.c:5: include/linux/fs.h:3203:12: note: declared here 3203 | extern int simple_rename(struct user_namespace *, struct inode *, | ^~~~~~~~~~~~~ drivers/android/binderfs.c:368:1: error: control reaches end of non-void function [-Werror=return-type] 368 | } | ^ cc1: some warnings being treated as errors vim +/simple_rename +367 drivers/android/binderfs.c e98e6fa18636609 Christian Brauner 2019-01-21 357 be817fb36176ab0 Christian Brauner 2020-11-15 358 static int binderfs_rename(struct user_namespace *user_ns, be817fb36176ab0 Christian Brauner 2020-11-15 359 struct inode *old_dir, struct dentry *old_dentry, 3ad20fe393b3102 Christian Brauner 2018-12-14 360 struct inode *new_dir, struct dentry *new_dentry, 3ad20fe393b3102 Christian Brauner 2018-12-14 361 unsigned int flags) 3ad20fe393b3102 Christian Brauner 2018-12-14 362 { e98e6fa18636609 Christian Brauner 2019-01-21 363 if (is_binderfs_control_device(old_dentry) || e98e6fa18636609 Christian Brauner 2019-01-21 364 is_binderfs_control_device(new_dentry)) 3ad20fe393b3102 Christian Brauner 2018-12-14 365 return -EPERM; 3ad20fe393b3102 Christian Brauner 2018-12-14 366 e98e6fa18636609 Christian Brauner 2019-01-21 @367 return simple_rename(old_dir, old_dentry, new_dir, new_dentry, flags); 3ad20fe393b3102 Christian Brauner 2018-12-14 368 } 3ad20fe393b3102 Christian Brauner 2018-12-14 369 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org