Hi Christoph, I love your patch! Yet something to improve: [auto build test ERROR on axboe-block/for-next] [also build test ERROR on linus/master v5.15-rc2 next-20210920] [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/Christoph-Hellwig/nvdimm-pmem-fix-creating-the-dax-group/20210920-162804 base: https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git for-next config: riscv-buildonly-randconfig-r006-20210920 (attached as .config) compiler: riscv64-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/0day-ci/linux/commit/1a16d0f32f70bcd159a9f8cf32794f4024e8711e git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Christoph-Hellwig/nvdimm-pmem-fix-creating-the-dax-group/20210920-162804 git checkout 1a16d0f32f70bcd159a9f8cf32794f4024e8711e # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=riscv If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All errors (new ones prefixed by >>): drivers/dax/super.c:375:6: error: no previous prototype for 'run_dax' [-Werror=missing-prototypes] 375 | void run_dax(struct dax_device *dax_dev) | ^~~~~~~ >> drivers/dax/super.c:70:27: error: 'dax_get_by_host' defined but not used [-Werror=unused-function] 70 | static struct dax_device *dax_get_by_host(const char *host) | ^~~~~~~~~~~~~~~ cc1: all warnings being treated as errors vim +/dax_get_by_host +70 drivers/dax/super.c 1b7646014e0d838b Christoph Hellwig 2021-08-26 65 1b7646014e0d838b Christoph Hellwig 2021-08-26 66 /** 1b7646014e0d838b Christoph Hellwig 2021-08-26 67 * dax_get_by_host() - temporary lookup mechanism for filesystem-dax 1b7646014e0d838b Christoph Hellwig 2021-08-26 68 * @host: alternate name for the device registered by a dax driver 1b7646014e0d838b Christoph Hellwig 2021-08-26 69 */ 1b7646014e0d838b Christoph Hellwig 2021-08-26 @70 static struct dax_device *dax_get_by_host(const char *host) 1b7646014e0d838b Christoph Hellwig 2021-08-26 71 { 1b7646014e0d838b Christoph Hellwig 2021-08-26 72 struct dax_device *dax_dev, *found = NULL; 1b7646014e0d838b Christoph Hellwig 2021-08-26 73 int hash, id; 1b7646014e0d838b Christoph Hellwig 2021-08-26 74 1b7646014e0d838b Christoph Hellwig 2021-08-26 75 if (!host) 1b7646014e0d838b Christoph Hellwig 2021-08-26 76 return NULL; 1b7646014e0d838b Christoph Hellwig 2021-08-26 77 1b7646014e0d838b Christoph Hellwig 2021-08-26 78 hash = dax_host_hash(host); 1b7646014e0d838b Christoph Hellwig 2021-08-26 79 1b7646014e0d838b Christoph Hellwig 2021-08-26 80 id = dax_read_lock(); 1b7646014e0d838b Christoph Hellwig 2021-08-26 81 spin_lock(&dax_host_lock); 1b7646014e0d838b Christoph Hellwig 2021-08-26 82 hlist_for_each_entry(dax_dev, &dax_host_list[hash], list) { 1b7646014e0d838b Christoph Hellwig 2021-08-26 83 if (!dax_alive(dax_dev) 1b7646014e0d838b Christoph Hellwig 2021-08-26 84 || strcmp(host, dax_dev->host) != 0) 1b7646014e0d838b Christoph Hellwig 2021-08-26 85 continue; 1b7646014e0d838b Christoph Hellwig 2021-08-26 86 1b7646014e0d838b Christoph Hellwig 2021-08-26 87 if (igrab(&dax_dev->inode)) 1b7646014e0d838b Christoph Hellwig 2021-08-26 88 found = dax_dev; 1b7646014e0d838b Christoph Hellwig 2021-08-26 89 break; 1b7646014e0d838b Christoph Hellwig 2021-08-26 90 } 1b7646014e0d838b Christoph Hellwig 2021-08-26 91 spin_unlock(&dax_host_lock); 1b7646014e0d838b Christoph Hellwig 2021-08-26 92 dax_read_unlock(id); 1b7646014e0d838b Christoph Hellwig 2021-08-26 93 1b7646014e0d838b Christoph Hellwig 2021-08-26 94 return found; 1b7646014e0d838b Christoph Hellwig 2021-08-26 95 } 1b7646014e0d838b Christoph Hellwig 2021-08-26 96 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org