tree: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git fscache-iter head: f6ac6a6db767d26c3330f0cecadd4f331ee6d291 commit: 02956137643245200e02a2683c203fed2308aece [40/55] fscache: Add read helper config: x86_64-randconfig-a013-20200909 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 0a5dc7effb191eff740e0e7ae7bd8e1f6bdb3ad9) 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 # install x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu git checkout 02956137643245200e02a2683c203fed2308aece # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 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 >>): void fscache_rreq_write_to_cache(struct fscache_read_request *rreq) ^ fs/fscache/read_helper.c:202:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void fscache_rreq_write_to_cache(struct fscache_read_request *rreq) ^ static 1 warning generated. # https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/com... git remote add dhowells-fs https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git git fetch --no-tags dhowells-fs fscache-iter git checkout 02956137643245200e02a2683c203fed2308aece vim +/fscache_rreq_write_to_cache +202 fs/fscache/read_helper.c 197 198 /* 199 * Perform any outstanding writes to the cache. We inherit a ref from the 200 * caller. 201 */ 203 { 204 struct fscache_io_request *ioreq, *next, *p; 205 struct iov_iter iter; 206 207 fscache_wait_for_object(rreq->cookie, rreq->object, FSCACHE_WANT_WRITE); 208 209 /* We don't want terminating writes trying to wake us up whilst we're 210 * still going through the list. 211 */ 212 atomic_inc(&rreq->nr_io_ops); 213 214 list_for_each_entry_safe(ioreq, p, &rreq->io_requests, rreq_link) { 215 if (!test_bit(FSCACHE_IO_WRITE_TO_CACHE, &ioreq->flags)) { 216 list_del_init(&ioreq->rreq_link); 217 fscache_put_io_request(ioreq); 218 } 219 } 220 221 list_for_each_entry(ioreq, &rreq->io_requests, rreq_link) { 222 /* Amalgamate adjacent writes */ 223 while (!list_is_last(&ioreq->rreq_link, &rreq->io_requests)) { 224 next = list_next_entry(ioreq, rreq_link); 225 if (next->start > ioreq->start + ioreq->len) 226 break; 227 ioreq->len += next->len; 228 list_del_init(&next->rreq_link); 229 fscache_put_io_request(next); 230 } 231 232 iov_iter_xarray(&iter, WRITE, &rreq->mapping->i_pages, 233 ioreq->start, ioreq->len); 234 235 ioreq->io_done = fscache_rreq_copy_done; 236 fscache_get_io_request(ioreq); 237 rreq->object->cache->ops->write(rreq->object, ioreq, &iter); 238 } 239 240 /* If we decrement nr_io_ops to 0, the usage ref belongs to us. */ 241 if (atomic_dec_and_test(&rreq->nr_io_ops)) 242 fscache_rreq_unmark_after_write(rreq); 243 } 244 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org