tree: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git netfs-folio-regions head: 215a4ee495a95cc73256ed76f91cb78bcabd6b8e commit: 27ed0ce3a75fcb90e4c016da19682b7fb275ccaf [14/28] netfs: Initiate write request from a dirty region config: hexagon-randconfig-r041-20210818 (attached as .config) compiler: clang version 12.0.0 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://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 netfs-folio-regions git checkout 27ed0ce3a75fcb90e4c016da19682b7fb275ccaf # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=hexagon 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 >>): if (!folio_trylock(folio)) ^~~~~~~~~~~~~~~~~~~~~ fs/netfs/write_back.c:107:9: note: uninitialized use occurs here return ret; ^~~ fs/netfs/write_back.c:103:3: note: remove the 'if' if its condition is always true if (!folio_trylock(folio)) ^~~~~~~~~~~~~~~~~~~~~~~~~~ fs/netfs/write_back.c:90:9: note: initialize the variable 'ret' to silence this warning int ret; ^ = 0 1 warning generated. vim +103 fs/netfs/write_back.c 84 85 static int netfs_lock_folios_iterator(struct xa_state *xas, 86 struct folio *folio, 87 struct netfs_write_request *wreq, 88 struct writeback_control *wbc) 89 { 90 int ret; 91 92 /* At this point we hold neither the i_pages lock nor the 93 * folio lock: the folio may be truncated or invalidated 94 * (changing folio->mapping to NULL), or even swizzled 95 * back from swapper_space to tmpfs file mapping 96 */ 97 if (wbc->sync_mode != WB_SYNC_NONE) { 98 xas_pause(xas); 99 rcu_read_unlock(); 100 ret = folio_lock_killable(folio); 101 rcu_read_lock(); 102 } else { 104 ret = -EBUSY; 105 } 106 107 return ret; 108 } 109 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org