Hi sishuaigong, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on hch-configfs/for-next] [also build test WARNING on v5.14-rc7 next-20210823] [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/sishuaigong/configfs-fix-a-race-... base: git://git.infradead.org/users/hch/configfs.git for-next config: m68k-buildonly-randconfig-r006-20210822 (attached as .config) compiler: m68k-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/ff28c41926fb184655325e34dba02c438... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review sishuaigong/configfs-fix-a-race-in-configfs_lookup/20210824-034517 git checkout ff28c41926fb184655325e34dba02c438963dcf5 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=m68k 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 >>): fs/configfs/dir.c: In function 'configfs_lookup': 446 | struct configfs_attribute *attr = sd->s_element; | ^~~~~~ vim +446 fs/configfs/dir.c 419 420 static struct dentry * configfs_lookup(struct inode *dir, 421 struct dentry *dentry, 422 unsigned int flags) 423 { 424 struct configfs_dirent * parent_sd = dentry->d_parent->d_fsdata; 425 struct configfs_dirent * sd; 426 struct inode *inode = NULL; 427 428 /* 429 * Fake invisibility if dir belongs to a group/default groups hierarchy 430 * being attached 431 * 432 * This forbids userspace to read/write attributes of items which may 433 * not complete their initialization, since the dentries of the 434 * attributes won't be instantiated. 435 */ 436 if (!configfs_dirent_is_ready(parent_sd)) 437 return ERR_PTR(-ENOENT); 438 439 spin_lock(&configfs_dirent_lock); 440 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { 441 if (sd->s_type & CONFIGFS_NOT_PINNED) { 442 const unsigned char *name = configfs_get_name(sd); 443 if (strcmp(name, dentry->d_name.name)) 444 continue; 445 447 umode_t mode = (attr->ca_mode & S_IALLUGO) | S_IFREG; 448 449 dentry->d_fsdata = configfs_get(sd); 450 sd->s_dentry = dentry; 451 452 spin_unlock(&configfs_dirent_lock); 453 454 inode = configfs_create(dentry, mode); 455 if (IS_ERR(inode)) { 456 configfs_put(sd); 457 return ERR_CAST(inode); 458 } 459 if (sd->s_type & CONFIGFS_ITEM_BIN_ATTR) { 460 inode->i_size = 0; 461 inode->i_fop = &configfs_bin_file_operations; 462 } else { 463 inode->i_size = PAGE_SIZE; 464 inode->i_fop = &configfs_file_operations; 465 } 466 goto out; 467 } 468 } 469 spin_unlock(&configfs_dirent_lock); 470 471 /* 472 * If it doesn't exist and it isn't a NOT_PINNED item, 473 * it must be negative. 474 */ 475 if (dentry->d_name.len > NAME_MAX) 476 return ERR_PTR(-ENAMETOOLONG); 477 out: 478 d_add(dentry, inode); 479 return NULL; 480 } 481 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org