Hi Li, kernel test robot noticed the following build warnings: [auto build test WARNING on next-20240823] url: https://github.com/intel-lab-lkp/linux/commits/Li-Zetao/ext4-Use-scoped-scoped_guard-to-drop-read_lock-unlock-pair/20240826-123331 base: next-20240823 patch link: https://lore.kernel.org/r/20240823061824.3323522-4-lizetao1%40huawei.com patch subject: [PATCH -next 3/3] ext4: Use scoped()/scoped_guard() to drop rcu_read_lock()/unlock pair config: s390-allmodconfig (https://download.01.org/0day-ci/archive/20240829/202408290407.XQuWf1oH-lkp@xxxxxxxxx/config) compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project 08e5a1de8227512d4774a534b91cb2353cef6284) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240829/202408290407.XQuWf1oH-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202408290407.XQuWf1oH-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): In file included from fs/ext4/mballoc.c:12: In file included from fs/ext4/ext4_jbd2.h:16: In file included from include/linux/jbd2.h:23: In file included from include/linux/buffer_head.h:12: In file included from include/linux/blk_types.h:10: In file included from include/linux/bvec.h:10: In file included from include/linux/highmem.h:10: In file included from include/linux/mm.h:2202: include/linux/vmstat.h:504:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion] 504 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS + | ~~~~~~~~~~~~~~~~~~~~~ ^ 505 | item]; | ~~~~ include/linux/vmstat.h:511:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion] 511 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS + | ~~~~~~~~~~~~~~~~~~~~~ ^ 512 | NR_VM_NUMA_EVENT_ITEMS + | ~~~~~~~~~~~~~~~~~~~~~~ include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion] 518 | return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_" | ~~~~~~~~~~~ ^ ~~~ include/linux/vmstat.h:524:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion] 524 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS + | ~~~~~~~~~~~~~~~~~~~~~ ^ 525 | NR_VM_NUMA_EVENT_ITEMS + | ~~~~~~~~~~~~~~~~~~~~~~ >> fs/ext4/mballoc.c:3470:2: warning: label followed by a declaration is a C23 extension [-Wc23-extensions] 3470 | guard(rcu)(); | ^ include/linux/cleanup.h:303:2: note: expanded from macro 'guard' 303 | CLASS(_name, __UNIQUE_ID(guard)) | ^ include/linux/cleanup.h:258:2: note: expanded from macro 'CLASS' 258 | class_##_name##_t var __cleanup(class_##_name##_destructor) = \ | ^ <scratch space>:94:1: note: expanded from here 94 | class_rcu_t | ^ 5 warnings generated. Kconfig warnings: (for reference only) WARNING: unmet direct dependencies detected for OMAP2PLUS_MBOX Depends on [n]: MAILBOX [=y] && (ARCH_OMAP2PLUS || ARCH_K3) Selected by [m]: - TI_K3_M4_REMOTEPROC [=m] && REMOTEPROC [=y] && (ARCH_K3 || COMPILE_TEST [=y]) vim +3470 fs/ext4/mballoc.c 3386 3387 static int ext4_mb_init_backend(struct super_block *sb) 3388 { 3389 ext4_group_t ngroups = ext4_get_groups_count(sb); 3390 ext4_group_t i; 3391 struct ext4_sb_info *sbi = EXT4_SB(sb); 3392 int err; 3393 struct ext4_group_desc *desc; 3394 struct ext4_group_info ***group_info; 3395 struct kmem_cache *cachep; 3396 3397 err = ext4_mb_alloc_groupinfo(sb, ngroups); 3398 if (err) 3399 return err; 3400 3401 sbi->s_buddy_cache = new_inode(sb); 3402 if (sbi->s_buddy_cache == NULL) { 3403 ext4_msg(sb, KERN_ERR, "can't get new inode"); 3404 goto err_freesgi; 3405 } 3406 /* To avoid potentially colliding with an valid on-disk inode number, 3407 * use EXT4_BAD_INO for the buddy cache inode number. This inode is 3408 * not in the inode hash, so it should never be found by iget(), but 3409 * this will avoid confusion if it ever shows up during debugging. */ 3410 sbi->s_buddy_cache->i_ino = EXT4_BAD_INO; 3411 EXT4_I(sbi->s_buddy_cache)->i_disksize = 0; 3412 for (i = 0; i < ngroups; i++) { 3413 cond_resched(); 3414 desc = ext4_get_group_desc(sb, i, NULL); 3415 if (desc == NULL) { 3416 ext4_msg(sb, KERN_ERR, "can't read descriptor %u", i); 3417 goto err_freebuddy; 3418 } 3419 if (ext4_mb_add_groupinfo(sb, i, desc) != 0) 3420 goto err_freebuddy; 3421 } 3422 3423 if (ext4_has_feature_flex_bg(sb)) { 3424 /* a single flex group is supposed to be read by a single IO. 3425 * 2 ^ s_log_groups_per_flex != UINT_MAX as s_mb_prefetch is 3426 * unsigned integer, so the maximum shift is 32. 3427 */ 3428 if (sbi->s_es->s_log_groups_per_flex >= 32) { 3429 ext4_msg(sb, KERN_ERR, "too many log groups per flexible block group"); 3430 goto err_freebuddy; 3431 } 3432 sbi->s_mb_prefetch = min_t(uint, 1 << sbi->s_es->s_log_groups_per_flex, 3433 BLK_MAX_SEGMENT_SIZE >> (sb->s_blocksize_bits - 9)); 3434 sbi->s_mb_prefetch *= 8; /* 8 prefetch IOs in flight at most */ 3435 } else { 3436 sbi->s_mb_prefetch = 32; 3437 } 3438 if (sbi->s_mb_prefetch > ext4_get_groups_count(sb)) 3439 sbi->s_mb_prefetch = ext4_get_groups_count(sb); 3440 /* 3441 * now many real IOs to prefetch within a single allocation at 3442 * CR_POWER2_ALIGNED. Given CR_POWER2_ALIGNED is an CPU-related 3443 * optimization we shouldn't try to load too many groups, at some point 3444 * we should start to use what we've got in memory. 3445 * with an average random access time 5ms, it'd take a second to get 3446 * 200 groups (* N with flex_bg), so let's make this limit 4 3447 */ 3448 sbi->s_mb_prefetch_limit = sbi->s_mb_prefetch * 4; 3449 if (sbi->s_mb_prefetch_limit > ext4_get_groups_count(sb)) 3450 sbi->s_mb_prefetch_limit = ext4_get_groups_count(sb); 3451 3452 return 0; 3453 3454 err_freebuddy: 3455 cachep = get_groupinfo_cache(sb->s_blocksize_bits); 3456 while (i-- > 0) { 3457 struct ext4_group_info *grp = ext4_get_group_info(sb, i); 3458 3459 if (grp) 3460 kmem_cache_free(cachep, grp); 3461 } 3462 i = sbi->s_group_info_size; 3463 scoped_guard(rcu) { 3464 group_info = rcu_dereference(sbi->s_group_info); 3465 while (i-- > 0) 3466 kfree(group_info[i]); 3467 } 3468 iput(sbi->s_buddy_cache); 3469 err_freesgi: > 3470 guard(rcu)(); 3471 kvfree(rcu_dereference(sbi->s_group_info)); 3472 return -ENOMEM; 3473 } 3474 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
