[kbuild-all] drivers/md/raid10.c:995 wait_barrier() warn: if();

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: d6d09a6942050f21b065a134169002b4d6b701ef commit: fe630de009d0729584d79c78f43121e07c745fdc md/raid10: avoid deadlock on recovery. date: 1 year, 1 month ago config: nds32-randconfig-m031-20210818 (attached as .config) compiler: nds32le-linux-gcc (GCC) 11.2.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; New smatch warnings: drivers/md/raid10.c:995 wait_barrier() warn: if(); drivers/md/raid10.c:995 wait_barrier() warn: if(); drivers/md/raid10.c:995 wait_barrier() warn: ignoring unreachable code. Old smatch warnings: drivers/md/raid10.c:3220 raid10_sync_request() error: we previously assumed 'bio' could be null (see line 3212) drivers/md/raid10.c:3225 raid10_sync_request() error: we previously assumed 'mreplace' could be null (see line 3111) drivers/md/raid10.c:3575 calc_sectors() warn: should '1 << conf->geo.chunk_shift' be a 64 bit type? vim +995 drivers/md/raid10.c 0a27ec96b6fb1a NeilBrown 2006-01-06 978 e879a8793f915a NeilBrown 2011-10-11 979 static void wait_barrier(struct r10conf *conf) 0a27ec96b6fb1a NeilBrown 2006-01-06 980 { 0a27ec96b6fb1a NeilBrown 2006-01-06 981 spin_lock_irq(&conf->resync_lock); 0a27ec96b6fb1a NeilBrown 2006-01-06 982 if (conf->barrier) { fe630de009d072 Vitaly Mayatskikh 2020-03-03 983 struct bio_list *bio_list = current->bio_list; 0a27ec96b6fb1a NeilBrown 2006-01-06 984 conf->nr_waiting++; d6b42dcb995e6a NeilBrown 2012-03-19 985 /* Wait for the barrier to drop. d6b42dcb995e6a NeilBrown 2012-03-19 986 * However if there are already pending d6b42dcb995e6a NeilBrown 2012-03-19 987 * requests (preventing the barrier from d6b42dcb995e6a NeilBrown 2012-03-19 988 * rising completely), and the d6b42dcb995e6a NeilBrown 2012-03-19 989 * pre-process bio queue isn't empty, d6b42dcb995e6a NeilBrown 2012-03-19 990 * then don't wait, as we need to empty d6b42dcb995e6a NeilBrown 2012-03-19 991 * that queue to get the nr_pending d6b42dcb995e6a NeilBrown 2012-03-19 992 * count down. d6b42dcb995e6a NeilBrown 2012-03-19 993 */ 578b54ade8a5e0 NeilBrown 2016-11-14 994 raid10_log(conf->mddev, "wait barrier"); d6b42dcb995e6a NeilBrown 2012-03-19 @995 wait_event_lock_irq(conf->wait_barrier, d6b42dcb995e6a NeilBrown 2012-03-19 996 !conf->barrier || 0e5313e2d4ef93 Tomasz Majchrzak 2016-06-24 997 (atomic_read(&conf->nr_pending) && fe630de009d072 Vitaly Mayatskikh 2020-03-03 998 bio_list && fe630de009d072 Vitaly Mayatskikh 2020-03-03 999 (!bio_list_empty(&bio_list[0]) || fe630de009d072 Vitaly Mayatskikh 2020-03-03 1000 !bio_list_empty(&bio_list[1]))) || fe630de009d072 Vitaly Mayatskikh 2020-03-03 1001 /* move on if recovery thread is fe630de009d072 Vitaly Mayatskikh 2020-03-03 1002 * blocked by us fe630de009d072 Vitaly Mayatskikh 2020-03-03 1003 */ fe630de009d072 Vitaly Mayatskikh 2020-03-03 1004 (conf->mddev->thread->tsk == current && fe630de009d072 Vitaly Mayatskikh 2020-03-03 1005 test_bit(MD_RECOVERY_RUNNING, fe630de009d072 Vitaly Mayatskikh 2020-03-03 1006 &conf->mddev->recovery) && fe630de009d072 Vitaly Mayatskikh 2020-03-03 1007 conf->nr_queued > 0), eed8c02e680c04 Lukas Czerner 2012-11-30 1008 conf->resync_lock); 0a27ec96b6fb1a NeilBrown 2006-01-06 1009 conf->nr_waiting--; 0e5313e2d4ef93 Tomasz Majchrzak 2016-06-24 1010 if (!conf->nr_waiting) 0e5313e2d4ef93 Tomasz Majchrzak 2016-06-24 1011 wake_up(&conf->wait_barrier); 0a27ec96b6fb1a NeilBrown 2006-01-06 1012 } 0e5313e2d4ef93 Tomasz Majchrzak 2016-06-24 1013 atomic_inc(&conf->nr_pending); ^1da177e4c3f41 Linus Torvalds 2005-04-16 1014 spin_unlock_irq(&conf->resync_lock); ^1da177e4c3f41 Linus Torvalds 2005-04-16 1015 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 1016 :::::: The code at line 995 was first introduced by commit :::::: d6b42dcb995e6acd7cc276774e751ffc9f0ef4bf md/raid1,raid10: avoid deadlock during resync/recovery. :::::: TO: NeilBrown <neilb(a)suse.de&gt; :::::: CC: NeilBrown <neilb(a)suse.de&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org