On Tue, 14 Jan 2025 08:25:13 -0700, Jens Axboe wrote: >> On Tue, 14 Jan 2025 08:02:15 -0700, Jens Axboe wrote: >>>> diff --git a/block/genhd.c b/block/genhd.c >>>> index 9130e163e191..3a9c36ad6bbd 100644 >>>> --- a/block/genhd.c >>>> +++ b/block/genhd.c >>>> @@ -890,6 +890,9 @@ static int show_partition(struct seq_file *seqf, void *v) >>>> >>>> rcu_read_lock(); >>>> xa_for_each(&sgp->part_tbl, idx, part) { >>>> + int partno = bdev_partno(part); >>>> + >>>> + WARN_ON_ONCE(partno >= DISK_MAX_PARTS); >>>> if (!bdev_nr_sectors(part)) >>>> continue; >>>> seq_printf(seqf, "%4d %7d %10llu %pg\n", >>> >>> Surely you still want to continue for that condition? >> No. > >No? > >> But like following, ok? >> diff --git a/block/genhd.c b/block/genhd.c >> index 9130e163e191..142b13620f0c 100644 >> --- a/block/genhd.c >> +++ b/block/genhd.c >> @@ -890,7 +890,10 @@ static int show_partition(struct seq_file *seqf, void *v) >> >> rcu_read_lock(); >> xa_for_each(&sgp->part_tbl, idx, part) { >> - if (!bdev_nr_sectors(part)) >> + int partno = bdev_partno(part); >> + >> + WARN_ON_ONCE(partno >= DISK_MAX_PARTS); >> + if (!bdev_nr_sectors(part) || partno >= DISK_MAX_PARTS) >> continue; >> seq_printf(seqf, "%4d %7d %10llu %pg\n", >> MAJOR(part->bd_dev), MINOR(part->bd_dev), > >That's just silly... I checked WARN_ON_ONCE(), and when the condition is met, the subsequent WARN_ON_ONCE() will still return true, so adding it will not affect the judgment of the condition. It just issues a warning the first time the condition is met, and it will still return true if the condition is true. > > xa_for_each(&sgp->part_tbl, idx, part) { > int partno = bdev_partno(part); > > if (!bdev_nr_sectors(part)) > continue; > if (WARN_ON_ONCE(partno >= DISK_MAX_PARTS)) > continue; > > ... > } Edward