From: Yufen Yu <yuyufen@huawei.com> mainline inclusion from mainline-5.10-rc1 commit f0c6ae09db1d39cbcf35776f889e0f7f861493d2 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I6HOKY CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h... --------------------------- After commit b89f625e28d4 ("block: don't release queue's sysfs lock during switching elevator"), whole elevator register and unregister function are covered by sysfs_lock. So, remove wrong comment and add lockdep assert. Signed-off-by: Yufen Yu <yuyufen@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com> Reviewed-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> --- block/elevator.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/block/elevator.c b/block/elevator.c index 77fde865bf7a..91c8769882d5 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -841,16 +841,13 @@ static struct kobj_type elv_ktype = { .release = elevator_release, }; -/* - * elv_register_queue is called from either blk_register_queue or - * elevator_switch, elevator switch is prevented from being happen - * in the two paths, so it is safe to not hold q->sysfs_lock. - */ int elv_register_queue(struct request_queue *q, bool uevent) { struct elevator_queue *e = q->elevator; int error; + lockdep_assert_held(&q->sysfs_lock); + error = kobject_add(&e->kobj, &q->kobj, "%s", "iosched"); if (!error) { struct elv_fs_entry *attr = e->type->elevator_attrs; @@ -871,13 +868,10 @@ int elv_register_queue(struct request_queue *q, bool uevent) return error; } -/* - * elv_unregister_queue is called from either blk_unregister_queue or - * elevator_switch, elevator switch is prevented from being happen - * in the two paths, so it is safe to not hold q->sysfs_lock. - */ void elv_unregister_queue(struct request_queue *q) { + lockdep_assert_held(&q->sysfs_lock); + if (q) { struct elevator_queue *e = q->elevator; -- 2.25.1