blk-mq-sched: (un)register elevator when (un)registering queue

I noticed that when booting with a default blk-mq I/O scheduler, the
/sys/block/*/queue/iosched directory was missing. However, switching
after boot did create the directory. This is because we skip the initial
elevator register/unregister when we don't have a ->request_fn(), but we
should still do it for the ->mq_ops case.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Omar Sandoval 2017-02-06 12:52:24 -08:00 committed by Jens Axboe
parent e980f62353
commit 80c6b15732

View File

@ -903,16 +903,15 @@ int blk_register_queue(struct gendisk *disk)
blk_wb_init(q);
if (!q->request_fn)
return 0;
ret = elv_register_queue(q);
if (ret) {
kobject_uevent(&q->kobj, KOBJ_REMOVE);
kobject_del(&q->kobj);
blk_trace_remove_sysfs(dev);
kobject_put(&dev->kobj);
return ret;
if (q->request_fn || (q->mq_ops && q->elevator)) {
ret = elv_register_queue(q);
if (ret) {
kobject_uevent(&q->kobj, KOBJ_REMOVE);
kobject_del(&q->kobj);
blk_trace_remove_sysfs(dev);
kobject_put(&dev->kobj);
return ret;
}
}
return 0;
@ -928,7 +927,7 @@ void blk_unregister_queue(struct gendisk *disk)
if (q->mq_ops)
blk_mq_unregister_dev(disk_to_dev(disk), q);
if (q->request_fn)
if (q->request_fn || (q->mq_ops && q->elevator))
elv_unregister_queue(q);
kobject_uevent(&q->kobj, KOBJ_REMOVE);