blk-mq-sched: (un)register elevator when (un)registering queue (80c6b157) · Commits · 戴 / test

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>

block/blk-sysfs.c

+10 −11

Original line number	Original line	Diff line number	Diff line
	@@ -903,9 +903,7 @@ int blk_register_queue(struct gendisk *disk)

	blk_wb_init(q);		blk_wb_init(q);

	if (!q->request_fn)		if (q->request_fn \|\| (q->mq_ops && q->elevator)) {
	return 0;

	ret = elv_register_queue(q);		ret = elv_register_queue(q);
	if (ret) {		if (ret) {
	kobject_uevent(&q->kobj, KOBJ_REMOVE);		kobject_uevent(&q->kobj, KOBJ_REMOVE);
	@@ -914,6 +912,7 @@ int blk_register_queue(struct gendisk *disk)
	kobject_put(&dev->kobj);		kobject_put(&dev->kobj);
	return ret;		return ret;
	}		}
			}

	return 0;		return 0;
	}		}
	@@ -928,7 +927,7 @@ void blk_unregister_queue(struct gendisk *disk)
	if (q->mq_ops)		if (q->mq_ops)
	blk_mq_unregister_dev(disk_to_dev(disk), q);		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);		elv_unregister_queue(q);

	kobject_uevent(&q->kobj, KOBJ_REMOVE);		kobject_uevent(&q->kobj, KOBJ_REMOVE);

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