On Wed, Sep 13, 2017 at 02:38:20PM -0700, Tejun Heo wrote:

Maybe doing sth like the following is less error-prone?

kthread_associate_blkcg(@css)
{
	if (current's kthread->blkcg_css)
		put kthread->blkcg_css and set it to NULL;
	if (@css)
		get @css and set kthread->blkcg;
}

Ooh, also, maybe add a WARN_ON_ONCE on non-NULL blkcg_css on kthread
exit?

Thanks.

-- 
tejun