Hello,
On Thu, Aug 09, 2018 at 07:53:36AM -0700, Bart Van Assche wrote:
> +/**
> + * blkg_lookup - look up blkg for the specified request queue
> + * @q: request_queue of interest
> + *
> + * Lookup blkg for @q at the root level. See also blkg_lookup().
> + */
> +static inline struct blkcg_gq *blkg_root_lookup(struct request_queue *q)
> +{
> + struct blkcg_gq *blkg;
> +
> + rcu_read_lock();
> + blkg = blkg_lookup(&blkcg_root, q);
> + rcu_read_unlock();
> +
> + return blkg;
> +}
So, root blkg is always available as long as the request_queue is
alive. Sth like the following would be simpler?
static inline struct blkcg_gq *blk_queue_root_blkg(struct request_queue *q)
{
return q->root_blkg;
}
--
tejun
