> +/*
> + * Returns true if request was not in flight.
> + */
> +static inline bool blk_mq_mark_complete(struct request *rq)
> +{
> + return (cmpxchg(&rq->state, MQ_RQ_IN_FLIGHT, MQ_RQ_COMPLETE) !=
> + MQ_RQ_IN_FLIGHT);
> +}
This needs a much better comment describing when and how to use it.
Also the outer braces in the return statement are not required.
