Re: [PATCH 2/3] block: Separate zone requests from medium access requests

[Bart Van Assche <Bart.VanAssche@sandisk.com>]

On Tue, 2017-02-28 at 19:25 +0900, Damien Le Moal wrote:
> From: Bart Van Assche <bart.vanassche@sandisk.com>
> 
> Use blk_rq_accesses_medium() instead of !blk_rq_is_passthrough() to
> ensure that code that is intended for normal medium access requests,
> e.g. DISCARD, READ and WRITE requests, is not applied to
> REQ_OP_ZONE_REPORT requests nor to REQ_OP_ZONE_RESET requests.
> This allows excluding these zone requests from request accounting
> and from request scheduling.
> 
> Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>

Hello Damien,

Since you posted this patch you should have added your Signed-off-by. And
since you have edited this patch, you should have documented what you have
changed.

>  static inline void req_set_nomerge(struct request_queue *q, struct request *req)
> diff --git a/block/elevator.c b/block/elevator.c
> index 699d10f..cbf81c6 100644
> --- a/block/elevator.c
> +++ b/block/elevator.c
> @@ -635,16 +635,20 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where)
>  
>  	rq->q = q;
>  
> -	if (rq->rq_flags & RQF_SOFTBARRIER) {
> +	if (!blk_rq_accesses_medium(rq)) {
> +		/* Do not schedule zone requests */
> +		where = ELEVATOR_INSERT_FRONT;
> +	} if (rq->rq_flags & RQF_SOFTBARRIER) {

This change was not in the patch I sent to you. Additionally, this change
doesn't look properly formatted. Please make sure that the second "if" starts
on a new line.

>  		}
>  	} else if (!(rq->rq_flags & RQF_ELVPRIV) &&
>  		    (where == ELEVATOR_INSERT_SORT ||
> -		     where == ELEVATOR_INSERT_SORT_MERGE))
> +		     where == ELEVATOR_INSERT_SORT_MERGE)) {
>  		where = ELEVATOR_INSERT_BACK;
> +	}

This change wasn't in my patch either. Since this change only adds a pair of
braces, can it be left out?

Thanks,

Bart.