Re: [PATCH v2 04/11] block: mq-deadline: Simplify deadline_skip_seq_writes()

[Christoph Hellwig <hch@lst.de>]

On Tue, Apr 18, 2023 at 03:39:55PM -0700, Bart Van Assche wrote:
> Make the deadline_skip_seq_writes() code shorter without changing its
> functionality.
> 
> Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Ming Lei <ming.lei@redhat.com>
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> ---
>  block/mq-deadline.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/block/mq-deadline.c b/block/mq-deadline.c
> index 5839a027e0f0..3dde720e2f59 100644
> --- a/block/mq-deadline.c
> +++ b/block/mq-deadline.c
> @@ -310,12 +310,9 @@ static struct request *deadline_skip_seq_writes(struct deadline_data *dd,
>  						struct request *rq)
>  {
>  	sector_t pos = blk_rq_pos(rq);
> -	sector_t skipped_sectors = 0;
>  
> -	while (rq) {
> -		if (blk_rq_pos(rq) != pos + skipped_sectors)
> -			break;
> -		skipped_sectors += blk_rq_sectors(rq);
> +	while (rq && blk_rq_pos(rq) == pos) {
> +		pos += blk_rq_sectors(rq);
>  		rq = deadline_latter_request(rq);
>  	}

This still reads a bit odd.

Maybe turn this into:

	do {
		pos += blk_rq_sectors(rq);
		rq = deadline_latter_request(rq);
		if (!rq)
			break;
	} while (blk_rq_pos(rq) == pos);