Re: [PATCH v5 04/11] block: Introduce blk_rq_is_seq_zoned_write()

[Hannes Reinecke <hare@xxxxxxx>]

On 5/17/23 00:33, Bart Van Assche wrote:
> Introduce the function blk_rq_is_seq_zoned_write(). This function will
> be used in later patches to preserve the order of zoned writes that
> require write serialization.
>
> This patch includes an optimization: instead of using
> rq->q->disk->part0->bd_queue to check whether or not the queue is
> associated with a zoned block device, use rq->q->disk->queue.
>
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> Cc: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
> Cc: Ming Lei <ming.lei@xxxxxxxxxx>
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
> ---
>   block/blk-zoned.c      |  5 +----
>   include/linux/blk-mq.h | 16 ++++++++++++++++
>   2 files changed, 17 insertions(+), 4 deletions(-)
>
> diff --git a/block/blk-zoned.c b/block/blk-zoned.c
> index 835d9e937d4d..096b6b47561f 100644
> --- a/block/blk-zoned.c
> +++ b/block/blk-zoned.c
> @@ -60,10 +60,7 @@ bool blk_req_needs_zone_write_lock(struct request *rq)
>   	if (!rq->q->disk->seq_zones_wlock)
>   		return false;
>   
> -	if (bdev_op_is_zoned_write(rq->q->disk->part0, req_op(rq)))
> -		return blk_rq_zone_is_seq(rq);
> -
> -	return false;
> +	return blk_rq_is_seq_zoned_write(rq);
>   }
>   EXPORT_SYMBOL_GPL(blk_req_needs_zone_write_lock);
>   
> diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
> index 06caacd77ed6..301d72f85486 100644
> --- a/include/linux/blk-mq.h
> +++ b/include/linux/blk-mq.h
> @@ -1164,6 +1164,17 @@ static inline unsigned int blk_rq_zone_is_seq(struct request *rq)
>   	return disk_zone_is_seq(rq->q->disk, blk_rq_pos(rq));
>   }
>   
> +/**
> + * blk_rq_is_seq_zoned_write() - Check if @rq requires write serialization.
> + * @rq: Request to examine.
> + *
> + * Note: REQ_OP_ZONE_APPEND requests do not require serialization.
> + */
> +static inline bool blk_rq_is_seq_zoned_write(struct request *rq)
> +{
> +	return op_is_zoned_write(req_op(rq)) && blk_rq_zone_is_seq(rq);
> +}
> +
>   bool blk_req_needs_zone_write_lock(struct request *rq);
>   bool blk_req_zone_write_trylock(struct request *rq);
>   void __blk_req_zone_write_lock(struct request *rq);
> @@ -1194,6 +1205,11 @@ static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
>   	return !blk_req_zone_is_write_locked(rq);
>   }
>   #else /* CONFIG_BLK_DEV_ZONED */
> +static inline bool blk_rq_is_seq_zoned_write(struct request *rq)
> +{
> +	return false;
> +}
> +
>   static inline bool blk_req_needs_zone_write_lock(struct request *rq)
>   {
>   	return false;
Reviewed-by: Hannes Reinecke <hare@xxxxxxx>

Cheers,

Hannes
--
Dr. Hannes Reinecke                Kernel Storage Architect
hare@xxxxxxx                              +49 911 74053 688
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