Re: [PATCH] block: tidy up blk_mq_plug

[Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>]

Looks good, we should avoid "!" conditions when possible it
makes code much easier to read.

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>

On 07/11/2019 04:17 AM, Christoph Hellwig wrote:
> Make the zoned device write path the special case and just fall
> though to the defaul case to make the code easier to read.  Also
> update the top of function comment to use the proper kdoc format
> and remove the extra in-function comments that just duplicate it.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   block/blk-mq.h | 14 ++++----------
>   1 file changed, 4 insertions(+), 10 deletions(-)
>
> diff --git a/block/blk-mq.h b/block/blk-mq.h
> index 32c62c64e6c2..ab80fd2b3803 100644
> --- a/block/blk-mq.h
> +++ b/block/blk-mq.h
> @@ -233,7 +233,7 @@ static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
>   		qmap->mq_map[cpu] = 0;
>   }
>
> -/*
> +/**
>    * blk_mq_plug() - Get caller context plug
>    * @q: request queue
>    * @bio : the bio being submitted by the caller context
> @@ -254,15 +254,9 @@ static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
>   static inline struct blk_plug *blk_mq_plug(struct request_queue *q,
>   					   struct bio *bio)
>   {
> -	/*
> -	 * For regular block devices or read operations, use the context plug
> -	 * which may be NULL if blk_start_plug() was not executed.
> -	 */
> -	if (!blk_queue_is_zoned(q) || !op_is_write(bio_op(bio)))
> -		return current->plug;
> -
> -	/* Zoned block device write operation case: do not plug the BIO */
> -	return NULL;
> +	if (blk_queue_is_zoned(q) && op_is_write(bio_op(bio)))
> +		return NULL;
> +	return current->plug;
>   }
>
>   #endif
>