Re: [PATCH v21 05/12] blk-zoned: Move code from disk_zone_wplug_add_bio() into its caller

[Damien Le Moal <dlemoal@kernel.org>]

On 7/18/25 05:58, Bart Van Assche wrote:
> Move the following code into the only caller of disk_zone_wplug_add_bio():
>  - The code for clearing the REQ_NOWAIT flag.
>  - The code that sets the BLK_ZONE_WPLUG_PLUGGED flag.
>  - The disk_zone_wplug_schedule_bio_work() call.
> 
> No functionality has been changed.
> 
> This patch prepares for zoned write pipelining by removing the code from
> disk_zone_wplug_add_bio() that does not apply to all zoned write pipelining
> bio processing cases.
> 
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>

[...]

> @@ -993,6 +976,7 @@ static bool blk_zone_wplug_handle_write(struct bio *bio, unsigned int nr_segs)
>  {
>  	struct gendisk *disk = bio->bi_bdev->bd_disk;
>  	sector_t sector = bio->bi_iter.bi_sector;
> +	bool schedule_bio_work = false;
>  	struct blk_zone_wplug *zwplug;
>  	gfp_t gfp_mask = GFP_NOIO;
>  	unsigned long flags;
> @@ -1039,12 +1023,16 @@ static bool blk_zone_wplug_handle_write(struct bio *bio, unsigned int nr_segs)
>  	 * Add REQ_NOWAIT BIOs to the plug list to ensure that we will not see a
>  	 * BLK_STS_AGAIN failure if we let the BIO execute.
>  	 */
> -	if (bio->bi_opf & REQ_NOWAIT)
> -		goto plug;
> +	if (bio->bi_opf & REQ_NOWAIT) {
> +		bio->bi_opf &= ~REQ_NOWAIT;
> +		if (!(zwplug->flags & BLK_ZONE_WPLUG_PLUGGED))
> +			goto plug;

See below.

> +		goto add_to_bio_list;
> +	}
>  
>  	/* If the zone is already plugged, add the BIO to the plug BIO list. */
>  	if (zwplug->flags & BLK_ZONE_WPLUG_PLUGGED)
> -		goto plug;
> +		goto add_to_bio_list;
>  
>  	if (!blk_zone_wplug_prepare_bio(zwplug, bio)) {
>  		spin_unlock_irqrestore(&zwplug->lock, flags);
> @@ -1060,7 +1048,13 @@ static bool blk_zone_wplug_handle_write(struct bio *bio, unsigned int nr_segs)
>  	return false;
>  
>  plug:
> +	zwplug->flags |= BLK_ZONE_WPLUG_PLUGGED;
> +	schedule_bio_work = true;

Since there is only a single "goto plug", I would simply move the 2 lines above
together with the goto plug and replace that goto with goto add_to_bio_list.

> +
> +add_to_bio_list:
>  	disk_zone_wplug_add_bio(disk, zwplug, bio, nr_segs);
> +	if (schedule_bio_work)
> +		disk_zone_wplug_schedule_bio_work(disk, zwplug);
>  
>  	spin_unlock_irqrestore(&zwplug->lock, flags);
>  


-- 
Damien Le Moal
Western Digital Research