Re: [PATCH 5/8] block: replace seq_zones_bitmap with conv_zones_bitmap

[Javier González <javier@xxxxxxxxxxx>]

On 03.12.2019 10:39, Christoph Hellwig wrote:
> Invert the meaning of seq_zones_bitmap by keeping a bitmap of
> conventional zones.  This allows not having a bitmap for devices
> that do not have conventional zones.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> block/blk-zoned.c      | 18 +++++++++---------
> include/linux/blkdev.h | 14 ++++++++------
> 2 files changed, 17 insertions(+), 15 deletions(-)
>
> diff --git a/block/blk-zoned.c b/block/blk-zoned.c
> index 65a9bdc9fe27..9c3931051f4f 100644
> --- a/block/blk-zoned.c
> +++ b/block/blk-zoned.c
> @@ -332,15 +332,15 @@ static inline unsigned long *blk_alloc_zone_bitmap(int node,
>
> void blk_queue_free_zone_bitmaps(struct request_queue *q)
> {
> -	kfree(q->seq_zones_bitmap);
> -	q->seq_zones_bitmap = NULL;
> +	kfree(q->conv_zones_bitmap);
> +	q->conv_zones_bitmap = NULL;
> 	kfree(q->seq_zones_wlock);
> 	q->seq_zones_wlock = NULL;
> }
>
> struct blk_revalidate_zone_args {
> 	struct gendisk	*disk;
> -	unsigned long	*seq_zones_bitmap;
> +	unsigned long	*conv_zones_bitmap;
> 	unsigned long	*seq_zones_wlock;
> 	sector_t	sector;
> };
> @@ -394,8 +394,8 @@ static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx,
> 		return -ENODEV;
> 	}
>
> -	if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL)
> -		set_bit(idx, args->seq_zones_bitmap);
> +	if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
> +		set_bit(idx, args->conv_zones_bitmap);
>
> 	args->sector += zone->len;
> 	return 0;
> @@ -415,8 +415,8 @@ static int blk_update_zone_info(struct gendisk *disk, unsigned int nr_zones,
> 	args->seq_zones_wlock = blk_alloc_zone_bitmap(q->node, nr_zones);
> 	if (!args->seq_zones_wlock)
> 		return -ENOMEM;
> -	args->seq_zones_bitmap = blk_alloc_zone_bitmap(q->node, nr_zones);
> -	if (!args->seq_zones_bitmap)
> +	args->conv_zones_bitmap = blk_alloc_zone_bitmap(q->node, nr_zones);
> +	if (!args->conv_zones_bitmap)
> 		return -ENOMEM;
>
> 	ret = disk->fops->report_zones(disk, 0, nr_zones,
> @@ -465,7 +465,7 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
> 	if (ret >= 0) {
> 		q->nr_zones = nr_zones;
> 		swap(q->seq_zones_wlock, args.seq_zones_wlock);
> -		swap(q->seq_zones_bitmap, args.seq_zones_bitmap);
> +		swap(q->conv_zones_bitmap, args.conv_zones_bitmap);
> 		ret = 0;
> 	} else {
> 		pr_warn("%s: failed to revalidate zones\n", disk->disk_name);
> @@ -474,7 +474,7 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
> 	blk_mq_unfreeze_queue(q);
>
> 	kfree(args.seq_zones_wlock);
> -	kfree(args.seq_zones_bitmap);
> +	kfree(args.conv_zones_bitmap);
> 	return ret;
> }
> EXPORT_SYMBOL_GPL(blk_revalidate_disk_zones);
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index c5852de402b6..503c4d4c5884 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -503,9 +503,9 @@ struct request_queue {
> 	/*
> 	 * Zoned block device information for request dispatch control.
> 	 * nr_zones is the total number of zones of the device. This is always
> -	 * 0 for regular block devices. seq_zones_bitmap is a bitmap of nr_zones
> -	 * bits which indicates if a zone is conventional (bit clear) or
> -	 * sequential (bit set). seq_zones_wlock is a bitmap of nr_zones
> +	 * 0 for regular block devices. conv_zones_bitmap is a bitmap of nr_zones
> +	 * bits which indicates if a zone is conventional (bit set) or
> +	 * sequential (bit clear). seq_zones_wlock is a bitmap of nr_zones
> 	 * bits which indicates if a zone is write locked, that is, if a write
> 	 * request targeting the zone was dispatched. All three fields are
> 	 * initialized by the low level device driver (e.g. scsi/sd.c).
> @@ -518,7 +518,7 @@ struct request_queue {
> 	 * blk_mq_unfreeze_queue().
> 	 */
> 	unsigned int		nr_zones;
> -	unsigned long		*seq_zones_bitmap;
> +	unsigned long		*conv_zones_bitmap;
> 	unsigned long		*seq_zones_wlock;
> #endif /* CONFIG_BLK_DEV_ZONED */
>
> @@ -723,9 +723,11 @@ static inline unsigned int blk_queue_zone_no(struct request_queue *q,
> static inline bool blk_queue_zone_is_seq(struct request_queue *q,
> 					 sector_t sector)
> {
> -	if (!blk_queue_is_zoned(q) || !q->seq_zones_bitmap)
> +	if (!blk_queue_is_zoned(q))
> 		return false;
> -	return test_bit(blk_queue_zone_no(q, sector), q->seq_zones_bitmap);
> +	if (!q->conv_zones_bitmap)
> +		return true;
> +	return !test_bit(blk_queue_zone_no(q, sector), q->conv_zones_bitmap);
> }
> #else /* CONFIG_BLK_DEV_ZONED */
> static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
> --
> 2.20.1

Looks good to me.

Reviewed-by: Javier González <javier@xxxxxxxxxxx>