[dm-devel] [PATCH 01/11] dm-zoned: store zone id within the zone structure

[Damien Le Moal]

On 2020/04/07 2:26, Hannes Reinecke wrote:
> Instead of calculating the zone index by the offset within the
> zone array store the index within the structure itself.
> 
> Signed-off-by: Hannes Reinecke <hare at suse.de>
> ---
>  drivers/md/dm-zoned-metadata.c | 3 ++-
>  drivers/md/dm-zoned.h          | 3 +++
>  2 files changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/md/dm-zoned-metadata.c b/drivers/md/dm-zoned-metadata.c
> index c8787560fa9f..afce594067fb 100644
> --- a/drivers/md/dm-zoned-metadata.c
> +++ b/drivers/md/dm-zoned-metadata.c
> @@ -189,7 +189,7 @@ struct dmz_metadata {
>   */
>  unsigned int dmz_id(struct dmz_metadata *zmd, struct dm_zone *zone)
>  {
> -	return ((unsigned int)(zone - zmd->zones));
> +	return zone->id;

The zmd argument is now unused, and the helper does not make much sense anymore.
Why not just drop it entirely ? Callers directly referencing the ->id field of a
zone is simple and clear.

>  }
>  
>  sector_t dmz_start_sect(struct dmz_metadata *zmd, struct dm_zone *zone)
> @@ -1119,6 +1119,7 @@ static int dmz_init_zone(struct blk_zone *blkz, unsigned int idx, void *data)
>  
>  	INIT_LIST_HEAD(&zone->link);
>  	atomic_set(&zone->refcount, 0);
> +	zone->id = idx;
>  	zone->chunk = DMZ_MAP_UNMAPPED;
>  
>  	switch (blkz->type) {
> diff --git a/drivers/md/dm-zoned.h b/drivers/md/dm-zoned.h
> index 884c0e586082..39d59898abbe 100644
> --- a/drivers/md/dm-zoned.h
> +++ b/drivers/md/dm-zoned.h
> @@ -87,6 +87,9 @@ struct dm_zone {
>  	/* Zone activation reference count */
>  	atomic_t		refcount;
>  
> +	/* Zone id */
> +	unsigned int		id;
> +
>  	/* Zone write pointer block (relative to the zone start block) */
>  	unsigned int		wp_block;
>  
> 


-- 
Damien Le Moal
Western Digital Research