Re: [PATCH 1/2] block: introduce zone capacity helper

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

On 3/12/25 10:31, Naohiro Aota wrote:
> {bdev,disk}_zone_capacity() takes block_device or gendisk and sector position
> and returns the zone capacity of the corresponding zone.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>  include/linux/blkdev.h | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
> 
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index d37751789bf5..3c860a0cf339 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -826,6 +826,27 @@ static inline u64 sb_bdev_nr_blocks(struct super_block *sb)
>  		(sb->s_blocksize_bits - SECTOR_SHIFT);
>  }
>  
> +#ifdef CONFIG_BLK_DEV_ZONED

There is already an "#ifdef CONFIG_BLK_DEV_ZONED" in blkdev.h, see
disk_nr_zones(). Please add this new helper under that ifdef to avoid adding a
new one.

> +static inline unsigned int disk_zone_capacity(struct gendisk *disk, sector_t pos)
> +{
> +	sector_t zone_sectors = disk->queue->limits.chunk_sectors;
> +
> +	if (pos + zone_sectors >= get_capacity(disk))
> +		return disk->last_zone_capacity;
> +	return disk->zone_capacity;
> +}
> +#else /* CONFIG_BLK_DEV_ZONED */
> +static inline unsigned int disk_zone_capacity(struct gendisk *disk, sector_t pos)

Is this ever called for a non zoned drive ? It should not be... So do we really
need this stub ?

> +{
> +	return 0;
> +}
> +#endif /* CONFIG_BLK_DEV_ZONED */
> +
> +static inline unsigned int bdev_zone_capacity(struct block_device *bdev, sector_t pos)
> +{
> +	return disk_zone_capacity(bdev->bd_disk, pos);
> +}
> +
>  int bdev_disk_changed(struct gendisk *disk, bool invalidate);
>  
>  void put_disk(struct gendisk *disk);


-- 
Damien Le Moal
Western Digital Research