On Thu, May 30, 2024 at 02:40:32PM +0900, Damien Le Moal wrote:
> A zoned device with a smaller last zone together with a zone capacity
> smaller than the zone size does make any sense as that does not
> correspond to any possible setup for a real device:
> 1) For ZNS and zoned UFS devices, all zones are always the same size.
> 2) For SMR HDDs, all zones always have the same capacity.
> In other words, if we have a smaller last runt zone, then this zone
> capacity should always be equal to the zone size.
>
> Add a check in null_init_zoned_dev() to prevent a configuration to have
> both a smaller zone size and a zone capacity smaller than the zone size.
>
> Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
> ---
> drivers/block/null_blk/zoned.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/drivers/block/null_blk/zoned.c b/drivers/block/null_blk/zoned.c
> index 79c8e5e99f7f..f118d304f310 100644
> --- a/drivers/block/null_blk/zoned.c
> +++ b/drivers/block/null_blk/zoned.c
> @@ -74,6 +74,17 @@ int null_init_zoned_dev(struct nullb_device *dev,
> return -EINVAL;
> }
>
> + /*
> + * If a smaller zone capacity was requested, do not allow a smaller last
> + * zone at the same time as such zone configuration does not correspond
> + * to any real zoned device.
> + */
> + if (dev->zone_capacity != dev->zone_size &&
> + dev->size & (dev->zone_size - 1)) {
> + pr_err("A smaller last zone is not allowed with zone capacity smaller than zone size.\n");
> + return -EINVAL;
> + }
> +
> zone_capacity_sects = mb_to_sects(dev->zone_capacity);
> dev_capacity_sects = mb_to_sects(dev->size);
> dev->zone_size_sects = mb_to_sects(dev->zone_size);
> --
> 2.45.1
>
Reviewed-by: Niklas Cassel <cassel@xxxxxxxxxx>
