Re: [PATCH AUTOSEL 6.6 18/18] null_blk: Do not allow runt zone with zone capacity smaller then zone size

["François Valenduc" <francoisvalenduc@gmail.com>]

Le 5/06/24 à 14:03, Sasha Levin a écrit :
> From: Damien Le Moal <dlemoal@kernel.org>
> 
> [ Upstream commit b164316808ec5de391c3e7b0148ec937d32d280d ]
> 
> 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@kernel.org>
> Reviewed-by: Niklas Cassel <cassel@kernel.org>
> Reviewed-by: Bart Van Assche <bvanassche@acm.org>
> Link: https://lore.kernel.org/r/20240530054035.491497-2-dlemoal@kernel.org
> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
>   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 55c5b48bc276f..9f6d7316b99aa 100644
> --- a/drivers/block/null_blk/zoned.c
> +++ b/drivers/block/null_blk/zoned.c
> @@ -83,6 +83,17 @@ int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q)
>   		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);

Is not 6.8 supposed to be end-of-life ?

François Valenduc