diff mbox series

[1/4] null_blk: Do not allow runt zone with zone capacity smaller then zone size

Message ID 20240530054035.491497-2-dlemoal@kernel.org (mailing list archive)
State New, archived
Headers show
Series Zone write plugging and DM zone fixes | expand

Commit Message

Damien Le Moal May 30, 2024, 5:40 a.m. UTC
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>
---
 drivers/block/null_blk/zoned.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

Comments

Niklas Cassel May 30, 2024, 7:37 a.m. UTC | #1
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@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 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@kernel.org>
Bart Van Assche May 30, 2024, 8:34 p.m. UTC | #2
On 5/29/24 22:40, 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.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Christoph Hellwig June 1, 2024, 5:25 a.m. UTC | #3
Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>
Hannes Reinecke June 3, 2024, 6:53 a.m. UTC | #4
On 5/30/24 07:40, 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
                                       ^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>
> ---
>   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);

Otherwise:
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
diff mbox series

Patch

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);