[PATCH] dm-table:remove the restriction on zone sector being align to pow2

[PATCH] dm-table:remove the restriction on zone sector being align to pow2

[Liao Yuanhong]

For zoned-UFS, sector size may not aligned to pow2, so we need to remove 
the pow2 limitation.

Signed-off-by: Liao Yuanhong <liaoyuanhong@vivo.com>
---
 drivers/md/dm-table.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 41f1d731ae5a..823f2f6a2d53 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1663,10 +1663,6 @@ static int validate_hardware_zoned(struct dm_table *t, bool zoned,
 		return -EINVAL;
 	}
 
-	/* Check zone size validity and compatibility */
-	if (!zone_sectors || !is_power_of_2(zone_sectors))
-		return -EINVAL;
-
 	if (dm_table_any_dev_attr(t, device_not_matches_zone_sectors, &zone_sectors)) {
 		DMERR("%s: zone sectors is not consistent across all zoned devices",
 		      dm_device_name(t->md));
-- 
2.25.1

Re: [PATCH] dm-table:remove the restriction on zone sector being align to pow2

[Benjamin Marzinski]

On Mon, Apr 29, 2024 at 10:50:29AM +0800, Liao Yuanhong wrote:
> For zoned-UFS, sector size may not aligned to pow2, so we need to remove 
> the pow2 limitation.

When was non-power-of-2 support added to zone devices? AFAIK, the last
attempt to add support for it was:

https://lore.kernel.org/dm-devel/20220923173618.6899-2-p.raghav@samsung.com/

Which was not merged. See that email thread for other necessary dm
changes to support this.

-Ben

> 
> Signed-off-by: Liao Yuanhong <liaoyuanhong@vivo.com>
> ---
>  drivers/md/dm-table.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
> index 41f1d731ae5a..823f2f6a2d53 100644
> --- a/drivers/md/dm-table.c
> +++ b/drivers/md/dm-table.c
> @@ -1663,10 +1663,6 @@ static int validate_hardware_zoned(struct dm_table *t, bool zoned,
>  		return -EINVAL;
>  	}
>  
> -	/* Check zone size validity and compatibility */
> -	if (!zone_sectors || !is_power_of_2(zone_sectors))
> -		return -EINVAL;
> -
>  	if (dm_table_any_dev_attr(t, device_not_matches_zone_sectors, &zone_sectors)) {
>  		DMERR("%s: zone sectors is not consistent across all zoned devices",
>  		      dm_device_name(t->md));
> -- 
> 2.25.1
> 

Re: [PATCH] dm-table:remove the restriction on zone sector being align to pow2

[Liao Yuanhong]

Currently, the zone size of the ZoneUFS provided by Hynix is not aligned
to pow2. After testing on the mobile platform with this fix, we found 
that basic functionality can be executed. May we merge this patch first?

Re: [PATCH] dm-table:remove the restriction on zone sector being align to pow2

[Benjamin Marzinski]

On Tue, Apr 30, 2024 at 11:32:07AM +0800, Liao Yuanhong wrote:
> Currently, the zone size of the ZoneUFS provided by Hynix is not aligned
> to pow2. After testing on the mobile platform with this fix, we found 
> that basic functionality can be executed. May we merge this patch first?

The issue is that device-mapper makes assumptions in multiple places
that zones are power of 2 sized. Simply removing this check will allow
users to create broken device-mapper devices on top of non-power-of-2
devices.

A better solution would be to see if Pankaj Raghav's non-power-of-2 zone
size patchset can be revisited.

-Ben