Re: [PATCH 2/2] null_blk: don't finish zones to set them read-only or offline

[Niklas Cassel <cassel@kernel.org>]

On Thu, Oct 22, 2026 at 09:15:32AM +0200, Damien Le Moal wrote:
> On 2026/10/21 22:21, Niklas Cassel wrote:
> > null_set_zone_cond() calls null_finish_zone() to release the zone
> > resources held by a zone before setting it read-only or offline.
> > 
> > For an empty or closed zone, null_finish_zone() first runs the zone
> > resource checks, which can close an unrelated implicitly open zone, or
> > fail. As the error is ignored, a failure for a closed zone leaks
> > nr_zones_closed, permanently lowering the effective active zone limit.
> > 
> > Setting a zone read-only or offline requires no zone resources, so
> > release the zone resources held by the zone directly instead, using a
> > new helper, null_release_zone_resources().
> > 
> > Fixes: d3a5738849e0 ("null_blk: support read-only and offline zone conditions")
> > Signed-off-by: Niklas Cassel <cassel@kernel.org>
> 
> Looks good, modulo one nit below.
> 
> Reviewed-by: Damien Le Moal <dlemoal@kernel.org>

(snip)

> > @@ -768,9 +795,7 @@ static void null_set_zone_cond(struct nullb_device *dev,
> 
> This function is called only from zone_cond_store() with cond either
> BLK_ZONE_COND_READONLY or BLK_ZONE_COND_OFFLINE. Since your change is valid only
> for these 2 conditions, we really should check that cond is either of the
> already used values and add a comment, to avoid invalid use of
> null_set_zone_cond() in the future (without tweaking it).

Could you clarify with code what you mean?


For a comment, there is one already:
https://github.com/torvalds/linux/blob/v7.3/drivers/block/null_blk/zoned.c#L746

For a check that cond is either read-only or offline, there such a check
already:
https://github.com/torvalds/linux/blob/v7.3/drivers/block/null_blk/zoned.c#L751-L752


Kind regards,
Niklas