Re: [PATCH v6 1/4] block: Improve checks on zone resource limits

[Niklas Cassel <cassel@kernel.org>]

On Thu, Jun 06, 2024 at 05:21:44PM +0900, Damien Le Moal wrote:
> Make sure that the zone resource limits of a zoned block device are
> correct by checking that:
> (a) If the device has a max active zones limit, make sure that the max
>     open zones limit is lower than the max active zones limit.
> (b) If the device has zone resource limits, check that the limits
>     values are lower than the number of sequential zones of the device.
>     If it is not, assume that the zoned device has no limits by setting
>     the limits to 0.
> 
> For (a), a check is added to blk_validate_zoned_limits() and an error
> returned if the max open zones limit exceeds the value of the max active
> zone limit (if there is one).
> 
> For (b), given that we need the number of sequential zones of the zoned
> device, this check is added to disk_update_zone_resources(). This is
> safe to do as that function is executed with the disk queue frozen and
> the check executed after queue_limits_start_update() which takes the
> queue limits lock. Of note is that the early return in this function
> for zoned devices that do not use zone write plugging (e.g. DM devices
> using native zone append) is moved to after the new check and adjustment
> of the zone resource limits so that the check applies to any zoned
> device.
> 
> Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> ---

Reviewed-by: Niklas Cassel <cassel@kernel.org>