Re: [PATCH v2 2/2] drbd: init queue_limits->max_hw_wzeroes_unmap_sectors parameter

Hannes Reinecke <[email protected]> Wed, 10 Sep 2025 13:41:36 +0200
Newsgroups dev.linux.lists.drbd-dev,org.kernel.vger.linux-block,org.kernel.vger.linux-fsdevel,org.kernel.vger.linux-kernel,org.kernel.vger.linux-raid
Message-ID <[email protected]>
On 9/10/25 13:11, Zhang Yi wrote:
> From: Zhang Yi <[email protected]>
> 
> The parameter max_hw_wzeroes_unmap_sectors in queue_limits should be
> equal to max_write_zeroes_sectors if it is set to a non-zero value.
> However, when the backend bdev is specified, this parameter is
> initialized to UINT_MAX during the call to blk_set_stacking_limits(),
> while only max_write_zeroes_sectors is adjusted. Therefore, this
> discrepancy triggers a value check failure in blk_validate_limits().
> 
> Since the drvd driver doesn't yet support unmap write zeroes, so fix
> this failure by explicitly setting max_hw_wzeroes_unmap_sectors to
> zero.
> 
> Fixes: 0c40d7cb5ef3 ("block: introduce max_{hw|user}_wzeroes_unmap_sectors to queue limits")
> Signed-off-by: Zhang Yi <[email protected]>
> Reviewed-by: Martin K. Petersen <[email protected]>
> Reviewed-by: Yu Kuai <[email protected]>
> ---
>   drivers/block/drbd/drbd_nl.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
> index e09930c2b226..91f3b8afb63c 100644
> --- a/drivers/block/drbd/drbd_nl.c
> +++ b/drivers/block/drbd/drbd_nl.c
> @@ -1330,6 +1330,7 @@ void drbd_reconsider_queue_parameters(struct drbd_device *device,
>   		lim.max_write_zeroes_sectors = DRBD_MAX_BBIO_SECTORS;
>   	else
>   		lim.max_write_zeroes_sectors = 0;
> +	lim.max_hw_wzeroes_unmap_sectors = 0;
>   
>   	if ((lim.discard_granularity >> SECTOR_SHIFT) >
>   	    lim.max_hw_discard_sectors) {
Reviewed-by: Hannes Reinecke <[email protected]>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
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