Re: [PATCH v2 1/2] md: init queue_limits->max_hw_wzeroes_unmap_sectors parameter

[Hannes Reinecke <hare@suse.de>]

On 9/10/25 13:11, Zhang Yi wrote:
> From: Zhang Yi <yi.zhang@huawei.com>
> 
> 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, the stacked md drivers call md_init_stacking_limits() to
> initialize this parameter to UINT_MAX but only adjust
> max_write_zeroes_sectors when setting limits. Therefore, this
> discrepancy triggers a value check failure in blk_validate_limits().
> 
>   $ modprobe scsi_debug num_parts=2 dev_size_mb=8 lbprz=1 lbpws=1
>   $ mdadm --create /dev/md0 --level=0 --raid-device=2 /dev/sda1 /dev/sda2
>     mdadm: Defaulting to version 1.2 metadata
>     mdadm: RUN_ARRAY failed: Invalid argument
> 
> Fix this failure by explicitly setting max_hw_wzeroes_unmap_sectors to
> max_write_zeroes_sectors. Since the linear and raid0 drivers support
> write zeroes, so they can support unmap write zeroes operation if all of
> the backend devices support it. However, the raid1/10/5 drivers don't
> support write zeroes, so we have to set it to zero.
> 
> Fixes: 0c40d7cb5ef3 ("block: introduce max_{hw|user}_wzeroes_unmap_sectors to queue limits")
> Reported-by: John Garry <john.g.garry@oracle.com>
> Closes: https://lore.kernel.org/linux-block/803a2183-a0bb-4b7a-92f1-afc5097630d2@oracle.com/
> Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
> Tested-by: John Garry <john.g.garry@oracle.com>
> Reviewed-by: Li Nan <linan122@huawei.com>
> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
> Reviewed-by: Yu Kuai <yukuai3@huawei.com>
> ---
>   drivers/md/md-linear.c | 1 +
>   drivers/md/raid0.c     | 1 +
>   drivers/md/raid1.c     | 1 +
>   drivers/md/raid10.c    | 1 +
>   drivers/md/raid5.c     | 1 +
>   5 files changed, 5 insertions(+)
> 
Notice the failure, too. Thanks for fixing it.

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

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
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