Re: [dm-devel] [PATCH 03/11] null_blk: don't set the discard_alignment queue limit

Damien Le Moal
2022-04-18T08:01:09Z

On 4/18/22 13:53, Christoph Hellwig wrote:
> The discard_alignment queue limit is named a bit misleading means the
> offset into the block device at which the discard granularity starts.
> Setting it to the discard granularity as done by null_blk is mostly
> harmless but also useless.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> drivers/block/null_blk/main.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
> index 5cb4c92cdffea..a521e914a9843 100644
> --- a/drivers/block/null_blk/main.c
> +++ b/drivers/block/null_blk/main.c
> @@ -1765,7 +1765,6 @@ static void null_config_discard(struct nullb *nullb)
> }
>
> nullb->q->limits.discard_granularity = nullb->dev->blocksize;
> - nullb->q->limits.discard_alignment = nullb->dev->blocksize;
> blk_queue_max_discard_sectors(nullb->q, UINT_MAX >> 9);
> }
>

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

--
Damien Le Moal
Western Digital Research