Re: [PATCHv2 2/3] block: export dma_alignment attribute

[Bart Van Assche <bvanassche@acm.org>]

On 5/18/22 19:11, Keith Busch wrote:
> From: Keith Busch <kbusch@kernel.org>
> 
> User space may want to know how to align their buffers to avoid
> bouncing. Export the queue attribute.
> 
> Signed-off-by: Keith Busch <kbusch@kernel.org>
> ---
>   block/blk-sysfs.c | 7 +++++++
>   1 file changed, 7 insertions(+)
> 
> diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
> index 88bd41d4cb59..14607565d781 100644
> --- a/block/blk-sysfs.c
> +++ b/block/blk-sysfs.c
> @@ -274,6 +274,11 @@ static ssize_t queue_virt_boundary_mask_show(struct request_queue *q, char *page
>   	return queue_var_show(q->limits.virt_boundary_mask, page);
>   }
>   
> +static ssize_t queue_dma_alignment_show(struct request_queue *q, char *page)
> +{
> +	return queue_var_show(queue_dma_alignment(q), page);
> +}
> +
>   #define QUEUE_SYSFS_BIT_FNS(name, flag, neg)				\
>   static ssize_t								\
>   queue_##name##_show(struct request_queue *q, char *page)		\
> @@ -606,6 +611,7 @@ QUEUE_RO_ENTRY(queue_dax, "dax");
>   QUEUE_RW_ENTRY(queue_io_timeout, "io_timeout");
>   QUEUE_RW_ENTRY(queue_wb_lat, "wbt_lat_usec");
>   QUEUE_RO_ENTRY(queue_virt_boundary_mask, "virt_boundary_mask");
> +QUEUE_RO_ENTRY(queue_dma_alignment, "dma_alignment");
>   
>   #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
>   QUEUE_RW_ENTRY(blk_throtl_sample_time, "throttle_sample_time");
> @@ -667,6 +673,7 @@ static struct attribute *queue_attrs[] = {
>   	&blk_throtl_sample_time_entry.attr,
>   #endif
>   	&queue_virt_boundary_mask_entry.attr,
> +	&queue_dma_alignment_entry.attr,
>   	NULL,
>   };

Please add an entry for the new sysfs attribute in 
Documentation/ABI/stable/sysfs-block.

Thanks,

Bart.