Re: [PATCH] scsi: storvsc: set max_segment_size as UINT_MAX explicitly

Wei Liu
2025-06-16T18:51:04Z

+Long for reviewing this patch.

On Tue, Jun 17, 2025 at 12:05:09AM +0800, Ming Lei wrote:
> Set max_segment_size as UINT_MAX explicitly:
>
> - storvrc uses virt_boundary to define `segment`
>
> - strovrc does not define max_segment_size
>

Typo here. It should be storvsc, not storvrc.

> So define max_segment_size as UINT_MAX, otherwise __blk_rq_map_sg() takes
> default 64K max segment size and splits one virtual segment into two parts,
> then breaks virt_boundary limit.
>
> Before commit ec84ca4025c0 ("scsi: block: Remove now unused queue limits helpers"),
> max segment size is set as UINT_MAX in case that virt_boundary is
> defined.
>
> Cc: "K. Y. Srinivasan" <kys@microsoft.com>
> Cc: Haiyang Zhang <haiyangz@microsoft.com>
> Cc: Wei Liu <wei.liu@kernel.org>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Ewan D. Milne <emilne@redhat.com>
> Cc: Laurence Oberman <loberman@redhat.com>
> Fixes: ec84ca4025c0 ("scsi: block: Remove now unused queue limits helpers")
> Signed-off-by: Ming Lei <ming.lei@redhat.com>
> ---
> drivers/scsi/storvsc_drv.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
> index 2e6b2412d2c9..1e7ad85f4ba3 100644
> --- a/drivers/scsi/storvsc_drv.c
> +++ b/drivers/scsi/storvsc_drv.c
> @@ -1897,6 +1897,7 @@ static struct scsi_host_template scsi_driver = {
> .no_write_same = 1,
> .track_queue_depth = 1,
> .change_queue_depth = storvsc_change_queue_depth,
> + .max_segment_size = 0xffffffff,
> };
>
> enum {
> --
> 2.47.0
>