Re: [PATCH v9 6/7] scsi: libiscsi: use sendpage_ok() in iscsi_tcp_segment_map()

Lee Duncan
2020-10-01T16:10:23Z

On 10/1/20 12:54 AM, Coly Li wrote:
> In iscsci driver, iscsi_tcp_segment_map() uses the following code to
> check whether the page should or not be handled by sendpage:
> if (!recv && page_count(sg_page(sg)) >= 1 && !PageSlab(sg_page(sg)))
>
> The "page_count(sg_page(sg)) >= 1 && !PageSlab(sg_page(sg)" part is to
> make sure the page can be sent to network layer's zero copy path. This
> part is exactly what sendpage_ok() does.
>
> This patch uses use sendpage_ok() in iscsi_tcp_segment_map() to replace
> the original open coded checks.
>
> Signed-off-by: Coly Li <colyli@suse.de>
> Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
> Cc: Vasily Averin <vvs@virtuozzo.com>
> Cc: Cong Wang <amwang@redhat.com>
> Cc: Mike Christie <michaelc@cs.wisc.edu>
> Cc: Lee Duncan <lduncan@suse.com>
> Cc: Chris Leech <cleech@redhat.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Hannes Reinecke <hare@suse.de>
> ---
> drivers/scsi/libiscsi_tcp.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/scsi/libiscsi_tcp.c b/drivers/scsi/libiscsi_tcp.c
> index 37e5d4e48c2f..83f14b2c8804 100644
> --- a/drivers/scsi/libiscsi_tcp.c
> +++ b/drivers/scsi/libiscsi_tcp.c
> @@ -128,7 +128,7 @@ static void iscsi_tcp_segment_map(struct iscsi_segment *segment, int recv)
> * coalescing neighboring slab objects into a single frag which
> * triggers one of hardened usercopy checks.
> */
> - if (!recv && page_count(sg_page(sg)) >= 1 && !PageSlab(sg_page(sg)))
> + if (!recv && sendpage_ok(sg_page(sg)))
> return;
>
> if (recv) {
>

Reviewed-by: Lee Duncan <lduncan@suse.com>