2020-10-01 07:58:37

by Coly Li

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

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 <[email protected]>
Acked-by: Martin K. Petersen <[email protected]>
Cc: Vasily Averin <[email protected]>
Cc: Cong Wang <[email protected]>
Cc: Mike Christie <[email protected]>
Cc: Lee Duncan <[email protected]>
Cc: Chris Leech <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Hannes Reinecke <[email protected]>
---
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) {
--
2.26.2

2020-10-01 16:12:07

by Lee Duncan

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

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 <[email protected]>
> Acked-by: Martin K. Petersen <[email protected]>
> Cc: Vasily Averin <[email protected]>
> Cc: Cong Wang <[email protected]>
> Cc: Mike Christie <[email protected]>
> Cc: Lee Duncan <[email protected]>
> Cc: Chris Leech <[email protected]>
> Cc: Christoph Hellwig <[email protected]>
> Cc: Hannes Reinecke <[email protected]>
> ---
> 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 <[email protected]>