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From:   Coly Li <colyli@suse.de>
To:     linux-block@vger.kernel.org, linux-nvme@lists.infradead.org,
        netdev@vger.kernel.org, open-iscsi@googlegroups.com,
        linux-scsi@vger.kernel.org, ceph-devel@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org, Coly Li <colyli@suse.de>,
        Vasily Averin <vvs@virtuozzo.com>,
        Cong Wang <amwang@redhat.com>,
        Mike Christie <michaelc@cs.wisc.edu>,
        Lee Duncan <lduncan@suse.com>, Chris Leech <cleech@redhat.com>,
        Christoph Hellwig <hch@lst.de>, Hannes Reinecke <hare@suse.de>
Subject: [PATCH v6 5/6] scsi: libiscsi: use sendpage_ok() in iscsi_tcp_segment_map()
Date:   Tue, 18 Aug 2020 20:47:35 +0800
Message-Id: <20200818124736.5790-6-colyli@suse.de>
In-Reply-To: <20200818124736.5790-1-colyli@suse.de>
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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>
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 6ef93c7af954..31cd8487c16e 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