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From:   David Howells <dhowells@redhat.com>
To:     Matthew Wilcox <willy@infradead.org>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>
Cc:     David Howells <dhowells@redhat.com>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Christoph Hellwig <hch@infradead.org>,
        Jens Axboe <axboe@kernel.dk>, Jeff Layton <jlayton@kernel.org>,
        Christian Brauner <brauner@kernel.org>,
        Chuck Lever III <chuck.lever@oracle.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        netdev@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        linux-scsi@vger.kernel.org, target-devel@vger.kernel.org
Subject: [RFC PATCH v2 33/48] iscsi: Assume "sendpage" is okay in iscsi_tcp_segment_map()
Date:   Wed, 29 Mar 2023 15:13:39 +0100
Message-Id: <20230329141354.516864-34-dhowells@redhat.com>
In-Reply-To: <20230329141354.516864-1-dhowells@redhat.com>
References: <20230329141354.516864-1-dhowells@redhat.com>
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As iscsi is now using sendmsg() with MSG_SPLICE_PAGES rather than sendpage,
assume that sendpage_ok() will return true in iscsi_tcp_segment_map() and
leave it to TCP to copy the data if not.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: "Martin K. Petersen" <martin.petersen@oracle.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
cc: linux-scsi@vger.kernel.org
cc: target-devel@vger.kernel.org
cc: netdev@vger.kernel.org
---
 drivers/scsi/libiscsi_tcp.c | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/drivers/scsi/libiscsi_tcp.c b/drivers/scsi/libiscsi_tcp.c
index c182aa83f2c9..07ba0d864820 100644
--- a/drivers/scsi/libiscsi_tcp.c
+++ b/drivers/scsi/libiscsi_tcp.c
@@ -128,18 +128,11 @@ 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 && sendpage_ok(sg_page(sg)))
+	if (!recv)
 		return;
 
-	if (recv) {
-		segment->atomic_mapped = true;
-		segment->sg_mapped = kmap_atomic(sg_page(sg));
-	} else {
-		segment->atomic_mapped = false;
-		/* the xmit path can sleep with the page mapped so use kmap */
-		segment->sg_mapped = kmap(sg_page(sg));
-	}
-
+	segment->atomic_mapped = true;
+	segment->sg_mapped = kmap_atomic(sg_page(sg));
 	segment->data = segment->sg_mapped + sg->offset + segment->sg_offset;
 }