tcp: add tcp_sock_set_cork

Add a helper to directly set the TCP_CORK sockopt from kernel space
without going through a fake uaccess.  Cleanup the callers to avoid
pointless wrappers now that this is a simple function call.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 34 insertions, 26 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 970064996377..e6cf702e16d6 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2801,6 +2801,37 @@ static void tcp_enable_tx_delay(void)
 	}
 }
 
+/* When set indicates to always queue non-full frames.  Later the user clears
+ * this option and we transmit any pending partial frames in the queue.  This is
+ * meant to be used alongside sendfile() to get properly filled frames when the
+ * user (for example) must write out headers with a write() call first and then
+ * use sendfile to send out the data parts.
+ *
+ * TCP_CORK can be set together with TCP_NODELAY and it is stronger than
+ * TCP_NODELAY.
+ */
+static void __tcp_sock_set_cork(struct sock *sk, bool on)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (on) {
+		tp->nonagle |= TCP_NAGLE_CORK;
+	} else {
+		tp->nonagle &= ~TCP_NAGLE_CORK;
+		if (tp->nonagle & TCP_NAGLE_OFF)
+			tp->nonagle |= TCP_NAGLE_PUSH;
+		tcp_push_pending_frames(sk);
+	}
+}
+
+void tcp_sock_set_cork(struct sock *sk, bool on)
+{
+	lock_sock(sk);
+	__tcp_sock_set_cork(sk, on);
+	release_sock(sk);
+}
+EXPORT_SYMBOL(tcp_sock_set_cork);
+
 /*
  *	Socket option code for TCP.
  */
@@ -2979,25 +3010,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
 		break;
 
 	case TCP_CORK:
-		/* When set indicates to always queue non-full frames.
-		 * Later the user clears this option and we transmit
-		 * any pending partial frames in the queue.  This is
-		 * meant to be used alongside sendfile() to get properly
-		 * filled frames when the user (for example) must write
-		 * out headers with a write() call first and then use
-		 * sendfile to send out the data parts.
-		 *
-		 * TCP_CORK can be set together with TCP_NODELAY and it is
-		 * stronger than TCP_NODELAY.
-		 */
-		if (val) {
-			tp->nonagle |= TCP_NAGLE_CORK;
-		} else {
-			tp->nonagle &= ~TCP_NAGLE_CORK;
-			if (tp->nonagle&TCP_NAGLE_OFF)
-				tp->nonagle |= TCP_NAGLE_PUSH;
-			tcp_push_pending_frames(sk);
-		}
+		__tcp_sock_set_cork(sk, val);
 		break;
 
 	case TCP_KEEPIDLE:
diff --git a/net/rds/tcp_send.c b/net/rds/tcp_send.c
index 78a2554a4497..8c4d1d6e9249 100644
--- a/net/rds/tcp_send.c
+++ b/net/rds/tcp_send.c
@@ -38,23 +38,18 @@
 #include "rds.h"
 #include "tcp.h"
 
-static void rds_tcp_cork(struct socket *sock, int val)
-{
-	kernel_setsockopt(sock, SOL_TCP, TCP_CORK, (void *)&val, sizeof(val));
-}
-
 void rds_tcp_xmit_path_prepare(struct rds_conn_path *cp)
 {
 	struct rds_tcp_connection *tc = cp->cp_transport_data;
 
-	rds_tcp_cork(tc->t_sock, 1);
+	tcp_sock_set_cork(tc->t_sock->sk, true);
 }
 
 void rds_tcp_xmit_path_complete(struct rds_conn_path *cp)
 {
 	struct rds_tcp_connection *tc = cp->cp_transport_data;
 
-	rds_tcp_cork(tc->t_sock, 0);
+	tcp_sock_set_cork(tc->t_sock->sk, false);
 }
 
 /* the core send_sem serializes this with other xmit and shutdown */