[ofa-general] [RFC, PATCH 01/20] svc: Add svc_xprt transport switch structure

[Tom Tucker]

Start moving to a transport switch for knfsd.  Add a svc_xprt
switch and move the sk_sendto and sk_recvfrom function
pointers into it.

Signed-off-by: Greg Banks <gnb at melbourne.sgi.com>
Signed-off-by: Peter Leckie <pleckie at melbourne.sgi.com>
Signed-off-by: Tom Tucker <tom at opengridcomputing.com>
---

 include/linux/sunrpc/svcsock.h |    9 +++++++--
 net/sunrpc/svcsock.c           |   22 ++++++++++++++++------
 2 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h
index e21dd93..4792ed6 100644
--- a/include/linux/sunrpc/svcsock.h
+++ b/include/linux/sunrpc/svcsock.h
@@ -11,6 +11,12 @@ #define SUNRPC_SVCSOCK_H
 
 #include <linux/sunrpc/svc.h>
 
+struct svc_xprt {
+	const char		*xpt_name;
+	int			(*xpt_recvfrom)(struct svc_rqst *rqstp);
+	int			(*xpt_sendto)(struct svc_rqst *rqstp);
+};
+
 /*
  * RPC server socket.
  */
@@ -43,8 +49,7 @@ #define	SK_DETACHED	10			/* detached fro
 						 * be revisted */
 	struct mutex		sk_mutex;	/* to serialize sending data */
 
-	int			(*sk_recvfrom)(struct svc_rqst *rqstp);
-	int			(*sk_sendto)(struct svc_rqst *rqstp);
+	const struct svc_xprt  *sk_xprt;
 
 	/* We keep the old state_change and data_ready CB's here */
 	void			(*sk_ostate)(struct sock *);
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 5baf48d..789d94a 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -885,6 +885,12 @@ svc_udp_sendto(struct svc_rqst *rqstp)
 	return error;
 }
 
+static const struct svc_xprt svc_udp_xprt = {
+	.xpt_name = "udp",
+	.xpt_recvfrom = svc_udp_recvfrom,
+	.xpt_sendto = svc_udp_sendto,
+};
+
 static void
 svc_udp_init(struct svc_sock *svsk)
 {
@@ -893,8 +899,7 @@ svc_udp_init(struct svc_sock *svsk)
 
 	svsk->sk_sk->sk_data_ready = svc_udp_data_ready;
 	svsk->sk_sk->sk_write_space = svc_write_space;
-	svsk->sk_recvfrom = svc_udp_recvfrom;
-	svsk->sk_sendto = svc_udp_sendto;
+	svsk->sk_xprt = &svc_udp_xprt;
 
 	/* initialise setting must have enough space to
 	 * receive and respond to one request.
@@ -1322,14 +1327,19 @@ svc_tcp_sendto(struct svc_rqst *rqstp)
 	return sent;
 }
 
+static const struct svc_xprt svc_tcp_xprt = {
+	.xpt_name = "tcp",
+	.xpt_recvfrom = svc_tcp_recvfrom,
+	.xpt_sendto = svc_tcp_sendto,
+};
+
 static void
 svc_tcp_init(struct svc_sock *svsk)
 {
 	struct sock	*sk = svsk->sk_sk;
 	struct tcp_sock *tp = tcp_sk(sk);
 
-	svsk->sk_recvfrom = svc_tcp_recvfrom;
-	svsk->sk_sendto = svc_tcp_sendto;
+	svsk->sk_xprt = &svc_tcp_xprt;
 
 	if (sk->sk_state == TCP_LISTEN) {
 		dprintk("setting up TCP socket for listening\n");
@@ -1477,7 +1487,7 @@ svc_recv(struct svc_rqst *rqstp, long ti
 
 	dprintk("svc: server %p, pool %u, socket %p, inuse=%d\n",
 		 rqstp, pool->sp_id, svsk, atomic_read(&svsk->sk_inuse));
-	len = svsk->sk_recvfrom(rqstp);
+	len = svsk->sk_xprt->xpt_recvfrom(rqstp);
 	dprintk("svc: got len=%d\n", len);
 
 	/* No data, incomplete (TCP) read, or accept() */
@@ -1537,7 +1547,7 @@ svc_send(struct svc_rqst *rqstp)
 	if (test_bit(SK_DEAD, &svsk->sk_flags))
 		len = -ENOTCONN;
 	else
-		len = svsk->sk_sendto(rqstp);
+		len = svsk->sk_xprt->xpt_sendto(rqstp);
 	mutex_unlock(&svsk->sk_mutex);
 	svc_sock_release(rqstp);