svc: Add per-transport delete functions

Add transport specific xpo_detach and xpo_free functions. The xpo_detach
function causes the transport to stop delivering data-ready events
and enqueing the transport for I/O.

The xpo_free function frees all resources associated with the particular
transport instance.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Acked-by: Neil Brown <neilb@suse.de>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Greg Banks <gnb@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

include/linux/sunrpc/svc_xprt.h

@@ -13,6 +13,8 @@ struct svc_xprt_ops {
 	int		(*xpo_recvfrom)(struct svc_rqst *);
 	int		(*xpo_sendto)(struct svc_rqst *);
 	void		(*xpo_release_rqst)(struct svc_rqst *);
+	void		(*xpo_detach)(struct svc_xprt *);
+	void		(*xpo_free)(struct svc_xprt *);
 };
 
 struct svc_xprt_class {

net/sunrpc/svcsock.c

@@ -85,6 +85,8 @@ static void		svc_udp_data_ready(struct sock *, int);
 static int		svc_udp_recvfrom(struct svc_rqst *);
 static int		svc_udp_sendto(struct svc_rqst *);
 static void		svc_close_socket(struct svc_sock *svsk);
+static void		svc_sock_detach(struct svc_xprt *);
+static void		svc_sock_free(struct svc_xprt *);
 
 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_sock *svsk);
 static int svc_deferred_recv(struct svc_rqst *rqstp);
@@ -376,16 +378,8 @@ static inline void
 svc_sock_put(struct svc_sock *svsk)
 {
 	if (atomic_dec_and_test(&svsk->sk_inuse)) {
-		BUG_ON(! test_bit(SK_DEAD, &svsk->sk_flags));
-
-		dprintk("svc: releasing dead socket\n");
-		if (svsk->sk_sock->file)
-			sockfd_put(svsk->sk_sock);
-		else
-			sock_release(svsk->sk_sock);
-		if (svsk->sk_info_authunix != NULL)
-			svcauth_unix_info_release(svsk->sk_info_authunix);
-		kfree(svsk);
+		BUG_ON(!test_bit(SK_DEAD, &svsk->sk_flags));
+		svsk->sk_xprt.xpt_ops->xpo_free(&svsk->sk_xprt);
 	}
 }
 
@@ -903,6 +897,8 @@ static struct svc_xprt_ops svc_udp_ops = {
 	.xpo_recvfrom = svc_udp_recvfrom,
 	.xpo_sendto = svc_udp_sendto,
 	.xpo_release_rqst = svc_release_skb,
+	.xpo_detach = svc_sock_detach,
+	.xpo_free = svc_sock_free,
 };
 
 static struct svc_xprt_class svc_udp_class = {
@@ -1358,6 +1354,8 @@ static struct svc_xprt_ops svc_tcp_ops = {
 	.xpo_recvfrom = svc_tcp_recvfrom,
 	.xpo_sendto = svc_tcp_sendto,
 	.xpo_release_rqst = svc_release_skb,
+	.xpo_detach = svc_sock_detach,
+	.xpo_free = svc_sock_free,
 };
 
 static struct svc_xprt_class svc_tcp_class = {
@@ -1814,6 +1812,40 @@ static int svc_create_socket(struct svc_serv *serv, int protocol,
 	return error;
 }
 
+/*
+ * Detach the svc_sock from the socket so that no
+ * more callbacks occur.
+ */
+static void svc_sock_detach(struct svc_xprt *xprt)
+{
+	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
+	struct sock *sk = svsk->sk_sk;
+
+	dprintk("svc: svc_sock_detach(%p)\n", svsk);
+
+	/* put back the old socket callbacks */
+	sk->sk_state_change = svsk->sk_ostate;
+	sk->sk_data_ready = svsk->sk_odata;
+	sk->sk_write_space = svsk->sk_owspace;
+}
+
+/*
+ * Free the svc_sock's socket resources and the svc_sock itself.
+ */
+static void svc_sock_free(struct svc_xprt *xprt)
+{
+	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
+	dprintk("svc: svc_sock_free(%p)\n", svsk);
+
+	if (svsk->sk_info_authunix != NULL)
+		svcauth_unix_info_release(svsk->sk_info_authunix);
+	if (svsk->sk_sock->file)
+		sockfd_put(svsk->sk_sock);
+	else
+		sock_release(svsk->sk_sock);
+	kfree(svsk);
+}
+
 /*
  * Remove a dead socket
  */
@@ -1828,9 +1860,7 @@ svc_delete_socket(struct svc_sock *svsk)
 	serv = svsk->sk_server;
 	sk = svsk->sk_sk;
 
-	sk->sk_state_change = svsk->sk_ostate;
-	sk->sk_data_ready = svsk->sk_odata;
-	sk->sk_write_space = svsk->sk_owspace;
+	svsk->sk_xprt.xpt_ops->xpo_detach(&svsk->sk_xprt);
 
 	spin_lock_bh(&serv->sv_lock);