nfs41: sunrpc: provide functions to create and destroy a svc_xprt for backchannel use

For nfs41 callbacks we need an svc_xprt to process requests coming up the
backchannel socket as rpc_rqst's that are transformed into svc_rqst's that
need a rq_xprt to be processed.

The svc_{udp,tcp}_create methods are too heavy for this job as svc_create_socket
creates an actual socket to listen on while for nfs41 we're "reusing" the
fore channel's socket.

Signed-off-by: Benny Halevy <bhalevy@panasas.com>

1 files changed, 39 insertions, 0 deletions

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 9d504234af4a..a2a03e500533 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1327,3 +1327,42 @@ static void svc_sock_free(struct svc_xprt *xprt)
                 sock_release(svsk->sk_sock);
         kfree(svsk);
 }
+
+/*
+ * Create a svc_xprt.
+ *
+ * For internal use only (e.g. nfsv4.1 backchannel).
+ * Callers should typically use the xpo_create() method.
+ */
+struct svc_xprt *svc_sock_create(struct svc_serv *serv, int prot)
+{
+        struct svc_sock *svsk;
+        struct svc_xprt *xprt = NULL;
+
+        dprintk("svc: %s\n", __func__);
+        svsk = kzalloc(sizeof(*svsk), GFP_KERNEL);
+        if (!svsk)
+                goto out;
+
+        xprt = &svsk->sk_xprt;
+        if (prot == IPPROTO_TCP)
+                svc_xprt_init(&svc_tcp_class, xprt, serv);
+        else if (prot == IPPROTO_UDP)
+                svc_xprt_init(&svc_udp_class, xprt, serv);
+        else
+                BUG();
+out:
+        dprintk("svc: %s return %p\n", __func__, xprt);
+        return xprt;
+}
+EXPORT_SYMBOL_GPL(svc_sock_create);
+
+/*
+ * Destroy a svc_sock.
+ */
+void svc_sock_destroy(struct svc_xprt *xprt)
+{
+        if (xprt)
+                kfree(container_of(xprt, struct svc_sock, sk_xprt));
+}
+EXPORT_SYMBOL_GPL(svc_sock_destroy);