@@ -67,6 +67,7 @@ struct svc_xprt {
#define XPT_CACHE_AUTH 11 /* cache auth info */
#define XPT_LOCAL 12 /* connection from loopback interface */
#define XPT_KILL_TEMP 13 /* call xpo_kill_temp_xprt before closing */
+#define XPT_CONG_CTRL 14 /* has reliable and ordered delivery, and congestion control */
struct svc_serv *xpt_server; /* service for transport */
atomic_t xpt_reserved; /* space on outq that is rsvd */
@@ -1306,6 +1306,7 @@ static void svc_tcp_init(struct svc_sock *svsk, struct svc_serv *serv)
svc_xprt_init(sock_net(svsk->sk_sock->sk), &svc_tcp_class,
&svsk->sk_xprt, serv);
set_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags);
+ set_bit(XPT_CONG_CTRL, &svsk->sk_xprt.xpt_flags);
if (sk->sk_state == TCP_LISTEN) {
dprintk("setting up TCP socket for listening\n");
set_bit(XPT_LISTENER, &svsk->sk_xprt.xpt_flags);
@@ -571,6 +571,14 @@ static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv,
spin_lock_init(&cma_xprt->sc_ctxt_lock);
spin_lock_init(&cma_xprt->sc_map_lock);
+ /*
+ * Note that this implies that the underlying transport support
+ * reliable and ordered delivery, and (generally) some form of
+ * congestion control. For now, we assume that all supported RDMA
+ * transports are suitable here.
+ */
+ set_bit(XPT_CONG_CTRL, &cma_xprt->sc_xprt.xpt_flags);
+
if (listener)
set_bit(XPT_LISTENER, &cma_xprt->sc_xprt.xpt_flags);
NFSv4 requires a transport protocol with reliable and ordered delivery, and congestion control in most cases. On an IP network, that means that NFSv4 over UDP should be forbidden. The situation with RDMA is a bit more nuanced, but most RDMA transports are suitable for this. For now, we assume that all RDMA transports are suitable, but we may need to revise that at some point. Signed-off-by: Jeff Layton <jlayton@redhat.com> --- include/linux/sunrpc/svc_xprt.h | 1 + net/sunrpc/svcsock.c | 1 + net/sunrpc/xprtrdma/svc_rdma_transport.c | 8 ++++++++ 3 files changed, 10 insertions(+)