NFS: Enable client side NFSv4.1 backchannel to use other transports

Forechannel transports get their own "bc_up" method to create an
endpoint for the backchannel service.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
[Anna Schumaker: Add forward declaration of struct net to xprt.h]
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

4 files changed, 35 insertions, 0 deletions

diff --git a/net/sunrpc/xprtrdma/backchannel.c b/net/sunrpc/xprtrdma/backchannel.c
index 0b3387fe3f0d..2dcb44f69e53 100644
--- a/net/sunrpc/xprtrdma/backchannel.c
+++ b/net/sunrpc/xprtrdma/backchannel.c
@@ -7,6 +7,7 @@
 #include <linux/module.h>
 #include <linux/sunrpc/xprt.h>
 #include <linux/sunrpc/svc.h>
+#include <linux/sunrpc/svc_xprt.h>
 
 #include "xprt_rdma.h"
 
@@ -174,6 +175,26 @@ out_err:
 }
 
 /**
+ * xprt_rdma_bc_up - Create transport endpoint for backchannel service
+ * @serv: server endpoint
+ * @net: network namespace
+ *
+ * The "xprt" is an implied argument: it supplies the name of the
+ * backchannel transport class.
+ *
+ * Returns zero on success, negative errno on failure
+ */
+int xprt_rdma_bc_up(struct svc_serv *serv, struct net *net)
+{
+        int ret;
+
+        ret = svc_create_xprt(serv, "rdma-bc", net, PF_INET, 0, 0);
+        if (ret < 0)
+                return ret;
+        return 0;
+}
+
+/**
  * rpcrdma_bc_marshal_reply - Send backwards direction reply
  * @rqst: buffer containing RPC reply data
  *
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index 845278e63be0..8c545f7d7525 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -708,6 +708,7 @@ static struct rpc_xprt_ops xprt_rdma_procs = {
         .inject_disconnect      = xprt_rdma_inject_disconnect,
 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
         .bc_setup               = xprt_rdma_bc_setup,
+        .bc_up                  = xprt_rdma_bc_up,
         .bc_free_rqst           = xprt_rdma_bc_free_rqst,
         .bc_destroy             = xprt_rdma_bc_destroy,
 #endif
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index eb87d96e80ca..f8dd17be9f43 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -520,6 +520,7 @@ void xprt_rdma_cleanup(void);
  */
 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int);
+int xprt_rdma_bc_up(struct svc_serv *, struct net *);
 int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int);
 void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *);
 int rpcrdma_bc_marshal_reply(struct rpc_rqst *);
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 44a81e4c6783..dc4706711224 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1306,6 +1306,17 @@ static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
                 xs_tcp_read_reply(xprt, desc) :
                 xs_tcp_read_callback(xprt, desc);
 }
+
+static int xs_tcp_bc_up(struct svc_serv *serv, struct net *net)
+{
+        int ret;
+
+        ret = svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
+                              SVC_SOCK_ANONYMOUS);
+        if (ret < 0)
+                return ret;
+        return 0;
+}
 #else
 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
                                         struct xdr_skb_reader *desc)
@@ -2582,6 +2593,7 @@ static struct rpc_xprt_ops xs_tcp_ops = {
         .inject_disconnect      = xs_inject_disconnect,
 #ifdef CONFIG_SUNRPC_BACKCHANNEL
         .bc_setup               = xprt_setup_bc,
+        .bc_up                  = xs_tcp_bc_up,
         .bc_free_rqst           = xprt_free_bc_rqst,
         .bc_destroy             = xprt_destroy_bc,
 #endif