rpc: allow xprt_class->setup to return a preexisting xprt
This allows us to reuse the xprt associated with a server connection if
one has already been set up.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 0ef4dd4..ee091c8 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -2359,6 +2359,15 @@
struct svc_sock *bc_sock;
struct rpc_xprt *ret;
+ if (args->bc_xprt->xpt_bc_xprt) {
+ /*
+ * This server connection already has a backchannel
+ * export; we can't create a new one, as we wouldn't be
+ * able to match replies based on xid any more. So,
+ * reuse the already-existing one:
+ */
+ return args->bc_xprt->xpt_bc_xprt;
+ }
xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries);
if (IS_ERR(xprt))
return xprt;
@@ -2397,15 +2406,6 @@
xprt->address_strings[RPC_DISPLAY_PROTO]);
/*
- * The backchannel uses the same socket connection as the
- * forechannel
- */
- if (args->bc_xprt->xpt_bc_xprt) {
- /* XXX: actually, want to catch this case... */
- ret = ERR_PTR(-EINVAL);
- goto out_err;
- }
- /*
* Once we've associated a backchannel xprt with a connection,
* we want to keep it around as long as long as the connection
* lasts, in case we need to start using it for a backchannel