[PATCH v2 3/4] SUNRPC: Ensure gss-proxy connects on setup

[trondmy@kernel.org]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

For reasons best known to the author, gss-proxy does not implement a
NULL procedure, and returns RPC_PROC_UNAVAIL. However we still want to
ensure that we connect to the service at setup time.
So add a quirk-flag specially for this case.

Fixes: 1d658336b05f ("SUNRPC: Add RPC based upcall mechanism for RPCGSS auth")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 include/linux/sunrpc/clnt.h          | 1 +
 net/sunrpc/auth_gss/gss_rpc_upcall.c | 2 +-
 net/sunrpc/clnt.c                    | 3 +++
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h
index 267b7aeaf1a6..db5149567305 100644
--- a/include/linux/sunrpc/clnt.h
+++ b/include/linux/sunrpc/clnt.h
@@ -160,6 +160,7 @@ struct rpc_add_xprt_test {
 #define RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT	(1UL << 9)
 #define RPC_CLNT_CREATE_SOFTERR		(1UL << 10)
 #define RPC_CLNT_CREATE_REUSEPORT	(1UL << 11)
+#define RPC_CLNT_CREATE_IGNORE_NULL_UNAVAIL (1UL << 12)
 
 struct rpc_clnt *rpc_create(struct rpc_create_args *args);
 struct rpc_clnt	*rpc_bind_new_program(struct rpc_clnt *,
diff --git a/net/sunrpc/auth_gss/gss_rpc_upcall.c b/net/sunrpc/auth_gss/gss_rpc_upcall.c
index 61c276bddaf2..8ca1d809b78d 100644
--- a/net/sunrpc/auth_gss/gss_rpc_upcall.c
+++ b/net/sunrpc/auth_gss/gss_rpc_upcall.c
@@ -97,7 +97,7 @@ static int gssp_rpc_create(struct net *net, struct rpc_clnt **_clnt)
 		 * timeout, which would result in reconnections being
 		 * done without the correct namespace:
 		 */
-		.flags		= RPC_CLNT_CREATE_NOPING |
+		.flags		= RPC_CLNT_CREATE_IGNORE_NULL_UNAVAIL |
 				  RPC_CLNT_CREATE_NO_IDLE_TIMEOUT
 	};
 	struct rpc_clnt *clnt;
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 98133aa54f19..22c28cf43eba 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -479,6 +479,9 @@ static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
 
 	if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 		int err = rpc_ping(clnt);
+		if ((args->flags & RPC_CLNT_CREATE_IGNORE_NULL_UNAVAIL) &&
+		    err == -EOPNOTSUPP)
+			err = 0;
 		if (err != 0) {
 			rpc_shutdown_client(clnt);
 			return ERR_PTR(err);
-- 
2.35.1