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Subject: [PATCH v1] SUNRPC: Ensure backchannel transports are marked connected
From:   Chuck Lever <chuck.lever@oracle.com>
To:     linux-nfs@vger.kernel.org
Date:   Thu, 19 Aug 2021 08:29:24 -0400
Message-ID: <162937592206.2298.13447589794033256951.stgit@klimt.1015granger.net>
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With NFSv4.1+ on RDMA, backchannel recovery appears not to work.

xprt_setup_xxx_bc() is invoked by the client's first CREATE_SESSION
operation, and it always marks the rpc_clnt's transport as
connected.

On a subsequent CREATE_SESSION, if rpc_create() is called and
xpt_bc_xprt is populated, it might not be connected (for instance,
if a backchannel fault has occurred). Ensure that code path returns
a connected xprt also.

Reported-by: Timo Rothenpieler <timo@rothenpieler.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 net/sunrpc/clnt.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 8b4de70e8ead..570480a649a3 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -535,6 +535,7 @@ struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 		xprt = args->bc_xprt->xpt_bc_xprt;
 		if (xprt) {
 			xprt_get(xprt);
+			xprt_set_connected(xprt);
 			return rpc_create_xprt(args, xprt);
 		}
 	}