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From:   trondmy@kernel.org
To:     Anna Schumaker <Anna.Schumaker@netapp.com>
Cc:     linux-nfs@vger.kernel.org
Subject: [PATCH 2/2] SUNRPC: Tweak TCP socket shutdown in the RPC client
Date:   Tue, 24 Aug 2021 11:38:18 -0400
Message-Id: <20210824153818.322833-2-trondmy@kernel.org>
In-Reply-To: <20210824153818.322833-1-trondmy@kernel.org>
References: <20210824153818.322833-1-trondmy@kernel.org>
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From: Trond Myklebust <trond.myklebust@hammerspace.com>

We only really need to call shutdown() if we're in the ESTABLISHED TCP
state, since that is the only case where the client is initiating a
close of an established connection.

If the socket is in FIN_WAIT1 or FIN_WAIT2, then we've already initiated
socket shutdown and are waiting for the server's reply, so do nothing.

In all other cases where we've already received a FIN from the server,
we should be able to just close the socket.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 net/sunrpc/xprtsock.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 7e94f1d17edb..b91027d140df 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -2104,12 +2104,15 @@ static void xs_tcp_shutdown(struct rpc_xprt *xprt)
 		return;
 	}
 	switch (skst) {
-	default:
+	case TCP_FIN_WAIT1:
+	case TCP_FIN_WAIT2:
+		break;
+	case TCP_ESTABLISHED:
+	case TCP_CLOSE_WAIT:
 		kernel_sock_shutdown(sock, SHUT_RDWR);
 		trace_rpc_socket_shutdown(xprt, sock);
 		break;
-	case TCP_CLOSE:
-	case TCP_TIME_WAIT:
+	default:
 		xs_reset_transport(transport);
 	}
 }
-- 
2.31.1