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From:   Guangguan Wang <guangguan.wang@linux.alibaba.com>
To:     kgraul@linux.ibm.com, davem@davemloft.net, kuba@kernel.org,
        tonylu@linux.alibaba.com
Cc:     linux-s390@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH net v2] net/smc: non blocking recvmsg() return -EAGAIN when no data and signal_pending
Date:   Thu, 12 May 2022 11:08:20 +0800
Message-Id: <20220512030820.73848-1-guangguan.wang@linux.alibaba.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Non blocking sendmsg will return -EAGAIN when any signal pending
and no send space left, while non blocking recvmsg return -EINTR
when signal pending and no data received. This may makes confused.
As TCP returns -EAGAIN in the conditions described above. Align the
behavior of smc with TCP.

Fixes: 846e344eb722 ("net/smc: add receive timeout check")
Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
---
 net/smc/smc_rx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/smc/smc_rx.c b/net/smc/smc_rx.c
index 51e8eb2933ff..338b9ef806e8 100644
--- a/net/smc/smc_rx.c
+++ b/net/smc/smc_rx.c
@@ -355,12 +355,12 @@ int smc_rx_recvmsg(struct smc_sock *smc, struct msghdr *msg,
 				}
 				break;
 			}
+			if (!timeo)
+				return -EAGAIN;
 			if (signal_pending(current)) {
 				read_done = sock_intr_errno(timeo);
 				break;
 			}
-			if (!timeo)
-				return -EAGAIN;
 		}
 
 		if (!smc_rx_data_available(conn)) {
-- 
2.24.3 (Apple Git-128)