diff mbox series

[RFC,net-next,06/20] net/smc: fast return on unconcernd TCP options

Message ID 1708412505-34470-7-git-send-email-alibuda@linux.alibaba.com (mailing list archive)
State Superseded
Headers show
Series Introduce IPPROTO_SMC | expand

Commit Message

D. Wythe Feb. 20, 2024, 7:01 a.m. UTC 
From: "D. Wythe" <alibuda@linux.alibaba.com>

SMC does not require additional processing of every TCP options,
hence that when options that do not require additional processing,
we can immediately return.

Note that options which are explicitly not supported require a try
to fallback, and shall not simplt returned.

Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
---
 net/smc/af_smc.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)
diff mbox series

Patch

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index b7c9f5c..40cf0569 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -3054,6 +3054,28 @@  static inline bool smc_is_unsupport_tcp_sockopt(int optname)
 	return false;
 }
 
+/* Return true if smc might modify the semantics of
+ * the imcoming TCP options. Specifically, it includes
+ * unsupported TCP options.
+ */
+static inline bool smc_need_override_tcp_sockopt(struct sock *sk, int optname)
+{
+	switch (optname) {
+	case TCP_NODELAY:
+	case TCP_CORK:
+		if (smc_sk_state(sk) == SMC_INIT ||
+		    smc_sk_state(sk) == SMC_LISTEN ||
+		    smc_sk_state(sk) == SMC_CLOSED)
+			return false;
+		fallthrough;
+	case TCP_DEFER_ACCEPT:
+		return true;
+	default:
+		break;
+	}
+	return smc_is_unsupport_tcp_sockopt(optname);
+}
+
 static int smc_setsockopt_common(struct socket *sock, int level, int optname,
 				 sockptr_t optval, unsigned int optlen)
 {
@@ -3063,6 +3085,10 @@  static int smc_setsockopt_common(struct socket *sock, int level, int optname,
 
 	smc = smc_sk(sk);
 
+	/* Fast path, just go away if no extra action needed */
+	if (!smc_need_override_tcp_sockopt(sk, optname))
+		return 0;
+
 	if (optlen < sizeof(int))
 		return -EINVAL;
 	if (copy_from_sockptr(&val, optval, sizeof(int)))