From: Geliang Tang <tanggeliang@kylinos.cn>

Implement an MPTCP-specific sock_set_nodelay helper, which will be used for
NVMe over MPTCP.

Co-developed-by: Hui Zhu <zhuhui@kylinos.cn>
Signed-off-by: Hui Zhu <zhuhui@kylinos.cn>
Co-developed-by: Gang Yan <yangang@kylinos.cn>
Signed-off-by: Gang Yan <yangang@kylinos.cn>
Co-developed-by: zhenwei pi <zhenwei.pi@linux.dev>
Signed-off-by: zhenwei pi <zhenwei.pi@linux.dev>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h  |  4 ++++
 net/mptcp/protocol.c | 18 ++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index c7bf444eee56..4fc8f08c6588 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -239,6 +239,8 @@ static inline __be32 mptcp_reset_option(const struct sk_buff *skb)
 void mptcp_active_detect_blackhole(struct sock *sk, bool expired);
 
 void mptcp_sock_set_reuseaddr(struct sock *sk);
+
+void mptcp_sock_set_nodelay(struct sock *sk);
 #else
 
 static inline void mptcp_init(void)
@@ -327,6 +329,8 @@ static inline __be32 mptcp_reset_option(const struct sk_buff *skb)  { return hto
 static inline void mptcp_active_detect_blackhole(struct sock *sk, bool expired) { }
 
 static inline void mptcp_sock_set_reuseaddr(struct sock *sk) { }
+
+static inline void mptcp_sock_set_nodelay(struct sock *sk) { }
 #endif /* CONFIG_MPTCP */
 
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 21067245a8f5..9790bc74a0b7 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -3779,6 +3779,24 @@ void mptcp_sock_set_reuseaddr(struct sock *sk)
 }
 EXPORT_SYMBOL(mptcp_sock_set_reuseaddr);
 
+void mptcp_sock_set_nodelay(struct sock *sk)
+{
+	struct mptcp_sock *msk = mptcp_sk(sk);
+	struct sock *ssk;
+
+	lock_sock(sk);
+	ssk = __mptcp_nmpc_sk(msk);
+	if (IS_ERR(ssk))
+		goto unlock;
+
+	lock_sock(ssk);
+	__tcp_sock_set_nodelay(ssk, true);
+	release_sock(ssk);
+unlock:
+	release_sock(sk);
+}
+EXPORT_SYMBOL(mptcp_sock_set_nodelay);
+
 bool mptcp_finish_join(struct sock *ssk)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
-- 
2.51.0