From nobody Sun Mar 22 09:56:17 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D44F117A300 for ; Fri, 13 Mar 2026 04:13:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773375202; cv=none; b=ss9OaEFtK7gCPJQabyCxOgjW7axuVcSlD9rXdP+O73FG8jZcdoha/zw0m5Qo48PwERVkAS19lgRWbPnpqX6v8PxiSuAihaJj25J9SPz3jvFp1CQYoY4i2j0I5hXEaxtl+VLLlVkcUVqrDNga0IpamVLkaUcfY2+Kxe6ds/lu6H4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773375202; c=relaxed/simple; bh=+ZWitJQ36qz37QpYbpOlNA2mRboYOnrPwRBY58VwNJA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Ahw4btqqz5wLxyvlqD1h2nFsmlER3+5Af0uXpStajjtBhUEZaSqVIpLIcaZMduxIoIL00EfFnJigbhqbtFZyux142iWBArQ0PAw97I5ZmmQBcDwmsWq+3R4hkDZz9zyVW2IWl+ychMWM01e2BeXwPOTP0808sYHlEa8ejo76ijY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gl7XRFGf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gl7XRFGf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B2CBC19423; Fri, 13 Mar 2026 04:13:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773375202; bh=+ZWitJQ36qz37QpYbpOlNA2mRboYOnrPwRBY58VwNJA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gl7XRFGf3DRBq1PxoLp3mioR1shGZL43qR85cvXDY3iWYdAPo1fOXwaDzhxoHbcvt +2p9X+/34dI+ko5gLo8KJQ069gRUSYIpadq7QY6BdsCEPXTAFlmTGoFf3pNdep+O4c mZFrRYZqMZ1KxptlUSDTW4oVJQT8BLN3RiswJYQDYOfl0Tqy1fymLCDJyZYjxWoHRX TLKJZlzNxP2IIB0mOGGuHfoHhJ7YZlheODy/R8FPUSJ9C9bHjIVLGRuIoIhJgbzw0k 2tJ83pRp+650JBUWLy1QLR23eZwnw5Q35096zav6/+3rZUrc7ivl7VmBkfbBtKLpuh jtiCidK1yaZyQ== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang , zhenwei pi , Hui Zhu , Gang Yan Subject: [RFC mptcp-next v5 5/7] mptcp: add sock_set_syncnt Date: Fri, 13 Mar 2026 12:12:49 +0800 Message-ID: <7cd0862447c2d36dc844f94b7a09a8e31f6edcd2.1773374342.git.tanggeliang@kylinos.cn> X-Mailer: git-send-email 2.53.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Geliang Tang This patch introduces a dedicated MPTCP helper, sock_set_syncnt, which sets the SYN retransmission count on the first subflow socket and it will be applied to the host side in the 'NVMe over MPTCP' implementation. Co-developed-by: zhenwei pi Signed-off-by: zhenwei pi Co-developed-by: Hui Zhu Signed-off-by: Hui Zhu Co-developed-by: Gang Yan Signed-off-by: Gang Yan Signed-off-by: Geliang Tang --- include/net/mptcp.h | 7 +++++++ net/mptcp/protocol.c | 19 +++++++++++++++++++ 2 files changed, 26 insertions(+) diff --git a/include/net/mptcp.h b/include/net/mptcp.h index 63b64b7699e3..d6bb67a55f24 100644 --- a/include/net/mptcp.h +++ b/include/net/mptcp.h @@ -248,6 +248,8 @@ void mptcp_active_detect_blackhole(struct sock *sk, boo= l expired); void mptcp_sock_set_nodelay(struct sock *sk); =20 void mptcp_sock_set_reuseaddr(struct sock *sk); + +int mptcp_sock_set_syncnt(struct sock *sk, int val); #else =20 static inline void mptcp_init(void) @@ -343,6 +345,11 @@ static inline void mptcp_active_detect_blackhole(struc= t sock *sk, bool expired) static inline void mptcp_sock_set_nodelay(struct sock *sk) { } =20 static inline void mptcp_sock_set_reuseaddr(struct sock *sk) { } + +static inline int mptcp_sock_set_syncnt(struct sock *sk, int val) +{ + return 0; +} #endif /* CONFIG_MPTCP */ =20 #if IS_ENABLED(CONFIG_MPTCP_IPV6) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index bb923c4fabd1..961f11a24277 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -3834,6 +3834,25 @@ void mptcp_sock_set_reuseaddr(struct sock *sk) } EXPORT_SYMBOL(mptcp_sock_set_reuseaddr); =20 +int mptcp_sock_set_syncnt(struct sock *sk, int val) +{ + struct mptcp_sock *msk =3D mptcp_sk(sk); + struct sock *ssk; + + if (val < 1 || val > MAX_TCP_SYNCNT) + return -EINVAL; + + lock_sock(sk); + ssk =3D __mptcp_nmpc_sk(msk); + if (IS_ERR(ssk)) + goto unlock; + WRITE_ONCE(inet_csk(ssk)->icsk_syn_retries, val); +unlock: + release_sock(sk); + return 0; +} +EXPORT_SYMBOL(mptcp_sock_set_syncnt); + bool mptcp_finish_join(struct sock *ssk) { struct mptcp_subflow_context *subflow =3D mptcp_subflow_ctx(ssk); --=20 2.53.0