From nobody Sun Mar 22 09:52:16 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 574C2336881 for ; Thu, 5 Mar 2026 04:06:02 +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=1772683562; cv=none; b=Ji3QkXXqJ0u1GO3EtjPH1ZhXbXmROld9hVzigDk/GJBRbSO4WBG4hmHDWwaRnaenAosmligpImbpBo9T/Kch5nY9iLig3nt/QAtrMH7uvU2I9ZJMcCfyEfC1sNivL//RpzAkP32E2cXohCgsbD+Kt7swbGF9wGdwLCZ4XWcdxPQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772683562; c=relaxed/simple; bh=uzsJa1Bqh20LQFOb4ZEawv08Hyzu04LYsaqJeWOJVmE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SoEd96HwkURwVifwYGS4i+uccZiooNfRdXOw0UN9p1LRnmZXQSo4vJzggm8ISMYDO98iHsIhPWR103ACm2hAHvw5f6wmpZeCc/cOiwsfcgzF4gpcRF4a3FYMCGOuSO3teGt19kqMDW1Rn8/J4OdJISbraS1X/mQrDFz3phfeffs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Zh2oi6YP; 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="Zh2oi6YP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 81D04C116C6; Thu, 5 Mar 2026 04:05:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772683562; bh=uzsJa1Bqh20LQFOb4ZEawv08Hyzu04LYsaqJeWOJVmE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Zh2oi6YPHbhU4kZJQ/zpvS8OdV+Z1ppLi1h+tgVLfJpME+zt64Gp2kjftNU1WJmON gSqPZVij1800NSMA8qf0mX0jCR+qLUc7CzAv817z4k7yDCw5WyjuAmvlYUpFQYrfg7 jggvw9agOSlGQm4wD2XNd4TxVaMtgIrqHvZ/65lUgApEP31Qczsmxvg7NaZibeYuA8 vm/CKo5qq+1vKhVpHkjyEJhR2TdAKA00XG9XoWsLkvTmSUNTvBOvAsLZxexAXdfm0/ W0j7XIbJ97TEYBWq2gecm/b8ikXEstz7ooXWHRDAowc14ZFYT5OkC3cTvShw//4QWz wE/HwkpBC9SFQ== From: Geliang Tang To: mptcp@lists.linux.dev, nilay@linux.ibm.com, ming.lei@redhat.com, hare@suse.de Cc: Geliang Tang , zhenwei pi , Hui Zhu , Gang Yan Subject: [RFC mptcp-next v4 6/8] mptcp: add sock_set_syncnt Date: Thu, 5 Mar 2026 12:05:24 +0800 Message-ID: <76939d6c3a650ef72430649a480e700ba0049f24.1772683110.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 applies it 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 --- drivers/nvme/host/tcp.c | 2 ++ include/net/mptcp.h | 7 +++++++ net/mptcp/protocol.c | 19 +++++++++++++++++++ 3 files changed, 28 insertions(+) diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index dc5b3ecdd885..8ead932e7999 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -1807,6 +1807,8 @@ static int nvme_tcp_alloc_queue(struct nvme_ctrl *nct= rl, int qid, nvme_tcp_reclassify_socket(queue->sock); =20 /* Single syn retry */ + sk_is_msk(queue->sock->sk) ? + mptcp_sock_set_syncnt(queue->sock->sk, 1) : tcp_sock_set_syncnt(queue->sock->sk, 1); =20 /* Set TCP no delay */ 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 61f4eba02b37..bc507b6e91e7 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -3838,6 +3838,25 @@ 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