From nobody Mon Feb 9 10:47:52 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 8F411388874; Fri, 30 Jan 2026 19:24:53 +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=1769801093; cv=none; b=Fu0YrO1EKZaZkkLXBqYGa/prLUrH896XbQLE2yFP1CqOQeaPmniTUzg5ARAcGKXdQbRcB2tk5w5PPMYiYhQvqs2YhHMkfV1dyA2O4dOzbA00/fYGweDQ7BrClbueThp8peetAmnFFFkOvDBDm4bsmWsRuHQK883+mQ043xVbiEk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769801093; c=relaxed/simple; bh=LYLjPE5IORq4UG8eIVkHs/P+wZb4Kq6vHRgDcEijYRE=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=OQbY5vwThiKy6Z02pYdaXxsrWFxDkwd15wq1L0Kvvm+9ccK1llg68c9T4TPxv7KmySFTAKa66vkBRuqAWjhemPMAFs/HlxvEgwwYo/e1GFf7EdP2C4N2yDug3oR9Im+NAGS8qOHrAVPEJLEO/a2p/NZzT3q0zxQwMYsur44qP1A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ug7hDnJe; 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="ug7hDnJe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B6064C4CEF7; Fri, 30 Jan 2026 19:24:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769801093; bh=LYLjPE5IORq4UG8eIVkHs/P+wZb4Kq6vHRgDcEijYRE=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=ug7hDnJeSs6BZvkht88WBiDalhscCjJc++vu7r/HArZmhCOZytim1+/ocPfhLZN1Y Q0X5F8+khPlu9t48XJjAClwtraRHhMTKG96rthMccrhjNZUT/shupDngBeDFjmIkjf DT+6nA2ykzH03EteEkTCT6KjHPXhhD3HGzk+2tzU396wP0UDsZeUS3SAogfwVl+hts wZqv72eq++A3lZjIZCBl5Z1Eey4/z1IUR+EQTdIBtuIXBKN79lX3tQsK0Iymzulirh WOMPzm9mLLHOIivm+K/tZSTZpVsSU19N5NikFMSy0XfUqPOGUiS39lPWvALiK8Zfv+ cNt/jJ2mc0KiA== From: "Matthieu Baerts (NGI0)" Date: Fri, 30 Jan 2026 20:24:27 +0100 Subject: [PATCH net-next v2 4/6] mptcp: implement .splice_read Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260130-net-next-mptcp-splice-v2-4-31332ba70d7f@kernel.org> References: <20260130-net-next-mptcp-splice-v2-0-31332ba70d7f@kernel.org> In-Reply-To: <20260130-net-next-mptcp-splice-v2-0-31332ba70d7f@kernel.org> To: Mat Martineau , Geliang Tang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Neal Cardwell , Kuniyuki Iwashima , David Ahern , Shuah Khan Cc: netdev@vger.kernel.org, mptcp@lists.linux.dev, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, "Matthieu Baerts (NGI0)" , Geliang Tang X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=4285; i=matttbe@kernel.org; h=from:subject:message-id; bh=dGLYK6/3afPrBVUkXgyFIvesaiZzdIaNnL/eMHu9RBo=; b=owGbwMvMwCVWo/Th0Gd3rumMp9WSGDJrWUs5V1RqFL+qUtBfeeL1k/NfPqy7UP+a+8BLz6Z5M 30+KR7R6ShlYRDjYpAVU2SRbovMn/m8irfEy88CZg4rE8gQBi5OAZjIjQKG/2nB3L735D5eKdnF 3ruV8/iXQ006++J3TvyhVSf2vE/yHjMjQ98VpmLxrNtTk9TefJZcvPl43PnVfx1fWyiUMCc/eJe 2ngMA X-Developer-Key: i=matttbe@kernel.org; a=openpgp; fpr=E8CB85F76877057A6E27F77AF6B7824F4269A073 From: Geliang Tang This patch implements .splice_read interface of mptcp struct proto_ops as mptcp_splice_read() with reference to tcp_splice_read(). Corresponding to __tcp_splice_read(), __mptcp_splice_read() is defined, invoking mptcp_read_sock() instead of tcp_read_sock(). mptcp_splice_read() is almost the same as tcp_splice_read(), except for sock_rps_record_flow(). Signed-off-by: Geliang Tang Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) --- v2: Fix kdoc warning reported by NIPA --- net/mptcp/protocol.c | 117 +++++++++++++++++++++++++++++++++++++++++++++++= ++++ 1 file changed, 117 insertions(+) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 2071f984da12..9b8c51937eb2 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -4397,6 +4397,121 @@ static int mptcp_read_sock(struct sock *sk, read_de= scriptor_t *desc, return __mptcp_read_sock(sk, desc, recv_actor, false); } =20 +static int __mptcp_splice_read(struct sock *sk, struct tcp_splice_state *t= ss) +{ + /* Store TCP splice context information in read_descriptor_t. */ + read_descriptor_t rd_desc =3D { + .arg.data =3D tss, + .count =3D tss->len, + }; + + return mptcp_read_sock(sk, &rd_desc, tcp_splice_data_recv); +} + +/** + * mptcp_splice_read - splice data from MPTCP socket to a pipe + * @sock: socket to splice from + * @ppos: position (not valid) + * @pipe: pipe to splice to + * @len: number of bytes to splice + * @flags: splice modifier flags + * + * Description: + * Will read pages from given socket and fill them into a pipe. + * + * Return: + * Amount of bytes that have been spliced. + * + **/ +static ssize_t mptcp_splice_read(struct socket *sock, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags) +{ + struct tcp_splice_state tss =3D { + .pipe =3D pipe, + .len =3D len, + .flags =3D flags, + }; + struct sock *sk =3D sock->sk; + ssize_t spliced =3D 0; + int ret =3D 0; + long timeo; + + /* + * We can't seek on a socket input + */ + if (unlikely(*ppos)) + return -ESPIPE; + + lock_sock(sk); + + mptcp_rps_record_subflows(mptcp_sk(sk)); + + timeo =3D sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK); + while (tss.len) { + ret =3D __mptcp_splice_read(sk, &tss); + if (ret < 0) { + break; + } else if (!ret) { + if (spliced) + break; + if (sock_flag(sk, SOCK_DONE)) + break; + if (sk->sk_err) { + ret =3D sock_error(sk); + break; + } + if (sk->sk_shutdown & RCV_SHUTDOWN) + break; + if (sk->sk_state =3D=3D TCP_CLOSE) { + /* + * This occurs when user tries to read + * from never connected socket. + */ + ret =3D -ENOTCONN; + break; + } + if (!timeo) { + ret =3D -EAGAIN; + break; + } + /* if __mptcp_splice_read() got nothing while we have + * an skb in receive queue, we do not want to loop. + * This might happen with URG data. + */ + if (!skb_queue_empty(&sk->sk_receive_queue)) + break; + ret =3D sk_wait_data(sk, &timeo, NULL); + if (ret < 0) + break; + if (signal_pending(current)) { + ret =3D sock_intr_errno(timeo); + break; + } + continue; + } + tss.len -=3D ret; + spliced +=3D ret; + + if (!tss.len || !timeo) + break; + release_sock(sk); + lock_sock(sk); + + if (sk->sk_err || sk->sk_state =3D=3D TCP_CLOSE || + (sk->sk_shutdown & RCV_SHUTDOWN) || + signal_pending(current)) + break; + } + + release_sock(sk); + + if (spliced) + return spliced; + + return ret; +} + static const struct proto_ops mptcp_stream_ops =3D { .family =3D PF_INET, .owner =3D THIS_MODULE, @@ -4418,6 +4533,7 @@ static const struct proto_ops mptcp_stream_ops =3D { .mmap =3D sock_no_mmap, .set_rcvlowat =3D mptcp_set_rcvlowat, .read_sock =3D mptcp_read_sock, + .splice_read =3D mptcp_splice_read, }; =20 static struct inet_protosw mptcp_protosw =3D { @@ -4523,6 +4639,7 @@ static const struct proto_ops mptcp_v6_stream_ops =3D= { #endif .set_rcvlowat =3D mptcp_set_rcvlowat, .read_sock =3D mptcp_read_sock, + .splice_read =3D mptcp_splice_read, }; =20 static struct proto mptcp_v6_prot; --=20 2.51.0