From nobody Fri Oct 31 23:22:29 2025 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 D5D8B219A7D for ; Thu, 23 Oct 2025 05:57:12 +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=1761199032; cv=none; b=VU7sjDCZciubk+QKQHW/AWZqoX3ZMQMEUDh72rQOZatXduLcIKDHjiGgYHpOl0WNYaholiEk7n05vYiUQ3UhloMMjtW2RCUMA5CO7jWCSRH3fCGrAfrJEvjca8n8DJf3PDqJ9GzkUaGc2eHXOBr0zHXVwsYeC3d6H41eycvcuRw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761199032; c=relaxed/simple; bh=rAGUhChJa/qTPr6/TTSMvqLm774ReaCbFwtUBY4DhDk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WM1H3ee0xrq4GtMokC3UWE1TYu26dssNulbt3lkz1IUVqNxm3+RngxqHWMZpqTIEzUpQFeNo8h9pIL2oTjEmRfGgl/gIYu8YyZvK9OmiD3b0rHU1oEsr+BD+jCAdaGyj+615+HarSagneDOsLcPnjNaZm1dg0Xy9VxndTLGmRxI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=N40gnNN4; 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="N40gnNN4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D180C4CEFD; Thu, 23 Oct 2025 05:57:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761199032; bh=rAGUhChJa/qTPr6/TTSMvqLm774ReaCbFwtUBY4DhDk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N40gnNN4rw1t74c7GXnh2UMRYoTTb3TAH4B3VQwzHepNeXRYPDz/fAWX90pExYJrE naN+yhY6Keyym8fjOoDnN/1kXp/G4VQiSTXLAviJpKUZ+LOsoEJn3ts6ehEZTPIblp q5gmDlaIM9W6HmjxrUCGBUVkkAglRWqcca4ZSa/VTyGWbNTMbCn8dC4UursKyELX4u EjwM3HMxRPVuLgAxU1Da/EcTw5k8oNf/CwTGjRb8KD47r4/Ba0UKMLh+zjGM9/++1E ID45AK0KVxOe4wz4PGMqYMY88KVX1Q49Rcn3r+SbySmcHYtABm3PWncFMR5P8wgrru ewSpEXUhAgxQw== From: Geliang Tang To: mptcp@lists.linux.dev, hare@kernel.org Cc: Geliang Tang Subject: [PATCH mptcp-next v13 6/8] mptcp: implement .splice_read Date: Thu, 23 Oct 2025 13:56:49 +0800 Message-ID: <6388be6c73553a40fc8a60aa020cea0c10b40005.1761198660.git.geliang@kernel.org> X-Mailer: git-send-email 2.43.0 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 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 --- net/mptcp/protocol.c | 109 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 109 insertions(+) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 1955717e7dfc..91d3bf5e6a75 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -4245,6 +4245,113 @@ static int mptcp_read_sock(struct sock *sk, read_de= scriptor_t *desc, return copied; } =20 +static int mptcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_bu= ff *skb, + unsigned int offset, size_t len) +{ + struct tcp_splice_state *tss =3D rd_desc->arg.data; + int ret; + + ret =3D skb_splice_bits(skb, skb->sk, offset, tss->pipe, + min(rd_desc->count, len), tss->flags); + if (ret > 0) + rd_desc->count -=3D ret; + return ret; +} + +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, mptcp_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. + * + **/ +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) { + int err; + + if (spliced) + break; + err =3D tcp_recv_should_stop(sk, timeo); + if (err < 0) { + if (err !=3D -ESHUTDOWN) + ret =3D err; + 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; + continue; + } + tss.len -=3D ret; + spliced +=3D ret; + + if (!tss.len || !timeo) + break; + release_sock(sk); + lock_sock(sk); + + if (tcp_recv_should_stop(sk, timeo)) + 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, @@ -4266,6 +4373,7 @@ 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 { @@ -4371,6 +4479,7 @@ 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 2.43.0