From mboxrd@z Thu Jan 1 00:00:00 1970 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 D27EF31A80E for ; Sat, 6 Dec 2025 00:22:01 +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=1764980521; cv=none; b=GlHcwCW83vMyb0kGEJsJFKQirgHmuHW7Pjnik/bBUT46J2l6/RNgsug0IaixB7JfCXX1EvADw/2BhLDYBgopW6GOvaZQjpC0Sy+gSVvZ3ZhH7hJoaj6xSo+o9LhF0nRqAE9ivKCrwu49p7rILPQBhLUX0T42iwnLkO63RXz7q0g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764980521; c=relaxed/simple; bh=kKzZ7Rp9SGQ/8qVldDp0KMkdPSUAFMRFC47uaYVBRhY=; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type; b=rOLTUbXtxcTSaX4U5fiV3WiiF1fUk7kbK/R/I48IZyr+NAzMs0z+fPqzaTqJBTE3rOiBtfYGa0VlvHizBA/gHZkNSAAUjHIzmBcvljxxAJpiZRz534aynbgufhbeEkklAedZ9Fu7IOpgWtnqj0XyNUBk1MgCQCoysetk28Uv6eE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=R/dXohQF; 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="R/dXohQF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A8BC7C4CEF1; Sat, 6 Dec 2025 00:22:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764980521; bh=kKzZ7Rp9SGQ/8qVldDp0KMkdPSUAFMRFC47uaYVBRhY=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=R/dXohQFlAzAivvi7UPheo4u1Wp4LRB0E4QFO0R1aNA25q5ZXyghXlieUajgsnbuV v5CEuPwUjvmBMEydPS3ojvvb2mzpXuZLMFzL/ug+glb8TJiEXM7Fb8EC+sGX44SZsF quHMvVHydTrO7I7vPapSgf78QWFPTDohxcD6ZiJdwmg4orNVZQrXL5zC28fSXj7v8b SrX4wwFpyYfPuIoFCjWP0kt3wy+kurdxvDozrqV9TOZ3/dToNjjMeC6oyGY2F34Ygq XiNUcUgFoCcEZD0Oa8pS5vuqCQZtAGj05KyQVwz/+cv7q6inUXq/GjsrMKBNMJTc8G c0Qiziw0ldVcA== Date: Fri, 5 Dec 2025 16:22:01 -0800 (PST) From: Mat Martineau To: Geliang Tang cc: mptcp@lists.linux.dev, Geliang Tang Subject: Re: [PATCH mptcp-next v14 6/8] mptcp: implement .splice_read In-Reply-To: Message-ID: <088efdb2-4f2b-3c37-ce09-19a855f4f08f@kernel.org> References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset=US-ASCII On Mon, 24 Nov 2025, Geliang Tang wrote: > 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 | 96 ++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 96 insertions(+) > > diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c > index 9302b372910e..abd0f44ad63f 100644 > --- a/net/mptcp/protocol.c > +++ b/net/mptcp/protocol.c > @@ -4355,6 +4355,100 @@ static int mptcp_read_sock(struct sock *sk, read_descriptor_t *desc, > return __mptcp_read_sock(sk, desc, recv_actor, false); > } > > +static int __mptcp_splice_read(struct sock *sk, struct tcp_splice_state *tss) > +{ > + /* Store TCP splice context information in read_descriptor_t. */ > + read_descriptor_t rd_desc = { > + .arg.data = tss, > + .count = 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. > + * > + **/ > +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 = { > + .pipe = pipe, > + .len = len, > + .flags = flags, > + }; > + struct sock *sk = sock->sk; > + ssize_t spliced = 0; > + int ret = 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 = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK); > + while (tss.len) { > + ret = __mptcp_splice_read(sk, &tss); > + if (ret < 0) { > + break; > + } else if (!ret) { > + int err; > + > + if (spliced) > + break; > + err = tcp_recv_should_stop(sk, timeo); > + if (err < 0) { > + if (err != -ESHUTDOWN) > + ret = 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; Hi Geliang - This queue could also be non-empty due to the length limit in patch 2. Maybe another reason to remove that length limit. - Mat > + ret = sk_wait_data(sk, &timeo, NULL); > + if (ret < 0) > + break; > + continue; > + } > + tss.len -= ret; > + spliced += 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 = { > .family = PF_INET, > .owner = THIS_MODULE, > @@ -4376,6 +4470,7 @@ static const struct proto_ops mptcp_stream_ops = { > .mmap = sock_no_mmap, > .set_rcvlowat = mptcp_set_rcvlowat, > .read_sock = mptcp_read_sock, > + .splice_read = mptcp_splice_read, > }; > > static struct inet_protosw mptcp_protosw = { > @@ -4481,6 +4576,7 @@ static const struct proto_ops mptcp_v6_stream_ops = { > #endif > .set_rcvlowat = mptcp_set_rcvlowat, > .read_sock = mptcp_read_sock, > + .splice_read = mptcp_splice_read, > }; > > static struct proto mptcp_v6_prot; > -- > 2.43.0 > > >