From: Geliang Tang <tanggeliang@kylinos.cn>
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() and __mptcp_move_skbs().
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
net/mptcp/protocol.c | 94 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 94 insertions(+)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 6574f82d59d1..701295f6ae1b 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -4091,6 +4091,98 @@ static int mptcp_read_sock(struct sock *sk, read_descriptor_t *desc,
return copied;
}
+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, err;
+ long timeo;
+
+ /*
+ * We can't seek on a socket input
+ */
+ if (unlikely(*ppos))
+ return -ESPIPE;
+
+ lock_sock(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) {
+ if (spliced)
+ break;
+ err = tcp_recv_should_stop(sk, timeo);
+ if (err < 0) {
+ if (err == -ESHUTDOWN) {
+ if (__mptcp_move_skbs(sk))
+ continue;
+ break;
+ }
+ 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;
+ ret = sk_wait_data(sk, &timeo, NULL);
+ if (ret < 0)
+ break;
+ continue;
+ }
+ tss.len -= ret;
+ spliced += ret;
+
+ if (!tss.len)
+ break;
+
+ 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,
@@ -4112,6 +4204,7 @@ 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 = {
@@ -4217,6 +4310,7 @@ 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;
--
2.48.1On Tue, 2 Sep 2025, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@kylinos.cn>
>
> 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() and __mptcp_move_skbs().
>
Hi Geliang -
Please take a look at the recent addition of mptcp_rps_record_subflows()!
This should be added to mptcp_splice_read.
- Mat
> Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
> ---
> net/mptcp/protocol.c | 94 ++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 94 insertions(+)
>
> diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
> index 6574f82d59d1..701295f6ae1b 100644
> --- a/net/mptcp/protocol.c
> +++ b/net/mptcp/protocol.c
> @@ -4091,6 +4091,98 @@ static int mptcp_read_sock(struct sock *sk, read_descriptor_t *desc,
> return copied;
> }
>
> +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, err;
> + long timeo;
> +
> + /*
> + * We can't seek on a socket input
> + */
> + if (unlikely(*ppos))
> + return -ESPIPE;
> +
> + lock_sock(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) {
> + if (spliced)
> + break;
> + err = tcp_recv_should_stop(sk, timeo);
> + if (err < 0) {
> + if (err == -ESHUTDOWN) {
> + if (__mptcp_move_skbs(sk))
> + continue;
> + break;
> + }
> + 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;
> + ret = sk_wait_data(sk, &timeo, NULL);
> + if (ret < 0)
> + break;
> + continue;
> + }
> + tss.len -= ret;
> + spliced += ret;
> +
> + if (!tss.len)
> + break;
> +
> + 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,
> @@ -4112,6 +4204,7 @@ 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 = {
> @@ -4217,6 +4310,7 @@ 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;
> --
> 2.48.1
>
>
>
On Fri, 2025-09-12 at 16:41 -0700, Mat Martineau wrote:
> On Tue, 2 Sep 2025, Geliang Tang wrote:
>
> > From: Geliang Tang <tanggeliang@kylinos.cn>
> >
> > 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() and __mptcp_move_skbs().
> >
>
> Hi Geliang -
>
> Please take a look at the recent addition of
> mptcp_rps_record_subflows()!
> This should be added to mptcp_splice_read.
Yes, indeed. It was included in v11.
Thanks,
-Geliang
>
> - Mat
>
>
> > Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
> > ---
> > net/mptcp/protocol.c | 94
> > ++++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 94 insertions(+)
> >
> > diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
> > index 6574f82d59d1..701295f6ae1b 100644
> > --- a/net/mptcp/protocol.c
> > +++ b/net/mptcp/protocol.c
> > @@ -4091,6 +4091,98 @@ static int mptcp_read_sock(struct sock *sk,
> > read_descriptor_t *desc,
> > return copied;
> > }
> >
> > +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, err;
> > + long timeo;
> > +
> > + /*
> > + * We can't seek on a socket input
> > + */
> > + if (unlikely(*ppos))
> > + return -ESPIPE;
> > +
> > + lock_sock(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) {
> > + if (spliced)
> > + break;
> > + err = tcp_recv_should_stop(sk, timeo);
> > + if (err < 0) {
> > + if (err == -ESHUTDOWN) {
> > + if (__mptcp_move_skbs(sk))
> > + continue;
> > + break;
> > + }
> > + 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;
> > + ret = sk_wait_data(sk, &timeo, NULL);
> > + if (ret < 0)
> > + break;
> > + continue;
> > + }
> > + tss.len -= ret;
> > + spliced += ret;
> > +
> > + if (!tss.len)
> > + break;
> > +
> > + 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,
> > @@ -4112,6 +4204,7 @@ 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 = {
> > @@ -4217,6 +4310,7 @@ 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;
> > --
> > 2.48.1
> >
> >
> >
© 2016 - 2025 Red Hat, Inc.