From: Geliang Tang <geliang.tang@suse.com>

This patch defines two packet scheduler wrappers mptcp_sched_get_send()
and mptcp_sched_get_retrans(), invoke get_subflow() of msk->sched in
them.

Set data->reinject to true in mptcp_sched_get_retrans(), set it false in
mptcp_sched_get_send().

If msk->sched is NULL, use default functions mptcp_subflow_get_send()
and mptcp_subflow_get_retrans() to send data.

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
---
 net/mptcp/protocol.c |  4 ++--
 net/mptcp/protocol.h |  4 ++++
 net/mptcp/sched.c    | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 54 insertions(+), 2 deletions(-)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 54a3eccfa731..9cd172d2c8d6 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1366,7 +1366,7 @@ bool mptcp_subflow_active(struct mptcp_subflow_context *subflow)
  * returns the subflow that will transmit the next DSS
  * additionally updates the rtx timeout
  */
-static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
+struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
 {
 	struct subflow_send_info send_info[SSK_MODE_MAX];
 	struct mptcp_subflow_context *subflow;
@@ -2204,7 +2204,7 @@ static void mptcp_timeout_timer(struct timer_list *t)
  *
  * A backup subflow is returned only if that is the only kind available.
  */
-static struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk)
+struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk)
 {
 	struct sock *backup = NULL, *pick = NULL;
 	struct mptcp_subflow_context *subflow;
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index e7523a40132f..78562f695c46 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -666,6 +666,10 @@ int mptcp_init_sched(struct mptcp_sock *msk,
 void mptcp_release_sched(struct mptcp_sock *msk);
 void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subflow,
 				 bool scheduled);
+struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk);
+struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk);
+int mptcp_sched_get_send(struct mptcp_sock *msk);
+int mptcp_sched_get_retrans(struct mptcp_sock *msk);
 
 static inline bool __tcp_can_send(const struct sock *ssk)
 {
diff --git a/net/mptcp/sched.c b/net/mptcp/sched.c
index d295b92a5789..884606686cfe 100644
--- a/net/mptcp/sched.c
+++ b/net/mptcp/sched.c
@@ -93,3 +93,51 @@ void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subflow,
 {
 	WRITE_ONCE(subflow->scheduled, scheduled);
 }
+
+int mptcp_sched_get_send(struct mptcp_sock *msk)
+{
+	struct mptcp_subflow_context *subflow;
+	struct mptcp_sched_data data;
+
+	mptcp_for_each_subflow(msk, subflow) {
+		if (READ_ONCE(subflow->scheduled))
+			return 0;
+	}
+
+	if (!msk->sched) {
+		struct sock *ssk;
+
+		ssk = mptcp_subflow_get_send(msk);
+		if (!ssk)
+			return -EINVAL;
+		mptcp_subflow_set_scheduled(mptcp_subflow_ctx(ssk), true);
+		return 0;
+	}
+
+	data.reinject = false;
+	return msk->sched->get_subflow(msk, &data);
+}
+
+int mptcp_sched_get_retrans(struct mptcp_sock *msk)
+{
+	struct mptcp_subflow_context *subflow;
+	struct mptcp_sched_data data;
+
+	mptcp_for_each_subflow(msk, subflow) {
+		if (READ_ONCE(subflow->scheduled))
+			return 0;
+	}
+
+	if (!msk->sched) {
+		struct sock *ssk;
+
+		ssk = mptcp_subflow_get_retrans(msk);
+		if (!ssk)
+			return -EINVAL;
+		mptcp_subflow_set_scheduled(mptcp_subflow_ctx(ssk), true);
+		return 0;
+	}
+
+	data.reinject = true;
+	return msk->sched->get_subflow(msk, &data);
+}

-- 
2.41.0