This patch defined the default packet scheduler mptcp_sched_default,
registered it in mptcp_sched_init().

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 net/mptcp/protocol.c |  2 +-
 net/mptcp/protocol.h |  1 +
 net/mptcp/sched.c    | 10 ++++++++++
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index b1d7c8b0c112..81b77ade9511 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1424,7 +1424,7 @@ 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;
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 3258b740c8ee..46ac5b4528d5 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -614,6 +614,7 @@ int mptcp_register_scheduler(const struct net *net,
 			     struct mptcp_sched_ops *sched);
 void mptcp_unregister_scheduler(const struct net *net,
 				struct mptcp_sched_ops *sched);
+struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk);
 void mptcp_sched_init(void);
 
 static inline bool __mptcp_subflow_active(struct mptcp_subflow_context *subflow)
diff --git a/net/mptcp/sched.c b/net/mptcp/sched.c
index 3798a5cefeb6..f6ace8cfe865 100644
--- a/net/mptcp/sched.c
+++ b/net/mptcp/sched.c
@@ -23,6 +23,12 @@ struct sched_pernet {
 	struct list_head	sched_list;
 };
 
+static struct mptcp_sched_ops mptcp_sched_default = {
+	.get_subflow    = mptcp_subflow_get_send,
+	.name           = "default",
+	.owner          = THIS_MODULE,
+};
+
 static struct sched_pernet *sched_get_pernet(const struct net *net)
 {
 	return net_generic(net, sched_pernet_id);
@@ -70,6 +76,9 @@ void mptcp_unregister_scheduler(const struct net *net,
 {
 	struct sched_pernet *pernet = sched_get_pernet(net);
 
+	if (sched == &mptcp_sched_default)
+		return;
+
 	spin_lock(&pernet->lock);
 	list_del_rcu(&sched->list);
 	spin_unlock(&pernet->lock);
@@ -111,4 +120,5 @@ void mptcp_sched_init(void)
 {
 	if (register_pernet_subsys(&mptcp_sched_pernet_ops) < 0)
 		panic("Failed to register MPTCP sched pernet subsystem.\n");
+	mptcp_register_scheduler(&init_net, &mptcp_sched_default);
 }
-- 
2.34.1