This patch adds the multiple subflows support for __mptcp_push_pending().
Use mptcp_sched_get_send() wrapper instead of mptcp_subflow_get_send() in
it.

Check the subflow scheduled flags to test which subflow or subflows are
picked by the scheduler, use them to send data.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 net/mptcp/protocol.c | 33 +++++++++++++++++++++------------
 1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 29905214103e..fdb879e09a32 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1561,22 +1561,31 @@ static int __subflow_push_pending(struct sock *sk, struct sock *ssk,
 void __mptcp_push_pending(struct sock *sk, unsigned int flags)
 {
 	struct mptcp_sock *msk = mptcp_sk(sk);
-	struct mptcp_sendmsg_info info = {
-				.flags = flags,
-	};
-	struct sock *ssk;
 	int ret = 0;
 
 again:
-	while (mptcp_send_head(sk) && (ssk = mptcp_subflow_get_send(msk))) {
-		lock_sock(ssk);
-		ret = __subflow_push_pending(sk, ssk, &info);
-		release_sock(ssk);
+	while (mptcp_send_head(sk) && !mptcp_sched_get_send(msk)) {
+		struct mptcp_subflow_context *subflow;
+		struct mptcp_sendmsg_info info = {
+			.flags = flags,
+		};
 
-		if (ret <= 0) {
-			if (ret == -EAGAIN)
-				goto again;
-			goto out;
+		mptcp_for_each_subflow(msk, subflow) {
+			if (READ_ONCE(subflow->scheduled)) {
+				struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
+
+				lock_sock(ssk);
+				ret = __subflow_push_pending(sk, ssk, &info);
+				release_sock(ssk);
+
+				if (ret <= 0) {
+					if (ret == -EAGAIN)
+						goto again;
+					goto out;
+				}
+				msk->last_snd = ssk;
+				mptcp_subflow_set_scheduled(subflow, false);
+			}
 		}
 	}
 
-- 
2.35.3