mptcp: add get_subflow wrappers

This patch defines two new wrappers mptcp_sched_get_send() and mptcp_sched_get_retrans(), invoke get_subflow() of msk->sched in them. Set the subflow pointers array in struct mptcp_sched_data before invoking get_subflow(), then it can be used in get_subflow() in the BPF contexts. Check the subflow scheduled flags to test which subflow or subflows are picked by the scheduler. Move sock_owned_by_me() and the fallback check code from mptcp_subflow_get_send/retrans() into the wrappers. Acked-by: Paolo Abeni <[email protected]> Reviewed-by: Mat Martineau <[email protected]> Signed-off-by: Geliang Tang <[email protected]>
intel-lab-lkp · Oct 24, 2022 · 8ae8437 · 8ae8437
1 parent 8db63fc
commit 8ae8437
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Showing 3 changed files with 88 additions and 16 deletions.
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
@@ -1406,7 +1406,7 @@ 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;
@@ -1417,15 +1417,6 @@ static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
 	u64 linger_time;
 	long tout = 0;
 
-	sock_owned_by_me(sk);
-
-	if (__mptcp_check_fallback(msk)) {
-		if (!msk->first)
-			return NULL;
-		return __tcp_can_send(msk->first) &&
-		       sk_stream_memory_free(msk->first) ? msk->first : NULL;
-	}
-
 	/* re-use last subflow, if the burst allow that */
 	if (msk->last_snd && msk->snd_burst > 0 &&
 	    sk_stream_memory_free(msk->last_snd) &&
@@ -2219,17 +2210,12 @@ 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;
 	int min_stale_count = INT_MAX;
 
-	sock_owned_by_me((const struct sock *)msk);
-
-	if (__mptcp_check_fallback(msk))
-		return NULL;
-
 	mptcp_for_each_subflow(msk, subflow) {
 		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 

diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
@@ -641,6 +641,10 @@ 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
@@ -93,3 +93,85 @@ void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subflow,
 {
 	WRITE_ONCE(subflow->scheduled, scheduled);
 }
+
+static int mptcp_sched_data_init(struct mptcp_sock *msk, bool reinject,
+				 struct mptcp_sched_data *data)
+{
+	struct mptcp_subflow_context *subflow;
+	int i = 0;
+
+	data->reinject = reinject;
+
+	mptcp_for_each_subflow(msk, subflow) {
+		if (i == MPTCP_SUBFLOWS_MAX) {
+			pr_warn_once("too many subflows");
+			break;
+		}
+		mptcp_subflow_set_scheduled(subflow, false);
+		data->contexts[i++] = subflow;
+	}
+
+	for (; i < MPTCP_SUBFLOWS_MAX; i++)
+		data->contexts[i] = NULL;
+
+	msk->snd_burst = 0;
+
+	return 0;
+}
+
+int mptcp_sched_get_send(struct mptcp_sock *msk)
+{
+	struct mptcp_sched_data data;
+	struct sock *ssk = NULL;
+
+	sock_owned_by_me((const struct sock *)msk);
+
+	/* the following check is moved out of mptcp_subflow_get_send */
+	if (__mptcp_check_fallback(msk)) {
+		if (msk->first &&
+		    __tcp_can_send(msk->first) &&
+		    sk_stream_memory_free(msk->first)) {
+			mptcp_subflow_set_scheduled(mptcp_subflow_ctx(msk->first), true);
+			return 0;
+		}
+		return -EINVAL;
+	}
+
+	if (!msk->sched) {
+		ssk = mptcp_subflow_get_send(msk);
+		if (!ssk)
+			return -EINVAL;
+		mptcp_subflow_set_scheduled(mptcp_subflow_ctx(ssk), true);
+		return 0;
+	}
+
+	mptcp_sched_data_init(msk, false, &data);
+	msk->sched->get_subflow(msk, &data);
+
+	return 0;
+}
+
+int mptcp_sched_get_retrans(struct mptcp_sock *msk)
+{
+	struct mptcp_sched_data data;
+	struct sock *ssk = NULL;
+
+	sock_owned_by_me((const struct sock *)msk);
+
+	/* the following check is moved out of mptcp_subflow_get_retrans */
+	if (__mptcp_check_fallback(msk))
+		return -EINVAL;
+
+	if (!msk->sched) {
+		ssk = mptcp_subflow_get_retrans(msk);
+		if (!ssk)
+			return -EINVAL;
+		mptcp_subflow_set_scheduled(mptcp_subflow_ctx(ssk), true);
+		return 0;
+	}
+
+	mptcp_sched_data_init(msk, true, &data);
+	msk->sched->get_subflow(msk, &data);
+
+	return 0;
+}