Merge branch 'mptcp-close-subflow-when-receiving-tcp-fin-and-misc'

Matthieu Baerts says:

====================
mptcp: close subflow when receiving TCP+FIN and misc.

Here are different fixes:

Patch 1 closes the subflow after having received a FIN, instead
of leaving it half-closed until the end of the MPTCP connection.
A fix for v5.12.

Patch 2 validates the previous patch.

Patch 3 is a fix for a recent fix to check both directions for the
backup flag. It can follow the 'Fixes' commit and be backported up
to v5.7.

Patch 4 adds a missing \n at the end of pr_debug(), causing debug
messages to be displayed with a delay, which confuses the debugger.
A fix for v5.6.
====================

Link: https://patch.msgid.link/20240826-net-mptcp-close-extra-sf-fin-v1-0-905199fe1172@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 14 insertions, 14 deletions

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 3e6e0f5510bb..3f8dbde243f1 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -19,7 +19,7 @@ int mptcp_pm_announce_addr(struct mptcp_sock *msk,
 {
 	u8 add_addr = READ_ONCE(msk->pm.addr_signal);
 
-	pr_debug("msk=%p, local_id=%d, echo=%d", msk, addr->id, echo);
+	pr_debug("msk=%p, local_id=%d, echo=%d\n", msk, addr->id, echo);
 
 	lockdep_assert_held(&msk->pm.lock);
 
@@ -45,7 +45,7 @@ int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_
 {
 	u8 rm_addr = READ_ONCE(msk->pm.addr_signal);
 
-	pr_debug("msk=%p, rm_list_nr=%d", msk, rm_list->nr);
+	pr_debug("msk=%p, rm_list_nr=%d\n", msk, rm_list->nr);
 
 	if (rm_addr) {
 		MPTCP_ADD_STATS(sock_net((struct sock *)msk),
@@ -66,7 +66,7 @@ void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int
 {
 	struct mptcp_pm_data *pm = &msk->pm;
 
-	pr_debug("msk=%p, token=%u side=%d", msk, READ_ONCE(msk->token), server_side);
+	pr_debug("msk=%p, token=%u side=%d\n", msk, READ_ONCE(msk->token), server_side);
 
 	WRITE_ONCE(pm->server_side, server_side);
 	mptcp_event(MPTCP_EVENT_CREATED, msk, ssk, GFP_ATOMIC);
@@ -90,7 +90,7 @@ bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
 
 	subflows_max = mptcp_pm_get_subflows_max(msk);
 
-	pr_debug("msk=%p subflows=%d max=%d allow=%d", msk, pm->subflows,
+	pr_debug("msk=%p subflows=%d max=%d allow=%d\n", msk, pm->subflows,
 		 subflows_max, READ_ONCE(pm->accept_subflow));
 
 	/* try to avoid acquiring the lock below */
@@ -114,7 +114,7 @@ bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
 static bool mptcp_pm_schedule_work(struct mptcp_sock *msk,
 				   enum mptcp_pm_status new_status)
 {
-	pr_debug("msk=%p status=%x new=%lx", msk, msk->pm.status,
+	pr_debug("msk=%p status=%x new=%lx\n", msk, msk->pm.status,
 		 BIT(new_status));
 	if (msk->pm.status & BIT(new_status))
 		return false;
@@ -129,7 +129,7 @@ void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk)
 	struct mptcp_pm_data *pm = &msk->pm;
 	bool announce = false;
 
-	pr_debug("msk=%p", msk);
+	pr_debug("msk=%p\n", msk);
 
 	spin_lock_bh(&pm->lock);
 
@@ -153,14 +153,14 @@ void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk)
 
 void mptcp_pm_connection_closed(struct mptcp_sock *msk)
 {
-	pr_debug("msk=%p", msk);
+	pr_debug("msk=%p\n", msk);
 }
 
 void mptcp_pm_subflow_established(struct mptcp_sock *msk)
 {
 	struct mptcp_pm_data *pm = &msk->pm;
 
-	pr_debug("msk=%p", msk);
+	pr_debug("msk=%p\n", msk);
 
 	if (!READ_ONCE(pm->work_pending))
 		return;
@@ -212,7 +212,7 @@ void mptcp_pm_add_addr_received(const struct sock *ssk,
 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
 	struct mptcp_pm_data *pm = &msk->pm;
 
-	pr_debug("msk=%p remote_id=%d accept=%d", msk, addr->id,
+	pr_debug("msk=%p remote_id=%d accept=%d\n", msk, addr->id,
 		 READ_ONCE(pm->accept_addr));
 
 	mptcp_event_addr_announced(ssk, addr);
@@ -243,7 +243,7 @@ void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
 {
 	struct mptcp_pm_data *pm = &msk->pm;
 
-	pr_debug("msk=%p", msk);
+	pr_debug("msk=%p\n", msk);
 
 	spin_lock_bh(&pm->lock);
 
@@ -267,7 +267,7 @@ void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
 	struct mptcp_pm_data *pm = &msk->pm;
 	u8 i;
 
-	pr_debug("msk=%p remote_ids_nr=%d", msk, rm_list->nr);
+	pr_debug("msk=%p remote_ids_nr=%d\n", msk, rm_list->nr);
 
 	for (i = 0; i < rm_list->nr; i++)
 		mptcp_event_addr_removed(msk, rm_list->ids[i]);
@@ -299,19 +299,19 @@ void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq)
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
 
-	pr_debug("fail_seq=%llu", fail_seq);
+	pr_debug("fail_seq=%llu\n", fail_seq);
 
 	if (!READ_ONCE(msk->allow_infinite_fallback))
 		return;
 
 	if (!subflow->fail_tout) {
-		pr_debug("send MP_FAIL response and infinite map");
+		pr_debug("send MP_FAIL response and infinite map\n");
 
 		subflow->send_mp_fail = 1;
 		subflow->send_infinite_map = 1;
 		tcp_send_ack(sk);
 	} else {
-		pr_debug("MP_FAIL response received");
+		pr_debug("MP_FAIL response received\n");
 		WRITE_ONCE(subflow->fail_tout, 0);
 	}
 }