Merge branch 'mptcp-fixes-for-5-19'

Mat Martineau says:

====================
mptcp: Fixes for 5.19

Several categories of fixes from the mptcp tree:

Patches 1-3 are fixes related to MP_FAIL and FASTCLOSE, to make sure
MIBs are accurate, and to handle MP_FAIL transmission and responses at
the correct times. sk_timer conflicts are also resolved.

Patches 4 and 6 handle two separate race conditions, one at socket
shutdown and one with unaccepted subflows.

Patch 5 makes sure read operations are not blocked during fallback to
TCP.

Patch 7 improves the diag selftest, which were incorrectly failing on
slow machines (like the VMs used for CI testing).

Patch 8 avoids possible symbol redefinition errors in the userspace
mptcp.h file.

Patch 9 fixes a selftest build issue with gcc 12.
====================

Link: https://lore.kernel.org/r/20220628010243.166605-1-mathew.j.martineau@linux.intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 4 insertions, 6 deletions

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 59a85220edc9..45e2a48397b9 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -299,23 +299,21 @@ 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);
-	struct sock *s = (struct sock *)msk;
 
 	pr_debug("fail_seq=%llu", fail_seq);
 
 	if (!READ_ONCE(msk->allow_infinite_fallback))
 		return;
 
-	if (!READ_ONCE(subflow->mp_fail_response_expect)) {
+	if (!subflow->fail_tout) {
 		pr_debug("send MP_FAIL response and infinite map");
 
 		subflow->send_mp_fail = 1;
-		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFAILTX);
 		subflow->send_infinite_map = 1;
-	} else if (!sock_flag(sk, SOCK_DEAD)) {
+		tcp_send_ack(sk);
+	} else {
 		pr_debug("MP_FAIL response received");
-
-		sk_stop_timer(s, &s->sk_timer);
+		WRITE_ONCE(subflow->fail_tout, 0);
 	}
 }