[PATCH 5.15.y 2/6] mptcp: fix error mibs accounting

["Matthieu Baerts (NGI0)" <matttbe@kernel.org>]

From: Paolo Abeni <pabeni@redhat.com>

commit 0c1f78a49af721490a5ad70b73e8b4d382465dae upstream.

The current accounting for MP_FAIL and FASTCLOSE is not very
accurate: both can be increased even when the related option is
not really sent. Move the accounting into the correct place.

Fixes: eb7f33654dc1 ("mptcp: add the mibs for MP_FAIL")
Fixes: 1e75629cb964 ("mptcp: add the mibs for MP_FASTCLOSE")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ Conflicts, because commit f284c0c77321 ("mptcp: implement fastclose
  xmit path") is not in this version. That's OK, the new helper added
  by this commit doesn't need to be modified. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 net/mptcp/options.c | 1 +
 net/mptcp/subflow.c | 4 +---
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index d1443c5732c8..501c818bf7dc 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -793,6 +793,7 @@ static bool mptcp_established_options_mp_fail(struct sock *sk,
 	opts->fail_seq = subflow->map_seq;
 
 	pr_debug("MP_FAIL fail_seq=%llu\n", opts->fail_seq);
+	MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFAILTX);
 
 	return true;
 }
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 2bf7f65b0afe..6a7c48397e3d 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -963,10 +963,8 @@ static enum mapping_status validate_data_csum(struct sock *ssk, struct sk_buff *
 				 subflow->map_data_csum);
 	if (unlikely(csum)) {
 		MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DATACSUMERR);
-		if (subflow->mp_join || subflow->valid_csum_seen) {
+		if (subflow->mp_join || subflow->valid_csum_seen)
 			subflow->send_mp_fail = 1;
-			MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_MPFAILTX);
-		}
 		return subflow->mp_join ? MAPPING_INVALID : MAPPING_DUMMY;
 	}
 
-- 
2.50.0