FAILED: patch "[PATCH] selftests: mptcp: connect: fix fallback note due to OoO" failed to apply to 6.1-stable tree

The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 63c643aa7b7287fdbb0167063785f89ece3f000f
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2025112057-untapped-profile-9004@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 63c643aa7b7287fdbb0167063785f89ece3f000f Mon Sep 17 00:00:00 2001
From: "Matthieu Baerts (NGI0)" <[email protected]>
Date: Mon, 10 Nov 2025 19:23:40 +0100
Subject: [PATCH] selftests: mptcp: connect: fix fallback note due to OoO

The "fallback due to TCP OoO" was never printed because the stat_ooo_now variable was checked twice: once in the parent if-statement, and one in the child one. The second condition was then always true then, and the 'else' branch was never taken.

The idea is that when there are more ACK + MP_CAPABLE than expected, the test either fails if there was no out of order packets, or a notice is printed.

index 47ecb5b3836e..9b7b93f8eb0c 100755
@@ -492,7 +492,7 @@ do_transfer()
 				  "than expected (${expect_synrx})"
 		retc=1
 	fi
-	if [ ${stat_ackrx_now_l} -lt ${expect_ackrx} ] && [ ${stat_ooo_now} -eq 0 ]; then
+	if [ ${stat_ackrx_now_l} -lt ${expect_ackrx} ]; then
 		if [ ${stat_ooo_now} -eq 0 ]; then
 			mptcp_lib_pr_fail "lower MPC ACK rx (${stat_ackrx_now_l})" \
 					  "than expected (${expect_ackrx})"

From: "Matthieu Baerts (NGI0)" <[email protected]>

[ Upstream commit 63c643aa7b7287fdbb0167063785f89ece3f000f ]

The "fallback due to TCP OoO" was never printed because the stat_ooo_now variable was checked twice: once in the parent if-statement, and one in the child one. The second condition was then always true then, and the 'else' branch was never taken.

The idea is that when there are more ACK + MP_CAPABLE than expected, the test either fails if there was no out of order packets, or a notice is printed.

---
 tools/testing/selftests/net/mptcp/mptcp_connect.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index dacf4cf2246da..d43eb907d244e 100755
@@ -523,7 +523,7 @@ do_transfer()
 			"${stat_synrx_now_l}" "${expect_synrx}" 1>&2
 		retc=1
 	fi
-	if [ ${stat_ackrx_now_l} -lt ${expect_ackrx} -a ${stat_ooo_now} -eq 0 ]; then
+	if [ ${stat_ackrx_now_l} -lt ${expect_ackrx} ]; then
 		if [ ${stat_ooo_now} -eq 0 ]; then
 			printf "[ FAIL ] lower MPC ACK rx (%d) than expected (%d)\n" \
 				"${stat_ackrx_now_l}" "${expect_ackrx}" 1>&2

2.51.0