stress2: add two new unionfs test scenarios

These exercise lookup traversal from tmpfs into unionfs, which is
useful because, unlike UFS, tmpfs does not allow recursion on its vnode
locks by default.

unionfs22.sh exercises these lookups with a normal unionfs mount, while
unionfs23.sh uses '-o below' for the unionfs mount and reproduces the
panic described in PR 298201.

Reviewed by:	kib, markj, pho
Tested by:	pho
Differential Revision:	https://reviews.freebsd.org/D59494

tools/test/stress2/misc/unionfs22.sh

@@ -0,0 +1,77 @@
+#!/bin/sh
+
+#
+# Copyright (c) 2024 Peter Holm <[email protected]>
+# Copyright (c) 2026 Jason Harmening <[email protected]>
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+
+# unionfs(4) test
+# Variation of unionfs7.sh, but with unionfs lookup
+# traversing a tmpfs mount.
+# No issues seen with this test.
+
+[ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
+. ../default.cfg
+
+mp1=/mnt$mdstart
+mp2=/mnt$((mdstart + 1))
+mp3=$mp2/unionfs
+
+mkdir -p $mp1 $mp2
+set -e
+for i in $mp1 $mp2; do
+	mount | grep -q "on $i " && umount -f $i
+done
+
+mount -o size=4g -t tmpfs dummy $mp1
+mount -o size=4g -t tmpfs dummy $mp2
+mkdir -p $mp3
+
+mount -t unionfs -o noatime $mp1 $mp3
+set +e
+export 'INODES=100000'
+
+export CTRLDIR=$mp3/stressX.control
+export INCARNATIONS=10
+export LOAD=80
+export RUNDIR=$mp3/stressX
+export runRUNTIME=5m
+export rwLOAD=80
+export symlinkLOAD=80
+
+export TESTPROGS="
+unionfs/stress2/testcases/lockf2/lockf2
+unionfs/stress2/testcases/symlink/symlink
+unionfs/stress2/testcases/openat/openat
+unionfs/stress2/testcases/rw/rw
+unionfs/stress2/testcases/fts/fts
+unionfs/stress2/testcases/link/link
+unionfs/stress2/testcases/lockf/lockf
+unionfs/stress2/testcases/creat/creat
+unionfs/stress2/testcases/mkdir/mkdir
+unionfs/stress2/testcases/rename/rename
+unionfs/stress2/testcases/mkfifo/mkfifo
+unionfs/stress2/testcases/dirnprename/dirnprename
+unionfs/stress2/testcases/dirrename/dirrename
+unionfs/stress2/testcases/swap/swap
+"
+
+cp -r ../../stress2 $mp3
+export TESTPROGS=`echo $TESTPROGS | sed 's/\n/ /g'`
+
+set +e
+chmod 777 $mp3
+su $testuser -c \
+	"(cd $mp2; ./unionfs/stress2/testcases/run/run $TESTPROGS)"
+
+while mount | grep -Eq "on $mp3 .*unionfs"; do
+	umount $mp3 && break
+	sleep 5
+done
+umount $mp2
+n=`find $mp1/stressX | wc -l`
+[ $n -eq 1 ] && s=0 || { find $mp1/stressX -ls | head -12; s=1; }
+umount $mp1
+exit $s

tools/test/stress2/misc/unionfs23.sh

@@ -0,0 +1,77 @@
+#!/bin/sh
+
+#
+# Copyright (c) 2024 Peter Holm <[email protected]>
+# Copyright (c) 2026 Jason Harmening <[email protected]>
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+
+# unionfs(4) test
+# Variation of unionfs22.sh, but with '-o below'
+# Reproduces "lockmgr_xlock_hard: recursing on non recursive lockmgr"
+# panic (PR 298201)
+
+[ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
+. ../default.cfg
+
+mp1=/mnt$mdstart
+mp2=/mnt$((mdstart + 1))
+mp3=$mp2/unionfs
+
+mkdir -p $mp1 $mp2
+set -e
+for i in $mp1 $mp2; do
+	mount | grep -q "on $i " && umount -f $i
+done
+
+mount -o size=4g -t tmpfs dummy $mp1
+mount -o size=4g -t tmpfs dummy $mp2
+mkdir -p $mp3
+
+mount -t unionfs -o noatime -o below $mp1 $mp3
+set +e
+export 'INODES=100000'
+
+export CTRLDIR=$mp3/stressX.control
+export INCARNATIONS=10
+export LOAD=80
+export RUNDIR=$mp3/stressX
+export runRUNTIME=5m
+export rwLOAD=80
+export symlinkLOAD=80
+
+export TESTPROGS="
+unionfs/stress2/testcases/lockf2/lockf2
+unionfs/stress2/testcases/symlink/symlink
+unionfs/stress2/testcases/openat/openat
+unionfs/stress2/testcases/rw/rw
+unionfs/stress2/testcases/fts/fts
+unionfs/stress2/testcases/link/link
+unionfs/stress2/testcases/lockf/lockf
+unionfs/stress2/testcases/creat/creat
+unionfs/stress2/testcases/mkdir/mkdir
+unionfs/stress2/testcases/rename/rename
+unionfs/stress2/testcases/mkfifo/mkfifo
+unionfs/stress2/testcases/dirnprename/dirnprename
+unionfs/stress2/testcases/dirrename/dirrename
+unionfs/stress2/testcases/swap/swap
+"
+
+cp -r ../../stress2 $mp3
+export TESTPROGS=`echo $TESTPROGS | sed 's/\n/ /g'`
+
+set +e
+chmod 777 $mp3
+su $testuser -c \
+	"(cd $mp2; ./unionfs/stress2/testcases/run/run $TESTPROGS)"
+
+while mount | grep -Eq "on $mp3 .*unionfs"; do
+	umount $mp3 && break
+	sleep 5
+done
+n=`find $mp3/stressX | wc -l`
+[ $n -eq 1 ] && s=0 || { find $mp3/stressX -ls | head -12; s=1; }
+umount $mp2
+umount $mp1
+exit $s