Index: head/tools/regression/geom_subr.sh
===================================================================
--- head/tools/regression/geom_subr.sh	(revision 293028)
+++ head/tools/regression/geom_subr.sh	(revision 293029)
@@ -1,19 +1,48 @@
 #!/bin/sh
 # $FreeBSD$
 
 if [ $(id -u) -ne 0 ]; then
 	echo 'Tests must be run as root'
 	echo 'Bail out!'
 	exit 1
 fi
 kldstat -q -m g_${class} || geom ${class} load || exit 1
 
 devwait()
 {
 	while :; do
 		if [ -c /dev/${class}/${name} ]; then
 			return
 		fi
 		sleep 0.2
 	done
 }
+
+# Need to keep track of the test md devices to avoid the scenario where a test
+# failing will cause the other tests to bomb out, or a test failing will leave
+# a large number of md(4) devices lingering around
+: ${TMPDIR=/tmp}
+export TMPDIR
+TEST_MDS_FILE=${TMPDIR}/test_mds
+
+attach_md()
+{
+	local test_md
+
+	test_md=$(mdconfig -a "$@") || exit
+	echo $test_md >> $TEST_MDS_FILE || exit
+	echo $test_md
+}
+
+geom_test_cleanup()
+{
+	local test_md
+
+	if [ -f $TEST_MDS_FILE ]; then
+		while read test_md; do
+			# The "#" tells the TAP parser this is a comment
+			echo "# Removing test memory disk: $test_md"
+			mdconfig -d -u $test_md
+		done < $TEST_MDS_FILE
+	fi
+}