tests: aux check for leaked symlinks

Add check for 'leaked' symlinks after test and trap
the case when some 'danglink' links are present.
This might be some problem with udev synchronization
or some other strange race.

All such symlinks will be also removed so they will not
influence following tests.

test/lib/aux.sh

@@ -632,13 +632,31 @@ teardown() {
 	}
 
 	# Remove any dangling symlink in /dev/disk (our tests can confuse udev)
-	test -d /dev/disk && {
+	find /dev/disk -type l -exec test ! -e {} \; -print0 2>/dev/null | xargs -0 rm -f || true
-		find /dev/disk -type l ! -exec /usr/bin/test -e {} \; -print0 | xargs -0 rm -f || true
-	}
 
 	# Remove any metadata archives and backups from this test on system
 	rm -f /etc/lvm/archive/"${PREFIX}"* /etc/lvm/backup/"${PREFIX}"*
 
+	# Check if this test is leaking some 'symlinks' with our name (udev)
+	LEAKED_LINKS=( $(find /dev -path "/dev/mapper/${PREFIX}*" -type l -exec test ! -e {} \; -print -o \
+		-path "/dev/${PREFIX}*/" -type l -exec test ! -e {} \; -print  2>/dev/null || true) )
+
+	if test "${LVM_TEST_PARALLEL:-0}" = 0 ; then
+		# for non parallel testing erase any dangling links prefixed with LVMTEST
+		find /dev -path "/dev/mapper/${COMMON_PREFIX}*" -type l -exec test ! -e {} \; -print0 -o \
+			-path "/dev/${COMMON_PREFIX}*" -type l -exec test ! -e {} \; -print0 2>/dev/null | xargs -0 rm -f || true
+		LEAKED_PREFIX=${COMMON_PREFIX}
+	else
+		rm -f "${LEAKED_LINKS[@]}" || true
+		LEAKED_PREFIX=${PREFIX}
+	fi
+
+	# Remove empty dirs with test prefix
+	find /dev -type d -name "${LEAKED_PREFIX}*" -empty -delete 2>/dev/null || true
+
+	# Fail test with leaked links as most likely somewhere is missing synchronization...
+	test "${#LEAKED_LINKS[@]}" -eq 0 || die "Test leaked these symlinks ${LEAKED_LINKS[@]}"
+
 	echo "ok"
 }