command: get_cgroup_path: handle undef subsystem

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

diff --git a/src/PVE/LXC/Command.pm b/src/PVE/LXC/Command.pm
index 825c354aad1c4f2e22bd4dd2f8f3dee32445309e..0a52d47f4d54f534e17418fb4baecb2ce0e8b556 100644 (file)
--- a/src/PVE/LXC/Command.pm
+++ b/src/PVE/LXC/Command.pm
@@ -165,7 +165,7 @@ sub get_cgroup_path($;$$) {
     my ($res, $data) = simple_command(
        $vmid,
        $limiting ? LXC_CMD_GET_LIMITING_CGROUP : LXC_CMD_GET_CGROUP,
-       pack('Z*', $subsystem),
+       defined($subsystem) && pack('Z*', $subsystem),
     );
     return undef if !defined $res;