return $params{'res_cb'}->($err, undef);
} elsif ($err->failed && $err->volinuse and defined $err->{'slot'}) {
$last_slot = $err->{'slot'};
return $params{'res_cb'}->($err, undef);
} elsif ($err->failed && $err->volinuse and defined $err->{'slot'}) {
$last_slot = $err->{'slot'};