fix #4457: use bridge mtu if no mtu is defined

Signed-off-by: Alexandre Derumier <aderumier@odiso.com>

diff --git a/src/PVE/LXC.pm b/src/PVE/LXC.pm
index e582a942cc7c657ec8d0644fadc2d8c5dca88437..92c1b60544460eb1dd98c8c72bf957e7ef586b6b 100644 (file)
--- a/src/PVE/LXC.pm
+++ b/src/PVE/LXC.pm
@@ -733,14 +733,14 @@ sub update_lxc_config {
        $raw .= "lxc.net.$ind.hwaddr = $d->{hwaddr}\n" if defined($d->{hwaddr});
        $raw .= "lxc.net.$ind.name = $d->{name}\n" if defined($d->{name});
 
+       my $bridge_mtu = PVE::Network::read_bridge_mtu($d->{bridge});
+       my $mtu = $d->{mtu} || $bridge_mtu;
+
        # Keep container from starting with invalid mtu configuration
-       if (my $mtu = $d->{mtu}) {
-           my $bridge_mtu = PVE::Network::read_bridge_mtu($d->{bridge});
-           die "$k: MTU size '$mtu' is bigger than bridge MTU '$bridge_mtu'\n"
-               if ($mtu > $bridge_mtu);
+       die "$k: MTU size '$mtu' is bigger than bridge MTU '$bridge_mtu'\n"
+           if ($mtu > $bridge_mtu);
 
-           $raw .= "lxc.net.$ind.mtu = $mtu\n";
-       }
+       $raw .= "lxc.net.$ind.mtu = $mtu\n";
 
        # Starting with lxc 4.0, we do not patch lxc to execute our up-scripts.
        if ($lxc_major >= 4) {