Change Details

`EthernetIf.remove()` snapshots `Section.sub_interfaces()` once and then removes every entry of that list. For QinQ setups the list contains both the vif-s (eth0.10) and its vif-c children (eth0.10.20). As `Section.sub_interfaces()` matches every configured interface whose name starts with "<ifname>." Removing `eth0.10` cascades in the kernel and also deletes `eth0.10.20`. Once the loop reaches `eth0.10.20`, `Interface.__init__()` no longer finds it and - as "create" defaults to True - re-creates it via a bare `ip link add dev eth0.10.20` without any type. This fails and leaves a stranded interface behind which in turn breaks all subsequent smoketests.

`EthernetIf.remove()` snapshotted `Section.sub_interfaces()` once and then removed every entry of that list. For Q-in-Q setups the list contains both the vif-s (eth0.10) and its vif-c children (eth0.10.20), as `Section.sub_interfaces()` matches every configured interface whose name starts with "<ifname>.". Removing eth0.10 cascades in the Kernel and also deletes eth0.10.20. Once the loop reached eth0.10.20, `Interface.__init__()` no longer found it and - as "create" defaults to True, re-created it via a bare `ip link add dev eth0.10.20` without any type. This failed and left a stranded interface behind which in turn broke all subsequent smoketests. The same cascade silently killed DHCP clients running on sub-interfaces of any other interface type, as only the interface itself got its addresses flushed: * deletion of a bond or bridge interface carrying vif/vif-s/vif-c * deletion of an entire vif-s, as `get_removed_vlans()` only populates "vif_c_remove" for a vif-s which still exists in the new configuration

`EthernetIf.remove()` snapshotsted `Section.sub_interfaces()` once and then removesd every entry of that list. For QinQ-in-Q setups the list contains both the vif-s (eth0.10) and its vif-c children (eth0.10.20).20), Aas `Section.sub_interfaces()` matches every configured interface whose name starts with "<ifname>.". Removing `eth0.10` cascades in the kKernel and also deletes `eth0.10.20`. Once the loop reaches `d eth0.10.20`, `Interface.__init__()` no longer findsound it and - as "create" defaults to True -, re-createsd it via a bare `ip link add dev eth0.10.20` without any type. This failed and left a stranded interface behind which in turn broke all subsequent smoketests. The same cascade silently killed DHCP clients running on sub-interfaces of any other interface type, This fails and leaves a stranded interface behind which in turn breaks all subsequent smoketests.as only the interface itself got its addresses flushed: * deletion of a bond or bridge interface carrying vif/vif-s/vif-c * deletion of an entire vif-s, as `get_removed_vlans()` only populates "vif_c_remove" for a vif-s which still exists in the new configuration