Re: [PATCH] qemu: hotplug: Fix the condition check for net->downscript

[Michal Privoznik <mprivozn@xxxxxxxxxx>]

On 5/29/20 5:52 PM, Yi Wang wrote:
> From: Liao Pingfang <liao.pingfang@xxxxxxxxxx>
>
> According to the context, here we are checking net->downscript's validity,
>
> Signed-off-by: Liao Pingfang <liao.pingfang@xxxxxxxxxx>
> ---
>   src/qemu/qemu_hotplug.c | 5 ++---
>   1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
> index d1a2be1..8c99dfc 100644
> --- a/src/qemu/qemu_hotplug.c
> +++ b/src/qemu/qemu_hotplug.c
> @@ -4672,9 +4672,8 @@ qemuDomainRemoveNetDevice(virQEMUDriverPtr driver,
>               virDomainNetReleaseActualDevice(conn, vm->def, net);
>           else
>               VIR_WARN("Unable to release network device '%s'", NULLSTR(net->ifname));
> -    } else if (net->type == VIR_DOMAIN_NET_TYPE_ETHERNET) {
> -        if (net->script)
> -           virNetDevRunEthernetScript(net->ifname, net->downscript);
> +    } else if (net->type == VIR_DOMAIN_NET_TYPE_ETHERNET && net->downscript) {
> +        virNetDevRunEthernetScript(net->ifname, net->downscript);
>       }
>       virDomainNetDefFree(net);
>       return 0;

I'm not quite sure why this change is needed and the commit message 
doesn't explain it well. My idea, when merging the original patch, was 
to have the following pattern:

  if (net->type == VIR_DOMAIN_NET_TYPE_NET) {
  } else if (net->type == VIR_DOMAAIN_NET_TYPE_ETHERNET) {
  } else if (net->type == ...) {
  }

because it's easily extensible (e.g. if another action needs to be taken 
for say ethernet type interface then all that's needed is to call a 
function from corresponding if(). If your patch is merged then it needs 
to be (effectively) reverted.

Can you elaborate on this please?

Michal