[libvirt] [PATCH]util:ovs:Delete port if it is exist when add port

[Michal Privoznik]

On 03.07.2014 13:57, Lichunhe wrote:
> If the ovs service stop abnormal, or host cold reboot, vm is destroyed after ovs service stop. The ovs
> port which connect to interface of vm will not be clear. When the ovs service restart, recover configuration
> from db, but the interface is no exist, port recovery failed, and then vm restart on the same host,
> libvirt add port again, but the port configuration is same as before, ovs will not connect the interface,
> only store the configuration in db. Below will trigger this problem,
>
> virsh start vm
> service openvswitch-switch stop
> virsh destroy vm
> service openvswitch-switch start
> virsh start vm
>
>
> Signed-off-by: Chunhe Li <lichunhe at huawei.com>
> ---
>
> src/util/virnetdevopenvswitch.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/src/util/virnetdevopenvswitch.c b/src/util/virnetdevopenvswitch.c
> index 9bcbfb1..dd601c0 100644
> --- a/src/util/virnetdevopenvswitch.c
> +++ b/src/util/virnetdevopenvswitch.c
> @@ -84,7 +84,8 @@ int virNetDevOpenvswitchAddPort(const char *brname, const char *ifname,
>
>       cmd = virCommandNew(OVSVSCTL);
>
> -    virCommandAddArgList(cmd, "--timeout=5", "--", "--may-exist", "add-port",
> +    virCommandAddArgList(cmd, "--timeout=5", "--", "--if-exists", "del-port",
> +                        ifname, "--", "--may-exist", "add-port",
>                           brname, ifname, NULL);

So what's the meaning of '--may-exist' then? Does it do anything useful 
after all?

Michal