[libvirt] [PATCH] nwfilter: directly use poll to wait for packets instead of pcap_next

[John Ferlan]

On 05/21/2018 08:15 AM, Daniel P. Berrangé wrote:
> When a QEMU VM shuts down its TAP device gets deleted while nwfilter
> IP address learning thread is still capturing packets. It is seen that
> with TPACKET_V3 support in libcap, the pcap_next() call will not always
> exit its poll() when the NIC is removed. This prevents the learning
> thread from exiting which blocks the rest of libvirtd waiting on mutex
> acquisition. By switching to do poll() in libvirt code, we can ensure
> that we always exit the poll() at a time that is right for libvirt.
> 
> Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
> ---
>  src/nwfilter/nwfilter_learnipaddr.c | 37 +++++++++++++++++++++++++++--
>  1 file changed, 35 insertions(+), 2 deletions(-)
> 

FWIW: This patch is related to:

https://www.redhat.com/archives/libvir-list/2018-May/msg01440.html

Reviewed-by: John Ferlan <jferlan at redhat.com>

I think this needs to be pushed before the release! Since Daniel is
away, I can take care of that.  I will wait for Monday though to ensure
there's no objection...

There's also a companion patch:

https://www.redhat.com/archives/libvir-list/2018-May/msg01429.html

but I have some issues with that and will post an alternative that would
also need to be pushed before the release.

John