[Qemu-devel] Re: [PATCH] tun: orphan an skb on tx

[Eric Dumazet]

Le mardi 13 avril 2010 à 17:36 +0200, Jan Kiszka a écrit :
> Michael S. Tsirkin wrote:
> > The following situation was observed in the field:
> > tap1 sends packets, tap2 does not consume them, as a result
> > tap1 can not be closed.
> 
> And before that, tap1 may not be able to send further packets to anyone
> else on the bridge as its TX resources were blocked by tap2 - that's
> what we saw in the field.
> 

After the patch, tap1 is able to flood tap2, and tap3/tap4 not able to
send one single frame. Is it OK ?

Back to the problem : tap1 cannot be closed.

Why ? because of refcounts ?

When a socket with inflight tx packets is closed, we dont block the
close, we only delay the socket freeing once all packets were delivered
and freed.