From: Cong Wang <amwang@redhat.com>
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: netdev@vger.kernel.org, "David S. Miller" <davem@davemloft.net>
Subject: Re: [Patch net-next] vxlan: do real refcnt for vn_sock
Date: Fri, 31 May 2013 12:12:11 +0800 [thread overview]
Message-ID: <1369973531.5304.4.camel@cr0> (raw)
In-Reply-To: <20130530205618.0d3a8d16@nehalam.linuxnetplumber.net>
On Thu, 2013-05-30 at 20:56 -0700, Stephen Hemminger wrote:
> On Fri, 31 May 2013 10:55:45 +0800
> Cong Wang <amwang@redhat.com> wrote:
>
> > On Wed, 2013-05-29 at 16:39 +0800, Cong Wang wrote:
> > > On Tue, 2013-05-28 at 21:41 -0700, Stephen Hemminger wrote:
> > > > Why not just fix the requirement to drop rtnl when calling igmp.
> > > > The code comes out cleaner and safer as well.
> > >
> > > Besides you forget to lock the socket before calling _ip_mc_join_group()
> > > (and also the order is very important too), your patch doesn't fix the
> > > problem I met. The full backtrace is below:
> > >
> >
> > Hi, Stephen,
> >
> > Do you think my patch is an easier solution? It at least fixes the
> > crash, while your patch doesn't. :)
> >
> >
>
> No. your patch doesn't fix the real problem.
> The real fix is more complex because of how socket locking interacts with RTNL.
Yeah, I am thinking if we could replace the RTNL lock with a spinlock in
IPv4 multicast, as IPv6 multicast uses its own spin lock too. I don't
see any reason why inet->mc_list has to be protected by RTNL.
>
>
> I have been busy with health stuff, so the going is slow.
No problem, take care!
prev parent reply other threads:[~2013-05-31 4:12 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-28 11:07 [Patch net-next] vxlan: do real refcnt for vn_sock Cong Wang
2013-05-28 15:22 ` Stephen Hemminger
2013-05-29 2:08 ` Cong Wang
2013-05-29 4:22 ` Stephen Hemminger
2013-05-29 4:34 ` Cong Wang
2013-05-29 4:01 ` Cong Wang
2013-05-29 4:41 ` Stephen Hemminger
2013-05-29 5:14 ` Cong Wang
2013-05-29 8:39 ` Cong Wang
2013-05-31 2:55 ` Cong Wang
2013-05-31 3:56 ` Stephen Hemminger
2013-05-31 4:12 ` Cong Wang [this message]
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