From mboxrd@z Thu Jan  1 00:00:00 1970
From: "David S. Miller" <davem@davemloft.net>
Subject: Re: race in net/ipv4/ipip.c ?
Date: Wed, 12 Jan 2005 11:02:10 -0800
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To: Thomas Graf <tgraf@suug.ch>
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On Wed, 12 Jan 2005 14:21:26 +0100
Thomas Graf <tgraf@suug.ch> wrote:

> * YOSHIFUJI Hideaki / ?$B5HF#1QL@ <20050112.220816.56650893.yoshfuji@linux-ipv6.org> 2005-01-12 22:08
> > How about adding multiple tunnels (with same ipip_bucket(t))
> > concurrently? :-)
> > 
> 
> * Lennert Buytenhek <20050112130940.GA12547@xi.wantstofly.org> 2005-01-12 14:09
> > What if you add two tunnels at the same time?  (Or is that perhaps
> > synchronised on a higher level?)
> 
> Not possible, protected via rtnl semaphore acquired in default
> handler of dev_ioctl.

Yeah.  Alexey does this trick everywhere, when we have the RTNL semaphore
held we only need to lock for the actual linkage operation that adds the
new object to the tree.