From: ebiederm@xmission.com (Eric W. Biederman)
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Paul Moore <paul.moore@hp.com>,
netdev@vger.kernel.org, David Miller <davem@davemloft.net>
Subject: Re: [RFC PATCH v1] tun: Cleanup error handling in tun_set_iff()
Date: Thu, 06 Aug 2009 03:21:41 -0700 [thread overview]
Message-ID: <m1hbwlkzt6.fsf@fess.ebiederm.org> (raw)
In-Reply-To: <20090806101044.GA26589@gondor.apana.org.au> (Herbert Xu's message of "Thu\, 6 Aug 2009 20\:10\:44 +1000")
Herbert Xu <herbert@gondor.apana.org.au> writes:
> On Wed, Aug 05, 2009 at 05:38:42PM -0400, Paul Moore wrote:
>>
>> My concern is that I believe that if the kernel fails at an operation it
>> should do all it can to unwind any actions it took in the course of attempting
>> to perform the requested operation. Leaving a TUN device around in the case
>> of a tun_attach() failure seems like the kernel is being lazy, sure a user can
>> cleanup the device but why should they have to?
>
> That particular tun_attach should never fail. Perhaps you can
> just add a WARN_ON.
Two threads one file descriptor. Both simultaneously attempt to
attach to a tun device. One will fail, the other succeed.
At least that is how I read the locking.
Eric
next prev parent reply other threads:[~2009-08-06 10:21 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-03 16:12 [RFC PATCH v1] tun: Cleanup error handling in tun_set_iff() Paul Moore
2009-08-04 4:16 ` David Miller
2009-08-05 5:32 ` Eric W. Biederman
2009-08-05 21:38 ` Paul Moore
2009-08-05 23:14 ` Eric W. Biederman
2009-08-06 18:20 ` Paul Moore
2009-08-07 0:00 ` Herbert Xu
2009-08-07 12:23 ` Paul Moore
2009-08-06 10:10 ` Herbert Xu
2009-08-06 10:21 ` Eric W. Biederman [this message]
2009-08-06 13:37 ` Herbert Xu
2009-08-06 14:27 ` Eric W. Biederman
2009-08-06 14:39 ` Herbert Xu
2009-08-06 15:02 ` Eric W. Biederman
2009-08-06 18:09 ` Paul Moore
2009-08-06 18:41 ` David Miller
2009-08-07 0:22 ` Herbert Xu
2009-08-07 3:40 ` David Miller
2009-08-07 4:22 ` Eric W. Biederman
2009-08-10 4:52 ` David Miller
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