From: "Timo Teräs" <timo.teras@iki•fi>
To: Herbert Xu <herbert@gondor•apana.org.au>
Cc: netdev@vger•kernel.org
Subject: Re: [PATCH 1/7] xfrm: remove policy lock when accessing policy->walk.dead
Date: Tue, 30 Mar 2010 15:04:01 +0300 [thread overview]
Message-ID: <4BB1E8B1.4030604@iki.fi> (raw)
In-Reply-To: <20100330115351.GA5731@gondor.apana.org.au>
Herbert Xu wrote:
> On Tue, Mar 30, 2010 at 07:55:07AM +0300, Timo Teräs wrote:
>> Herbert Xu wrote:
>>> On Mon, Mar 29, 2010 at 05:12:38PM +0300, Timo Teras wrote:
>>>> @@ -1132,7 +1119,7 @@ int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
>>>> __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
>>>> }
>>>> if (old_pol)
>>>> - __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
>>>> + old_pol = __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
>>>> write_unlock_bh(&xfrm_policy_lock);
>>>> if (old_pol) {
>>> So when can this actually fail?
>> Considering that the socket reference is received from the sk->sk_policy,
>> and the hash bucket we use is "XFRM_POLICY_MAX+dir", it's non-obvious if
>> it can fail or not.
>>
>> It would look like the timer can kill a policy and unlink it, but it
>> would still be found from sk_policy.
>
> Socket policies cannot expire.
Was not aware of that. The above is not needed then.
> In fact, they probably shouldn't even be on the bydst or any other
> hash table. I think the only reason they're there at all is because
> the hash table was added to __xfrm_policy_link which happens to be
> used by socket policies.
I think it's hashed so socket policies are included in the policy
db dumps and counts.
next prev parent reply other threads:[~2010-03-30 12:04 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-29 14:12 [PATCH 0/7] caching bundles, iteration 2 Timo Teras
2010-03-29 14:12 ` [PATCH 1/7] xfrm: remove policy lock when accessing policy->walk.dead Timo Teras
2010-03-29 14:43 ` Herbert Xu
2010-03-30 4:55 ` Timo Teräs
2010-03-30 11:53 ` Herbert Xu
2010-03-30 12:04 ` Timo Teräs [this message]
2010-03-30 12:14 ` Herbert Xu
2010-03-30 12:21 ` Timo Teräs
2010-03-30 12:23 ` Herbert Xu
2010-03-30 12:41 ` Timo Teräs
2010-03-30 12:48 ` Herbert Xu
2010-03-30 13:33 ` Timo Teräs
2010-03-30 14:30 ` Herbert Xu
2010-03-30 14:34 ` Herbert Xu
2010-03-30 14:37 ` Herbert Xu
2010-03-30 14:01 ` Timo Teräs
2010-03-30 14:29 ` Herbert Xu
2010-03-30 15:36 ` Timo Teräs
2010-03-31 0:43 ` Herbert Xu
2010-03-29 14:12 ` [PATCH 2/7] flow: structurize flow cache Timo Teras
2010-03-30 12:01 ` Herbert Xu
2010-03-30 12:02 ` Timo Teräs
2010-03-30 12:15 ` Herbert Xu
2010-03-29 14:12 ` [PATCH 3/7] flow: allocate hash table for online cpus only Timo Teras
2010-03-30 12:12 ` Herbert Xu
2010-03-31 12:32 ` Rusty Russell
2010-03-31 13:27 ` Timo Teräs
2010-03-29 14:12 ` [PATCH 4/7] flow: delayed deletion of flow cache entries Timo Teras
2010-03-30 12:22 ` Herbert Xu
2010-03-30 12:32 ` Timo Teräs
2010-03-30 12:36 ` Herbert Xu
2010-03-30 12:43 ` Timo Teräs
2010-03-29 14:12 ` [PATCH 5/7] flow: virtualize get and entry deletion methods Timo Teras
2010-03-29 14:12 ` [PATCH 6/7] xfrm: cache bundles instead of policies for outgoing flows Timo Teras
2010-03-29 14:12 ` [PATCH 7/7] xfrm: remove policy garbage collection Timo Teras
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