netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
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 07:55:07 +0300	[thread overview]
Message-ID: <4BB1842B.9010704@iki.fi> (raw)
In-Reply-To: <20100329144339.GA26214@gondor.apana.org.au>

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.

It probably doesn't really make sense to insert per-socket policy that
expires. But in case someone does something like that, I'd think we
need the above just to be sure.

Considering this, xfrm_sk_policy_lookup() should probably check the
dead flag, and cleanup sk_policy if it was killed by a timer.

  reply	other threads:[~2010-03-30  4:55 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 [this message]
2010-03-30 11:53       ` Herbert Xu
2010-03-30 12:04         ` Timo Teräs
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4BB1842B.9010704@iki.fi \
    --to=timo.teras@iki.fi \
    --cc=herbert@gondor.apana.org.au \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).