From: Paul Blakey <paulb@mellanox.com>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Oz Shlomo <ozsh@mellanox.com>, Roi Dayan <roid@mellanox.com>,
netdev@vger.kernel.org, Saeed Mahameed <saeedm@mellanox.com>,
netfilter-devel@vger.kernel.org
Subject: Re: [PATCH net] netfilter: flowtable: Fix expired flow not being deleted from software
Date: Mon, 11 May 2020 10:24:44 +0300 [thread overview]
Message-ID: <a420c22a-9d52-c314-cf9b-ee19831e15a7@mellanox.com> (raw)
In-Reply-To: <20200510222640.GA11645@salvia>
On 5/11/2020 1:26 AM, Pablo Neira Ayuso wrote:
> On Wed, May 06, 2020 at 02:27:29PM +0300, Paul Blakey wrote:
>> Once a flow is considered expired, it is marked as DYING, and
>> scheduled a delete from hardware. The flow will be deleted from
>> software, in the next gc_step after hardware deletes the flow
>> (and flow is marked DEAD). Till that happens, the flow's timeout
>> might be updated from a previous scheduled stats, or software packets
>> (refresh). This will cause the gc_step to no longer consider the flow
>> expired, and it will not be deleted from software.
>>
>> Fix that by looking at the DYING flag as in deciding
>> a flow should be deleted from software.
> Would this work for you?
>
> The idea is to skip the refresh if this has already expired.
>
> Thanks.
The idea is ok, but timeout check + update isn't atomic (need atomic_inc_unlesss
or something like that), and there is also
the hardware stats which if comes too late (after gc finds it expired) might
bring a flow back to life.
next prev parent reply other threads:[~2020-05-11 7:24 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-06 11:27 [PATCH net] netfilter: flowtable: Fix expired flow not being deleted from software Paul Blakey
2020-05-10 22:26 ` Pablo Neira Ayuso
2020-05-11 7:24 ` Paul Blakey [this message]
2020-05-11 8:42 ` Pablo Neira Ayuso
2020-05-11 9:50 ` Paul Blakey
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=a420c22a-9d52-c314-cf9b-ee19831e15a7@mellanox.com \
--to=paulb@mellanox.com \
--cc=netdev@vger.kernel.org \
--cc=netfilter-devel@vger.kernel.org \
--cc=ozsh@mellanox.com \
--cc=pablo@netfilter.org \
--cc=roid@mellanox.com \
--cc=saeedm@mellanox.com \
/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).