From: Vlad Buslov <vladbu@mellanox•com>
To: Cong Wang <xiyou.wangcong@gmail•com>
Cc: Linux Kernel Network Developers <netdev@vger•kernel.org>,
Jamal Hadi Salim <jhs@mojatatu•com>,
Jiri Pirko <jiri@resnulli•us>, David Miller <davem@davemloft•net>
Subject: Re: [PATCH net-next] net: sched: set dedicated tcf_walker flag when tp is empty
Date: Tue, 26 Feb 2019 15:08:45 +0000 [thread overview]
Message-ID: <vbf4l8qmvt4.fsf@mellanox.com> (raw)
In-Reply-To: <CAM_iQpWmRQP8-xBiULnCDHkDTHW7WaKuBmcsYJ7j-yRxfgwOaA@mail.gmail.com>
On Mon 25 Feb 2019 at 22:52, Cong Wang <xiyou.wangcong@gmail•com> wrote:
> On Mon, Feb 25, 2019 at 7:38 AM Vlad Buslov <vladbu@mellanox•com> wrote:
>>
>> Using tcf_walker->stop flag to determine when tcf_walker->fn() was called
>> at least once is unreliable. Some classifiers set 'stop' flag on error
>> before calling walker callback, other classifiers used to call it with NULL
>> filter pointer when empty. In order to prevent further regressions, extend
>> tcf_walker structure with dedicated 'nonempty' flag. Set this flag in
>> tcf_walker->fn() implementation that is used to check if classifier has
>> filters configured.
>
>
> So, after this patch commits like 31a998487641 ("net: sched: fw: don't
> set arg->stop in fw_walk() when empty") can be reverted??
Yes, it is safe now to revert following commits:
3027ff41f67c ("net: sched: route: don't set arg->stop in route4_walk() when empty")
31a998487641 ("net: sched: fw: don't set arg->stop in fw_walk() when empty")
>
>
>>
>> Fixes: 8b64678e0af8 ("net: sched: refactor tp insert/delete for concurrent execution")
>> Signed-off-by: Vlad Buslov <vladbu@mellanox•com>
>> Suggested-by: Cong Wang <xiyou.wangcong@gmail•com>
>> ---
>> include/net/pkt_cls.h | 1 +
>> net/sched/cls_api.c | 13 +++++++++----
>> 2 files changed, 10 insertions(+), 4 deletions(-)
>>
>> diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
>> index 232f801f2a21..422dd8800478 100644
>> --- a/include/net/pkt_cls.h
>> +++ b/include/net/pkt_cls.h
>> @@ -17,6 +17,7 @@ struct tcf_walker {
>> int stop;
>> int skip;
>> int count;
>> + bool nonempty;
>> unsigned long cookie;
>> int (*fn)(struct tcf_proto *, void *node, struct tcf_walker *);
>> };
>> diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
>> index e2c888961379..3543be31d400 100644
>> --- a/net/sched/cls_api.c
>> +++ b/net/sched/cls_api.c
>> @@ -238,18 +238,23 @@ static void tcf_proto_put(struct tcf_proto *tp, bool rtnl_held,
>> tcf_proto_destroy(tp, rtnl_held, extack);
>> }
>>
>> -static int walker_noop(struct tcf_proto *tp, void *d, struct tcf_walker *arg)
>> +static int walker_check_empty(struct tcf_proto *tp, void *d,
>> + struct tcf_walker *arg)
>> {
>> - return -1;
>> + if (tp) {
>> + arg->nonempty = true;
>> + return -1;
>> + }
>> + return 0;
>
> How does this even work? If we can simply check tp!=NULL as
> non-empty, why do we even need a walker??
>
> For me, it must be pushed down to each implementation to
> determine how it is empty.
Sorry, this is a typo. Intention is to check the filter pointer (void
*d). Sending the fix.
Thanks for spotting this!
next prev parent reply other threads:[~2019-02-26 15:09 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-25 15:38 [PATCH net-next] net: sched: set dedicated tcf_walker flag when tp is empty Vlad Buslov
2019-02-25 18:18 ` David Miller
2019-02-25 22:52 ` Cong Wang
2019-02-26 15:08 ` Vlad Buslov [this message]
2019-02-26 22:38 ` Cong Wang
2019-02-27 14:28 ` Vlad Buslov
2019-02-27 23:09 ` Cong Wang
2019-02-28 15:49 ` Vlad Buslov
2019-03-02 1:17 ` Cong Wang
2019-03-04 13:57 ` Vlad Buslov
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