From: Jakub Sitnicki <jkbs@redhat•com>
To: Kevin Xu <kaiwen.xu@hulu•com>
Cc: "davem\@davemloft.net" <davem@davemloft•net>,
"netdev\@vger.kernel.org" <netdev@vger•kernel.org>
Subject: Re: [PATCH] [PATCH net] net: Do not hold the reference for the same sk_rx_dst.
Date: Thu, 16 Mar 2017 11:45:03 +0100 [thread overview]
Message-ID: <87fuidv6ts.fsf@redhat.com> (raw)
In-Reply-To: <242C9F89-8639-4C31-B3E5-B56C4F785E41@hulu.com>
On Thu, Mar 16, 2017 at 10:12 AM GMT, Kevin Xu wrote:
> Do you mean the message looping endlessly?
No, the message is emitted just once. Around 100 seconds after
destroying a few namespaces. Occurs not so often, maybe once per ten
runs.
-Jakub
> If so, then I suppose it's a different bug.
>
> Kevin
>
>> On Mar 16, 2017, at 3:01 AM, Jakub Sitnicki <jkbs@redhat•com> wrote:
>>
>>> On Thu, Mar 16, 2017 at 08:08 AM GMT, Kevin Xu wrote:
>>> In some rare cases, inet_sk_rx_dst_set() may be called multiple times
>>> on the same dst, causing reference count leakage. Eventually, it
>>> prevents net_device to be destroyed. The bug then manifested as
>>>
>>> unregister_netdevice: waiting for lo to become free. Usage count = 1
>>>
>>> in the kernel log, preventing new network namespace creation.
>>>
>>> The patch works around the issue by checking whether the socket already
>>> has the same dst set.
>>>
>>> Signed-off-by: Kevin Xu <kaiwen.xu@hulu•com>
>>> ---
>>
>> FWIW, with this patch applied I'm still sometimes seeing:
>>
>> [ 125.928095] unregister_netdevice: waiting for lo to become free. Usage count = 1
>>
>> -Jakub
next prev parent reply other threads:[~2017-03-16 10:45 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-16 8:08 [PATCH] [PATCH net] net: Do not hold the reference for the same sk_rx_dst Kevin Xu
2017-03-16 10:01 ` Jakub Sitnicki
2017-03-16 10:12 ` Kevin Xu
2017-03-16 10:45 ` Jakub Sitnicki [this message]
2017-03-16 18:18 ` Kaiwen Xu
2017-03-16 18:42 ` Cong Wang
2017-03-16 18:16 ` David Miller
2017-03-19 1:48 ` [PATCH net v2] " Kevin Xu
2017-03-19 3:49 ` Cong Wang
2017-03-19 4:03 ` Kaiwen Xu
2017-03-20 4:09 ` Cong Wang
2017-03-20 21:23 ` Kaiwen Xu
2017-03-16 21:33 ` [PATCH] [PATCH net] " Eric Dumazet
2017-03-16 23:13 ` Cong Wang
2017-03-16 23:29 ` Eric Dumazet
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