From: Ben Greear <greearb@candelatech.com>
To: Stephen Hemminger <shemminger@vyatta.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
Patrick McHardy <kaber@trash.net>,
Linux Netdev List <netdev@vger.kernel.org>,
"David S. Miller" <davem@davemloft.net>
Subject: Re: IPv4/IPv6 sysctl unregistration deadlock
Date: Mon, 02 Mar 2009 14:11:07 -0800 [thread overview]
Message-ID: <49AC597B.4090404@candelatech.com> (raw)
In-Reply-To: <20090227103812.14af52b3@nehalam>
Stephen Hemminger wrote:
> On Fri, 27 Feb 2009 10:26:43 -0800
> Ben Greear <greearb@candelatech.com> wrote:
>
>> Stephen Hemminger wrote:
>>
>>> Subject: [PATCH] Avoid race between network down and sysfs
>>>
>>>
>>> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
>>>
>>> --- a/net/core/net-sysfs.c 2009-02-26 08:36:18.000000000 -0800
>>> +++ b/net/core/net-sysfs.c 2009-02-26 08:37:51.000000000 -0800
>>> @@ -77,7 +77,9 @@ static ssize_t netdev_store(struct devic
>>> if (endp == buf)
>>> goto err;
>>>
>>> - rtnl_lock();
>>> + if (!rtnl_trylock())
>>> + return -ERESTARTSYS;
>>> +
>>> if (dev_isalive(net)) {
>>> if ((ret = (*set)(net, new)) == 0)
>>> ret = len;
>> I can test this to see if it fixes my problem. Are the above lines the
>> entirety of the patch?
>
> yes
With both of Stephen's patches included in the latest -rc6 source,
I re-ran the test and it seems to be working (I added printks so
that I would know the new code was being exercised)
I had 2000 or so mac-vlans configured, with 10 of them being
re-configured concurrently, while also deleting groups of 20-100
mac-vlans in my test. This was locking up reliably before,
and now it seems to be working fine.
Here's the kernel log showing the ERESTARTSYS in action. I don't
have an easy way to check to see if the VFS (or whatever) retried
the call properly, but will let you all know if I see any indication
that isn't working.
I only saw the ipv6 fixup in my logs, but maybe my test case just
doesn't hit the other...
Mar 2 13:37:41 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:37:41 simech-1 kernel: ADDRCONF(NETDEV_UP): eth1: link is not ready
Mar 2 13:37:42 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:38:13 simech-1 kernel:last message repeated 42 times
Mar 2 13:39:20 simech-1 kernel:last message repeated 71 times
Mar 2 13:40:13 simech-1 kernel:last message repeated 68 times
Mar 2 13:40:13 simech-1 dhclient: DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 8
Mar 2 13:40:13 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:40:21 simech-1 kernel:last message repeated 11 times
Mar 2 13:40:21 simech-1 dhclient: DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 13
Mar 2 13:40:21 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:40:28 simech-1 kernel:last message repeated 16 times
Mar 2 13:40:28 simech-1 kernel: __ratelimit: 3352 callbacks suppressed
Mar 2 13:40:28 simech-1 kernel: Neighbour table overflow.
Mar 2 13:40:28 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:40:34 simech-1 kernel:last message repeated 8 times
Mar 2 13:40:34 simech-1 dhclient: DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 20
Mar 2 13:40:34 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:40:54 simech-1 kernel:last message repeated 42 times
Mar 2 13:40:54 simech-1 dhclient: DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 7
Mar 2 13:40:54 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:41:01 simech-1 kernel:last message repeated 13 times
Mar 2 13:41:01 simech-1 dhclient: DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 13
Mar 2 13:41:01 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:41:14 simech-1 kernel:last message repeated 26 times
Mar 2 13:41:14 simech-1 dhclient: No DHCPOFFERS received.
Mar 2 13:41:14 simech-1 dhclient: No working leases in persistent database - sleeping.
Mar 2 13:41:15 simech-1 dhclient: receive_packet failed on eth1: Network is down
Mar 2 13:41:16 simech-1 kernel: ADDRCONF(NETDEV_UP): eth1: link is not ready
Mar 2 13:41:17 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:41:24 simech-1 kernel:last message repeated 16 times
Mar 2 13:41:24 simech-1 kernel: Neighbour table overflow.
Mar 2 13:41:25 simech-1 kernel:last message repeated 8 times
Mar 2 13:41:25 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:41:30 simech-1 kernel:last message repeated 11 times
Mar 2 13:41:30 simech-1 kernel: __ratelimit: 7059 callbacks suppressed
Mar 2 13:41:30 simech-1 kernel: Neighbour table overflow.
Mar 2 13:41:30 simech-1 kernel:last message repeated 9 times
Mar 2 13:41:30 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:41:35 simech-1 kernel:last message repeated 10 times
Mar 2 13:41:35 simech-1 kernel: __ratelimit: 7973 callbacks suppressed
Mar 2 13:41:35 simech-1 kernel: Neighbour table overflow.
Mar 2 13:41:36 simech-1 kernel:last message repeated 9 times
Mar 2 13:41:36 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:41:40 simech-1 kernel:last message repeated 7 times
Mar 2 13:41:40 simech-1 kernel: __ratelimit: 10890 callbacks suppressed
Mar 2 13:41:40 simech-1 kernel: Neighbour table overflow.
Mar 2 13:41:40 simech-1 kernel:last message repeated 9 times
Mar 2 13:41:40 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:41:46 simech-1 kernel:last message repeated 13 times
Mar 2 13:41:46 simech-1 kernel: __ratelimit: 6571 callbacks suppressed
Mar 2 13:41:46 simech-1 kernel: Neighbour table overflow.
Mar 2 13:41:46 simech-1 kernel:last message repeated 9 times
Mar 2 13:41:46 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:41:51 simech-1 kernel:last message repeated 7 times
Mar 2 13:41:51 simech-1 kernel: __ratelimit: 15491 callbacks suppressed
Mar 2 13:41:51 simech-1 kernel: Neighbour table overflow.
Mar 2 13:41:51 simech-1 kernel:last message repeated 9 times
Mar 2 13:41:51 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:41:56 simech-1 kernel:last message repeated 9 times
Mar 2 13:41:56 simech-1 kernel: __ratelimit: 9658 callbacks suppressed
Mar 2 13:41:56 simech-1 kernel: Neighbour table overflow.
Mar 2 13:41:56 simech-1 kernel:last message repeated 9 times
Mar 2 13:41:56 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:42:01 simech-1 kernel:last message repeated 10 times
Mar 2 13:42:01 simech-1 kernel: __ratelimit: 12678 callbacks suppressed
Mar 2 13:42:01 simech-1 kernel: Neighbour table overflow.
Mar 2 13:42:01 simech-1 kernel:last message repeated 9 times
Mar 2 13:42:01 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:42:06 simech-1 kernel:last message repeated 7 times
Mar 2 13:42:06 simech-1 kernel: __ratelimit: 13401 callbacks suppressed
Mar 2 13:42:06 simech-1 kernel: Neighbour table overflow.
Mar 2 13:42:06 simech-1 kernel:last message repeated 9 times
Mar 2 13:42:06 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:42:11 simech-1 kernel:last message repeated 10 times
Mar 2 13:42:11 simech-1 kernel: __ratelimit: 11875 callbacks suppressed
Mar 2 13:42:11 simech-1 kernel: Neighbour table overflow.
Mar 2 13:42:11 simech-1 kernel:last message repeated 9 times
Mar 2 13:42:11 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Mar 2 13:42:16 simech-1 kernel:last message repeated 9 times
Mar 2 13:42:16 simech-1 kernel: __ratelimit: 9362 callbacks suppressed
Mar 2 13:42:16 simech-1 kernel: Neighbour table overflow.
Mar 2 13:42:17 simech-1 kernel:last message repeated 9 times
Mar 2 13:42:17 simech-1 kernel: Returning ERESTARTSYS in ipv6-addrconf-fixup-forwarding to avoid deadlock.
Thanks,
Ben
--
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc http://www.candelatech.com
next prev parent reply other threads:[~2009-03-02 22:11 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-25 5:23 IPv4/IPv6 sysctl unregistration deadlock Patrick McHardy
2009-02-25 6:19 ` Herbert Xu
2009-02-25 6:23 ` Patrick McHardy
2009-02-25 7:18 ` Patrick McHardy
2009-02-25 8:43 ` Herbert Xu
2009-02-26 6:06 ` Eric W. Biederman
2009-02-26 6:10 ` Eric W. Biederman
2009-02-26 6:22 ` Herbert Xu
2009-02-26 7:18 ` Eric W. Biederman
2009-02-26 16:49 ` Stephen Hemminger
2009-02-26 19:01 ` Eric W. Biederman
2009-02-26 20:24 ` Stephen Hemminger
2009-02-27 0:59 ` Herbert Xu
2009-02-27 1:25 ` Stephen Hemminger
2009-02-27 18:26 ` Ben Greear
2009-02-27 18:38 ` Stephen Hemminger
2009-03-02 11:07 ` Patrick McHardy
2009-03-02 11:21 ` Patrick McHardy
2009-03-02 22:11 ` Ben Greear [this message]
2009-03-02 22:20 ` Patrick McHardy
2009-03-02 22:47 ` David Miller
2009-03-02 23:03 ` Patrick McHardy
2009-03-03 8:48 ` David Miller
2009-03-08 3:36 ` Eric W. Biederman
2009-02-26 16:55 ` Stephen Hemminger
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=49AC597B.4090404@candelatech.com \
--to=greearb@candelatech.com \
--cc=davem@davemloft.net \
--cc=ebiederm@xmission.com \
--cc=herbert@gondor.apana.org.au \
--cc=kaber@trash.net \
--cc=netdev@vger.kernel.org \
--cc=shemminger@vyatta.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.