From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jarek Poplawski <jarkao2@gmail.com>
Subject: Re: [PATCH] net: deadlock during net device unregistration - V2
Date: Thu, 2 Oct 2008 01:31:52 +0200
Message-ID: <20081001233152.GA2411@ami.dom.local>
References: <48E24341.5050609@bull.net> <20081001.025935.257260146.davem@davemloft.net> <48E34C82.2040306@fr.ibm.com> <20081001.031243.255655293.davem@davemloft.net> <20081001141432.470106980@theryb.frec.bull.fr> <20081001194825.GA2520@ami.dom.local> <48E3E64E.50106@fr.ibm.com>
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Cc: Benjamin Thery <benjamin.thery@bull.net>,
	"David S. Miller" <davem@davemloft.net>,
	netdev <netdev@vger.kernel.org>
To: Daniel Lezcano <dlezcano@fr.ibm.com>
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On Wed, Oct 01, 2008 at 11:06:22PM +0200, Daniel Lezcano wrote:
> Jarek Poplawski wrote:
>> On Wed, Oct 01, 2008 at 04:14:35PM +0200, Benjamin Thery wrote:
...
>>> --- net-next-2.6.orig/net/core/dst.c
>>> +++ net-next-2.6/net/core/dst.c
>>> @@ -328,6 +328,10 @@ static int dst_dev_event(struct notifier
>>>  			dst_ifdown(dst, dev, event != NETDEV_DOWN);
>>>  		}
>>>  		mutex_unlock(&dst_gc_mutex);
>>> +
>>> +		if (event == NETDEV_UNREGISTER &&
>>> +		    cancel_delayed_work(&dst_gc_work))
>>> +			dst_gc_task(&dst_gc_work.work);
>>
>> Hmm... It seems this shouldn't work yet: cancel_delayed_work() can only
>> kill this while on timer, but not when queued and maybe blocked already.

Hmm#2... Then maybe something like this?:

		if (event == NETDEV_UNREGISTER &&
	    	    (cancel_delayed_work(&dst_gc_work) ||
		     delayed_work_pending(&dst_gc_work)))
			dst_gc_task(&dst_gc_work.work);


Jarek P.