Re: v3.7: Unloading ib_ipoib triggers circular locking dependency complaint

[Or Gerlitz <ogerlitz-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>]

On 12/03/2013 15:57, Bart Van Assche wrote:
> On 11/26/12 09:00, Or Gerlitz wrote:
>> On Fri, Nov 23, 2012 at 2:10 PM, Bart Van Assche <bvanassche-HInyCGIudOg@public.gmane.org> 
>> wrote:
>>> Apparently unloading the ib_ipoib kernel module triggers a circular 
>>> locking
>>> dependency complaint. Has anyone already been looking into this ?
>>
>> Yes, I see that this happens here e.g when doing hot-unplug to the
>> underlying HW driver, seems related to the ipoib rtnl ops patches I
>> pushed to 3.7 -- will look into this, thanks for bringing this up.
>> Does anyone has an idea where the "s_active" lock is defined and what
>> is its role?
>
> (replying to an e-mail from a few months ago) I still see this with 
> kernel 3.8.0. This warning probably means that sysfs_remove_dir() is 
> invoked with the rtnl lock held. If so I think that this can trigger a 
> deadlock during module removal.

Yep, something goes wrong w.r.t to the interaction with sysfs and rtnl, 
at some point very similar lockdep traces were sent to netdev from other 
drivers and a generic solution was suggested, but I am not sure where 
this has landed, see

http://marc.info/?l=linux-kernel&m=135293378513907&w=2
http://marc.info/?l=linux-netdev&m=135438302622434&w=2

Or.
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