Messages in this thread | | | Subject | Re: drm_vm.c:drm_mmap: possible circular locking dependency detected | From | (Eric W. Biederman) | Date | Sat, 02 Jan 2010 21:38:05 -0800 |
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Tejun Heo <tj@kernel.org> writes:
> It's interesting that the above cases arn't common drivers. AFAICS, > the problem cases would usually be cases like above where the user is > a rather complex software entity or drivers which implement some form > of self detaching via sysfs. For the former group, I agree that > splitting deleting and draining (or simply skipping the draining part > or active reference counting both of which basically achieve the same > thing) would be an easy way out as it would be generally easy to leave > the data structures dangling till the references go away. > > How about simply introducing an interface to mark sysfs nodes which > don't require active reference counting and using them on those nodes?
That might work. However it does not seem to address the case of bond_sysfs, especially with someone doing rmmod bonding.
I think the brainstorm is on the right track. I think we just need to look at a few more cases in depth so that we can see a pattern and generalize what can be done.
Eric
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