Re: [RFD driver-core] Lifetime problems of the current driver model

Tejun Heo
2007-03-30T13:20:00Z

Cornelia Huck wrote:
> On Fri, 30 Mar 2007 18:43:02 +0900,
> Tejun Heo <htejun@gmail.com> wrote:
>
>> One way to solve this problem is to subordinate lifetime rule #b to
>> rule #c. Each kobject points to its owning module such that grabbing
>> a kobject automatically grabs the module. The problem with this
>> approach is that it requires wide update and makes kobject_get
>> heavier.
>
> Shouldn't getting/putting the module refcount be solely done in
> kobject.c? Grab the module reference when the kobject is created and
> release the module reference in kobject_cleanup() after the release
> function has been called. This doesn't make kobject_get() heavier, and
> it ensures we don't delete the module until after the last kobject it is
> supposed to clean up has been released.

If we do that, we wouldn't be able to unload a module if there is any
kobject referencing it even when the node has no openers, so no easy way
out there. :-(

--
tejun