On 1/28/19 5:34 PM, Jann Horn wrote: > On Tue, Jan 29, 2019 at 1:32 AM Jens Axboe <axboe@xxxxxxxxx> wrote: >> On 1/28/19 5:03 PM, Jens Axboe wrote: >>>> But you only do that teardown on ->release, right? And ->release >>>> doesn't have much to do with the process lifetime. >>> >>> Yes, only on ->relase(). >> >> OK, so I reworked the files struct to just grab it, then we ensure that >> doesn't go away. For mm, it's a bit more tricky. I think the best >> solution here is to add a fops->flush() and check for the process >> exiting its files. If it does, we quiesce the async contexts and prevent >> further use of that mm. We can't just keep holding a reference to the mm >> like we do with the files. >> >> That should solve both cases. > > You still have to hold a reference on the mm though, I think (for > example, because two tasks might be sharing the fd table without > sharing the mm). Yes good point, except we can't hold a reference to it. But I think we can get around this by using an mmu notifier instead. That eliminates the need for ->flush() as well. -- Jens Axboe
