Re: Potential corner case in release 5.8

[Ryan Sharpelletti <sharpelletti@google.com>]

Hi,

I am following up on the above, do you know where the associated
mmdrop might be called?

Thanks,
Ryan



On Fri, Mar 5, 2021 at 2:07 PM Ryan Sharpelletti
<sharpelletti@google.com> wrote:
>
> Hi,
>
> I suspect there is a corner case for io_uring in release 5.8.
>
> Can you please explain where the associated mmdrop/kthread_unuse_mm
> calls for io_sq_thread_acquire_mm in io_init_req(...) are?
> Specifically, what would happen if there was an error after calling
> io_sq_thread_acquire_mm (for example, the -EINVAL a few lines after)?
>
> From what I can understand, it looks like the kthread_unuse_mm and
> mmput might be handled in the call to io_sq_thread_acquire_mm in
> io_sq_thread. However, I am not seeing where mmdrop might be called.
>
> Thanks,
> Ryan