Potential corner case in release 5.8

[Ryan Sharpelletti <sharpelletti@google.com>]

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