[PATCH 0/4] fix SQPOLL and exit races

[Pavel Begunkov <asml.silence@gmail.com>]

The series prevents submissions from SQPOLL thread when sqo_task is
getting killed (or exec()ed). That should solve races introduced by a
patch that allowed task_works during cancellation.

Jens, IIRC you said that io_rw_reissue() is called only during
submission, right? 4/4 depends on that, so 1/4 should help to catch any
misbehaviour. I reduced nr_requests but wasn't able to trigger
io_resubmit_prep() for iopoll or not. What was the trick again?

4/4 is actually fairly simple, but safety measures and comments make it
to bloat. The overhead is pretty negligible, and it allows to kill more,
but that's for-next.

Pavel Begunkov (4):
  io_uring: io_rw_reissue lockdep annotations
  io_uring: inline io_uring_attempt_task_drop()
  io_uring: add warn_once for io_uring_flush()
  io_uring: stop SQPOLL submit on creator's death

 fs/io_uring.c | 97 +++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 71 insertions(+), 26 deletions(-)

-- 
2.24.0