[PATCHSET v3] io_uring fixes for 5.5-rc3

[Jens Axboe <axboe@kernel.dk>]

This should be final for 5.5-rc3, I've run this through all the
testing and we're solid. The main changes since v2 are:

- Add Pavel's patch for the wait-and-submit issue
- Drop the ->free_req() addition. We can do this without adding
  extra io_async_ctx storage.
- Fixed a missing check for CONFIG_NET

I think this improves it all around, and it makes me more comfortable
with the persistent state. There's three patches that deal with
poll add/remove, cancel async, and timeout remove. Those are the three
commands we still missed that need to retain state across a deferral,
and then a patch that stuffs sqe->opcode in a io_kiocb hole, and
ensures we assign ->opcode and ->user_data when we retrieve the SQE.

Lastly, a patch that adds a warning about new commands that don't
have a prep handler. We need that for ANY command that reads sqe
fields, which is all of them obviously except NOP.

 fs/io-wq.c    |   2 +-
 fs/io-wq.h    |   8 +-
 fs/io_uring.c | 703 ++++++++++++++++++++++++++++++++++----------------
 3 files changed, 485 insertions(+), 228 deletions(-)

-- 
Jens Axboe