Merge branch 'for-5.8/io_uring' into async-buffered.5

Merge branch 'for-5.8/io_uring' into async-buffered.5

* for-5.8/io_uring: (22 commits)
  io_uring: get rid of manual punting in io_close
  io_uring: separate DRAIN flushing into a cold path
  io_uring: don't re-read sqe->off in timeout_prep()
  io_uring: simplify io_timeout locking
  io_uring: fix flush req->refs underflow
  io_uring: don't submit sqes when ctx->refs is dying
  io_uring: async task poll trigger cleanup
  io_uring: add tee(2) support
  splice: export do_tee()
  io_uring: don't repeat valid flag list
  io_uring: rename io_file_put()
  io_uring: remove req->needs_fixed_files
  io_uring: cleanup io_poll_remove_one() logic
  io_uring: file registration list and lock optimization
  io_uring: add IORING_CQ_EVENTFD_DISABLED to the CQ ring flags
  io_uring: add 'cq_flags' field for the CQ ring
  io_uring: allow POLL_ADD with double poll_wait() users
  io_uring: batch reap of dead file registrations
  io_uring: name sq thread and ref completions
  io_uring: remove duplicate semicolon at the end of line
  ...