Pull io_uring updates from Jens Axboe:

 - Multi-queue iopoll improvement (Fam)

 - Allow configurable io-wq CPU masks (me)

 - renameat/linkat tightening (me)

 - poll re-arm improvement (Olivier)

 - SQPOLL race fix (Olivier)

 - Cancelation unification (Pavel)

 - SQPOLL cleanups (Pavel)

 - Enable file backed buffers for shmem/memfd (Pavel)

 - A ton of cleanups and performance improvements (Pavel)

 - Followup and misc fixes (Colin, Fam, Hao, Olivier)

* tag 'for-5.14/io_uring-2021-06-30' of git://git.kernel.dk/linux-block: (83 commits)
  io_uring: code clean for kiocb_done()
  io_uring: spin in iopoll() only when reqs are in a single queue
  io_uring: pre-initialise some of req fields
  io_uring: refactor io_submit_flush_completions
  io_uring: optimise hot path restricted checks
  io_uring: remove not needed PF_EXITING check
  io_uring: mainstream sqpoll task_work running
  io_uring: refactor io_arm_poll_handler()
  io_uring: reduce latency by reissueing the operation
  io_uring: add IOPOLL and reserved field checks to IORING_OP_UNLINKAT
  io_uring: add IOPOLL and reserved field checks to IORING_OP_RENAMEAT
  io_uring: refactor io_openat2()
  io_uring: simplify struct io_uring_sqe layout
  io_uring: update sqe layout build checks
  io_uring: fix code style problems
  io_uring: refactor io_sq_thread()
  io_uring: don't change sqpoll creds if not needed
  io_uring: Create define to modify a SQPOLL parameter
  io_uring: Fix race condition when sqp thread goes to sleep
  io_uring: improve in tctx_task_work() resubmission
  ...