Merge branch 'for-6.7/io_uring' into for-6.7/block

Merge in io_uring fixes, as the ublk simplifying cancelations and
aborts depend on the two patches from Ming adding cancelation support
for uring_cmd.

* for-6.7/io_uring:
  io_uring/kbuf: Use slab for struct io_buffer objects
  io_uring/kbuf: Allow the full buffer id space for provided buffers
  io_uring/kbuf: Fix check of BID wrapping in provided buffers
  io_uring/rsrc: cleanup io_pin_pages()
  io_uring: cancelable uring_cmd
  io_uring: retain top 8bits of uring_cmd flags for kernel internal use
  io_uring: add IORING_OP_WAITID support
  exit: add internal include file with helpers
  exit: add kernel_waitid_prepare() helper
  exit: move core of do_wait() into helper
  exit: abstract out should_wake helper for child_wait_callback()
  io_uring/rw: add support for IORING_OP_READ_MULTISHOT
  io_uring/rw: mark readv/writev as vectored in the opcode definition
  io_uring/rw: split io_read() into a helper