Merge branch 'for-6.15/io_uring' into for-6.15/io_uring-epoll-wait

* for-6.15/io_uring: (30 commits)
  io_uring: use lockless_cq flag in io_req_complete_post()
  io_uring: pass struct io_tw_state by value
  io_uring: introduce type alias for io_tw_state
  io_uring/rsrc: avoid NULL check in io_put_rsrc_node()
  io_uring: pass ctx instead of req to io_init_req_drain()
  io_uring: use IO_REQ_LINK_FLAGS more
  io_uring/net: improve recv bundles
  io_uring/waitid: use generic io_cancel_remove() helper
  io_uring/futex: use generic io_cancel_remove() helper
  io_uring/cancel: add generic cancel helper
  io_uring/waitid: convert to io_cancel_remove_all()
  io_uring/futex: convert to io_cancel_remove_all()
  io_uring/cancel: add generic remove_all helper
  io_uring/kbuf: uninline __io_put_kbufs
  io_uring/kbuf: introduce io_kbuf_drop_legacy()
  io_uring/kbuf: open code __io_put_kbuf()
  io_uring/kbuf: remove legacy kbuf caching
  io_uring/kbuf: simplify __io_put_kbuf
  io_uring/kbuf: move locking into io_kbuf_drop()
  io_uring/kbuf: remove legacy kbuf kmem cache
  ...