Merge tag 'for-6.16/io_uring-20250523' of git://git.kernel.dk/linux

Pull io_uring updates from Jens Axboe:

 - Avoid indirect function calls in io-wq for executing and freeing
   work.

   The design of io-wq is such that it can be a generic mechanism, but
   as it's just used by io_uring now, may as well avoid these indirect
   calls

 - Clean up registered buffers for networking

 - Add support for IORING_OP_PIPE. Pretty straight forward, allows
   creating pipes with io_uring, particularly useful for having these be
   instantiated as direct descriptors

 - Clean up the coalescing support fore registered buffers

 - Add support for multiple interface queues for zero-copy rx
   networking. As this feature was merged for 6.15 it supported just a
   single ifq per ring

 - Clean up the eventfd support

 - Add dma-buf support to zero-copy rx

 - Clean up and improving the request draining support

 - Clean up provided buffer support, most notably with an eye toward
   making the legacy support less intrusive

 - Minor fdinfo cleanups, dropping support for dumping what credentials
   are registered

 - Improve support for overflow CQE handling, getting rid of GFP_ATOMIC
   for allocating overflow entries where possible

 - Improve detection of cases where io-wq doesn't need to spawn a new
   worker unnecessarily

 - Various little cleanups

* tag 'for-6.16/io_uring-20250523' of git://git.kernel.dk/linux: (59 commits)
  io_uring/cmd: warn on reg buf imports by ineligible cmds
  io_uring/io-wq: only create a new worker if it can make progress
  io_uring/io-wq: ignore non-busy worker going to sleep
  io_uring/io-wq: move hash helpers to the top
  trace/io_uring: fix io_uring_local_work_run ctx documentation
  io_uring: finish IOU_OK -> IOU_COMPLETE transition
  io_uring: add new helpers for posting overflows
  io_uring: pass in struct io_big_cqe to io_alloc_ocqe()
  io_uring: make io_alloc_ocqe() take a struct io_cqe pointer
  io_uring: split alloc and add of overflow
  io_uring: open code io_req_cqe_overflow()
  io_uring/fdinfo: get rid of dumping credentials
  io_uring/fdinfo: only compile if CONFIG_PROC_FS is set
  io_uring/kbuf: unify legacy buf provision and removal
  io_uring/kbuf: refactor __io_remove_buffers
  io_uring/kbuf: don't compute size twice on prep
  io_uring/kbuf: drop extra vars in io_register_pbuf_ring
  io_uring/kbuf: use mem_is_zero()
  io_uring/kbuf: account ring io_buffer_list memory
  io_uring: drain based on allocates reqs
  ...

include/uapi/linux/io_uring.h

@@ -73,6 +73,7 @@ struct io_uring_sqe {
 		__u32		futex_flags;
 		__u32		install_fd_flags;
 		__u32		nop_flags;
+		__u32		pipe_flags;
 	};
 	__u64	user_data;	/* data to be passed back at completion time */
 	/* pack this to avoid bogus arm OABI complaints */
@@ -287,6 +288,7 @@ enum io_uring_op {
 	IORING_OP_EPOLL_WAIT,
 	IORING_OP_READV_FIXED,
 	IORING_OP_WRITEV_FIXED,
+	IORING_OP_PIPE,
 
 	/* this goes last, obviously */
 	IORING_OP_LAST,
@@ -992,12 +994,16 @@ struct io_uring_zcrx_offsets {
 	__u64	__resv[2];
 };
 
+enum io_uring_zcrx_area_flags {
+	IORING_ZCRX_AREA_DMABUF		= 1,
+};
+
 struct io_uring_zcrx_area_reg {
 	__u64	addr;
 	__u64	len;
 	__u64	rq_area_token;
 	__u32	flags;
-	__u32	__resv1;
+	__u32	dmabuf_fd;
 	__u64	__resv2[2];
 };