Merge tag 'for-6.12/io_uring-20240922' of git://git.kernel.dk/linux

Pull more io_uring updates from Jens Axboe:
 "Mostly just a set of fixes in here, or little changes that didn't get
  included in the initial pull request. This contains:

   - Move the SQPOLL napi polling outside the submission lock (Olivier)

   - Rename of the "copy buffers" API that got added in the 6.12 merge
     window. There's really no copying going on, it's just referencing
     the buffers. After a bit of consideration, decided that it was
     better to simply rename this to avoid potential confusion (me)

   - Shrink struct io_mapped_ubuf from 48 to 32 bytes, by changing it to
     start + len tracking rather than having start / end in there, and
     by removing the caching of folio_mask when we can just calculate it
     from folio_shift when we need it (me)

   - Fixes for the SQPOLL affinity checking (me, Felix)

   - Fix for how cqring waiting checks for the presence of task_work.
     Just check it directly rather than check for a specific
     notification mechanism (me)

   - Tweak to how request linking is represented in tracing (me)

   - Fix a syzbot report that deliberately sets up a huge list of
     overflow entries, and then hits rcu stalls when flushing this list.
     Just check for the need to preempt, and drop/reacquire locks in the
     loop. There's no state maintained over the loop itself, and each
     entry is yanked from head-of-list (me)"

* tag 'for-6.12/io_uring-20240922' of git://git.kernel.dk/linux:
  io_uring: check if we need to reschedule during overflow flush
  io_uring: improve request linking trace
  io_uring: check for presence of task_work rather than TIF_NOTIFY_SIGNAL
  io_uring/sqpoll: do the napi busy poll outside the submission block
  io_uring: clean up a type in io_uring_register_get_file()
  io_uring/sqpoll: do not put cpumask on stack
  io_uring/sqpoll: retain test for whether the CPU is valid
  io_uring/rsrc: change ubuf->ubuf_end to length tracking
  io_uring/rsrc: get rid of io_mapped_ubuf->folio_mask
  io_uring: rename "copy buffers" to "clone buffers"

include/uapi/linux/io_uring.h

@@ -609,8 +609,8 @@ enum io_uring_register_op {
 
 	IORING_REGISTER_CLOCK			= 29,
 
-	/* copy registered buffers from source ring to current ring */
-	IORING_REGISTER_COPY_BUFFERS		= 30,
+	/* clone registered buffers from source ring to current ring */
+	IORING_REGISTER_CLONE_BUFFERS		= 30,
 
 	/* this goes last */
 	IORING_REGISTER_LAST,
@@ -701,7 +701,7 @@ enum {
 	IORING_REGISTER_SRC_REGISTERED = 1,
 };
 
-struct io_uring_copy_buffers {
+struct io_uring_clone_buffers {
 	__u32	src_fd;
 	__u32	flags;
 	__u32	pad[6];