io_uring: hide caches sqes from drivers

There is now an io_uring private part of cmd async_data, move saved sqe
into it. Drivers are accessing it via struct io_uring_cmd::cmd.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/ecbe078dd57acefdbc4366d083327086c0879378.1743357121.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

include/linux/io_uring/cmd.h

@@ -21,7 +21,6 @@ struct io_uring_cmd {
 
 struct io_uring_cmd_data {
 	void			*op_data;
-	struct io_uring_sqe	sqes[2];
 };
 
 static inline const void *io_uring_sqe_cmd(const struct io_uring_sqe *sqe)

io_uring/uring_cmd.c

@@ -205,8 +205,8 @@ static int io_uring_cmd_prep_setup(struct io_kiocb *req,
 	 * that it doesn't read in per-op data, play it safe and ensure that
 	 * any SQE data is stable beyond prep. This can later get relaxed.
 	 */
-	memcpy(ac->data.sqes, sqe, uring_sqe_size(req->ctx));
-	ioucmd->sqe = ac->data.sqes;
+	memcpy(ac->sqes, sqe, uring_sqe_size(req->ctx));
+	ioucmd->sqe = ac->sqes;
 	return 0;
 }
 

io_uring/uring_cmd.h

@@ -6,6 +6,7 @@
 struct io_async_cmd {
 	struct io_uring_cmd_data	data;
 	struct iou_vec			vec;
+	struct io_uring_sqe		sqes[2];
 };
 
 int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags);