Revert "io_uring: support CQE32 for nop operation"

This reverts commit 2bb04df7.

CQE32 nops were used for debugging and benchmarking but it doesn't
target any real use case. Revert it, we can return it back if someone
finds a good way to use it.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5ff623d84ccb4b3f3b92a3ea41cdcfa612f3d96f.1655224415.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -784,12 +784,6 @@ struct io_msg {
 	u32 len;
 };
 
-struct io_nop {
-	struct file			*file;
-	u64				extra1;
-	u64				extra2;
-};
-
 struct io_async_connect {
 	struct sockaddr_storage		address;
 };
@@ -994,7 +988,6 @@ struct io_kiocb {
 		struct io_msg		msg;
 		struct io_xattr		xattr;
 		struct io_socket	sock;
-		struct io_nop		nop;
 		struct io_uring_cmd	uring_cmd;
 	};
 
@@ -5268,14 +5261,6 @@ static int io_splice(struct io_kiocb *req, unsigned int issue_flags)
 
 static int io_nop_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 {
-	/*
-	 * If the ring is setup with CQE32, relay back addr/addr
-	 */
-	if (req->ctx->flags & IORING_SETUP_CQE32) {
-		req->nop.extra1 = READ_ONCE(sqe->addr);
-		req->nop.extra2 = READ_ONCE(sqe->addr2);
-	}
-
 	return 0;
 }
 
@@ -5296,11 +5281,7 @@ static int io_nop(struct io_kiocb *req, unsigned int issue_flags)
 	}
 
 	cflags = io_put_kbuf(req, issue_flags);
-	if (!(req->ctx->flags & IORING_SETUP_CQE32))
-		__io_req_complete(req, issue_flags, 0, cflags);
-	else
-		__io_req_complete32(req, issue_flags, 0, cflags,
-				    req->nop.extra1, req->nop.extra2);
+	__io_req_complete(req, issue_flags, 0, cflags);
 	return 0;
 }