io_uring/uring_cmd: cleanup struct io_uring_cmd_data layout

A few spots in uring_cmd assume that the SQEs copied are always at the
start of the structure, and hence mix req->async_data and the struct
itself.

Clean that up and use the proper indices.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: axboe

io_uring/uring_cmd.c

@@ -192,8 +192,8 @@ static int io_uring_cmd_prep_setup(struct io_kiocb *req,
 		return 0;
 	}
 
-	memcpy(req->async_data, sqe, uring_sqe_size(req->ctx));
-	ioucmd->sqe = req->async_data;
+	memcpy(cache->sqes, sqe, uring_sqe_size(req->ctx));
+	ioucmd->sqe = cache->sqes;
 	return 0;
 }
 
@@ -260,7 +260,7 @@ int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags)
 		struct io_uring_cmd_data *cache = req->async_data;
 
 		if (ioucmd->sqe != (void *) cache)
-			memcpy(cache, ioucmd->sqe, uring_sqe_size(req->ctx));
+			memcpy(cache->sqes, ioucmd->sqe, uring_sqe_size(req->ctx));
 		return -EAGAIN;
 	} else if (ret == -EIOCBQUEUED) {
 		return -EIOCBQUEUED;