[PATCH liburing] tests: test CQE ordering on early submission fail

[Pavel Begunkov <asml.silence@gmail.com>]

Check that CQEs of a link comes in the order of submission, even when
a link fails early during submission initial prep.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 test/link.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/test/link.c b/test/link.c
index c89d6b2..fadd0b5 100644
--- a/test/link.c
+++ b/test/link.c
@@ -429,6 +429,53 @@ err:
 	return 1;
 }
 
+static int test_link_fail_ordering(struct io_uring *ring)
+{
+	struct io_uring_cqe *cqe;
+	struct io_uring_sqe *sqe;
+	int ret, i, nr_compl;
+
+	sqe = io_uring_get_sqe(ring);
+	io_uring_prep_nop(sqe);
+	sqe->flags |= IOSQE_IO_LINK;
+	sqe->user_data = 0;
+
+	sqe = io_uring_get_sqe(ring);
+	io_uring_prep_write(sqe, -1, NULL, 100, 0);
+	sqe->flags |= IOSQE_IO_LINK;
+	sqe->user_data = 1;
+
+	sqe = io_uring_get_sqe(ring);
+	io_uring_prep_nop(sqe);
+	sqe->flags |= IOSQE_IO_LINK;
+	sqe->user_data = 2;
+
+	nr_compl = ret = io_uring_submit(ring);
+	/* at least the first nop should have been submitted */
+	if (ret < 1) {
+		fprintf(stderr, "sqe submit failed: %d\n", ret);
+		goto err;
+	}
+
+	for (i = 0; i < nr_compl; i++) {
+		ret = io_uring_wait_cqe(ring, &cqe);
+		if (ret) {
+			fprintf(stderr, "wait completion %d\n", ret);
+			goto err;
+		}
+		if (cqe->user_data != i) {
+			fprintf(stderr, "wrong CQE order, got %i, expected %i\n",
+					(int)cqe->user_data, i);
+			goto err;
+		}
+		io_uring_cqe_seen(ring, cqe);
+	}
+
+	return 0;
+err:
+	return 1;
+}
+
 int main(int argc, char *argv[])
 {
 	struct io_uring ring, poll_ring;
@@ -492,5 +539,11 @@ int main(int argc, char *argv[])
 		return ret;
 	}
 
+	ret = test_link_fail_ordering(&ring);
+	if (ret) {
+		fprintf(stderr, "test_link_fail_ordering last failed\n");
+		return ret;
+	}
+
 	return 0;
 }
-- 
2.24.0