[PATCH liburing v3 5/5] test/io_uring_passthrough: add test case for poll IO

[Ankit Kumar <ankit.kumar@samsung.com>]

For uring passthrough add test case for poll IO completion.
If poll IO is not supported return success.

Tested-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Ankit Kumar <ankit.kumar@samsung.com>
---
 test/io_uring_passthrough.c | 76 +++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)

diff --git a/test/io_uring_passthrough.c b/test/io_uring_passthrough.c
index 03043b7..d4a2169 100644
--- a/test/io_uring_passthrough.c
+++ b/test/io_uring_passthrough.c
@@ -10,6 +10,7 @@
 
 #include "helpers.h"
 #include "liburing.h"
+#include "../src/syscall.h"
 #include "nvme.h"
 
 #define FILE_SIZE	(256 * 1024)
@@ -278,6 +279,75 @@ static int test_io(const char *file, int tc, int read, int sqthread,
 	return ret;
 }
 
+extern int __io_uring_flush_sq(struct io_uring *ring);
+
+/*
+ * if we are polling io_uring_submit needs to always enter the
+ * kernel to fetch events
+ */
+static int test_io_uring_submit_enters(const char *file)
+{
+	struct io_uring ring;
+	int fd, i, ret, ring_flags, open_flags;
+	unsigned head;
+	struct io_uring_cqe *cqe;
+
+	ring_flags = IORING_SETUP_IOPOLL;
+	ring_flags |= IORING_SETUP_SQE128;
+	ring_flags |= IORING_SETUP_CQE32;
+
+	ret = io_uring_queue_init(64, &ring, ring_flags);
+	if (ret) {
+		fprintf(stderr, "ring create failed: %d\n", ret);
+		return 1;
+	}
+
+	open_flags = O_WRONLY;
+	fd = open(file, open_flags);
+	if (fd < 0) {
+		perror("file open");
+		goto err;
+	}
+
+	for (i = 0; i < BUFFERS; i++) {
+		struct io_uring_sqe *sqe;
+		off_t offset = BS * (rand() % BUFFERS);
+
+		sqe = io_uring_get_sqe(&ring);
+		io_uring_prep_writev(sqe, fd, &vecs[i], 1, offset);
+		sqe->user_data = 1;
+	}
+
+	/* submit manually to avoid adding IORING_ENTER_GETEVENTS */
+	ret = __sys_io_uring_enter(ring.ring_fd, __io_uring_flush_sq(&ring), 0,
+						0, NULL);
+	if (ret < 0)
+		goto err;
+
+	for (i = 0; i < 500; i++) {
+		ret = io_uring_submit(&ring);
+		if (ret != 0) {
+			fprintf(stderr, "still had %d sqes to submit, this is unexpected", ret);
+			goto err;
+		}
+
+		io_uring_for_each_cqe(&ring, head, cqe) {
+			if (cqe->res == -EOPNOTSUPP)
+				fprintf(stdout, "Device doesn't support polled IO\n");
+			goto ok;
+		}
+		usleep(10000);
+	}
+err:
+	ret = 1;
+	if (fd != -1)
+		close(fd);
+
+ok:
+	io_uring_queue_exit(&ring);
+	return ret;
+}
+
 int main(int argc, char *argv[])
 {
 	int i, ret;
@@ -308,6 +378,12 @@ int main(int argc, char *argv[])
 		}
 	}
 
+	ret = test_io_uring_submit_enters(fname);
+	if (ret) {
+		fprintf(stderr, "test_io_uring_submit_enters failed\n");
+		goto err;
+	}
+
 	return T_EXIT_PASS;
 err:
 	return T_EXIT_FAIL;
-- 
2.17.1