[PATCH v2] liburing: Add regression test case for link with drain

[Jackie Liu <liuyun01@kylinos.cn>]

Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
---
V2:                                                                                                                                                                                                                                                                             - Fix loop iterators                                                                                                                                                                                                                                                           - close fd  

 test/Makefile     |   4 +-
 test/link_drain.c | 123 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 125 insertions(+), 2 deletions(-)
 create mode 100644 test/link_drain.c

diff --git a/test/Makefile b/test/Makefile
index a3a2556..ddbcc6a 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -9,7 +9,7 @@ all_targets += poll poll-cancel ring-leak fsync io_uring_setup io_uring_register
 		sq-space_left stdout cq-ready cq-peek-batch file-register \
 		cq-size 8a9973408177-test a0908ae19763-test 232c93d07b74-test \
 		socket-rw accept timeout-overflow defer read-write io-cancel \
-		link-timeout cq-overflow
+		link-timeout cq-overflow link_drain
 
 include ../Makefile.quiet
 
@@ -26,7 +26,7 @@ test_srcs := poll.c poll-cancel.c ring-leak.c fsync.c io_uring_setup.c \
 	cq-peek-batch.c file-register.c cq-size.c 8a9973408177-test.c \
 	a0908ae19763-test.c 232c93d07b74-test.c socket-rw.c accept.c \
 	timeout-overflow.c defer.c read-write.c io-cancel.c link-timeout.c \
-	cq-overflow.c
+	cq-overflow.c link_drain.c
 
 test_objs := $(patsubst %.c,%.ol,$(test_srcs))
 
diff --git a/test/link_drain.c b/test/link_drain.c
new file mode 100644
index 0000000..c192a5d
--- /dev/null
+++ b/test/link_drain.c
@@ -0,0 +1,123 @@
+/*
+ * Description: test io_uring link io with drain io
+ *
+ */
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+
+#include "liburing.h"
+
+char expect[3][5] = {
+	{ 0, 1, 2, 3, 4 },
+	{ 0, 1, 2, 4, 3 },
+	{ 0, 1, 4, 2, 3 }
+};
+
+static int test_link_drain(struct io_uring *ring)
+{
+	struct io_uring_cqe *cqe;
+	struct io_uring_sqe *sqe[5];
+	struct iovec iovecs;
+	int i, fd, ret;
+	off_t off = 0;
+	char data[5] = {0};
+
+	fd = open("testfile", O_WRONLY | O_CREAT, 0644);
+	if (fd < 0) {
+		perror("open");
+		return 1;
+	}
+
+	iovecs.iov_base = malloc(4096);
+	iovecs.iov_len = 4096;
+
+	for (i = 0; i < 5; i++) {
+		sqe[i] = io_uring_get_sqe(ring);
+		if (!sqe[i]) {
+			printf("get sqe failed\n");
+			goto err;
+		}
+	}
+
+	/* normal heavy io */
+	io_uring_prep_writev(sqe[0], fd, &iovecs, 1, off);
+	sqe[0]->user_data = 0;
+
+	/* link io */
+	io_uring_prep_nop(sqe[1]);
+	sqe[1]->flags |= IOSQE_IO_LINK;
+	sqe[1]->user_data = 1;
+
+	/* link drain io */
+	io_uring_prep_nop(sqe[2]);
+	sqe[2]->flags |= (IOSQE_IO_LINK | IOSQE_IO_DRAIN);
+	sqe[2]->user_data = 2;
+
+	/* link io */
+	io_uring_prep_nop(sqe[3]);
+	sqe[3]->user_data = 3;
+
+	/* normal nop io */
+	io_uring_prep_nop(sqe[4]);
+	sqe[4]->user_data = 4;
+
+	ret = io_uring_submit(ring);
+	if (ret < 5) {
+		printf("Submitted only %d\n", ret);
+		goto err;
+	} else if (ret < 0) {
+		printf("sqe submit failed\n");
+		goto err;
+	}
+
+	for (i = 0; i < 5; i++) {
+		ret = io_uring_wait_cqe(ring, &cqe);
+		if (ret < 0) {
+			printf("child: wait completion %d\n", ret);
+			goto err;
+		}
+
+		data[i] = cqe->user_data;
+		io_uring_cqe_seen(ring, cqe);
+	}
+
+	free(iovecs.iov_base);
+	close(fd);
+
+	for (i = 0; i < 3; i++) {
+		if (memcmp(data, expect[i], 5) == 0)
+			break;
+	}
+	if (i == 3)
+		goto err;
+
+	unlink("testfile");
+	return 0;
+err:
+	unlink("testfile");
+	return 1;
+}
+
+int main(int argc, char *argv[])
+{
+	struct io_uring ring;
+	int i, ret;
+
+	ret = io_uring_queue_init(5, &ring, 0);
+	if (ret) {
+		printf("ring setup failed\n");
+		return 1;
+	}
+
+	for (i = 0; i < 1000; i++)
+		ret |= test_link_drain(&ring);
+
+	if (ret)
+		return ret;
+
+	return 0;
+}
-- 
2.7.4