[PATCH liburing] test: add sq-poll-kthread test case

[Stefano Garzarella]

sq-poll-kthread tests if the 'io_uring-sq' kthread is stopped
when the userspace process ended with or without closing the
io_uring fd.

Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
---
 .gitignore             |   1 +
 test/Makefile          |   4 +-
 test/sq-poll-kthread.c | 165 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 168 insertions(+), 2 deletions(-)
 create mode 100644 test/sq-poll-kthread.c

diff --git a/.gitignore b/.gitignore
index 1ab4075..9f85a5f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -75,6 +75,7 @@
 /test/short-read
 /test/socket-rw
 /test/sq-full
+/test/sq-poll-kthread
 /test/sq-space_left
 /test/statx
 /test/stdout
diff --git a/test/Makefile b/test/Makefile
index cf91011..09c7aa2 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -20,7 +20,7 @@ all_targets += poll poll-cancel ring-leak fsync io_uring_setup io_uring_register
 		connect 7ad0e4b2f83c-test submit-reuse fallocate open-close \
 		file-update statx accept-reuse poll-v-poll fadvise madvise \
 		short-read openat2 probe shared-wq personality eventfd \
-		send_recv eventfd-ring across-fork
+		send_recv eventfd-ring across-fork sq-poll-kthread
 
 include ../Makefile.quiet
 
@@ -47,7 +47,7 @@ test_srcs := poll.c poll-cancel.c ring-leak.c fsync.c io_uring_setup.c \
 	7ad0e4b2f83c-test.c submit-reuse.c fallocate.c open-close.c \
 	file-update.c statx.c accept-reuse.c poll-v-poll.c fadvise.c \
 	madvise.c short-read.c openat2.c probe.c shared-wq.c \
-	personality.c eventfd.c eventfd-ring.c across-fork.c
+	personality.c eventfd.c eventfd-ring.c across-fork.c sq-poll-kthread.c
 
 test_objs := $(patsubst %.c,%.ol,$(test_srcs))
 
diff --git a/test/sq-poll-kthread.c b/test/sq-poll-kthread.c
new file mode 100644
index 0000000..d53605c
--- /dev/null
+++ b/test/sq-poll-kthread.c
@@ -0,0 +1,165 @@
+/*
+ * Description: test if io_uring SQ poll kthread is stopped when the userspace
+ *              process ended with or without closing the io_uring fd
+ *
+ */
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include <sys/poll.h>
+#include <sys/wait.h>
+#include <sys/epoll.h>
+
+#include "liburing.h"
+
+#define SQ_THREAD_IDLE  2000
+#define BUF_SIZE        128
+#define KTHREAD_NAME    "io_uring-sq"
+
+enum {
+	TEST_OK = 0,
+	TEST_SKIPPED = 1,
+	TEST_FAILED = 2,
+};
+
+static int do_test_sq_poll_kthread_stopped(bool do_exit)
+{
+	int ret = 0, pipe1[2];
+	struct io_uring_params param;
+	struct io_uring ring;
+	struct io_uring_sqe *sqe;
+	struct io_uring_cqe *cqe;
+	uint8_t buf[BUF_SIZE];
+	struct iovec iov;
+
+	if (geteuid()) {
+		fprintf(stderr, "sqpoll requires root!\n");
+		return TEST_SKIPPED;
+	}
+
+	if (pipe(pipe1) != 0) {
+		perror("pipe");
+		return TEST_FAILED;
+	}
+
+	memset(&param, 0, sizeof(param));
+
+	param.flags |= IORING_SETUP_SQPOLL;
+	param.sq_thread_idle = SQ_THREAD_IDLE;
+
+	ret = io_uring_queue_init_params(16, &ring, &param);
+	if (ret) {
+		fprintf(stderr, "ring setup failed\n");
+		ret = TEST_FAILED;
+		goto err_pipe;
+	}
+
+	ret = io_uring_register_files(&ring, &pipe1[1], 1);
+	if (ret) {
+		fprintf(stderr, "file reg failed: %d\n", ret);
+		ret = TEST_FAILED;
+		goto err_uring;
+	}
+
+	iov.iov_base = buf;
+	iov.iov_len = BUF_SIZE;
+
+	sqe = io_uring_get_sqe(&ring);
+	if (!sqe) {
+		fprintf(stderr, "io_uring_get_sqe failed\n");
+		ret = TEST_FAILED;
+		goto err_uring;
+	}
+
+	io_uring_prep_writev(sqe, 0, &iov, 1, 0);
+	sqe->flags |= IOSQE_FIXED_FILE;
+
+	ret = io_uring_submit(&ring);
+	if (ret < 0) {
+		fprintf(stderr, "io_uring_submit failed - ret: %d\n",
+			ret);
+		ret = TEST_FAILED;
+		goto err_uring;
+	}
+
+	ret = io_uring_wait_cqe(&ring, &cqe);
+	if (ret < 0) {
+		fprintf(stderr, "io_uring_wait_cqe - ret: %d\n",
+			ret);
+		ret = TEST_FAILED;
+		goto err_uring;
+	}
+
+	if (cqe->res != BUF_SIZE) {
+		fprintf(stderr, "unexpected cqe->res %d [expected %d]\n",
+			cqe->res, BUF_SIZE);
+		ret = TEST_FAILED;
+		goto err_uring;
+
+	}
+
+	io_uring_cqe_seen(&ring, cqe);
+
+	ret = TEST_OK;
+
+err_uring:
+	if (do_exit)
+		io_uring_queue_exit(&ring);
+err_pipe:
+	close(pipe1[0]);
+	close(pipe1[1]);
+
+	return ret;
+}
+
+int test_sq_poll_kthread_stopped(bool do_exit) {
+	pid_t pid;
+	int status = 0;
+
+	pid = fork();
+
+	if (pid == 0) {
+		int ret = do_test_sq_poll_kthread_stopped(do_exit);
+		exit(ret);
+	}
+
+	pid = wait(&status);
+	if (status != 0)
+		return WEXITSTATUS(status);
+
+	if (system("ps --ppid 2 | grep " KTHREAD_NAME) == 0) {
+		fprintf(stderr, "%s kthread still running!\n", KTHREAD_NAME);
+		return TEST_FAILED;
+	}
+
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	int ret;
+
+	ret = test_sq_poll_kthread_stopped(true);
+	if (ret == TEST_SKIPPED) {
+		printf("test_sq_poll_kthread_stopped_exit: skipped\n");
+	} else if (ret == TEST_FAILED) {
+		fprintf(stderr, "test_sq_poll_kthread_stopped_exit failed\n");
+		return ret;
+	}
+
+	ret = test_sq_poll_kthread_stopped(false);
+	if (ret == TEST_SKIPPED) {
+		printf("test_sq_poll_kthread_stopped_noexit: skipped\n");
+	} else if (ret == TEST_FAILED) {
+		fprintf(stderr, "test_sq_poll_kthread_stopped_noexit failed\n");
+		return ret;
+	}
+
+	return 0;
+}
-- 
2.24.1