[PATCH liburing v3 06/11] add a defer-taskrun test

[Dylan Yudaken <dylany@fb.com>]

Add a test specifically for IORING_SETUP_DEFER_TASKRUN

Signed-off-by: Dylan Yudaken <dylany@fb.com>
---
 test/Makefile        |   1 +
 test/defer-taskrun.c | 333 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 334 insertions(+)
 create mode 100644 test/defer-taskrun.c

diff --git a/test/Makefile b/test/Makefile
index 418c11c95875..78a499a357d7 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -62,6 +62,7 @@ test_srcs := \
 	d4ae271dfaae.c \
 	d77a67ed5f27.c \
 	defer.c \
+	defer-taskrun.c \
 	double-poll-crash.c \
 	drop-submit.c \
 	eeed8b54e0df.c \
diff --git a/test/defer-taskrun.c b/test/defer-taskrun.c
new file mode 100644
index 000000000000..aec8c5d3f223
--- /dev/null
+++ b/test/defer-taskrun.c
@@ -0,0 +1,333 @@
+// SPDX-License-Identifier: MIT
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <error.h>
+#include <sys/eventfd.h>
+#include <signal.h>
+#include <poll.h>
+#include <assert.h>
+#include <pthread.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include "liburing.h"
+#include "test.h"
+#include "helpers.h"
+
+#define EXEC_FILENAME ".defer-taskrun"
+#define EXEC_FILESIZE (1U<<20)
+
+static bool can_read_t(int fd, int time)
+{
+	int ret;
+	struct pollfd p = {
+		.fd = fd,
+		.events = POLLIN,
+	};
+
+	ret = poll(&p, 1, time);
+
+	return ret == 1;
+}
+
+static bool can_read(int fd)
+{
+	return can_read_t(fd, 0);
+}
+
+static void eventfd_clear(int fd)
+{
+	uint64_t val;
+	int ret;
+
+	assert(can_read(fd));
+	ret = read(fd, &val, 8);
+	assert(ret == 8);
+}
+
+static void eventfd_trigger(int fd)
+{
+	uint64_t val = 1;
+	int ret;
+
+	ret = write(fd, &val, sizeof(val));
+	assert(ret == sizeof(val));
+}
+
+#define CHECK(x) if (!(x)) { \
+		fprintf(stderr, "%s:%d %s failed\n", __FILE__, __LINE__, #x); \
+		return -1; }
+
+static int test_eventfd(void)
+{
+	struct io_uring ring;
+	int ret;
+	int fda, fdb;
+	struct io_uring_cqe *cqe;
+
+	ret = io_uring_queue_init(8, &ring, IORING_SETUP_SINGLE_ISSUER |
+					    IORING_SETUP_DEFER_TASKRUN);
+	if (ret)
+		return ret;
+
+	fda = eventfd(0, EFD_NONBLOCK);
+	fdb = eventfd(0, EFD_NONBLOCK);
+
+	CHECK(fda >= 0 && fdb >= 0);
+
+	ret = io_uring_register_eventfd(&ring, fda);
+	if (ret)
+		return ret;
+
+	CHECK(!can_read(fda));
+	CHECK(!can_read(fdb));
+
+	io_uring_prep_poll_add(io_uring_get_sqe(&ring), fdb, POLLIN);
+	io_uring_submit(&ring);
+	CHECK(!can_read(fda)); /* poll should not have completed */
+
+	io_uring_prep_nop(io_uring_get_sqe(&ring));
+	io_uring_submit(&ring);
+	CHECK(can_read(fda)); /* nop should have */
+
+	CHECK(io_uring_peek_cqe(&ring, &cqe) == 0);
+	CHECK(cqe->res == 0);
+	io_uring_cqe_seen(&ring, cqe);
+	eventfd_clear(fda);
+
+	eventfd_trigger(fdb);
+	/* can take time due to rcu_call */
+	CHECK(can_read_t(fda, 1000));
+
+	/* should not have processed the cqe yet */
+	CHECK(io_uring_cq_ready(&ring) == 0);
+
+	io_uring_get_events(&ring);
+	CHECK(io_uring_cq_ready(&ring) == 1);
+
+
+	io_uring_queue_exit(&ring);
+	return 0;
+}
+
+struct thread_data {
+	struct io_uring ring;
+	int efd;
+	char buff[8];
+};
+
+void *thread(void *t)
+{
+	struct thread_data *td = t;
+
+	io_uring_prep_read(io_uring_get_sqe(&td->ring), td->efd, td->buff, sizeof(td->buff), 0);
+	io_uring_submit(&td->ring);
+
+	return NULL;
+}
+
+static int test_thread_shutdown(void)
+{
+	pthread_t t1;
+	int ret;
+	struct thread_data td;
+	struct io_uring_cqe *cqe;
+	uint64_t val = 1;
+
+	ret = io_uring_queue_init(8, &td.ring, IORING_SETUP_SINGLE_ISSUER |
+					       IORING_SETUP_DEFER_TASKRUN);
+	if (ret)
+		return ret;
+
+	/* check that even before submitting we don't get errors */
+	CHECK(io_uring_get_events(&td.ring) == 0);
+
+	td.efd = eventfd(0, 0);
+	CHECK(td.efd >= 0);
+
+	CHECK(pthread_create(&t1, NULL, thread, &td) == 0);
+	CHECK(pthread_join(t1, NULL) == 0);
+
+	CHECK(write(td.efd, &val, sizeof(val)) == sizeof(val));
+	CHECK(io_uring_wait_cqe(&td.ring, &cqe) == -EEXIST);
+
+	close(td.efd);
+	io_uring_queue_exit(&td.ring);
+	return 0;
+}
+
+static int test_exec(const char *filename)
+{
+	int ret;
+	int fd;
+	struct io_uring ring;
+	pid_t fork_pid;
+	static char * const new_argv[] = {"1", "2", "3", NULL};
+	static char * const new_env[] = {NULL};
+	char *buff;
+
+	fork_pid = fork();
+	CHECK(fork_pid >= 0);
+	if (fork_pid > 0) {
+		int wstatus;
+
+		CHECK(waitpid(fork_pid, &wstatus, 0) != (pid_t)-1);
+		if (!WIFEXITED(wstatus) || WEXITSTATUS(wstatus) != T_EXIT_SKIP) {
+			fprintf(stderr, "child failed %i\n", WEXITSTATUS(wstatus));
+			return -1;
+		}
+		return 0;
+	}
+
+	ret = io_uring_queue_init(8, &ring, IORING_SETUP_SINGLE_ISSUER |
+					    IORING_SETUP_DEFER_TASKRUN);
+	if (ret)
+		return ret;
+
+	if (filename) {
+		fd = open(filename, O_RDONLY | O_DIRECT);
+	} else {
+		t_create_file(EXEC_FILENAME, EXEC_FILESIZE);
+		fd = open(EXEC_FILENAME, O_RDONLY | O_DIRECT);
+		unlink(EXEC_FILENAME);
+	}
+	buff = (char*)malloc(EXEC_FILESIZE);
+	CHECK(posix_memalign((void **)&buff, 4096, EXEC_FILESIZE) == 0);
+	CHECK(buff);
+
+	CHECK(fd >= 0);
+	io_uring_prep_read(io_uring_get_sqe(&ring), fd, buff, EXEC_FILESIZE, 0);
+	io_uring_submit(&ring);
+	ret = execve("/proc/self/exe", new_argv, new_env);
+	/* if we get here it failed anyway */
+	fprintf(stderr, "execve failed %d\n", ret);
+	return -1;
+}
+
+static int test_flag(void)
+{
+	struct io_uring ring;
+	int ret;
+	int fd;
+	struct io_uring_cqe *cqe;
+
+	ret = io_uring_queue_init(8, &ring, IORING_SETUP_SINGLE_ISSUER |
+					    IORING_SETUP_DEFER_TASKRUN |
+					    IORING_SETUP_TASKRUN_FLAG);
+	CHECK(!ret);
+
+	fd = eventfd(0, EFD_NONBLOCK);
+	CHECK(fd >= 0);
+
+	io_uring_prep_poll_add(io_uring_get_sqe(&ring), fd, POLLIN);
+	io_uring_submit(&ring);
+	CHECK(!can_read(fd)); /* poll should not have completed */
+
+	eventfd_trigger(fd);
+	CHECK(can_read(fd));
+
+	/* should not have processed the poll cqe yet */
+	CHECK(io_uring_cq_ready(&ring) == 0);
+
+	/* flag should be set */
+	CHECK(IO_URING_READ_ONCE(*ring.sq.kflags) & IORING_SQ_TASKRUN);
+
+	/* Specifically peek, knowing we have only no cqe
+	 * but because the flag is set, liburing should try and get more
+	 */
+	ret = io_uring_peek_cqe(&ring, &cqe);
+
+	CHECK(ret == 0 && cqe);
+	CHECK(!(IO_URING_READ_ONCE(*ring.sq.kflags) & IORING_SQ_TASKRUN));
+
+	close(fd);
+	io_uring_queue_exit(&ring);
+	return 0;
+}
+
+static int test_ring_shutdown(void)
+{
+	struct io_uring ring;
+	int ret;
+	int fd[2];
+	char buff = '\0';
+	char send = 'X';
+
+	ret = io_uring_queue_init(8, &ring, IORING_SETUP_SINGLE_ISSUER |
+					    IORING_SETUP_DEFER_TASKRUN |
+					    IORING_SETUP_TASKRUN_FLAG);
+	CHECK(!ret);
+
+	ret = t_create_socket_pair(fd, true);
+	CHECK(!ret);
+
+	io_uring_prep_recv(io_uring_get_sqe(&ring), fd[0], &buff, 1, 0);
+	io_uring_submit(&ring);
+
+	ret = write(fd[1], &send, 1);
+	CHECK(ret == 1);
+
+	/* should not have processed the poll cqe yet */
+	CHECK(io_uring_cq_ready(&ring) == 0);
+	io_uring_queue_exit(&ring);
+
+	/* task work should have been processed by now */
+	CHECK(buff = 'X');
+
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	int ret;
+	const char *filename = NULL;
+
+	if (argc > 2)
+		return T_EXIT_SKIP;
+	if (argc == 2) {
+		/* This test exposes interesting behaviour with a null-blk
+		 * device configured like:
+		 * $ modprobe null-blk completion_nsec=100000000 irqmode=2
+		 * and then run with $ defer-taskrun.t /dev/nullb0
+		 */
+		filename = argv[1];
+	}
+
+	if (!t_probe_defer_taskrun())
+		return T_EXIT_SKIP;
+
+	ret = test_thread_shutdown();
+	if (ret) {
+		fprintf(stderr, "test_thread_shutdown failed\n");
+		return T_EXIT_FAIL;
+	}
+
+	ret = test_exec(filename);
+	if (ret) {
+		fprintf(stderr, "test_exec failed\n");
+		return T_EXIT_FAIL;
+	}
+
+	ret = test_eventfd();
+	if (ret) {
+		fprintf(stderr, "eventfd failed\n");
+		return T_EXIT_FAIL;
+	}
+
+	ret = test_flag();
+	if (ret) {
+		fprintf(stderr, "flag failed\n");
+		return T_EXIT_FAIL;
+	}
+
+	ret = test_ring_shutdown();
+	if (ret) {
+		fprintf(stderr, "test_ring_shutdown failed\n");
+		return T_EXIT_FAIL;
+	}
+
+	return T_EXIT_PASS;
+}
-- 
2.30.2