test/sync-cancel: add test case for sync cancelation API

Signed-off-by: Jens Axboe <axboe@kernel.dk>

test/Makefile

@@ -159,6 +159,7 @@ test_srcs := \
 	stdout.c \
 	submit-link-fail.c \
 	submit-reuse.c \
+	sync-cancel.c \
 	symlink.c \
 	teardowns.c \
 	thread-exit.c \

test/sync-cancel.c

@@ -0,0 +1,235 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Description: test io_uring_register_sync_cancel()
+ *
+ */
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+
+#include "liburing.h"
+#include "helpers.h"
+
+static int no_sync_cancel;
+
+static int test_sync_cancel_timeout(struct io_uring *ring, int async)
+{
+	struct io_uring_sync_cancel_reg reg = { };
+	struct io_uring_sqe *sqe;
+	struct io_uring_cqe *cqe;
+	int ret, fds[2], to_prep;
+	char buf[32];
+
+	if (pipe(fds) < 0) {
+		perror("pipe");
+		return 1;
+	}
+
+	to_prep = 1;
+	sqe = io_uring_get_sqe(ring);
+	io_uring_prep_read(sqe, fds[0], buf, sizeof(buf), 0);
+	sqe->user_data = 0x89;
+	if (async)
+		sqe->flags |= IOSQE_ASYNC;
+
+	ret = io_uring_submit(ring);
+	if (ret != to_prep) {
+		fprintf(stderr, "submit=%d\n", ret);
+		return 1;
+	}
+
+	usleep(10000);
+
+	reg.addr = 0x89;
+	reg.timeout.tv_nsec = 1;
+	ret = io_uring_register_sync_cancel(ring, &reg);
+	if (async) {
+		/* we expect -ETIME here, but can race and get 0 */
+		if (ret != -ETIME && ret != 0) {
+			fprintf(stderr, "sync_cancel=%d\n", ret);
+			return 1;
+		}
+	} else {
+		if (ret < 0) {
+			fprintf(stderr, "sync_cancel=%d\n", ret);
+			return 1;
+		}
+	}
+
+	/*
+	 * we could _almost_ use peek_cqe() here, but there is still
+	 * a small gap where io-wq is done with the request and on
+	 * its way to posting a completion, but hasn't done it just
+	 * yet. the request is canceled and won't be doing any IO
+	 * to buffers etc, but the cqe may not have quite arrived yet.
+	 */
+	ret = io_uring_wait_cqe(ring, &cqe);
+	if (ret) {
+		fprintf(stderr, "peek=%d\n", ret);
+		return 1;
+	}
+	if (cqe->res >= 0) {
+		fprintf(stderr, "cqe->res=%d\n", cqe->res);
+		return 1;
+	}
+	io_uring_cqe_seen(ring, cqe);
+	return 0;
+}
+
+static int test_sync_cancel(struct io_uring *ring, int async, int nr_all,
+			    int use_fd)
+{
+	struct io_uring_sync_cancel_reg reg = { };
+	struct io_uring_sqe *sqe;
+	struct io_uring_cqe *cqe;
+	int ret, fds[2], to_prep, i;
+	char buf[32];
+
+	if (pipe(fds) < 0) {
+		perror("pipe");
+		return 1;
+	}
+
+	to_prep = 1;
+	if (nr_all)
+		to_prep = 4;
+	for (i = 0; i < to_prep; i++) {
+		sqe = io_uring_get_sqe(ring);
+		io_uring_prep_read(sqe, fds[0], buf, sizeof(buf), 0);
+		sqe->user_data = 0x89;
+		if (async)
+			sqe->flags |= IOSQE_ASYNC;
+	}
+
+	ret = io_uring_submit(ring);
+	if (ret != to_prep) {
+		fprintf(stderr, "submit=%d\n", ret);
+		return 1;
+	}
+
+	usleep(10000);
+
+	if (!use_fd)
+		reg.addr = 0x89;
+	else
+		reg.fd = fds[0];
+	reg.timeout.tv_sec = 200;
+	if (nr_all)
+		reg.flags |= IORING_ASYNC_CANCEL_ALL;
+	if (use_fd)
+		reg.flags |= IORING_ASYNC_CANCEL_FD;
+	ret = io_uring_register_sync_cancel(ring, &reg);
+	if (ret < 0) {
+		if (ret == -EINVAL && !no_sync_cancel) {
+			no_sync_cancel = 1;
+			return 0;
+		}
+		fprintf(stderr, "sync_cancel=%d\n", ret);
+		return 1;
+	}
+
+	for (i = 0; i < to_prep; i++) {
+		/*
+		 * we could _almost_ use peek_cqe() here, but there is still
+		 * a small gap where io-wq is done with the request and on
+		 * its way to posting a completion, but hasn't done it just
+		 * yet. the request is canceled and won't be doing any IO
+		 * to buffers etc, but the cqe may not have quite arrived yet.
+		 */
+		ret = io_uring_wait_cqe(ring, &cqe);
+		if (ret) {
+			fprintf(stderr, "peek=%d\n", ret);
+			return 1;
+		}
+		if (cqe->res >= 0) {
+			fprintf(stderr, "cqe->res=%d\n", cqe->res);
+			return 1;
+		}
+		io_uring_cqe_seen(ring, cqe);
+	}
+
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	struct io_uring ring;
+	int ret;
+
+	if (argc > 1)
+		return T_EXIT_SKIP;
+
+	ret = t_create_ring(7, &ring, 0);
+	if (ret == T_SETUP_SKIP)
+		return T_EXIT_SKIP;
+	else if (ret != T_SETUP_OK)
+		return ret;
+
+	ret = test_sync_cancel(&ring, 0, 0, 0);
+	if (ret) {
+		fprintf(stderr, "test_sync_cancel 0 0 0 failed\n");
+		return T_EXIT_FAIL;
+	}
+	if (no_sync_cancel)
+		return T_EXIT_SKIP;
+
+	ret = test_sync_cancel(&ring, 1, 0, 0);
+	if (ret) {
+		fprintf(stderr, "test_sync_cancel 1 0 0 failed\n");
+		return T_EXIT_FAIL;
+	}
+
+	ret = test_sync_cancel(&ring, 0, 1, 0);
+	if (ret) {
+		fprintf(stderr, "test_sync_cancel 0 1 0 failed\n");
+		return T_EXIT_FAIL;
+	}
+
+	ret = test_sync_cancel(&ring, 1, 1, 0);
+	if (ret) {
+		fprintf(stderr, "test_sync_cancel 1 1 0 failed\n");
+		return T_EXIT_FAIL;
+	}
+
+	ret = test_sync_cancel(&ring, 0, 0, 1);
+	if (ret) {
+		fprintf(stderr, "test_sync_cancel 0 0 1 failed\n");
+		return T_EXIT_FAIL;
+	}
+
+	ret = test_sync_cancel(&ring, 1, 0, 1);
+	if (ret) {
+		fprintf(stderr, "test_sync_cancel 1 0 1 failed\n");
+		return T_EXIT_FAIL;
+	}
+
+	ret = test_sync_cancel(&ring, 0, 1, 1);
+	if (ret) {
+		fprintf(stderr, "test_sync_cancel 0 1 1 failed\n");
+		return T_EXIT_FAIL;
+	}
+
+	ret = test_sync_cancel(&ring, 1, 1, 1);
+	if (ret) {
+		fprintf(stderr, "test_sync_cancel 1 1 1 failed\n");
+		return T_EXIT_FAIL;
+	}
+
+	ret = test_sync_cancel_timeout(&ring, 0);
+	if (ret) {
+		fprintf(stderr, "test_sync_cancel_timeout 0\n");
+		return T_EXIT_FAIL;
+	}
+
+	/* must be last, leaves request */
+	ret = test_sync_cancel_timeout(&ring, 1);
+	if (ret) {
+		fprintf(stderr, "test_sync_cancel_timeout 1\n");
+		return T_EXIT_FAIL;
+	}
+
+	return T_EXIT_PASS;
+}