[PATCH liburing 0/2] tests for deferred multishot completions

[PATCH liburing 0/2] tests for deferred multishot completions

[Dylan Yudaken]

Hi,

This adds a couple of tests that expose some trickier corner cases for
multishot APIS, specifically in light of the latest series to batch &
defer multishot completion.


Dylan Yudaken (2):
  Add a test for errors in multishot recv
  add a test for multishot downgrading

 test/poll-mshot-overflow.c | 105 ++++++++++++++++++++++++++++++++++++-
 test/recv-multishot.c      |  85 ++++++++++++++++++++++++++++++
 2 files changed, 188 insertions(+), 2 deletions(-)


base-commit: b90a28636e5b5efe6dc1383acc90aec61814d9ba
-- 
2.30.2

[PATCH liburing 1/2] Add a test for errors in multishot recv

[Dylan Yudaken]

In a later kernel release there will be deferred completions of multishot
ops. Add a test to ensure ordering is preserved when there is an error
during the multishot operation.

Signed-off-by: Dylan Yudaken <dylany@meta.com>
---
 test/recv-multishot.c | 85 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 85 insertions(+)

diff --git a/test/recv-multishot.c b/test/recv-multishot.c
index ed26a5f78759..08a2e8629f5b 100644
--- a/test/recv-multishot.c
+++ b/test/recv-multishot.c
@@ -9,6 +9,7 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <pthread.h>
+#include <assert.h>
 
 #include "liburing.h"
 #include "helpers.h"
@@ -469,6 +470,84 @@ cleanup:
 	return ret;
 }
 
+static int test_enobuf(void)
+{
+	struct io_uring ring;
+	struct io_uring_sqe *sqe;
+	struct io_uring_cqe *cqes[16];
+	char buffs[256];
+	int ret, i, fds[2];
+
+	if (t_create_ring(8, &ring, 0) != T_SETUP_OK) {
+		fprintf(stderr, "ring create\n");
+		return -1;
+	}
+
+	ret = t_create_socket_pair(fds, false);
+	if (ret) {
+		fprintf(stderr, "t_create_socket_pair\n");
+		return ret;
+	}
+
+	sqe = io_uring_get_sqe(&ring);
+	assert(sqe);
+	/* deliberately only 2 provided buffers */
+	io_uring_prep_provide_buffers(sqe, &buffs[0], 1, 2, 0, 0);
+	io_uring_sqe_set_data64(sqe, 0);
+
+	sqe = io_uring_get_sqe(&ring);
+	assert(sqe);
+	io_uring_prep_recv_multishot(sqe, fds[0], NULL, 0, 0);
+	io_uring_sqe_set_data64(sqe, 1);
+	sqe->buf_group = 0;
+	sqe->flags |= IOSQE_BUFFER_SELECT;
+
+	ret = io_uring_submit(&ring);
+	if (ret != 2) {
+		fprintf(stderr, "bad submit %d\n", ret);
+		return -1;
+	}
+	for (i = 0; i < 3; i++) {
+		do {
+			ret = write(fds[1], "?", 1);
+		} while (ret == -1 && errno == EINTR);
+	}
+
+	ret = io_uring_wait_cqes(&ring, &cqes[0], 4, NULL, NULL);
+	if (ret) {
+		fprintf(stderr, "wait cqes\n");
+		return ret;
+	}
+
+	ret = io_uring_peek_batch_cqe(&ring, &cqes[0], 4);
+	if (ret != 4) {
+		fprintf(stderr, "peek batch cqes\n");
+		return -1;
+	}
+
+	/* provide buffers */
+	assert(cqes[0]->user_data == 0);
+	assert(cqes[0]->res == 0);
+
+	/* valid recv */
+	assert(cqes[1]->user_data == 1);
+	assert(cqes[2]->user_data == 1);
+	assert(cqes[1]->res == 1);
+	assert(cqes[2]->res == 1);
+	assert(cqes[1]->flags & (IORING_CQE_F_BUFFER | IORING_CQE_F_MORE));
+	assert(cqes[2]->flags & (IORING_CQE_F_BUFFER | IORING_CQE_F_MORE));
+
+	/* missing buffer */
+	assert(cqes[3]->user_data == 1);
+	assert(cqes[3]->res == -ENOBUFS);
+	assert(!(cqes[3]->flags & (IORING_CQE_F_BUFFER | IORING_CQE_F_MORE)));
+
+	close(fds[0]);
+	close(fds[1]);
+	io_uring_queue_exit(&ring);
+	return 0;
+}
+
 int main(int argc, char *argv[])
 {
 	int ret;
@@ -509,5 +588,11 @@ int main(int argc, char *argv[])
 		}
 	}
 
+	ret = test_enobuf();
+	if (ret) {
+		fprintf(stderr, "test_enobuf() failed: %d\n", ret);
+		return T_EXIT_FAIL;
+	}
+
 	return T_EXIT_PASS;
 }

base-commit: b90a28636e5b5efe6dc1383acc90aec61814d9ba
-- 
2.30.2

[PATCH liburing 2/2] add a test for multishot downgrading

[Dylan Yudaken]

If the poll overflows we expect multishot poll to eventually downgrade to
single shot. Also the ordering of CQE's must be consistent, so check that.

Signed-off-by: Dylan Yudaken <dylany@meta.com>
---
 test/poll-mshot-overflow.c | 105 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 104 insertions(+), 1 deletion(-)

diff --git a/test/poll-mshot-overflow.c b/test/poll-mshot-overflow.c
index 431a337f19ae..0dc8ee5eb6f8 100644
--- a/test/poll-mshot-overflow.c
+++ b/test/poll-mshot-overflow.c
@@ -137,20 +137,123 @@ static int test(bool defer_taskrun)
 	return ret;
 }
 
+static int test_downgrade(bool support_defer)
+{
+	struct io_uring_cqe cqes[128];
+	struct io_uring_cqe *cqe;
+	struct io_uring_sqe *sqe;
+	struct io_uring ring;
+	int fds[2];
+	int ret, i, cqe_count, tmp = 0, more_cqe_count;
+
+	if (pipe(fds) != 0) {
+		perror("pipe");
+		return -1;
+	}
+
+	struct io_uring_params params = {
+		.flags = IORING_SETUP_CQSIZE,
+		.cq_entries = 2
+	};
+
+	ret = io_uring_queue_init_params(2, &ring, &params);
+	if (ret) {
+		fprintf(stderr, "queue init: %d\n", ret);
+		return -1;
+	}
+
+	sqe = io_uring_get_sqe(&ring);
+	if (!sqe) {
+		fprintf(stderr, "get sqe failed\n");
+		return -1;
+	}
+	io_uring_prep_poll_multishot(sqe, fds[0], POLLIN);
+	io_uring_sqe_set_data64(sqe, 1);
+	io_uring_submit(&ring);
+
+	for (i = 0; i < 8; i++) {
+		ret = write(fds[1], &tmp, sizeof(tmp));
+		if (ret != sizeof(tmp)) {
+			perror("write");
+			return -1;
+		}
+		ret = read(fds[0], &tmp, sizeof(tmp));
+		if (ret != sizeof(tmp)) {
+			perror("read");
+			return -1;
+		}
+	}
+
+	cqe_count = 0;
+	while (!io_uring_peek_cqe(&ring, &cqe)) {
+		cqes[cqe_count++] = *cqe;
+		io_uring_cqe_seen(&ring, cqe);
+	}
+
+	/* Some kernels might allow overflows to poll,
+	 * but if they didn't it should stop the MORE flag
+	 */
+	if (cqe_count < 3) {
+		fprintf(stderr, "too few cqes: %d\n", cqe_count);
+		return -1;
+	} else if (cqe_count == 8) {
+		more_cqe_count = cqe_count;
+		/* downgrade only available since support_defer */
+		if (support_defer) {
+			fprintf(stderr, "did not downgrade on overflow\n");
+			return -1;
+		}
+	} else {
+		more_cqe_count = cqe_count - 1;
+		cqe = &cqes[cqe_count - 1];
+		if (cqe->flags & IORING_CQE_F_MORE) {
+			fprintf(stderr, "incorrect MORE flag %x\n", cqe->flags);
+			return -1;
+		}
+	}
+
+	for (i = 0; i < more_cqe_count; i++) {
+		cqe = &cqes[i];
+		if (!(cqe->flags & IORING_CQE_F_MORE)) {
+			fprintf(stderr, "missing MORE flag\n");
+			return -1;
+		}
+		if (cqe->res < 0) {
+			fprintf(stderr, "bad res: %d\n", cqe->res);
+			return -1;
+		}
+	}
+
+	close(fds[0]);
+	close(fds[1]);
+	io_uring_queue_exit(&ring);
+	return 0;
+}
+
 int main(int argc, char *argv[])
 {
 	int ret;
+	bool support_defer;
 
 	if (argc > 1)
 		return T_EXIT_SKIP;
 
+	support_defer = t_probe_defer_taskrun();
+	ret = test_downgrade(support_defer);
+	if (ret) {
+		fprintf(stderr, "%s: test_downgrade(%d) failed\n", argv[0], support_defer);
+		return T_EXIT_FAIL;
+	}
+
 	ret = test(false);
+	if (ret == T_EXIT_SKIP)
+		return ret;
 	if (ret != T_EXIT_PASS) {
 		fprintf(stderr, "%s: test(false) failed\n", argv[0]);
 		return ret;
 	}
 
-	if (t_probe_defer_taskrun()) {
+	if (support_defer) {
 		ret = test(true);
 		if (ret != T_EXIT_PASS) {
 			fprintf(stderr, "%s: test(true) failed\n", argv[0]);
-- 
2.30.2

Re: [PATCH liburing 0/2] tests for deferred multishot completions

[Jens Axboe]

On Thu, 24 Nov 2022 02:30:40 -0800, Dylan Yudaken wrote:
> This adds a couple of tests that expose some trickier corner cases for
> multishot APIS, specifically in light of the latest series to batch &
> defer multishot completion.
> 
> 
> Dylan Yudaken (2):
>   Add a test for errors in multishot recv
>   add a test for multishot downgrading
> 
> [...]

Applied, thanks!

[1/2] Add a test for errors in multishot recv
      (no commit info)
[2/2] add a test for multishot downgrading
      (no commit info)

Best regards,
-- 
Jens Axboe