[PATCH liburing] tests: Add test for bid limits of provided_buffer commands

[Gabriel Krisman Bertazi <krisman@suse.de>]

A couple of tests for bid limits when allocating/freeing
buffers with provide_buffers command.

Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
---
 test/Makefile          |   1 +
 test/provide-buffers.c | 132 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 133 insertions(+)
 create mode 100644 test/provide-buffers.c

diff --git a/test/Makefile b/test/Makefile
index f16cedc..60ca45f 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -138,6 +138,7 @@ test_srcs := \
 	poll-v-poll.c \
 	pollfree.c \
 	probe.c \
+	provide-buffers.c \
 	read-before-exit.c \
 	read-write.c \
 	recv-msgall.c \
diff --git a/test/provide-buffers.c b/test/provide-buffers.c
new file mode 100644
index 0000000..62fd8d8
--- /dev/null
+++ b/test/provide-buffers.c
@@ -0,0 +1,132 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Description: test BID checks for provide buffers command.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include <sys/mman.h>
+
+#include "liburing.h"
+#include "helpers.h"
+
+/* BID id address space is 16 bits. */
+#define MAX_BID_NR (1<<16)
+
+int test_bid_space_limits()
+{
+	struct io_uring ring;
+	struct io_uring_sqe *sqe;
+	struct io_uring_cqe *cqe;
+	void * buf;
+	int buf_len;
+	int ret;
+
+	ret = io_uring_queue_init(1, &ring, 0);
+	if (ret < 0) {
+		fprintf(stderr, "queue_init: %s\n", strerror(-ret));
+		return 1;
+	}
+
+	/*
+	 * Individual buffer size (buf_len) is irrelevant for this
+	 * test. As long as the full size can be mapped and io_uring
+	 * likes it. sizeof(int) is always safe.
+	 */
+	buf_len = sizeof(int);
+	buf = mmap(NULL, MAX_BID_NR*buf_len, PROT_READ|PROT_WRITE,
+		   MAP_PRIVATE|MAP_ANON, -1, 0);
+	if (buf == MAP_FAILED) {
+		fprintf(stderr, "mmap failed\n");
+		return 1;
+	}
+
+	/* allocate/free the last tag possible for a given bid. */
+	sqe = io_uring_get_sqe(&ring);
+	io_uring_prep_provide_buffers(sqe, buf, buf_len, 1, 0, USHRT_MAX);
+	io_uring_submit(&ring);
+	io_uring_wait_cqe(&ring, &cqe);
+	if (ret) {
+		fprintf(stderr, "wait_cqe %d\n", ret);
+		return 1;
+	} else if (cqe->res != 0) {
+		fprintf(stderr, "Failed to register buffer with tag USHRT_MAX. (res = %d)\n",
+			cqe->res);
+		return 1;
+	}
+	io_uring_cqe_seen(&ring, cqe);
+
+	sqe = io_uring_get_sqe(&ring);
+	io_uring_prep_remove_buffers(sqe, 1, 0);
+	io_uring_submit(&ring);
+	io_uring_wait_cqe(&ring, &cqe);
+	if (ret) {
+		fprintf(stderr, "wait_cqe %d\n", ret);
+		return 1;
+	} else if (cqe->res != 1) {
+		fprintf(stderr, "Failed to remove buffer with tag USHRT_MAX. (res = %d)\n",
+			cqe->res);
+		return 1;
+	}
+	io_uring_cqe_seen(&ring, cqe);
+
+	/* Wrapping the bid counter could be valid but is confusing, thus it is disabled. */
+	sqe = io_uring_get_sqe(&ring);
+	io_uring_prep_provide_buffers(sqe, buf, buf_len, 2, 0, USHRT_MAX);
+	io_uring_submit(&ring);
+	io_uring_wait_cqe(&ring, &cqe);
+	if (ret) {
+		fprintf(stderr, "wait_cqe %d\n", ret);
+		return 1;
+	} else if (cqe->res == 0) {
+		fprintf(stderr, "Shouldn't have succeded to register the BID counter.\n");
+		return 1;
+	}
+	io_uring_cqe_seen(&ring, cqe);
+
+	/* Allocate and free the full address space */
+	sqe = io_uring_get_sqe(&ring);
+	io_uring_prep_provide_buffers(sqe, buf, buf_len, MAX_BID_NR, 0, 0);
+	io_uring_submit(&ring);
+	io_uring_wait_cqe(&ring, &cqe);
+	if (ret) {
+		fprintf(stderr, "wait_cqe %d\n", ret);
+		return 1;
+	} else if (cqe->res != 0) {
+		fprintf(stderr, "Failed to register 65536 buffers. (res = %d)\n",
+			cqe->res);
+		return 1;
+	}
+	io_uring_cqe_seen(&ring, cqe);
+
+	sqe = io_uring_get_sqe(&ring);
+	io_uring_prep_remove_buffers(sqe, MAX_BID_NR, 0);
+	io_uring_submit(&ring);
+	io_uring_wait_cqe(&ring, &cqe);
+	if (ret) {
+		fprintf(stderr, "wait_cqe %d\n", ret);
+		return 1;
+	} else if (cqe->res != MAX_BID_NR) {
+		fprintf(stderr, "Failed to remove 65536 buffers.\n");
+		return 1;
+	}
+	io_uring_cqe_seen(&ring, cqe);
+
+	io_uring_queue_exit(&ring);
+
+	return 0;
+}
+
+int main (int argc, char *argv[])
+{
+	int ret;
+
+	if (argc > 1)
+		return T_EXIT_SKIP;
+
+	ret = test_bid_space_limits();
+	if (ret)
+		return T_EXIT_FAIL;
+	return T_EXIT_PASS;
+}
-- 
2.42.0