[PATCH v6 3/4] selftests: net: retry when bind returns EBUSY in xdp_helper

[Bui Quang Minh <minhquangbui99@gmail.com>]

When binding the XDP socket, we may get EBUSY because the deferred
destructor of XDP socket in previous test has not been executed yet. If
that is the case, just sleep and retry some times.

Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
---
 tools/testing/selftests/net/lib/xdp_helper.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/net/lib/xdp_helper.c b/tools/testing/selftests/net/lib/xdp_helper.c
index 6327863cafa6..eb025a9f35b1 100644
--- a/tools/testing/selftests/net/lib/xdp_helper.c
+++ b/tools/testing/selftests/net/lib/xdp_helper.c
@@ -38,6 +38,7 @@ int main(int argc, char **argv)
 	struct sockaddr_xdp sxdp = { 0 };
 	int num_desc = NUM_DESC;
 	void *umem_area;
+	int retry = 0;
 	int ifindex;
 	int sock_fd;
 	int queue;
@@ -102,11 +103,20 @@ int main(int argc, char **argv)
 		}
 	}
 
-	if (bind(sock_fd, (struct sockaddr *)&sxdp, sizeof(sxdp)) != 0) {
-		munmap(umem_area, UMEM_SZ);
-		perror("bind failed");
-		close(sock_fd);
-		return 1;
+	while (1) {
+		if (bind(sock_fd, (struct sockaddr *)&sxdp, sizeof(sxdp)) == 0)
+			break;
+
+		if (errno == EBUSY && retry < 3) {
+			retry++;
+			sleep(1);
+			continue;
+		} else {
+			perror("bind failed");
+			munmap(umem_area, UMEM_SZ);
+			close(sock_fd);
+			return 1;
+		}
 	}
 
 	ksft_ready();
-- 
2.43.0