libbpf map pin race

libbpf.diff

diff --git a/src/libbpf.c b/src/libbpf.c
index a97490c..4587950 100644
--- a/src/libbpf.c
+++ b/src/libbpf.c
@@ -4686,10 +4686,13 @@ bpf_object__create_maps(struct bpf_object *obj)
 	char *cp, errmsg[STRERR_BUFSIZE];
 	unsigned int i, j;
 	int err;
+	bool retried;
 
 	for (i = 0; i < obj->nr_maps; i++) {
 		map = &obj->maps[i];
 
+		retried = false;
+retry:
 		if (map->pin_path) {
 			err = bpf_object__reuse_map(map);
 			if (err) {
@@ -4697,6 +4700,12 @@ bpf_object__create_maps(struct bpf_object *obj)
 					map->name);
 				goto err_out;
 			}
+			if (retried && map->fd < 0) {
+				pr_warn("map '%s': cannot find pinned map\n",
+					map->name);
+				err = -ENOENT;
+				goto err_out;
+			}
 		}
 
 		if (map->fd >= 0) {
@@ -4730,9 +4739,13 @@ bpf_object__create_maps(struct bpf_object *obj)
 		if (map->pin_path && !map->pinned) {
 			err = bpf_map__pin(map, NULL);
 			if (err) {
+				zclose(map->fd);
+				if (!retried && err == -EEXIST) {
+					retried = true;
+					goto retry;
+				}
 				pr_warn("map '%s': failed to auto-pin at '%s': %d\n",
 					map->name, map->pin_path, err);
-				zclose(map->fd);
 				goto err_out;
 			}
 		}