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@brb
Created Jul 22, 2021
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libbpf map pin race
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;
}
}
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