[PATCH bpf-next 1/3] libbpf: Store map pin path in struct bpf_map

[Toke Høiland-Jørgensen <toke@xxxxxxxxxx>]

From: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>

When pinning a map, store the pin path in struct bpf_map so it can be
re-used later for un-pinning. This simplifies the later addition of per-map
pin paths.

Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
---
 tools/lib/bpf/libbpf.c |   19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index cccfd9355134..b4fdd8ee3bbd 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -226,6 +226,7 @@ struct bpf_map {
 	void *priv;
 	bpf_map_clear_priv_t clear_priv;
 	enum libbpf_map_type libbpf_type;
+	char *pin_path;
 };
 
 struct bpf_secdata {
@@ -1929,6 +1930,7 @@ int bpf_map__reuse_fd(struct bpf_map *map, int fd)
 	if (err)
 		goto err_close_new_fd;
 	free(map->name);
+	zfree(&map->pin_path);
 
 	map->fd = new_fd;
 	map->name = new_name;
@@ -4022,6 +4024,7 @@ int bpf_map__pin(struct bpf_map *map, const char *path)
 		return -errno;
 	}
 
+	map->pin_path = strdup(path);
 	pr_debug("pinned map '%s'\n", path);
 
 	return 0;
@@ -4031,6 +4034,9 @@ int bpf_map__unpin(struct bpf_map *map, const char *path)
 {
 	int err;
 
+	if (!path)
+		path = map->pin_path;
+
 	err = check_path(path);
 	if (err)
 		return err;
@@ -4044,6 +4050,7 @@ int bpf_map__unpin(struct bpf_map *map, const char *path)
 	if (err != 0)
 		return -errno;
 	pr_debug("unpinned map '%s'\n", path);
+	zfree(&map->pin_path);
 
 	return 0;
 }
@@ -4088,17 +4095,10 @@ int bpf_object__pin_maps(struct bpf_object *obj, const char *path)
 
 err_unpin_maps:
 	while ((map = bpf_map__prev(map, obj))) {
-		char buf[PATH_MAX];
-		int len;
-
-		len = snprintf(buf, PATH_MAX, "%s/%s", path,
-			       bpf_map__name(map));
-		if (len < 0)
-			continue;
-		else if (len >= PATH_MAX)
+		if (!map->pin_path)
 			continue;
 
-		bpf_map__unpin(map, buf);
+		bpf_map__unpin(map, NULL);
 	}
 
 	return err;
@@ -4248,6 +4248,7 @@ void bpf_object__close(struct bpf_object *obj)
 
 	for (i = 0; i < obj->nr_maps; i++) {
 		zfree(&obj->maps[i].name);
+		zfree(&obj->maps[i].pin_path);
 		if (obj->maps[i].clear_priv)
 			obj->maps[i].clear_priv(&obj->maps[i],
 						obj->maps[i].priv);