Re: [PATCH bpf-next v5 2/5] libbpf: Store map pin path and status in struct bpf_map

Andrii Nakryiko [off-list ref] writes:

On Fri, Nov 1, 2019 at 2:53 AM Toke Høiland-Jørgensen [off-list ref] wrote:

quoted

From: Toke Høiland-Jørgensen <redacted>

Support storing and setting a pin path in struct bpf_map, which can be used
for automatic pinning. Also store the pin status so we can avoid attempts
to re-pin a map that has already been pinned (or reused from a previous
pinning).

The behaviour of bpf_object__{un,}pin_maps() is changed so that if it is
called with a NULL path argument (which was previously illegal), it will
(un)pin only those maps that have a pin_path set.

Acked-by: Andrii Nakryiko <redacted>
Signed-off-by: Toke Høiland-Jørgensen <redacted>
---
 tools/lib/bpf/libbpf.c   |  164 +++++++++++++++++++++++++++++++++++-----------
 tools/lib/bpf/libbpf.h   |    8 ++
 tools/lib/bpf/libbpf.map |    3 +
 3 files changed, 134 insertions(+), 41 deletions(-)

[...]

quoted

 LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path);
 LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj,
                                      const char *path);

@@ -385,6 +390,9 @@ LIBBPF_API int bpf_map__resize(struct bpf_map *map, __u32 max_entries);
 LIBBPF_API bool bpf_map__is_offload_neutral(const struct bpf_map *map);
 LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map);
 LIBBPF_API void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
+LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path);
+LIBBPF_API const char *bpf_map__get_pin_path(struct bpf_map *map);
+LIBBPF_API bool bpf_map__is_pinned(struct bpf_map *map);

Didn't notice this before and wasn't going to force another version
just for this, but given you'll be fixing last patch anyways...
bpf_map__is_pinned and bpf_map__get_pin_path are read-only "getters",
so it would be appropriate for them to accept "const struct bpf_map *"
instead.

Can do :)