On Tue, Aug 22, 2023 at 10:44 PM Daniel Xu <dxu@xxxxxxxxx> wrote:
>
> For bpf_object__pin_programs() there is bpf_object__unpin_programs().
> Likewise bpf_object__unpin_maps() for bpf_object__pin_maps().
>
> But no bpf_object__unpin() for bpf_object__pin(). Adding the former adds
> symmetry to the API.
>
> It's also convenient for cleanup in application code. It's an API I
> would've used if it was available for a repro I was writing earlier.
>
> Signed-off-by: Daniel Xu <dxu@xxxxxxxxx>
> ---
> tools/lib/bpf/libbpf.c | 15 +++++++++++++++
> tools/lib/bpf/libbpf.h | 1 +
> tools/lib/bpf/libbpf.map | 1 +
> 3 files changed, 17 insertions(+)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index 4c3967d94b6d..96ff1aa4bf6a 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -8376,6 +8376,21 @@ int bpf_object__pin(struct bpf_object *obj, const char *path)
> return 0;
> }
>
> +int bpf_object__unpin(struct bpf_object *obj, const char *path)
> +{
> + int err;
> +
> + err = bpf_object__unpin_programs(obj, path);
> + if (err)
> + return libbpf_err(err);
> +
> + err = bpf_object__unpin_maps(obj, path);
> + if (err)
> + return libbpf_err(err);
> +
> + return 0;
> +}
> +
pin APIs predate me, and I barely ever use them, but I wonder if
people feel fine with the fact that if any single unpin fails, all the
other programs/maps will not be unpinned? I also wonder if the best
effort unpinning of everything (while propagating first/last error) is
more practical? Looking at bpf_object__pin_programs, we try unpin
everything, even if some unpins fail.
Any thoughts or preferences?
> static void bpf_map__destroy(struct bpf_map *map)
> {
> if (map->inner_map) {
> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> index 2e3eb3614c40..0e52621cba43 100644
> --- a/tools/lib/bpf/libbpf.h
> +++ b/tools/lib/bpf/libbpf.h
> @@ -266,6 +266,7 @@ LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj,
> LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj,
> const char *path);
> LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path);
> +LIBBPF_API int bpf_object__unpin(struct bpf_object *object, const char *path);
>
> LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj);
> LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj);
> diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
> index 841a2f9c6fef..abf8fea3988e 100644
> --- a/tools/lib/bpf/libbpf.map
> +++ b/tools/lib/bpf/libbpf.map
> @@ -399,4 +399,5 @@ LIBBPF_1.3.0 {
> bpf_program__attach_netfilter;
> bpf_program__attach_tcx;
> bpf_program__attach_uprobe_multi;
> + bpf_object__unpin;
> } LIBBPF_1.2.0;
> --
> 2.41.0
>
