On Tue, Jan 14, 2020 at 05:34:33PM -0800, Andrii Nakryiko wrote:
> On Tue, Jan 14, 2020 at 2:45 PM Martin KaFai Lau <kafai@xxxxxx> wrote:
> >
> > The btf availability check is only done for plain text output.
> > It causes the whole BTF output went missing when json_output
> > is used.
> >
> > This patch simplifies the logic a little by avoiding passing "int btf" to
> > map_dump().
> >
> > For plain text output, the btf_wtr is only created when the map has
> > BTF (i.e. info->btf_id != 0). The nullness of "json_writer_t *wtr"
> > in map_dump() alone can decide if dumping BTF output is needed.
> > As long as wtr is not NULL, map_dump() will print out the BTF-described
> > data whenever a map has BTF available (i.e. info->btf_id != 0)
> > regardless of json or plain-text output.
> >
> > In do_dump(), the "int btf" is also renamed to "int do_plain_btf".
> >
> > Fixes: 99f9863a0c45 ("bpftool: Match maps by name")
> > Cc: Paul Chaignon <paul.chaignon@xxxxxxxxxx>
> > Signed-off-by: Martin KaFai Lau <kafai@xxxxxx>
> > ---
>
> just one nit below
>
> Acked-by: Andrii Nakryiko <andriin@xxxxxx>
>
> > tools/bpf/bpftool/map.c | 42 ++++++++++++++++++++---------------------
> > 1 file changed, 20 insertions(+), 22 deletions(-)
> >
> > diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
> > index e00e9e19d6b7..45c1eda6512c 100644
> > --- a/tools/bpf/bpftool/map.c
> > +++ b/tools/bpf/bpftool/map.c
> > @@ -933,7 +933,7 @@ static int maps_have_btf(int *fds, int nb_fds)
> >
> > static int
> > map_dump(int fd, struct bpf_map_info *info, json_writer_t *wtr,
> > - bool enable_btf, bool show_header)
> > + bool show_header)
> > {
> > void *key, *value, *prev_key;
> > unsigned int num_elems = 0;
> > @@ -950,18 +950,16 @@ map_dump(int fd, struct bpf_map_info *info, json_writer_t *wtr,
> >
> > prev_key = NULL;
> >
> > - if (enable_btf) {
> > - err = btf__get_from_id(info->btf_id, &btf);
> > - if (err || !btf) {
> > - /* enable_btf is true only if we've already checked
> > - * that all maps have BTF information.
> > - */
> > - p_err("failed to get btf");
> > - goto exit_free;
> > + if (wtr) {
> > + if (info->btf_id) {
>
> combine into if (wtr && info->btf_id) and reduce nestedness?
There is other logic under the same "if (wtr)".
Thus, it is better to leave it as is.
and this indentation will be gone in patch 5.
>
>
> > + err = btf__get_from_id(info->btf_id, &btf);
> > + if (err || !btf) {
> > + err = err ? : -ESRCH;
> > + p_err("failed to get btf");
> > + goto exit_free;
> > + }
>
> [...]
