On Fri, 12 Apr 2019 12:03:22 +0900, Benjamin Poirier wrote:
> avoids outputting a series of
> value:
> No space left on device
>
> The value itself is not wrong but bpf_fd_reuseport_array_lookup_elem() can
> only return it if the map was created with value_size = 8. There's nothing
> bpftool can do about it. Instead of repeating this error for every key in
> the map, print an explanatory warning and a specialized error.
>
> example before:
> key: 00 00 00 00
> value:
> No space left on device
> key: 01 00 00 00
> value:
> No space left on device
> key: 02 00 00 00
> value:
> No space left on device
> Found 0 elements
>
> example after:
> Warning: cannot read values from reuseport_sockarray map with value_size != 8
> key: 00 00 00 00 value: <cannot read>
> key: 01 00 00 00 value: <cannot read>
> key: 02 00 00 00 value: <cannot read>
> Found 0 elements
>
> Signed-off-by: Benjamin Poirier <bpoir...@suse.com>
> ---
> tools/bpf/bpftool/map.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
> index 71840faaeab5..e6d72f777767 100644
> --- a/tools/bpf/bpftool/map.c
> +++ b/tools/bpf/bpftool/map.c
> @@ -716,8 +716,12 @@ static int dump_map_elem(int fd, void *key, void *value,
> } else {
> const char *msg = NULL;
>
> - if (errno == ENOENT)
> + if (lookup_errno == ENOENT) {
> msg = "<no entry>";
> + } else if (lookup_errno == ENOSPC && map_info->type ==
> + BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
> + msg = "<cannot read>";
> + }
In addition to Quentin's nit please don't use the curly brackets for
single-line statements.
> print_entry_error(map_info, key,
> msg ? : strerror(lookup_errno), !!msg);
> @@ -774,6 +778,11 @@ static int do_dump(int argc, char **argv)
> }
> }
>
> + if (info.type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY &&
> + info.value_size != 8) {
> + p_info("Warning: cannot read values from %s map with value_size
> != 8",
> + map_type_name[info.type]);
> + }
Same here :)
> while (true) {
> err = bpf_map_get_next_key(fd, prev_key, key);
> if (err) {
