From 3da6e7e408b9c229e5e5cc1ddab7445c7561afc3 Mon Sep 17 00:00:00 2001 From: Benjamin Poirier Date: Mon, 15 Apr 2019 16:15:36 +0900 Subject: [PATCH] bpftool: Improve handling of ENOSPC on reuseport_array map dumps 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: key: 01 00 00 00 value: key: 02 00 00 00 value: Found 0 elements Signed-off-by: Benjamin Poirier Reviewed-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- tools/bpf/bpftool/map.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index df958af56b6c..44b192e87708 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -719,6 +719,9 @@ static int dump_map_elem(int fd, void *key, void *value, if (errno == ENOENT) msg = ""; + else if (lookup_errno == ENOSPC && + map_info->type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) + msg = ""; print_entry_error(map_info, key, msg ? : strerror(lookup_errno)); @@ -775,6 +778,10 @@ 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]); while (true) { err = bpf_map_get_next_key(fd, prev_key, key); if (err) { -- 2.30.2