From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AF703C10F13 for ; Thu, 11 Apr 2019 08:27:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 89BC52083E for ; Thu, 11 Apr 2019 08:27:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726723AbfDKI1L (ORCPT ); Thu, 11 Apr 2019 04:27:11 -0400 Received: from mx2.suse.de ([195.135.220.15]:58992 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725793AbfDKI1K (ORCPT ); Thu, 11 Apr 2019 04:27:10 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 887CEAC69; Thu, 11 Apr 2019 08:27:09 +0000 (UTC) From: Benjamin Poirier To: Daniel Borkmann Cc: netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH bpf-next] bpftool: Exit early when it's not possible to dump a REUSEPORT_SOCKARRAY map Date: Thu, 11 Apr 2019 17:27:00 +0900 Message-Id: <20190411082700.26888-1-bpoirier@suse.com> X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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 the error once, print an explanatory message and exit. Signed-off-by: Benjamin Poirier --- Note that this will lead to a merge conflict if the patch "bpftool: Fix errno variable usage" is merged in the bpf branch: <<<<<<< HEAD if (lookup_errno == ENOENT) ======= if (errno == ENOENT) { >>>>>>> bpf-next The resolution should be trivial: if (lookup_errno == ENOENT) { tools/bpf/bpftool/map.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index e96903078991..bb648e42923c 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -684,7 +684,6 @@ static int dump_map_elem(int fd, void *key, void *value, struct bpf_map_info *map_info, struct btf *btf, json_writer_t *btf_wtr) { - int num_elems = 0; int lookup_errno; if (!bpf_map_lookup_elem(fd, key, value)) { @@ -702,9 +701,8 @@ static int dump_map_elem(int fd, void *key, void *value, } else { print_entry_plain(map_info, key, value); } - num_elems++; } - return num_elems; + return 1; } /* lookup error handling */ @@ -722,11 +720,13 @@ static int dump_map_elem(int fd, void *key, void *value, jsonw_string_field(json_wtr, "error", strerror(lookup_errno)); jsonw_end_object(json_wtr); } else { - if (errno == ENOENT) + if (errno == ENOENT) { print_entry_plain(map_info, key, NULL); - else + } else { print_entry_error(map_info, key, strerror(lookup_errno)); + return -lookup_errno; + } } return 0; @@ -787,7 +787,16 @@ static int do_dump(int argc, char **argv) err = 0; break; } - num_elems += dump_map_elem(fd, key, value, &info, btf, btf_wtr); + err = dump_map_elem(fd, key, value, &info, btf, btf_wtr); + /* bpf_fd_reuseport_array_lookup_elem() can only return a + * value if the map's value_size == 8 + */ + if (info.type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY && + info.value_size != 8 && err == -ENOSPC) { + p_err("cannot dump REUSEPORT_SOCKARRAY map with value_size != 8"); + goto exit_free; + } + num_elems += err; prev_key = key; } -- 2.21.0