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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 30C4FC433EF for ; Thu, 7 Apr 2022 22:43:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232306AbiDGWpU (ORCPT ); Thu, 7 Apr 2022 18:45:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37344 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232285AbiDGWpO (ORCPT ); Thu, 7 Apr 2022 18:45:14 -0400 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6AB42154713 for ; Thu, 7 Apr 2022 15:43:12 -0700 (PDT) Received: by mail-pf1-x449.google.com with SMTP id h131-20020a628389000000b005056723a9dcso1813578pfe.8 for ; Thu, 07 Apr 2022 15:43:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=pAk5rXzYOgjs6QN7PF4DKfEiueSRXqJopL6r+G+SYMg=; b=qv/ZfWS96JL8ToxxS9HkzUsNxcgjDjomFpfz2944+t+BaDBFk//TDRRG0EQou1qHv2 eqtDQoRcsXpquUS0GLLciQ+s6RJpZuc5N56AEikJDuC/RYBBajToGFWwv8SSCf70AJn5 nAvqvnMqE3DpzvAAnlizcVl8NObJlzGhEZrLv1CqOzM7NbEyFhaP9l17bP/X/kcgXvqH Z383gcxcH0YzFx6TkICE9yiq1GpgaghTRTqqOm1KrLlQVkWbnwK1LdgyPxl33cFL/TQS APv0PQrKflod2nwRa68HyFfut0wbUsxWxrxhZDN+gvGGIijQIlAlL739L4M7oVvMtwlR WQkQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=pAk5rXzYOgjs6QN7PF4DKfEiueSRXqJopL6r+G+SYMg=; b=wfUROhRzA9bgvqqaLobpRqhM0+IS/h2XVyJzEx2tWRS8nX/iO1avnY8HDDoScsMQFe BJak93Q3cDdON7v9q1ERLUnhCZ2j/2Z2lgP5BP6cRELbM1wqx/HZHdXy95aHGmjRzo8c O6tQpm4E+VZc8+IpebMysVUKS4+nxMtM4pZ23yj48o1ht4YmSocaASoo02eFVlePeMfV a0KAZAdcpsv9QIqn7jHrGQ1pM6UN1GwSs4LZ2M3V6JNmCeZReOd0rL63jvh1xs2l6PCd z8QveR1kreicD2lc2+iMuG7/xMXY0yTLRPFe9Onmfjq5LH7hvkHKtCyNANFGjOSbwkUO ftuA== X-Gm-Message-State: AOAM533Wo4NsBS+mirp3Eyt7B6Z7LY/+H7N8HP4yBidJFi15XNFGc+9n ntpJ8iqyV4iZJQa+AeUuiBWpdhdj6sG/GIwh X-Google-Smtp-Source: ABdhPJz/m6t1/bLDKPjThB/2Yt1mSc3IiH/+dngiTDVwURy7M/hstiNpOlv5+A8nC+3p1I4e1xSZSGYn6L82YpXb X-Received: from yosry.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:2327]) (user=yosryahmed job=sendgmr) by 2002:a17:902:b694:b0:153:1d9a:11a5 with SMTP id c20-20020a170902b69400b001531d9a11a5mr16223355pls.151.1649371391903; Thu, 07 Apr 2022 15:43:11 -0700 (PDT) Date: Thu, 7 Apr 2022 22:42:42 +0000 In-Reply-To: <20220407224244.1374102-1-yosryahmed@google.com> Message-Id: <20220407224244.1374102-3-yosryahmed@google.com> Mime-Version: 1.0 References: <20220407224244.1374102-1-yosryahmed@google.com> X-Mailer: git-send-email 2.35.1.1178.g4f1659d476-goog Subject: [PATCH v2 2/4] selftests: cgroup: return the errno of write() in cg_write() on failure From: Yosry Ahmed To: Johannes Weiner , Michal Hocko , Shakeel Butt , Andrew Morton , Roman Gushchin Cc: David Rientjes , Tejun Heo , Zefan Li , Jonathan Corbet , Shuah Khan , Yu Zhao , Dave Hansen , Wei Xu , Greg Thelen , Chen Wandun , Vaibhav Jain , Huang@google.com, Ying , "=?UTF-8?q?Michal=20Koutn=C3=BD?=" , Tim Chen , cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Yosry Ahmed Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently, cg_write() returns 0 on success and -1 on failure. Modify it to return the errno of write() syscall on failure. Signed-off-by: Yosry Ahmed --- tools/testing/selftests/cgroup/cgroup_util.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/cgroup_util.c index dbaa7aabbb4a..ef76db6026aa 100644 --- a/tools/testing/selftests/cgroup/cgroup_util.c +++ b/tools/testing/selftests/cgroup/cgroup_util.c @@ -48,6 +48,8 @@ static ssize_t write_text(const char *path, char *buf, ssize_t len) len = write(fd, buf, len); if (len < 0) { + /* preserve the errno of write() */ + len = errno; close(fd); return len; } @@ -177,17 +179,16 @@ long cg_read_lc(const char *cgroup, const char *control) return cnt; } +/* Returns 0 on success, or the errno of write() on failure. */ int cg_write(const char *cgroup, const char *control, char *buf) { char path[PATH_MAX]; - ssize_t len = strlen(buf); + ssize_t len = strlen(buf), ret; snprintf(path, sizeof(path), "%s/%s", cgroup, control); - if (write_text(path, buf, len) == len) - return 0; - - return -1; + ret = write_text(path, buf, len); + return ret == len ? 0 : ret; } int cg_find_unified_root(char *root, size_t len) -- 2.35.1.1178.g4f1659d476-goog From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yosry Ahmed Subject: [PATCH v2 2/4] selftests: cgroup: return the errno of write() in cg_write() on failure Date: Thu, 7 Apr 2022 22:42:42 +0000 Message-ID: <20220407224244.1374102-3-yosryahmed@google.com> References: <20220407224244.1374102-1-yosryahmed@google.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=pAk5rXzYOgjs6QN7PF4DKfEiueSRXqJopL6r+G+SYMg=; b=qv/ZfWS96JL8ToxxS9HkzUsNxcgjDjomFpfz2944+t+BaDBFk//TDRRG0EQou1qHv2 eqtDQoRcsXpquUS0GLLciQ+s6RJpZuc5N56AEikJDuC/RYBBajToGFWwv8SSCf70AJn5 nAvqvnMqE3DpzvAAnlizcVl8NObJlzGhEZrLv1CqOzM7NbEyFhaP9l17bP/X/kcgXvqH Z383gcxcH0YzFx6TkICE9yiq1GpgaghTRTqqOm1KrLlQVkWbnwK1LdgyPxl33cFL/TQS APv0PQrKflod2nwRa68HyFfut0wbUsxWxrxhZDN+gvGGIijQIlAlL739L4M7oVvMtwlR WQkQ== In-Reply-To: <20220407224244.1374102-1-yosryahmed-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Johannes Weiner , Michal Hocko , Shakeel Butt , Andrew Morton , Roman Gushchin Cc: David Rientjes , Tejun Heo , Zefan Li , Jonathan Corbet , Shuah Khan , Yu Zhao , Dave Hansen , Wei Xu , Greg Thelen , Chen Wandun , Vaibhav Jain , Huang-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, Ying , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Tim Chen , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-kselftest-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Yosry Ahmed Currently, cg_write() returns 0 on success and -1 on failure. Modify it to return the errno of write() syscall on failure. Signed-off-by: Yosry Ahmed --- tools/testing/selftests/cgroup/cgroup_util.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/cgroup_util.c index dbaa7aabbb4a..ef76db6026aa 100644 --- a/tools/testing/selftests/cgroup/cgroup_util.c +++ b/tools/testing/selftests/cgroup/cgroup_util.c @@ -48,6 +48,8 @@ static ssize_t write_text(const char *path, char *buf, ssize_t len) len = write(fd, buf, len); if (len < 0) { + /* preserve the errno of write() */ + len = errno; close(fd); return len; } @@ -177,17 +179,16 @@ long cg_read_lc(const char *cgroup, const char *control) return cnt; } +/* Returns 0 on success, or the errno of write() on failure. */ int cg_write(const char *cgroup, const char *control, char *buf) { char path[PATH_MAX]; - ssize_t len = strlen(buf); + ssize_t len = strlen(buf), ret; snprintf(path, sizeof(path), "%s/%s", cgroup, control); - if (write_text(path, buf, len) == len) - return 0; - - return -1; + ret = write_text(path, buf, len); + return ret == len ? 0 : ret; } int cg_find_unified_root(char *root, size_t len) -- 2.35.1.1178.g4f1659d476-goog