From patchwork Thu Apr 21 23:44:24 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yosry Ahmed X-Patchwork-Id: 565140 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 6551AC433FE for ; Thu, 21 Apr 2022 23:44:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1442706AbiDUXrl (ORCPT ); Thu, 21 Apr 2022 19:47:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45864 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1442734AbiDUXrh (ORCPT ); Thu, 21 Apr 2022 19:47:37 -0400 Received: from mail-pg1-x549.google.com (mail-pg1-x549.google.com [IPv6:2607:f8b0:4864:20::549]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3372B3C73E for ; Thu, 21 Apr 2022 16:44:46 -0700 (PDT) Received: by mail-pg1-x549.google.com with SMTP id 83-20020a630556000000b003aa61747c38so3598413pgf.8 for ; Thu, 21 Apr 2022 16:44:46 -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=o1jm2ZxrobVfc+EDXZbKA8synQY3urRJFo8ts6M9Cos=; b=XNmIj+vh/zg85pOZ7hddsPc4rZoBWgPyUKppuibPQ8HpozXmQF4+KbncIhebNDLW+A OaXTK2I3Y4FSfd6Gk2xjKvidVm8LAaC0kUVGEo9TUpGjqdno7WSghhitFdSbSpl49CsV tN/y2CDjCmmhUJ5bWM3jDcayzcK/VRUFAN/fq1h0P/eGY5Hy+hXEJyzvjDolAnIyIh8w 7uodhfP1m0/4SgHnVku88XUlvSW+55VzyEWrQhAUPNeD6F+CC6uOkZE3RyW5PPK9/T9U kH6ybVBPt6zTUU/GcTYAtffLbYejeX7CoHq85fV8abFrT+jgJziiU3RQIdVNZSFNsFws rRVA== 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=o1jm2ZxrobVfc+EDXZbKA8synQY3urRJFo8ts6M9Cos=; b=4grLz5FDdi0/3E6PQtEmBFV/zH4KUiSLqaNINQH/qoP5jCwFb0xgSdp+WY+JXIXgdt b45QaDmKO+CdXjArF5KqnpdaxVSh5vI8VLa9ywdEsIQ0JGmxHTH1O3I+5CHSwkMqpdh9 5N8m7tLJvepnbLdB9hx+OJ6lsXAj2UwXiiPkw+bAVuHw0Wb1oiIMd8vj1SEMgU3lZmu4 Q4xux5FFy0e4/4650EwFdDvZ2ZQdQ2J7zEOfR/Op23singujiFN+s2baYe/wdCg2OzWw 7wiQRCPJaE8edpRCXUMOrr0e7rUgFZ1PHZVZLMwuPYoxo+TUuorCSvOzE8rK0wOYikIU Dn/A== X-Gm-Message-State: AOAM530p5KOc+vMOSaVi1FZ2aAYTsBjoOSHzBe9OPzECi87KZlBeceHk Y+oiDqYfAirwVj7+WfgZlqXDNvH8uappeFqt X-Google-Smtp-Source: ABdhPJxtoageBQNYvSk1VtKpcFUVPUrVFQmq32PJxpSAW3BoTHti1Uz9DhnW0LOQD3FUjL5L64RLR2rvuttIZXXf X-Received: from yosry.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:2327]) (user=yosryahmed job=sendgmr) by 2002:a17:90b:4c85:b0:1d4:bc0b:90eb with SMTP id my5-20020a17090b4c8500b001d4bc0b90ebmr2179433pjb.171.1650584685622; Thu, 21 Apr 2022 16:44:45 -0700 (PDT) Date: Thu, 21 Apr 2022 23:44:24 +0000 In-Reply-To: <20220421234426.3494842-1-yosryahmed@google.com> Message-Id: <20220421234426.3494842-3-yosryahmed@google.com> Mime-Version: 1.0 References: <20220421234426.3494842-1-yosryahmed@google.com> X-Mailer: git-send-email 2.36.0.rc2.479.g8af0fa9b8e-goog Subject: [PATCH v4 2/4] selftests: cgroup: return -errno from cg_read()/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 , " =?utf-8?q?Michal_Koutn=C3=BD?= " , Tim Chen , Dan Schatzberg , 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 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Currently, cg_read()/cg_write() returns 0 on success and -1 on failure. Modify them to return the -errno on failure. Signed-off-by: Yosry Ahmed Acked-by: Shakeel Butt --- tools/testing/selftests/cgroup/cgroup_util.c | 44 +++++++++----------- 1 file changed, 19 insertions(+), 25 deletions(-) diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/cgroup_util.c index dbaa7aabbb4a..e6f3679cdcc0 100644 --- a/tools/testing/selftests/cgroup/cgroup_util.c +++ b/tools/testing/selftests/cgroup/cgroup_util.c @@ -19,6 +19,7 @@ #include "cgroup_util.h" #include "../clone3/clone3_selftests.h" +/* Returns read len on success, or -errno on failure. */ static ssize_t read_text(const char *path, char *buf, size_t max_len) { ssize_t len; @@ -26,35 +27,29 @@ static ssize_t read_text(const char *path, char *buf, size_t max_len) fd = open(path, O_RDONLY); if (fd < 0) - return fd; + return -errno; len = read(fd, buf, max_len - 1); - if (len < 0) - goto out; - buf[len] = 0; -out: + if (len >= 0) + buf[len] = 0; + close(fd); - return len; + return len < 0 ? -errno : len; } +/* Returns written len on success, or -errno on failure. */ static ssize_t write_text(const char *path, char *buf, ssize_t len) { int fd; fd = open(path, O_WRONLY | O_APPEND); if (fd < 0) - return fd; + return -errno; len = write(fd, buf, len); - if (len < 0) { - close(fd); - return len; - } - close(fd); - - return len; + return len < 0 ? -errno : len; } char *cg_name(const char *root, const char *name) @@ -87,16 +82,16 @@ char *cg_control(const char *cgroup, const char *control) return ret; } +/* Returns 0 on success, or -errno on failure. */ int cg_read(const char *cgroup, const char *control, char *buf, size_t len) { char path[PATH_MAX]; + ssize_t ret; snprintf(path, sizeof(path), "%s/%s", cgroup, control); - if (read_text(path, buf, len) >= 0) - return 0; - - return -1; + ret = read_text(path, buf, len); + return ret >= 0 ? 0 : ret; } int cg_read_strcmp(const char *cgroup, const char *control, @@ -177,17 +172,15 @@ long cg_read_lc(const char *cgroup, const char *control) return cnt; } +/* Returns 0 on success, or -errno 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) @@ -545,7 +538,8 @@ ssize_t proc_read_text(int pid, bool thread, const char *item, char *buf, size_t else snprintf(path, sizeof(path), "/proc/%d/%s", pid, item); - return read_text(path, buf, size); + size = read_text(path, buf, size); + return size < 0 ? -1 : size; } int proc_read_strstr(int pid, bool thread, const char *item, const char *needle)