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[209.132.180.67]) by mx.google.com with ESMTP id w2si548989pfi.183.2019.07.02.19.17.53; Tue, 02 Jul 2019 19:18:07 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728129AbfGCCRA (ORCPT + 99 others); Tue, 2 Jul 2019 22:17:00 -0400 Received: from zg8tmtyylji0my4xnjqunzqa.icoremail.net ([162.243.164.74]:60134 "HELO zg8tmtyylji0my4xnjqunzqa.icoremail.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1728112AbfGCCQ6 (ORCPT ); Tue, 2 Jul 2019 22:16:58 -0400 X-Greylist: delayed 380 seconds by postgrey-1.27 at vger.kernel.org; Tue, 02 Jul 2019 22:16:57 EDT Received: from localhost (unknown [111.202.192.3]) by email1 (Coremail) with SMTP id AQBjCgDXpmB2Dhxd6PNCAA--.52124S2; Wed, 03 Jul 2019 10:10:18 +0800 (CST) From: Peng Wang To: tj@kernel.org, lizefan@huawei.com, hannes@cmpxchg.org Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Peng Wang Subject: [PATCH] cgroup: minor tweak for logic to get cgroup css Date: Wed, 3 Jul 2019 10:07:49 +0800 Message-Id: <20190703020749.22988-1-rocking@whu.edu.cn> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID: AQBjCgDXpmB2Dhxd6PNCAA--.52124S2 X-Coremail-Antispam: 1UD129KBjvdXoW7Xry8CF1ftr1UuFWxArykGrg_yoWxCrb_Aw 1Iva12gry8Aw1jkr4qgws5XFWkKF4YgF1vvr4UtFy7JFyUtFs8t34fJF15JFsxuFn3XryD JrW3WrykGrn7ujkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbckFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8w A2z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j 6F4UJwA2z4x0Y4vEx4A2jsIE14v26F4UJVW0owA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gc CE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E 2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJV W8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lc2xSY4AK67AK6r4U MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr 0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUAVWUtwCIc40Y0x0E wIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVWUJV W8JwCI42IY6xAIw20EY4v20xvaj40_WFyUJVCq3wCI42IY6I8E87Iv67AKxVWUJVW8JwCI 42IY6I8E87Iv6xkF7I0E14v26r1j6r4UYxBIdaVFxhVjvjDU0xZFpf9x0JUgVyxUUUUU= X-CM-SenderInfo: qsqrijaqrviiqqxyq4lkxovvfxof0/ Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We could only handle the case that css exists and css_try_get_online() fails. Signed-off-by: Peng Wang --- kernel/cgroup/cgroup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index bf9dbffd46b1..a988d77f6c6d 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -488,7 +488,7 @@ static struct cgroup_subsys_state *cgroup_tryget_css(struct cgroup *cgrp, rcu_read_lock(); css = cgroup_css(cgrp, ss); - if (!css || !css_tryget_online(css)) + if (css && !css_tryget_online(css)) css = NULL; rcu_read_unlock(); -- 2.19.1