From: Tejun Heo Subject: [PATCH 4/4] cgroup: use release_agent_path_lock in cgroup_release_agent_show() Date: Tue, 6 May 2014 07:50:44 -0400 Message-ID: <1399377044-29873-5-git-send-email-tj@kernel.org> References: <1399377044-29873-1-git-send-email-tj@kernel.org> Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=1bPYtvX20j7w0fr/ijILVAzVwJAaQiq+CFn/GmslBIU=; b=qUwWFTIGlkKoepuAqbFrDZb5bViCQrjeTHFXUFExPReUqfmvqJuBoX1yABWBaj3Syv vNTPLVQIsUINeUA5WoAijrHjUYBiDgFAQq27Rfh3xUyHn2cfOau+1n5HPRjQCn3QyVaH g4PNn+YiUZcJvMdJjmGXjpqpjAjC3XMunLW7VjRNKLx4G75yTq99new1xWA5C6kTYLpd pRqwy2yDxFe6J7ktzHfE4w9KOnVmn1PxewuqRpJPVaW6zutgxFSoi2gh6LeJ5BUIv7hx BdOAXDezTubOPcrEXSYludFIJK0CA0QhOA+JnCT5PSv3Y7G6HTGUncWuGGro233zUbWH xLag== In-Reply-To: <1399377044-29873-1-git-send-email-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lizefan@huawei.com Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Tejun Heo release_path is now protected by release_agent_path_lock to allow accessing it without grabbing cgroup_mutex; however, cgroup_release_agent_show() was still grabbing cgroup_mutex. Let's convert it to release_agent_path_lock so that we don't have to worry about this one for the planned locking updates. Signed-off-by: Tejun Heo --- kernel/cgroup.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 3ced79a..57c2021 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2373,11 +2373,10 @@ static int cgroup_release_agent_show(struct seq_file *seq, void *v) { struct cgroup *cgrp = seq_css(seq)->cgroup; - if (!cgroup_lock_live_group(cgrp)) - return -ENODEV; + spin_lock(&release_agent_path_lock); seq_puts(seq, cgrp->root->release_agent_path); + spin_unlock(&release_agent_path_lock); seq_putc(seq, '\n'); - mutex_unlock(&cgroup_mutex); return 0; } -- 1.9.0