linux-kernel - Re: [PATCH 1/8] cgroup: implement cgroup_is

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 8 Apr 2013 08:39:42 -0700
From:	Tejun Heo <tj@...nel.org>
To:	Li Zefan <lizefan@...wei.com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Glauber Costa <glommer@...allels.com>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	Michal Hocko <mhocko@...e.cz>,
	Johannes Weiner <hannes@...xchg.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Cgroups <cgroups@...r.kernel.org>, linux-mm@...ck.org
Subject: Re: [PATCH 1/8] cgroup: implement cgroup_is_ancestor()

Hello, Li.

On Mon, Apr 08, 2013 at 04:20:11PM +0800, Li Zefan wrote:
> +/**
> + * cgroup_is_ancestor - test "root" cgroup is an ancestor of "child"
> + * @child: the cgroup to be tested.
> + * @root: the cgroup supposed to be an ancestor of the child.

Please explain locking in the comment.  (I know it only requires both
cgroups to be accessible but being explicit is nice.)

> + * Returns true if "root" is an ancestor of "child" in its hierarchy.
> + */
> +bool cgroup_is_ancestor(struct cgroup *child, struct cgroup *root)

s/root/ancestor/

> +{
> +	int depth = child->depth;
> +
> +	if (depth < root->depth)
> +		return false;
> +
> +	while (depth-- != root->depth)
> +		child = child->parent;

Just walk up till it meets the ancestor or reaches root.  Why bother
with depth?

Thanks.

-- 
tejun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/