From: Tejun Heo <tj@kernel•org>
To: Li Zefan <lizefan@huawei•com>
Cc: Li Zhong <zhong@linux•vnet.ibm.com>,
linux-next list <linux-next@vger•kernel.org>
Subject: Re: [RFC PATCH next]cgroup: use css_get() in cgroup_create() to check CSS_ROOT
Date: Fri, 16 Aug 2013 10:58:05 -0400 [thread overview]
Message-ID: <20130816145805.GE2505@htj.dyndns.org> (raw)
In-Reply-To: <520DFBF2.5050903@huawei.com>
On Fri, Aug 16, 2013 at 06:16:18PM +0800, Li Zefan wrote:
> On 2013/8/16 17:57, Li Zhong wrote:
> > It seems that the root css doesn't have refcnt allocated(not needed?),
> > and would cause the booting error attached.
> >
> > This patch tries to use css_get() to not increase the refcnt if parent
> > is root.
> ...
> > diff --git a/kernel/cgroup.c b/kernel/cgroup.c
> > index 723194f..781f8cd 100644
> > --- a/kernel/cgroup.c
> > +++ b/kernel/cgroup.c
> > @@ -4485,7 +4485,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
> > struct cgroup_subsys_state *css = css_ar[ss->subsys_id];
> >
> > dget(dentry);
> > - percpu_ref_get(&css->parent->refcnt);
> > + css_get(css->parent);
>
> We use css_put() to drop this refcnt, so it makes sense to use css_get()
> for consistency.
>
> Acked-by: Li Zefan <lizefan@huawei•com>
Heh, this doesn't trigger on my test setup for some reason. Applied.
Thanks a lot.
--
tejun
prev parent reply other threads:[~2013-08-16 14:58 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-16 9:57 [RFC PATCH next]cgroup: use css_get() in cgroup_create() to check CSS_ROOT Li Zhong
2013-08-16 10:16 ` Li Zefan
2013-08-16 14:58 ` Tejun Heo [this message]
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