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From:   Roman Gushchin <guro@fb.com>
To:     Tejun Heo <tj@kernel.org>
CC:     Peng Wang <rocking@whu.edu.cn>,
        "lizefan@huawei.com" <lizefan@huawei.com>,
        "hannes@cmpxchg.org" <hannes@cmpxchg.org>,
        "cgroups@vger.kernel.org" <cgroups@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] cgroup: minor tweak for logic to get cgroup css
Thread-Topic: [PATCH] cgroup: minor tweak for logic to get cgroup css
Thread-Index: AQHVMUV9d2o/bgH9tUqXCEtcJHSYqabA9ciAgAANIwA=
Date:   Mon, 8 Jul 2019 17:29:49 +0000
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On Mon, Jul 08, 2019 at 09:42:43AM -0700, Tejun Heo wrote:
> On Wed, Jul 03, 2019 at 10:07:49AM +0800, Peng Wang wrote:
> > We could only handle the case that css exists
> > and css_try_get_online() fails.
>=20
> As css_tryget_online() can't handle NULL input, this is a bug fix.
> Can you please clarify that in the description?

-       if (!css || !css_tryget_online(css))
+       if (css && !css_tryget_online(css))

If css =3D=3D NULL, !css is true, and the second part of the || statement
will not be evaluated. So it's not a bug fix.

Thanks!