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From: Hao Luo <haoluo@google.com>
To: Tejun Heo <tj@kernel.org>
Cc: "Yosry Ahmed" <yosryahmed@google.com>,
	"Michal Koutný" <mkoutny@suse.com>,
	"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
	Cgroups <cgroups@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
	"Aditya Kali" <adityakali@google.com>,
	"Serge Hallyn" <serge.hallyn@canonical.com>,
	"Roman Gushchin" <roman.gushchin@linux.dev>,
	"Yonghong Song" <yhs@fb.com>,
	"Muneendra Kumar" <muneendra.kumar@broadcom.com>
Subject: Re: [PATCH 4/4] cgroup/bpf: Honor cgroup NS in cgroup_iter for ancestors
Date: Mon, 29 Aug 2022 11:02:36 -0700	[thread overview]
Message-ID: <CA+khW7jZCN54nUonNLp59fTAqOtAk_Ror+PgrLBfufRcE-CnFQ@mail.gmail.com> (raw)
In-Reply-To: <Ywz8J70t3508J62n@slm.duckdns.org>

On Mon, Aug 29, 2022 at 10:49 AM Tejun Heo <tj@kernel.org> wrote:
>
> On Mon, Aug 29, 2022 at 10:30:45AM -0700, Yosry Ahmed wrote:
> > > I'd like to clarify, if a process A in a broad cgroup ns sets up a BPF
> > > cgroup iterator, exposes it via bpffs and than a process B in a narrowed
> > > cgroup ns (which excludes the origin cgroup) wants to traverse the
> > > iterator, should it fail straight ahead (regardless of iter order)?
> > > The alternative would be to allow self-dereference but prohibit any
> > > iterator moves (regardless of order).
> > >
> >
> > imo it should fail straight ahead, but maybe others (Tejun? Hao?) have
> > other opinions here.
>
> Yeah, I'd prefer it to fail right away as that's simple and gives us the
> most choices for the future.
>

Thanks Michal for fixing the cgroup iter use case! I agree that
failing straight ahead is better. I don't envision a use case that
wants the alternative.

> Thanks.
>
> --
> tejun

  reply	other threads:[~2022-08-29 18:02 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-26 16:52 [PATCH 0/4] Honor cgroup namespace when resolving cgroup id Michal Koutný
2022-08-26 16:52 ` Michal Koutný
2022-08-26 16:52 ` [PATCH 1/4] cgroup: Honor caller's cgroup NS when resolving path Michal Koutný
2022-08-26 16:52   ` Michal Koutný
2022-08-26 16:52 ` [PATCH 2/4] cgroup: cgroup: Honor caller's cgroup NS when resolving cgroup id Michal Koutný
2022-08-26 16:52   ` Michal Koutný
2022-08-26 16:52 ` [PATCH 3/4] cgroup: Homogenize cgroup_get_from_id() return value Michal Koutný
2022-08-26 16:52   ` Michal Koutný
2022-08-26 16:52 ` [PATCH 4/4] cgroup/bpf: Honor cgroup NS in cgroup_iter for ancestors Michal Koutný
2022-08-26 16:52   ` Michal Koutný
2022-08-26 17:41   ` Yosry Ahmed
2022-08-29 12:59     ` Michal Koutný
2022-08-29 12:59       ` Michal Koutný
2022-08-29 17:30       ` Yosry Ahmed
2022-08-29 17:30         ` Yosry Ahmed
2022-08-29 17:49         ` Tejun Heo
2022-08-29 18:02           ` Hao Luo [this message]
2022-08-26 20:59 ` [PATCH 0/4] Honor cgroup namespace when resolving cgroup id Tejun Heo
2022-08-26 21:08 ` Tejun Heo

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