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From: Zefan Li <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
To: Ma Shimiao
	<mashimiao.fnst-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org>,
	"cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: questions about cgroup devices
Date: Mon, 23 Jan 2017 15:35:33 +0800	[thread overview]
Message-ID: <5885B245.2030901@huawei.com> (raw)
In-Reply-To: <d28bc963-4936-6574-c606-d2b0c475f0c9-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org>

On 2017/1/23 15:16, Ma Shimiao wrote:
> Hi all,
> 
> I think I met a problem about cgroup devices.
> 
> The following is my detailed operations:
> 
> # cd /sys/fs/cgroup/devices/
> # mkdir test
> # echo "c 1:3 rw" > test/devices.deny
> # cat test/devices.list 
> a *:* rwm
> 
> It seems my setting does not react in devices.list.
> 
> But in another terminal, /dev/null is really limited to access.
> $ sudo cgexec -g devices:test dd if=/dev/zero of=/dev/null bs=1M count=128
> dd: failed to open '/dev/null': Operation not permitted
> 
> So, is this a bug of cgroup devices?
> 

It's not a bug. It's a feature introduced by commit ad676077a2ae4af4bb.
That said, I don't like this feature at all, because it's very confusing,
and obviously you are confused.

  parent reply	other threads:[~2017-01-23  7:35 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-01-23  7:16 questions about cgroup devices Ma Shimiao
     [not found] ` <d28bc963-4936-6574-c606-d2b0c475f0c9-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org>
2017-01-23  7:35   ` Zefan Li [this message]
     [not found]     ` <5885B245.2030901-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2017-01-23  7:51       ` Ma Shimiao
2017-01-23  7:58       ` Ma Shimiao

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