From mboxrd@z Thu Jan  1 00:00:00 1970
From: Gao feng <gaofeng-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org>
Subject: Re: Regression wrt mounting /proc in user namespace in 3.13
Date: Mon, 18 Nov 2013 12:52:25 +0800
Message-ID: <52899D09.5080202@cn.fujitsu.com>
References: <20131115164123.GN28794@redhat.com>	<20131116164840.GA4441@mail.hallyn.com>	<20131117030653.GA7670@mail.hallyn.com>
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To: "Serge E. Hallyn" <serge-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org>
Cc: Containers <containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>, "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
List-Id: containers.vger.kernel.org

On 11/18/2013 11:19 AM, Serge E. Hallyn wrote:
> Quoting Serge E. Hallyn (serge-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org):
>> Low on power and no charger, but a quick test printing out if a mount is
>> !S_ISDIR or has nlink !=2 in fs_fully_visible() gives me:
>>
>> [   92.939650] nlink is 1 for ino 8733 (0:3)
>>
>> (that's major 0 minor 3)
> 
> Ok, so that is for binfmt_misc on /proc/sys/fs/binfmt_misc.  The
> underlying directory is empty, and nlink is showing up as 1.
>  
> Can we just get the nlink check changed to check for < 3 instead
> of ==2 ?
> 

I already reported this problem to Eric,hi is working on fix this problem.

nlink is not the right thing to check if a directory is null. since
in all of filesystems, parent dir's nlink is increase only when we
create sub-dir.