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Date: Tue, 31 Jan 2012 11:54:47 +0000
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: ebiederm@xmission.com (Eric W. Biederman)
Cc: Greg KH <greg@kroah.com>, Jiri Slaby <jslaby@suse.cz>,
        LKML <linux-kernel@vger.kernel.org>,
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Subject: Re: sysfs regression: wrong link counts
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On Mon, 30 Jan 2012 19:45:10 -0800
ebiederm@xmission.com (Eric W. Biederman) wrote:

> Alan Cox <alan@lxorguk.ukuu.org.uk> writes:
> 
> >> Isn't there some other "proper" way of doing this in userspace, or is
> >> this really the correct way?
> >
> > You can look at the S_IFMT bits and stuff however link count indicating
> > number of subdirectories is a standard Unix thing and used by many quite
> > mundane tools as an optimisation.
> 
> Those tools for a decade or better all know to treat nlink == 1 as the
> case where the optimization does not apply.

Most of the do. but as has been demonstrated here - not all