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From: David Howells <dhowells@redhat.com>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: dhowells@redhat.com,
	Linus Torvalds <torvalds@linux-foundation.org>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	LSM List <linux-security-module@vger.kernel.org>,
	Miklos Szeredi <miklos@szeredi.hu>
Subject: Re: [RFC] readlink()-related oddities
Date: Fri, 20 Nov 2015 10:00:41 +0000	[thread overview]
Message-ID: <22334.1448013641@warthog.procyon.org.uk> (raw)
In-Reply-To: <20151120025749.GJ22011@ZenIV.linux.org.uk>

Al Viro <viro@ZenIV.linux.org.uk> wrote:

> How would those tools know that this particular pathname _is_ a magical
> symlink?  Sure, if you see a symlink with body that starts with % or #,
> you could figure out that it's not a regular one and go parse the body,
> but for stat(2) it looks like a directory.  Do those tools call readlink()
> on every directory they spot on AFS volume?  David?

It has to be a directory so that you can mount on it.  If you look in /afs on
an OpenAFS client filesystem it appears as a symlink to somewhere under /afs/
because they can't do the in-kernel mounting (it's GPL-only on Linux).

David

  parent reply	other threads:[~2015-11-20 10:00 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-19 23:26 [RFC] readlink()-related oddities Al Viro
2015-11-20  2:13 ` Linus Torvalds
2015-11-20  2:57   ` Al Viro
2015-11-20  3:09     ` Linus Torvalds
2015-11-20  3:16       ` Linus Torvalds
2015-11-20  3:24         ` Al Viro
2015-11-20 10:00   ` David Howells [this message]
2015-11-20  9:59 ` David Howells
2015-11-20 16:08   ` Al Viro
2015-11-20 16:26   ` David Howells
2015-11-20 22:33   ` Al Viro

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