From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Waychison Subject: Re: [PATCH 25/28] VFS: statfs(64) shouldn't follow last component symlink Date: Mon, 25 Oct 2004 11:21:56 -0400 Sender: linux-fsdevel-owner@vger.kernel.org Message-ID: <417D1A14.5010601@sun.com> References: <10987158413464@sun.com> <10987158711277@sun.com> <20041025151405.GA1740@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7BIT Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, raven@themaw.net Return-path: Received: from nwkea-mail-1.sun.com ([192.18.42.13]:21736 "EHLO nwkea-mail-1.sun.com") by vger.kernel.org with ESMTP id S261957AbUJYPWT (ORCPT ); Mon, 25 Oct 2004 11:22:19 -0400 Received: from phys-mpk-2 ([129.146.11.82]) by nwkea-mail-1.sun.com (8.12.10/8.12.9) with ESMTP id i9PFLvs9023867 for ; Mon, 25 Oct 2004 08:22:18 -0700 (PDT) Received: from conversion-daemon.mpk-mail1.sfbay.sun.com by mpk-mail1.sfbay.sun.com (iPlanet Messaging Server 5.2 HotFix 1.24 (built Dec 19 2003)) id <0I6500501BVYHM@mpk-mail1.sfbay.sun.com> (original mail from Michael.Waychison@Sun.COM) for linux-fsdevel@vger.kernel.org; Mon, 25 Oct 2004 08:22:06 -0700 (PDT) In-reply-to: <20041025151405.GA1740@infradead.org> To: Christoph Hellwig List-Id: linux-fsdevel.vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Christoph Hellwig wrote: > On Mon, Oct 25, 2004 at 10:51:11AM -0400, Mike Waychison wrote: > >>Mount-related userspace tools will require the ability to detect whether what >>looks like a regular directory is actually a autofs trigger. To handle this, >>tools can statfs a given directory and check to see if statfs->f_type == >>AUTOFSNG_SUPER_MAGIC before walking into the directory (and causing the a >>filesystem to automount). >> >>To make this happen, we cannot allow statfs to follow_link. >> >>NOTE: This may break any userspace that assumes it can statfs across a >>last-component symlink. I can't think of any real world breakage however, as >>mount(8) will drop the real path in /etc/mtab and /proc/mounts will always >>show the true path. > > > Which means it's vetoed. It's a big change in syscall semantics. And > propabably breaks SuS (for statvfs(3) which requires full symlink > resolution when it just refers to a path on the filesystem. > Ya, I figured that would be the case. What do folks think about a lstatfs(64)? - -- Mike Waychison Sun Microsystems, Inc. 1 (650) 352-5299 voice 1 (416) 202-8336 voice ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NOTICE: The opinions expressed in this email are held by me, and may not represent the views of Sun Microsystems, Inc. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.5 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFBfRoUdQs4kOxk3/MRAgHoAKCApqvkE2hgLAJKXDkLWWJE7BqevgCfQlh9 BxBlFSMUPoo1VyOcntae7Y0= =rR8G -----END PGP SIGNATURE-----