From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?utf-8?B?SsO2cm4=?= Engel Subject: Re: [RFC] The reflink(2) system call v4. Date: Tue, 12 May 2009 13:31:52 +0200 Message-ID: <20090512113152.GE6585@logfs.org> References: <1241331303-23753-1-git-send-email-joel.becker@oracle.com> <20090507221535.GA31624@mail.oracle.com> <4A039FF8.7090807@hp.com> <20090508031018.GB8611@mail.oracle.com> <20090511204011.GB30293@mail.oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: jim owens , jmorris@namei.org, ocfs2-devel@oss.oracle.com, viro@zeniv.linux.org.uk, mtk.manpages@gmail.com, linux-security-module@vger.kernel.org, linux-fsdevel@vger.kernel.org To: Joel Becker Return-path: Received: from lazybastard.de ([212.112.238.170]:58825 "EHLO longford.logfs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755193AbZELLcQ (ORCPT ); Tue, 12 May 2009 07:32:16 -0400 Content-Disposition: inline In-Reply-To: <20090511204011.GB30293@mail.oracle.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Mon, 11 May 2009 13:40:11 -0700, Joel Becker wrote: > > Here's v4 of reflink(). If you have the privileges, you get the > full snapshot. If you don't, you must have read access, and then you > get the entire snapshot (data and extended attributes) except that th= e > security context is reinitialized. That's it. It fits with most of = the > other ops, and it's a clean degradation. Let me see if I understand this correctly. File "/tmp/foo" belongs to Joel, file "/tmp/bar" belongs to Joern. Everyone has read access to those files. Now if you reflink them to your home directory, both file= s belong to you. If I reflink them to my home directory, both files belong to me. And if root reflinks them to /root, one file belongs to Joel, the other to Joern. Is that correct? Because if it is, I would call that behaviour rather confusing. A system call that behaves differently depending on who calls it - or on whether the binary is installed suid root - is something I would lik= e to avoid. J=C3=B6rn --=20 A surrounded army must be given a way out. -- Sun Tzu -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel= " in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html