From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joel Becker Subject: Re: [RFC] The reflink(2) system call v2. Date: Mon, 11 May 2009 16:46:24 -0700 Message-ID: <20090511234624.GC28209@mail.oracle.com> References: <1241331303-23753-1-git-send-email-joel.becker@oracle.com> <20090507221535.GA31624@mail.oracle.com> <4A039FF8.7090807@hp.com> <20090511204924.GC30293@mail.oracle.com> <4A08AB5D.7090706@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel@vger.kernel.org, jmorris@namei.org, ocfs2-devel@oss.oracle.com, viro@zeniv.linux.org.uk, mtk.manpages@gmail.com, linux-security-module@vger.kernel.org To: jim owens Return-path: Content-Disposition: inline In-Reply-To: <4A08AB5D.7090706@hp.com> Sender: linux-security-module-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Mon, May 11, 2009 at 06:49:01PM -0400, jim owens wrote: > Joel Becker wrote: >> On Thu, May 07, 2009 at 10:59:04PM -0400, jim owens wrote: >>> - fix the >>> + if (S_ISDIR(inode->i_mode)) >>> + return -EPERM; >>> >>> to be an ISREG check unless you have an argument for >>> special files and symlinks being COWed. >> >> Jim, if you have a real problem this prevents, I'm all ears. >> And if others concur that restricting it to regular files is the right >> way to go, I can be convinced. > > My only problem was my past experience on non-Linux systems > where once we said it works for multiple file types, we had > to support that forever across all filesystems. We could add > support for more types but not eliminate supported ones. Someone else pointed out that a naive user might reflink a block device file and expect the device contents to be copied-on-write. Obviously wrong if you understand filesystems, but let's just prevent that misunderstanding. S_ISREG() it is. Joel -- "All alone at the end of the evening When the bright lights have faded to blue. I was thinking about a woman who had loved me And I never knew" Joel Becker Principal Software Developer Oracle E-mail: joel.becker@oracle.com Phone: (650) 506-8127