From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamie Lokier Subject: Re: [PATCH 1/3] fs: Document the reflink(2) system call. Date: Tue, 5 May 2009 16:32:17 +0100 Message-ID: <20090505153217.GA31100@shareable.org> References: <1241331303-23753-1-git-send-email-joel.becker@oracle.com> <1241331303-23753-2-git-send-email-joel.becker@oracle.com> <20090505010703.GA12731@shareable.org> <20090505071608.GB10258@mail.oracle.com> <20090505130114.GD17486@mit.edu> <20090505131907.GF25328@shareable.org> <20090505142102.GE17486@mit.edu> 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 To: Theodore Tso Return-path: Received: from mail2.shareable.org ([80.68.89.115]:57789 "EHLO mail2.shareable.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750915AbZEEPcS (ORCPT ); Tue, 5 May 2009 11:32:18 -0400 Content-Disposition: inline In-Reply-To: <20090505142102.GE17486@mit.edu> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Theodore Tso wrote: > 1) If someone other than the owner of a file uses reflink to "make a > copy" of the file, is it new inode, with the new inode number, owned > by the original owner (making it look more like a link), or owned by > the person creating the reflink (making it look more like a copy). > > 2) Does changing the metadata --- atime, user/group ownership, ctime, > etc., break the COW link and cause a copy? > > (2) could be a per-filesystem implementation detail, but (1) goes to > the semantics of the how the reflink() system call will work, so I > think we need to have a common answer which is the same across all > filesystems. I agree on both. user/group ownership seems to raise the most questions. Can we settle the hopefully simpler question of ctime, atime, mode changes? -- Jamie