From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from linux-libre.fsfla.org ([208.118.235.54]:40745 "EHLO linux-libre.fsfla.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753111Ab3HDPIV (ORCPT ); Sun, 4 Aug 2013 11:08:21 -0400 Received: from freie (home.lxoliva.fsfla.org [172.31.160.22]) by linux-libre.fsfla.org (8.14.4/8.14.4/Debian-2ubuntu2) with ESMTP id r74Ew5BE017292 for ; Sun, 4 Aug 2013 14:58:05 GMT From: Alexandre Oliva To: Jerome Haltom Cc: Linux Btrfs Subject: Re: Q: Why subvolumes? References: <20130723150620.GG20517@carfax.org.uk> <51EEC1BD.9030001@gmail.com> <20130723193013.GI20517@carfax.org.uk> Date: Sun, 04 Aug 2013 11:56:56 -0300 In-Reply-To: (Jerome Haltom's message of "Tue, 23 Jul 2013 14:43:13 -0500") Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Jul 23, 2013, Jerome Haltom wrote: > Why not just create the new dev_id on the destination snapshot of any > directory? That way the snapshot can share inodes with is source. Agreed. Nothing stops us from implementing snapshotting of any directory whatsoever: all it takes is to take a snapshot of the subvolume enclosing the directory we want to snapshot, removing everything that's not in the requested directory from the snapshot, and making that directory the root of the snapshot. The only tricky bit here AFAICT is to arrange for the non-snapshotted subtree components to be cleaned up in background. If we had some primitive to unlink an entire subtree and clean it up in background we could use that. -- Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/ You must be the change you wish to see in the world. -- Gandhi Be Free! -- http://FSFLA.org/ FSF Latin America board member Free Software Evangelist Red Hat Brazil Compiler Engineer