From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from syrinx.knorrie.org ([82.94.188.77]:37178 "EHLO syrinx.knorrie.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757293AbdIILNp (ORCPT ); Sat, 9 Sep 2017 07:13:45 -0400 Subject: Re: generic name for volume and subvolume root? To: Hugo Mills , Qu Wenruo , linux-btrfs@vger.kernel.org, framstag@rus.uni-stuttgart.de References: <20170909083551.GC22060@rus.uni-stuttgart.de> <48008a58-a82e-d9f7-327e-eeb905e18aa1@gmx.com> <20170909104845.GW12642@rus.uni-stuttgart.de> <9911ae20-6181-5ce2-0374-e601a1034c4a@gmx.com> <20170909110632.GG23980@carfax.org.uk> From: Hans van Kranenburg Message-ID: Date: Sat, 9 Sep 2017 13:13:43 +0200 MIME-Version: 1.0 In-Reply-To: <20170909110632.GG23980@carfax.org.uk> Content-Type: text/plain; charset=utf-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 09/09/2017 01:06 PM, Hugo Mills wrote: > On Sat, Sep 09, 2017 at 06:58:38PM +0800, Qu Wenruo wrote: >> >> >> On 2017年09月09日 18:48, Ulli Horlacher wrote: >>> On Sat 2017-09-09 (18:40), Qu Wenruo wrote: >>> >>>>> Is there a generic name for both volume and subvolume root? >>>> >>>> Nope, subvolume (including snapshot) is not distinguished by its >>>> filename/path/directory name. >>>> >>>> And you can only do snapshot on subvolume (snapshot is one kind of >>>> subvolume) boundary. >>> >>> So, I can name a btrfs root volume also btrfs subvolume? >> >> Yes, root volume is also a subvolume, so just call "btrfs root volume" >> a "subvolume". > > I find it's best to avoid the word "root" entirely, as it's got > several meanings, and it tends to get confusing in conversation. > Instead, we have: > > - "the top level" (subvolid=5) > - "/" (what you see at / in your running system) > - "/@" or similar names > (the subvolume that's mounted at /) > >>> I am talking about documentation, not coding! >>> >>> I just want yo use the correct terms. >> >> If you're referring to the term, I think subvolume is good enough. >> Which represents your original term, "directories one can snapshot". >> >> >> For the whole btrfs "volume", I would just call it "filesystem" to >> avoid the name "volume" or "subvolume" at all. > > Yes, it's a filesystem. (Although that does occasionally cause > confusion between "the conceptual filesystem implemented by btrfs.ko" > and "the concrete filesystem stored on /dev/sda1", but it's generally > far less confusing than the overloading of "root"). Yes, because every subvolume is a filesystem root! :-D https://i.imgur.com/2VzmC.gif -- Hans van Kranenburg