From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1VW7xW-0002XJ-DL for mharc-grub-devel@gnu.org; Tue, 15 Oct 2013 12:59:02 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50103) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VW7xO-0002VG-PT for grub-devel@gnu.org; Tue, 15 Oct 2013 12:59:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VW7xI-00046x-5P for grub-devel@gnu.org; Tue, 15 Oct 2013 12:58:54 -0400 Received: from mail-lb0-x236.google.com ([2a00:1450:4010:c04::236]:62166) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VW7xH-00046f-Ts for grub-devel@gnu.org; Tue, 15 Oct 2013 12:58:48 -0400 Received: by mail-lb0-f182.google.com with SMTP id c11so7246772lbj.27 for ; Tue, 15 Oct 2013 09:58:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:subject:message-id:in-reply-to:references:mime-version :content-type:content-transfer-encoding; bh=sCv3QKEu+JeV/m/aJg2TnidPtIBfmmNkV3/BAxkuMBQ=; b=SFh0y7n9LpjkfZcfYPCN8ZVjSSJq6gv1/4NJfdXLMx40USwt9Z+06cxnTY+LDoq0SM zNORHmurRFkA8JWsgqUkRWmuSI/BEFMdArugHMy6qYWqyuV2L4SsWz3b+oERPZVM30I2 RKj+ClSrbDPyU43ZVqDoNGllE2EfM560emrqn/FZ4nRjHAeR5TX85NQAPV8rUQbgKH88 hH0mflkx7dacOpILi6s4ot0TLMELmjdNN9kV/sE2zCJeu2KQ0RbjtzhLWPSRLa7npN25 EsYyIxeFK53nlTlDqYb8GoAIPu8W15QB+DYKNfTZ0eLIXj/AreCNqiaYu0KMkbS+0fOM UmYg== X-Received: by 10.152.8.51 with SMTP id o19mr2313077laa.42.1381856326136; Tue, 15 Oct 2013 09:58:46 -0700 (PDT) Received: from opensuse.site (ppp91-76-150-246.pppoe.mtu-net.ru. [91.76.150.246]) by mx.google.com with ESMTPSA id vk8sm2388026lbb.0.1969.12.31.16.00.00 (version=SSLv3 cipher=RC4-SHA bits=128/128); Tue, 15 Oct 2013 09:58:45 -0700 (PDT) Date: Tue, 15 Oct 2013 20:58:44 +0400 From: Andrey Borzenkov To: grub-devel@gnu.org Subject: Re: booting btrfs Message-ID: <20131015205844.661393b1@opensuse.site> In-Reply-To: References: <0C284942-C2D0-4520-93B1-3982E6AA38DF@colorremedies.com> <525AF8CD.7050100@gmail.com> <525B2D55.8060502@gmail.com> <339EF7EB-F50A-47F6-99BA-F46ABFECCF74@colorremedies.com> <20131014092807.6917958c@opensuse.site> <3D77CF50-285F-42C2-9325-47AC5ACF5FDC@colorremedies.com> <525C4615.5080803@gmail.com> <04468BB2-5F2D-47BA-8CFC-7C5604FBE315@colorremedies.com> <525C5902.3050104@gmail.com> <20131015063327.4f44ced2@opensuse.site> X-Mailer: Claws Mail 3.9.2 (GTK+ 2.24.18; x86_64-suse-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=KOI8-R Content-Transfer-Encoding: 8bit X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2a00:1450:4010:c04::236 X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list Reply-To: The development of GNU GRUB List-Id: The development of GNU GRUB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 15 Oct 2013 16:59:00 -0000 В Mon, 14 Oct 2013 21:12:06 -0600 Chris Murphy пишет: > > So actually, this is a bit more than somewhat messy, whether the prefix should be formatted relative to the default subvolume, or absolute from top level 5 subvolume. It depends on the use case. > > So just like '-o subvol=root' has a different meaning than '-o subvol=/root' there is a difference between prefix=(hd0,msdos1)boot/grub/ and prefix=(hd0,msdos1)/boot/grub/ > I do not know whether it was the case in the past, but today there is *no* difference between using absolute or relative form. As I already said, internally btrfs mounts top level and starts from there anyway. linux-xtd6:/mnt # btrfs subvolume list /mnt ID 256 gen 7 top level 5 path dir1/sub1 ID 257 gen 7 top level 5 path dir2/sub2 linux-xtd6:/mnt # btrfs subvolume get-default /mnt ID 256 gen 7 top level 5 path dir1/sub1 linux-xtd6:~ # umount /mnt linux-xtd6:~ # mount /dev/sdb /mnt linux-xtd6:~ # ls -l /mnt total 0 -rw-r--r-- 1 root root 0 Oct 15 16:50 I am subvolume 1 linux-xtd6:~ # umount /mnt linux-xtd6:~ # mount -o subvol=/dir2/sub2 /dev/sdb /mnt linux-xtd6:~ # ls -l /mnt total 0 -rw-r--r-- 1 root root 0 Oct 15 16:50 I am subvolume 2 linux-xtd6:~ # umount /mnt linux-xtd6:~ # mount -o subvol=dir2/sub2 /dev/sdb /mnt linux-xtd6:~ # ls -l /mnt total 0 -rw-r--r-- 1 root root 0 Oct 15 16:50 I am subvolume 2 I'm not sure when and how top level may become != 5.