From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from list by lists.gnu.org with archive (Exim 4.71)
	id 1aHFyQ-0005rQ-PI
	for mharc-grub-devel@gnu.org; Thu, 07 Jan 2016 14:11:50 -0500
Received: from eggs.gnu.org ([2001:4830:134:3::10]:42202)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <arvidjaar@gmail.com>) id 1aHFyO-0005rI-HN
	for grub-devel@gnu.org; Thu, 07 Jan 2016 14:11:49 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <arvidjaar@gmail.com>) id 1aHFyL-0007lJ-9I
	for grub-devel@gnu.org; Thu, 07 Jan 2016 14:11:48 -0500
Received: from mail-lf0-x229.google.com ([2a00:1450:4010:c07::229]:34475)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <arvidjaar@gmail.com>) id 1aHFyL-0007lC-1Q
	for grub-devel@gnu.org; Thu, 07 Jan 2016 14:11:45 -0500
Received: by mail-lf0-x229.google.com with SMTP id y184so338394646lfc.1
	for <grub-devel@gnu.org>; Thu, 07 Jan 2016 11:11:44 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113;
	h=to:from:subject:message-id:date:user-agent:mime-version
	:content-type:content-transfer-encoding;
	bh=rcTlDncND5WMqCk/+wY73pJxMVv0LAEPGyhY0cj1pYE=;
	b=Hdo348Ckft2wjvGL0FKk4DZhDU+eP4b9I3kwSmGV88vLwpBTQgJ5KK80S4Ln2dUA+H
	JT5U8GUXq3NjRX2konVQ3IkvADLmq48j3as5Mh3vTZUnCBEhgO4vfCs8iabz8z2mNKsv
	cUowSvFP4pPuy8Feb60EwOEFvwQpHcEs4Z6FaSVDdCDRn3t7TbZxOiQN887E3OVCgj3w
	uUV+9N69kE/YMLdRUnY73nRaIAyejJw72oo1ZjlV9sYu/zxIEaKymgICzgNEHfNC/cJU
	H09qceId8m4XTn4x4DZuaXiWVhUV/Xsymh2QphytoqGPVDl+ciDyoknt6E3ABhVdwdkV
	yOSg==
X-Received: by 10.25.0.84 with SMTP id 81mr26439233lfa.132.1452193904462;
	Thu, 07 Jan 2016 11:11:44 -0800 (PST)
Received: from [192.168.1.41] (ppp91-76-25-247.pppoe.mtu-net.ru.
	[91.76.25.247]) by smtp.gmail.com with ESMTPSA id
	m75sm18171303lfg.15.2016.01.07.11.11.43
	(version=TLSv1/SSLv3 cipher=OTHER);
	Thu, 07 Jan 2016 11:11:43 -0800 (PST)
To: The development of GNU GRUB <grub-devel@gnu.org>,
	linux-btrfs@vger.kernel.org
From: Andrei Borzenkov <arvidjaar@gmail.com>
Subject: btrfs trim erases bootloader area
X-Enigmail-Draft-Status: N1110
Message-ID: <568EB86F.7070800@gmail.com>
Date: Thu, 7 Jan 2016 22:11:43 +0300
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101
	Thunderbird/38.4.0
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit
X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic]
X-Received-From: 2a00:1450:4010:c07::229
X-BeenThere: grub-devel@gnu.org
X-Mailman-Version: 2.1.14
Precedence: list
Reply-To: The development of GNU GRUB <grub-devel@gnu.org>
List-Id: The development of GNU GRUB <grub-devel.gnu.org>
List-Unsubscribe: <https://lists.gnu.org/mailman/options/grub-devel>,
	<mailto:grub-devel-request@gnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/archive/html/grub-devel>
List-Post: <mailto:grub-devel@gnu.org>
List-Help: <mailto:grub-devel-request@gnu.org?subject=help>
List-Subscribe: <https://lists.gnu.org/mailman/listinfo/grub-devel>,
	<mailto:grub-devel-request@gnu.org?subject=subscribe>
X-List-Received-Date: Thu, 07 Jan 2016 19:11:49 -0000

As discussed on opensuse-factory list, running fstrim on btrfs erases
bootloader area, rendering system unbootable. See

https://lists.opensuse.org/opensuse-factory/2016-01/msg00067.html
https://lists.opensuse.org/opensuse-factory/2016-01/msg00090.html

and follow-ups that demonstrate that beginning of device gets zeroed out.

Not sure what we can do, but from GRUB side I can only see disabling
embedding support on btrfs entirely.