From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-fsdevel-owner@vger.kernel.org>
Received: from verein.lst.de ([213.95.11.211]:40906 "EHLO newverein.lst.de"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1752247AbdHPPSE (ORCPT <rfc822;linux-fsdevel@vger.kernel.org>);
        Wed, 16 Aug 2017 11:18:04 -0400
Date: Wed, 16 Aug 2017 17:18:03 +0200
From: Christoph Hellwig <hch@lst.de>
To: Lukas Czerner <lczerner@redhat.com>
Cc: linux-fsdevel@vger.kernel.org, axboe@kernel.dk,
        martin.petersen@oracle.com, hch@lst.de
Subject: Re: [PATCH] block: reintroduce discard_zeroes_data sysfs file and
        BLKDISCARDZEROES
Message-ID: <20170816151803.GB18932@lst.de>
References: <1502889581-19483-1-git-send-email-lczerner@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1502889581-19483-1-git-send-email-lczerner@redhat.com>
Sender: linux-fsdevel-owner@vger.kernel.org
List-ID: <linux-fsdevel.vger.kernel.org>

The patch is incorrect - just because we support zeroing using
write zero doesn't mean that any discard will zero the data.

This subtle difference was one of the main point for the changes.