From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga14.intel.com ([192.55.52.115]:58916 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934977AbcHEL5U (ORCPT ); Fri, 5 Aug 2016 07:57:20 -0400 Message-ID: <1470398236.2311.89.camel@gmail.com> Subject: Re: [PATCH v7 00/47] xfs: add reverse mapping support From: Artem Bityutskiy Reply-To: dedekind1@gmail.com To: Dave Chinner Cc: "Darrick J. Wong" , Mark Fasheh , linux-fsdevel@vger.kernel.org, vishal.l.verma@intel.com, bfoster@redhat.com, xfs@oss.sgi.com Date: Fri, 05 Aug 2016 14:57:16 +0300 In-Reply-To: <20160805104950.GF16044@dastard> References: <146907695530.25461.3225785294902719773.stgit@birch.djwong.org> <20160803194536.GJ5316@wotan.suse.de> <20160803205520.GQ8590@birch.djwong.org> <20160804005843.GJ8593@birch.djwong.org> <20160804021852.GK5316@wotan.suse.de> <20160804154845.GV8590@birch.djwong.org> <20160804235015.GC16044@dastard> <1470380474.2311.71.camel@gmail.com> <20160805104950.GF16044@dastard> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Fri, 2016-08-05 at 20:49 +1000, Dave Chinner wrote: > On Fri, Aug 05, 2016 at 10:01:14AM +0300, Artem Bityutskiy wrote: > > > > On Fri, 2016-08-05 at 09:50 +1000, Dave Chinner wrote: > > > > > > I'd much prefer that fiemap gives exact information about shared > > > extents. FIEMAP is a diagnostic tool and as such we need it to > > > accurately reflect the exact extent map of the inode being > > > queried > > > so we aren't mislead about the layout of the file during trouble > > > shooting. > > > > Hi Dave, you are right, and here is a side note:  we were using > > FIEMAP > > for optimizing image deployment in production, so it is a > > diagnostic > > tool and more. > > Yay, data corruption ahoy! > > Hasn't /anyone/ listened to the repeated statements from fs > developers that FIEMAP is not a safe method of optimising data > copying? Yes, which is kind of sad from the user's perspective. We had issues with XFS, not ext4, and tweaking preallocation helped.