From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755611Ab1BNPDQ (ORCPT ); Mon, 14 Feb 2011 10:03:16 -0500 Received: from rcsinet10.oracle.com ([148.87.113.121]:42358 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753940Ab1BNPDP (ORCPT ); Mon, 14 Feb 2011 10:03:15 -0500 Content-Type: text/plain; charset=UTF-8 From: Chris Mason To: Josef Bacik Cc: Marti Raudsepp , btrfs hackers , Kernel hackers Subject: Re: btrfs: compression breaks cp and cross-FS mv, FS_IOC_FIEMAP bug? In-reply-to: <20110213161329.GL19533@dhcp231-156.rdu.redhat.com> References: <20110213155730.GK19533@dhcp231-156.rdu.redhat.com> <20110213161329.GL19533@dhcp231-156.rdu.redhat.com> Date: Mon, 14 Feb 2011 10:01:47 -0500 Message-Id: <1297695521-sup-9460@think> User-Agent: Sup/git Content-Transfer-Encoding: 8bit X-Source-IP: acsmt353.oracle.com [141.146.40.153] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090201.4D59441C.002E:SCFMA4539814,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Excerpts from Josef Bacik's message of 2011-02-13 11:13:30 -0500: > On Sun, Feb 13, 2011 at 06:07:36PM +0200, Marti Raudsepp wrote: > > On Sun, Feb 13, 2011 at 17:57, Josef Bacik wrote: > > > Does the same problem happen when you use cp --sparse=never? > > > > You are right. cp --sparse=never does not cause data loss. > > > > So fiemap probably isn't doing the right thing when compression is enabled, > which doesn't suprise me since we don't do the right thing with delalloc either. > I will try and get to this soon. Thanks, This might be a bug in the cp code. We're setting the disk extent to zero but setting different flags to say we're inline and compressed. The cp fiemap code might be ignoring the flags? Or, it could just be delalloc ;) -chris