From mboxrd@z Thu Jan 1 00:00:00 1970 From: jim owens Subject: Re: [PATCH 0/4] Fiemap, an extent mapping ioctl - round 2 Date: Thu, 03 Jul 2008 08:11:38 -0400 Message-ID: <486CC1FA.10003@hp.com> References: <20080625221835.GQ28100@wotan.suse.de> <1214489061.6237.16.camel@norville.austin.ibm.com> <4863A483.5060303@redhat.com> <1214490465.6237.24.camel@norville.austin.ibm.com> <486C13B7.4030402@hp.com> <20080703111726.GZ29319@disturbed> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-fsdevel@vger.kernel.org To: Dave Chinner Return-path: Received: from g4t0014.houston.hp.com ([15.201.24.17]:29613 "EHLO g4t0014.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751849AbYGCMLq (ORCPT ); Thu, 3 Jul 2008 08:11:46 -0400 In-Reply-To: <20080703111726.GZ29319@disturbed> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Dave Chinner wrote: > xfs_bmap provides an atomic sync and mapping. If the > FIEMAP_FLAG_SYNC is pushed down to the filesystem, then XFS > and all other filesystems can provide that same atomicity if > desired. That is exactly what I was afraid of. We are back to the "because XFS has it" argument. But many other filesystems won't be able to provide atomicity without normal operation performance being reduced. And I say we don't want fiemap to hurt normal operation so fiemap should not impose even an implied need for atomicity because programmers will expect it and code for it. If XFS users want atomic SYNC, they can use xfs_bmap, or if XFS wants, it can always sync in its fiemap. jim