Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754955Ab1B1PSB (ORCPT ); Mon, 28 Feb 2011 10:18:01 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36776 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754934Ab1B1PSA (ORCPT ); Mon, 28 Feb 2011 10:18:00 -0500 Message-ID: <4D6BBCA2.8030104@redhat.com> Date: Mon, 28 Feb 2011 09:17:54 -0600 From: Eric Sandeen User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.13) Gecko/20101207 Thunderbird/3.1.7 MIME-Version: 1.0 To: Dave Young CC: Josef Bacik , Theodore Tso , linux-ext4@vger.kernel.org, Linux Kernel Mailing List Subject: Re: ext2/3/4: punch support? References: <20110228131118.GA18193@dhcp231-156.rdu.redhat.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1605 Lines: 42 On 2/28/11 8:29 AM, Dave Young wrote: > On Mon, Feb 28, 2011 at 9:11 PM, Josef Bacik wrote: >> On Mon, Feb 28, 2011 at 03:03:40PM +0800, Dave Young wrote: >>> Hi, josef and ext guys >>> >>> Do you have any plan with ext4 hole punching support? And the >>> fallocate for ext2/3? >>> >>> What's the obstacle to work on this? could someone tell the status of >>> this issue? >> >> There is no obstacle, just nobody has bothered to do it. If you want to do it >> go for it. Thanks, > > Yes, I want to do some kvm image space discard stuff, > I use ext4 as my filesystem, but currently only xfs support something > like trim/discard. As Lukas said, ext4 & ext3 support various forms of trim/discard already. But that's different from punch... And as for fallocate on ext3, you need somewhere to put the metadata to indicate a block is allocated but not written. This was a lot more straightforward for ext4, since it describes a large range of blocks with a single extent structure. -Eric > I know general knowledge about ext filesystem, but nearly new to ext4 code, > could you give some hint where to start? > > -- > Thanks > dave > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/