From: Wang Sheng-Hui Subject: Re: Question about extents.c/ext4_ext_punch_hole Date: Mon, 16 Jul 2012 16:04:54 +0800 Message-ID: <5003CB26.9040401@gmail.com> References: <5002BFAE.9030408@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Allison Henderson , Theodore Ts'o , linux-ext4@vger.kernel.org To: =?UTF-8?B?THVrw6HFoSBDemVybmVy?= Return-path: Received: from mail-ob0-f174.google.com ([209.85.214.174]:48514 "EHLO mail-ob0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750843Ab2GPIFI (ORCPT ); Mon, 16 Jul 2012 04:05:08 -0400 Received: by obbuo13 with SMTP id uo13so9153812obb.19 for ; Mon, 16 Jul 2012 01:05:08 -0700 (PDT) In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On 2012=E5=B9=B407=E6=9C=8816=E6=97=A5 14:36, Luk=C3=A1=C5=A1 Czerner w= rote: > Indeed we're going to align > the range to the block size, but that's because blocks in this range > are going to be freed. Then, the rest of the range (non block > aligned) is going to be zeroed manually. The reason is that we can > not free those blocks, because it still contains valid data and we > can not just leave it alone, since after the punch hole finishes > we'll have to read zeroes from entire punched region. >=20 Got it. Thanks, Lukas! -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html