Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758889AbYAaPe4 (ORCPT ); Thu, 31 Jan 2008 10:34:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754878AbYAaPer (ORCPT ); Thu, 31 Jan 2008 10:34:47 -0500 Received: from smtprelay06.ispgateway.de ([80.67.18.44]:34513 "EHLO smtprelay06.ispgateway.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755959AbYAaPeq (ORCPT ); Thu, 31 Jan 2008 10:34:46 -0500 X-Greylist: delayed 375 seconds by postgrey-1.27 at vger.kernel.org; Thu, 31 Jan 2008 10:34:46 EST Date: Thu, 31 Jan 2008 16:28:23 +0100 From: Lars Noschinski To: linux-kernel@vger.kernel.org Subject: How does ext2 implement sparse files? Message-ID: <20080131152823.GA29422@lars.home.noschinski.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline User-Agent: mutt-ng/devel-r804 (Linux) X-Df-Sender: 336680 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 775 Lines: 21 Hello! For an university project, we had to write a toy filesystem (ext2-like), for which I would like to implement sparse file support. For this, I digged through the ext2 source code; but I could not find the point, where ext2 detects holes. As far as I can see from fs/buffer.c, an hole is a buffer_head which is not mapped, but uptodate. But I cannot find a relevant source line, where ext2 makes usage of this information. Any hints would be greatly appreciated, Lars. [Please CC me on answers, I'm not subscribed] -- 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/