From: Girish Shilamkar Subject: [RFC] EXT_MAX_BLOCK for >= 16TB fs Date: Mon, 07 Jul 2008 22:25:32 +0530 Message-ID: <1215449732.1167.11.camel@alpha.linsyssoft.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7BIT Cc: adilger@Sun.COM, Theodore Tso To: Ext4 Mailing List Return-path: Received: from sineb-mail-2.sun.com ([192.18.19.7]:33616 "EHLO sineb-mail-2.sun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753445AbYGGRaM (ORCPT ); Mon, 7 Jul 2008 13:30:12 -0400 Received: from fe-apac-05.sun.com (fe-apac-05.sun.com [192.18.19.176] (may be forged)) by sineb-mail-2.sun.com (8.13.6+Sun/8.12.9) with ESMTP id m67HV8iB002645 for ; Mon, 7 Jul 2008 17:31:12 GMT Received: from conversion-daemon.mail-apac.sun.com by mail-apac.sun.com (Sun Java System Messaging Server 6.2-6.01 (built Apr 3 2006)) id <0K3N00M01CJZMT00@mail-apac.sun.com> (original mail from Girish.Shilamkar@Sun.COM) for linux-ext4@vger.kernel.org; Tue, 08 Jul 2008 01:29:35 +0800 (SGT) Sender: linux-ext4-owner@vger.kernel.org List-ID: Hi, The magic constant EXT_MAX_BLOCK = 0xffffffff in extents code is used in some places to return "invalid block number", and to set the extent length = "whole file" in other places. So with >= 16 TB fs we would prefer to use it differently. We can have EXT_UNSET_BLOCK = 1 to indicate "invalid block number" as it will never be valid block for allocation. And for "whole file" usecase we can continue using current EXT_MAX_BLOCK Regards, Girish