From: Eric Sandeen Subject: "- 8" in EXT2_MAX_BLOCKS_PER_GROUP Date: Mon, 10 Oct 2011 10:50:43 -0500 Message-ID: <4E931453.3010002@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: ext4 development Return-path: Received: from mx1.redhat.com ([209.132.183.28]:21501 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750804Ab1JJPuq (ORCPT ); Mon, 10 Oct 2011 11:50:46 -0400 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p9AFojEm018858 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 10 Oct 2011 11:50:46 -0400 Received: from liberator.sandeen.net (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p9AFoiE4031094 (version=TLSv1/SSLv3 cipher=DHE-RSA-CAMELLIA256-SHA bits=256 verify=NO) for ; Mon, 10 Oct 2011 11:50:44 -0400 Sender: linux-ext4-owner@vger.kernel.org List-ID: When looking at the maximal filesystem size issue, I found myself wondering what the "- 8" is in here, it's not commented or documented anywhere: #define EXT2_MAX_BLOCKS_PER_GROUP(s) (((1 << 16) - 8) * \ (EXT2_CLUSTER_SIZE(s) / \ EXT2_BLOCK_SIZE(s))) (pre-bigalloc, it was just ((1 << 16) - 8) ) Anyone know? -Eric