From: Eric Sandeen Subject: Re: should ext2fs_get_device_size() be returning EFBIG for >8T (or 16T?) Date: Tue, 23 Oct 2007 13:48:08 -0500 Message-ID: <471E41E8.2020306@redhat.com> References: <471E40CA.2070500@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 ([66.187.233.31]:39417 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752490AbXJWSsL (ORCPT ); Tue, 23 Oct 2007 14:48:11 -0400 Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by mx1.redhat.com (8.13.8/8.13.1) with ESMTP id l9NImArU000919 for ; Tue, 23 Oct 2007 14:48:10 -0400 Received: from pobox-2.corp.redhat.com (pobox-2.corp.redhat.com [10.11.255.15]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id l9NImAcp006274 for ; Tue, 23 Oct 2007 14:48:10 -0400 Received: from liberator.sandeen.net (sebastian-int.corp.redhat.com [172.16.52.221]) by pobox-2.corp.redhat.com (8.13.1/8.13.1) with ESMTP id l9NIm9cw009623 for ; Tue, 23 Oct 2007 14:48:09 -0400 In-Reply-To: <471E40CA.2070500@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Eric Sandeen wrote: > I have a bug saying hey, I can't grow my filesystem on a 16T device, and > it's because really we can only go to (2^32)-1 blocks, not (2^32)... > > I was going to just silently round down by a block, because for example > LVM makes it *very* easy to make exactly 16T devices; dropping a block > at mkfs/growfs time seems reasonable to me. > > So that led me to ext2fs_get_device_size, and I see it actually has the > maximum allowable filesystem size encoded in it, and you get EFBIG if > it's bigger. Actually I guess it's looking at the largest number a blk_t can hold, but I think the same principle applies. Maybe it's not a big deal today... -Eric