From: "Aneesh Kumar K.V" Subject: When to set EXT4_FEATURE_RO_COMPAT_LARGE_FILE ? Date: Thu, 11 Oct 2007 22:34:13 +0530 Message-ID: <470E578D.4040308@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit To: linux-ext4 , Theodore Tso , Andreas Dilger , Mingming Cao Return-path: Received: from E23SMTP03.au.ibm.com ([202.81.18.172]:52858 "EHLO e23smtp03.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753400AbXJKREq (ORCPT ); Thu, 11 Oct 2007 13:04:46 -0400 Received: from sd0109e.au.ibm.com (d23rh905.au.ibm.com [202.81.18.225]) by e23smtp03.au.ibm.com (8.13.1/8.13.1) with ESMTP id l9BH4fiv032269 for ; Fri, 12 Oct 2007 03:04:41 +1000 Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by sd0109e.au.ibm.com (8.13.8/8.13.8/NCO v8.5) with ESMTP id l9BH8F0I197076 for ; Fri, 12 Oct 2007 03:08:15 +1000 Received: from d23av04.au.ibm.com (loopback [127.0.0.1]) by d23av04.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l9BH4OJA026318 for ; Fri, 12 Oct 2007 03:04:25 +1000 Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Right now we do this in ext4_do_update_inode if (ei->i_disksize > 0x7fffffffULL) { ..... ..... EXT4_SET_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_LARGE_FILE); That is if i_disksize is greater that 2**31 -1 we set the flag But in ext4_inode the size of i_size is 32 bits __le32 i_size; /* Size in bytes */ That means it should be able to store ffffffffULL. Why did we decided to enable the EXT4_FEATURE_RO_COMPAT_LARGE_FILE when we cross 2**31 -1 ? NOTE: With EXT4_FEATURE_RO_COMPAT_LARGE_FILE we store the higer order 32 bits of i_size in i_dir_acl. -aneesh