From: Curt Wohlgemuth Subject: Re: Question on huge_file Date: Fri, 10 Jul 2009 09:31:20 -0700 Message-ID: <6601abe90907100931v40cf7b97h243642a469689ac5@mail.gmail.com> References: <6601abe90907100832q6ab886f2r7fc8e3be2a79e8e5@mail.gmail.com> <4A5760A7.60607@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: ext4 development To: Eric Sandeen Return-path: Received: from smtp-out.google.com ([216.239.33.17]:22523 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751474AbZGJQb0 convert rfc822-to-8bit (ORCPT ); Fri, 10 Jul 2009 12:31:26 -0400 Received: from wpaz21.hot.corp.google.com (wpaz21.hot.corp.google.com [172.24.198.85]) by smtp-out.google.com with ESMTP id n6AGVN7x000331 for ; Fri, 10 Jul 2009 17:31:23 +0100 Received: from wf-out-1314.google.com (wfg24.prod.google.com [10.142.7.24]) by wpaz21.hot.corp.google.com with ESMTP id n6AGVFto000737 for ; Fri, 10 Jul 2009 09:31:21 -0700 Received: by wf-out-1314.google.com with SMTP id 24so277450wfg.20 for ; Fri, 10 Jul 2009 09:31:20 -0700 (PDT) In-Reply-To: <4A5760A7.60607@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Hi Eric: On Fri, Jul 10, 2009 at 8:39 AM, Eric Sandeen wrote= : > Curt Wohlgemuth wrote: >> I apologize if this is a dumb question, but I'm having trouble >> understanding the huge_file superblock flag. >> >> I see how, if this flag is set, that the inode can have a size > 2**= 32 >> bytes, using the i_size_lo/i_size_high fields. >> >> But since an ext4_extent only uses 32-bits for for its ee_block fiel= d >> to represent the logical block, how can an extent describe any block >> range of a file past the 4GiB boundary? >> >> Am I missing something? > > i_size_lo/hi is in bytes, ee_block is in .... blocks. > > so 2^32 blocks is a lot more than 2^32 bytes, and i_size_hi/lo are > needed to contain it. =A0I think. =A0:) Oops. Of course. I knew it had to be something simple. Thanks, Curt -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html