From: Andrew Morton Subject: Re: [PATCH 2/2] ext2: Avoid rec_len overflow with 64KB block size Date: Thu, 18 Oct 2007 02:11:55 -0700 Message-ID: <20071018021155.0b648616.akpm@linux-foundation.org> References: <20070828190551.415127746@sgi.com> <20070828190735.292638294@sgi.com> <1188432669.3799.35.camel@localhost.localdomain> <1188434857.3799.76.camel@localhost.localdomain> <1191285346.11737.58.camel@localhost.localdomain> <20071004131207.65406a7b.akpm@linux-foundation.org> <20071011111849.GC7125@duck.suse.cz> <20071017210925.c3c66de5.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Jan Kara , cmm@us.ibm.com, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, sho@tnes.nec.co.jp To: Christoph Lameter Return-path: Received: from smtp2.linux-foundation.org ([207.189.120.14]:36434 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755869AbXJRJMM (ORCPT ); Thu, 18 Oct 2007 05:12:12 -0400 In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Thu, 18 Oct 2007 02:03:39 -0700 (PDT) Christoph Lameter wrote: > On Wed, 17 Oct 2007, Andrew Morton wrote: > > > b) what happens when an old ext2 driver tries to read and/or write this > > directory entry? Do we need a compat flag for it? > > Old ext2 only supports up to 4k > > include/linux/ext2_fs.h: > > #define EXT2_MIN_BLOCK_SIZE 1024 > #define EXT2_MAX_BLOCK_SIZE 4096 > #define EXT2_MIN_BLOCK_LOG_SIZE 10 > > Should fail to mount the volume since the block size is too large. should, but does it? box:/usr/src/25> grep MAX_BLOCK_SIZE fs/ext2/*.[ch] include/linux/ext2* include/linux/ext2_fs.h:#define EXT2_MAX_BLOCK_SIZE 4096 box:/usr/src/25>