From: Christoph Lameter <clameter@sgi.com>
Subject: Re: [PATCH 2/2] ext2: Avoid rec_len overflow with 64KB block size
Date: Thu, 18 Oct 2007 02:03:39 -0700 (PDT)
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To: Andrew Morton <akpm@linux-foundation.org>
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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.