Such driver exists already, http://www.fs-driver.org/ and it's fully IFS.

2009/11/11 Love Nystrom <love.nystrom@gmail.com>
 
If not, the IFS driver can not implement the full NT security model 
(neither can FAT), but I think it would still be a good idea to have
an ext2/ext3 IFS driver. Even better if we could support
a journaling fs like f.ex reiserfs.

Best Regards // Love