Re: [PATCH] ext2/3 as ext4

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Hi Ted,

On Mon, Dec 07, 2009 at 02:09:47PM -0500, tytso@mit.edu wrote:
> On Tue, Dec 01, 2009 at 08:30:36PM -0500, Philip Wernersbach wrote:
> > Hello Everyone,
> >      Below is a small patch I wrote for kernel version 2.6.31.6. It
> > causes ext2/3 filesystems to be mounted using the ext4 driver, in a
> > way that is transparent to the userspace (and kernelspace for that
> > matter, as long as the code uses the kernel's mounting API) and
> > requires no change to the userspace (/kernelspace). This patch is
> > useful because: 1) It allows minimalist kernel fanatics, like myself,
> > to drop 2 drivers from their builds without any loss in functionality.
> > 2) It allows the ext2/3 filesystems to take advantage of the
> > performance/general improvements in the ext4 driver. 3) In the future,
> > with this patch, the ext2/3 driver code could be dropped from the
> > kernel without any loss in functionality.
> 
> Here's a much cleaner patch which achieves the same goal...
> 

I experience regular crashes with 2.6.32-rc2 that seem to be related to
this patch as thet seem to go away if I enable proper ext3 support.

Kernel BUG()s out in ext4_da_update_reserve_space(); unofrtunately
traces don't make it ot the disk but I managed to snatch a picture with
my didgital camera:

	http://userweb.kernel.org/~dtor/ext4-oops.jpg

I also tried pulling your latest pull request for Linus but the behavior
is the same.

Thanks.

-- 
Dmitry