Original mailing list thread:
http://lists.gnu.org/archive/html/grub-devel/2011-09/msg00031.html

On 2011-09-28, Vladimir 'φ-coder/phcoder' Serbinenko wrote:
> Could you please split this patch? In particular the removing of dprintf
> takes to much of this patch and makes it unreadable. Note that we don't
> comment out the code, we only remove it.

[I am not the original patch writer.]

I've edited the patch to get rid of the dprintf removals. I also fixed a
pile of whitespace discrepancies. The patch is much easier to read now.
This updated patch is attached. It applies cleanly to revision 3473.
Unfortunately, I'm not familiar enough with the GRUB codebase to merge
it with anything much newer.

According to the commit message in the URL above, there are 7
non-logging changes in this patch. Even knowing which of those, if any,
have already been addressed (or rendered moot) in trunk would be
extremely helpful, as it might bring the amount of work required to
within my grasp.

phcoder: Any chance you could take a look at this?

I think ashift=12 support is still missing in trunk. gentoofan on IRC
provided this (completely untested) patch to trunk:
http://paste.pocoo.org/show/535465/

pendor: Do you still have copies of the zpools that were triggering
these errors? Do they contain confidential data? How big are they?

Thanks,
Richard