Re: [RFC PATCH 0/2] dm crypt: Allow unaligned buffer lengths for skcipher devices

On Wed, 23 Sep 2020, Mike Snitzer wrote:

> You've clearly done a nice job with these changes.  Looks clean.
> 
> BUT, I'm struggling to just accept that dm-crypt needs to go to these
> extra lengths purely because of one bad apple usecase.
> 
> These alignment constraints aren't new.  Are there other portions of
> Linux's crypto subsystem that needed comparable fixes in order to work
> with Microsfot OS initiated IO through a guest?
> 
> You forecast that these same kinds of changes are needed for AEAD and
> dm-integrity... that's alarming.

... and dm-writecache also expects that the bio is aligned ...

Mikulas

> Are we _certain_ there is no other way forward?
> (Sorry I don't have suggestions.. I'm in "fact finding mode" ;)
> 
> Thanks,
> Mike