Re: [PATCH] btt: fix block integrity

[Jeff Moyer <jmoyer@redhat.com>]

Dan Williams <dan.j.williams@intel.com> writes:

> Keith Busch wrote:
>> On Wed, Nov 13, 2024 at 01:03:58PM -0600, Ira Weiny wrote:
>> > Keith Busch wrote:
>> > > From: Keith Busch <kbusch@kernel.org>
>> > > 
>> > > bip is NULL before bio_integrity_prep().
>> > 
>> > Did this fail in some way the user might see?  How was this found?
>> 
>> I think this means no one ever used block integrity with btt. :)
>> 
>> I found this purely from code inspection because I was combing through
>> bio_integrity for a completely unrelated problem. I was trying to make
>> sense of how other drivers use it, and this one didn't make any.
>>  
>> > I think the code is correct but should this be backported to stable or
>> > anything?
>> 
>> Up to you! It's not fixing a regression since it appears to have never
>> worked before. You can also just delete support for it entirely if no
>> one cares to use this feature.
>
> I think most people are just hoping that filesystem metadata checksums
> are catching torn writes and not using btt. For the few that do not have
> a checksumming filesystem and are using btt I only expect they are using
> 512 or 4K sector sizes and not the sizes with integrity metadata. For
> the ones that are using the odd sizes with integrity metadata they
> obviously do not care about the integrity data being transferred since
> that never apparently worked.
>
> My vote is delete the integrity support, but keep the odd sector size
> support for compatibility.

More generally, does anyone use btt?  Should we start the deprecation
process for it?

-Jeff