Re: [PATCH blktests] zbd/005: Limit block size to zone length

["hch@infradead.org" <hch@infradead.org>]

On Fri, Apr 25, 2025 at 12:04:39AM -0400, Sean Anderson wrote:
> and in userspace that assumes 512-byte granularity. But there is no
> such deeply-ingrained assumption for zones. You just have to set the
> parameter correctly.

There are everywhere in software actually using zones.  You still
haven't answered whay your intended use case is, btw.

> Plus, smaller zones are more efficient at reducing write amplification,
> in the same way as smaller block sizes.

No, they aren't.  If you zones are only a few kb you will waste a lot
of effort to actually track their state.

> If you really think such zone sizes should not be supported, then go
> add such a restriction to all the zone standards.

The zoned standards are extremely lax in what they allow, that is by
intent.  Actually software supports a lot less, and that for a good
reason,

> > Yes, it would be nice to have a sanity check for that and reject it
> > early, but no one is going to rewrite tests to remove that "assumption".
> 
> This assumption is very weak. It can easily be removed.

It can, but it's a really bad idea.

We're running in circles.  You are doing something very silly with
something not support in the kernel right now, without a use case
and are lecturing people who've done zoned software for years with
made up falsehoods.  That's not going very well.  Maybe your clever
scheme actually is better than what everyone has done for years, but
you'd better explain it very well and show how it's actually going
to work.