Re: [PATCH 0/3] md: Remove deprecated flavors

[Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>]

On Mon, 18 Dec 2023 08:11:53 -0800
Song Liu <song@kernel.org> wrote:

> Hi Mariusz,
> 
> On Mon, Dec 18, 2023 at 12:32 AM Mariusz Tkaczyk
> <mariusz.tkaczyk@linux.intel.com> wrote:
> >  
> [...]
> > > >
> > > > Please note that there are mdadm tests for those levels. I can approve
> > > > it only when mdadm clean-up is merged. Our tests must pass
> > > > continuously.  
> > >
> > > Is the continuous test result available publicly?  
> >
> > We are working on public CI (Paul owns it). On my side I'm not executing all
> > tests, IMSM only. In this case it is obvious that mdadm tests will stop
> > passing, I don't need results to see that. We should keep both mdadm and md
> > compatible. We are continuously adding new MD regression tests to mdadm (at
> > least Kuai is doing that) so we should also care about removing things.
> >  
> > >  
> > > >
> > > > It is a nice code complexity improvement so let me know if you would
> > > > like to get my help with mdadm patches.  
> > >
> > > On my local tests with mdadm, I need to make changes to the following
> > > tests:
> > >
> > > 00linear...
> > > 00names...
> > > 00raid0...
> > > 00readonly...
> > > 02lineargrow...
> > > 03r0assem...
> > > 04r0update...
> > > 04update-metadata...
> > >
> > > The changes are all straightforward (just remove things related to
> > > linear/multipath/faulty).
> > >  
> >
> > Please do not forgot remove dead code from mdadm. For example simple find
> > "multipath" (case insensitive) reefers me to multiple places with special
> > handling for this level. We need to remove it from code and documentation.
> > Can you handle this too?  
> 
> I think this is a bigger discussion: will mdadm stop supporting these
> flavors on
> older kernels? Say, mdadm-5.0+ (or a different number) will not support
> multipath flavor on older kernels?
> 

Good point, I forgot that we are keeping backward compatibility with old
kernels. Currently 3.10 is the lowest one supported so agree, we need to keep
this code. Thanks for clarifying!

> >
> > Oh and last one, I can't find update for md man in your changes. Could you
> > please remove those levels from md man?  
> 
> man side is easier. Once we know which major will have this set (6.8 or
> later), we can update the man pages with the information.

Understood!

No further questions, please just remove tests and eventually add warning when
creating those levels in mdadm i.e "Linear/Multipath/Faulty are deprecated and
will be removed in next releases".

Thanks,
Mariusz