On Mon, 18 Dec 2023 08:11:53 -0800
Song Liu [off-list ref] wrote:

Hi Mariusz,

On Mon, Dec 18, 2023 at 12:32 AM Mariusz Tkaczyk
[off-list ref] wrote:

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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.
 

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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!

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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