Re: MDADM 3.3 broken?

[Martin Wilck <mwilck@arcor.de>]

On 11/19/2013 01:01 AM, NeilBrown wrote:
> On Mon, 18 Nov 2013 15:13:58 -0800 "David F." <df7729@gmail.com> wrote:
> 
> 
>> output of 'mdadm --assemble --scan --no-degraded -v' (mdadm 3.2.6):
> ...
>> mdadm: no RAID superblock on /dev/sdc2
> 
> 
> 
>>
>> output1 of 'mdadm --assemble --scan --no-degraded -v' (mdadm 3.3 -
>> note using /dev/sdc2, not /dev/sdc):
> .....
>> mdadm: /dev/sdc2 is identified as a member of /dev/md/imsm0, slot -1.
> 
> So there is the problem.  mdadm 3.2.6 sees no RAID superblock on sdc2, while
> mdadm 3.3 does (but should not).
> 
> 
> However that code hasn't changed!
> 
> load_super_imsm() still starts with:
> 
> 
> 	if (test_partition(fd))
> 		/* IMSM not allowed on partitions */
> 		return 1;

Well not quite - you changed that code in commit b31df436 "intel,ddf:
don't require partitions when ignore_hw_compat is set". Maybe there's
something wrong with that ignore_hw_compat logic?

In the strace I don't see indication of test_partition having been
called, that's another hint in that direction.

Martin

> 
> 
> and test_partition hasn't changed since it was written in April 2010 for
> mdadm 3.1.3.
> 
> So I'm quite perplexed.
> 
> Is your mdadm-3.3 compiled from source or provided by a distro?
> 
> Can you run the "mdadm --assemble" under strace and post the result?
> 
>   strace -o /tmp/some-file mdadm --assemble --scan ......
> 
> Thanks,
> NeilBrown