Re: [PATCH 2/3] md-cluster: introduce clear_clusterinfo_from_sb

[Guoqing Jiang <gqJiang@suse.com>]

NeilBrown wrote:
> On Fri, Nov 27 2015, Guoqing Jiang wrote:
>
>   
>> Hi Neil,
>>
>> On 11/27/2015 01:42 PM, NeilBrown wrote:
>>     
>>> On Fri, Nov 20 2015, Guoqing Jiang <gqjiang@suse.com> wrote:
>>>
>>>       
>>>> To change the bitmap from clustered to none, we also
>>>> need to clean related info about cluster from sb, such
>>>> as version, nodes and cluster_name.
>>>>         
>>> I've applied the other two (though I removed the __func__ and __LINE__
>>>  From error messages - they are just noise: the source of the message can
>>> easily be found with out them - I should remove all the others).
>>>
>>> However I haven't applied this because there doesn't seem to be any
>>> point.
>>> Once your told that main md superblock that there is no bitmap, it
>>> doesn't really matter what data is in the superblock of that
>>> non-existent bitmap - it will never be looked at.  Will it?
>>>       
>> mdadm could still get nodes and cluster_name after change
>> bitmap to none, so some cmds like "mdadm -X /dev/sda" could
>> still see clustered info, it seems a little confused for user.
>>     
>
> In that case we should fix mdadm to not report a bitmap if
> MD_FEATURE_BITMAP_OFFSET isn't set (though maybe still report it if
> --force is given).
>
> i.e. if this is an issue, it is not specific to clustered-bitmaps.
>
>   
Thanks for the comment, I will modify mdadm for the case.

Regards,
Guoqing