Re: [mdadm PATCH] Create: move STOP_ARRAY to abort_locked

[Jes Sorensen <jes.sorensen@gmail.com>]

On 05/07/2017 09:50 PM, Zhilong Liu wrote:
>
>
> On 05/05/2017 11:31 AM, Liu Zhilong wrote:
>>
>>
>> On 05/04/2017 10:54 PM, Jes Sorensen wrote:
>>> On 05/04/2017 08:20 AM, Zhilong Liu wrote:
>>>> Hi Jes,
>>>>
>>>> apply for review, this is a bug I ever encountered.
>>>
>>> Zhilong,
>>>
>>> Under what circumstances do you see this?
>>>
>>
>> Issued the command:
>> linux-g0sr:/home/test # ./mdadm -CR /dev/md0 -l1 -n2 -b internal
>> /dev/loop[0-1] --size 63
>> ... ... ...
>> mdadm: Given bitmap chunk size not supported.
>> linux-g0sr:/home/test # ls /dev/md0
>> /dev/md0
>> linux-g0sr:/home/test # ls /sys/block/md0/md/
>> array_size   bitmap      component_size  level metadata_version
>> raid_disks         reshape_position safe_mode_delay
>> array_state  chunk_size  layout          max_read_errors
>> new_dev           reshape_direction  resync_start
>>
>> create_mddev() writes the devnm to
>> /sys/module/md_mod/parameter/new_array,
>> then in md.c, module_param_call() called the 'set' function of
>> add_named_array(),
>> md_alloc() init_and_add the kobject for devm, finally the devnm device
>> has created
>> and sysfs has registered after create_mddev executed successfully.
>> Thus it's better
>> to STOP_ARRAY in any case after create_mddev() invoked.
>>
>
> this patch depends on the kernel commit:
> 039b7225e6e9 ("md: allow creation of mdNNN arrays via
> md_mod/parameters/new_array")
> Neil's patch has set "mddev->hold_active = UNTIL_STOP", thus the
> STOP_ARRAY can work
> well on this situation.

OK now I am confused - are you saying this change will only work after 
Neil's kernel patch has been applied? That would be no good, mdadm needs 
to work on older kernels too.

Jes