Re: [PATCH 4/4] UBI: Implement bitrot checking (linux-mtd Digest, Vol 145, Issue 24)

[Richard Weinberger <richard@nod.at>]

Am 12.04.2015 um 23:30 schrieb Boris Brezillon:
> On Sun, 12 Apr 2015 23:01:27 +0200
> Richard Weinberger <richard@nod.at> wrote:
> 
> 
>>>>>>>> +static struct device_attribute dev_trigger_bitrot_check =
>>>>>>>> +    __ATTR(trigger_bitrot_check, S_IWUSR, NULL, trigger_bitrot_check);
>>>>>>>
>>>>>>> How about making this attribute a RW one, so that users could check
>>>>>>> if there's a bitrot check in progress.
>>>>>>
>>>>>> As the check will be initiated only by userspace and writing to the trigger
>>>>>> while a check is running will return anyway a EBUSY I don't really see
>>>>>> a point why userspace would check for it.
>>>>>
>>>>> Sometime you just want to know whether something is running or not (in
>>>>> this case the bitrot check) without risking to trigger a new action...
>>>>
>>>> Why would they care?
>>>
>>> I think is always useful to give some additional information in userspace, from both debugging and diagnostic point of view.
>>
>> The question is, why does userspace care?
>> Other UBI operations are also not visible...
> 
> Yes, but AFAIK other wear-leveling operations are not directly triggered
> by user-space.

If userspace trigger is, it knows that it was triggered.
Unless you have multiple tools/scripts which want to trigger it,
which is IMHO a problem anyways.

But as stated before, I can add an indicator.

Thanks,
//richard