Re: Suggestion needed for fixing RAID6

[MRK <mrk@shiftmail.org>]

On 04/28/2010 03:37 AM, Neil Brown wrote:
>> --- linux-2.6.33-vanilla/drivers/md/raid5.c     2010-02-24
>> 19:52:17.000000000 +0100
>> +++ linux-2.6.33/drivers/md/raid5.c     2010-04-27 23:58:31.000000000 +0200
>> @@ -1526,7 +1526,7 @@ static void raid5_end_read_request(struc
>>
>>                   clear_bit(R5_UPTODATE,&sh->dev[i].flags);
>>                   atomic_inc(&rdev->read_errors);
>> -               if (conf->mddev->degraded)
>> +               if (conf->mddev->degraded == conf->max_degraded)
>>                           printk_rl(KERN_WARNING
>>                                     "raid5:%s: read error not correctable "
>>                                     "(sector %llu on %s).\n",
>>
>> ------------------------------------------------------
>> (This is just compile-tested so try at your risk)
>>
>> I'd like to hear what Neil thinks of this...
>>      
> I think you've found a real bug - thanks.
>
> It would make the test '>=' rather than '==' as that is safer, otherwise I
> agree.
>
>    
>> -               if (conf->mddev->degraded)
>> +               if (conf->mddev->degraded>= conf->max_degraded)
>>      

Right, agreed...

> Thanks,
> NeilBrown
>    

Ok then I'll post a more official patch in a separate email shortly, thanks