Re: ont out of 6 bcache devices does not register automatically

[Stefan Priebe - Profihost AG <s.priebe@profihost.ag>]

Hi Coly,
  Hi Michael,


Am 22.11.2017 um 20:06 schrieb Stefan Priebe - Profihost AG:
> Am 22.11.2017 um 18:51 schrieb Michael Lyle:
>> Hi Coly, Stefan--
>>
>> On 11/22/2017 05:14 AM, Stefan Priebe - Profihost AG wrote:
>>>> Hi Stefan,
>>>>
>>>> Hmm, I don't have idea here. Anyway, is the cache mode set as writeback?
>>>> Recently I post a patch to fix a potential deadlock between writeback
>>>> rate update kworker and register code, I am not sure whether it is
>>>> relative to your issue, but at least we can have a try. the patch title is:
>>>>  [RFC] bcache: fix a circular dead locking with dc->writeback_lock and
>>>> bch_register_lock
>>>>
>>>> Just for your information.
>>>
>>> i can try that one - can you please resend? I can't find that mail and
>>> don't know how to grab that one our of the web html archives to apply
>>> correctly.
>>>
>>> Stefan
>>
>> I don't think there's any chance this patch will do anything.  If
>> there's a deadlock, the whole thing will become stuck forever and never
>> allow registration or progress on the device again-- which doesn't match
>> the symptoms here.
> 
> No it does not ;-)
> 
>> This probably relates to udev configuration in your environment somehow.

I found the problem the device is not detected as bcache by blkid - see
here:

'/sbin/blkid -o udev -p /dev/sdf1'(out) 'ID_FS_AMBIVALENT=other:bcache
other:xfs_external_log'

normally it looks like this:
'/sbin/blkid -o udev -p /dev/sdg1'(out) 'ID_FS_TYPE=bcache'

so instead of setting the FS_TYPE to bcache it's ID_FS_AMBIVALENT which
skips the bcache udev rules.

Just no idea how to fix that.

Stefan