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

[Coly Li <i@coly.li>]

On 22/11/2017 9:14 PM, Stefan Priebe - Profihost AG wrote:
> Am 22.11.2017 um 13:57 schrieb Coly Li:
>> On 22/11/2017 8:26 PM, Stefan Priebe - Profihost AG wrote:
>>>
>>> Am 22.11.2017 um 13:16 schrieb Coly Li:
>>>> On 22/11/2017 7:23 PM, Stefan Priebe - Profihost AG wrote:
>>>>> Hello,
>>>>>
>>>>> i've 6 bcache blk devices attached to 3 caching ssds (2 each). One fails
>>>>> to register automatically at boot time.
>>>>>
>>>>> After reboot i always need to execute:
>>>>> echo /dev/sdf1 >/sys/fs/bcache/register
>>>>>
>>>>> to bring up the bcache device.
>>>>>
>>>>> Any idea?
>>>>
>>>> Hi Stefan,
>>>>
>>>> Is there any clue from kernel message ?
>>>
>>> Sadly not.
>>>
>>> Working one:
>>> ]# dmesg | grep sdi
>>> [    1.060377] sd 5:0:0:0: [sdi] 1953525168 512-byte logical blocks:
>>> (1.00 TB/932 GiB)
>>> [    1.060393] sd 5:0:0:0: [sdi] Write Protect is off
>>> [    1.060396] sd 5:0:0:0: [sdi] Mode Sense: 00 3a 00 00
>>> [    1.060425] sd 5:0:0:0: [sdi] Write cache: enabled, read cache:
>>> enabled, doesn't support DPO or FUA
>>> [    1.104341]  sdi: sdi1
>>> [    1.104644] sd 5:0:0:0: [sdi] Attached SCSI disk
>>> [    2.005452] bcache: register_bdev() registered backing device sdi1
>>> [    2.045211] bcache: bch_cached_dev_attach() Caching sdi1 as bcache0
>>> on set 76b95bf8-9cc7-407f-9f9e-a42b6d1bcb27
>>>
>>>
>>> not working one:
>>> # dmesg | grep sdf
>>> [    0.946107] sd 0:0:5:0: [sdf] 1953525168 512-byte logical blocks:
>>> (1.00 TB/932 GiB)
>>> [    1.400267] sd 0:0:5:0: [sdf] Write Protect is off
>>> [    1.400267] sd 0:0:5:0: [sdf] Mode Sense: 00 00 00 00
>>> [    1.401347] sd 0:0:5:0: [sdf] Write cache: enabled, read cache:
>>> enabled, supports DPO and FUA
>>> [    1.902910]  sdf: sdf1
>>> [    2.341289] sd 0:0:5:0: [sdf] Attached SCSI disk
>>> [  295.458804] bcache: register_bdev() registered backing device sdf1
>>> [  295.506656] bcache: bch_cached_dev_attach() Caching sdf1 as bcache5
>>> on set 76b95bf8-9cc7-407f-9f9e-a42b6d1bcb27
>>>
>>> At 295s i registeeed it manually.
>>
>> 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.

Hi Stefan,

Can you download the patch from following URL:
https://git.kernel.org/pub/scm/linux/kernel/git/colyli/bcache-patches.git/plain/for-test/0001-bcache-fix-a-circular-dead-locking-with-dc-writeback.patch

Coly Li