bcache writeback hang with 3.11.5 and 3.10.17

bcache writeback hang with 3.11.5 and 3.10.17

[Pavel Palát]

Hello,

I have experienced hangs with above kernel and bcache in writeback mode. 
Hangs are very easily archieved - just do:

mkdir /data/tmp
cp -xar / /data/tmp

Cancel after 1-5 minutes, then do sync (sometimes don't needed) and it 
hangs. Either the sync hangs and/or the cp (or rm /data/tmp). Behaviour 
is very consistent, it happens every time I enable writeback and perform 
IO heavy operations.

I have not experienced the issue so far with writethrough mode.

Hardware is HP j000ec, attaching dmesg from hanged box with both 3.11.5 
and 3.10.17 LTS kernel. Distribution is arch linux.

dmesg outputs is available on 
http://www.devsoft.cz/upload/bcache_bugreport.tar.gz

P.

Re: bcache writeback hang with 3.11.5 and 3.10.17

[Pavel Palát]

On 20.10.2013 15:42, Pavel Palát wrote:
> Hello,
>
> I have experienced hangs with above kernel and bcache in writeback 
> mode. Hangs are very easily archieved - just do:
>
> mkdir /data/tmp
> cp -xar / /data/tmp
>
> Cancel after 1-5 minutes, then do sync (sometimes don't needed) and it 
> hangs. Either the sync hangs and/or the cp (or rm /data/tmp). 
> Behaviour is very consistent, it happens every time I enable writeback 
> and perform IO heavy operations.
>
> I have not experienced the issue so far with writethrough mode.
>
> Hardware is HP j000ec, attaching dmesg from hanged box with both 
> 3.11.5 and 3.10.17 LTS kernel. Distribution is arch linux.
>
> dmesg outputs is available on 
> http://www.devsoft.cz/upload/bcache_bugreport.tar.gz
>
> P.
Hello,

update: Tried with 3.12rc6 with same results. It also hangs with writeback.

http://www.devsoft.cz/upload/bcache_312.txt

Best regards,

Pavel Palat