Re: bcache fails after reboot if discard is enabled

[Michael Goertz <goertzm@gmail.com>]

Stefan Priebe <s.priebe <at> profihost.ag> writes:

> 
> Hi Rolf,
> Am 03.01.2015 um 17:32 schrieb Rolf Fokkens:
> > I've been using discard for a while, but I ran a few times in serious FS
> > corruptions. After disabling discard bcache was stable again.
> >
> > So far I tributed the corruptions to a low-cost SSD which probably
> > didn't handle discard very well. But this was only an assumptions.
> >
> > I didn't experience specific reboot problems like you describe.
> 
> Reboot just triggers it faster and even fs crashes can occur the errors 
> are just examples.
> 
> I've now disabled discards in my kernel code.
> 
> Kent may you have a look at the 3.18 kernel code regading discards?
> 
> Greets,
> Stefan
> 

I just started using bcache and run into this same issue after a reboot.  I 
was running in writeback mode at the time and run into some FS loss as a 
result.  I don't have back traces since my machine wouldn't boot.  I 
recovered by removing the cache device and forcing the backing device to run 
without it.

I am running Ubuntu 14.04 with the Utopic kernel.  I can provide more 
details of my setup and hardware if that's helpful.

Thanks,
Mike