From mboxrd@z Thu Jan  1 00:00:00 1970
From: Kent Overstreet <kmo@daterainc.com>
Subject: Re: 3.18.1 + latest bcache-dev
Date: Sat, 3 Jan 2015 16:46:21 -0800
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To: Rolf Fokkens <rolf@rolffokkens.nl>
Cc: Slava Pestov <sp@datera.io>, "Stephen R. van den Berg" <srb@cuci.nl>, linux-bcache@vger.kernel.org

On Sat, Jan 03, 2015 at 05:40:24PM +0100, Rolf Fokkens wrote:
> Hi Slava,
> 
> Sounds like the kernel (using bcache-dev) is not able to handle the current
> format. If so, bcache-tools may help in "reformatting" bcache devices, but
> that's no solution for existing systems.
> 
> So is my understanding correct that there's no easy kernel upgrade path (to
> bcache-dev) ?

Yes, correct. The on disk format changes in bcache-dev are just too deep to
feasibly write backwards compat code, unfortunately.

And the on disk format is still in flux - for just a bit longer hopefully
though, right now I'm working on a pretty major revamp that's getting close to
done (self describing and packed metadata). This revamp is making the on disk
format _much_ more flexible though, and cleaning up a lot of stuff at the same
time.