[dm-devel] Bcache upstreaming

[Mike Snitzer]

(take3 with feeling.. I reverted to the gmail's old compose so all
should be right in my plain-text gmail world... apologies to Kent and
dm-devel for the redundant messages)

Hey Kent,

On Fri, Jan 4, 2013 at 6:50 PM, Kent Overstreet <koverstreet at google.com> wrote:
> I've (finally!) got a bcache branch hacked up that ought to be suitable
> to go upstream, possibly in staging initially.
>
> It's currently closer to the dev branch than the stable branch, plus
> some additional minor changes to make it all more self contained. The
> code has seen a decent amount of testing and I think it's in good shape,
> but I'd like it if it could see a bit more testing before I see about
> pushing it upstream.
>
> If anyone wants to try it out, checkout the bcache-for-staging branch.
> It's against Linux 3.7.

I pulled your 'bcache-for-staging' code into a 'dm-devel-cache-bcache'
branch on my github:
https://github.com/snitm/linux

Purpose is to have a single kernel to compare dm-cache and bcache.  My
branch is against 3.8-rc2.  While importing your code I needed the
following change to get bcache to compile:
https://github.com/snitm/linux/commit/400b1257e93975864fd6c4b827537a0234551253

It now builds without issue but I haven't tested the resulting bcache
to know if I broke the sysfs interface due to s/cache/bcache/ on some
local variables, I don't think I did but I'll defer to you.  (BTW
those crafty sysfs macros you have were pretty opaque; not really
seeing what they buy in the grand scheme.  And #include "sysfs.c" is
different than any code I've seen in the kernel).