[dm-devel] [PATCH for-3.14] dm cache: add total cache blocks to status output

[Joe Thornber]

On Thu, Jan 09, 2014 at 04:04:12PM -0500, Mike Snitzer wrote:
> Improve cache_status to emit <#used cache blocks>/<#total cache blocks>
> This provides useful context for the how much of the cache is used.

I'd be happy with this if cache wasn't already upstream.  But it is,
and this patch changes a kernel interface.  If you're going to do this
you need to:

i) bump the version number of the target module
ii) update the test suite
iii) apologise to users who's scripts are about to be broken.

<#used cache blocks> is already emitted.  The blocksize is available
from the table.  The <#total cache blocks> is just the SSD size
divided by the blocksize.  I see no compelling reason to make this
change.

- Joe