Re: [PATCH 0/3] Bcache: version 4

[Kent Overstreet <kent.overstreet@gmail.com>]

On 05/01/2010 05:01 AM, Valdis.Kletnieks@vt.edu wrote:
> On Fri, 30 Apr 2010 16:12:13 -0800, Kent Overstreet said:
>
>> Most of the basic functionality is now there; the most visible thing is
>> it's now correctly saving all the metadata, so you can unload a cache
>> and then reload it, and everything will still be there.
>
> If you unload a cache and then reload it, what prevents it from serving
> up now-stale data from an extent that was modified while the cache was
> unloaded?
>
> (Telling me "Get some caffeine, it's about halfway down in patch 2" or
> "We'll add that in Version 6 of the patch" are both acceptable answers" :)

The plan is check if any devices are open read write on cache load and 
unload, and invalidate their cached data if so. Not implemented yet, though.