[Libguestfs] [PATCH v2 nbdkit 9/9] cache: Implement cache-max-size and method of reclaiming space from the cache.

This is version 2 of patch 9/9. Patches 1 through 8 didn't change so I didn't repost them. v2: - Implement a proper test. This turned out to be quite a lot more complicated than anticipated. - Fix the call to fallocate. It turns out that fallocate hole punching silently does nothing unless you use ‘FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE’. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://people.redhat.com/~rjones/virt-top