Re: [libvirt] [PATCHv3 01/36] storage: backend: Add unique id retrieval API

Different protocols have different means to uniquely identify a storage file. This patch implements a storage driver API to retrieve a unique string describing a volume. The current implementation works for local storage only and returns the canonical path of the volume. To add caching support the local filesystem driver now has a private structure holding the cached string, which is created only when it's initially accessed. This patch provides the implementation for local files only for start. ---