b.caches = make(map[string]metacache, 10)
	b.cachesRoot = make(map[string][]string, 10)
}

// deleteCache will delete a specific cache and all files related to it across the cluster.
func (b *bucketMetacache) deleteCache(id string) {
	b.mu.Lock()
	c, ok := b.caches[id]
	if ok {
		// Delete from root map.
		list := b.cachesRoot[c.root]
		for i, lid := range list {