// gcTreeStore removes all treeStoreIDs not referenced by any non garbage
// collected pod from the store.
func gcTreeStore(s *store.Store) error {
// Take an exclusive lock to block other pods being created.
// This is needed to avoid races between the below steps (getting the
// list of referenced treeStoreIDs, getting the list of treeStoreIDs
// from the store, removal of unreferenced treeStoreIDs) and new
// pods/treeStores being created/referenced
keyLock, err := lock.ExclusiveKeyLock(lockDir(), common.PrepareLock)
if err != nil {
return fmt.Errorf("cannot get exclusive prepare lock: %v", err)
}
defer keyLock.Close()
referencedTreeStoreIDs, err := getReferencedTreeStoreIDs()
if err != nil {
return fmt.Errorf("cannot get referenced treestoreIDs: %v", err)
}
treeStoreIDs, err := s.GetTreeStoreIDs()
if err != nil {
return fmt.Errorf("cannot get treestoreIDs from the store: %v", err)
}
for _, treeStoreID := range treeStoreIDs {
if _, ok := referencedTreeStoreIDs[treeStoreID]; !ok {
if err := s.RemoveTreeStore(treeStoreID); err != nil {
stderr("rkt: error removing treestore %q: %v", treeStoreID, err)
} else {
stderr("rkt: removed treestore %q", treeStoreID)
}
}
}
return nil
}