// gcTreeStore removes all treeStoreIDs not referenced by any non garbage // collected pod from the store. func gcTreeStore(ts *treestore.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 errwrap.Wrap(errors.New("cannot get exclusive prepare lock"), err) } defer keyLock.Close() referencedTreeStoreIDs, err := getReferencedTreeStoreIDs() if err != nil { return errwrap.Wrap(errors.New("cannot get referenced treestoreIDs"), err) } treeStoreIDs, err := ts.GetIDs() if err != nil { return errwrap.Wrap(errors.New("cannot get treestoreIDs from the store"), err) } for _, treeStoreID := range treeStoreIDs { if _, ok := referencedTreeStoreIDs[treeStoreID]; !ok { if err := ts.Remove(treeStoreID); err != nil { stderr.PrintE(fmt.Sprintf("error removing treestore %q", treeStoreID), err) } else { stderr.Printf("removed treestore %q", treeStoreID) } } } return nil }