// 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
}
func mountPodStage1(ts *treestore.Store, p *pkgPod.Pod) error {
if !p.UsesOverlay() {
return nil
}
s1Id, err := p.GetStage1TreeStoreID()
if err != nil {
return errwrap.Wrap(errors.New("error getting stage1 treeStoreID"), err)
}
s1rootfs := ts.GetRootFS(s1Id)
stage1Dir := common.Stage1RootfsPath(p.Path())
overlayDir := filepath.Join(p.Path(), "overlay")
imgDir := filepath.Join(overlayDir, s1Id)
upperDir := filepath.Join(imgDir, "upper")
workDir := filepath.Join(imgDir, "work")
opts := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s", s1rootfs, upperDir, workDir)
if err := syscall.Mount("overlay", stage1Dir, "overlay", 0, opts); err != nil {
return errwrap.Wrap(errors.New("error mounting stage1"), err)
}
return nil
}