diff --git a/components/engine/graph.go b/components/engine/graph.go index 0c84dc4252..26b6a9c662 100644 --- a/components/engine/graph.go +++ b/components/engine/graph.go @@ -129,6 +129,9 @@ func (graph *Graph) Register(layerData Archive, img *Image) error { // Mktemp creates a temporary sub-directory inside the graph's filesystem. func (graph *Graph) Mktemp(id string) (string, error) { + if id == "" { + id = GenerateId() + } tmp, err := NewGraph(path.Join(graph.Root, ":tmp:")) if err != nil { return "", fmt.Errorf("Couldn't create temp: %s", err) @@ -139,13 +142,6 @@ func (graph *Graph) Mktemp(id string) (string, error) { return tmp.imageRoot(id), nil } -// Garbage returns the "garbage", a staging area for deleted images. -// This allows images to be deleted atomically by os.Rename(), instead of -// os.RemoveAll() which is prone to race conditions. -func (graph *Graph) Garbage() (*Graph, error) { - return NewGraph(path.Join(graph.Root, ":garbage:")) -} - // Check if given error is "not empty". // Note: this is the way golang does it internally with os.IsNotExists. func isNotEmpty(err error) bool { @@ -166,54 +162,16 @@ func (graph *Graph) Delete(name string) error { if err != nil { return err } - garbage, err := graph.Garbage() + tmp, err := graph.Mktemp("") if err != nil { return err } graph.idIndex.Delete(id) - err = os.Rename(graph.imageRoot(id), garbage.imageRoot(id)) - if err != nil { - // FIXME: this introduces a race condition in Delete() if the image is already present - // in garbage. Let's store at random names in grabage instead. - if isNotEmpty(err) { - Debugf("The image %s is already present in garbage. Removing it.", id) - if err = os.RemoveAll(garbage.imageRoot(id)); err != nil { - Debugf("Error while removing the image %s from garbage: %s\n", id, err) - return err - } - Debugf("Image %s removed from garbage", id) - if err = os.Rename(graph.imageRoot(id), garbage.imageRoot(id)); err != nil { - return err - } - Debugf("Image %s put in the garbage", id) - } else { - Debugf("Error putting the image %s to garbage: %s\n", id, err) - } - return err - } - return nil -} - -// Undelete moves an image back from the garbage to the main graph. -func (graph *Graph) Undelete(id string) error { - garbage, err := graph.Garbage() + err = os.Rename(graph.imageRoot(id), tmp) if err != nil { return err } - if err := os.Rename(garbage.imageRoot(id), graph.imageRoot(id)); err != nil { - return err - } - graph.idIndex.Add(id) - return nil -} - -// GarbageCollect definitely deletes all images moved to the garbage. -func (graph *Graph) GarbageCollect() error { - garbage, err := graph.Garbage() - if err != nil { - return err - } - return os.RemoveAll(garbage.Root) + return os.RemoveAll(tmp) } // Map returns a list of all images in the graph, addressable by ID.