diff --git a/layers.go b/layers.go index 34d27ffa33..bba8d7588f 100644 --- a/layers.go +++ b/layers.go @@ -692,11 +692,10 @@ func (r *layerStore) PutAdditionalLayer(id string, parentLayer *Layer, names []s return copyLayer(layer), nil } -func (r *layerStore) Put(id string, parentLayer *Layer, names []string, mountLabel string, options map[string]string, moreOptions *LayerOptions, writeable bool, flags map[string]interface{}, diff io.Reader) (layer *Layer, size int64, err error) { +func (r *layerStore) Put(id string, parentLayer *Layer, names []string, mountLabel string, options map[string]string, moreOptions *LayerOptions, writeable bool, flags map[string]interface{}, diff io.Reader) (*Layer, int64, error) { if !r.IsReadWrite() { return nil, -1, errors.Wrapf(ErrStoreIsReadOnly, "not allowed to create new layers at %q", r.layerspath()) } - size = -1 if err := os.MkdirAll(r.rundir, 0700); err != nil { return nil, -1, err } @@ -762,6 +761,60 @@ func (r *layerStore) Put(id string, parentLayer *Layer, names []string, mountLab if mountLabel != "" { label.ReserveLabel(mountLabel) } + + // Before actually creating the layer, make a persistent record of it with incompleteFlag, + // so that future processes have a chance to delete it. + layer := &Layer{ + ID: id, + Parent: parent, + Names: names, + MountLabel: mountLabel, + Metadata: templateMetadata, + Created: time.Now().UTC(), + CompressedDigest: templateCompressedDigest, + CompressedSize: templateCompressedSize, + UncompressedDigest: templateUncompressedDigest, + UncompressedSize: templateUncompressedSize, + CompressionType: templateCompressionType, + UIDs: templateUIDs, + GIDs: templateGIDs, + Flags: make(map[string]interface{}), + UIDMap: copyIDMap(moreOptions.UIDMap), + GIDMap: copyIDMap(moreOptions.GIDMap), + BigDataNames: []string{}, + } + r.layers = append(r.layers, layer) + r.idindex.Add(id) + r.byid[id] = layer + for _, name := range names { + r.byname[name] = layer + } + for flag, value := range flags { + layer.Flags[flag] = value + } + layer.Flags[incompleteFlag] = true + + succeeded := false + cleanupFailureContext := "" + defer func() { + if !succeeded { + // On any error, try both removing the driver's data as well + // as the in-memory layer record. + if err2 := r.Delete(layer.ID); err2 != nil { + if cleanupFailureContext == "" { + cleanupFailureContext = "unknown: cleanupFailureContext not set at the failure site" + } + logrus.Errorf("While recovering from a failure (%s), error deleting layer %#v: %v", cleanupFailureContext, layer.ID, err2) + } + } + }() + + err := r.Save() + if err != nil { + cleanupFailureContext = "saving incomplete layer metadata" + return nil, -1, err + } + idMappings := idtools.NewIDMappingsFromMaps(moreOptions.UIDMap, moreOptions.GIDMap) opts := drivers.CreateOpts{ MountLabel: mountLabel, @@ -769,132 +822,67 @@ func (r *layerStore) Put(id string, parentLayer *Layer, names []string, mountLab IDMappings: idMappings, } if moreOptions.TemplateLayer != "" { - if err = r.driver.CreateFromTemplate(id, moreOptions.TemplateLayer, templateIDMappings, parent, parentMappings, &opts, writeable); err != nil { + if err := r.driver.CreateFromTemplate(id, moreOptions.TemplateLayer, templateIDMappings, parent, parentMappings, &opts, writeable); err != nil { + cleanupFailureContext = "creating a layer from template" return nil, -1, errors.Wrapf(err, "error creating copy of template layer %q with ID %q", moreOptions.TemplateLayer, id) } oldMappings = templateIDMappings } else { if writeable { - if err = r.driver.CreateReadWrite(id, parent, &opts); err != nil { + if err := r.driver.CreateReadWrite(id, parent, &opts); err != nil { + cleanupFailureContext = "creating a read-write layer" return nil, -1, errors.Wrapf(err, "error creating read-write layer with ID %q", id) } } else { - if err = r.driver.Create(id, parent, &opts); err != nil { + if err := r.driver.Create(id, parent, &opts); err != nil { + cleanupFailureContext = "creating a read-only layer" return nil, -1, errors.Wrapf(err, "error creating layer with ID %q", id) } } oldMappings = parentMappings } if !reflect.DeepEqual(oldMappings.UIDs(), idMappings.UIDs()) || !reflect.DeepEqual(oldMappings.GIDs(), idMappings.GIDs()) { - if err = r.driver.UpdateLayerIDMap(id, oldMappings, idMappings, mountLabel); err != nil { - // We don't have a record of this layer, but at least - // try to clean it up underneath us. - if err2 := r.driver.Remove(id); err2 != nil { - logrus.Errorf("While recovering from a failure creating in UpdateLayerIDMap, error deleting layer %#v: %v", id, err2) - } + if err := r.driver.UpdateLayerIDMap(id, oldMappings, idMappings, mountLabel); err != nil { + cleanupFailureContext = "in UpdateLayerIDMap" return nil, -1, err } } if len(templateTSdata) > 0 { if err := os.MkdirAll(filepath.Dir(r.tspath(id)), 0o700); err != nil { - // We don't have a record of this layer, but at least - // try to clean it up underneath us. - if err2 := r.driver.Remove(id); err2 != nil { - logrus.Errorf("While recovering from a failure creating in UpdateLayerIDMap, error deleting layer %#v: %v", id, err2) - } + cleanupFailureContext = "creating tar-split parent directory for a copy from template" return nil, -1, err } - if err = ioutils.AtomicWriteFile(r.tspath(id), templateTSdata, 0o600); err != nil { - // We don't have a record of this layer, but at least - // try to clean it up underneath us. - if err2 := r.driver.Remove(id); err2 != nil { - logrus.Errorf("While recovering from a failure creating in UpdateLayerIDMap, error deleting layer %#v: %v", id, err2) - } + if err := ioutils.AtomicWriteFile(r.tspath(id), templateTSdata, 0o600); err != nil { + cleanupFailureContext = "creating a tar-split copy from template" return nil, -1, err } } - if err == nil { - layer = &Layer{ - ID: id, - Parent: parent, - Names: names, - MountLabel: mountLabel, - Metadata: templateMetadata, - Created: time.Now().UTC(), - CompressedDigest: templateCompressedDigest, - CompressedSize: templateCompressedSize, - UncompressedDigest: templateUncompressedDigest, - UncompressedSize: templateUncompressedSize, - CompressionType: templateCompressionType, - UIDs: templateUIDs, - GIDs: templateGIDs, - Flags: make(map[string]interface{}), - UIDMap: copyIDMap(moreOptions.UIDMap), - GIDMap: copyIDMap(moreOptions.GIDMap), - BigDataNames: []string{}, - } - r.layers = append(r.layers, layer) - r.idindex.Add(id) - r.byid[id] = layer - for _, name := range names { - r.byname[name] = layer - } - for flag, value := range flags { - layer.Flags[flag] = value - } - savedIncompleteLayer := false - if diff != nil { - layer.Flags[incompleteFlag] = true - err = r.Save() - if err != nil { - // We don't have a record of this layer, but at least - // try to clean it up underneath us. - if err2 := r.driver.Remove(id); err2 != nil { - logrus.Errorf("While recovering from a failure saving incomplete layer metadata, error deleting layer %#v: %v", id, err2) - } - return nil, -1, err - } - savedIncompleteLayer = true - size, err = r.applyDiffWithOptions(layer.ID, moreOptions, diff) - if err != nil { - if err2 := r.Delete(layer.ID); err2 != nil { - // Either a driver error or an error saving. - // We now have a layer that's been marked for - // deletion but which we failed to remove. - logrus.Errorf("While recovering from a failure applying layer diff, error deleting layer %#v: %v", layer.ID, err2) - } - return nil, -1, err - } - delete(layer.Flags, incompleteFlag) - } else { - // applyDiffWithOptions in the `diff != nil` case handles this bit for us - if layer.CompressedDigest != "" { - r.bycompressedsum[layer.CompressedDigest] = append(r.bycompressedsum[layer.CompressedDigest], layer.ID) - } - if layer.UncompressedDigest != "" { - r.byuncompressedsum[layer.UncompressedDigest] = append(r.byuncompressedsum[layer.UncompressedDigest], layer.ID) - } - } - err = r.Save() + + var size int64 = -1 + if diff != nil { + size, err = r.applyDiffWithOptions(layer.ID, moreOptions, diff) if err != nil { - if savedIncompleteLayer { - if err2 := r.Delete(layer.ID); err2 != nil { - // Either a driver error or an error saving. - // We now have a layer that's been marked for - // deletion but which we failed to remove. - logrus.Errorf("While recovering from a failure saving finished layer metadata, error deleting layer %#v: %v", layer.ID, err2) - } - } else { - // We don't have a record of this layer, but at least - // try to clean it up underneath us. - if err2 := r.driver.Remove(id); err2 != nil { - logrus.Errorf("While recovering from a failure saving finished layer metadata, error deleting layer %#v in graph driver: %v", id, err2) - } - } + cleanupFailureContext = "applying layer diff" return nil, -1, err } - layer = copyLayer(layer) + } else { + // applyDiffWithOptions in the `diff != nil` case handles this bit for us + if layer.CompressedDigest != "" { + r.bycompressedsum[layer.CompressedDigest] = append(r.bycompressedsum[layer.CompressedDigest], layer.ID) + } + if layer.UncompressedDigest != "" { + r.byuncompressedsum[layer.UncompressedDigest] = append(r.byuncompressedsum[layer.UncompressedDigest], layer.ID) + } } + delete(layer.Flags, incompleteFlag) + err = r.Save() + if err != nil { + cleanupFailureContext = "saving finished layer metadata" + return nil, -1, err + } + + layer = copyLayer(layer) + succeeded = true return layer, size, err }