From 6140369208a9697acd699bf77efb9de84149955e Mon Sep 17 00:00:00 2001 From: Valentin Rothberg Date: Fri, 12 Feb 2021 17:23:01 +0100 Subject: [PATCH] make layer-tree lookup errors non-fatal Internally, Podman constructs a tree of layers in containers/storage to quickly compute relations among layers and hence images. To compute the tree, we intersect all local layers with all local images. So far, lookup errors have been fatal which has turned out to be a mistake since it seems fairly easy to cause storage corruptions, for instance, when killing builds. In that case, a (partial) image may list a layer which does not exist (anymore). Since the errors were fatal, there was no easy way to clean up and many commands were erroring out. To improve usability, turn the fatal errors into warnings that guide the user into resolving the issue. In this case, a `podman system reset` may be the approriate way for now. [NO TESTS NEEDED] because I have no reliable way to force it. [1] https://github.com/containers/podman/issues/8148#issuecomment-778253474 Signed-off-by: Valentin Rothberg --- libpod/image/layer_tree.go | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/libpod/image/layer_tree.go b/libpod/image/layer_tree.go index 18101575e6..dde39dba15 100644 --- a/libpod/image/layer_tree.go +++ b/libpod/image/layer_tree.go @@ -5,6 +5,7 @@ import ( ociv1 "github.com/opencontainers/image-spec/specs-go/v1" "github.com/pkg/errors" + "github.com/sirupsen/logrus" ) // layerTree is an internal representation of local layers. @@ -84,7 +85,12 @@ func (ir *Runtime) layerTree() (*layerTree, error) { } node, exists := tree.nodes[topLayer] if !exists { - return nil, errors.Errorf("top layer %s of image %s not found in layer tree", img.TopLayer(), img.ID()) + // Note: erroring out in this case has turned out having been a + // mistake. Users may not be able to recover, so we're now + // throwing a warning to guide them to resolve the issue and + // turn the errors non-fatal. + logrus.Warnf("Top layer %s of image %s not found in layer tree. The storage may be corrupted, consider running `podman system reset`.", topLayer, img.ID()) + continue } node.images = append(node.images, img) } @@ -107,7 +113,12 @@ func (t *layerTree) children(ctx context.Context, parent *Image, all bool) ([]st parentNode, exists := t.nodes[parent.TopLayer()] if !exists { - return nil, errors.Errorf("layer not found in layer tree: %q", parent.TopLayer()) + // Note: erroring out in this case has turned out having been a + // mistake. Users may not be able to recover, so we're now + // throwing a warning to guide them to resolve the issue and + // turn the errors non-fatal. + logrus.Warnf("Layer %s not found in layer. The storage may be corrupted, consider running `podman system reset`.", parent.TopLayer()) + return children, nil } parentID := parent.ID()