Merge pull request #3365 from brackendawson/3122-remove-workaround

Remove workaround from 2.1.1 for faulty 2.1.0 manifest links

registry/storage/linkedblobstore.go

@@ -32,13 +32,11 @@ type linkedBlobStore struct {
 	deleteEnabled          bool
 	resumableDigestEnabled bool
 
-	// linkPathFns specifies one or more path functions allowing one to
-	// control the repository blob link set to which the blob store
-	// dispatches. This is required because manifest and layer blobs have not
-	// yet been fully merged. At some point, this functionality should be
-	// removed the blob links folder should be merged. The first entry is
-	// treated as the "canonical" link location and will be used for writes.
-	linkPathFns []linkPathFunc
+	// linkPath allows one to control the repository blob link set to which
+	// the blob store dispatches. This is required because manifest and layer
+	// blobs have not yet been fully merged. At some point, this functionality
+	// should be removed an the blob links folder should be merged.
+	linkPath linkPathFunc
 
 	// linkDirectoryPathSpec locates the root directories in which one might find links
 	linkDirectoryPathSpec pathSpec
@@ -338,16 +336,13 @@ func (lbs *linkedBlobStore) linkBlob(ctx context.Context, canonical distribution
 	// Don't make duplicate links.
 	seenDigests := make(map[digest.Digest]struct{}, len(dgsts))
 
-	// only use the first link
-	linkPathFn := lbs.linkPathFns[0]
-
 	for _, dgst := range dgsts {
 		if _, seen := seenDigests[dgst]; seen {
 			continue
 		}
 		seenDigests[dgst] = struct{}{}
 
-		blobLinkPath, err := linkPathFn(lbs.repository.Named().Name(), dgst)
+		blobLinkPath, err := lbs.linkPath(lbs.repository.Named().Name(), dgst)
 		if err != nil {
 			return err
 		}
@@ -364,46 +359,31 @@ type linkedBlobStatter struct {
 	*blobStore
 	repository distribution.Repository
 
-	// linkPathFns specifies one or more path functions allowing one to
-	// control the repository blob link set to which the blob store
-	// dispatches. This is required because manifest and layer blobs have not
-	// yet been fully merged. At some point, this functionality should be
-	// removed an the blob links folder should be merged. The first entry is
-	// treated as the "canonical" link location and will be used for writes.
-	linkPathFns []linkPathFunc
+	// linkPath allows one to control the repository blob link set to which
+	// the blob store dispatches. This is required because manifest and layer
+	// blobs have not yet been fully merged. At some point, this functionality
+	// should be removed an the blob links folder should be merged.
+	linkPath linkPathFunc
 }
 
 var _ distribution.BlobDescriptorService = &linkedBlobStatter{}
 
 func (lbs *linkedBlobStatter) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) {
-	var (
-		found  bool
-		target digest.Digest
-	)
-
-	// try the many link path functions until we get success or an error that
-	// is not PathNotFoundError.
-	for _, linkPathFn := range lbs.linkPathFns {
-		var err error
-		target, err = lbs.resolveWithLinkFunc(ctx, dgst, linkPathFn)
-
-		if err == nil {
-			found = true
-			break // success!
-		}
+	blobLinkPath, err := lbs.linkPath(lbs.repository.Named().Name(), dgst)
+	if err != nil {
+		return distribution.Descriptor{}, err
+	}
 
+	target, err := lbs.blobStore.readlink(ctx, blobLinkPath)
+	if err != nil {
 		switch err := err.(type) {
 		case driver.PathNotFoundError:
-			// do nothing, just move to the next linkPathFn
+			return distribution.Descriptor{}, distribution.ErrBlobUnknown
 		default:
 			return distribution.Descriptor{}, err
 		}
 	}
 
-	if !found {
-		return distribution.Descriptor{}, distribution.ErrBlobUnknown
-	}
-
 	if target != dgst {
 		// Track when we are doing cross-digest domain lookups. ie, sha512 to sha256.
 		dcontext.GetLogger(ctx).Warnf("looking up blob with canonical target: %v -> %v", dgst, target)
@@ -416,37 +396,12 @@ func (lbs *linkedBlobStatter) Stat(ctx context.Context, dgst digest.Digest) (dis
 }
 
 func (lbs *linkedBlobStatter) Clear(ctx context.Context, dgst digest.Digest) (err error) {
-	// clear any possible existence of a link described in linkPathFns
-	for _, linkPathFn := range lbs.linkPathFns {
-		blobLinkPath, err := linkPathFn(lbs.repository.Named().Name(), dgst)
-		if err != nil {
-			return err
-		}
-
-		err = lbs.blobStore.driver.Delete(ctx, blobLinkPath)
-		if err != nil {
-			switch err := err.(type) {
-			case driver.PathNotFoundError:
-				continue // just ignore this error and continue
-			default:
-				return err
-			}
-		}
-	}
-
-	return nil
-}
-
-// resolveTargetWithFunc allows us to read a link to a resource with different
-// linkPathFuncs to let us try a few different paths before returning not
-// found.
-func (lbs *linkedBlobStatter) resolveWithLinkFunc(ctx context.Context, dgst digest.Digest, linkPathFn linkPathFunc) (digest.Digest, error) {
-	blobLinkPath, err := linkPathFn(lbs.repository.Named().Name(), dgst)
+	blobLinkPath, err := lbs.linkPath(lbs.repository.Named().Name(), dgst)
 	if err != nil {
-		return "", err
+		return err
 	}
 
-	return lbs.blobStore.readlink(ctx, blobLinkPath)
+	return lbs.blobStore.driver.Delete(ctx, blobLinkPath)
 }
 
 func (lbs *linkedBlobStatter) SetDescriptor(ctx context.Context, dgst digest.Digest, desc distribution.Descriptor) error {

registry/storage/registry.go

@@ -215,19 +215,12 @@ func (repo *repository) Tags(ctx context.Context) distribution.TagService {
 // may be context sensitive in the future. The instance should be used similar
 // to a request local.
 func (repo *repository) Manifests(ctx context.Context, options ...distribution.ManifestServiceOption) (distribution.ManifestService, error) {
-	manifestLinkPathFns := []linkPathFunc{
-		// NOTE(stevvooe): Need to search through multiple locations since
-		// 2.1.0 unintentionally linked into  _layers.
-		manifestRevisionLinkPath,
-		blobLinkPath,
-	}
-
 	manifestDirectoryPathSpec := manifestRevisionsPathSpec{name: repo.name.Name()}
 
 	var statter distribution.BlobDescriptorService = &linkedBlobStatter{
-		blobStore:   repo.blobStore,
-		repository:  repo,
-		linkPathFns: manifestLinkPathFns,
+		blobStore:  repo.blobStore,
+		repository: repo,
+		linkPath:   manifestRevisionLinkPath,
 	}
 
 	if repo.registry.blobDescriptorServiceFactory != nil {
@@ -243,7 +236,7 @@ func (repo *repository) Manifests(ctx context.Context, options ...distribution.M
 
 		// TODO(stevvooe): linkPath limits this blob store to only
 		// manifests. This instance cannot be used for blob checks.
-		linkPathFns:           manifestLinkPathFns,
+		linkPath:              manifestRevisionLinkPath,
 		linkDirectoryPathSpec: manifestDirectoryPathSpec,
 	}
 
@@ -306,9 +299,9 @@ func (repo *repository) Manifests(ctx context.Context, options ...distribution.M
 // to a request local.
 func (repo *repository) Blobs(ctx context.Context) distribution.BlobStore {
 	var statter distribution.BlobDescriptorService = &linkedBlobStatter{
-		blobStore:   repo.blobStore,
-		repository:  repo,
-		linkPathFns: []linkPathFunc{blobLinkPath},
+		blobStore:  repo.blobStore,
+		repository: repo,
+		linkPath:   blobLinkPath,
 	}
 
 	if repo.descriptorCache != nil {
@@ -329,7 +322,7 @@ func (repo *repository) Blobs(ctx context.Context) distribution.BlobStore {
 
 		// TODO(stevvooe): linkPath limits this blob store to only layers.
 		// This instance cannot be used for manifest checks.
-		linkPathFns:            []linkPathFunc{blobLinkPath},
+		linkPath:               blobLinkPath,
 		linkDirectoryPathSpec:  layersPathSpec{name: repo.name.Name()},
 		deleteEnabled:          repo.registry.deleteEnabled,
 		resumableDigestEnabled: repo.resumableDigestEnabled,

registry/storage/tagstore.go

@@ -124,14 +124,13 @@ func (ts *tagStore) linkedBlobStore(ctx context.Context, tag string) *linkedBlob
 		blobStore:  ts.blobStore,
 		repository: ts.repository,
 		ctx:        ctx,
-		linkPathFns: []linkPathFunc{func(name string, dgst digest.Digest) (string, error) {
+		linkPath: func(name string, dgst digest.Digest) (string, error) {
 			return pathFor(manifestTagIndexEntryLinkPathSpec{
 				name:     name,
 				tag:      tag,
 				revision: dgst,
 			})
-
-		}},
+		},
 	}
 }
 
@@ -185,13 +184,13 @@ func (ts *tagStore) ManifestDigests(ctx context.Context, tag string) ([]digest.D
 	lbs := &linkedBlobStore{
 		blobStore: ts.blobStore,
 		blobAccessController: &linkedBlobStatter{
-			blobStore:   ts.blobStore,
-			repository:  ts.repository,
-			linkPathFns: []linkPathFunc{manifestRevisionLinkPath},
+			blobStore:  ts.blobStore,
+			repository: ts.repository,
+			linkPath:   manifestRevisionLinkPath,
 		},
-		repository:  ts.repository,
-		ctx:         ctx,
-		linkPathFns: []linkPathFunc{tagLinkPath},
+		repository: ts.repository,
+		ctx:        ctx,
+		linkPath:   tagLinkPath,
 		linkDirectoryPathSpec: manifestTagIndexPathSpec{
 			name: ts.repository.Named().Name(),
 			tag:  tag,