manifest: Store layers inside manifests consistently as values.

Commit 1829fb61 ("manifest: Fix crash on startup when trying to clean up
unused files (#5840)") changed the config layer stored in manifests
from a pointer to a value. This was done in order to avoid potential
nil pointer dereferences after it is deserialized from JSON in the
event that the field is missing.

This changes the Layers slice to also be stored by value. This enables
consistency in handling across the two objects.

server/images.go

@@ -373,7 +373,7 @@ func CreateModel(ctx context.Context, name model.Name, modelFileDir, quantizatio
 	var messages []*api.Message
 	parameters := make(map[string]any)
 
-	var layers []*Layer
+	var layers []Layer
 	for _, c := range modelfile.Commands {
 		mediatype := fmt.Sprintf("application/vnd.ollama.image.%s", c.Name)
 
@@ -499,7 +499,7 @@ func CreateModel(ctx context.Context, name model.Name, modelFileDir, quantizatio
 
 			if c.Name != "license" {
 				// replace
-				layers = slices.DeleteFunc(layers, func(layer *Layer) bool {
+				layers = slices.DeleteFunc(layers, func(layer Layer) bool {
 					if layer.MediaType != mediatype {
 						return false
 					}
@@ -545,7 +545,7 @@ func CreateModel(ctx context.Context, name model.Name, modelFileDir, quantizatio
 	}
 
 	var err2 error
-	layers = slices.DeleteFunc(layers, func(layer *Layer) bool {
+	layers = slices.DeleteFunc(layers, func(layer Layer) bool {
 		switch layer.MediaType {
 		case "application/vnd.ollama.image.message":
 			// if there are new messages, remove the inherited ones
@@ -839,10 +839,10 @@ func PushModel(ctx context.Context, name string, regOpts *registryOptions, fn fu
 		return err
 	}
 
-	var layers []*Layer
+	var layers []Layer
 	layers = append(layers, manifest.Layers...)
 	if manifest.Config.Digest != "" {
-		layers = append(layers, &manifest.Config)
+		layers = append(layers, manifest.Config)
 	}
 
 	for _, layer := range layers {
@@ -911,10 +911,10 @@ func PullModel(ctx context.Context, name string, regOpts *registryOptions, fn fu
 		return fmt.Errorf("pull model manifest: %s", err)
 	}
 
-	var layers []*Layer
+	var layers []Layer
 	layers = append(layers, manifest.Layers...)
 	if manifest.Config.Digest != "" {
-		layers = append(layers, &manifest.Config)
+		layers = append(layers, manifest.Config)
 	}
 
 	skipVerify := make(map[string]bool)

server/layer.go

@@ -16,15 +16,15 @@ type Layer struct {
 	status    string
 }
 
-func NewLayer(r io.Reader, mediatype string) (*Layer, error) {
+func NewLayer(r io.Reader, mediatype string) (Layer, error) {
 	blobs, err := GetBlobsPath("")
 	if err != nil {
-		return nil, err
+		return Layer{}, err
 	}
 
 	temp, err := os.CreateTemp(blobs, "sha256-")
 	if err != nil {
-		return nil, err
+		return Layer{}, err
 	}
 	defer temp.Close()
 	defer os.Remove(temp.Name())
@@ -32,28 +32,28 @@ func NewLayer(r io.Reader, mediatype string) (*Layer, error) {
 	sha256sum := sha256.New()
 	n, err := io.Copy(io.MultiWriter(temp, sha256sum), r)
 	if err != nil {
-		return nil, err
+		return Layer{}, err
 	}
 
 	if err := temp.Close(); err != nil {
-		return nil, err
+		return Layer{}, err
 	}
 
 	digest := fmt.Sprintf("sha256:%x", sha256sum.Sum(nil))
 	blob, err := GetBlobsPath(digest)
 	if err != nil {
-		return nil, err
+		return Layer{}, err
 	}
 
 	status := "using existing layer"
 	if _, err := os.Stat(blob); err != nil {
 		status = "creating new layer"
 		if err := os.Rename(temp.Name(), blob); err != nil {
-			return nil, err
+			return Layer{}, err
 		}
 	}
 
-	return &Layer{
+	return Layer{
 		MediaType: mediatype,
 		Digest:    digest,
 		Size:      n,
@@ -61,22 +61,22 @@ func NewLayer(r io.Reader, mediatype string) (*Layer, error) {
 	}, nil
 }
 
-func NewLayerFromLayer(digest, mediatype, from string) (*Layer, error) {
+func NewLayerFromLayer(digest, mediatype, from string) (Layer, error) {
 	if digest == "" {
-		return nil, errors.New("creating new layer from layer with empty digest")
+		return Layer{}, errors.New("creating new layer from layer with empty digest")
 	}
 
 	blob, err := GetBlobsPath(digest)
 	if err != nil {
-		return nil, err
+		return Layer{}, err
 	}
 
 	fi, err := os.Stat(blob)
 	if err != nil {
-		return nil, err
+		return Layer{}, err
 	}
 
-	return &Layer{
+	return Layer{
 		MediaType: mediatype,
 		Digest:    digest,
 		Size:      fi.Size(),
@@ -109,7 +109,7 @@ func (l *Layer) Remove() error {
 	}
 
 	for _, m := range ms {
-		for _, layer := range append(m.Layers, &m.Config) {
+		for _, layer := range append(m.Layers, m.Config) {
 			if layer.Digest == l.Digest {
 				// something is using this layer
 				return nil

server/manifest.go

@@ -17,7 +17,7 @@ type Manifest struct {
 	SchemaVersion int     `json:"schemaVersion"`
 	MediaType     string  `json:"mediaType"`
 	Config        Layer   `json:"config"`
-	Layers        []*Layer `json:"layers"`
+	Layers        []Layer `json:"layers"`
 
 	filepath string
 	fi       os.FileInfo
@@ -25,7 +25,7 @@ type Manifest struct {
 }
 
 func (m *Manifest) Size() (size int64) {
-	for _, layer := range append(m.Layers, &m.Config) {
+	for _, layer := range append(m.Layers, m.Config) {
 		size += layer.Size
 	}
 
@@ -46,7 +46,7 @@ func (m *Manifest) Remove() error {
 }
 
 func (m *Manifest) RemoveLayers() error {
-	for _, layer := range append(m.Layers, &m.Config) {
+	for _, layer := range append(m.Layers, m.Config) {
 		if layer.Digest != "" {
 			if err := layer.Remove(); errors.Is(err, os.ErrNotExist) {
 				slog.Debug("layer does not exist", "digest", layer.Digest)
@@ -95,7 +95,7 @@ func ParseNamedManifest(n model.Name) (*Manifest, error) {
 	return &m, nil
 }
 
-func WriteManifest(name model.Name, config *Layer, layers []*Layer) error {
+func WriteManifest(name model.Name, config Layer, layers []Layer) error {
 	manifests, err := GetManifestPath()
 	if err != nil {
 		return err
@@ -115,7 +115,7 @@ func WriteManifest(name model.Name, config *Layer, layers []*Layer) error {
 	m := Manifest{
 		SchemaVersion: 2,
 		MediaType:     "application/vnd.docker.distribution.manifest.v2+json",
-		Config:        *config,
+		Config:        config,
 		Layers:        layers,
 	}
 

server/model.go

@@ -26,7 +26,7 @@ import (
 var intermediateBlobs map[string]string = make(map[string]string)
 
 type layerGGML struct {
-	*Layer
+	Layer
 	*llm.GGML
 }
 

server/routes_delete_test.go

@@ -98,7 +98,7 @@ func TestDeleteDuplicateLayers(t *testing.T) {
 	}
 
 	// create a manifest with duplicate layers
-	if err := WriteManifest(n, config, []*Layer{config}); err != nil {
+	if err := WriteManifest(n, config, []Layer{config}); err != nil {
 		t.Fatal(err)
 	}
 

server/upload.go

@@ -26,7 +26,7 @@ import (
 var blobUploadManager sync.Map
 
 type blobUpload struct {
-	*Layer
+	Layer
 
 	Total     int64
 	Completed atomic.Int64
@@ -362,7 +362,7 @@ func (p *progressWriter) Rollback() {
 	p.written = 0
 }
 
-func uploadBlob(ctx context.Context, mp ModelPath, layer *Layer, opts *registryOptions, fn func(api.ProgressResponse)) error {
+func uploadBlob(ctx context.Context, mp ModelPath, layer Layer, opts *registryOptions, fn func(api.ProgressResponse)) error {
 	requestURL := mp.BaseURL()
 	requestURL = requestURL.JoinPath("v2", mp.GetNamespaceRepository(), "blobs", layer.Digest)