Merge pull request #51412 from austinvazquez/use-regular-slice-for-disk-usage

api/types: use regular slices for disk usage types

api/docs/v1.52.yaml

@@ -2096,7 +2096,6 @@ definitions:
         type: "array"
         x-omitempty: true
         items:
-          x-nullable: true
           x-go-type:
             type: Summary
 
@@ -2279,7 +2278,6 @@ definitions:
         type: "array"
         x-omitempty: true
         items:
-          x-nullable: true
           x-go-type:
             type: Volume
 
@@ -2893,7 +2891,6 @@ definitions:
         type: "array"
         x-omitempty: true
         items:
-          x-nullable: true
           x-go-type:
             type: CacheRecord
 
@@ -5617,7 +5614,6 @@ definitions:
         type: "array"
         x-omitempty: true
         items:
-          x-nullable: true
           x-go-type:
             type: Summary
 

api/swagger.yaml

@@ -2096,7 +2096,6 @@ definitions:
         type: "array"
         x-omitempty: true
         items:
-          x-nullable: true
           x-go-type:
             type: Summary
 
@@ -2279,7 +2278,6 @@ definitions:
         type: "array"
         x-omitempty: true
         items:
-          x-nullable: true
           x-go-type:
             type: Volume
 
@@ -2893,7 +2891,6 @@ definitions:
         type: "array"
         x-omitempty: true
         items:
-          x-nullable: true
           x-go-type:
             type: CacheRecord
 
@@ -5617,7 +5614,6 @@ definitions:
         type: "array"
         x-omitempty: true
         items:
-          x-nullable: true
           x-go-type:
             type: Summary
 

api/types/build/disk_usage.go

@@ -17,7 +17,7 @@ type DiskUsage struct {
 
 	// List of build cache records.
 	//
-	Items []*CacheRecord `json:"Items,omitempty"`
+	Items []CacheRecord `json:"Items,omitempty"`
 
 	// Disk space that can be reclaimed by removing inactive build cache records.
 	//

api/types/container/disk_usage.go

@@ -17,7 +17,7 @@ type DiskUsage struct {
 
 	// List of container summaries.
 	//
-	Items []*Summary `json:"Items,omitempty"`
+	Items []Summary `json:"Items,omitempty"`
 
 	// Disk space that can be reclaimed by removing inactive containers.
 	//

api/types/image/disk_usage.go

@@ -17,7 +17,7 @@ type DiskUsage struct {
 
 	// List of image summaries.
 	//
-	Items []*Summary `json:"Items,omitempty"`
+	Items []Summary `json:"Items,omitempty"`
 
 	// Disk space that can be reclaimed by removing unused images.
 	//

api/types/system/disk_usage.go

@@ -37,14 +37,14 @@ type LegacyDiskUsage struct {
 	LayersSize int64 `json:"LayersSize,omitempty"`
 
 	// Deprecated: kept to maintain backwards compatibility with API < v1.52, use [ImagesDiskUsage.Items] instead.
-	Images []*image.Summary `json:"Images,omitempty"`
+	Images []image.Summary `json:"Images,omitzero"`
 
 	// Deprecated: kept to maintain backwards compatibility with API < v1.52, use [ContainersDiskUsage.Items] instead.
-	Containers []*container.Summary `json:"Containers,omitempty"`
+	Containers []container.Summary `json:"Containers,omitzero"`
 
 	// Deprecated: kept to maintain backwards compatibility with API < v1.52, use [VolumesDiskUsage.Items] instead.
-	Volumes []*volume.Volume `json:"Volumes,omitempty"`
+	Volumes []volume.Volume `json:"Volumes,omitzero"`
 
 	// Deprecated: kept to maintain backwards compatibility with API < v1.52, use [BuildCacheDiskUsage.Items] instead.
-	BuildCache []*build.CacheRecord `json:"BuildCache,omitempty"`
+	BuildCache []build.CacheRecord `json:"BuildCache,omitzero"`
 }

api/types/volume/disk_usage.go

@@ -17,7 +17,7 @@ type DiskUsage struct {
 
 	// List of volumes.
 	//
-	Items []*Volume `json:"Items,omitempty"`
+	Items []Volume `json:"Items,omitempty"`
 
 	// Disk space that can be reclaimed by removing inactive volumes.
 	//

client/system_disk_usage.go

@@ -5,12 +5,15 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/url"
+	"slices"
+	"strings"
 
 	"github.com/moby/moby/api/types/build"
 	"github.com/moby/moby/api/types/container"
 	"github.com/moby/moby/api/types/image"
 	"github.com/moby/moby/api/types/system"
 	"github.com/moby/moby/api/types/volume"
+	"github.com/moby/moby/client/pkg/versions"
 )
 
 // DiskUsageOptions holds parameters for [Client.DiskUsage] operations.
@@ -151,103 +154,166 @@ func (cli *Client) DiskUsage(ctx context.Context, options DiskUsageOptions) (Dis
 		return DiskUsageResult{}, fmt.Errorf("Error retrieving disk usage: %v", err)
 	}
 
-	var (
-		r              DiskUsageResult
-		imagesFrom     = []*image.Summary{}
-		containersFrom = []*container.Summary{}
-		volumesFrom    = []*volume.Volume{}
-		buildCacheFrom = []*build.CacheRecord{}
-	)
+	// Generate result from a legacy response.
+	if versions.LessThan(cli.version, "1.52") {
+		return diskUsageResultFromLegacyAPI(&du), nil
+	}
 
-	if du.ImageUsage != nil {
+	var r DiskUsageResult
+	if idu := du.ImageUsage; idu != nil {
 		r.Images = ImagesDiskUsage{
-			ActiveImages: du.ImageUsage.ActiveImages,
-			Reclaimable:  du.ImageUsage.Reclaimable,
-			TotalImages:  du.ImageUsage.TotalImages,
-			TotalSize:    du.ImageUsage.TotalSize,
+			ActiveImages: idu.ActiveImages,
+			Reclaimable:  idu.Reclaimable,
+			TotalImages:  idu.TotalImages,
+			TotalSize:    idu.TotalSize,
 		}
 
 		if options.Verbose {
-			imagesFrom = du.ImageUsage.Items
-		}
-	} else {
-		// Fallback for legacy response.
-		r.Images = ImagesDiskUsage{
-			TotalSize: du.LayersSize,
-		}
-
-		if du.Images != nil && options.Verbose {
-			imagesFrom = du.Images
+			r.Images.Items = slices.Clone(idu.Items)
 		}
 	}
 
-	r.Images.Items = make([]image.Summary, len(imagesFrom))
-	for i, ii := range imagesFrom {
-		r.Images.Items[i] = *ii
-	}
-
-	if du.ContainerUsage != nil {
+	if cdu := du.ContainerUsage; cdu != nil {
 		r.Containers = ContainersDiskUsage{
-			ActiveContainers: du.ContainerUsage.ActiveContainers,
-			Reclaimable:      du.ContainerUsage.Reclaimable,
-			TotalContainers:  du.ContainerUsage.TotalContainers,
-			TotalSize:        du.ContainerUsage.TotalSize,
+			ActiveContainers: cdu.ActiveContainers,
+			Reclaimable:      cdu.Reclaimable,
+			TotalContainers:  cdu.TotalContainers,
+			TotalSize:        cdu.TotalSize,
 		}
 
 		if options.Verbose {
-			containersFrom = du.ContainerUsage.Items
+			r.Containers.Items = slices.Clone(cdu.Items)
 		}
-	} else if du.Containers != nil && options.Verbose {
-		// Fallback for legacy response.
-		containersFrom = du.Containers
 	}
 
-	r.Containers.Items = make([]container.Summary, len(containersFrom))
-	for i, c := range containersFrom {
-		r.Containers.Items[i] = *c
-	}
-
-	if du.BuildCacheUsage != nil {
+	if bdu := du.BuildCacheUsage; bdu != nil {
 		r.BuildCache = BuildCacheDiskUsage{
-			ActiveBuildCacheRecords: du.BuildCacheUsage.ActiveBuildCacheRecords,
-			Reclaimable:             du.BuildCacheUsage.Reclaimable,
-			TotalBuildCacheRecords:  du.BuildCacheUsage.TotalBuildCacheRecords,
-			TotalSize:               du.BuildCacheUsage.TotalSize,
+			ActiveBuildCacheRecords: bdu.ActiveBuildCacheRecords,
+			Reclaimable:             bdu.Reclaimable,
+			TotalBuildCacheRecords:  bdu.TotalBuildCacheRecords,
+			TotalSize:               bdu.TotalSize,
 		}
 
 		if options.Verbose {
-			buildCacheFrom = du.BuildCacheUsage.Items
+			r.BuildCache.Items = slices.Clone(bdu.Items)
 		}
-	} else if du.BuildCache != nil && options.Verbose {
-		// Fallback for legacy response.
-		buildCacheFrom = du.BuildCache
 	}
 
-	r.BuildCache.Items = make([]build.CacheRecord, len(buildCacheFrom))
-	for i, b := range buildCacheFrom {
-		r.BuildCache.Items[i] = *b
-	}
-
-	if du.VolumeUsage != nil {
+	if vdu := du.VolumeUsage; vdu != nil {
 		r.Volumes = VolumesDiskUsage{
-			ActiveVolumes: du.VolumeUsage.ActiveVolumes,
-			Reclaimable:   du.VolumeUsage.Reclaimable,
-			TotalSize:     du.VolumeUsage.TotalSize,
-			TotalVolumes:  du.VolumeUsage.TotalVolumes,
+			ActiveVolumes: vdu.ActiveVolumes,
+			Reclaimable:   vdu.Reclaimable,
+			TotalVolumes:  vdu.TotalVolumes,
+			TotalSize:     vdu.TotalSize,
 		}
 
 		if options.Verbose {
-			volumesFrom = du.VolumeUsage.Items
+			r.Volumes.Items = slices.Clone(vdu.Items)
 		}
-	} else if du.Volumes != nil && options.Verbose {
-		// Fallback for legacy response.
-		volumesFrom = du.Volumes
-	}
-
-	r.Volumes.Items = make([]volume.Volume, len(volumesFrom))
-	for i, v := range volumesFrom {
-		r.Volumes.Items[i] = *v
 	}
 
 	return r, nil
 }
+
+func diskUsageResultFromLegacyAPI(du *system.DiskUsage) DiskUsageResult {
+	return DiskUsageResult{
+		Images:     imageDiskUsageFromLegacyAPI(du),
+		Containers: containerDiskUsageFromLegacyAPI(du),
+		BuildCache: buildCacheDiskUsageFromLegacyAPI(du),
+		Volumes:    volumeDiskUsageFromLegacyAPI(du),
+	}
+}
+
+func imageDiskUsageFromLegacyAPI(du *system.DiskUsage) ImagesDiskUsage {
+	idu := ImagesDiskUsage{
+		TotalSize:   du.LayersSize,
+		TotalImages: int64(len(du.Images)),
+		Items:       du.Images,
+	}
+
+	var used int64
+	for _, i := range idu.Items {
+		if i.Containers > 0 {
+			idu.ActiveImages++
+
+			if i.Size == -1 || i.SharedSize == -1 {
+				continue
+			}
+			used += (i.Size - i.SharedSize)
+		}
+	}
+
+	if idu.TotalImages > 0 {
+		idu.Reclaimable = idu.TotalSize - used
+	}
+
+	return idu
+}
+
+func containerDiskUsageFromLegacyAPI(du *system.DiskUsage) ContainersDiskUsage {
+	cdu := ContainersDiskUsage{
+		TotalContainers: int64(len(du.Containers)),
+		Items:           du.Containers,
+	}
+
+	var used int64
+	for _, c := range cdu.Items {
+		cdu.TotalSize += c.SizeRw
+		switch strings.ToLower(c.State) {
+		case "running", "paused", "restarting":
+			cdu.ActiveContainers++
+			used += c.SizeRw
+		}
+	}
+
+	cdu.Reclaimable = cdu.TotalSize - used
+	return cdu
+}
+
+func buildCacheDiskUsageFromLegacyAPI(du *system.DiskUsage) BuildCacheDiskUsage {
+	bdu := BuildCacheDiskUsage{
+		TotalBuildCacheRecords: int64(len(du.BuildCache)),
+		Items:                  du.BuildCache,
+	}
+
+	var used int64
+	for _, b := range du.BuildCache {
+		if !b.Shared {
+			bdu.TotalSize += b.Size
+		}
+
+		if b.InUse {
+			bdu.ActiveBuildCacheRecords++
+			if !b.Shared {
+				used += b.Size
+			}
+		}
+	}
+
+	bdu.Reclaimable = bdu.TotalSize - used
+	return bdu
+}
+
+func volumeDiskUsageFromLegacyAPI(du *system.DiskUsage) VolumesDiskUsage {
+	vdu := VolumesDiskUsage{
+		TotalVolumes: int64(len(du.Volumes)),
+		Items:        du.Volumes,
+	}
+
+	var used int64
+	for _, v := range vdu.Items {
+		// Ignore volumes with no usage data
+		if v.UsageData != nil {
+			if v.UsageData.RefCount > 0 {
+				vdu.ActiveVolumes++
+				used += v.UsageData.Size
+			}
+			if v.UsageData.Size > 0 {
+				vdu.TotalSize += v.UsageData.Size
+			}
+		}
+	}
+
+	vdu.Reclaimable = vdu.TotalSize - used
+	return vdu
+}

client/system_disk_usage_test.go

@@ -33,7 +33,7 @@ func TestDiskUsage(t *testing.T) {
 				TotalImages:  0,
 				Reclaimable:  0,
 				TotalSize:    4096,
-				Items:        []*image.Summary{},
+				Items:        []image.Summary{},
 			},
 		})(req)
 	}))
@@ -131,19 +131,22 @@ func TestDiskUsageWithOptions(t *testing.T) {
 }
 
 func TestLegacyDiskUsage(t *testing.T) {
+	const legacyVersion = "1.51"
 	const expectedURL = "/system/df"
-	client, err := NewClientWithOpts(WithMockClient(func(req *http.Request) (*http.Response, error) {
-		if err := assertRequest(req, http.MethodGet, expectedURL); err != nil {
-			return nil, err
-		}
+	client, err := NewClientWithOpts(
+		WithVersion(legacyVersion),
+		WithMockClient(func(req *http.Request) (*http.Response, error) {
+			if err := assertRequest(req, http.MethodGet, "/v"+legacyVersion+expectedURL); err != nil {
+				return nil, err
+			}
 
-		return mockJSONResponse(http.StatusOK, nil, system.DiskUsage{
-			LegacyDiskUsage: system.LegacyDiskUsage{
-				LayersSize: 4096,
-				Images:     []*image.Summary{},
-			},
-		})(req)
-	}))
+			return mockJSONResponse(http.StatusOK, nil, system.DiskUsage{
+				LegacyDiskUsage: system.LegacyDiskUsage{
+					LayersSize: 4096,
+					Images:     []image.Summary{},
+				},
+			})(req)
+		}))
 	assert.NilError(t, err)
 
 	du, err := client.DiskUsage(context.Background(), DiskUsageOptions{})

daemon/disk_usage.go

@@ -8,6 +8,7 @@ import (
 	"github.com/moby/moby/v2/daemon/internal/filters"
 	"github.com/moby/moby/v2/daemon/server/backend"
 	"github.com/moby/moby/v2/daemon/server/imagebackend"
+	"github.com/moby/moby/v2/internal/sliceutil"
 	"github.com/pkg/errors"
 	"golang.org/x/sync/errgroup"
 )
@@ -51,7 +52,7 @@ func (daemon *Daemon) containerDiskUsage(ctx context.Context, verbose bool) (*ba
 		du.ActiveCount = activeCount
 
 		if verbose {
-			du.Items = containers
+			du.Items = sliceutil.Deref(containers)
 		}
 
 		return du, nil
@@ -96,7 +97,7 @@ func (daemon *Daemon) imageDiskUsage(ctx context.Context, verbose bool) (*backen
 		du.ActiveCount = activeCount
 
 		if verbose {
-			du.Items = images
+			du.Items = sliceutil.Deref(images)
 		}
 
 		return du, nil
@@ -130,7 +131,7 @@ func (daemon *Daemon) localVolumesSize(ctx context.Context, verbose bool) (*back
 		du.ActiveCount = activeCount
 
 		if verbose {
-			du.Items = volumes
+			du.Items = sliceutil.Deref(volumes)
 		}
 
 		return du, nil

daemon/internal/builder-next/builder.go

@@ -150,15 +150,15 @@ func (b *Builder) Cancel(ctx context.Context, id string) error {
 }
 
 // DiskUsage returns a report about space used by build cache
-func (b *Builder) DiskUsage(ctx context.Context) ([]*build.CacheRecord, error) {
+func (b *Builder) DiskUsage(ctx context.Context) ([]build.CacheRecord, error) {
 	duResp, err := b.controller.DiskUsage(ctx, &controlapi.DiskUsageRequest{})
 	if err != nil {
 		return nil, err
 	}
 
-	var items []*build.CacheRecord
+	var items []build.CacheRecord
 	for _, r := range duResp.Record {
-		items = append(items, &build.CacheRecord{
+		items = append(items, build.CacheRecord{
 			ID:          r.ID,
 			Parents:     r.Parents,
 			Type:        r.RecordType,

daemon/server/backend/disk_usage.go

@@ -37,7 +37,7 @@ type BuildCacheDiskUsage struct {
 	TotalCount  int64
 	TotalSize   int64
 	Reclaimable int64
-	Items       []*build.CacheRecord
+	Items       []build.CacheRecord
 }
 
 // ContainerDiskUsage contains disk usage for containers.
@@ -46,7 +46,7 @@ type ContainerDiskUsage struct {
 	TotalCount  int64
 	TotalSize   int64
 	Reclaimable int64
-	Items       []*container.Summary
+	Items       []container.Summary
 }
 
 // ImageDiskUsage contains disk usage for images.
@@ -55,7 +55,7 @@ type ImageDiskUsage struct {
 	TotalCount  int64
 	TotalSize   int64
 	Reclaimable int64
-	Items       []*image.Summary
+	Items       []image.Summary
 }
 
 // VolumeDiskUsage contains disk usage for volumes.
@@ -64,5 +64,5 @@ type VolumeDiskUsage struct {
 	TotalCount  int64
 	TotalSize   int64
 	Reclaimable int64
-	Items       []*volume.Volume
+	Items       []volume.Volume
 }

daemon/server/router/system/backend.go

@@ -32,7 +32,7 @@ type ClusterBackend interface {
 
 // BuildBackend provides build specific system information.
 type BuildBackend interface {
-	DiskUsage(context.Context) ([]*build.CacheRecord, error)
+	DiskUsage(context.Context) ([]build.CacheRecord, error)
 }
 
 // StatusProvider provides methods to get the swarm status of the current node.

daemon/server/router/system/system_routes.go

@@ -196,7 +196,7 @@ func (s *systemRouter) getDiskUsage(ctx context.Context, w http.ResponseWriter,
 		})
 	}
 
-	var buildCache []*buildtypes.CacheRecord
+	var buildCache []buildtypes.CacheRecord
 	if getBuildCache {
 		eg.Go(func() error {
 			var err error
@@ -204,11 +204,6 @@ func (s *systemRouter) getDiskUsage(ctx context.Context, w http.ResponseWriter,
 			if err != nil {
 				return errors.Wrap(err, "error getting build cache usage")
 			}
-			if buildCache == nil {
-				// Ensure empty `BuildCache` field is represented as empty JSON array(`[]`)
-				// instead of `null` to be consistent with `Images`, `Containers` etc.
-				buildCache = []*buildtypes.CacheRecord{}
-			}
 			return nil
 		})
 	}
@@ -227,8 +222,8 @@ func (s *systemRouter) getDiskUsage(ctx context.Context, w http.ResponseWriter,
 		}
 
 		if legacyFields {
-			v.LayersSize = systemDiskUsage.Images.TotalSize //nolint: staticcheck,SA1019: v.LayersSize is deprecated: kept to maintain backwards compatibility with API < v1.52, use [ImagesDiskUsage.TotalSize] instead.
-			v.Images = systemDiskUsage.Images.Items         //nolint: staticcheck,SA1019: v.Images is deprecated: kept to maintain backwards compatibility with API < v1.52, use [ImagesDiskUsage.Items] instead.
+			v.LayersSize = systemDiskUsage.Images.TotalSize      //nolint: staticcheck,SA1019: v.LayersSize is deprecated: kept to maintain backwards compatibility with API < v1.52, use [ImagesDiskUsage.TotalSize] instead.
+			v.Images = nonNilSlice(systemDiskUsage.Images.Items) //nolint: staticcheck,SA1019: v.Images is deprecated: kept to maintain backwards compatibility with API < v1.52, use [ImagesDiskUsage.Items] instead.
 		} else if verbose {
 			v.ImageUsage.Items = systemDiskUsage.Images.Items
 		}
@@ -242,7 +237,7 @@ func (s *systemRouter) getDiskUsage(ctx context.Context, w http.ResponseWriter,
 		}
 
 		if legacyFields {
-			v.Containers = systemDiskUsage.Containers.Items //nolint: staticcheck,SA1019: v.Containers is deprecated: kept to maintain backwards compatibility with API < v1.52, use [ContainersDiskUsage.Items] instead.
+			v.Containers = nonNilSlice(systemDiskUsage.Containers.Items) //nolint: staticcheck,SA1019: v.Containers is deprecated: kept to maintain backwards compatibility with API < v1.52, use [ContainersDiskUsage.Items] instead.
 		} else if verbose {
 			v.ContainerUsage.Items = systemDiskUsage.Containers.Items
 		}
@@ -256,7 +251,7 @@ func (s *systemRouter) getDiskUsage(ctx context.Context, w http.ResponseWriter,
 		}
 
 		if legacyFields {
-			v.Volumes = systemDiskUsage.Volumes.Items //nolint: staticcheck,SA1019: v.Volumes is deprecated: kept to maintain backwards compatibility with API < v1.52, use [VolumesDiskUsage.Items] instead.
+			v.Volumes = nonNilSlice(systemDiskUsage.Volumes.Items) //nolint: staticcheck,SA1019: v.Volumes is deprecated: kept to maintain backwards compatibility with API < v1.52, use [VolumesDiskUsage.Items] instead.
 		} else if verbose {
 			v.VolumeUsage.Items = systemDiskUsage.Volumes.Items
 		}
@@ -287,7 +282,7 @@ func (s *systemRouter) getDiskUsage(ctx context.Context, w http.ResponseWriter,
 		v.BuildCacheUsage.Reclaimable = reclaimable
 
 		if legacyFields {
-			v.BuildCache = buildCache //nolint: staticcheck,SA1019: v.BuildCache is deprecated: kept to maintain backwards compatibility with API < v1.52, use [BuildCacheDiskUsage.Items] instead.
+			v.BuildCache = nonNilSlice(buildCache) //nolint: staticcheck,SA1019: v.BuildCache is deprecated: kept to maintain backwards compatibility with API < v1.52, use [BuildCacheDiskUsage.Items] instead.
 		} else if verbose {
 			v.BuildCacheUsage.Items = buildCache
 		}
@@ -295,6 +290,15 @@ func (s *systemRouter) getDiskUsage(ctx context.Context, w http.ResponseWriter,
 	return httputils.WriteJSON(w, http.StatusOK, v)
 }
 
+// nonNilSlice is used for the legacy fields, which are either omitted
+// entirely, or (if set), must return an empty slice in the response.
+func nonNilSlice[T any](s []T) []T {
+	if s == nil {
+		return []T{}
+	}
+	return s
+}
+
 type invalidRequestError struct {
 	Err error
 }

integration/system/disk_usage_test.go

@@ -5,10 +5,6 @@ import (
 	"testing"
 
 	"github.com/google/go-cmp/cmp/cmpopts"
-	"github.com/moby/moby/api/types/build"
-	containertypes "github.com/moby/moby/api/types/container"
-	"github.com/moby/moby/api/types/image"
-	"github.com/moby/moby/api/types/volume"
 	"github.com/moby/moby/client"
 	"github.com/moby/moby/v2/integration/internal/container"
 	"github.com/moby/moby/v2/internal/testutil"
@@ -56,19 +52,12 @@ func TestDiskUsage(t *testing.T) {
 				}
 
 				assert.DeepEqual(t, du, client.DiskUsageResult{
-					Containers: client.ContainersDiskUsage{
-						Items: []containertypes.Summary{},
-					},
+					Containers: client.ContainersDiskUsage{},
 					Images: client.ImagesDiskUsage{
 						TotalSize: expectedLayersSize,
-						Items:     []image.Summary{},
-					},
-					BuildCache: client.BuildCacheDiskUsage{
-						Items: []build.CacheRecord{},
-					},
-					Volumes: client.VolumesDiskUsage{
-						Items: []volume.Volume{},
 					},
+					BuildCache: client.BuildCacheDiskUsage{},
+					Volumes:    client.VolumesDiskUsage{},
 				})
 				return du
 			},
@@ -155,9 +144,9 @@ func TestDiskUsage(t *testing.T) {
 					},
 					expected: client.DiskUsageResult{
 						Containers: stepDU.Containers,
-						Images:     client.ImagesDiskUsage{Items: []image.Summary{}},
-						BuildCache: client.BuildCacheDiskUsage{Items: []build.CacheRecord{}},
-						Volumes:    client.VolumesDiskUsage{Items: []volume.Volume{}},
+						Images:     client.ImagesDiskUsage{},
+						BuildCache: client.BuildCacheDiskUsage{},
+						Volumes:    client.VolumesDiskUsage{},
 					},
 				},
 				{
@@ -167,10 +156,10 @@ func TestDiskUsage(t *testing.T) {
 						Verbose: true,
 					},
 					expected: client.DiskUsageResult{
-						Containers: client.ContainersDiskUsage{Items: []containertypes.Summary{}},
+						Containers: client.ContainersDiskUsage{},
 						Images:     stepDU.Images,
-						BuildCache: client.BuildCacheDiskUsage{Items: []build.CacheRecord{}},
-						Volumes:    client.VolumesDiskUsage{Items: []volume.Volume{}},
+						BuildCache: client.BuildCacheDiskUsage{},
+						Volumes:    client.VolumesDiskUsage{},
 					},
 				},
 				{
@@ -180,9 +169,9 @@ func TestDiskUsage(t *testing.T) {
 						Verbose: true,
 					},
 					expected: client.DiskUsageResult{
-						Containers: client.ContainersDiskUsage{Items: []containertypes.Summary{}},
-						Images:     client.ImagesDiskUsage{Items: []image.Summary{}},
-						BuildCache: client.BuildCacheDiskUsage{Items: []build.CacheRecord{}},
+						Containers: client.ContainersDiskUsage{},
+						Images:     client.ImagesDiskUsage{},
+						BuildCache: client.BuildCacheDiskUsage{},
 						Volumes:    stepDU.Volumes,
 					},
 				},
@@ -193,10 +182,10 @@ func TestDiskUsage(t *testing.T) {
 						Verbose:    true,
 					},
 					expected: client.DiskUsageResult{
-						Containers: client.ContainersDiskUsage{Items: []containertypes.Summary{}},
-						Images:     client.ImagesDiskUsage{Items: []image.Summary{}},
+						Containers: client.ContainersDiskUsage{},
+						Images:     client.ImagesDiskUsage{},
 						BuildCache: stepDU.BuildCache,
-						Volumes:    client.VolumesDiskUsage{Items: []volume.Volume{}},
+						Volumes:    client.VolumesDiskUsage{},
 					},
 				},
 				{
@@ -208,8 +197,8 @@ func TestDiskUsage(t *testing.T) {
 					},
 					expected: client.DiskUsageResult{
 						Containers: stepDU.Containers,
-						Images:     client.ImagesDiskUsage{Items: []image.Summary{}},
-						BuildCache: client.BuildCacheDiskUsage{Items: []build.CacheRecord{}},
+						Images:     client.ImagesDiskUsage{},
+						BuildCache: client.BuildCacheDiskUsage{},
 						Volumes:    stepDU.Volumes,
 					},
 				},
@@ -221,10 +210,10 @@ func TestDiskUsage(t *testing.T) {
 						Verbose:    true,
 					},
 					expected: client.DiskUsageResult{
-						Containers: client.ContainersDiskUsage{Items: []containertypes.Summary{}},
+						Containers: client.ContainersDiskUsage{},
 						Images:     stepDU.Images,
 						BuildCache: stepDU.BuildCache,
-						Volumes:    client.VolumesDiskUsage{Items: []volume.Volume{}},
+						Volumes:    client.VolumesDiskUsage{},
 					},
 				},
 				{
@@ -237,9 +226,7 @@ func TestDiskUsage(t *testing.T) {
 					},
 					expected: client.DiskUsageResult{
 						Containers: stepDU.Containers,
-						Images: client.ImagesDiskUsage{
-							Items: []image.Summary{},
-						},
+						Images:     client.ImagesDiskUsage{},
 						BuildCache: stepDU.BuildCache,
 						Volumes:    stepDU.Volumes,
 					},
@@ -253,9 +240,7 @@ func TestDiskUsage(t *testing.T) {
 						Verbose:    true,
 					},
 					expected: client.DiskUsageResult{
-						Containers: client.ContainersDiskUsage{
-							Items: []containertypes.Summary{},
-						},
+						Containers: client.ContainersDiskUsage{},
 						Images:     stepDU.Images,
 						BuildCache: stepDU.BuildCache,
 						Volumes:    stepDU.Volumes,
@@ -272,10 +257,8 @@ func TestDiskUsage(t *testing.T) {
 					expected: client.DiskUsageResult{
 						Containers: stepDU.Containers,
 						Images:     stepDU.Images,
-						BuildCache: client.BuildCacheDiskUsage{
-							Items: []build.CacheRecord{},
-						},
-						Volumes: stepDU.Volumes,
+						BuildCache: client.BuildCacheDiskUsage{},
+						Volumes:    stepDU.Volumes,
 					},
 				},
 				{

internal/sliceutil/sliceutil.go

@@ -1,5 +1,18 @@
 package sliceutil
 
+func Deref[T any](slice []*T) []T {
+	if slice == nil {
+		return nil
+	}
+	out := make([]T, 0, len(slice))
+	for _, p := range slice {
+		if p != nil {
+			out = append(out, *p)
+		}
+	}
+	return out
+}
+
 func Dedup[T comparable](slice []T) []T {
 	keys := make(map[T]struct{})
 	out := make([]T, 0, len(slice))

vendor/github.com/moby/moby/api/types/build/disk_usage.go

@@ -17,7 +17,7 @@ type DiskUsage struct {
 
 	// List of build cache records.
 	//
-	Items []*CacheRecord `json:"Items,omitempty"`
+	Items []CacheRecord `json:"Items,omitempty"`
 
 	// Disk space that can be reclaimed by removing inactive build cache records.
 	//

vendor/github.com/moby/moby/api/types/container/disk_usage.go

@@ -17,7 +17,7 @@ type DiskUsage struct {
 
 	// List of container summaries.
 	//
-	Items []*Summary `json:"Items,omitempty"`
+	Items []Summary `json:"Items,omitempty"`
 
 	// Disk space that can be reclaimed by removing inactive containers.
 	//

vendor/github.com/moby/moby/api/types/image/disk_usage.go

@@ -17,7 +17,7 @@ type DiskUsage struct {
 
 	// List of image summaries.
 	//
-	Items []*Summary `json:"Items,omitempty"`
+	Items []Summary `json:"Items,omitempty"`
 
 	// Disk space that can be reclaimed by removing unused images.
 	//

vendor/github.com/moby/moby/api/types/system/disk_usage.go

@@ -37,14 +37,14 @@ type LegacyDiskUsage struct {
 	LayersSize int64 `json:"LayersSize,omitempty"`
 
 	// Deprecated: kept to maintain backwards compatibility with API < v1.52, use [ImagesDiskUsage.Items] instead.
-	Images []*image.Summary `json:"Images,omitempty"`
+	Images []image.Summary `json:"Images,omitzero"`
 
 	// Deprecated: kept to maintain backwards compatibility with API < v1.52, use [ContainersDiskUsage.Items] instead.
-	Containers []*container.Summary `json:"Containers,omitempty"`
+	Containers []container.Summary `json:"Containers,omitzero"`
 
 	// Deprecated: kept to maintain backwards compatibility with API < v1.52, use [VolumesDiskUsage.Items] instead.
-	Volumes []*volume.Volume `json:"Volumes,omitempty"`
+	Volumes []volume.Volume `json:"Volumes,omitzero"`
 
 	// Deprecated: kept to maintain backwards compatibility with API < v1.52, use [BuildCacheDiskUsage.Items] instead.
-	BuildCache []*build.CacheRecord `json:"BuildCache,omitempty"`
+	BuildCache []build.CacheRecord `json:"BuildCache,omitzero"`
 }

vendor/github.com/moby/moby/api/types/volume/disk_usage.go

@@ -17,7 +17,7 @@ type DiskUsage struct {
 
 	// List of volumes.
 	//
-	Items []*Volume `json:"Items,omitempty"`
+	Items []Volume `json:"Items,omitempty"`
 
 	// Disk space that can be reclaimed by removing inactive volumes.
 	//

vendor/github.com/moby/moby/client/system_disk_usage.go

@@ -5,12 +5,15 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/url"
+	"slices"
+	"strings"
 
 	"github.com/moby/moby/api/types/build"
 	"github.com/moby/moby/api/types/container"
 	"github.com/moby/moby/api/types/image"
 	"github.com/moby/moby/api/types/system"
 	"github.com/moby/moby/api/types/volume"
+	"github.com/moby/moby/client/pkg/versions"
 )
 
 // DiskUsageOptions holds parameters for [Client.DiskUsage] operations.
@@ -151,103 +154,166 @@ func (cli *Client) DiskUsage(ctx context.Context, options DiskUsageOptions) (Dis
 		return DiskUsageResult{}, fmt.Errorf("Error retrieving disk usage: %v", err)
 	}
 
-	var (
-		r              DiskUsageResult
-		imagesFrom     = []*image.Summary{}
-		containersFrom = []*container.Summary{}
-		volumesFrom    = []*volume.Volume{}
-		buildCacheFrom = []*build.CacheRecord{}
-	)
+	// Generate result from a legacy response.
+	if versions.LessThan(cli.version, "1.52") {
+		return diskUsageResultFromLegacyAPI(&du), nil
+	}
 
-	if du.ImageUsage != nil {
+	var r DiskUsageResult
+	if idu := du.ImageUsage; idu != nil {
 		r.Images = ImagesDiskUsage{
-			ActiveImages: du.ImageUsage.ActiveImages,
-			Reclaimable:  du.ImageUsage.Reclaimable,
-			TotalImages:  du.ImageUsage.TotalImages,
-			TotalSize:    du.ImageUsage.TotalSize,
+			ActiveImages: idu.ActiveImages,
+			Reclaimable:  idu.Reclaimable,
+			TotalImages:  idu.TotalImages,
+			TotalSize:    idu.TotalSize,
 		}
 
 		if options.Verbose {
-			imagesFrom = du.ImageUsage.Items
-		}
-	} else {
-		// Fallback for legacy response.
-		r.Images = ImagesDiskUsage{
-			TotalSize: du.LayersSize,
-		}
-
-		if du.Images != nil && options.Verbose {
-			imagesFrom = du.Images
+			r.Images.Items = slices.Clone(idu.Items)
 		}
 	}
 
-	r.Images.Items = make([]image.Summary, len(imagesFrom))
-	for i, ii := range imagesFrom {
-		r.Images.Items[i] = *ii
-	}
-
-	if du.ContainerUsage != nil {
+	if cdu := du.ContainerUsage; cdu != nil {
 		r.Containers = ContainersDiskUsage{
-			ActiveContainers: du.ContainerUsage.ActiveContainers,
-			Reclaimable:      du.ContainerUsage.Reclaimable,
-			TotalContainers:  du.ContainerUsage.TotalContainers,
-			TotalSize:        du.ContainerUsage.TotalSize,
+			ActiveContainers: cdu.ActiveContainers,
+			Reclaimable:      cdu.Reclaimable,
+			TotalContainers:  cdu.TotalContainers,
+			TotalSize:        cdu.TotalSize,
 		}
 
 		if options.Verbose {
-			containersFrom = du.ContainerUsage.Items
+			r.Containers.Items = slices.Clone(cdu.Items)
 		}
-	} else if du.Containers != nil && options.Verbose {
-		// Fallback for legacy response.
-		containersFrom = du.Containers
 	}
 
-	r.Containers.Items = make([]container.Summary, len(containersFrom))
-	for i, c := range containersFrom {
-		r.Containers.Items[i] = *c
-	}
-
-	if du.BuildCacheUsage != nil {
+	if bdu := du.BuildCacheUsage; bdu != nil {
 		r.BuildCache = BuildCacheDiskUsage{
-			ActiveBuildCacheRecords: du.BuildCacheUsage.ActiveBuildCacheRecords,
-			Reclaimable:             du.BuildCacheUsage.Reclaimable,
-			TotalBuildCacheRecords:  du.BuildCacheUsage.TotalBuildCacheRecords,
-			TotalSize:               du.BuildCacheUsage.TotalSize,
+			ActiveBuildCacheRecords: bdu.ActiveBuildCacheRecords,
+			Reclaimable:             bdu.Reclaimable,
+			TotalBuildCacheRecords:  bdu.TotalBuildCacheRecords,
+			TotalSize:               bdu.TotalSize,
 		}
 
 		if options.Verbose {
-			buildCacheFrom = du.BuildCacheUsage.Items
+			r.BuildCache.Items = slices.Clone(bdu.Items)
 		}
-	} else if du.BuildCache != nil && options.Verbose {
-		// Fallback for legacy response.
-		buildCacheFrom = du.BuildCache
 	}
 
-	r.BuildCache.Items = make([]build.CacheRecord, len(buildCacheFrom))
-	for i, b := range buildCacheFrom {
-		r.BuildCache.Items[i] = *b
-	}
-
-	if du.VolumeUsage != nil {
+	if vdu := du.VolumeUsage; vdu != nil {
 		r.Volumes = VolumesDiskUsage{
-			ActiveVolumes: du.VolumeUsage.ActiveVolumes,
-			Reclaimable:   du.VolumeUsage.Reclaimable,
-			TotalSize:     du.VolumeUsage.TotalSize,
-			TotalVolumes:  du.VolumeUsage.TotalVolumes,
+			ActiveVolumes: vdu.ActiveVolumes,
+			Reclaimable:   vdu.Reclaimable,
+			TotalVolumes:  vdu.TotalVolumes,
+			TotalSize:     vdu.TotalSize,
 		}
 
 		if options.Verbose {
-			volumesFrom = du.VolumeUsage.Items
+			r.Volumes.Items = slices.Clone(vdu.Items)
 		}
-	} else if du.Volumes != nil && options.Verbose {
-		// Fallback for legacy response.
-		volumesFrom = du.Volumes
-	}
-
-	r.Volumes.Items = make([]volume.Volume, len(volumesFrom))
-	for i, v := range volumesFrom {
-		r.Volumes.Items[i] = *v
 	}
 
 	return r, nil
 }
+
+func diskUsageResultFromLegacyAPI(du *system.DiskUsage) DiskUsageResult {
+	return DiskUsageResult{
+		Images:     imageDiskUsageFromLegacyAPI(du),
+		Containers: containerDiskUsageFromLegacyAPI(du),
+		BuildCache: buildCacheDiskUsageFromLegacyAPI(du),
+		Volumes:    volumeDiskUsageFromLegacyAPI(du),
+	}
+}
+
+func imageDiskUsageFromLegacyAPI(du *system.DiskUsage) ImagesDiskUsage {
+	idu := ImagesDiskUsage{
+		TotalSize:   du.LayersSize,
+		TotalImages: int64(len(du.Images)),
+		Items:       du.Images,
+	}
+
+	var used int64
+	for _, i := range idu.Items {
+		if i.Containers > 0 {
+			idu.ActiveImages++
+
+			if i.Size == -1 || i.SharedSize == -1 {
+				continue
+			}
+			used += (i.Size - i.SharedSize)
+		}
+	}
+
+	if idu.TotalImages > 0 {
+		idu.Reclaimable = idu.TotalSize - used
+	}
+
+	return idu
+}
+
+func containerDiskUsageFromLegacyAPI(du *system.DiskUsage) ContainersDiskUsage {
+	cdu := ContainersDiskUsage{
+		TotalContainers: int64(len(du.Containers)),
+		Items:           du.Containers,
+	}
+
+	var used int64
+	for _, c := range cdu.Items {
+		cdu.TotalSize += c.SizeRw
+		switch strings.ToLower(c.State) {
+		case "running", "paused", "restarting":
+			cdu.ActiveContainers++
+			used += c.SizeRw
+		}
+	}
+
+	cdu.Reclaimable = cdu.TotalSize - used
+	return cdu
+}
+
+func buildCacheDiskUsageFromLegacyAPI(du *system.DiskUsage) BuildCacheDiskUsage {
+	bdu := BuildCacheDiskUsage{
+		TotalBuildCacheRecords: int64(len(du.BuildCache)),
+		Items:                  du.BuildCache,
+	}
+
+	var used int64
+	for _, b := range du.BuildCache {
+		if !b.Shared {
+			bdu.TotalSize += b.Size
+		}
+
+		if b.InUse {
+			bdu.ActiveBuildCacheRecords++
+			if !b.Shared {
+				used += b.Size
+			}
+		}
+	}
+
+	bdu.Reclaimable = bdu.TotalSize - used
+	return bdu
+}
+
+func volumeDiskUsageFromLegacyAPI(du *system.DiskUsage) VolumesDiskUsage {
+	vdu := VolumesDiskUsage{
+		TotalVolumes: int64(len(du.Volumes)),
+		Items:        du.Volumes,
+	}
+
+	var used int64
+	for _, v := range vdu.Items {
+		// Ignore volumes with no usage data
+		if v.UsageData != nil {
+			if v.UsageData.RefCount > 0 {
+				vdu.ActiveVolumes++
+				used += v.UsageData.Size
+			}
+			if v.UsageData.Size > 0 {
+				vdu.TotalSize += v.UsageData.Size
+			}
+		}
+	}
+
+	vdu.Reclaimable = vdu.TotalSize - used
+	return vdu
+}