Rely on contaienrd's GC for cleanup of temporary content

Signed-off-by: Kohei Tokunaga <[email protected]>

nativeconverter/zstdchunked/zstdchunked.go

@@ -20,7 +20,6 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"sync"
 
 	"github.com/containerd/containerd/v2/core/content"
 	"github.com/containerd/containerd/v2/core/images"
@@ -38,15 +37,6 @@ import (
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
-type unMap struct {
-	mu sync.Mutex
-}
-
-var (
-	mu            sync.Mutex
-	uncompressMap = map[digest.Digest]*unMap{}
-)
-
 type zstdCompression struct {
 	*zstdchunked.Decompressor
 	*zstdchunked.Compressor
@@ -111,14 +101,6 @@ func LayerConvertFuncWithCompressionLevel(compressionLevel zstd.EncoderLevel, op
 		uncompressedDesc := &desc
 		// We need to uncompress the archive first
 		if !uncompress.IsUncompressedType(desc.MediaType) {
-			mu.Lock()
-			if _, ok := uncompressMap[desc.Digest]; !ok {
-				uncompressMap[desc.Digest] = &unMap{}
-			}
-			uncompressMap[desc.Digest].mu.Lock()
-			mu.Unlock()
-			defer uncompressMap[desc.Digest].mu.Unlock()
-
 			var err error
 			uncompressedDesc, err = uncompress.LayerConvertFunc(ctx, cs, desc)
 			if err != nil {
@@ -127,11 +109,6 @@ func LayerConvertFuncWithCompressionLevel(compressionLevel zstd.EncoderLevel, op
 			if uncompressedDesc == nil {
 				return nil, fmt.Errorf("unexpectedly got the same blob after compression (%s, %q)", desc.Digest, desc.MediaType)
 			}
-			defer func() {
-				if err := cs.Delete(ctx, uncompressedDesc.Digest); err != nil {
-					log.G(ctx).WithError(err).WithField("uncompressedDesc", uncompressedDesc).Warn("failed to remove tmp uncompressed layer")
-				}
-			}()
 			log.G(ctx).Debugf("zstdchunked: uncompressed %s into %s", desc.Digest, uncompressedDesc.Digest)
 		}