Fence installation transaction durability (T-613)

core/installer/extractor.go

@@ -35,7 +35,8 @@ var (
 
 // Extractor writes only payload/ contents from a pre-verified package ZIP.
 type Extractor struct {
-	limits Limits
+	limits     Limits
+	durability durabilityFence
 }
 
 type ExtractResult struct {
@@ -56,7 +57,7 @@ func NewExtractor(limits Limits) (Extractor, error) {
 	if err := limits.validate(); err != nil {
 		return Extractor{}, err
 	}
-	return Extractor{limits: limits}, nil
+	return Extractor{limits: limits, durability: defaultDurability()}, nil
 }
 
 // ExtractFile requires expectedPackageSize from the verified Catalog package.
@@ -88,6 +89,7 @@ func (extractor Extractor) extract(
 	if err := extractor.limits.validate(); err != nil {
 		return ExtractResult{}, err
 	}
+	fence := effectiveDurability(extractor.durability)
 	normalizedEntrypoint, err := normalizeEntrypoint(entrypoint)
 	if err != nil {
 		return ExtractResult{}, err
@@ -160,21 +162,21 @@ func (extractor Extractor) extract(
 			readLimit++
 		}
 		copied, copyErr := io.Copy(output, io.LimitReader(source, readLimit))
-		closeOutputErr := output.Close()
 		closeSourceErr := source.Close()
 		if copyErr != nil {
+			_ = output.Close()
 			return ExtractResult{}, fmt.Errorf("%w: read %s: %v", ErrArchiveCorrupt, entry.archivePath, copyErr)
 		}
-		if closeOutputErr != nil {
-			return ExtractResult{}, fmt.Errorf("close staging file: %w", closeOutputErr)
-		}
 		if closeSourceErr != nil {
+			_ = output.Close()
 			return ExtractResult{}, fmt.Errorf("%w: close %s: %v", ErrArchiveCorrupt, entry.archivePath, closeSourceErr)
 		}
 		if copied > remaining {
+			_ = output.Close()
 			return ExtractResult{}, ErrExpandedTooLarge
 		}
 		if uint64(copied) != entry.file.UncompressedSize64 {
+			_ = output.Close()
 			return ExtractResult{}, fmt.Errorf(
 				"%w: %s expanded to %d bytes, header declares %d",
 				ErrArchiveCorrupt,
@@ -183,9 +185,19 @@ func (extractor Extractor) extract(
 				entry.file.UncompressedSize64,
 			)
 		}
+		if err := syncFileWithFence(fence, output, "staging payload"); err != nil {
+			_ = output.Close()
+			return ExtractResult{}, err
+		}
+		if err := output.Close(); err != nil {
+			return ExtractResult{}, fmt.Errorf("close staging file: %w", err)
+		}
 		written += copied
 		result.Files++
 	}
+	if err := syncStagingTree(fence, destinationRoot); err != nil {
+		return ExtractResult{}, err
+	}
 
 	result.Bytes = written
 	result.EntrypointPath = entrypointPath