fix: ListObjectVersions should return ordered Version & DeleteMarker (#9959)

The S3 specification says that versions are ordered in the response of
list object versions.

mc snapshot needs this to know which version comes first especially when
two versions have the same exact last-modified field.

cmd/api-response.go

@@ -81,7 +81,6 @@ type ListVersionsResponse struct {
 
 	CommonPrefixes []CommonPrefix
 	Versions       []ObjectVersion
-	DeleteMarkers  []DeletedVersion
 
 	// Encoding type used to encode object keys in the response.
 	EncodingType string `xml:"EncodingType,omitempty"`
@@ -236,24 +235,23 @@ type Bucket struct {
 
 // ObjectVersion container for object version metadata
 type ObjectVersion struct {
-	XMLName xml.Name `xml:"http://s3.amazonaws.com/doc/2006-03-01/ Version" json:"-"`
 	Object
 	IsLatest  bool
 	VersionID string `xml:"VersionId"`
-}
-
-// DeletedVersion container for the delete object version metadata.
-type DeletedVersion struct {
-	XMLName xml.Name `xml:"http://s3.amazonaws.com/doc/2006-03-01/ DeleteMarker" json:"-"`
 
-	IsLatest     bool
-	Key          string
-	LastModified string // time string of format "2006-01-02T15:04:05.000Z"
+	isDeleteMarker bool
+}
 
-	// Owner of the object.
-	Owner Owner
+// MarshalXML - marshal ObjectVersion
+func (o ObjectVersion) MarshalXML(e *xml.Encoder, start xml.StartElement) error {
+	if o.isDeleteMarker {
+		start.Name.Local = "DeleteMarker"
+	} else {
+		start.Name.Local = "Version"
+	}
 
-	VersionID string `xml:"VersionId"`
+	type objectVersionWrapper ObjectVersion
+	return e.EncodeElement(objectVersionWrapper(o), start)
 }
 
 // StringMap is a map[string]string.
@@ -431,7 +429,6 @@ func generateListBucketsResponse(buckets []BucketInfo) ListBucketsResponse {
 // generates an ListBucketVersions response for the said bucket with other enumerated options.
 func generateListVersionsResponse(bucket, prefix, marker, versionIDMarker, delimiter, encodingType string, maxKeys int, resp ListObjectVersionsInfo) ListVersionsResponse {
 	var versions []ObjectVersion
-	var deletedVersions []DeletedVersion
 	var prefixes []CommonPrefix
 	var owner = Owner{}
 	var data = ListVersionsResponse{}
@@ -459,23 +456,12 @@ func generateListVersionsResponse(bucket, prefix, marker, versionIDMarker, delim
 			content.VersionID = nullVersionID
 		}
 		content.IsLatest = object.IsLatest
+		content.isDeleteMarker = object.DeleteMarker
 		versions = append(versions, content)
 	}
 
-	for _, deleted := range resp.DeleteObjects {
-		var dv = DeletedVersion{
-			Key:          s3EncodeName(deleted.Name, encodingType),
-			Owner:        owner,
-			LastModified: deleted.ModTime.UTC().Format(iso8601TimeFormat),
-			VersionID:    deleted.VersionID,
-			IsLatest:     deleted.IsLatest,
-		}
-		deletedVersions = append(deletedVersions, dv)
-	}
-
 	data.Name = bucket
 	data.Versions = versions
-	data.DeleteMarkers = deletedVersions
 	data.EncodingType = encodingType
 	data.Prefix = s3EncodeName(prefix, encodingType)
 	data.KeyMarker = s3EncodeName(marker, encodingType)

cmd/erasure-sets.go

@@ -1534,9 +1534,6 @@ func (s *erasureSets) Walk(ctx context.Context, bucket, prefix string, results c
 				for _, version := range entry.Versions {
 					results <- version.ToObjectInfo(bucket, version.Name)
 				}
-				for _, deleted := range entry.Deleted {
-					results <- deleted.ToObjectInfo(bucket, deleted.Name)
-				}
 			}
 			// skip entries which do not have quorum
 		}

cmd/erasure-zones.go

@@ -1322,16 +1322,6 @@ func (z *erasureZones) listObjectVersions(ctx context.Context, bucket, prefix, m
 			}
 			loi.Objects = append(loi.Objects, objInfo)
 		}
-		for _, deleted := range entry.Deleted {
-			loi.DeleteObjects = append(loi.DeleteObjects, DeletedObjectInfo{
-				Bucket:    bucket,
-				Name:      entry.Name,
-				VersionID: deleted.VersionID,
-				ModTime:   deleted.ModTime,
-				IsLatest:  deleted.IsLatest,
-			})
-		}
-
 	}
 	if loi.IsTruncated {
 		for i, zone := range z.zones {
@@ -1848,9 +1838,6 @@ func (z *erasureZones) Walk(ctx context.Context, bucket, prefix string, results
 				for _, version := range entry.Versions {
 					results <- version.ToObjectInfo(bucket, version.Name)
 				}
-				for _, deleted := range entry.Deleted {
-					results <- deleted.ToObjectInfo(bucket, deleted.Name)
-				}
 			}
 
 			// skip entries which do not have quorum

cmd/object-api-datatypes.go

@@ -368,9 +368,6 @@ type ListObjectVersionsInfo struct {
 	// List of objects info for this request.
 	Objects []ObjectInfo
 
-	// List of deleted objects for this request.
-	DeleteObjects []DeletedObjectInfo
-
 	// List of prefixes for this request.
 	Prefixes []string
 }

cmd/storage-datatypes.go

@@ -57,7 +57,6 @@ type FileInfoVersions struct {
 	LatestModTime time.Time
 
 	Versions []FileInfo
-	Deleted  []FileInfo
 }
 
 // FileInfo - represents file stat information.

cmd/xl-storage-format-utils.go

@@ -26,7 +26,7 @@ func getFileInfoVersions(xlMetaBuf []byte, volume, path string) (FileInfoVersion
 		if err := xlMeta.Load(xlMetaBuf); err != nil {
 			return FileInfoVersions{}, err
 		}
-		versions, deletedVersions, latestModTime, err := xlMeta.ListVersions(volume, path)
+		versions, latestModTime, err := xlMeta.ListVersions(volume, path)
 		if err != nil {
 			return FileInfoVersions{}, err
 		}
@@ -34,7 +34,6 @@ func getFileInfoVersions(xlMetaBuf []byte, volume, path string) (FileInfoVersion
 			Volume:        volume,
 			Name:          path,
 			Versions:      versions,
-			Deleted:       deletedVersions,
 			LatestModTime: latestModTime,
 		}, nil
 	}

cmd/xl-storage-format-v2.go

@@ -473,12 +473,12 @@ func (z xlMetaV2) TotalSize() int64 {
 
 // ListVersions lists current versions, and current deleted
 // versions returns error for unexpected entries.
-func (z xlMetaV2) ListVersions(volume, path string) (versions []FileInfo, deleted []FileInfo, modTime time.Time, err error) {
+func (z xlMetaV2) ListVersions(volume, path string) (versions []FileInfo, modTime time.Time, err error) {
 	var latestModTime time.Time
 	var latestVersionID string
 	for _, version := range z.Versions {
 		if !version.Valid() {
-			return nil, nil, latestModTime, errFileCorrupt
+			return nil, latestModTime, errFileCorrupt
 		}
 		var fi FileInfo
 		switch version.Type {
@@ -492,7 +492,7 @@ func (z xlMetaV2) ListVersions(volume, path string) (versions []FileInfo, delete
 			continue
 		}
 		if err != nil {
-			return nil, nil, latestModTime, err
+			return nil, latestModTime, err
 		}
 		if fi.ModTime.After(latestModTime) {
 			latestModTime = fi.ModTime
@@ -501,24 +501,11 @@ func (z xlMetaV2) ListVersions(volume, path string) (versions []FileInfo, delete
 		switch version.Type {
 		case LegacyType:
 			fallthrough
-		case ObjectType:
+		case ObjectType, DeleteType:
 			versions = append(versions, fi)
-		case DeleteType:
-			deleted = append(deleted, fi)
-
 		}
 	}
 
-	// Since we can never have duplicate versions the versionID
-	// if it matches first with deleted markers then we are sure
-	// that actual versions wouldn't be latest, so we can return
-	// early if we find the version in delete markers.
-	for i := range deleted {
-		if deleted[i].VersionID == latestVersionID {
-			deleted[i].IsLatest = true
-			return versions, deleted, latestModTime, nil
-		}
-	}
 	// We didn't find the version in delete markers so latest version
 	// is indeed one of the actual version of the object with data.
 	for i := range versions {
@@ -528,7 +515,8 @@ func (z xlMetaV2) ListVersions(volume, path string) (versions []FileInfo, delete
 		versions[i].IsLatest = true
 		break
 	}
-	return versions, deleted, latestModTime, nil
+
+	return versions, latestModTime, nil
 }
 
 // ToFileInfo converts xlMetaV2 into a common FileInfo datastructure

cmd/xl-storage.go

@@ -409,12 +409,9 @@ func (s *xlStorage) CrawlAndGetDataUsage(ctx context.Context, cache dataUsageCac
 		var totalSize int64
 		for _, version := range fivs.Versions {
 			size := item.applyActions(ctx, objAPI, actionMeta{oi: version.ToObjectInfo(item.bucket, item.objectPath())})
-			totalSize += size
-		}
-
-		// Delete markers have no size, nothing to do here.
-		for _, deleted := range fivs.Deleted {
-			item.applyActions(ctx, objAPI, actionMeta{oi: deleted.ToObjectInfo(item.bucket, item.objectPath())})
+			if !version.Deleted {
+				totalSize += size
+			}
 		}
 
 		return totalSize, nil