Remove inline data hack (#12946)

move the code down to the storage layer,
this logic decouples the inline data from the 
size parameter making it flexible and future
proof.

cmd/erasure-object.go

@@ -256,26 +256,6 @@ func (er erasureObjects) getObjectWithFileInfo(ctx context.Context, bucket, obje
 		return toObjectErr(err, bucket, object)
 	}
 
-	// This hack is needed to avoid a bug found when overwriting
-	// the inline data object with a un-inlined version, for the
-	// time being we need this as we have released inline-data
-	// version already and this bug is already present in newer
-	// releases.
-	//
-	// This mainly happens with objects < smallFileThreshold when
-	// they are overwritten with un-inlined objects >= smallFileThreshold,
-	// due to a bug in RenameData() the fi.Data is not niled leading to
-	// GetObject thinking that fi.Data is valid while fi.Size has
-	// changed already.
-	if fi.InlineData() {
-		shardFileSize := erasure.ShardFileSize(fi.Size)
-		if shardFileSize >= 0 && shardFileSize >= smallFileThreshold {
-			for i := range metaArr {
-				metaArr[i].Data = nil
-			}
-		}
-	}
-
 	var healOnce sync.Once
 
 	// once we have obtained a common FileInfo i.e latest, we should stick

cmd/storage-datatypes.go

@@ -190,7 +190,10 @@ func (fi FileInfo) InlineData() bool {
 }
 
 // SetInlineData marks object (version) as inline.
-func (fi FileInfo) SetInlineData() {
+func (fi *FileInfo) SetInlineData() {
+	if fi.Metadata == nil {
+		fi.Metadata = make(map[string]string, 1)
+	}
 	fi.Metadata[ReservedMetadataPrefixLower+"inline-data"] = "true"
 }
 

cmd/xl-storage-format-v2.go

@@ -253,7 +253,7 @@ type xlMetaV2 struct {
 //msgp:ignore xlMetaInlineData
 type xlMetaInlineData []byte
 
-// xlMetaInlineDataVer indicates the vesrion of the inline data structure.
+// xlMetaInlineDataVer indicates the version of the inline data structure.
 const xlMetaInlineDataVer = 1
 
 // versionOK returns whether the version is ok.

cmd/xl-storage.go

@@ -1130,12 +1130,29 @@ func (s *xlStorage) ReadVersion(ctx context.Context, volume, path, versionID str
 
 	if readData {
 		if len(fi.Data) > 0 || fi.Size == 0 {
-			if len(fi.Data) > 0 {
-				if !fi.InlineData() {
-					fi.SetInlineData()
-				}
+			if fi.InlineData() {
+				// If written with header we are fine.
+				return fi, nil
 			}
-			return fi, nil
+			if fi.Size == 0 || !(fi.VersionID != "" && fi.VersionID != nullVersionID) {
+				// If versioned we have no conflicts.
+				fi.SetInlineData()
+				return fi, nil
+			}
+
+			// For overwritten objects without header we might have a conflict with
+			// data written later.
+			// Check the data path if there is a part with data.
+			partPath := fmt.Sprintf("part.%d", fi.Parts[0].Number)
+			dataPath := pathJoin(path, fi.DataDir, partPath)
+			_, err = s.StatInfoFile(ctx, volume, dataPath)
+			if err != nil {
+				// Set the inline header, our inlined data is fine.
+				fi.SetInlineData()
+				return fi, nil
+			}
+			// Data exists on disk, remove the version from metadata.
+			fi.Data = nil
 		}
 
 		// Reading data for small objects when