xl: Fixes a bug in read quorum ListFiles() (#1412)

Fixes a bug in #1406

xl-v1.go

@@ -293,48 +293,44 @@ func (xl XL) StatVol(volume string) (volInfo VolInfo, err error) {
 // isLeafDirectory - check if a given path is leaf directory. i.e
 // there are no more directories inside it. Erasure code backend
 // format it means that the parent directory is the actual object name.
-func (xl XL) isLeafDirectory(volume, leafPath string) (isLeaf bool) {
-	var allFileInfos []FileInfo
+func isLeafDirectory(disk StorageAPI, volume, leafPath string) (isLeaf bool) {
 	var markerPath string
+	var xlListCount = 1000 // Count page.
 	for {
-		fileInfos, eof, err := xl.storageDisks[0].ListFiles(volume, leafPath, markerPath, false, 1000)
+		fileInfos, eof, err := disk.ListFiles(volume, leafPath, markerPath, false, xlListCount)
 		if err != nil {
 			log.WithFields(logrus.Fields{
 				"volume":     volume,
 				"leafPath":   leafPath,
 				"markerPath": markerPath,
 				"recursive":  false,
-				"count":      1000,
+				"count":      xlListCount,
 			}).Errorf("ListFiles failed with %s", err)
 			break
 		}
-		allFileInfos = append(allFileInfos, fileInfos...)
+		for _, fileInfo := range fileInfos {
+			if fileInfo.Mode.IsDir() {
+				// Directory found, not a leaf directory, return right here.
+				return false
+			}
+		}
 		if eof {
 			break
 		}
 		// MarkerPath to get the next set of files.
-		markerPath = allFileInfos[len(allFileInfos)-1].Name
-	}
-	for _, fileInfo := range allFileInfos {
-		if fileInfo.Mode.IsDir() {
-			// Directory found, not a leaf directory, return right here.
-			isLeaf = false
-			return isLeaf
-		}
+		markerPath = fileInfos[len(fileInfos)-1].Name
 	}
 	// Exhausted all the entries, no directories found must be leaf
 	// return right here.
-	isLeaf = true
-	return isLeaf
+	return true
 }
 
 // extractMetadata - extract file metadata.
-func (xl XL) extractMetadata(volume, path string) (fileMetadata, error) {
+func extractMetadata(disk StorageAPI, volume, path string) (fileMetadata, error) {
 	metadataFilePath := slashpath.Join(path, metadataFile)
 	// We are not going to read partial data from metadata file,
 	// read the whole file always.
 	offset := int64(0)
-	disk := xl.storageDisks[0]
 	metadataReader, err := disk.ReadFile(volume, metadataFilePath, offset)
 	if err != nil {
 		log.WithFields(logrus.Fields{
@@ -360,12 +356,12 @@ func (xl XL) extractMetadata(volume, path string) (fileMetadata, error) {
 }
 
 // Extract file info from paths.
-func (xl XL) extractFileInfo(volume, path string) (FileInfo, error) {
+func extractFileInfo(disk StorageAPI, volume, path string) (FileInfo, error) {
 	fileInfo := FileInfo{}
 	fileInfo.Volume = volume
 	fileInfo.Name = path
 
-	metadata, err := xl.extractMetadata(volume, path)
+	metadata, err := extractMetadata(disk, volume, path)
 	if err != nil {
 		log.WithFields(logrus.Fields{
 			"volume": volume,
@@ -422,7 +418,7 @@ func (xl XL) ListFiles(volume, prefix, marker string, recursive bool, count int)
 	var firstErr error
 
 	for _, disk := range xl.storageDisks {
-		if filesInfo, eof, err = xl.listFiles(disk, volume, prefix, marker, recursive, count); err == nil {
+		if filesInfo, eof, err = listFiles(disk, volume, prefix, marker, recursive, count); err == nil {
 			// we need to return first successful result
 			if firstFilesInfo == nil {
 				firstFilesInfo = filesInfo
@@ -454,11 +450,11 @@ func (xl XL) ListFiles(volume, prefix, marker string, recursive bool, count int)
 	return nil, false, errReadQuorum
 }
 
-func (xl XL) listFiles(disk StorageAPI, volume, prefix, marker string, recursive bool, count int) (filesInfo []FileInfo, eof bool, err error) {
+func listFiles(disk StorageAPI, volume, prefix, marker string, recursive bool, count int) (filesInfo []FileInfo, eof bool, err error) {
 	var fsFilesInfo []FileInfo
 	var markerPath = marker
 	if marker != "" {
-		isLeaf := xl.isLeafDirectory(volume, retainSlash(marker))
+		isLeaf := isLeafDirectory(disk, volume, retainSlash(marker))
 		if isLeaf {
 			// For leaf for now we just point to the first block, make it
 			// dynamic in future based on the availability of storage disks.
@@ -466,6 +462,8 @@ func (xl XL) listFiles(disk StorageAPI, volume, prefix, marker string, recursive
 		}
 	}
 
+	// Loop and capture the proper fileInfos, requires extraction and
+	// separation of XL related metadata information.
 	for {
 		fsFilesInfo, eof, err = disk.ListFiles(volume, prefix, markerPath, recursive, count)
 		if err != nil {
@@ -486,13 +484,13 @@ func (xl XL) listFiles(disk StorageAPI, volume, prefix, marker string, recursive
 			var fileInfo FileInfo
 			var isLeaf bool
 			if fsFileInfo.Mode.IsDir() {
-				isLeaf = xl.isLeafDirectory(volume, fsFileInfo.Name)
+				isLeaf = isLeafDirectory(disk, volume, fsFileInfo.Name)
 			}
 			if isLeaf || !fsFileInfo.Mode.IsDir() {
 				// Extract the parent of leaf directory or file to get the
 				// actual name.
 				path := slashpath.Dir(fsFileInfo.Name)
-				fileInfo, err = xl.extractFileInfo(volume, path)
+				fileInfo, err = extractFileInfo(disk, volume, path)
 				if err != nil {
 					log.WithFields(logrus.Fields{
 						"volume": volume,
@@ -516,10 +514,9 @@ func (xl XL) listFiles(disk StorageAPI, volume, prefix, marker string, recursive
 				break
 			}
 		}
-		lenFsFilesInfo := len(fsFilesInfo)
-		if lenFsFilesInfo != 0 {
+		if len(fsFilesInfo) > 0 {
 			// markerPath for the next disk.ListFiles() iteration.
-			markerPath = fsFilesInfo[lenFsFilesInfo-1].Name
+			markerPath = fsFilesInfo[len(fsFilesInfo)-1].Name
 		}
 		if count == 0 && recursive && !strings.HasSuffix(markerPath, metadataFile) {
 			// If last entry is not part.json then loop once more to check if we