FS/ListMultipart: Fix FS list-multipart to work for unit test cases.

fs-v1-multipart.go

@@ -92,22 +92,16 @@ func (fs fsObjects) newMultipartUploadCommon(bucket string, object string, meta
 	return uploadID, nil
 }
 
-func isMultipartObject(storage StorageAPI, bucket, prefix string) bool {
+// Returns if the prefix is a multipart upload.
-	_, err := storage.StatFile(bucket, path.Join(prefix, fsMetaJSONFile))
+func (fs fsObjects) isMultipartUpload(bucket, prefix string) bool {
-	if err != nil {
+	_, err := fs.storage.StatFile(bucket, pathJoin(prefix, uploadsJSONFile))
-		if err == errFileNotFound {
+	return err == nil
-			return false
-		}
-		errorIf(err, "Unable to access "+path.Join(prefix, fsMetaJSONFile))
-		return false
-	}
-	return true
 }
 
 // listUploadsInfo - list all uploads info.
 func (fs fsObjects) listUploadsInfo(prefixPath string) (uploads []uploadInfo, err error) {
 	splitPrefixes := strings.SplitN(prefixPath, "/", 3)
-	uploadIDs, err := getUploadIDs(splitPrefixes[1], splitPrefixes[2], fs.storage)
+	uploadIDs, err := readUploadsJSON(splitPrefixes[1], splitPrefixes[2], fs.storage)
 	if err != nil {
 		if err == errFileNotFound {
 			return []uploadInfo{}, nil
@@ -118,96 +112,6 @@ func (fs fsObjects) listUploadsInfo(prefixPath string) (uploads []uploadInfo, er
 	return uploads, nil
 }
 
-// listMetaBucketMultipart - list all objects at a given prefix inside minioMetaBucket.
-func (fs fsObjects) listMetaBucketMultipart(prefixPath string, markerPath string, recursive bool, maxKeys int) (fileInfos []FileInfo, eof bool, err error) {
-	walker := fs.lookupTreeWalk(listParams{minioMetaBucket, recursive, markerPath, prefixPath})
-	if walker == nil {
-		walker = fs.startTreeWalk(minioMetaBucket, prefixPath, markerPath, recursive)
-	}
-
-	// newMaxKeys tracks the size of entries which are going to be
-	// returned back.
-	var newMaxKeys int
-
-	// Following loop gathers and filters out special files inside
-	// minio meta volume.
-	for {
-		walkResult, ok := <-walker.ch
-		if !ok {
-			// Closed channel.
-			eof = true
-			break
-		}
-		// For any walk error return right away.
-		if walkResult.err != nil {
-			// File not found or Disk not found is a valid case.
-			if walkResult.err == errFileNotFound || walkResult.err == errDiskNotFound {
-				return nil, true, nil
-			}
-			return nil, false, toObjectErr(walkResult.err, minioMetaBucket, prefixPath)
-		}
-		fileInfo := walkResult.fileInfo
-		var uploads []uploadInfo
-		if fileInfo.Mode.IsDir() {
-			// List all the entries if fi.Name is a leaf directory, if
-			// fi.Name is not a leaf directory then the resulting
-			// entries are empty.
-			uploads, err = fs.listUploadsInfo(fileInfo.Name)
-			if err != nil {
-				return nil, false, err
-			}
-		}
-		if len(uploads) > 0 {
-			for _, upload := range uploads {
-				fileInfos = append(fileInfos, FileInfo{
-					Name:    path.Join(fileInfo.Name, upload.UploadID),
-					ModTime: upload.Initiated,
-				})
-				newMaxKeys++
-				// If we have reached the maxKeys, it means we have listed
-				// everything that was requested.
-				if newMaxKeys == maxKeys {
-					break
-				}
-			}
-		} else {
-			// We reach here for a non-recursive case non-leaf entry
-			// OR recursive case with fi.Name.
-			if !fileInfo.Mode.IsDir() { // Do not skip non-recursive case directory entries.
-				// Validate if 'fi.Name' is incomplete multipart.
-				if !strings.HasSuffix(fileInfo.Name, fsMetaJSONFile) {
-					continue
-				}
-				fileInfo.Name = path.Dir(fileInfo.Name)
-			}
-			fileInfos = append(fileInfos, fileInfo)
-			newMaxKeys++
-			// If we have reached the maxKeys, it means we have listed
-			// everything that was requested.
-			if newMaxKeys == maxKeys {
-				break
-			}
-		}
-	}
-
-	if !eof && len(fileInfos) != 0 {
-		// EOF has not reached, hence save the walker channel to the map so that the walker go routine
-		// can continue from where it left off for the next list request.
-		lastFileInfo := fileInfos[len(fileInfos)-1]
-		markerPath = lastFileInfo.Name
-		fs.saveTreeWalk(listParams{minioMetaBucket, recursive, markerPath, prefixPath}, walker)
-	}
-
-	// Return entries here.
-	return fileInfos, eof, nil
-}
-
-// FIXME: Currently the code sorts based on keyName/upload-id which is
-// not correct based on the S3 specs. According to s3 specs we are
-// supposed to only lexically sort keyNames and then for keyNames with
-// multiple upload ids should be sorted based on the initiated time.
-// Currently this case is not handled.
-
 // listMultipartUploadsCommon - lists all multipart uploads, common function for both object layers.
 func (fs fsObjects) listMultipartUploadsCommon(bucket, prefix, keyMarker, uploadIDMarker, delimiter string, maxUploads int) (ListMultipartsInfo, error) {
 	result := ListMultipartsInfo{}
@@ -259,9 +163,12 @@ func (fs fsObjects) listMultipartUploadsCommon(bucket, prefix, keyMarker, upload
 
 	result.IsTruncated = true
 	result.MaxUploads = maxUploads
+	result.KeyMarker = keyMarker
+	result.Prefix = prefix
+	result.Delimiter = delimiter
 
 	// Not using path.Join() as it strips off the trailing '/'.
-	multipartPrefixPath := pathJoin(mpartMetaPrefix, pathJoin(bucket, prefix))
+	multipartPrefixPath := pathJoin(mpartMetaPrefix, bucket, prefix)
 	if prefix == "" {
 		// Should have a trailing "/" if prefix is ""
 		// For ex. multipartPrefixPath should be "multipart/bucket/" if prefix is ""
@@ -269,33 +176,83 @@ func (fs fsObjects) listMultipartUploadsCommon(bucket, prefix, keyMarker, upload
 	}
 	multipartMarkerPath := ""
 	if keyMarker != "" {
-		keyMarkerPath := pathJoin(pathJoin(bucket, keyMarker), uploadIDMarker)
+		multipartMarkerPath = pathJoin(mpartMetaPrefix, bucket, keyMarker)
-		multipartMarkerPath = pathJoin(mpartMetaPrefix, keyMarkerPath)
 	}
-
+	var uploads []uploadMetadata
-	// List all the multipart files at prefixPath, starting with marker keyMarkerPath.
+	var err error
-	fileInfos, eof, err := fs.listMetaBucketMultipart(multipartPrefixPath, multipartMarkerPath, recursive, maxUploads)
+	var eof bool
+	if uploadIDMarker != "" {
+		uploads, _, err = listMultipartUploadIDs(bucket, keyMarker, uploadIDMarker, maxUploads, fs.storage)
 		if err != nil {
 			return ListMultipartsInfo{}, err
 		}
-
+		maxUploads = maxUploads - len(uploads)
-	// Loop through all the received files fill in the multiparts result.
+	}
-	for _, fileInfo := range fileInfos {
+	if maxUploads > 0 {
+		walker := fs.lookupTreeWalk(listParams{minioMetaBucket, recursive, multipartMarkerPath, multipartPrefixPath})
+		if walker == nil {
+			walker = fs.startTreeWalk(minioMetaBucket, multipartPrefixPath, multipartMarkerPath, recursive, func(bucket, object string) bool {
+				return fs.isMultipartUpload(bucket, object)
+			})
+		}
+		for maxUploads > 0 {
+			walkResult, ok := <-walker.ch
+			if !ok {
+				// Closed channel.
+				eof = true
+				break
+			}
+			// For any walk error return right away.
+			if walkResult.err != nil {
+				// File not found or Disk not found is a valid case.
+				if walkResult.err == errFileNotFound || walkResult.err == errDiskNotFound {
+					eof = true
+					break
+				}
+				return ListMultipartsInfo{}, err
+			}
+			entry := strings.TrimPrefix(walkResult.entry, retainSlash(pathJoin(mpartMetaPrefix, bucket)))
+			if strings.HasSuffix(walkResult.entry, slashSeparator) {
+				uploads = append(uploads, uploadMetadata{
+					Object: entry,
+				})
+				maxUploads--
+				if maxUploads == 0 {
+					if walkResult.end {
+						eof = true
+						break
+					}
+				}
+				continue
+			}
+			var tmpUploads []uploadMetadata
+			var end bool
+			uploadIDMarker = ""
+			tmpUploads, end, err = listMultipartUploadIDs(bucket, entry, uploadIDMarker, maxUploads, fs.storage)
+			if err != nil {
+				return ListMultipartsInfo{}, err
+			}
+			uploads = append(uploads, tmpUploads...)
+			maxUploads -= len(tmpUploads)
+			if walkResult.end && end {
+				eof = true
+				break
+			}
+		}
+	}
+	// Loop through all the received uploads fill in the multiparts result.
+	for _, upload := range uploads {
 		var objectName string
 		var uploadID string
-		if fileInfo.Mode.IsDir() {
+		if strings.HasSuffix(upload.Object, slashSeparator) {
 			// All directory entries are common prefixes.
 			uploadID = "" // Upload ids are empty for CommonPrefixes.
-			objectName = strings.TrimPrefix(fileInfo.Name, retainSlash(pathJoin(mpartMetaPrefix, bucket)))
+			objectName = upload.Object
 			result.CommonPrefixes = append(result.CommonPrefixes, objectName)
 		} else {
-			uploadID = path.Base(fileInfo.Name)
+			uploadID = upload.UploadID
-			objectName = strings.TrimPrefix(path.Dir(fileInfo.Name), retainSlash(pathJoin(mpartMetaPrefix, bucket)))
+			objectName = upload.Object
-			result.Uploads = append(result.Uploads, uploadMetadata{
+			result.Uploads = append(result.Uploads, upload)
-				Object:    objectName,
-				UploadID:  uploadID,
-				Initiated: fileInfo.ModTime,
-			})
 		}
 		result.NextKeyMarker = objectName
 		result.NextUploadIDMarker = uploadID
@@ -639,13 +596,17 @@ func (fs fsObjects) abortMultipartUploadCommon(bucket, object, uploadID string)
 
 	// Validate if there are other incomplete upload-id's present for
 	// the object, if yes do not attempt to delete 'uploads.json'.
-	uploadIDs, err := getUploadIDs(bucket, object, fs.storage)
+	uploadsJSON, err := readUploadsJSON(bucket, object, fs.storage)
 	if err == nil {
-		uploadIDIdx := uploadIDs.Index(uploadID)
+		uploadIDIdx := uploadsJSON.Index(uploadID)
 		if uploadIDIdx != -1 {
-			uploadIDs.Uploads = append(uploadIDs.Uploads[:uploadIDIdx], uploadIDs.Uploads[uploadIDIdx+1:]...)
+			uploadsJSON.Uploads = append(uploadsJSON.Uploads[:uploadIDIdx], uploadsJSON.Uploads[uploadIDIdx+1:]...)
+		}
+		if len(uploadsJSON.Uploads) > 0 {
+			err = updateUploadsJSON(bucket, object, uploadsJSON, fs.storage)
+			if err != nil {
+				return toObjectErr(err, bucket, object)
 			}
-		if len(uploadIDs.Uploads) > 0 {
 			return nil
 		}
 	}

fs-v1.go

@@ -20,6 +20,7 @@ import (
 	"crypto/md5"
 	"encoding/hex"
 	"io"
+	"os"
 	"path/filepath"
 	"sort"
 	"strings"
@@ -289,6 +290,22 @@ func isBucketExist(storage StorageAPI, bucketName string) bool {
 }
 
 func (fs fsObjects) listObjectsFS(bucket, prefix, marker, delimiter string, maxKeys int) (ListObjectsInfo, error) {
+	// Convert entry to FileInfo
+	entryToFileInfo := func(entry string) (fileInfo FileInfo, err error) {
+		if strings.HasSuffix(entry, slashSeparator) {
+			// Object name needs to be full path.
+			fileInfo.Name = entry
+			fileInfo.Mode = os.ModeDir
+			return
+		}
+		if fileInfo, err = fs.storage.StatFile(bucket, entry); err != nil {
+			return
+		}
+		// Object name needs to be full path.
+		fileInfo.Name = entry
+		return
+	}
+
 	// Verify if bucket is valid.
 	if !IsValidBucketName(bucket) {
 		return ListObjectsInfo{}, BucketNameInvalid{Bucket: bucket}
@@ -334,7 +351,9 @@ func (fs fsObjects) listObjectsFS(bucket, prefix, marker, delimiter string, maxK
 
 	walker := fs.lookupTreeWalk(listParams{bucket, recursive, marker, prefix})
 	if walker == nil {
-		walker = fs.startTreeWalk(bucket, prefix, marker, recursive)
+		walker = fs.startTreeWalk(bucket, prefix, marker, recursive, func(bucket, object string) bool {
+			return !strings.HasSuffix(object, slashSeparator)
+		})
 	}
 	var fileInfos []FileInfo
 	var eof bool
@@ -354,7 +373,10 @@ func (fs fsObjects) listObjectsFS(bucket, prefix, marker, delimiter string, maxK
 			}
 			return ListObjectsInfo{}, toObjectErr(walkResult.err, bucket, prefix)
 		}
-		fileInfo := walkResult.fileInfo
+		fileInfo, err := entryToFileInfo(walkResult.entry)
+		if err != nil {
+			return ListObjectsInfo{}, nil
+		}
 		nextMarker = fileInfo.Name
 		fileInfos = append(fileInfos, fileInfo)
 		if walkResult.end {

test-utils_test.go

@@ -86,10 +86,8 @@ func ExecObjectLayerTest(t *testing.T, objTest func(obj ObjectLayer, instanceTyp
 		t.Fatalf("Initialization of object layer failed for single node setup: %s", err.Error())
 	}
 	// FIXME: enable FS tests after fixing it.
-	if false {
 	// Executing the object layer tests for single node setup.
 	objTest(objLayer, singleNodeTestStr, t)
-	}
 
 	objLayer, fsDirs, err := getXLObjectLayer()
 	if err != nil {

tree-walk-fs.go

@@ -17,7 +17,6 @@
 package main
 
 import (
-	"os"
 	"path"
 	"sort"
 	"strings"
@@ -34,34 +33,17 @@ type treeWalkerFS struct {
 
 // Tree walk result carries results of tree walking.
 type treeWalkResultFS struct {
-	fileInfo FileInfo
+	entry string
 	err   error
 	end   bool
 }
 
 // treeWalk walks FS directory tree recursively pushing fileInfo into the channel as and when it encounters files.
-func (fs fsObjects) treeWalk(bucket, prefixDir, entryPrefixMatch, marker string, recursive bool, send func(treeWalkResultFS) bool, count *int) bool {
+func (fs fsObjects) treeWalk(bucket, prefixDir, entryPrefixMatch, marker string, recursive bool, send func(treeWalkResultFS) bool, count *int, isLeaf func(string, string) bool) bool {
 	// Example:
 	// if prefixDir="one/two/three/" and marker="four/five.txt" treeWalk is recursively
 	// called with prefixDir="one/two/three/four/" and marker="five.txt"
 
-	// Convert entry to FileInfo
-	entryToFileInfo := func(entry string) (fileInfo FileInfo, err error) {
-		if strings.HasSuffix(entry, slashSeparator) {
-			// Object name needs to be full path.
-			fileInfo.Name = path.Join(prefixDir, entry)
-			fileInfo.Name += slashSeparator
-			fileInfo.Mode = os.ModeDir
-			return
-		}
-		if fileInfo, err = fs.storage.StatFile(bucket, path.Join(prefixDir, entry)); err != nil {
-			return
-		}
-		// Object name needs to be full path.
-		fileInfo.Name = path.Join(prefixDir, entry)
-		return
-	}
-
 	var markerBase, markerDir string
 	if marker != "" {
 		// Ex: if marker="four/five.txt", markerDir="four/" markerBase="five.txt"
@@ -78,11 +60,15 @@ func (fs fsObjects) treeWalk(bucket, prefixDir, entryPrefixMatch, marker string,
 		return false
 	}
 
-	if entryPrefixMatch != "" {
 	for i, entry := range entries {
+		if entryPrefixMatch != "" {
 			if !strings.HasPrefix(entry, entryPrefixMatch) {
 				entries[i] = ""
+				continue
+			}
 		}
+		if isLeaf(bucket, pathJoin(prefixDir, entry)) {
+			entries[i] = strings.TrimSuffix(entry, slashSeparator)
 		}
 	}
 	sort.Strings(entries)
@@ -129,19 +115,13 @@ func (fs fsObjects) treeWalk(bucket, prefixDir, entryPrefixMatch, marker string,
 			}
 			*count--
 			prefixMatch := "" // Valid only for first level treeWalk and empty for subdirectories.
-			if !fs.treeWalk(bucket, path.Join(prefixDir, entry), prefixMatch, markerArg, recursive, send, count) {
+			if !fs.treeWalk(bucket, path.Join(prefixDir, entry), prefixMatch, markerArg, recursive, send, count, isLeaf) {
 				return false
 			}
 			continue
 		}
 		*count--
-		fileInfo, err := entryToFileInfo(entry)
+		if !send(treeWalkResultFS{entry: pathJoin(prefixDir, entry)}) {
-		if err != nil {
-			// The file got deleted in the interim between ListDir() and StatFile()
-			// Ignore error and continue.
-			continue
-		}
-		if !send(treeWalkResultFS{fileInfo: fileInfo}) {
 			return false
 		}
 	}
@@ -149,7 +129,7 @@ func (fs fsObjects) treeWalk(bucket, prefixDir, entryPrefixMatch, marker string,
 }
 
 // Initiate a new treeWalk in a goroutine.
-func (fs fsObjects) startTreeWalk(bucket, prefix, marker string, recursive bool) *treeWalkerFS {
+func (fs fsObjects) startTreeWalk(bucket, prefix, marker string, recursive bool, isLeaf func(string, string) bool) *treeWalkerFS {
 	// Example 1
 	// If prefix is "one/two/three/" and marker is "one/two/three/four/five.txt"
 	// treeWalk is called with prefixDir="one/two/three/" and marker="four/five.txt"
@@ -186,7 +166,7 @@ func (fs fsObjects) startTreeWalk(bucket, prefix, marker string, recursive bool)
 				return false
 			}
 		}
-		fs.treeWalk(bucket, prefixDir, entryPrefixMatch, marker, recursive, send, &count)
+		fs.treeWalk(bucket, prefixDir, entryPrefixMatch, marker, recursive, send, &count, isLeaf)
 	}()
 	return &walkNotify
 }

xl-v1-multipart-common.go

@@ -91,15 +91,17 @@ func (u uploadsV1) WriteTo(writer io.Writer) (n int64, err error) {
 	return int64(m), err
 }
 
-// getUploadIDs - get all the saved upload id's.
+// readUploadsJSON - get all the saved uploads JSON.
-func getUploadIDs(bucket, object string, storageDisks ...StorageAPI) (uploadIDs uploadsV1, err error) {
+func readUploadsJSON(bucket, object string, storageDisks ...StorageAPI) (uploadIDs uploadsV1, err error) {
 	uploadJSONPath := path.Join(mpartMetaPrefix, bucket, object, uploadsJSONFile)
 	var errs = make([]error, len(storageDisks))
 	var uploads = make([]uploadsV1, len(storageDisks))
 	var wg = &sync.WaitGroup{}
 
+	// Read `uploads.json` from all disks.
 	for index, disk := range storageDisks {
 		wg.Add(1)
+		// Read `uploads.json` in a routine.
 		go func(index int, disk StorageAPI) {
 			defer wg.Done()
 			r, rErr := disk.ReadFile(minioMetaBucket, uploadJSONPath, int64(0))
@@ -116,8 +118,11 @@ func getUploadIDs(bucket, object string, storageDisks ...StorageAPI) (uploadIDs
 			errs[index] = nil
 		}(index, disk)
 	}
+
+	// Wait for all the routines.
 	wg.Wait()
 
+	// Return for first error.
 	for _, err = range errs {
 		if err != nil {
 			return uploadsV1{}, err
@@ -128,13 +133,16 @@ func getUploadIDs(bucket, object string, storageDisks ...StorageAPI) (uploadIDs
 	return uploads[0], nil
 }
 
-func updateUploadJSON(bucket, object string, uploadIDs uploadsV1, storageDisks ...StorageAPI) error {
+// uploadUploadsJSON - update `uploads.json` with new uploadsJSON for all disks.
+func updateUploadsJSON(bucket, object string, uploadsJSON uploadsV1, storageDisks ...StorageAPI) error {
 	uploadsPath := path.Join(mpartMetaPrefix, bucket, object, uploadsJSONFile)
 	var errs = make([]error, len(storageDisks))
 	var wg = &sync.WaitGroup{}
 
+	// Update `uploads.json` for all the disks.
 	for index, disk := range storageDisks {
 		wg.Add(1)
+		// Update `uploads.json` in routine.
 		go func(index int, disk StorageAPI) {
 			defer wg.Done()
 			w, wErr := disk.CreateFile(minioMetaBucket, uploadsPath)
@@ -142,7 +150,7 @@ func updateUploadJSON(bucket, object string, uploadIDs uploadsV1, storageDisks .
 				errs[index] = wErr
 				return
 			}
-			_, wErr = uploadIDs.WriteTo(w)
+			_, wErr = uploadsJSON.WriteTo(w)
 			if wErr != nil {
 				errs[index] = wErr
 				return
@@ -158,8 +166,10 @@ func updateUploadJSON(bucket, object string, uploadIDs uploadsV1, storageDisks .
 		}(index, disk)
 	}
 
+	// Wait for all the routines to finish updating `uploads.json`
 	wg.Wait()
 
+	// Return for first error.
 	for _, err := range errs {
 		if err != nil {
 			return err
@@ -169,24 +179,44 @@ func updateUploadJSON(bucket, object string, uploadIDs uploadsV1, storageDisks .
 	return nil
 }
 
+// newUploadsV1 - initialize new uploads v1.
+func newUploadsV1(format string) uploadsV1 {
+	uploadIDs := uploadsV1{}
+	uploadIDs.Version = "1"
+	uploadIDs.Format = format
+	return uploadIDs
+}
+
 // writeUploadJSON - create `uploads.json` or update it with new uploadID.
-func writeUploadJSON(bucket, object, uploadID string, initiated time.Time, storageDisks ...StorageAPI) error {
+func writeUploadJSON(bucket, object, uploadID string, initiated time.Time, storageDisks ...StorageAPI) (err error) {
 	uploadsPath := path.Join(mpartMetaPrefix, bucket, object, uploadsJSONFile)
 	tmpUploadsPath := path.Join(tmpMetaPrefix, bucket, object, uploadsJSONFile)
 
 	var errs = make([]error, len(storageDisks))
 	var wg = &sync.WaitGroup{}
 
-	uploadIDs, err := getUploadIDs(bucket, object, storageDisks...)
+	var uploadsJSON uploadsV1
-	if err != nil && err != errFileNotFound {
+	uploadsJSON, err = readUploadsJSON(bucket, object, storageDisks...)
+	if err != nil {
+		// For any other errors.
+		if err != errFileNotFound {
 			return err
 		}
-	uploadIDs.Version = "1"
+		if len(storageDisks) == 1 {
-	uploadIDs.Format = "xl"
+			// Set uploads format to `fs` for single disk.
-	uploadIDs.AddUploadID(uploadID, initiated)
+			uploadsJSON = newUploadsV1("fs")
+		} else {
+			// Set uploads format to `xl` otherwise.
+			uploadsJSON = newUploadsV1("xl")
+		}
+	}
+	// Add a new upload id.
+	uploadsJSON.AddUploadID(uploadID, initiated)
 
+	// Update `uploads.json` on all disks.
 	for index, disk := range storageDisks {
 		wg.Add(1)
+		// Update `uploads.json` in a routine.
 		go func(index int, disk StorageAPI) {
 			defer wg.Done()
 			w, wErr := disk.CreateFile(minioMetaBucket, tmpUploadsPath)
@@ -194,7 +224,7 @@ func writeUploadJSON(bucket, object, uploadID string, initiated time.Time, stora
 				errs[index] = wErr
 				return
 			}
-			_, wErr = uploadIDs.WriteTo(w)
+			_, wErr = uploadsJSON.WriteTo(w)
 			if wErr != nil {
 				errs[index] = wErr
 				return
@@ -220,8 +250,10 @@ func writeUploadJSON(bucket, object, uploadID string, initiated time.Time, stora
 		}(index, disk)
 	}
 
+	// Wait for all the writes to finish.
 	wg.Wait()
 
+	// Return for first error encountered.
 	for _, err = range errs {
 		if err != nil {
 			return err
@@ -235,11 +267,17 @@ func writeUploadJSON(bucket, object, uploadID string, initiated time.Time, stora
 func cleanupUploadedParts(bucket, object, uploadID string, storageDisks ...StorageAPI) error {
 	var errs = make([]error, len(storageDisks))
 	var wg = &sync.WaitGroup{}
+
+	// Construct uploadIDPath.
+	uploadIDPath := path.Join(mpartMetaPrefix, bucket, object, uploadID)
+
+	// Cleanup uploadID for all disks.
 	for index, disk := range storageDisks {
 		wg.Add(1)
+		// Cleanup each uploadID in a routine.
 		go func(index int, disk StorageAPI) {
 			defer wg.Done()
-			err := cleanupDir(disk, minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object, uploadID))
+			err := cleanupDir(disk, minioMetaBucket, uploadIDPath)
 			if err != nil {
 				errs[index] = err
 				return
@@ -247,8 +285,11 @@ func cleanupUploadedParts(bucket, object, uploadID string, storageDisks ...Stora
 			errs[index] = nil
 		}(index, disk)
 	}
+
+	// Wait for all the cleanups to finish.
 	wg.Wait()
 
+	// Return first error.
 	for _, err := range errs {
 		if err != nil {
 			return err
@@ -257,49 +298,29 @@ func cleanupUploadedParts(bucket, object, uploadID string, storageDisks ...Stora
 	return nil
 }
 
-// Returns if the prefix is a multipart upload.
+// listMultipartUploadIDs - list all the upload ids from a marker up to 'count'.
-func (xl xlObjects) isMultipartUpload(bucket, prefix string) bool {
+func listMultipartUploadIDs(bucketName, objectName, uploadIDMarker string, count int, disk StorageAPI) ([]uploadMetadata, bool, error) {
-	disk := xl.getRandomDisk() // Choose a random disk.
-	_, err := disk.StatFile(bucket, pathJoin(prefix, uploadsJSONFile))
-	return err == nil
-}
-
-// listUploadsInfo - list all uploads info.
-func (xl xlObjects) listUploadsInfo(prefixPath string) (uploads []uploadInfo, err error) {
-	disk := xl.getRandomDisk() // Choose a random disk on each attempt.
-	splitPrefixes := strings.SplitN(prefixPath, "/", 3)
-	uploadIDs, err := getUploadIDs(splitPrefixes[1], splitPrefixes[2], disk)
-	if err != nil {
-		if err == errFileNotFound {
-			return []uploadInfo{}, nil
-		}
-		return nil, err
-	}
-	uploads = uploadIDs.Uploads
-	return uploads, nil
-}
-
-func (xl xlObjects) listMultipartUploadIDs(bucketName, objectName, uploadIDMarker string, count int) ([]uploadMetadata, bool, error) {
 	var uploads []uploadMetadata
-	uploadsJSONContent, err := getUploadIDs(bucketName, objectName, xl.getRandomDisk())
+	// Read `uploads.json`.
+	uploadsJSON, err := readUploadsJSON(bucketName, objectName, disk)
 	if err != nil {
 		return nil, false, err
 	}
 	index := 0
 	if uploadIDMarker != "" {
-		for ; index < len(uploadsJSONContent.Uploads); index++ {
+		for ; index < len(uploadsJSON.Uploads); index++ {
-			if uploadsJSONContent.Uploads[index].UploadID == uploadIDMarker {
+			if uploadsJSON.Uploads[index].UploadID == uploadIDMarker {
 				// Skip the uploadID as it would already be listed in previous listing.
 				index++
 				break
 			}
 		}
 	}
-	for index < len(uploadsJSONContent.Uploads) {
+	for index < len(uploadsJSON.Uploads) {
 		uploads = append(uploads, uploadMetadata{
 			Object:    objectName,
-			UploadID:  uploadsJSONContent.Uploads[index].UploadID,
+			UploadID:  uploadsJSON.Uploads[index].UploadID,
-			Initiated: uploadsJSONContent.Uploads[index].Initiated,
+			Initiated: uploadsJSON.Uploads[index].Initiated,
 		})
 		count--
 		index++
@@ -307,7 +328,30 @@ func (xl xlObjects) listMultipartUploadIDs(bucketName, objectName, uploadIDMarke
 			break
 		}
 	}
-	return uploads, index == len(uploadsJSONContent.Uploads), nil
+	end := (index == len(uploadsJSON.Uploads))
+	return uploads, end, nil
+}
+
+// Returns if the prefix is a multipart upload.
+func (xl xlObjects) isMultipartUpload(bucket, prefix string) bool {
+	disk := xl.getRandomDisk() // Choose a random disk.
+	_, err := disk.StatFile(bucket, pathJoin(prefix, uploadsJSONFile))
+	return err == nil
+}
+
+// listUploadsInfo - list all uploads info.
+func (xl xlObjects) listUploadsInfo(prefixPath string) (uploadsInfo []uploadInfo, err error) {
+	disk := xl.getRandomDisk() // Choose a random disk on each attempt.
+	splitPrefixes := strings.SplitN(prefixPath, "/", 3)
+	uploadsJSON, err := readUploadsJSON(splitPrefixes[1], splitPrefixes[2], disk)
+	if err != nil {
+		if err == errFileNotFound {
+			return []uploadInfo{}, nil
+		}
+		return nil, err
+	}
+	uploadsInfo = uploadsJSON.Uploads
+	return uploadsInfo, nil
 }
 
 // listMultipartUploadsCommon - lists all multipart uploads, common
@@ -381,7 +425,7 @@ func (xl xlObjects) listMultipartUploadsCommon(bucket, prefix, keyMarker, upload
 	var err error
 	var eof bool
 	if uploadIDMarker != "" {
-		uploads, _, err = xl.listMultipartUploadIDs(bucket, keyMarker, uploadIDMarker, maxUploads)
+		uploads, _, err = listMultipartUploadIDs(bucket, keyMarker, uploadIDMarker, maxUploads, xl.getRandomDisk())
 		if err != nil {
 			return ListMultipartsInfo{}, err
 		}
@@ -422,15 +466,15 @@ func (xl xlObjects) listMultipartUploadsCommon(bucket, prefix, keyMarker, upload
 				}
 				continue
 			}
-			var tmpUploads []uploadMetadata
+			var newUploads []uploadMetadata
 			var end bool
 			uploadIDMarker = ""
-			tmpUploads, end, err = xl.listMultipartUploadIDs(bucket, entry, uploadIDMarker, maxUploads)
+			newUploads, end, err = listMultipartUploadIDs(bucket, entry, uploadIDMarker, maxUploads, xl.getRandomDisk())
 			if err != nil {
 				return ListMultipartsInfo{}, err
 			}
-			uploads = append(uploads, tmpUploads...)
+			uploads = append(uploads, newUploads...)
-			maxUploads -= len(tmpUploads)
+			maxUploads -= len(newUploads)
 			if walkResult.end && end {
 				eof = true
 				break

xl-v1-multipart.go

@@ -416,14 +416,14 @@ func (xl xlObjects) CompleteMultipartUpload(bucket string, object string, upload
 
 	// Validate if there are other incomplete upload-id's present for
 	// the object, if yes do not attempt to delete 'uploads.json'.
-	uploadIDs, err := getUploadIDs(bucket, object, xl.storageDisks...)
+	uploadsJSON, err := readUploadsJSON(bucket, object, xl.storageDisks...)
 	if err == nil {
-		uploadIDIdx := uploadIDs.Index(uploadID)
+		uploadIDIdx := uploadsJSON.Index(uploadID)
 		if uploadIDIdx != -1 {
-			uploadIDs.Uploads = append(uploadIDs.Uploads[:uploadIDIdx], uploadIDs.Uploads[uploadIDIdx+1:]...)
+			uploadsJSON.Uploads = append(uploadsJSON.Uploads[:uploadIDIdx], uploadsJSON.Uploads[uploadIDIdx+1:]...)
 		}
-		if len(uploadIDs.Uploads) > 0 {
+		if len(uploadsJSON.Uploads) > 0 {
-			if err = updateUploadJSON(bucket, object, uploadIDs, xl.storageDisks...); err != nil {
+			if err = updateUploadsJSON(bucket, object, uploadsJSON, xl.storageDisks...); err != nil {
 				return "", err
 			}
 			return s3MD5, nil
@@ -461,20 +461,21 @@ func (xl xlObjects) abortMultipartUploadCommon(bucket, object, uploadID string)
 
 	// Cleanup all uploaded parts.
 	if err := cleanupUploadedParts(bucket, object, uploadID, xl.storageDisks...); err != nil {
-		return err
+		return toObjectErr(err, bucket, object)
 	}
 
 	// Validate if there are other incomplete upload-id's present for
 	// the object, if yes do not attempt to delete 'uploads.json'.
-	uploadIDs, err := getUploadIDs(bucket, object, xl.storageDisks...)
+	uploadsJSON, err := readUploadsJSON(bucket, object, xl.storageDisks...)
 	if err == nil {
-		uploadIDIdx := uploadIDs.Index(uploadID)
+		uploadIDIdx := uploadsJSON.Index(uploadID)
 		if uploadIDIdx != -1 {
-			uploadIDs.Uploads = append(uploadIDs.Uploads[:uploadIDIdx], uploadIDs.Uploads[uploadIDIdx+1:]...)
+			uploadsJSON.Uploads = append(uploadsJSON.Uploads[:uploadIDIdx], uploadsJSON.Uploads[uploadIDIdx+1:]...)
 		}
-		if len(uploadIDs.Uploads) > 0 {
+		if len(uploadsJSON.Uploads) > 0 {
-			if err = updateUploadJSON(bucket, object, uploadIDs, xl.storageDisks...); err != nil {
+			err = updateUploadsJSON(bucket, object, uploadsJSON, xl.storageDisks...)
-				return err
+			if err != nil {
+				return toObjectErr(err, bucket, object)
 			}
 			return nil
 		}