Read/write quorum algo with uploads.json in xl (Fixes #3123) (#3124)

- Reads and writes of uploads.json in XL now uses quorum for
  newMultipart, completeMultipart and abortMultipart operations.

- Each disk's `uploads.json` file is read and updated independently for
  adding or removing an upload id from the file. Quorum is used to
  decide if the high-level operation actually succeeded.

- Refactor FS code to simplify the flow, and fix a bug while reading
  uploads.json.

cmd/fs-v1-multipart-common.go

@@ -16,11 +16,7 @@
 
 package cmd
 
-import (
+import "path"
-	"encoding/json"
-	"path"
-	"time"
-)
 
 // Returns if the prefix is a multipart upload.
 func (fs fsObjects) isMultipartUpload(bucket, prefix string) bool {
@@ -57,56 +53,38 @@ func (fs fsObjects) isUploadIDExists(bucket, object, uploadID string) bool {
 }
 
 // writeUploadJSON - create `uploads.json` or update it with new uploadID.
-func (fs fsObjects) writeUploadJSON(bucket, object, uploadID string, initiated time.Time) (err error) {
+func (fs fsObjects) updateUploadJSON(bucket, object string, uCh uploadIDChange) error {
 	uploadsPath := path.Join(mpartMetaPrefix, bucket, object, uploadsJSONFile)
 	uniqueID := getUUID()
 	tmpUploadsPath := path.Join(tmpMetaPrefix, uniqueID)
-	var uploadsJSON uploadsV1
+
-	uploadsJSON, err = readUploadsJSON(bucket, object, fs.storage)
+	uploadsJSON, err := readUploadsJSON(bucket, object, fs.storage)
+	if errorCause(err) == errFileNotFound {
+		// If file is not found, we assume a default (empty)
+		// upload info.
+		uploadsJSON, err = newUploadsV1("fs"), nil
+	}
 	if err != nil {
-		// uploads.json might not exist hence ignore errFileNotFound.
-		if errorCause(err) != errFileNotFound {
 		return err
 	}
-		// Set uploads format to `fs`.
-		uploadsJSON = newUploadsV1("fs")
-	}
-	// Add a new upload id.
-	uploadsJSON.AddUploadID(uploadID, initiated)
 
-	// Update `uploads.json` on all disks.
+	// update the uploadsJSON struct
-	uploadsJSONBytes, wErr := json.Marshal(&uploadsJSON)
+	if !uCh.isRemove {
-	if wErr != nil {
+		// Add the uploadID
-		return traceError(wErr)
+		uploadsJSON.AddUploadID(uCh.uploadID, uCh.initiated)
-	}
+	} else {
-	// Write `uploads.json` to disk.
+		// Remove the upload ID
-	if wErr = fs.storage.AppendFile(minioMetaBucket, tmpUploadsPath, uploadsJSONBytes); wErr != nil {
+		uploadsJSON.RemoveUploadID(uCh.uploadID)
-		return traceError(wErr)
-	}
-	wErr = fs.storage.RenameFile(minioMetaBucket, tmpUploadsPath, minioMetaBucket, uploadsPath)
-	if wErr != nil {
-		if dErr := fs.storage.DeleteFile(minioMetaBucket, tmpUploadsPath); dErr != nil {
-			return traceError(dErr)
-		}
-		return traceError(wErr)
-	}
-	return nil
 	}
 
-// updateUploadsJSON - update `uploads.json` with new uploadsJSON for all disks.
+	// update the file or delete it?
-func (fs fsObjects) updateUploadsJSON(bucket, object string, uploadsJSON uploadsV1) (err error) {
+	if len(uploadsJSON.Uploads) > 0 {
-	uploadsPath := path.Join(mpartMetaPrefix, bucket, object, uploadsJSONFile)
+		err = writeUploadJSON(&uploadsJSON, uploadsPath, tmpUploadsPath, fs.storage)
-	uniqueID := getUUID()
+	} else {
-	tmpUploadsPath := path.Join(tmpMetaPrefix, uniqueID)
+		// no uploads, so we delete the file.
-	uploadsBytes, wErr := json.Marshal(uploadsJSON)
+		if err = fs.storage.DeleteFile(minioMetaBucket, uploadsPath); err != nil {
-	if wErr != nil {
+			return toObjectErr(traceError(err), minioMetaBucket, uploadsPath)
-		return traceError(wErr)
 		}
-	if wErr = fs.storage.AppendFile(minioMetaBucket, tmpUploadsPath, uploadsBytes); wErr != nil {
-		return traceError(wErr)
 	}
-	if wErr = fs.storage.RenameFile(minioMetaBucket, tmpUploadsPath, minioMetaBucket, uploadsPath); wErr != nil {
+	return err
-		return traceError(wErr)
-	}
-	return nil
 }

cmd/fs-v1-multipart-common_test.go

@@ -122,7 +122,7 @@ func TestFSWriteUploadJSON(t *testing.T) {
 		t.Fatal("Unexpected err: ", err)
 	}
 
-	if err := fs.writeUploadJSON(bucketName, objectName, uploadID, time.Now().UTC()); err != nil {
+	if err := fs.updateUploadJSON(bucketName, objectName, uploadIDChange{uploadID, time.Now().UTC(), false}); err != nil {
 		t.Fatal("Unexpected err: ", err)
 	}
 
@@ -131,36 +131,8 @@ func TestFSWriteUploadJSON(t *testing.T) {
 	for i := 1; i <= 3; i++ {
 		naughty := newNaughtyDisk(fsStorage, map[int]error{i: errFaultyDisk}, nil)
 		fs.storage = naughty
-		if err := fs.writeUploadJSON(bucketName, objectName, uploadID, time.Now().UTC()); errorCause(err) != errFaultyDisk {
+		if err := fs.updateUploadJSON(bucketName, objectName,
-			t.Fatal("Unexpected err: ", err)
+			uploadIDChange{uploadID, time.Now().UTC(), false}); errorCause(err) != errFaultyDisk {
-		}
-	}
-}
-
-// TestFSUpdateUploadsJSON - tests for updateUploadsJSON for FS
-func TestFSUpdateUploadsJSON(t *testing.T) {
-	// Prepare for tests
-	disk := filepath.Join(os.TempDir(), "minio-"+nextSuffix())
-	defer removeAll(disk)
-
-	obj := initFSObjects(disk, t)
-	fs := obj.(fsObjects)
-
-	bucketName := "bucket"
-	objectName := "object"
-
-	obj.MakeBucket(bucketName)
-
-	if err := fs.updateUploadsJSON(bucketName, objectName, uploadsV1{}); err != nil {
-		t.Fatal("Unexpected err: ", err)
-	}
-
-	// isUploadIdExists with a faulty disk should return false
-	fsStorage := fs.storage.(*posix)
-	for i := 1; i <= 2; i++ {
-		naughty := newNaughtyDisk(fsStorage, map[int]error{i: errFaultyDisk}, nil)
-		fs.storage = naughty
-		if err := fs.updateUploadsJSON(bucketName, objectName, uploadsV1{}); errorCause(err) != errFaultyDisk {
 			t.Fatal("Unexpected err: ", err)
 		}
 	}

cmd/fs-v1-multipart.go

@@ -243,7 +243,7 @@ func (fs fsObjects) newMultipartUpload(bucket string, object string, meta map[st
 	uploadID = getUUID()
 	initiated := time.Now().UTC()
 	// Create 'uploads.json'
-	if err = fs.writeUploadJSON(bucket, object, uploadID, initiated); err != nil {
+	if err = fs.updateUploadJSON(bucket, object, uploadIDChange{uploadID, initiated, false}); err != nil {
 		return "", err
 	}
 	uploadIDPath := path.Join(mpartMetaPrefix, bucket, object, uploadID)
@@ -791,29 +791,10 @@ func (fs fsObjects) CompleteMultipartUpload(bucket string, object string, upload
 	nsMutex.Lock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object), opsID)
 	defer nsMutex.Unlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object), opsID)
 
-	// Validate if there are other incomplete upload-id's present for
+	// remove entry from uploads.json
-	// the object, if yes do not attempt to delete 'uploads.json'.
+	if err = fs.updateUploadJSON(bucket, object, uploadIDChange{uploadID: uploadID, isRemove: true}); err != nil {
-	uploadsJSON, err := readUploadsJSON(bucket, object, fs.storage)
-	if err != nil {
-		return "", toObjectErr(err, minioMetaBucket, object)
-	}
-	// If we have successfully read `uploads.json`, then we proceed to
-	// purge or update `uploads.json`.
-	uploadIDIdx := uploadsJSON.Index(uploadID)
-	if uploadIDIdx != -1 {
-		uploadsJSON.Uploads = append(uploadsJSON.Uploads[:uploadIDIdx], uploadsJSON.Uploads[uploadIDIdx+1:]...)
-	}
-	if len(uploadsJSON.Uploads) > 0 {
-		if err = fs.updateUploadsJSON(bucket, object, uploadsJSON); err != nil {
 		return "", toObjectErr(err, minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object))
 	}
-		// Return success.
-		return s3MD5, nil
-	}
-
-	if err = fs.storage.DeleteFile(minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object, uploadsJSONFile)); err != nil {
-		return "", toObjectErr(traceError(err), minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object))
-	}
 
 	// Return md5sum.
 	return s3MD5, nil
@@ -829,28 +810,12 @@ func (fs fsObjects) abortMultipartUpload(bucket, object, uploadID string) error
 		return err
 	}
 
-	// Validate if there are other incomplete upload-id's present for
+	// remove entry from uploads.json with quorum
-	// the object, if yes do not attempt to delete 'uploads.json'.
+	if err := fs.updateUploadJSON(bucket, object, uploadIDChange{uploadID: uploadID, isRemove: true}); err != nil {
-	uploadsJSON, err := readUploadsJSON(bucket, object, fs.storage)
-	if err == nil {
-		uploadIDIdx := uploadsJSON.Index(uploadID)
-		if uploadIDIdx != -1 {
-			uploadsJSON.Uploads = append(uploadsJSON.Uploads[:uploadIDIdx], uploadsJSON.Uploads[uploadIDIdx+1:]...)
-		}
-		// There are pending uploads for the same object, preserve
-		// them update 'uploads.json' in-place.
-		if len(uploadsJSON.Uploads) > 0 {
-			err = fs.updateUploadsJSON(bucket, object, uploadsJSON)
-			if err != nil {
 		return toObjectErr(err, bucket, object)
 	}
-			return nil
+
-		}
+	// success
-	} // No more pending uploads for the object, we purge the entire
-	// entry at '.minio.sys/multipart/bucket/object'.
-	if err = fs.storage.DeleteFile(minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object, uploadsJSONFile)); err != nil {
-		return toObjectErr(traceError(err), minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object))
-	}
 	return nil
 }
 

cmd/object-multipart-common.go

@@ -56,6 +56,17 @@ func (u *uploadsV1) AddUploadID(uploadID string, initiated time.Time) {
 	sort.Sort(byInitiatedTime(u.Uploads))
 }
 
+// RemoveUploadID - removes upload id from uploads metadata.
+func (u *uploadsV1) RemoveUploadID(uploadID string) {
+	// If the uploadID is absent, we do nothing.
+	for i, uInfo := range u.Uploads {
+		if uInfo.UploadID == uploadID {
+			u.Uploads = append(u.Uploads[:i], u.Uploads[i+1:]...)
+			break
+		}
+	}
+}
+
 // Index - returns the index of matching the upload id.
 func (u uploadsV1) Index(uploadID string) int {
 	for i, u := range u.Uploads {
@@ -92,6 +103,40 @@ func newUploadsV1(format string) uploadsV1 {
 	return uploadIDs
 }
 
+// uploadIDChange - represents a change to uploads.json - either add
+// or remove an upload id.
+type uploadIDChange struct {
+	// the id being added or removed.
+	uploadID string
+	// time of upload start. only used in uploadid add operations.
+	initiated time.Time
+	// if true, removes uploadID and ignores initiated time.
+	isRemove bool
+}
+
+func writeUploadJSON(u *uploadsV1, uploadsPath, tmpPath string, disk StorageAPI) error {
+	// Serialize to prepare to write to disk.
+	uplBytes, wErr := json.Marshal(&u)
+	if wErr != nil {
+		return traceError(wErr)
+	}
+
+	// Write `uploads.json` to disk. First to tmp location and
+	// then rename.
+	if wErr = disk.AppendFile(minioMetaBucket, tmpPath, uplBytes); wErr != nil {
+		return traceError(wErr)
+	}
+	wErr = disk.RenameFile(minioMetaBucket, tmpPath, minioMetaBucket, uploadsPath)
+	if wErr != nil {
+		if dErr := disk.DeleteFile(minioMetaBucket, tmpPath); dErr != nil {
+			// we return the most recent error.
+			return traceError(dErr)
+		}
+		return traceError(wErr)
+	}
+	return nil
+}
+
 // Wrapper which removes all the uploaded parts.
 func cleanupUploadedParts(bucket, object, uploadID string, storageDisks ...StorageAPI) error {
 	var errs = make([]error, len(storageDisks))

cmd/xl-v1-multipart-common.go

@@ -17,172 +17,129 @@
 package cmd
 
 import (
-	"encoding/json"
 	"path"
 	"sync"
-	"time"
 )
 
-// updateUploadsJSON - update `uploads.json` with new uploadsJSON for all disks.
+// writeUploadJSON - create `uploads.json` or update it with change
-func (xl xlObjects) updateUploadsJSON(bucket, object string, uploadsJSON uploadsV1) (err error) {
+// described in uCh.
-	uploadsPath := path.Join(mpartMetaPrefix, bucket, object, uploadsJSONFile)
+func (xl xlObjects) updateUploadJSON(bucket, object string, uCh uploadIDChange) error {
-	uniqueID := getUUID()
-	tmpUploadsPath := path.Join(tmpMetaPrefix, uniqueID)
-	var errs = make([]error, len(xl.storageDisks))
-	var wg = &sync.WaitGroup{}
-
-	// Update `uploads.json` for all the disks.
-	for index, disk := range xl.storageDisks {
-		if disk == nil {
-			errs[index] = errDiskNotFound
-			continue
-		}
-		wg.Add(1)
-		// Update `uploads.json` in routine.
-		go func(index int, disk StorageAPI) {
-			defer wg.Done()
-			uploadsBytes, wErr := json.Marshal(uploadsJSON)
-			if wErr != nil {
-				errs[index] = traceError(wErr)
-				return
-			}
-			if wErr = disk.AppendFile(minioMetaBucket, tmpUploadsPath, uploadsBytes); wErr != nil {
-				errs[index] = traceError(wErr)
-				return
-			}
-			if wErr = disk.RenameFile(minioMetaBucket, tmpUploadsPath, minioMetaBucket, uploadsPath); wErr != nil {
-				errs[index] = traceError(wErr)
-				return
-			}
-		}(index, disk)
-	}
-
-	// Wait for all the routines to finish updating `uploads.json`
-	wg.Wait()
-
-	// Count all the errors and validate if we have write quorum.
-	if !isDiskQuorum(errs, xl.writeQuorum) {
-		// Do we have readQuorum?.
-		if isDiskQuorum(errs, xl.readQuorum) {
-			return nil
-		}
-		// Rename `uploads.json` left over back to tmp location.
-		for index, disk := range xl.storageDisks {
-			if disk == nil {
-				continue
-			}
-			// Undo rename `uploads.json` in parallel.
-			wg.Add(1)
-			go func(index int, disk StorageAPI) {
-				defer wg.Done()
-				if errs[index] != nil {
-					return
-				}
-				_ = disk.RenameFile(minioMetaBucket, uploadsPath, minioMetaBucket, tmpUploadsPath)
-			}(index, disk)
-		}
-		wg.Wait()
-		return traceError(errXLWriteQuorum)
-	}
-	return nil
-}
-
-// Reads uploads.json from any of the load balanced disks.
-func (xl xlObjects) readUploadsJSON(bucket, object string) (uploadsJSON uploadsV1, err error) {
-	for _, disk := range xl.getLoadBalancedDisks() {
-		if disk == nil {
-			continue
-		}
-		uploadsJSON, err = readUploadsJSON(bucket, object, disk)
-		if err == nil {
-			return uploadsJSON, nil
-		}
-		if isErrIgnored(err, objMetadataOpIgnoredErrs) {
-			continue
-		}
-		break
-	}
-	return uploadsV1{}, err
-}
-
-// writeUploadJSON - create `uploads.json` or update it with new uploadID.
-func (xl xlObjects) writeUploadJSON(bucket, object, uploadID string, initiated time.Time) (err error) {
 	uploadsPath := path.Join(mpartMetaPrefix, bucket, object, uploadsJSONFile)
 	uniqueID := getUUID()
 	tmpUploadsPath := path.Join(tmpMetaPrefix, uniqueID)
 
-	var errs = make([]error, len(xl.storageDisks))
+	// slice to store errors from disks
-	var wg = &sync.WaitGroup{}
+	errs := make([]error, len(xl.storageDisks))
+	// slice to store if it is a delete operation on a disk
+	isDelete := make([]bool, len(xl.storageDisks))
 
-	// Reads `uploads.json` and returns error.
+	wg := sync.WaitGroup{}
-	uploadsJSON, err := xl.readUploadsJSON(bucket, object)
-	if err != nil {
-		if errorCause(err) != errFileNotFound {
-			return err
-		}
-		// 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 xl.storageDisks {
 		if disk == nil {
 			errs[index] = traceError(errDiskNotFound)
 			continue
 		}
+		// Update `uploads.json` in a go routine.
 		wg.Add(1)
-		// Update `uploads.json` in a routine.
 		go func(index int, disk StorageAPI) {
 			defer wg.Done()
-			uploadsJSONBytes, wErr := json.Marshal(&uploadsJSON)
+
+			// read and parse uploads.json on this disk
+			uploadsJSON, err := readUploadsJSON(bucket, object, disk)
+			if errorCause(err) == errFileNotFound {
+				// If file is not found, we assume an
+				// default (empty) upload info.
+				uploadsJSON, err = newUploadsV1("xl"), nil
+			}
+			// If we have a read error, we store error and
+			// exit.
+			if err != nil {
+				errs[index] = traceError(err)
+				return
+			}
+
+			if !uCh.isRemove {
+				// Add the uploadID
+				uploadsJSON.AddUploadID(uCh.uploadID, uCh.initiated)
+			} else {
+				// Remove the upload ID
+				uploadsJSON.RemoveUploadID(uCh.uploadID)
+				if len(uploadsJSON.Uploads) == 0 {
+					isDelete[index] = true
+				}
+			}
+
+			// For delete, rename to tmp, for the
+			// possibility of recovery in case of quorum
+			// failure.
+			if !isDelete[index] {
+				errs[index] = writeUploadJSON(&uploadsJSON, uploadsPath, tmpUploadsPath, disk)
+			} else {
+				wErr := disk.RenameFile(minioMetaBucket, uploadsPath, minioMetaBucket, tmpUploadsPath)
 				if wErr != nil {
 					errs[index] = traceError(wErr)
-				return
 				}
-			// Write `uploads.json` to disk.
+
-			if wErr = disk.AppendFile(minioMetaBucket, tmpUploadsPath, uploadsJSONBytes); wErr != nil {
-				errs[index] = traceError(wErr)
-				return
 			}
-			wErr = disk.RenameFile(minioMetaBucket, tmpUploadsPath, minioMetaBucket, uploadsPath)
-			if wErr != nil {
-				if dErr := disk.DeleteFile(minioMetaBucket, tmpUploadsPath); dErr != nil {
-					errs[index] = traceError(dErr)
-					return
-				}
-				errs[index] = traceError(wErr)
-				return
-			}
-			errs[index] = nil
 		}(index, disk)
 	}
 
-	// Wait here for all the writes to finish.
+	// Wait for all the writes to finish.
 	wg.Wait()
 
-	// Do we have write quorum?.
+	// Do we have write quorum?
 	if !isDiskQuorum(errs, xl.writeQuorum) {
-		// Rename `uploads.json` left over back to tmp location.
+		// No quorum. Perform cleanup on the minority of disks
+		// on which the operation succeeded.
+
+		// There are two cases:
+		//
+		// 1. uploads.json file was updated -> we delete the
+		//    file that we successfully overwrote on the
+		//    minority of disks, so that the failed quorum
+		//    operation is not partially visible.
+		//
+		// 2. uploads.json was deleted -> in this case since
+		//    the delete failed, we restore from tmp.
 		for index, disk := range xl.storageDisks {
-			if disk == nil {
+			if disk == nil || errs[index] != nil {
 				continue
 			}
-			// Undo rename `uploads.json` in parallel.
 			wg.Add(1)
 			go func(index int, disk StorageAPI) {
 				defer wg.Done()
-				if errs[index] != nil {
+				if !isDelete[index] {
-					return
+					_ = disk.DeleteFile(
+						minioMetaBucket,
+						uploadsPath,
+					)
+				} else {
+					_ = disk.RenameFile(
+						minioMetaBucket, tmpUploadsPath,
+						minioMetaBucket, uploadsPath,
+					)
 				}
-				_ = disk.RenameFile(minioMetaBucket, uploadsPath, minioMetaBucket, tmpUploadsPath)
 			}(index, disk)
 		}
 		wg.Wait()
 		return traceError(errXLWriteQuorum)
 	}
 
+	// we do have quorum, so in case of delete upload.json file
+	// operation, we purge from tmp.
+	for index, disk := range xl.storageDisks {
+		if disk == nil || !isDelete[index] {
+			continue
+		}
+		wg.Add(1)
+		go func(index int, disk StorageAPI) {
+			defer wg.Done()
+			// isDelete[index] = true at this point.
+			_ = disk.DeleteFile(minioMetaBucket, tmpUploadsPath)
+		}(index, disk)
+	}
+	wg.Wait()
+
 	// Ignored errors list.
 	ignoredErrs := []error{
 		errDiskNotFound,

cmd/xl-v1-multipart.go

@@ -306,7 +306,7 @@ func (xl xlObjects) newMultipartUpload(bucket string, object string, meta map[st
 
 	initiated := time.Now().UTC()
 	// Create or update 'uploads.json'
-	if err := xl.writeUploadJSON(bucket, object, uploadID, initiated); err != nil {
+	if err := xl.updateUploadJSON(bucket, object, uploadIDChange{uploadID, initiated, false}); err != nil {
 		return "", err
 	}
 	// Return success.
@@ -832,27 +832,8 @@ func (xl xlObjects) CompleteMultipartUpload(bucket string, object string, upload
 	nsMutex.Lock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object), opsID)
 	defer nsMutex.Unlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object), opsID)
 
-	// Validate if there are other incomplete upload-id's present for
+	// remove entry from uploads.json with quorum
-	// the object, if yes do not attempt to delete 'uploads.json'.
+	if err = xl.updateUploadJSON(bucket, object, uploadIDChange{uploadID: uploadID, isRemove: true}); err != nil {
-	uploadsJSON, err := xl.readUploadsJSON(bucket, object)
-	if err != nil {
-		return "", toObjectErr(err, minioMetaBucket, object)
-	}
-	// If we have successfully read `uploads.json`, then we proceed to
-	// purge or update `uploads.json`.
-	uploadIDIdx := uploadsJSON.Index(uploadID)
-	if uploadIDIdx != -1 {
-		uploadsJSON.Uploads = append(uploadsJSON.Uploads[:uploadIDIdx], uploadsJSON.Uploads[uploadIDIdx+1:]...)
-	}
-	if len(uploadsJSON.Uploads) > 0 {
-		if err = xl.updateUploadsJSON(bucket, object, uploadsJSON); err != nil {
-			return "", toObjectErr(err, minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object))
-		}
-		// Return success.
-		return s3MD5, nil
-	} // No more pending uploads for the object, proceed to delete
-	// object completely from '.minio.sys/multipart'.
-	if err = xl.deleteObject(minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object)); err != nil {
 		return "", toObjectErr(err, minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object))
 	}
 
@@ -875,29 +856,11 @@ func (xl xlObjects) abortMultipartUpload(bucket, object, uploadID string) (err e
 
 	nsMutex.Lock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object), opsID)
 	defer nsMutex.Unlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object), opsID)
-	// Validate if there are other incomplete upload-id's present for
+
-	// the object, if yes do not attempt to delete 'uploads.json'.
+	// remove entry from uploads.json with quorum
-	uploadsJSON, err := xl.readUploadsJSON(bucket, object)
+	if err = xl.updateUploadJSON(bucket, object, uploadIDChange{uploadID: uploadID, isRemove: true}); err != nil {
-	if err != nil {
 		return toObjectErr(err, bucket, object)
 	}
-	uploadIDIdx := uploadsJSON.Index(uploadID)
-	if uploadIDIdx != -1 {
-		uploadsJSON.Uploads = append(uploadsJSON.Uploads[:uploadIDIdx], uploadsJSON.Uploads[uploadIDIdx+1:]...)
-	}
-	if len(uploadsJSON.Uploads) > 0 {
-		// There are pending uploads for the same object, preserve
-		// them update 'uploads.json' in-place.
-		err = xl.updateUploadsJSON(bucket, object, uploadsJSON)
-		if err != nil {
-			return toObjectErr(err, bucket, object)
-		}
-		return nil
-	} // No more pending uploads for the object, we purge the entire
-	// entry at '.minio.sys/multipart/bucket/object'.
-	if err = xl.deleteObject(minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object)); err != nil {
-		return toObjectErr(err, minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object))
-	}
 
 	// Successfully purged.
 	return nil