fs: Filter out $multiparts properly.

Relax md5 requirement during complete multipart upload - ref #977

pkg/fs/fs-bucket-listobjects.go

@@ -69,6 +69,9 @@ func (fs Filesystem) ListObjects(bucket string, resources BucketResourcesMetadat
 			return nil, resources, probe.NewError(err)
 		}
 		for _, fl := range files {
+			if strings.HasSuffix(fl.Name(), "$multiparts") {
+				continue
+			}
 			p.files = append(p.files, contentInfo{
 				Prefix:   fl.Name(),
 				Size:     fl.Size(),
@@ -105,6 +108,9 @@ func (fs Filesystem) ListObjects(bucket string, resources BucketResourcesMetadat
 				return nil, resources, probe.NewError(err)
 			}
 			for _, fl := range files {
+				if strings.HasSuffix(fl.Name(), "$multiparts") {
+					continue
+				}
 				prefix := fl.Name()
 				if resources.Prefix != "" {
 					prefix = filepath.Join(resources.Prefix, fl.Name())

pkg/fs/fs-multipart.go

@@ -17,7 +17,6 @@
 package fs
 
 import (
-	"bytes"
 	"crypto/md5"
 	"encoding/base64"
 	"encoding/hex"
@@ -116,28 +115,23 @@ func (fs Filesystem) ListMultipartUploads(bucket string, resources BucketMultipa
 
 func (fs Filesystem) concatParts(parts *CompleteMultipartUpload, objectPath string, mw io.Writer) *probe.Error {
 	for _, part := range parts.Part {
-		recvMD5 := part.ETag
-		partFile, err := os.OpenFile(objectPath+fmt.Sprintf("$%d", part.PartNumber), os.O_RDONLY, 0600)
+		partFile, e := os.OpenFile(objectPath+fmt.Sprintf("$%d-$multiparts", part.PartNumber), os.O_RDONLY, 0600)
 		defer partFile.Close()
-		if err != nil {
-			return probe.NewError(err)
+		if e != nil {
+			return probe.NewError(e)
 		}
-		obj, err := ioutil.ReadAll(partFile)
-		if err != nil {
-			return probe.NewError(err)
-		}
-		calcMD5Bytes := md5.Sum(obj)
-		// complete multi part request header md5sum per part is hex encoded
-		recvMD5Bytes, err := hex.DecodeString(strings.Trim(recvMD5, "\""))
-		if err != nil {
+
+		recvMD5 := part.ETag
+		// complete multipart request header md5sum per part is hex encoded
+		// trim it and decode if possible.
+		_, e = hex.DecodeString(strings.Trim(recvMD5, "\""))
+		if e != nil {
 			return probe.NewError(InvalidDigest{Md5: recvMD5})
 		}
-		if !bytes.Equal(recvMD5Bytes, calcMD5Bytes[:]) {
-			return probe.NewError(BadDigest{Md5: recvMD5})
-		}
-		_, err = io.Copy(mw, bytes.NewBuffer(obj))
-		if err != nil {
-			return probe.NewError(err)
+
+		_, e = io.Copy(mw, partFile)
+		if e != nil {
+			return probe.NewError(e)
 		}
 	}
 	return nil
@@ -275,8 +269,8 @@ func (fs Filesystem) CreateObjectPart(bucket, object, uploadID, expectedMD5Sum s
 	}
 
 	objectPath := filepath.Join(bucketPath, object)
-	partPath := objectPath + fmt.Sprintf("$%d", partID)
-	partFile, err := atomic.FileCreateWithPrefix(partPath, "")
+	partPath := objectPath + fmt.Sprintf("$%d-$multiparts", partID)
+	partFile, err := atomic.FileCreateWithPrefix(partPath, "$multiparts")
 	if err != nil {
 		return "", probe.NewError(err)
 	}
@@ -415,7 +409,7 @@ func (fs Filesystem) CompleteMultipartUpload(bucket, object, uploadID string, da
 
 	delete(fs.multiparts.ActiveSession, object)
 	for _, part := range parts.Part {
-		err = os.Remove(objectPath + fmt.Sprintf("$%d", part.PartNumber))
+		err = os.Remove(objectPath + fmt.Sprintf("$%d-$multiparts", part.PartNumber))
 		if err != nil {
 			file.CloseAndPurge()
 			return ObjectMetadata{}, probe.NewError(err)
@@ -546,7 +540,7 @@ func (fs Filesystem) AbortMultipartUpload(bucket, object, uploadID string) *prob
 
 	objectPath := filepath.Join(bucketPath, object)
 	for _, part := range fs.multiparts.ActiveSession[object].Parts {
-		err = os.RemoveAll(objectPath + fmt.Sprintf("$%d", part.PartNumber))
+		err = os.RemoveAll(objectPath + fmt.Sprintf("$%d-$multiparts", part.PartNumber))
 		if err != nil {
 			return probe.NewError(err)
 		}