Moving os.MkdirAll() inside atomic for auto parent directory creates

pkg/donut/disk/disk.go

@@ -153,13 +153,7 @@ func (disk Disk) CreateFile(filename string) (*atomic.File, error) {
 		return nil, iodine.New(InvalidArgument{}, nil)
 	}
 
-	filePath := filepath.Join(disk.path, filename)
+	f, err := atomic.FileCreate(filepath.Join(disk.path, filename))
-	// Create directories if they don't exist
-	if err := os.MkdirAll(filepath.Dir(filePath), 0700); err != nil {
-		return nil, iodine.New(err, nil)
-	}
-
-	f, err := atomic.FileCreate(filePath)
 	if err != nil {
 		return nil, iodine.New(err, nil)
 	}

pkg/utils/atomic/atomic.go

@@ -58,8 +58,13 @@ func (f *File) CloseAndPurge() error {
 	return nil
 }
 
-// FileCreate creates a new file at filePath for atomic writes
+// FileCreate creates a new file at filePath for atomic writes, it also creates parent directories if they don't exist
 func FileCreate(filePath string) (*File, error) {
+	// if parent directories do not exist, ioutil.TempFile doesn't create them
+	// handle such a case with os.MkdirAll()
+	if err := os.MkdirAll(filepath.Dir(filePath), 0700); err != nil {
+		return nil, iodine.New(err, nil)
+	}
 	f, err := ioutil.TempFile(filepath.Dir(filePath), filepath.Base(filePath))
 	if err != nil {
 		return nil, iodine.New(err, nil)