@@ -283,8 +283,27 @@ func scanPriorDrivers(root string) map[string]bool {

 	for driver := range drivers {

 		p := filepath.Join(root, driver)

 		if _, err := os.Stat(p); err == nil && driver != "vfs" {

-			driversMap[driver] = true

+			if !isEmptyDir(p) {

+				driversMap[driver] = true

+			}

 		}

 	}

 	return driversMap

 }

+

+// isEmptyDir checks if a directory is empty. It is used to check if prior

+// storage-driver directories exist. If an error occurs, it also assumes the

+// directory is not empty (which preserves the behavior _before_ this check

+// was added)

+func isEmptyDir(name string) bool {

+	f, err := os.Open(name)

+	if err != nil {

+		return false

+	}

+	defer f.Close()

+

+	if _, err = f.Readdirnames(1); err == io.EOF {

+		return true

+	}

+	return false

+}

new file mode 100644

@@ -0,0 +1,37 @@

+package graphdriver

+

+import (

+	"io/ioutil"

+	"os"

+	"path/filepath"

+	"testing"

+

+	"github.com/stretchr/testify/assert"

+	"github.com/stretchr/testify/require"

+)

+

+func TestIsEmptyDir(t *testing.T) {

+	tmp, err := ioutil.TempDir("", "test-is-empty-dir")

+	require.NoError(t, err)

+	defer os.RemoveAll(tmp)

+

+	d := filepath.Join(tmp, "empty-dir")

+	err = os.Mkdir(d, 0755)

+	require.NoError(t, err)

+	empty := isEmptyDir(d)

+	assert.True(t, empty)

+

+	d = filepath.Join(tmp, "dir-with-subdir")

+	err = os.MkdirAll(filepath.Join(d, "subdir"), 0755)

+	require.NoError(t, err)

+	empty = isEmptyDir(d)

+	assert.False(t, empty)

+

+	d = filepath.Join(tmp, "dir-with-empty-file")

+	err = os.Mkdir(d, 0755)

+	require.NoError(t, err)

+	_, err = ioutil.TempFile(d, "file")

+	require.NoError(t, err)

+	empty = isEmptyDir(d)

+	assert.False(t, empty)

+}