Fix volume initialize error check, Fixes #11725

Signed-off-by: Antonio Murdaca <me@runcom.ninja>

volumes/volume.go

@@ -90,7 +90,10 @@ func (v *Volume) initialize() error {
 	v.lock.Lock()
 	defer v.lock.Unlock()
 
-	if _, err := os.Stat(v.Path); err != nil && os.IsNotExist(err) {
+	if _, err := os.Stat(v.Path); err != nil {
+		if !os.IsNotExist(err) {
+			return err
+		}
 		if err := os.MkdirAll(v.Path, 0755); err != nil {
 			return err
 		}

volumes/volume_test.go

@@ -1,6 +1,11 @@
 package volumes
 
-import "testing"
+import (
+	"strings"
+	"testing"
+
+	"github.com/docker/docker/pkg/stringutils"
+)
 
 func TestContainers(t *testing.T) {
 	v := &Volume{containers: make(map[string]struct{})}
@@ -17,3 +22,34 @@ func TestContainers(t *testing.T) {
 		t.Fatalf("removing container failed")
 	}
 }
+
+// os.Stat(v.Path) is returning ErrNotExist, initialize catch it and try to
+// mkdir v.Path but it dies and correctly returns the error
+func TestInitializeCannotMkdirOnNonExistentPath(t *testing.T) {
+	v := &Volume{Path: "nonexistentpath"}
+
+	err := v.initialize()
+	if err == nil {
+		t.Fatal("Expected not to initialize volume with a non existent path")
+	}
+
+	if !strings.Contains(err.Error(), "mkdir : no such file or directory") {
+		t.Fatalf("Expected to get mkdir no such file or directory, got %s", err)
+	}
+}
+
+// os.Stat(v.Path) is NOT returning ErrNotExist so skip and return error from
+// initialize
+func TestInitializeCannotStatPathFileNameTooLong(t *testing.T) {
+	// ENAMETOOLONG
+	v := &Volume{Path: stringutils.GenerateRandomAlphaOnlyString(300)}
+
+	err := v.initialize()
+	if err == nil {
+		t.Fatal("Expected not to initialize volume with a non existent path")
+	}
+
+	if !strings.Contains(err.Error(), "file name too long") {
+		t.Fatalf("Expected to get ENAMETOOLONG error, got %s", err)
+	}
+}