xl: Avoid removing a directory if it is not an object dir (#6395)

DeleteObject should not remove any directory unless the latter
is an empty directory.

Fixes #6394

cmd/xl-v1-object.go

@@ -843,24 +843,27 @@ func (xl xlObjects) DeleteObject(ctx context.Context, bucket, object string) (er
 		return err
 	}
 
-	if hasSuffix(object, slashSeparator) {
-		// Delete the object on all disks.
-		if err = xl.deleteObject(ctx, bucket, object, len(xl.getDisks())/2+1, true); err != nil {
-			return toObjectErr(err, bucket, object)
-		}
+	if !xl.isObject(bucket, object) {
+		return ObjectNotFound{bucket, object}
 	}
 
-	// Read metadata associated with the object from all disks.
-	partsMetadata, errs := readAllXLMetadata(ctx, xl.getDisks(), bucket, object)
+	var writeQuorum int
+	var isObjectDir = hasSuffix(object, slashSeparator)
 
-	// get Quorum for this object
-	_, writeQuorum, err := objectQuorumFromMeta(ctx, xl, partsMetadata, errs)
-	if err != nil {
-		return toObjectErr(err, bucket, object)
+	if isObjectDir {
+		writeQuorum = len(xl.getDisks())/2 + 1
+	} else {
+		// Read metadata associated with the object from all disks.
+		partsMetadata, errs := readAllXLMetadata(ctx, xl.getDisks(), bucket, object)
+		// get Quorum for this object
+		_, writeQuorum, err = objectQuorumFromMeta(ctx, xl, partsMetadata, errs)
+		if err != nil {
+			return toObjectErr(err, bucket, object)
+		}
 	}
 
 	// Delete the object on all disks.
-	if err = xl.deleteObject(ctx, bucket, object, writeQuorum, false); err != nil {
+	if err = xl.deleteObject(ctx, bucket, object, writeQuorum, isObjectDir); err != nil {
 		return toObjectErr(err, bucket, object)
 	}
 

cmd/xl-v1-object_test.go

@@ -71,11 +71,14 @@ func TestXLDeleteObjectBasic(t *testing.T) {
 		object      string
 		expectedErr error
 	}{
-		{".test", "obj", BucketNameInvalid{Bucket: ".test"}},
-		{"----", "obj", BucketNameInvalid{Bucket: "----"}},
+		{".test", "dir/obj", BucketNameInvalid{Bucket: ".test"}},
+		{"----", "dir/obj", BucketNameInvalid{Bucket: "----"}},
 		{"bucket", "", ObjectNameInvalid{Bucket: "bucket", Object: ""}},
 		{"bucket", "doesnotexist", ObjectNotFound{Bucket: "bucket", Object: "doesnotexist"}},
-		{"bucket", "obj", nil},
+		{"bucket", "dir/doesnotexist", ObjectNotFound{Bucket: "bucket", Object: "dir/doesnotexist"}},
+		{"bucket", "dir", ObjectNotFound{Bucket: "bucket", Object: "dir"}},
+		{"bucket", "dir/", ObjectNotFound{Bucket: "bucket", Object: "dir/"}},
+		{"bucket", "dir/obj", nil},
 	}
 
 	// Create an instance of xl backend
@@ -84,14 +87,13 @@ func TestXLDeleteObjectBasic(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	// Make bucket for Test 7 to pass
 	err = xl.MakeBucketWithLocation(context.Background(), "bucket", "")
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	// Create object "obj" under bucket "bucket" for Test 7 to pass
-	_, err = xl.PutObject(context.Background(), "bucket", "obj", mustGetHashReader(t, bytes.NewReader([]byte("abcd")), int64(len("abcd")), "", ""), nil)
+	// Create object "dir/obj" under bucket "bucket" for Test 7 to pass
+	_, err = xl.PutObject(context.Background(), "bucket", "dir/obj", mustGetHashReader(t, bytes.NewReader([]byte("abcd")), int64(len("abcd")), "", ""), nil)
 	if err != nil {
 		t.Fatalf("XL Object upload failed: <ERROR> %s", err)
 	}