rbd: add GroupSnapRollback implementing rbd_group_snap_rollback

* Add GroupSnapRollback implementing rbd_group_snap_rollback

Adds tests for the above.

Signed-off-by: John Mulligan <jmulligan@redhat.com>

rbd/group_snap.go

@@ -130,3 +130,20 @@ func GroupSnapList(ioctx *rados.IOContext, group string) ([]GroupSnapInfo, error
 		cSize)
 	return snaps, getError(ret)
 }
+
+// GroupSnapRollback will roll back the images in the group to that of the
+// given snapshot.
+//
+// Implements:
+//  int rbd_group_snap_rollback(rados_ioctx_t group_p,
+//                              const char *group_name,
+//                              const char *snap_name);
+func GroupSnapRollback(ioctx *rados.IOContext, group, snap string) error {
+	cGroupName := C.CString(group)
+	defer C.free(unsafe.Pointer(cGroupName))
+	cSnapName := C.CString(snap)
+	defer C.free(unsafe.Pointer(cSnapName))
+
+	ret := C.rbd_group_snap_rollback(cephIoctx(ioctx), cGroupName, cSnapName)
+	return getError(ret)
+}

rbd/group_snap_test.go

@@ -104,6 +104,56 @@ func TestGroupSnapshots(t *testing.T) {
 		assert.NoError(t, err)
 		assert.Len(t, gsl, 0)
 	})
+	t.Run("groupSnapRollback", func(t *testing.T) {
+		img, err := OpenImage(ioctx, name1, NoSnapshot)
+		assert.NoError(t, err)
+		_, err = img.WriteAt([]byte("HELLO WORLD"), 0)
+		assert.NoError(t, err)
+		err = img.Close()
+		assert.NoError(t, err)
+
+		snapname := "snap1"
+		err = GroupSnapCreate(ioctx, gname, snapname)
+		assert.NoError(t, err)
+
+		img, err = OpenImage(ioctx, name1, NoSnapshot)
+		assert.NoError(t, err)
+		_, err = img.WriteAt([]byte("GOODBYE WORLD"), 0)
+		assert.NoError(t, err)
+		err = img.Close()
+		assert.NoError(t, err)
+
+		img, err = OpenImage(ioctx, name2, NoSnapshot)
+		assert.NoError(t, err)
+		_, err = img.WriteAt([]byte("2222222222222"), 0)
+		assert.NoError(t, err)
+		err = img.Close()
+		assert.NoError(t, err)
+
+		err = GroupSnapRollback(ioctx, gname, snapname)
+		assert.NoError(t, err)
+
+		b := make([]byte, 8)
+		img, err = OpenImage(ioctx, name1, NoSnapshot)
+		assert.NoError(t, err)
+		_, err = img.ReadAt(b, 0)
+		assert.NoError(t, err)
+		err = img.Close()
+		assert.NoError(t, err)
+		assert.Equal(t, []byte("HELLO WO"), b)
+
+		img, err = OpenImage(ioctx, name2, NoSnapshot)
+		assert.NoError(t, err)
+		_, err = img.ReadAt(b, 0)
+		assert.NoError(t, err)
+		err = img.Close()
+		assert.NoError(t, err)
+		assert.Equal(t, []byte("\x00\x00\x00\x00\x00\x00\x00\x00"), b)
+
+		err = GroupSnapRemove(ioctx, gname, snapname)
+		assert.NoError(t, err)
+	})
+	})
 	t.Run("invalidIOContext", func(t *testing.T) {
 		assert.Panics(t, func() {
 			GroupSnapCreate(nil, gname, "foo")
@@ -117,5 +167,8 @@ func TestGroupSnapshots(t *testing.T) {
 		assert.Panics(t, func() {
 			GroupSnapList(nil, gname)
 		})
+		assert.Panics(t, func() {
+			GroupSnapRollback(nil, gname, "foo")
+		})
 	})
 }