snapshots/devmapper: fix rollback

The rollback mechanism is implemented by calling deleteDevice() and
RemoveDevice(). But RemoveDevice() is internally calling
deleteDevice() as well.

Since a device will be deleted by first deleteDevice(),
RemoveDevice() always will see ENODATA. The specific error must be
ignored to remove the device's metadata correctly.

Signed-off-by: Kazuyoshi Kato <katokazu@amazon.com>

snapshots/devmapper/pool_device_test.go

@@ -152,6 +152,27 @@ func TestPoolDevice(t *testing.T) {
 	t.Run("RemoveDevice", func(t *testing.T) {
 		testRemoveThinDevice(t, pool)
 	})
+
+	t.Run("rollbackActivate", func(t *testing.T) {
+		testCreateThinDevice(t, pool)
+
+		ctx := context.Background()
+
+		snapDevice := "snap2"
+
+		err := pool.CreateSnapshotDevice(ctx, thinDevice1, snapDevice, device1Size)
+		assert.NilError(t, err)
+
+		info, err := pool.metadata.GetDevice(ctx, snapDevice)
+		assert.NilError(t, err)
+
+		// Simulate a case that the device cannot be activated.
+		err = pool.DeactivateDevice(ctx, info.Name, false, false)
+		assert.NilError(t, err)
+
+		err = pool.rollbackActivate(ctx, info, err)
+		assert.NilError(t, err)
+	})
 }
 
 func TestPoolDeviceMarkFaulty(t *testing.T) {
@@ -256,6 +277,9 @@ func testDeactivateThinDevice(t *testing.T, pool *PoolDevice) {
 func testRemoveThinDevice(t *testing.T, pool *PoolDevice) {
 	err := pool.RemoveDevice(testCtx, thinDevice1)
 	assert.NilError(t, err, "should delete thin device from pool")
+
+	err = pool.RemoveDevice(testCtx, thinDevice2)
+	assert.NilError(t, err, "should delete thin device from pool")
 }
 
 func getMounts(thinDeviceName string) []mount.Mount {