br: skip fresh check when user has specified --filter in restore full (…

…#51010)

close #51009

br/pkg/restore/client.go

@@ -1154,6 +1154,11 @@ func (rc *Client) createTablesInWorkerPool(ctx context.Context, dom *domain.Doma
 	return eg.Wait()
 }
 
+// NeedCheckFreshCluster is every time. except restore from a checkpoint or user has not set filter argument.
+func (rc *Client) NeedCheckFreshCluster(ExplicitFilter bool, firstRun bool) bool {
+	return rc.IsFull() && !ExplicitFilter && firstRun
+}
+
 // CheckTargetClusterFresh check whether the target cluster is fresh or not
 // if there's no user dbs or tables, we take it as a fresh cluster, although
 // user may have created some users or made other changes.

br/pkg/restore/client_test.go

@@ -124,6 +124,36 @@ func getStartedMockedCluster(t *testing.T) *mock.Cluster {
 	return cluster
 }
 
+func TestNeedCheckTargetClusterFresh(t *testing.T) {
+	// cannot use shared `mc`, other parallel case may change it.
+	cluster := getStartedMockedCluster(t)
+	defer cluster.Stop()
+
+	g := gluetidb.New()
+	client := restore.NewRestoreClient(cluster.PDClient, cluster.PDHTTPCli, nil, defaultKeepaliveCfg, false)
+	err := client.Init(g, cluster.Storage)
+	require.NoError(t, err)
+
+	// not set filter and first run with checkpoint
+	require.True(t, client.NeedCheckFreshCluster(false, true))
+
+	// skip check when has checkpoint
+	require.False(t, client.NeedCheckFreshCluster(false, false))
+
+	// skip check when set --filter
+	require.False(t, client.NeedCheckFreshCluster(true, false))
+
+	// skip check when has set --filter and has checkpoint
+	require.False(t, client.NeedCheckFreshCluster(true, true))
+
+	require.NoError(t, failpoint.Enable("github.com/pingcap/tidb/br/pkg/restore/mock-incr-backup-data", "return(false)"))
+	defer func() {
+		require.NoError(t, failpoint.Disable("github.com/pingcap/tidb/br/pkg/restore/mock-incr-backup-data"))
+	}()
+	// skip check when increment backup
+	require.False(t, client.NeedCheckFreshCluster(false, true))
+}
+
 func TestCheckTargetClusterFresh(t *testing.T) {
 	// cannot use shared `mc`, other parallel case may change it.
 	cluster := getStartedMockedCluster(t)

br/pkg/task/restore.go

@@ -821,8 +821,7 @@ func runRestore(c context.Context, g glue.Glue, cmdName string, cfg *RestoreConf
 	}
 
 	if isFullRestore(cmdName) {
-		// we need check cluster is fresh every time. except restore from a checkpoint.
-		if client.IsFull() && checkpointFirstRun {
+		if client.NeedCheckFreshCluster(cfg.ExplicitFilter, checkpointFirstRun) {
 			if err = client.CheckTargetClusterFresh(ctx); err != nil {
 				return errors.Trace(err)
 			}