planner: fix tidb can point update data even if tidb_super_read_only …

…is on (#32547) (#32552)

* cherry pick #32547 to release-5.4

Signed-off-by: ti-srebot <ti-srebot@pingcap.com>

planner/optimize.go

@@ -98,6 +98,16 @@ func matchSQLBinding(sctx sessionctx.Context, stmtNode ast.StmtNode) (bindRecord
 func Optimize(ctx context.Context, sctx sessionctx.Context, node ast.Node, is infoschema.InfoSchema) (plannercore.Plan, types.NameSlice, error) {
 	sessVars := sctx.GetSessionVars()
 
+	if !sctx.GetSessionVars().InRestrictedSQL && (variable.RestrictedReadOnly.Load() || variable.VarTiDBSuperReadOnly.Load()) {
+		allowed, err := allowInReadOnlyMode(sctx, node)
+		if err != nil {
+			return nil, nil, err
+		}
+		if !allowed {
+			return nil, nil, errors.Trace(core.ErrSQLInReadOnlyMode)
+		}
+	}
+
 	// Because for write stmt, TiFlash has a different results when lock the data in point get plan. We ban the TiFlash
 	// engine in not read only stmt.
 	if _, isolationReadContainTiFlash := sessVars.IsolationReadEngines[kv.TiFlash]; isolationReadContainTiFlash && !IsReadOnly(node, sessVars) {
@@ -346,16 +356,6 @@ func optimize(ctx context.Context, sctx sessionctx.Context, node ast.Node, is in
 		return nil, nil, 0, err
 	}
 
-	if !sctx.GetSessionVars().InRestrictedSQL && variable.RestrictedReadOnly.Load() || variable.VarTiDBSuperReadOnly.Load() {
-		allowed, err := allowInReadOnlyMode(sctx, node)
-		if err != nil {
-			return nil, nil, 0, err
-		}
-		if !allowed {
-			return nil, nil, 0, errors.Trace(core.ErrSQLInReadOnlyMode)
-		}
-	}
-
 	// Handle the execute statement.
 	if execPlan, ok := p.(*plannercore.Execute); ok {
 		err := execPlan.OptimizePreparedPlan(ctx, sctx, is)

tests/readonlytest/readonly_test.go

@@ -28,8 +28,8 @@ import (
 
 var (
 	tidbRootPassword       = flag.String("passwd", "", "tidb root password")
-	tidbAPort              = flag.Int("tidb_a_port", 4000, "first tidb server listening port")
-	tidbBPort              = flag.Int("tidb_b_port", 4001, "second tidb server listening port")
+	tidbAPort              = flag.Int("tidb_a_port", 4001, "first tidb server listening port")
+	tidbBPort              = flag.Int("tidb_b_port", 4002, "second tidb server listening port")
 	ReadOnlyErrMsg         = "Error 1836: Running in read-only mode"
 	ConflictErrMsg         = "Error 1105: can't turn off tidb_super_read_only when tidb_restricted_read_only is on"
 	PriviledgedErrMsg      = "Error 1227: Access denied; you need (at least one of) the SUPER or SYSTEM_VARIABLES_ADMIN privilege(s) for this operation"
@@ -107,8 +107,18 @@ func createReadOnlySuite(t *testing.T) (s *ReadOnlySuite, clean func()) {
 func TestRestriction(t *testing.T) {
 	s, clean := createReadOnlySuite(t)
 	defer clean()
-	setVariable(t, s.db, TiDBRestrictedReadOnly, 1)
 
+	var err error
+	_, err = s.db.Exec("drop table if exists t")
+	require.NoError(t, err)
+	_, err = s.udb.Exec("create table t (a int primary key, b int)")
+	require.NoError(t, err)
+	_, err = s.udb.Exec("insert into t values (1, 1)")
+	require.NoError(t, err)
+	_, err = s.udb.Exec("update t set b = 2 where a = 1")
+	require.NoError(t, err)
+
+	setVariable(t, s.db, TiDBRestrictedReadOnly, 1)
 	time.Sleep(1)
 
 	checkVariable(t, s.udb, TiDBRestrictedReadOnly, true)
@@ -117,7 +127,18 @@ func TestRestriction(t *testing.T) {
 	checkVariable(t, s.rdb, TiDBRestrictedReadOnly, true)
 	checkVariable(t, s.rdb, TiDBSuperReadOnly, true)
 
-	_, err := s.udb.Exec("create table t(a int)")
+	// can't create table
+	_, err = s.udb.Exec("create table t(a int)")
+	require.Error(t, err)
+	require.Equal(t, err.Error(), ReadOnlyErrMsg)
+
+	// can't do point update when tidb_restricted_read_only is on
+	_, err = s.udb.Exec("update t set b = 2 where a = 1")
+	require.Error(t, err)
+	require.Equal(t, err.Error(), ReadOnlyErrMsg)
+
+	// can't insert
+	_, err = s.udb.Exec("insert into t values (2, 3)")
 	require.Error(t, err)
 	require.Equal(t, err.Error(), ReadOnlyErrMsg)