From 4df91b3ab9bb1c5af4befce19d7b462e8b5dff02 Mon Sep 17 00:00:00 2001
From: tiancaiamao <tiancaiamao@gmail.com>
Date: Thu, 5 Dec 2024 10:22:14 +0800
Subject: [PATCH] *: avoid unlock of unlocked mutex panic on TableDeltaMap
 (#57799)

close pingcap/tidb#57798
---
 pkg/sessionctx/variable/session.go | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pkg/sessionctx/variable/session.go b/pkg/sessionctx/variable/session.go
index e7bc825cb36f3..1307feba252c8 100644
--- a/pkg/sessionctx/variable/session.go
+++ b/pkg/sessionctx/variable/session.go
@@ -3553,8 +3553,9 @@ func (s *SessionVars) GetNegateStrMatchDefaultSelectivity() float64 {
 
 // GetRelatedTableForMDL gets the related table for metadata lock.
 func (s *SessionVars) GetRelatedTableForMDL() *sync.Map {
-	s.TxnCtx.tdmLock.Lock()
-	defer s.TxnCtx.tdmLock.Unlock()
+	mu := &s.TxnCtx.tdmLock
+	mu.Lock()
+	defer mu.Unlock()
 	if s.TxnCtx.relatedTableForMDL == nil {
 		s.TxnCtx.relatedTableForMDL = new(sync.Map)
 	}