fix: deadlock of mnode if its state changed

source/dnode/mnode/impl/src/mndSync.c

@@ -170,12 +170,20 @@ static void mndBecomeFollower(struct SSyncFSM *pFsm) {
   SMnode *pMnode = pFsm->data;
   mDebug("vgId:1, become follower");
 
-  // clear old leader resource
+  if (pMnode->syncMgmt.transId != 0) {
+    pMnode->syncMgmt.transId = 0;
+    tsem_post(&pMnode->syncMgmt.syncSem);
+  }
 }
 
 static void mndBecomeLeader(struct SSyncFSM *pFsm) {
-  SMnode *pMnode = pFsm->data;
   mDebug("vgId:1, become leader");
+  SMnode *pMnode = pFsm->data;
+
+  if (pMnode->syncMgmt.transId != 0) {
+    pMnode->syncMgmt.transId = 0;
+    tsem_post(&pMnode->syncMgmt.syncSem);
+  }
 }
 
 SSyncFSM *mndSyncMakeFsm(SMnode *pMnode) {

tests/script/tsim/show/basic.sim

@@ -210,6 +210,8 @@ if $rows != 3 then
   return -1
 endi
 
+sql_error select * from performance_schema.PERF_OFFSETS;
+
 sql show create stable stb;
 if $rows != 1 then
   return -1