fix: deadlock of mnode if its state changed

source/dnode/mnode/impl/inc/mndInt.h

@@ -87,10 +87,11 @@ typedef struct {
 typedef struct {
   tsem_t   syncSem;
   int64_t  sync;
-  bool     standby;
   SReplica replica;
   int32_t  errCode;
   int32_t  transId;
+  SRWLatch lock;
+  int8_t   standby;
   int8_t   leaderTransferFinish;
 } SSyncMgmt;
 

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

@@ -60,15 +60,19 @@ void mndSyncCommitMsg(struct SSyncFSM *pFsm, const SRpcMsg *pMsg, SFsmCbMeta cbM
     sdbSetApplyInfo(pMnode->pSdb, cbMeta.index, cbMeta.term, cbMeta.lastConfigIndex);
   }
 
+  taosRLockLatch(&pMgmt->lock);
   if (transId <= 0) {
+    taosRUnLockLatch(&pMgmt->lock);
     mError("trans:%d, invalid commit msg", transId);
   } else if (transId == pMgmt->transId) {
+    taosRUnLockLatch(&pMgmt->lock);
     if (pMgmt->errCode != 0) {
       mError("trans:%d, failed to propose since %s", transId, tstrerror(pMgmt->errCode));
     }
     pMgmt->transId = 0;
     tsem_post(&pMgmt->syncSem);
   } else {
+    taosRUnLockLatch(&pMgmt->lock);
     STrans *pTrans = mndAcquireTrans(pMnode, transId);
     if (pTrans != NULL) {
       mDebug("trans:%d, execute in mnode which not leader", transId);
@@ -115,6 +119,7 @@ void mndReConfig(struct SSyncFSM *pFsm, const SRpcMsg *pMsg, SReConfigCbMeta cbM
   mInfo("trans:-1, sync reconfig is proposed, saved:%d code:0x%x, index:%" PRId64 " term:%" PRId64, pMgmt->transId,
         cbMeta.code, cbMeta.index, cbMeta.term);
 
+  taosWLockLatch(&pMgmt->lock);
   if (pMgmt->transId == -1) {
     if (pMgmt->errCode != 0) {
       mError("trans:-1, failed to propose sync reconfig since %s", tstrerror(pMgmt->errCode));
@@ -122,6 +127,7 @@ void mndReConfig(struct SSyncFSM *pFsm, const SRpcMsg *pMsg, SReConfigCbMeta cbM
     pMgmt->transId = 0;
     tsem_post(&pMgmt->syncSem);
   }
+  taosWUnLockLatch(&pMgmt->lock);
 }
 
 int32_t mndSnapshotStartRead(struct SSyncFSM *pFsm, void *pParam, void **ppReader) {
@@ -170,20 +176,24 @@ static void mndBecomeFollower(struct SSyncFSM *pFsm) {
   SMnode *pMnode = pFsm->data;
   mDebug("vgId:1, become follower");
 
+  taosWLockLatch(&pMnode->syncMgmt.lock);
   if (pMnode->syncMgmt.transId != 0) {
     pMnode->syncMgmt.transId = 0;
     tsem_post(&pMnode->syncMgmt.syncSem);
   }
+  taosWUnLockLatch(&pMnode->syncMgmt.lock);
 }
 
 static void mndBecomeLeader(struct SSyncFSM *pFsm) {
   mDebug("vgId:1, become leader");
   SMnode *pMnode = pFsm->data;
 
+  taosWLockLatch(&pMnode->syncMgmt.lock);
   if (pMnode->syncMgmt.transId != 0) {
     pMnode->syncMgmt.transId = 0;
     tsem_post(&pMnode->syncMgmt.syncSem);
   }
+  taosWUnLockLatch(&pMnode->syncMgmt.lock);
 }
 
 SSyncFSM *mndSyncMakeFsm(SMnode *pMnode) {
@@ -210,6 +220,8 @@ SSyncFSM *mndSyncMakeFsm(SMnode *pMnode) {
 
 int32_t mndInitSync(SMnode *pMnode) {
   SSyncMgmt *pMgmt = &pMnode->syncMgmt;
+  taosInitRWLatch(&pMgmt->lock);
+  pMgmt->transId = 0;
 
   SSyncInfo syncInfo = {.vgId = 1, .FpSendMsg = mndSyncSendMsg, .FpEqMsg = mndSyncEqMsg};
   snprintf(syncInfo.path, sizeof(syncInfo.path), "%s%ssync", pMnode->path, TD_DIRSEP);
@@ -262,11 +274,14 @@ int32_t mndSyncPropose(SMnode *pMnode, SSdbRaw *pRaw, int32_t transId) {
   memcpy(req.pCont, pRaw, req.contLen);
 
   pMgmt->errCode = 0;
+  taosWLockLatch(&pMgmt->lock);
   pMgmt->transId = transId;
+  taosWUnLockLatch(&pMgmt->lock);
   mTrace("trans:%d, will be proposed", pMgmt->transId);
 
   const bool isWeak = false;
   int32_t    code = syncPropose(pMgmt->sync, &req, isWeak);
+
   if (code == 0) {
     tsem_wait(&pMgmt->syncSem);
   } else if (code == -1 && terrno == TSDB_CODE_SYN_NOT_LEADER) {
@@ -294,10 +309,12 @@ void mndSyncStart(SMnode *pMnode) {
 }
 
 void mndSyncStop(SMnode *pMnode) {
+  taosWLockLatch(&pMnode->syncMgmt.lock);
   if (pMnode->syncMgmt.transId != 0) {
     pMnode->syncMgmt.transId = 0;
     tsem_post(&pMnode->syncMgmt.syncSem);
   }
+  taosWUnLockLatch(&pMnode->syncMgmt.lock);
 }
 
 bool mndIsMaster(SMnode *pMnode) {