fix(query): new META_READER_NOLOCK flag for metaReaderInit

source/dnode/vnode/inc/vnode.h

@@ -91,6 +91,8 @@ typedef struct SMeta       SMeta;  // todo: remove
 typedef struct SMetaReader SMetaReader;
 typedef struct SMetaEntry  SMetaEntry;
 
+#define META_READER_NOLOCK 0x1
+
 void        metaReaderInit(SMetaReader *pReader, SMeta *pMeta, int32_t flags);
 void        metaReaderClear(SMetaReader *pReader);
 int32_t     metaGetTableEntryByUid(SMetaReader *pReader, tb_uid_t uid);

source/dnode/vnode/src/meta/metaQuery.c

@@ -19,11 +19,13 @@ void metaReaderInit(SMetaReader *pReader, SMeta *pMeta, int32_t flags) {
   memset(pReader, 0, sizeof(*pReader));
   pReader->flags = flags;
   pReader->pMeta = pMeta;
+  if (!(flags & META_READER_NOLOCK)) {
     metaRLock(pMeta);
+  }
 }
 
 void metaReaderClear(SMetaReader *pReader) {
-  if (pReader->pMeta) {
+  if (pReader->pMeta && !(pReader->flags & META_READER_NOLOCK)) {
     metaULock(pReader->pMeta);
   }
   tDecoderClear(&pReader->coder);

source/libs/executor/src/scanoperator.c

@@ -2757,7 +2757,7 @@ static SSDataBlock* sysTableScanUserTables(SOperatorInfo* pOperator) {
         colDataAppend(pColInfoData, numOfRows, (char*)&ts, false);
 
         SMetaReader mr = {0};
-        metaReaderInit(&mr, pInfo->readHandle.meta, 0);
+        metaReaderInit(&mr, pInfo->readHandle.meta, META_READER_NOLOCK);
 
         uint64_t suid = pInfo->pCur->mr.me.ctbEntry.suid;
         int32_t  code = metaGetTableEntryByUid(&mr, suid);