[wallet] Don't hold cs_LastBlockFile while calling setBestChain

cs_LastBlockFile shouldn't be held while calling wallet functions.

src/validation.cpp

@@ -1863,13 +1863,17 @@ static bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockInd
  */
 bool static FlushStateToDisk(const CChainParams& chainparams, CValidationState &state, FlushStateMode mode, int nManualPruneHeight) {
     int64_t nMempoolUsage = mempool.DynamicMemoryUsage();
-    LOCK2(cs_main, cs_LastBlockFile);
+    LOCK(cs_main);
     static int64_t nLastWrite = 0;
     static int64_t nLastFlush = 0;
     static int64_t nLastSetChain = 0;
     std::set<int> setFilesToPrune;
     bool fFlushForPrune = false;
+    bool fDoFullFlush = false;
+    int64_t nNow = 0;
     try {
+    {
+        LOCK(cs_LastBlockFile);
         if (fPruneMode && (fCheckForPruning || nManualPruneHeight > 0) && !fReindex) {
             if (nManualPruneHeight > 0) {
                 FindFilesToPruneManual(setFilesToPrune, nManualPruneHeight);
@@ -1885,7 +1889,7 @@ bool static FlushStateToDisk(const CChainParams& chainparams, CValidationState &
                 }
             }
         }
-    int64_t nNow = GetTimeMicros();
+        nNow = GetTimeMicros();
         // Avoid writing/flushing immediately after startup.
         if (nLastWrite == 0) {
             nLastWrite = nNow;
@@ -1908,7 +1912,7 @@ bool static FlushStateToDisk(const CChainParams& chainparams, CValidationState &
         // It's been very long since we flushed the cache. Do this infrequently, to optimize cache usage.
         bool fPeriodicFlush = mode == FLUSH_STATE_PERIODIC && nNow > nLastFlush + (int64_t)DATABASE_FLUSH_INTERVAL * 1000000;
         // Combine all conditions that result in a full cache flush.
-    bool fDoFullFlush = (mode == FLUSH_STATE_ALWAYS) || fCacheLarge || fCacheCritical || fPeriodicFlush || fFlushForPrune;
+        fDoFullFlush = (mode == FLUSH_STATE_ALWAYS) || fCacheLarge || fCacheCritical || fPeriodicFlush || fFlushForPrune;
         // Write blocks and block index to disk.
         if (fDoFullFlush || fPeriodicWrite) {
             // Depend on nMinDiskSpace to ensure we can write block index
@@ -1953,6 +1957,7 @@ bool static FlushStateToDisk(const CChainParams& chainparams, CValidationState &
                 return AbortNode(state, "Failed to write to coin database");
             nLastFlush = nNow;
         }
+    }
     if (fDoFullFlush || ((mode == FLUSH_STATE_ALWAYS || mode == FLUSH_STATE_PERIODIC) && nNow > nLastSetChain + (int64_t)DATABASE_WRITE_INTERVAL * 1000000)) {
         // Update best block in wallet (so we can detect restored wallets).
         GetMainSignals().SetBestChain(chainActive.GetLocator());