diff --git a/src/validation.cpp b/src/validation.cpp
index babf6f15221..5133d246482 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -1863,95 +1863,100 @@ 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 {
-    if (fPruneMode && (fCheckForPruning || nManualPruneHeight > 0) && !fReindex) {
-        if (nManualPruneHeight > 0) {
-            FindFilesToPruneManual(setFilesToPrune, nManualPruneHeight);
-        } else {
-            FindFilesToPrune(setFilesToPrune, chainparams.PruneAfterHeight());
-            fCheckForPruning = false;
-        }
-        if (!setFilesToPrune.empty()) {
-            fFlushForPrune = true;
-            if (!fHavePruned) {
-                pblocktree->WriteFlag("prunedblockfiles", true);
-                fHavePruned = true;
-            }
-        }
-    }
-    int64_t nNow = GetTimeMicros();
-    // Avoid writing/flushing immediately after startup.
-    if (nLastWrite == 0) {
-        nLastWrite = nNow;
-    }
-    if (nLastFlush == 0) {
-        nLastFlush = nNow;
-    }
-    if (nLastSetChain == 0) {
-        nLastSetChain = nNow;
-    }
-    int64_t nMempoolSizeMax = GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000;
-    int64_t cacheSize = pcoinsTip->DynamicMemoryUsage();
-    int64_t nTotalSpace = nCoinCacheUsage + std::max<int64_t>(nMempoolSizeMax - nMempoolUsage, 0);
-    // The cache is large and we're within 10% and 10 MiB of the limit, but we have time now (not in the middle of a block processing).
-    bool fCacheLarge = mode == FLUSH_STATE_PERIODIC && cacheSize > std::max((9 * nTotalSpace) / 10, nTotalSpace - MAX_BLOCK_COINSDB_USAGE * 1024 * 1024);
-    // The cache is over the limit, we have to write now.
-    bool fCacheCritical = mode == FLUSH_STATE_IF_NEEDED && cacheSize > nTotalSpace;
-    // It's been a while since we wrote the block index to disk. Do this frequently, so we don't need to redownload after a crash.
-    bool fPeriodicWrite = mode == FLUSH_STATE_PERIODIC && nNow > nLastWrite + (int64_t)DATABASE_WRITE_INTERVAL * 1000000;
-    // 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;
-    // Write blocks and block index to disk.
-    if (fDoFullFlush || fPeriodicWrite) {
-        // Depend on nMinDiskSpace to ensure we can write block index
-        if (!CheckDiskSpace(0))
-            return state.Error("out of disk space");
-        // First make sure all block and undo data is flushed to disk.
-        FlushBlockFile();
-        // Then update all block file information (which may refer to block and undo files).
-        {
-            std::vector<std::pair<int, const CBlockFileInfo*> > vFiles;
-            vFiles.reserve(setDirtyFileInfo.size());
-            for (std::set<int>::iterator it = setDirtyFileInfo.begin(); it != setDirtyFileInfo.end(); ) {
-                vFiles.push_back(std::make_pair(*it, &vinfoBlockFile[*it]));
-                setDirtyFileInfo.erase(it++);
+    {
+        LOCK(cs_LastBlockFile);
+        if (fPruneMode && (fCheckForPruning || nManualPruneHeight > 0) && !fReindex) {
+            if (nManualPruneHeight > 0) {
+                FindFilesToPruneManual(setFilesToPrune, nManualPruneHeight);
+            } else {
+                FindFilesToPrune(setFilesToPrune, chainparams.PruneAfterHeight());
+                fCheckForPruning = false;
             }
-            std::vector<const CBlockIndex*> vBlocks;
-            vBlocks.reserve(setDirtyBlockIndex.size());
-            for (std::set<CBlockIndex*>::iterator it = setDirtyBlockIndex.begin(); it != setDirtyBlockIndex.end(); ) {
-                vBlocks.push_back(*it);
-                setDirtyBlockIndex.erase(it++);
+            if (!setFilesToPrune.empty()) {
+                fFlushForPrune = true;
+                if (!fHavePruned) {
+                    pblocktree->WriteFlag("prunedblockfiles", true);
+                    fHavePruned = true;
+                }
             }
-            if (!pblocktree->WriteBatchSync(vFiles, nLastBlockFile, vBlocks)) {
-                return AbortNode(state, "Failed to write to block index database");
+        }
+        nNow = GetTimeMicros();
+        // Avoid writing/flushing immediately after startup.
+        if (nLastWrite == 0) {
+            nLastWrite = nNow;
+        }
+        if (nLastFlush == 0) {
+            nLastFlush = nNow;
+        }
+        if (nLastSetChain == 0) {
+            nLastSetChain = nNow;
+        }
+        int64_t nMempoolSizeMax = GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000;
+        int64_t cacheSize = pcoinsTip->DynamicMemoryUsage();
+        int64_t nTotalSpace = nCoinCacheUsage + std::max<int64_t>(nMempoolSizeMax - nMempoolUsage, 0);
+        // The cache is large and we're within 10% and 10 MiB of the limit, but we have time now (not in the middle of a block processing).
+        bool fCacheLarge = mode == FLUSH_STATE_PERIODIC && cacheSize > std::max((9 * nTotalSpace) / 10, nTotalSpace - MAX_BLOCK_COINSDB_USAGE * 1024 * 1024);
+        // The cache is over the limit, we have to write now.
+        bool fCacheCritical = mode == FLUSH_STATE_IF_NEEDED && cacheSize > nTotalSpace;
+        // It's been a while since we wrote the block index to disk. Do this frequently, so we don't need to redownload after a crash.
+        bool fPeriodicWrite = mode == FLUSH_STATE_PERIODIC && nNow > nLastWrite + (int64_t)DATABASE_WRITE_INTERVAL * 1000000;
+        // 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.
+        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
+            if (!CheckDiskSpace(0))
+                return state.Error("out of disk space");
+            // First make sure all block and undo data is flushed to disk.
+            FlushBlockFile();
+            // Then update all block file information (which may refer to block and undo files).
+            {
+                std::vector<std::pair<int, const CBlockFileInfo*> > vFiles;
+                vFiles.reserve(setDirtyFileInfo.size());
+                for (std::set<int>::iterator it = setDirtyFileInfo.begin(); it != setDirtyFileInfo.end(); ) {
+                    vFiles.push_back(std::make_pair(*it, &vinfoBlockFile[*it]));
+                    setDirtyFileInfo.erase(it++);
+                }
+                std::vector<const CBlockIndex*> vBlocks;
+                vBlocks.reserve(setDirtyBlockIndex.size());
+                for (std::set<CBlockIndex*>::iterator it = setDirtyBlockIndex.begin(); it != setDirtyBlockIndex.end(); ) {
+                    vBlocks.push_back(*it);
+                    setDirtyBlockIndex.erase(it++);
+                }
+                if (!pblocktree->WriteBatchSync(vFiles, nLastBlockFile, vBlocks)) {
+                    return AbortNode(state, "Failed to write to block index database");
+                }
             }
+            // Finally remove any pruned files
+            if (fFlushForPrune)
+                UnlinkPrunedFiles(setFilesToPrune);
+            nLastWrite = nNow;
+        }
+        // Flush best chain related state. This can only be done if the blocks / block index write was also done.
+        if (fDoFullFlush) {
+            // Typical Coin structures on disk are around 48 bytes in size.
+            // Pushing a new one to the database can cause it to be written
+            // twice (once in the log, and once in the tables). This is already
+            // an overestimation, as most will delete an existing entry or
+            // overwrite one. Still, use a conservative safety factor of 2.
+            if (!CheckDiskSpace(48 * 2 * 2 * pcoinsTip->GetCacheSize()))
+                return state.Error("out of disk space");
+            // Flush the chainstate (which may refer to block index entries).
+            if (!pcoinsTip->Flush())
+                return AbortNode(state, "Failed to write to coin database");
+            nLastFlush = nNow;
         }
-        // Finally remove any pruned files
-        if (fFlushForPrune)
-            UnlinkPrunedFiles(setFilesToPrune);
-        nLastWrite = nNow;
-    }
-    // Flush best chain related state. This can only be done if the blocks / block index write was also done.
-    if (fDoFullFlush) {
-        // Typical Coin structures on disk are around 48 bytes in size.
-        // Pushing a new one to the database can cause it to be written
-        // twice (once in the log, and once in the tables). This is already
-        // an overestimation, as most will delete an existing entry or
-        // overwrite one. Still, use a conservative safety factor of 2.
-        if (!CheckDiskSpace(48 * 2 * 2 * pcoinsTip->GetCacheSize()))
-            return state.Error("out of disk space");
-        // Flush the chainstate (which may refer to block index entries).
-        if (!pcoinsTip->Flush())
-            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).