From cf4aa65316263513b3be9143b0a5e498af2a1ed6 Mon Sep 17 00:00:00 2001
From: moneromooo-monero <moneromooo-monero@users.noreply.github.com>
Date: Tue, 29 Aug 2017 15:43:32 +0100
Subject: [PATCH] Fix blockchain_import wedge on exception in
 cleanup_handle_incoming_blocks

---
 src/blockchain_db/lmdb/db_lmdb.cpp            | 31 +++++++++++++------
 src/blockchain_db/lmdb/db_lmdb.h              |  3 ++
 .../blockchain_import.cpp                     |  6 +++-
 src/cryptonote_core/blockchain.cpp            | 17 ++++++++--
 src/cryptonote_core/cryptonote_core.cpp       |  5 +--
 5 files changed, 47 insertions(+), 15 deletions(-)

diff --git a/src/blockchain_db/lmdb/db_lmdb.cpp b/src/blockchain_db/lmdb/db_lmdb.cpp
index 4100d9cc..b6978bdc 100644
--- a/src/blockchain_db/lmdb/db_lmdb.cpp
+++ b/src/blockchain_db/lmdb/db_lmdb.cpp
@@ -2604,6 +2604,16 @@ void BlockchainLMDB::batch_commit()
   memset(&m_wcursors, 0, sizeof(m_wcursors));
 }
 
+void BlockchainLMDB::cleanup_batch()
+{
+  // for destruction of batch transaction
+  m_write_txn = nullptr;
+  delete m_write_batch_txn;
+  m_write_batch_txn = nullptr;
+  m_batch_active = false;
+  memset(&m_wcursors, 0, sizeof(m_wcursors));
+}
+
 void BlockchainLMDB::batch_stop()
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
@@ -2618,15 +2628,18 @@ void BlockchainLMDB::batch_stop()
   check_open();
   LOG_PRINT_L3("batch transaction: committing...");
   TIME_MEASURE_START(time1);
-  m_write_txn->commit();
-  TIME_MEASURE_FINISH(time1);
-  time_commit1 += time1;
-  // for destruction of batch transaction
-  m_write_txn = nullptr;
-  delete m_write_batch_txn;
-  m_write_batch_txn = nullptr;
-  m_batch_active = false;
-  memset(&m_wcursors, 0, sizeof(m_wcursors));
+  try
+  {
+    m_write_txn->commit();
+    TIME_MEASURE_FINISH(time1);
+    time_commit1 += time1;
+    cleanup_batch();
+  }
+  catch (const std::exception &e)
+  {
+    cleanup_batch();
+    throw;
+  }
   LOG_PRINT_L3("batch transaction: end");
 }
 
diff --git a/src/blockchain_db/lmdb/db_lmdb.h b/src/blockchain_db/lmdb/db_lmdb.h
index 3a11ddf0..90274b90 100644
--- a/src/blockchain_db/lmdb/db_lmdb.h
+++ b/src/blockchain_db/lmdb/db_lmdb.h
@@ -368,6 +368,9 @@ private:
   // migrate from DB version 0 to 1
   void migrate_0_1();
 
+  void cleanup_batch();
+
+private:
   MDB_env* m_env;
 
   MDB_dbi m_blocks;
diff --git a/src/blockchain_utilities/blockchain_import.cpp b/src/blockchain_utilities/blockchain_import.cpp
index ded854ca..14f31876 100644
--- a/src/blockchain_utilities/blockchain_import.cpp
+++ b/src/blockchain_utilities/blockchain_import.cpp
@@ -208,7 +208,8 @@ int check_flush(cryptonote::core &core, std::list<block_complete_entry> &blocks,
     }
 
   } // each download block
-  core.cleanup_handle_incoming_blocks();
+  if (!core.cleanup_handle_incoming_blocks())
+    return 1;
 
   blocks.clear();
   return 0;
@@ -394,7 +395,10 @@ int import_from_file(cryptonote::core& core, const std::string& import_file_path
           blocks.push_back({block, txs});
           int ret = check_flush(core, blocks, false);
           if (ret)
+          {
+            quit = 2; // make sure we don't commit partial block data
             break;
+          }
         }
         else
         {
diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
index c1faa703..93a4e26f 100644
--- a/src/cryptonote_core/blockchain.cpp
+++ b/src/cryptonote_core/blockchain.cpp
@@ -3582,12 +3582,23 @@ void Blockchain::block_longhash_worker(uint64_t height, const std::vector<block>
 //------------------------------------------------------------------
 bool Blockchain::cleanup_handle_incoming_blocks(bool force_sync)
 {
+  bool success = false;
+
   MTRACE("Blockchain::" << __func__);
   CRITICAL_REGION_BEGIN(m_blockchain_lock);
   TIME_MEASURE_START(t1);
 
-  m_db->batch_stop();
-  if (m_sync_counter > 0)
+  try
+  {
+    m_db->batch_stop();
+    success = true;
+  }
+  catch (const std::exception &e)
+  {
+    MERROR("Exception in cleanup_handle_incoming_blocks: " << e.what());
+  }
+
+  if (success && m_sync_counter > 0)
   {
     if (force_sync)
     {
@@ -3622,7 +3633,7 @@ bool Blockchain::cleanup_handle_incoming_blocks(bool force_sync)
   CRITICAL_REGION_END();
   m_tx_pool.unlock();
 
-  return true;
+  return success;
 }
 
 //------------------------------------------------------------------
diff --git a/src/cryptonote_core/cryptonote_core.cpp b/src/cryptonote_core/cryptonote_core.cpp
index af0616af..ac157906 100644
--- a/src/cryptonote_core/cryptonote_core.cpp
+++ b/src/cryptonote_core/cryptonote_core.cpp
@@ -1068,12 +1068,13 @@ namespace cryptonote
   //-----------------------------------------------------------------------------------------------
   bool core::cleanup_handle_incoming_blocks(bool force_sync)
   {
+    bool success = false;
     try {
-      m_blockchain_storage.cleanup_handle_incoming_blocks(force_sync);
+      success = m_blockchain_storage.cleanup_handle_incoming_blocks(force_sync);
     }
     catch (...) {}
     m_incoming_tx_lock.unlock();
-    return true;
+    return success;
   }
 
   //-----------------------------------------------------------------------------------------------