Merge bitcoin#26331: Implement CCoinsViewErrorCatcher::HaveCoin and…

… check disk space periodically

ed52e71 Periodically check disk space to avoid corruption (Aurèle Oulès)
7fe537f Implement CCoinsViewErrorCatcher::HaveCoin (Aurèle Oulès)

Pull request description:

  Attempt to fix bitcoin#26112.

  As suggested by sipa in bitcoin#26112 (comment):
  > CCoinsViewErrorCatcher, the wrapper class used around CCoinsViewDB that's supposed to detect these problems and forcefully exit the application, has an override for GetCoins. But in CheckTxInputs, HaveInputs is first invoked, which on its turn calls HaveCoin. HaveCoin is implemented in CCoinsViewDB, but not in CCoinsViewErrorCatcher, and thus the disk read exception escapes.
  > A solution may be to just add an override for HaveCoin in CCoinsViewErrorCatcher.

  I implemented `CCoinsViewErrorCatcher::HaveCoin` and also added a periodic disk space check that shutdowns the node if there is not enough space left on disk, the minimum here is 50MB.

  For reviewers, it's possible to saturate disk space to test the PR by creating large files with `fallocate -l 50G test.bin`

ACKs for top commit:
  achow101:
    ACK ed52e71
  w0xlt:
    Code Review ACK bitcoin@ed52e71
  sipa:
    utACK ed52e71

Tree-SHA512: 456aa7b996023df42b4fbb5158ee429d9abf7374b7b1ec129b21aea1188ad19be8da4ae8e0edd90b85b7a3042b8e44e17d3742e33808a4234d5ddbe9bcef1b78

src/coins.cpp

@@ -353,11 +353,13 @@ const Coin& AccessByTxid(const CCoinsViewCache& view, const uint256& txid)
     return coinEmpty;
 }
 
-bool CCoinsViewErrorCatcher::GetCoin(const COutPoint &outpoint, Coin &coin) const {
+template <typename Func>
+static bool ExecuteBackedWrapper(Func func, const std::vector<std::function<void()>>& err_callbacks)
+{
     try {
-        return CCoinsViewBacked::GetCoin(outpoint, coin);
+        return func();
     } catch(const std::runtime_error& e) {
-        for (const auto& f : m_err_callbacks) {
+        for (const auto& f : err_callbacks) {
             f();
         }
         LogPrintf("Error reading from database: %s\n", e.what());
@@ -368,3 +370,11 @@ bool CCoinsViewErrorCatcher::GetCoin(const COutPoint &outpoint, Coin &coin) cons
         std::abort();
     }
 }
+
+bool CCoinsViewErrorCatcher::GetCoin(const COutPoint &outpoint, Coin &coin) const {
+    return ExecuteBackedWrapper([&]() { return CCoinsViewBacked::GetCoin(outpoint, coin); }, m_err_callbacks);
+}
+
+bool CCoinsViewErrorCatcher::HaveCoin(const COutPoint &outpoint) const {
+    return ExecuteBackedWrapper([&]() { return CCoinsViewBacked::HaveCoin(outpoint); }, m_err_callbacks);
+}

src/coins.h

@@ -383,6 +383,7 @@ class CCoinsViewErrorCatcher final : public CCoinsViewBacked
     }
 
     bool GetCoin(const COutPoint &outpoint, Coin &coin) const override;
+    bool HaveCoin(const COutPoint &outpoint) const override;
 
 private:
     /** A list of callbacks to execute upon leveldb read error. */

src/init.cpp

@@ -1138,6 +1138,15 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
         RandAddPeriodic();
     }, std::chrono::minutes{1});
 
+    // Check disk space every 5 minutes to avoid db corruption.
+    node.scheduler->scheduleEvery([&args]{
+        constexpr uint64_t min_disk_space = 50 << 20; // 50 MB
+        if (!CheckDiskSpace(args.GetBlocksDirPath(), min_disk_space)) {
+            LogPrintf("Shutting down due to lack of disk space!\n");
+            StartShutdown();
+        }
+    }, std::chrono::minutes{5});
+
     GetMainSignals().RegisterBackgroundSignalScheduler(*node.scheduler);
 
     // Create client interfaces for wallets that are supposed to be loaded