Merge bitcoin/bitcoin#30428: log: LogError with FlatFilePos in UndoReadFromDisk

fa14e1d9d5c5dc44396a01583ae94480b7bc29ee log: Fix __func__ in LogError in blockstorage module (MarcoFalke)
fad59a2f0f37f5b7f6076fd91be43448e35f4b7e log: LogError with FlatFilePos in UndoReadFromDisk (MarcoFalke)
aaaa3323f37526862ebf2a2a4bf522c661e6976e refactor: Mark IsBlockPruned const (MarcoFalke)

Pull request description:

  These errors should never happen in normal operation. If they do,
  knowing the `FlatFilePos` may be useful to determine if data corruption
  happened. Also, handle the error `pos.IsNull()` as part of `OpenUndoFile`,
  because it may as well have happened due to data corruption.

  This mirrors the `LogError` behavior from `ReadBlockFromDisk`.

  Also, two other fixup commits in this module.

ACKs for top commit:
  kevkevinpal:
    ACK [fa14e1d](https://github.com/bitcoin/bitcoin/pull/30428/commits/fa14e1d9d5c5dc44396a01583ae94480b7bc29ee)
  tdb3:
    cr and light test ACK fa14e1d9d5c5dc44396a01583ae94480b7bc29ee
  ryanofsky:
    Code review ACK fa14e1d9d5c5dc44396a01583ae94480b7bc29ee. This should make logging clearer and more consistent

Tree-SHA512: abb492a919b4796698d1de0a7874c8eae355422b992aa80dcd6b59c2de1ee0d2949f62b3cf649cd62892976fee640358f7522867ed9d48a595d6f8f4e619df50

2 files changed, 12 insertions, 18 deletions

diff --git a/src/node/blockstorage.cpp b/src/node/blockstorage.cpp
index 80aceb312a..c50625f58d 100644
--- a/src/node/blockstorage.cpp
+++ b/src/node/blockstorage.cpp
@@ -588,7 +588,7 @@ const CBlockIndex* BlockManager::GetLastCheckpoint(const CCheckpointData& data)
     return nullptr;
 }
 
-bool BlockManager::IsBlockPruned(const CBlockIndex& block)
+bool BlockManager::IsBlockPruned(const CBlockIndex& block) const
 {
     AssertLockHeld(::cs_main);
     return m_have_pruned && !(block.nStatus & BLOCK_HAVE_DATA) && (block.nTx > 0);
@@ -703,15 +703,10 @@ bool BlockManager::UndoReadFromDisk(CBlockUndo& blockundo, const CBlockIndex& in
 {
     const FlatFilePos pos{WITH_LOCK(::cs_main, return index.GetUndoPos())};
 
-    if (pos.IsNull()) {
-        LogError("%s: no undo data available\n", __func__);
-        return false;
-    }
-
     // Open history file to read
     AutoFile filein{OpenUndoFile(pos, true)};
     if (filein.IsNull()) {
-        LogError("%s: OpenUndoFile failed\n", __func__);
+        LogError("%s: OpenUndoFile failed for %s\n", __func__, pos.ToString());
         return false;
     }
 
@@ -723,13 +718,13 @@ bool BlockManager::UndoReadFromDisk(CBlockUndo& blockundo, const CBlockIndex& in
         verifier >> blockundo;
         filein >> hashChecksum;
     } catch (const std::exception& e) {
-        LogError("%s: Deserialize or I/O error - %s\n", __func__, e.what());
+        LogError("%s: Deserialize or I/O error - %s at %s\n", __func__, e.what(), pos.ToString());
         return false;
     }
 
     // Verify checksum
     if (hashChecksum != verifier.GetHash()) {
-        LogError("%s: Checksum mismatch\n", __func__);
+        LogError("%s: Checksum mismatch at %s\n", __func__, pos.ToString());
         return false;
     }
 
@@ -986,7 +981,7 @@ bool BlockManager::WriteBlockToDisk(const CBlock& block, FlatFilePos& pos) const
     // Open history file to append
     AutoFile fileout{OpenBlockFile(pos)};
     if (fileout.IsNull()) {
-        LogError("WriteBlockToDisk: OpenBlockFile failed\n");
+        LogError("%s: OpenBlockFile failed\n", __func__);
         return false;
     }
 
@@ -997,7 +992,7 @@ bool BlockManager::WriteBlockToDisk(const CBlock& block, FlatFilePos& pos) const
     // Write block
     long fileOutPos = ftell(fileout.Get());
     if (fileOutPos < 0) {
-        LogError("WriteBlockToDisk: ftell failed\n");
+        LogError("%s: ftell failed\n", __func__);
         return false;
     }
     pos.nPos = (unsigned int)fileOutPos;
@@ -1016,7 +1011,7 @@ bool BlockManager::WriteUndoDataForBlock(const CBlockUndo& blockundo, BlockValid
     if (block.GetUndoPos().IsNull()) {
         FlatFilePos _pos;
         if (!FindUndoPos(state, block.nFile, _pos, ::GetSerializeSize(blockundo) + 40)) {
-            LogError("ConnectBlock(): FindUndoPos failed\n");
+            LogError("%s: FindUndoPos failed\n", __func__);
             return false;
         }
         if (!UndoWriteToDisk(blockundo, _pos, block.pprev->GetBlockHash())) {
@@ -1055,7 +1050,7 @@ bool BlockManager::ReadBlockFromDisk(CBlock& block, const FlatFilePos& pos) cons
     // Open history file to read
     AutoFile filein{OpenBlockFile(pos, true)};
     if (filein.IsNull()) {
-        LogError("ReadBlockFromDisk: OpenBlockFile failed for %s\n", pos.ToString());
+        LogError("%s: OpenBlockFile failed for %s\n", __func__, pos.ToString());
         return false;
     }
 
@@ -1069,13 +1064,13 @@ bool BlockManager::ReadBlockFromDisk(CBlock& block, const FlatFilePos& pos) cons
 
     // Check the header
     if (!CheckProofOfWork(block.GetHash(), block.nBits, GetConsensus())) {
-        LogError("ReadBlockFromDisk: Errors in block header at %s\n", pos.ToString());
+        LogError("%s: Errors in block header at %s\n", __func__, pos.ToString());
         return false;
     }
 
     // Signet only: check block solution
     if (GetConsensus().signet_blocks && !CheckSignetBlockSolution(block, GetConsensus())) {
-        LogError("ReadBlockFromDisk: Errors in block solution at %s\n", pos.ToString());
+        LogError("%s: Errors in block solution at %s\n", __func__, pos.ToString());
         return false;
     }
 
@@ -1090,8 +1085,7 @@ bool BlockManager::ReadBlockFromDisk(CBlock& block, const CBlockIndex& index) co
         return false;
     }
     if (block.GetHash() != index.GetBlockHash()) {
-        LogError("ReadBlockFromDisk(CBlock&, CBlockIndex*): GetHash() doesn't match index for %s at %s\n",
-                     index.ToString(), block_pos.ToString());
+        LogError("%s: GetHash() doesn't match index for %s at %s\n", __func__, index.ToString(), block_pos.ToString());
         return false;
     }
     return true;
diff --git a/src/node/blockstorage.h b/src/node/blockstorage.h
index 0a46d79764..a946b4ea94 100644
--- a/src/node/blockstorage.h
+++ b/src/node/blockstorage.h
@@ -404,7 +404,7 @@ public:
     bool m_have_pruned = false;
 
     //! Check whether the block associated with this index entry is pruned or not.
-    bool IsBlockPruned(const CBlockIndex& block) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
+    bool IsBlockPruned(const CBlockIndex& block) const EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     //! Create or update a prune lock identified by its name
     void UpdatePruneLock(const std::string& name, const PruneLockInfo& lock_info) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);