Handle ReadBlockFromDisk failure during IBD gracefully

During Initial Block Download, block data may not be flushed to disk
when the wallet notification thread tries to read it. Instead of
crashing with a fatal error, log a message and retry on the next cycle.

build.sh

@@ -6,7 +6,7 @@
 
 set -eu -o pipefail
 
-VERSION="1.0.0"
+VERSION="1.0.1"
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 RELEASE_DIR="$SCRIPT_DIR/release"
 

configure.ac

@@ -3,7 +3,7 @@ AC_PREREQ([2.60])
 define(_CLIENT_VERSION_MAJOR, 1)
 dnl Must be kept in sync with src/clientversion.h , ugh!
 define(_CLIENT_VERSION_MINOR, 0)
-define(_CLIENT_VERSION_REVISION, 0)
+define(_CLIENT_VERSION_REVISION, 1)
 define(_CLIENT_VERSION_BUILD, 50)
 define(_ZC_BUILD_VAL, m4_if(m4_eval(_CLIENT_VERSION_BUILD < 25), 1, m4_incr(_CLIENT_VERSION_BUILD), m4_eval(_CLIENT_VERSION_BUILD < 50), 1, m4_eval(_CLIENT_VERSION_BUILD - 24), m4_eval(_CLIENT_VERSION_BUILD == 50), 1, , m4_eval(_CLIENT_VERSION_BUILD - 50)))
 define(_CLIENT_VERSION_SUFFIX, m4_if(m4_eval(_CLIENT_VERSION_BUILD < 25), 1, _CLIENT_VERSION_REVISION-beta$1, m4_eval(_CLIENT_VERSION_BUILD < 50), 1, _CLIENT_VERSION_REVISION-rc$1, m4_eval(_CLIENT_VERSION_BUILD == 50), 1, _CLIENT_VERSION_REVISION, _CLIENT_VERSION_REVISION-$1)))

src/clientversion.h

@@ -30,7 +30,7 @@
 // Must be kept in sync with configure.ac , ugh!
 #define CLIENT_VERSION_MAJOR 1
 #define CLIENT_VERSION_MINOR 0
-#define CLIENT_VERSION_REVISION 0
+#define CLIENT_VERSION_REVISION 1
 #define CLIENT_VERSION_BUILD 50
 
 //! Set to true for release, false for prerelease or test build

src/main.cpp

@@ -5107,7 +5107,14 @@ bool ContextualCheckBlockHeader(const CBlockHeader& block, CValidationState& sta
 
     assert(pindexPrev);
 
-    int daaForkHeight = GetArg("-daaforkheight", 450000);
+    // For HUSH3, nBits validation starts above the original DAA fork height (450000).
+    // For DragonX, nBits was never validated before the standalone binary, so the
+    // chain contains blocks with incorrect nBits during the vulnerable window
+    // (diff reset at RANDOMX_VALIDATION height through the attack at ~2879907).
+    // Set daaForkHeight past that window so fresh sync accepts historical blocks.
+    bool isdragonx    = strncmp(SMART_CHAIN_SYMBOL, "DRAGONX", 7) == 0;
+    int defaultDaaForkHeight = isdragonx ? ASSETCHAINS_RANDOMX_VALIDATION + 62000 : 450000;
+    int daaForkHeight = GetArg("-daaforkheight", defaultDaaForkHeight);
     int nHeight       = pindexPrev->GetHeight()+1;
     bool ishush3      = strncmp(SMART_CHAIN_SYMBOL, "HUSH3",5) == 0 ? true : false;
     // Check Proof-of-Work difficulty

src/pow.cpp

@@ -315,6 +315,16 @@ unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHead
     if (pindexLast == NULL )
         return nProofOfWorkLimit;
 
+    // DragonX difficulty reset at the RANDOMX_VALIDATION activation height.
+    // The chain transitioned to a new binary at this height and difficulty was
+    // reset to minimum (powLimit).  Without this, fresh-syncing nodes compute
+    // a different nBits from GetNextWorkRequired (based on pre-reset blocks)
+    // and reject the on-chain min-diff block, banning all seed nodes.
+    if (ASSETCHAINS_RANDOMX_VALIDATION > 0 && pindexLast->GetHeight() + 1 == ASSETCHAINS_RANDOMX_VALIDATION) {
+        LogPrintf("%s: difficulty reset to powLimit at height %d\n", __func__, ASSETCHAINS_RANDOMX_VALIDATION);
+        return nProofOfWorkLimit;
+    }
+
     //{
         // Comparing to pindexLast->nHeight with >= because this function
         // returns the work required for the block after pindexLast.

src/validationinterface.cpp

@@ -179,6 +179,13 @@ void ThreadNotifyWallets(CBlockIndex *pindexLastTip)
             // Read block from disk.
             CBlock block;
             if (!ReadBlockFromDisk(block, pindexLastTip,1)) {
+                if (IsInitialBlockDownload()) {
+                    // During IBD, block data may not be flushed to disk yet.
+                    // Sleep briefly and retry on the next cycle instead of crashing.
+                    LogPrintf("%s: block at height %d not yet readable, will retry\n",
+                              __func__, pindexLastTip->GetHeight());
+                    break;
+                }
                 LogPrintf("*** %s\n", "Failed to read block while notifying wallets of block disconnects");
                 uiInterface.ThreadSafeMessageBox(
                     _("Error: A fatal internal error occurred, see debug.log for details"),
@@ -206,6 +213,14 @@ void ThreadNotifyWallets(CBlockIndex *pindexLastTip)
             // Read block from disk.
             CBlock block;
             if (!ReadBlockFromDisk(block, blockData.pindex, 1)) {
+                if (IsInitialBlockDownload()) {
+                    // During IBD, block data may not be flushed to disk yet.
+                    // Push unprocessed blocks back and retry on the next cycle.
+                    LogPrintf("%s: block at height %d not yet readable, will retry\n",
+                              __func__, blockData.pindex->GetHeight());
+                    blockStack.push_back(blockData);
+                    break;
+                }
                 LogPrintf("*** %s\n", "Failed to read block while notifying wallets of block connects");
                 uiInterface.ThreadSafeMessageBox(
                     _("Error: A fatal internal error occurred, see debug.log for details"),