Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Browse files

New database check routine

-checklevel gets a new meaning:
0: verify blocks can be read from disk (like before)
1: verify (contextless) block validity (like before)
2: verify undo files can be read and have good checksums
3: verify coin database is consistent with the last few blocks
   (close to level 6 before)
4: verify all validity rules of the last few blocks

Level 3 is the new default, as it's reasonably fast. As level 3 and
4 are implemented using an in-memory rollback of the database, they
are limited to as many blocks as possible without exceeding the
limits set by -dbcache. The default of -dbcache=25 allows for some
150-200 blocks to be rolled back.

In case an error is found, the application quits with a message
instructing the user to restart with -reindex. Better instructions,
and automatic recovery (when possible) or automatic reindexing are
left as future work.
  • Loading branch information...
commit 1f355b66cd90f1bd96a862604a7216e8ba56f853 1 parent 8539361
@sipa authored
Showing with 60 additions and 14 deletions.
  1. +5 −2 src/init.cpp
  2. +53 −12 src/main.cpp
  3. +2 −0  src/main.h
View
7 src/init.cpp
@@ -300,7 +300,7 @@ std::string HelpMessage()
" -rescan " + _("Rescan the block chain for missing wallet transactions") + "\n" +
" -salvagewallet " + _("Attempt to recover private keys from a corrupt wallet.dat") + "\n" +
" -checkblocks=<n> " + _("How many blocks to check at startup (default: 2500, 0 = all)") + "\n" +
- " -checklevel=<n> " + _("How thorough the block verification is (0-6, default: 1)") + "\n" +
+ " -checklevel=<n> " + _("How thorough the block verification is (0-4, default: 3)") + "\n" +
" -loadblock=<file> " + _("Imports blocks from external blk000??.dat file") + "\n" +
" -reindex " + _("Rebuild blockchain index from current blk000??.dat files") + "\n" +
@@ -752,7 +752,10 @@ bool AppInit2()
pblocktree->WriteReindexing(true);
if (!LoadBlockIndex())
- return InitError(_("Error loading blkindex.dat"));
+ return InitError(_("Error loading block/coin databases"));
+
+ if (!VerifyDB())
+ return InitError(_("Corrupted database detected. Please restart the client with -reindex."));
// as LoadBlockIndex can take several minutes, it's possible the user
// requested to kill bitcoin-qt during the last operation. If so, exit.
View
65 src/main.cpp
@@ -2388,36 +2388,77 @@ bool static LoadBlockIndexDB()
BlockHashStr(hashBestChain).c_str(), nBestHeight,
DateTimeStrFormat("%Y-%m-%d %H:%M:%S", pindexBest->GetBlockTime()).c_str());
+ return true;
+}
+
+bool VerifyDB() {
+ if (pindexBest == NULL || pindexBest->pprev == NULL)
+ return true;
+
// Verify blocks in the best chain
- int nCheckLevel = GetArg("-checklevel", 1);
+ int nCheckLevel = GetArg("-checklevel", 3);
int nCheckDepth = GetArg( "-checkblocks", 2500);
if (nCheckDepth == 0)
nCheckDepth = 1000000000; // suffices until the year 19000
if (nCheckDepth > nBestHeight)
nCheckDepth = nBestHeight;
+ nCheckLevel = std::max(0, std::min(4, nCheckLevel));
printf("Verifying last %i blocks at level %i\n", nCheckDepth, nCheckLevel);
- CBlockIndex* pindexFork = NULL;
+ CCoinsViewCache coins(*pcoinsTip, true);
+ CBlockIndex* pindexState = pindexBest;
+ CBlockIndex* pindexFailure = NULL;
+ int nGoodTransactions = 0;
for (CBlockIndex* pindex = pindexBest; pindex && pindex->pprev; pindex = pindex->pprev)
{
if (fRequestShutdown || pindex->nHeight < nBestHeight-nCheckDepth)
break;
CBlock block;
+ // check level 0: read from disk
if (!block.ReadFromDisk(pindex))
- return error("LoadBlockIndex() : block.ReadFromDisk failed");
+ return error("VerifyDB() : *** block.ReadFromDisk failed at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString().c_str());
// check level 1: verify block validity
- if (nCheckLevel>0 && !block.CheckBlock())
- {
- printf("LoadBlockIndex() : *** found bad block at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString().c_str());
- pindexFork = pindex->pprev;
+ if (nCheckLevel >= 1 && !block.CheckBlock())
+ return error("VerifyDB() : *** found bad block at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString().c_str());
+ // check level 2: verify undo validity
+ if (nCheckLevel >= 2 && pindex) {
+ CBlockUndo undo;
+ CDiskBlockPos pos = pindex->GetUndoPos();
+ if (!pos.IsNull()) {
+ if (!undo.ReadFromDisk(pos, pindex->pprev->GetBlockHash()))
+ return error("VerifyDB() : *** found bad undo data at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString().c_str());
+ }
+ }
+ // check level 3: check for inconsistencies during memory-only disconnect of tip blocks
+ if (nCheckLevel >= 3 && pindex == pindexState && (coins.GetCacheSize() + pcoinsTip->GetCacheSize()) <= 2*nCoinCacheSize + 32000) {
+ bool fClean = true;
+ if (!block.DisconnectBlock(pindex, coins, &fClean))
+ return error("VerifyDB() : *** irrecoverable inconsistency in block data at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString().c_str());
+ pindexState = pindex->pprev;
+ if (!fClean) {
+ nGoodTransactions = 0;
+ pindexFailure = pindex;
+ } else
+ nGoodTransactions += block.vtx.size();
}
- // TODO: stronger verifications
}
- if (pindexFork && !fRequestShutdown)
- {
- // TODO: reorg back
- return error("LoadBlockIndex(): chain database corrupted");
+ if (pindexFailure)
+ return error("VerifyDB() : *** coin database inconsistencies found (last %i blocks, %i good transactions before that)\n", pindexBest->nHeight - pindexFailure->nHeight + 1, nGoodTransactions);
+
+ // check level 4: try reconnecting blocks
+ if (nCheckLevel >= 4) {
+ CBlockIndex *pindex = pindexState;
+ while (pindex != pindexBest && !fRequestShutdown) {
+ pindex = pindex->pnext;
+ CBlock block;
+ if (!block.ReadFromDisk(pindex))
+ return error("VerifyDB() : *** block.ReadFromDisk failed at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString().c_str());
+ if (!block.ConnectBlock(pindex, coins))
+ return error("VerifyDB() : *** found unconnectable block at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString().c_str());
+ }
}
+ printf("No coin database inconsistencies in last %i blocks (%i transactions)\n", pindexBest->nHeight - pindexState->nHeight, nGoodTransactions);
+
return true;
}
View
2  src/main.h
@@ -126,6 +126,8 @@ FILE* OpenUndoFile(const CDiskBlockPos &pos, bool fReadOnly = false);
bool LoadExternalBlockFile(FILE* fileIn, CDiskBlockPos *dbp = NULL);
/** Load the block tree and coins database from disk */
bool LoadBlockIndex();
+/** Verify consistency of the block and coin databases */
+bool VerifyDB();
/** Print the loaded block tree */
void PrintBlockTree();
/** Find a block by height in the currently-connected chain */
Please sign in to comment.
Something went wrong with that request. Please try again.