diff options
| -rw-r--r-- | src/validation.cpp | 46 | ||||
| -rwxr-xr-x | test/functional/feature_reindex.py | 50 |
2 files changed, 78 insertions, 18 deletions
diff --git a/src/validation.cpp b/src/validation.cpp index 37e68cfe4a..b9105b9090 100644 --- a/src/validation.cpp +++ b/src/validation.cpp @@ -4393,6 +4393,8 @@ void Chainstate::LoadExternalBlockFile( try { // This takes over fileIn and calls fclose() on it in the CBufferedFile destructor CBufferedFile blkdat(fileIn, 2*MAX_BLOCK_SERIALIZED_SIZE, MAX_BLOCK_SERIALIZED_SIZE+8, SER_DISK, CLIENT_VERSION); + // nRewind indicates where to resume scanning in case something goes wrong, + // such as a block fails to deserialize. uint64_t nRewind = blkdat.GetPos(); while (!blkdat.eof()) { if (ShutdownRequested()) return; @@ -4416,28 +4418,30 @@ void Chainstate::LoadExternalBlockFile( continue; } catch (const std::exception&) { // no valid block header found; don't complain + // (this happens at the end of every blk.dat file) break; } try { - // read block - uint64_t nBlockPos = blkdat.GetPos(); + // read block header + const uint64_t nBlockPos{blkdat.GetPos()}; if (dbp) dbp->nPos = nBlockPos; blkdat.SetLimit(nBlockPos + nSize); - std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>(); - CBlock& block = *pblock; - blkdat >> block; - nRewind = blkdat.GetPos(); - - uint256 hash = block.GetHash(); + CBlockHeader header; + blkdat >> header; + const uint256 hash{header.GetHash()}; + // Skip the rest of this block (this may read from disk into memory); position to the marker before the + // next block, but it's still possible to rewind to the start of the current block (without a disk read). + nRewind = nBlockPos + nSize; + blkdat.SkipTo(nRewind); { LOCK(cs_main); // detect out of order blocks, and store them for later - if (hash != params.GetConsensus().hashGenesisBlock && !m_blockman.LookupBlockIndex(block.hashPrevBlock)) { + if (hash != params.GetConsensus().hashGenesisBlock && !m_blockman.LookupBlockIndex(header.hashPrevBlock)) { LogPrint(BCLog::REINDEX, "%s: Out of order block %s, parent %s not known\n", __func__, hash.ToString(), - block.hashPrevBlock.ToString()); + header.hashPrevBlock.ToString()); if (dbp && blocks_with_unknown_parent) { - blocks_with_unknown_parent->emplace(block.hashPrevBlock, *dbp); + blocks_with_unknown_parent->emplace(header.hashPrevBlock, *dbp); } continue; } @@ -4445,13 +4449,19 @@ void Chainstate::LoadExternalBlockFile( // process in case the block isn't known yet const CBlockIndex* pindex = m_blockman.LookupBlockIndex(hash); if (!pindex || (pindex->nStatus & BLOCK_HAVE_DATA) == 0) { - BlockValidationState state; - if (AcceptBlock(pblock, state, nullptr, true, dbp, nullptr, true)) { - nLoaded++; - } - if (state.IsError()) { - break; - } + // This block can be processed immediately; rewind to its start, read and deserialize it. + blkdat.SetPos(nBlockPos); + std::shared_ptr<CBlock> pblock{std::make_shared<CBlock>()}; + blkdat >> *pblock; + nRewind = blkdat.GetPos(); + + BlockValidationState state; + if (AcceptBlock(pblock, state, nullptr, true, dbp, nullptr, true)) { + nLoaded++; + } + if (state.IsError()) { + break; + } } else if (hash != params.GetConsensus().hashGenesisBlock && pindex->nHeight % 1000 == 0) { LogPrint(BCLog::REINDEX, "Block Import: already had block %s at height %d\n", hash.ToString(), pindex->nHeight); } diff --git a/test/functional/feature_reindex.py b/test/functional/feature_reindex.py index 44040f426f..0f6a8fd0d2 100755 --- a/test/functional/feature_reindex.py +++ b/test/functional/feature_reindex.py @@ -7,9 +7,12 @@ - Start a single node and generate 3 blocks. - Stop the node and restart it with -reindex. Verify that the node has reindexed up to block 3. - Stop the node and restart it with -reindex-chainstate. Verify that the node has reindexed up to block 3. +- Verify that out-of-order blocks are correctly processed, see LoadExternalBlockFile() """ +import os from test_framework.test_framework import BitcoinTestFramework +from test_framework.p2p import MAGIC_BYTES from test_framework.util import assert_equal @@ -27,11 +30,58 @@ class ReindexTest(BitcoinTestFramework): assert_equal(self.nodes[0].getblockcount(), blockcount) # start_node is blocking on reindex self.log.info("Success") + # Check that blocks can be processed out of order + def out_of_order(self): + # The previous test created 12 blocks + assert_equal(self.nodes[0].getblockcount(), 12) + self.stop_nodes() + + # In this test environment, blocks will always be in order (since + # we're generating them rather than getting them from peers), so to + # test out-of-order handling, swap blocks 1 and 2 on disk. + blk0 = os.path.join(self.nodes[0].datadir, self.nodes[0].chain, 'blocks', 'blk00000.dat') + with open(blk0, 'r+b') as bf: + # Read at least the first few blocks (including genesis) + b = bf.read(2000) + + # Find the offsets of blocks 2, 3, and 4 (the first 3 blocks beyond genesis) + # by searching for the regtest marker bytes (see pchMessageStart). + def find_block(b, start): + return b.find(MAGIC_BYTES["regtest"], start)+4 + + genesis_start = find_block(b, 0) + assert_equal(genesis_start, 4) + b2_start = find_block(b, genesis_start) + b3_start = find_block(b, b2_start) + b4_start = find_block(b, b3_start) + + # Blocks 2 and 3 should be the same size. + assert_equal(b3_start-b2_start, b4_start-b3_start) + + # Swap the second and third blocks (don't disturb the genesis block). + bf.seek(b2_start) + bf.write(b[b3_start:b4_start]) + bf.write(b[b2_start:b3_start]) + + # The reindexing code should detect and accommodate out of order blocks. + with self.nodes[0].assert_debug_log([ + 'LoadExternalBlockFile: Out of order block', + 'LoadExternalBlockFile: Processing out of order child', + ]): + extra_args = [["-reindex"]] + self.start_nodes(extra_args) + + # All blocks should be accepted and processed. + assert_equal(self.nodes[0].getblockcount(), 12) + def run_test(self): self.reindex(False) self.reindex(True) self.reindex(False) self.reindex(True) + self.out_of_order() + + if __name__ == '__main__': ReindexTest().main() |