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author | Dhruv Mehta <856960+dhruv@users.noreply.github.com> | 2021-01-24 15:14:15 -0800 |
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committer | Dhruv Mehta <856960+dhruv@users.noreply.github.com> | 2021-04-21 16:09:14 -0700 |
commit | d831e711cab83c70bf2ded62fe33f484844e73dd (patch) | |
tree | 10c6e33cf3a3814dd73ec186d442d217800cb149 /src | |
parent | 92cf3a22e3c79ce28c5cc9dcbc18348c43cbe4d9 (diff) | |
download | bitcoin-d831e711cab83c70bf2ded62fe33f484844e73dd.tar.xz |
[validation] RewindBlockIndex no longer needed
Instead of rewinding blocks, we request that the user restarts with
-reindex
Diffstat (limited to 'src')
-rw-r--r-- | src/init.cpp | 28 | ||||
-rw-r--r-- | src/validation.cpp | 140 | ||||
-rw-r--r-- | src/validation.h | 7 |
3 files changed, 21 insertions, 154 deletions
diff --git a/src/init.cpp b/src/init.cpp index 584b148aff..a1c026f806 100644 --- a/src/init.cpp +++ b/src/init.cpp @@ -1698,29 +1698,17 @@ bool AppInitMain(const util::Ref& context, NodeContext& node, interfaces::BlockA break; } - bool failed_rewind{false}; - // Can't hold cs_main while calling RewindBlockIndex, so retrieve the relevant - // chainstates beforehand. - for (CChainState* chainstate : WITH_LOCK(::cs_main, return chainman.GetAll())) { - if (!fReset) { - // Note that RewindBlockIndex MUST run even if we're about to -reindex-chainstate. - // It both disconnects blocks based on the chainstate, and drops block data in - // BlockIndex() based on lack of available witness data. - uiInterface.InitMessage(_("Rewinding blocks...").translated); - if (!chainstate->RewindBlockIndex(chainparams)) { - strLoadError = _( - "Unable to rewind the database to a pre-fork state. " - "You will need to redownload the blockchain"); - failed_rewind = true; - break; // out of the per-chainstate loop - } + if (!fReset) { + LOCK(cs_main); + auto chainstates{chainman.GetAll()}; + if (std::any_of(chainstates.begin(), chainstates.end(), + [&chainparams](const CChainState* cs) EXCLUSIVE_LOCKS_REQUIRED(cs_main) { return cs->NeedsRedownload(chainparams); })) { + strLoadError = strprintf(_("Witness data for blocks after height %d requires validation. Please restart with -reindex."), + chainparams.GetConsensus().SegwitHeight); + break; } } - if (failed_rewind) { - break; // out of the chainstate activation do-while - } - bool failed_verification = false; try { diff --git a/src/validation.cpp b/src/validation.cpp index 0c3aeced93..fdc7ef8845 100644 --- a/src/validation.cpp +++ b/src/validation.cpp @@ -4431,143 +4431,23 @@ bool CChainState::ReplayBlocks(const CChainParams& params) return true; } -//! Helper for CChainState::RewindBlockIndex -void CChainState::EraseBlockData(CBlockIndex* index) +bool CChainState::NeedsRedownload(const CChainParams& params) const { AssertLockHeld(cs_main); - assert(!m_chain.Contains(index)); // Make sure this block isn't active - - // Reduce validity - index->nStatus = std::min<unsigned int>(index->nStatus & BLOCK_VALID_MASK, BLOCK_VALID_TREE) | (index->nStatus & ~BLOCK_VALID_MASK); - // Remove have-data flags. - index->nStatus &= ~(BLOCK_HAVE_DATA | BLOCK_HAVE_UNDO); - // Remove storage location. - index->nFile = 0; - index->nDataPos = 0; - index->nUndoPos = 0; - // Remove various other things - index->nTx = 0; - index->nChainTx = 0; - index->nSequenceId = 0; - // Make sure it gets written. - setDirtyBlockIndex.insert(index); - // Update indexes - setBlockIndexCandidates.erase(index); - auto ret = m_blockman.m_blocks_unlinked.equal_range(index->pprev); - while (ret.first != ret.second) { - if (ret.first->second == index) { - m_blockman.m_blocks_unlinked.erase(ret.first++); - } else { - ++ret.first; - } - } - // Mark parent as eligible for main chain again - if (index->pprev && index->pprev->IsValid(BLOCK_VALID_TRANSACTIONS) && index->pprev->HaveTxsDownloaded()) { - setBlockIndexCandidates.insert(index->pprev); - } -} - -bool CChainState::RewindBlockIndex(const CChainParams& params) -{ - // Note that during -reindex-chainstate we are called with an empty m_chain! - // First erase all post-segwit blocks without witness not in the main chain, - // as this can we done without costly DisconnectTip calls. Active - // blocks will be dealt with below (releasing cs_main in between). - { - LOCK(cs_main); - for (const auto& entry : m_blockman.m_block_index) { - if (IsWitnessEnabled(entry.second->pprev, params.GetConsensus()) && !(entry.second->nStatus & BLOCK_OPT_WITNESS) && !m_chain.Contains(entry.second)) { - EraseBlockData(entry.second); - } - } - } + // At and above params.SegwitHeight, segwit consensus rules must be validated + CBlockIndex* block{m_chain.Tip()}; + const int segwit_height{params.GetConsensus().SegwitHeight}; - // Find what height we need to reorganize to. - CBlockIndex *tip; - int nHeight = 1; - { - LOCK(cs_main); - while (nHeight <= m_chain.Height()) { - // Although SCRIPT_VERIFY_WITNESS is now generally enforced on all - // blocks in ConnectBlock, we don't need to go back and - // re-download/re-verify blocks from before segwit actually activated. - if (IsWitnessEnabled(m_chain[nHeight - 1], params.GetConsensus()) && !(m_chain[nHeight]->nStatus & BLOCK_OPT_WITNESS)) { - break; - } - nHeight++; - } - - tip = m_chain.Tip(); - } - // nHeight is now the height of the first insufficiently-validated block, or tipheight + 1 - - BlockValidationState state; - // Loop until the tip is below nHeight, or we reach a pruned block. - while (!ShutdownRequested()) { - { - LOCK(cs_main); - LOCK(m_mempool.cs); - // Make sure nothing changed from under us (this won't happen because RewindBlockIndex runs before importing/network are active) - assert(tip == m_chain.Tip()); - if (tip == nullptr || tip->nHeight < nHeight) break; - if (fPruneMode && !(tip->nStatus & BLOCK_HAVE_DATA)) { - // If pruning, don't try rewinding past the HAVE_DATA point; - // since older blocks can't be served anyway, there's - // no need to walk further, and trying to DisconnectTip() - // will fail (and require a needless reindex/redownload - // of the blockchain). - break; - } - - // Disconnect block - if (!DisconnectTip(state, params, nullptr)) { - return error("RewindBlockIndex: unable to disconnect block at height %i (%s)", tip->nHeight, state.ToString()); - } - - // Reduce validity flag and have-data flags. - // We do this after actual disconnecting, otherwise we'll end up writing the lack of data - // to disk before writing the chainstate, resulting in a failure to continue if interrupted. - // Note: If we encounter an insufficiently validated block that - // is on m_chain, it must be because we are a pruning node, and - // this block or some successor doesn't HAVE_DATA, so we were unable to - // rewind all the way. Blocks remaining on m_chain at this point - // must not have their validity reduced. - EraseBlockData(tip); - - tip = tip->pprev; - } - // Make sure the queue of validation callbacks doesn't grow unboundedly. - LimitValidationInterfaceQueue(); - - // Occasionally flush state to disk. - if (!FlushStateToDisk(params, state, FlushStateMode::PERIODIC)) { - LogPrintf("RewindBlockIndex: unable to flush state to disk (%s)\n", state.ToString()); - return false; - } - } - - { - LOCK(cs_main); - if (m_chain.Tip() != nullptr) { - // We can't prune block index candidates based on our tip if we have - // no tip due to m_chain being empty! - PruneBlockIndexCandidates(); - - CheckBlockIndex(params.GetConsensus()); - - // FlushStateToDisk can possibly read ::ChainActive(). Be conservative - // and skip it here, we're about to -reindex-chainstate anyway, so - // it'll get called a bunch real soon. - BlockValidationState state; - if (!FlushStateToDisk(params, state, FlushStateMode::ALWAYS)) { - LogPrintf("RewindBlockIndex: unable to flush state to disk (%s)\n", state.ToString()); - return false; - } + while (block != nullptr && block->nHeight >= segwit_height) { + if (!(block->nStatus & BLOCK_OPT_WITNESS)) { + // block is insufficiently validated for a segwit client + return true; } + block = block->pprev; } - return true; + return false; } void CChainState::UnloadBlockIndex() { diff --git a/src/validation.h b/src/validation.h index 512b306219..3c7f593c82 100644 --- a/src/validation.h +++ b/src/validation.h @@ -722,7 +722,9 @@ public: /** Replay blocks that aren't fully applied to the database. */ bool ReplayBlocks(const CChainParams& params); - bool RewindBlockIndex(const CChainParams& params) LOCKS_EXCLUDED(cs_main); + + /** Whether the chain state needs to be redownloaded due to lack of witness data */ + [[nodiscard]] bool NeedsRedownload(const CChainParams& params) const EXCLUSIVE_LOCKS_REQUIRED(cs_main); /** Ensures we have a genesis block in the block tree, possibly writing one to disk. */ bool LoadGenesisBlock(const CChainParams& chainparams); @@ -769,9 +771,6 @@ private: bool RollforwardBlock(const CBlockIndex* pindex, CCoinsViewCache& inputs, const CChainParams& params) EXCLUSIVE_LOCKS_REQUIRED(cs_main); - //! Mark a block as not having block data - void EraseBlockData(CBlockIndex* index) EXCLUSIVE_LOCKS_REQUIRED(cs_main); - void CheckForkWarningConditions() EXCLUSIVE_LOCKS_REQUIRED(cs_main); void InvalidChainFound(CBlockIndex* pindexNew) EXCLUSIVE_LOCKS_REQUIRED(cs_main); |