Merge bitcoin/bitcoin#24236: Remove utxo db upgrade code

fa9112aac0 Remove utxo db upgrade code (MarcoFalke)

Pull request description:

  It is not possible to upgrade Bitcoin Core pre-segwit (pre-0.13.1) to a recent version without a full IBD from scratch after  commit 19a56d1519 (released in version 22.0).

  Any Bitcoin Core version with the new database format after commit 1088b02f0c (released in version 0.15), can upgrade to any version that is supported as of today.

  This leaves the versions 0.13.1-0.14.x. Even though those versions are unsupported, some users with an existing datadir may want to upgrade to a recent version. However, it seems reasonable to simply ask them to `-reindex` to run a full IBD from scratch. This allows us to remove the utxo db upgrade code.

ACKs for top commit:
  Sjors:
    re-ACK fa9112aac0
  laanwj:
    Code review ACK fa9112aac0

Tree-SHA512: 4243bb35df9ac4892f9fad30fe486d338745952bcff4160bcb0937c772d57b13b800647da14695e21e3655e85ee0d95fa3dc7789ee309d59ad84f422297fecb8

ci/test/00_setup_env_native_qt5.sh

@@ -14,6 +14,6 @@ export TEST_RUNNER_EXTRA="--previous-releases --coverage --extended --exclude fe
 export RUN_UNIT_TESTS_SEQUENTIAL="true"
 export RUN_UNIT_TESTS="false"
 export GOAL="install"
-export PREVIOUS_RELEASES_TO_DOWNLOAD="v0.15.2 v0.16.3 v0.17.2 v0.18.1 v0.19.1 v0.20.1 v0.21.0 v22.0"
+export PREVIOUS_RELEASES_TO_DOWNLOAD="v0.14.3 v0.15.2 v0.16.3 v0.17.2 v0.18.1 v0.19.1 v0.20.1 v0.21.0 v22.0"
 export BITCOIN_CONFIG="--enable-zmq --with-libs=no --with-gui=qt5 --enable-reduce-exports \
 --enable-debug CFLAGS=\"-g0 -O2 -funsigned-char\" CXXFLAGS=\"-g0 -O2 -funsigned-char\" CC=gcc-8 CXX=g++-8"

src/init.cpp

@@ -1453,8 +1453,9 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
                 strLoadError = _("Error initializing block database");
                 break;
             case ChainstateLoadingError::ERROR_CHAINSTATE_UPGRADE_FAILED:
-                strLoadError = _("Error upgrading chainstate database");
-                break;
+                return InitError(_("Unsupported chainstate database format found. "
+                                   "Please restart with -reindex-chainstate. This will "
+                                   "rebuild the chainstate database."));
             case ChainstateLoadingError::ERROR_REPLAYBLOCKS_FAILED:
                 strLoadError = _("Unable to replay blocks. You will need to rebuild the database using -reindex-chainstate.");
                 break;

src/node/chainstate.cpp

@@ -90,9 +90,9 @@ std::optional<ChainstateLoadingError> LoadChainstate(bool fReset,
             chainstate->CoinsErrorCatcher().AddReadErrCallback(coins_error_cb);
         }
 
-        // If necessary, upgrade from older database format.
+        // Refuse to load unsupported database format.
         // This is a no-op if we cleared the coinsviewdb with -reindex or -reindex-chainstate
-        if (!chainstate->CoinsDB().Upgrade()) {
+        if (chainstate->CoinsDB().NeedsUpgrade()) {
             return ChainstateLoadingError::ERROR_CHAINSTATE_UPGRADE_FAILED;
         }
 

src/txdb.cpp

@@ -6,7 +6,6 @@
 #include <txdb.h>
 
 #include <chain.h>
-#include <node/ui_interface.h>
 #include <pow.h>
 #include <random.h>
 #include <shutdown.h>
@@ -18,7 +17,6 @@
 #include <stdint.h>
 
 static constexpr uint8_t DB_COIN{'C'};
-static constexpr uint8_t DB_COINS{'c'};
 static constexpr uint8_t DB_BLOCK_FILES{'f'};
 static constexpr uint8_t DB_BLOCK_INDEX{'b'};
 
@@ -29,6 +27,7 @@ static constexpr uint8_t DB_REINDEX_FLAG{'R'};
 static constexpr uint8_t DB_LAST_BLOCK{'l'};
 
 // Keys used in previous version that might still be found in the DB:
+static constexpr uint8_t DB_COINS{'c'};
 static constexpr uint8_t DB_TXINDEX_BLOCK{'T'};
 //               uint8_t DB_TXINDEX{'t'}
 
@@ -50,6 +49,15 @@ std::optional<bilingual_str> CheckLegacyTxindex(CBlockTreeDB& block_tree_db)
     return std::nullopt;
 }
 
+bool CCoinsViewDB::NeedsUpgrade()
+{
+    std::unique_ptr<CDBIterator> cursor{m_db->NewIterator()};
+    // DB_COINS was deprecated in v0.15.0, commit
+    // 1088b02f0ccd7358d2b7076bb9e122d59d502d02
+    cursor->Seek(std::make_pair(DB_COINS, uint256{}));
+    return cursor->Valid();
+}
+
 namespace {
 
 struct CoinEntry {
@@ -60,7 +68,7 @@ struct CoinEntry {
     SERIALIZE_METHODS(CoinEntry, obj) { READWRITE(obj.key, obj.outpoint->hash, VARINT(obj.outpoint->n)); }
 };
 
-}
+} // namespace
 
 CCoinsViewDB::CCoinsViewDB(fs::path ldb_path, size_t nCacheSize, bool fMemory, bool fWipe) :
     m_db(std::make_unique<CDBWrapper>(ldb_path, nCacheSize, fMemory, fWipe, true)),
@@ -337,125 +345,3 @@ bool CBlockTreeDB::LoadBlockIndexGuts(const Consensus::Params& consensusParams,
 
     return true;
 }
-
-namespace {
-
-//! Legacy class to deserialize pre-pertxout database entries without reindex.
-class CCoins
-{
-public:
-    //! whether transaction is a coinbase
-    bool fCoinBase;
-
-    //! unspent transaction outputs; spent outputs are .IsNull(); spent outputs at the end of the array are dropped
-    std::vector<CTxOut> vout;
-
-    //! at which height this transaction was included in the active block chain
-    int nHeight;
-
-    //! empty constructor
-    CCoins() : fCoinBase(false), vout(0), nHeight(0) { }
-
-    template<typename Stream>
-    void Unserialize(Stream &s) {
-        unsigned int nCode = 0;
-        // version
-        unsigned int nVersionDummy;
-        ::Unserialize(s, VARINT(nVersionDummy));
-        // header code
-        ::Unserialize(s, VARINT(nCode));
-        fCoinBase = nCode & 1;
-        std::vector<bool> vAvail(2, false);
-        vAvail[0] = (nCode & 2) != 0;
-        vAvail[1] = (nCode & 4) != 0;
-        unsigned int nMaskCode = (nCode / 8) + ((nCode & 6) != 0 ? 0 : 1);
-        // spentness bitmask
-        while (nMaskCode > 0) {
-            unsigned char chAvail = 0;
-            ::Unserialize(s, chAvail);
-            for (unsigned int p = 0; p < 8; p++) {
-                bool f = (chAvail & (1 << p)) != 0;
-                vAvail.push_back(f);
-            }
-            if (chAvail != 0)
-                nMaskCode--;
-        }
-        // txouts themself
-        vout.assign(vAvail.size(), CTxOut());
-        for (unsigned int i = 0; i < vAvail.size(); i++) {
-            if (vAvail[i])
-                ::Unserialize(s, Using<TxOutCompression>(vout[i]));
-        }
-        // coinbase height
-        ::Unserialize(s, VARINT_MODE(nHeight, VarIntMode::NONNEGATIVE_SIGNED));
-    }
-};
-
-}
-
-/** Upgrade the database from older formats.
- *
- * Currently implemented: from the per-tx utxo model (0.8..0.14.x) to per-txout.
- */
-bool CCoinsViewDB::Upgrade() {
-    std::unique_ptr<CDBIterator> pcursor(m_db->NewIterator());
-    pcursor->Seek(std::make_pair(DB_COINS, uint256()));
-    if (!pcursor->Valid()) {
-        return true;
-    }
-
-    int64_t count = 0;
-    LogPrintf("Upgrading utxo-set database...\n");
-    LogPrintf("[0%%]..."); /* Continued */
-    uiInterface.ShowProgress(_("Upgrading UTXO database").translated, 0, true);
-    size_t batch_size = 1 << 24;
-    CDBBatch batch(*m_db);
-    int reportDone = 0;
-    std::pair<unsigned char, uint256> key;
-    std::pair<unsigned char, uint256> prev_key = {DB_COINS, uint256()};
-    while (pcursor->Valid()) {
-        if (ShutdownRequested()) {
-            break;
-        }
-        if (pcursor->GetKey(key) && key.first == DB_COINS) {
-            if (count++ % 256 == 0) {
-                uint32_t high = 0x100 * *key.second.begin() + *(key.second.begin() + 1);
-                int percentageDone = (int)(high * 100.0 / 65536.0 + 0.5);
-                uiInterface.ShowProgress(_("Upgrading UTXO database").translated, percentageDone, true);
-                if (reportDone < percentageDone/10) {
-                    // report max. every 10% step
-                    LogPrintf("[%d%%]...", percentageDone); /* Continued */
-                    reportDone = percentageDone/10;
-                }
-            }
-            CCoins old_coins;
-            if (!pcursor->GetValue(old_coins)) {
-                return error("%s: cannot parse CCoins record", __func__);
-            }
-            COutPoint outpoint(key.second, 0);
-            for (size_t i = 0; i < old_coins.vout.size(); ++i) {
-                if (!old_coins.vout[i].IsNull() && !old_coins.vout[i].scriptPubKey.IsUnspendable()) {
-                    Coin newcoin(std::move(old_coins.vout[i]), old_coins.nHeight, old_coins.fCoinBase);
-                    outpoint.n = i;
-                    CoinEntry entry(&outpoint);
-                    batch.Write(entry, newcoin);
-                }
-            }
-            batch.Erase(key);
-            if (batch.SizeEstimate() > batch_size) {
-                m_db->WriteBatch(batch);
-                batch.Clear();
-                m_db->CompactRange(prev_key, key);
-                prev_key = key;
-            }
-            pcursor->Next();
-        } else {
-            break;
-        }
-    }
-    m_db->WriteBatch(batch);
-    m_db->CompactRange({DB_COINS, uint256()}, key);
-    uiInterface.ShowProgress("", 100, false);
-    LogPrintf("[%s].\n", ShutdownRequested() ? "CANCELLED" : "DONE");
-    return !ShutdownRequested();
-}

src/txdb.h

@@ -65,8 +65,8 @@ public:
     bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) override;
     std::unique_ptr<CCoinsViewCursor> Cursor() const override;
 
-    //! Attempt to update from an older database format. Returns whether an error occurred.
-    bool Upgrade();
+    //! Whether an unsupported database format is used.
+    bool NeedsUpgrade();
     size_t EstimateSize() const override;
 
     //! Dynamically alter the underlying leveldb cache size.

test/README.md

@@ -98,7 +98,7 @@ test/functional/test_runner.py --extended
 In order to run backwards compatibility tests, download the previous node binaries:
 
 ```
-test/get_previous_releases.py -b v22.0 v0.21.0 v0.20.1 v0.19.1 v0.18.1 v0.17.2 v0.16.3 v0.15.2
+test/get_previous_releases.py -b v22.0 v0.21.0 v0.20.1 v0.19.1 v0.18.1 v0.17.2 v0.16.3 v0.15.2 v0.14.3
 ```
 
 By default, up to 4 tests will be run in parallel by test_runner. To specify

test/functional/feature_unsupported_utxo_db.py

@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+# Copyright (c) 2022 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Test that unsupported utxo db causes an init error.
+
+Previous releases are required by this test, see test/README.md.
+"""
+
+import shutil
+
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import assert_equal
+
+
+class UnsupportedUtxoDbTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.setup_clean_chain = True
+        self.num_nodes = 2
+
+    def skip_test_if_missing_module(self):
+        self.skip_if_no_previous_releases()
+
+    def setup_network(self):
+        self.add_nodes(
+            self.num_nodes,
+            versions=[
+                140300,  # Last release with previous utxo db format
+                None,  # For MiniWallet, without migration code
+            ],
+        )
+
+    def run_test(self):
+        self.log.info("Create previous version (v0.14.3) utxo db")
+        self.start_node(0)
+        block = self.generate(self.nodes[0], 1, sync_fun=self.no_op)[-1]
+        assert_equal(self.nodes[0].getbestblockhash(), block)
+        assert_equal(self.nodes[0].gettxoutsetinfo()["total_amount"], 50)
+        self.stop_nodes()
+
+        self.log.info("Check init error")
+        legacy_utxos_dir = self.nodes[0].chain_path / "chainstate"
+        legacy_blocks_dir = self.nodes[0].chain_path / "blocks"
+        recent_utxos_dir = self.nodes[1].chain_path / "chainstate"
+        recent_blocks_dir = self.nodes[1].chain_path / "blocks"
+        shutil.copytree(legacy_utxos_dir, recent_utxos_dir)
+        shutil.copytree(legacy_blocks_dir, recent_blocks_dir)
+        self.nodes[1].assert_start_raises_init_error(
+            expected_msg="Error: Unsupported chainstate database format found. "
+            "Please restart with -reindex-chainstate. "
+            "This will rebuild the chainstate database.",
+        )
+
+        self.log.info("Drop legacy utxo db")
+        self.start_node(1, extra_args=["-reindex-chainstate"])
+        assert_equal(self.nodes[1].getbestblockhash(), block)
+        assert_equal(self.nodes[1].gettxoutsetinfo()["total_amount"], 50)
+
+
+if __name__ == "__main__":
+    UnsupportedUtxoDbTest().main()

test/functional/test_runner.py

@@ -306,6 +306,7 @@ BASE_SCRIPTS = [
     'p2p_ping.py',
     'rpc_scantxoutset.py',
     'feature_txindex_compatibility.py',
+    'feature_unsupported_utxo_db.py',
     'feature_logging.py',
     'feature_anchors.py',
     'feature_coinstatsindex.py',

test/get_previous_releases.py

@@ -19,8 +19,12 @@ import subprocess
 import sys
 import hashlib
 
-
 SHA256_SUMS = {
+    "0e2819135366f150d9906e294b61dff58fd1996ebd26c2f8e979d6c0b7a79580": "bitcoin-0.14.3-aarch64-linux-gnu.tar.gz",
+    "d86fc90824a85c38b25c8488115178d5785dbc975f5ff674f9f5716bc8ad6e65": "bitcoin-0.14.3-arm-linux-gnueabihf.tar.gz",
+    "1b0a7408c050e3d09a8be8e21e183ef7ee570385dc41216698cc3ab392a484e7": "bitcoin-0.14.3-osx64.tar.gz",
+    "706e0472dbc933ed2757650d54cbcd780fd3829ebf8f609b32780c7eedebdbc9": "bitcoin-0.14.3-x86_64-linux-gnu.tar.gz",
+    #
     "d40f18b4e43c6e6370ef7db9131f584fbb137276ec2e3dba67a4b267f81cb644": "bitcoin-0.15.2-aarch64-linux-gnu.tar.gz",
     "54fb877a148a6ad189a1e1ab1ff8b11181e58ff2aaf430da55b3fd46ae549a6b": "bitcoin-0.15.2-arm-linux-gnueabihf.tar.gz",
     "87e9340ff3d382d543b2b69112376077f0c8b4f7450d372e83b68f5a1e22b2df": "bitcoin-0.15.2-osx64.tar.gz",