Merge bitcoin/bitcoin#19602: wallet: Migrate legacy wallets to descriptor wallets

53e7ed075c49f853cc845afc7b2f058cabad0cb0 doc: Release notes and other docs for migration (Andrew Chow)
9c44bfe244f35f08ba576d8b979a90dcd68d2c77 Test migratewallet (Andrew Chow)
0b26e7cdf2659fd8b54d21fd2bd749f9f3e87af8 descriptors: addr() and raw() should return false for ToPrivateString (Andrew Chow)
31764c3f872f4f01b48d50585f86e97c41554954 Add migratewallet RPC (Andrew Chow)
0bf7b38bff422e7413bcd3dc0abe2568dd918ddc Implement MigrateLegacyToDescriptor (Andrew Chow)
e7b16f925ae5b117e8b74ce814b63e19b19b50f4 Implement MigrateToSQLite (Andrew Chow)
5b62f095e790a0d4e2a70ece89465b64fc68358a wallet: Refactor SetupDescSPKMs to take CExtKey (Andrew Chow)
22401f17e026ead4bc3fe96967eec56a719a4f75 Implement LegacyScriptPubKeyMan::DeleteRecords (Andrew Chow)
35f428fae68ad974abdce0fa905148f620a9443c Implement LegacyScriptPubKeyMan::MigrateToDescriptor (Andrew Chow)
ea1ab390e4dac128e3a37d4884528c3f4128ed83 scriptpubkeyman: Implement GetScriptPubKeys in Legacy (Andrew Chow)
e664af29760527e75cd7e290be5f102b6d29ebee Apply label to all scriptPubKeys of imported combo() (Andrew Chow)

Pull request description:

  This PR adds a new `migratewallet` RPC which migrates a legacy wallet to a descriptor wallet. Migrated wallets will need a new backup. If a wallet has watchonly stuff in it, a new watchonly descriptor wallet will be created containing those watchonly things. The related transactions, labels, and descriptors for those watchonly things will be removed from the original wallet. Migrated wallets will not have any of the legacy things be available for fetching from `getnewaddress` or `getrawchangeaddress`. Wallets that have private keys enabled will have newly generated descriptors. Wallets with private keys disabled will not have any active `ScriptPubKeyMan`s.

  For the basic HD wallet case of just generated keys, in addition to the standard descriptor wallet descriptors using the master key derived from the pre-existing hd seed, the migration will also create 3 descriptors for each HD chain in: a ranged combo external, a ranged combo internal, and a single key combo for the seed (the seed is a valid key that we can receive coins at!). The migrated wallet will then have newly generated descriptors as the active `ScriptPubKeyMan`s. This is equivalent to creating a new descriptor wallet and importing the 3 descriptors for each HD chain. For wallets containing non-HD keys, each key will have its own combo descriptor.

  There are also tests.

ACKs for top commit:
  Sjors:
    tACK 53e7ed075c49f853cc845afc7b2f058cabad0cb0
  w0xlt:
    reACK https://github.com/bitcoin/bitcoin/commit/53e7ed075c49f853cc845afc7b2f058cabad0cb0

Tree-SHA512: c0c003694ca2e17064922d08e8464278d314e970efb7df874b4fe04ec5d124c7206409ca701c65c099d17779ab2136ae63f1da2a9dba39b45f6d62cf93b5c60a

1 files changed, 499 insertions, 20 deletions

diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 69a151d5c8..b25488f6a1 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -3434,6 +3434,29 @@ void CWallet::LoadDescriptorScriptPubKeyMan(uint256 id, WalletDescriptor& desc)
     }
 }
 
+void CWallet::SetupDescriptorScriptPubKeyMans(const CExtKey& master_key)
+{
+    AssertLockHeld(cs_wallet);
+
+    for (bool internal : {false, true}) {
+        for (OutputType t : OUTPUT_TYPES) {
+            auto spk_manager = std::unique_ptr<DescriptorScriptPubKeyMan>(new DescriptorScriptPubKeyMan(*this));
+            if (IsCrypted()) {
+                if (IsLocked()) {
+                    throw std::runtime_error(std::string(__func__) + ": Wallet is locked, cannot setup new descriptors");
+                }
+                if (!spk_manager->CheckDecryptionKey(vMasterKey) && !spk_manager->Encrypt(vMasterKey, nullptr)) {
+                    throw std::runtime_error(std::string(__func__) + ": Could not encrypt new descriptors");
+                }
+            }
+            spk_manager->SetupDescriptorGeneration(master_key, t, internal);
+            uint256 id = spk_manager->GetID();
+            m_spk_managers[id] = std::move(spk_manager);
+            AddActiveScriptPubKeyMan(id, t, internal);
+        }
+    }
+}
+
 void CWallet::SetupDescriptorScriptPubKeyMans()
 {
     AssertLockHeld(cs_wallet);
@@ -3449,23 +3472,7 @@ void CWallet::SetupDescriptorScriptPubKeyMans()
         CExtKey master_key;
         master_key.SetSeed(seed_key);
 
-        for (bool internal : {false, true}) {
-            for (OutputType t : OUTPUT_TYPES) {
-                auto spk_manager = std::unique_ptr<DescriptorScriptPubKeyMan>(new DescriptorScriptPubKeyMan(*this));
-                if (IsCrypted()) {
-                    if (IsLocked()) {
-                        throw std::runtime_error(std::string(__func__) + ": Wallet is locked, cannot setup new descriptors");
-                    }
-                    if (!spk_manager->CheckDecryptionKey(vMasterKey) && !spk_manager->Encrypt(vMasterKey, nullptr)) {
-                        throw std::runtime_error(std::string(__func__) + ": Could not encrypt new descriptors");
-                    }
-                }
-                spk_manager->SetupDescriptorGeneration(master_key, t, internal);
-                uint256 id = spk_manager->GetID();
-                m_spk_managers[id] = std::move(spk_manager);
-                AddActiveScriptPubKeyMan(id, t, internal);
-            }
-        }
+        SetupDescriptorScriptPubKeyMans(master_key);
     } else {
         ExternalSigner signer = ExternalSignerScriptPubKeyMan::GetExternalSigner();
 
@@ -3633,9 +3640,13 @@ ScriptPubKeyMan* CWallet::AddWalletDescriptor(WalletDescriptor& desc, const Flat
             return nullptr;
         }
 
-        CTxDestination dest;
-        if (!internal && ExtractDestination(script_pub_keys.at(0), dest)) {
-            SetAddressBook(dest, label, "receive");
+        if (!internal) {
+            for (const auto& script : script_pub_keys) {
+                CTxDestination dest;
+                if (ExtractDestination(script, dest)) {
+                    SetAddressBook(dest, label, "receive");
+                }
+            }
         }
     }
 
@@ -3644,4 +3655,472 @@ ScriptPubKeyMan* CWallet::AddWalletDescriptor(WalletDescriptor& desc, const Flat
 
     return spk_man;
 }
+
+bool CWallet::MigrateToSQLite(bilingual_str& error)
+{
+    AssertLockHeld(cs_wallet);
+
+    WalletLogPrintf("Migrating wallet storage database from BerkeleyDB to SQLite.\n");
+
+    if (m_database->Format() == "sqlite") {
+        error = _("Error: This wallet already uses SQLite");
+        return false;
+    }
+
+    // Get all of the records for DB type migration
+    std::unique_ptr<DatabaseBatch> batch = m_database->MakeBatch();
+    std::vector<std::pair<SerializeData, SerializeData>> records;
+    if (!batch->StartCursor()) {
+        error = _("Error: Unable to begin reading all records in the database");
+        return false;
+    }
+    bool complete = false;
+    while (true) {
+        CDataStream ss_key(SER_DISK, CLIENT_VERSION);
+        CDataStream ss_value(SER_DISK, CLIENT_VERSION);
+        bool ret = batch->ReadAtCursor(ss_key, ss_value, complete);
+        if (!ret) {
+            break;
+        }
+        SerializeData key(ss_key.begin(), ss_key.end());
+        SerializeData value(ss_value.begin(), ss_value.end());
+        records.emplace_back(key, value);
+    }
+    batch->CloseCursor();
+    batch.reset();
+    if (!complete) {
+        error = _("Error: Unable to read all records in the database");
+        return false;
+    }
+
+    // Close this database and delete the file
+    fs::path db_path = fs::PathFromString(m_database->Filename());
+    fs::path db_dir = db_path.parent_path();
+    m_database->Close();
+    fs::remove(db_path);
+
+    // Make new DB
+    DatabaseOptions opts;
+    opts.require_create = true;
+    opts.require_format = DatabaseFormat::SQLITE;
+    DatabaseStatus db_status;
+    std::unique_ptr<WalletDatabase> new_db = MakeDatabase(db_dir, opts, db_status, error);
+    assert(new_db); // This is to prevent doing anything further with this wallet. The original file was deleted, but a backup exists.
+    m_database.reset();
+    m_database = std::move(new_db);
+
+    // Write existing records into the new DB
+    batch = m_database->MakeBatch();
+    bool began = batch->TxnBegin();
+    assert(began); // This is a critical error, the new db could not be written to. The original db exists as a backup, but we should not continue execution.
+    for (const auto& [key, value] : records) {
+        CDataStream ss_key(key, SER_DISK, CLIENT_VERSION);
+        CDataStream ss_value(value, SER_DISK, CLIENT_VERSION);
+        if (!batch->Write(ss_key, ss_value)) {
+            batch->TxnAbort();
+            m_database->Close();
+            fs::remove(m_database->Filename());
+            assert(false); // This is a critical error, the new db could not be written to. The original db exists as a backup, but we should not continue execution.
+        }
+    }
+    bool committed = batch->TxnCommit();
+    assert(committed); // This is a critical error, the new db could not be written to. The original db exists as a backup, but we should not continue execution.
+    return true;
+}
+
+std::optional<MigrationData> CWallet::GetDescriptorsForLegacy(bilingual_str& error) const
+{
+    AssertLockHeld(cs_wallet);
+
+    LegacyScriptPubKeyMan* legacy_spkm = GetLegacyScriptPubKeyMan();
+    if (!legacy_spkm) {
+        error = _("Error: This wallet is already a descriptor wallet");
+        return std::nullopt;
+    }
+
+    std::optional<MigrationData> res = legacy_spkm->MigrateToDescriptor();
+    if (res == std::nullopt) {
+        error = _("Error: Unable to produce descriptors for this legacy wallet. Make sure the wallet is unlocked first");
+        return std::nullopt;
+    }
+    return res;
+}
+
+bool CWallet::ApplyMigrationData(MigrationData& data, bilingual_str& error)
+{
+    AssertLockHeld(cs_wallet);
+
+    LegacyScriptPubKeyMan* legacy_spkm = GetLegacyScriptPubKeyMan();
+    if (!legacy_spkm) {
+        error = _("Error: This wallet is already a descriptor wallet");
+        return false;
+    }
+
+    for (auto& desc_spkm : data.desc_spkms) {
+        if (m_spk_managers.count(desc_spkm->GetID()) > 0) {
+            error = _("Error: Duplicate descriptors created during migration. Your wallet may be corrupted.");
+            return false;
+        }
+        m_spk_managers[desc_spkm->GetID()] = std::move(desc_spkm);
+    }
+
+    // Remove the LegacyScriptPubKeyMan from disk
+    if (!legacy_spkm->DeleteRecords()) {
+        return false;
+    }
+
+    // Remove the LegacyScriptPubKeyMan from memory
+    m_spk_managers.erase(legacy_spkm->GetID());
+    m_external_spk_managers.clear();
+    m_internal_spk_managers.clear();
+
+    // Setup new descriptors
+    SetWalletFlag(WALLET_FLAG_DESCRIPTORS);
+    if (!IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
+        // Use the existing master key if we have it
+        if (data.master_key.key.IsValid()) {
+            SetupDescriptorScriptPubKeyMans(data.master_key);
+        } else {
+            // Setup with a new seed if we don't.
+            SetupDescriptorScriptPubKeyMans();
+        }
+    }
+
+    // Check if the transactions in the wallet are still ours. Either they belong here, or they belong in the watchonly wallet.
+    // We need to go through these in the tx insertion order so that lookups to spends works.
+    std::vector<uint256> txids_to_delete;
+    for (const auto& [_pos, wtx] : wtxOrdered) {
+        if (!IsMine(*wtx->tx) && !IsFromMe(*wtx->tx)) {
+            // Check it is the watchonly wallet's
+            // solvable_wallet doesn't need to be checked because transactions for those scripts weren't being watched for
+            if (data.watchonly_wallet) {
+                LOCK(data.watchonly_wallet->cs_wallet);
+                if (data.watchonly_wallet->IsMine(*wtx->tx) || data.watchonly_wallet->IsFromMe(*wtx->tx)) {
+                    // Add to watchonly wallet
+                    if (!data.watchonly_wallet->AddToWallet(wtx->tx, wtx->m_state)) {
+                        error = _("Error: Could not add watchonly tx to watchonly wallet");
+                        return false;
+                    }
+                    // Mark as to remove from this wallet
+                    txids_to_delete.push_back(wtx->GetHash());
+                    continue;
+                }
+            }
+            // Both not ours and not in the watchonly wallet
+            error = strprintf(_("Error: Transaction %s in wallet cannot be identified to belong to migrated wallets"), wtx->GetHash().GetHex());
+            return false;
+        }
+    }
+    // Do the removes
+    if (txids_to_delete.size() > 0) {
+        std::vector<uint256> deleted_txids;
+        if (ZapSelectTx(txids_to_delete, deleted_txids) != DBErrors::LOAD_OK) {
+            error = _("Error: Could not delete watchonly transactions");
+            return false;
+        }
+        if (deleted_txids != txids_to_delete) {
+            error = _("Error: Not all watchonly txs could be deleted");
+            return false;
+        }
+        // Tell the GUI of each tx
+        for (const uint256& txid : deleted_txids) {
+            NotifyTransactionChanged(txid, CT_UPDATED);
+        }
+    }
+
+    // Check the address book data in the same way we did for transactions
+    std::vector<CTxDestination> dests_to_delete;
+    for (const auto& addr_pair : m_address_book) {
+        // Labels applied to receiving addresses should go based on IsMine
+        if (addr_pair.second.purpose == "receive") {
+            if (!IsMine(addr_pair.first)) {
+                // Check the address book data is the watchonly wallet's
+                if (data.watchonly_wallet) {
+                    LOCK(data.watchonly_wallet->cs_wallet);
+                    if (data.watchonly_wallet->IsMine(addr_pair.first)) {
+                        // Add to the watchonly. Preserve the labels, purpose, and change-ness
+                        std::string label = addr_pair.second.GetLabel();
+                        std::string purpose = addr_pair.second.purpose;
+                        if (!purpose.empty()) {
+                            data.watchonly_wallet->m_address_book[addr_pair.first].purpose = purpose;
+                        }
+                        if (!addr_pair.second.IsChange()) {
+                            data.watchonly_wallet->m_address_book[addr_pair.first].SetLabel(label);
+                        }
+                        dests_to_delete.push_back(addr_pair.first);
+                        continue;
+                    }
+                }
+                if (data.solvable_wallet) {
+                    LOCK(data.solvable_wallet->cs_wallet);
+                    if (data.solvable_wallet->IsMine(addr_pair.first)) {
+                        // Add to the solvable. Preserve the labels, purpose, and change-ness
+                        std::string label = addr_pair.second.GetLabel();
+                        std::string purpose = addr_pair.second.purpose;
+                        if (!purpose.empty()) {
+                            data.solvable_wallet->m_address_book[addr_pair.first].purpose = purpose;
+                        }
+                        if (!addr_pair.second.IsChange()) {
+                            data.solvable_wallet->m_address_book[addr_pair.first].SetLabel(label);
+                        }
+                        dests_to_delete.push_back(addr_pair.first);
+                        continue;
+                    }
+                }
+                // Not ours, not in watchonly wallet, and not in solvable
+                error = _("Error: Address book data in wallet cannot be identified to belong to migrated wallets");
+                return false;
+            }
+        } else {
+            // Labels for everything else (send) should be cloned to all
+            if (data.watchonly_wallet) {
+                LOCK(data.watchonly_wallet->cs_wallet);
+                // Add to the watchonly. Preserve the labels, purpose, and change-ness
+                std::string label = addr_pair.second.GetLabel();
+                std::string purpose = addr_pair.second.purpose;
+                if (!purpose.empty()) {
+                    data.watchonly_wallet->m_address_book[addr_pair.first].purpose = purpose;
+                }
+                if (!addr_pair.second.IsChange()) {
+                    data.watchonly_wallet->m_address_book[addr_pair.first].SetLabel(label);
+                }
+                continue;
+            }
+            if (data.solvable_wallet) {
+                LOCK(data.solvable_wallet->cs_wallet);
+                // Add to the solvable. Preserve the labels, purpose, and change-ness
+                std::string label = addr_pair.second.GetLabel();
+                std::string purpose = addr_pair.second.purpose;
+                if (!purpose.empty()) {
+                    data.solvable_wallet->m_address_book[addr_pair.first].purpose = purpose;
+                }
+                if (!addr_pair.second.IsChange()) {
+                    data.solvable_wallet->m_address_book[addr_pair.first].SetLabel(label);
+                }
+                continue;
+            }
+        }
+    }
+    // Remove the things to delete
+    if (dests_to_delete.size() > 0) {
+        for (const auto& dest : dests_to_delete) {
+            if (!DelAddressBook(dest)) {
+                error = _("Error: Unable to remove watchonly address book data");
+                return false;
+            }
+        }
+    }
+
+    // Connect the SPKM signals
+    ConnectScriptPubKeyManNotifiers();
+    NotifyCanGetAddressesChanged();
+
+    WalletLogPrintf("Wallet migration complete.\n");
+
+    return true;
+}
+
+bool DoMigration(CWallet& wallet, WalletContext& context, bilingual_str& error, MigrationResult& res) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet)
+{
+    AssertLockHeld(wallet.cs_wallet);
+
+    // Get all of the descriptors from the legacy wallet
+    std::optional<MigrationData> data = wallet.GetDescriptorsForLegacy(error);
+    if (data == std::nullopt) return false;
+
+    // Create the watchonly and solvable wallets if necessary
+    if (data->watch_descs.size() > 0 || data->solvable_descs.size() > 0) {
+        DatabaseOptions options;
+        options.require_existing = false;
+        options.require_create = true;
+
+        // Make the wallets
+        options.create_flags = WALLET_FLAG_DISABLE_PRIVATE_KEYS | WALLET_FLAG_BLANK_WALLET | WALLET_FLAG_DESCRIPTORS;
+        if (wallet.IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE)) {
+            options.create_flags |= WALLET_FLAG_AVOID_REUSE;
+        }
+        if (wallet.IsWalletFlagSet(WALLET_FLAG_KEY_ORIGIN_METADATA)) {
+            options.create_flags |= WALLET_FLAG_KEY_ORIGIN_METADATA;
+        }
+        if (data->watch_descs.size() > 0) {
+            wallet.WalletLogPrintf("Making a new watchonly wallet containing the watched scripts\n");
+
+            DatabaseStatus status;
+            std::vector<bilingual_str> warnings;
+            std::string wallet_name = wallet.GetName() + "_watchonly";
+            data->watchonly_wallet = CreateWallet(context, wallet_name, std::nullopt, options, status, error, warnings);
+            if (status != DatabaseStatus::SUCCESS) {
+                error = _("Error: Failed to create new watchonly wallet");
+                return false;
+            }
+            res.watchonly_wallet = data->watchonly_wallet;
+            LOCK(data->watchonly_wallet->cs_wallet);
+
+            // Parse the descriptors and add them to the new wallet
+            for (const auto& [desc_str, creation_time] : data->watch_descs) {
+                // Parse the descriptor
+                FlatSigningProvider keys;
+                std::string parse_err;
+                std::unique_ptr<Descriptor> desc = Parse(desc_str, keys, parse_err, /* require_checksum */ true);
+                assert(desc); // It shouldn't be possible to have the LegacyScriptPubKeyMan make an invalid descriptor
+                assert(!desc->IsRange()); // It shouldn't be possible to have LegacyScriptPubKeyMan make a ranged watchonly descriptor
+
+                // Add to the wallet
+                WalletDescriptor w_desc(std::move(desc), creation_time, 0, 0, 0);
+                data->watchonly_wallet->AddWalletDescriptor(w_desc, keys, "", false);
+            }
+
+            // Add the wallet to settings
+            UpdateWalletSetting(*context.chain, wallet_name, /*load_on_startup=*/true, warnings);
+        }
+        if (data->solvable_descs.size() > 0) {
+            wallet.WalletLogPrintf("Making a new watchonly wallet containing the unwatched solvable scripts\n");
+
+            DatabaseStatus status;
+            std::vector<bilingual_str> warnings;
+            std::string wallet_name = wallet.GetName() + "_solvables";
+            data->solvable_wallet = CreateWallet(context, wallet_name, std::nullopt, options, status, error, warnings);
+            if (status != DatabaseStatus::SUCCESS) {
+                error = _("Error: Failed to create new watchonly wallet");
+                return false;
+            }
+            res.solvables_wallet = data->solvable_wallet;
+            LOCK(data->solvable_wallet->cs_wallet);
+
+            // Parse the descriptors and add them to the new wallet
+            for (const auto& [desc_str, creation_time] : data->solvable_descs) {
+                // Parse the descriptor
+                FlatSigningProvider keys;
+                std::string parse_err;
+                std::unique_ptr<Descriptor> desc = Parse(desc_str, keys, parse_err, /* require_checksum */ true);
+                assert(desc); // It shouldn't be possible to have the LegacyScriptPubKeyMan make an invalid descriptor
+                assert(!desc->IsRange()); // It shouldn't be possible to have LegacyScriptPubKeyMan make a ranged watchonly descriptor
+
+                // Add to the wallet
+                WalletDescriptor w_desc(std::move(desc), creation_time, 0, 0, 0);
+                data->solvable_wallet->AddWalletDescriptor(w_desc, keys, "", false);
+            }
+
+            // Add the wallet to settings
+            UpdateWalletSetting(*context.chain, wallet_name, /*load_on_startup=*/true, warnings);
+        }
+    }
+
+    // Add the descriptors to wallet, remove LegacyScriptPubKeyMan, and cleanup txs and address book data
+    if (!wallet.ApplyMigrationData(*data, error)) {
+        return false;
+    }
+    return true;
+}
+
+util::Result<MigrationResult> MigrateLegacyToDescriptor(std::shared_ptr<CWallet>&& wallet, WalletContext& context)
+{
+    MigrationResult res;
+    bilingual_str error;
+    std::vector<bilingual_str> warnings;
+
+    // Make a backup of the DB
+    std::string wallet_name = wallet->GetName();
+    fs::path this_wallet_dir = fs::absolute(fs::PathFromString(wallet->GetDatabase().Filename())).parent_path();
+    fs::path backup_filename = fs::PathFromString(strprintf("%s-%d.legacy.bak", wallet_name, GetTime()));
+    fs::path backup_path = this_wallet_dir / backup_filename;
+    if (!wallet->BackupWallet(fs::PathToString(backup_path))) {
+        return util::Error{_("Error: Unable to make a backup of your wallet")};
+    }
+    res.backup_path = backup_path;
+
+    // Unload the wallet so that nothing else tries to use it while we're changing it
+    if (!RemoveWallet(context, wallet, /*load_on_start=*/std::nullopt, warnings)) {
+        return util::Error{_("Unable to unload the wallet before migrating")};
+    }
+    UnloadWallet(std::move(wallet));
+
+    // Load the wallet but only in the context of this function.
+    // No signals should be connected nor should anything else be aware of this wallet
+    WalletContext empty_context;
+    empty_context.args = context.args;
+    DatabaseOptions options;
+    options.require_existing = true;
+    DatabaseStatus status;
+    std::unique_ptr<WalletDatabase> database = MakeWalletDatabase(wallet_name, options, status, error);
+    if (!database) {
+        return util::Error{Untranslated("Wallet file verification failed.") + Untranslated(" ") + error};
+    }
+
+    std::shared_ptr<CWallet> local_wallet = CWallet::Create(empty_context, wallet_name, std::move(database), options.create_flags, error, warnings);
+    if (!local_wallet) {
+        return util::Error{Untranslated("Wallet loading failed.") + Untranslated(" ") + error};
+    }
+
+    bool success = false;
+    {
+        LOCK(local_wallet->cs_wallet);
+
+        // First change to using SQLite
+        if (!local_wallet->MigrateToSQLite(error)) return util::Error{error};
+
+        // Do the migration, and cleanup if it fails
+        success = DoMigration(*local_wallet, context, error, res);
+    }
+
+    if (success) {
+        // Migration successful, unload the wallet locally, then reload it.
+        assert(local_wallet.use_count() == 1);
+        local_wallet.reset();
+        LoadWallet(context, wallet_name, /*load_on_start=*/std::nullopt, options, status, error, warnings);
+        res.wallet_name = wallet_name;
+    } else {
+        // Migration failed, cleanup
+        // Copy the backup to the actual wallet dir
+        fs::path temp_backup_location = fsbridge::AbsPathJoin(GetWalletDir(), backup_filename);
+        fs::copy_file(backup_path, temp_backup_location, fs::copy_options::none);
+
+        // Remember this wallet's walletdir to remove after unloading
+        std::vector<fs::path> wallet_dirs;
+        wallet_dirs.push_back(fs::PathFromString(local_wallet->GetDatabase().Filename()).parent_path());
+
+        // Unload the wallet locally
+        assert(local_wallet.use_count() == 1);
+        local_wallet.reset();
+
+        // Make list of wallets to cleanup
+        std::vector<std::shared_ptr<CWallet>> created_wallets;
+        created_wallets.push_back(std::move(res.watchonly_wallet));
+        created_wallets.push_back(std::move(res.solvables_wallet));
+
+        // Get the directories to remove after unloading
+        for (std::shared_ptr<CWallet>& w : created_wallets) {
+            wallet_dirs.push_back(fs::PathFromString(w->GetDatabase().Filename()).parent_path());
+        }
+
+        // Unload the wallets
+        for (std::shared_ptr<CWallet>& w : created_wallets) {
+            if (!RemoveWallet(context, w, /*load_on_start=*/false)) {
+                error += _("\nUnable to cleanup failed migration");
+                return util::Error{error};
+            }
+            UnloadWallet(std::move(w));
+        }
+
+        // Delete the wallet directories
+        for (fs::path& dir : wallet_dirs) {
+            fs::remove_all(dir);
+        }
+
+        // Restore the backup
+        DatabaseStatus status;
+        std::vector<bilingual_str> warnings;
+        if (!RestoreWallet(context, temp_backup_location, wallet_name, /*load_on_start=*/std::nullopt, status, error, warnings)) {
+            error += _("\nUnable to restore backup of wallet.");
+            return util::Error{error};
+        }
+
+        // Move the backup to the wallet dir
+        fs::copy_file(temp_backup_location, backup_path, fs::copy_options::none);
+        fs::remove(temp_backup_location);
+
+        return util::Error{error};
+    }
+    return res;
+}
 } // namespace wallet