bitcoin/src/wallet/load.cpp
ismaelsadeeq 1b41d45d46
wallet: bugfix: ensure atomicity in settings updates
- Settings updates were not thread-safe, as they were executed in
  three separate steps:

  1) Obtain settings value while acquiring the settings lock.
  2) Modify settings value.
  3) Overwrite settings value while acquiring the settings lock.

  This approach allowed concurrent threads to modify the same base value
  simultaneously, leading to data loss. When this occurred, the final
  settings state would only reflect the changes from the last thread
  that completed the operation, overwriting updates from other threads.

  Fix this by making the settings update operation atomic.

- Add test coverage for this behavior.

Co-authored-by: furszy <matiasfurszyfer@protonmail.com>
2024-08-26 13:41:56 +01:00

185 lines
7.0 KiB
C++

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2022 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include <wallet/load.h>
#include <common/args.h>
#include <interfaces/chain.h>
#include <scheduler.h>
#include <util/check.h>
#include <util/fs.h>
#include <util/string.h>
#include <util/translation.h>
#include <wallet/context.h>
#include <wallet/spend.h>
#include <wallet/wallet.h>
#include <wallet/walletdb.h>
#include <univalue.h>
#include <system_error>
using util::Join;
namespace wallet {
bool VerifyWallets(WalletContext& context)
{
interfaces::Chain& chain = *context.chain;
ArgsManager& args = *Assert(context.args);
if (args.IsArgSet("-walletdir")) {
const fs::path wallet_dir{args.GetPathArg("-walletdir")};
std::error_code error;
// The canonical path cleans the path, preventing >1 Berkeley environment instances for the same directory
// It also lets the fs::exists and fs::is_directory checks below pass on windows, since they return false
// if a path has trailing slashes, and it strips trailing slashes.
fs::path canonical_wallet_dir = fs::canonical(wallet_dir, error);
if (error || !fs::exists(canonical_wallet_dir)) {
chain.initError(strprintf(_("Specified -walletdir \"%s\" does not exist"), fs::PathToString(wallet_dir)));
return false;
} else if (!fs::is_directory(canonical_wallet_dir)) {
chain.initError(strprintf(_("Specified -walletdir \"%s\" is not a directory"), fs::PathToString(wallet_dir)));
return false;
// The canonical path transforms relative paths into absolute ones, so we check the non-canonical version
} else if (!wallet_dir.is_absolute()) {
chain.initError(strprintf(_("Specified -walletdir \"%s\" is a relative path"), fs::PathToString(wallet_dir)));
return false;
}
args.ForceSetArg("-walletdir", fs::PathToString(canonical_wallet_dir));
}
LogPrintf("Using wallet directory %s\n", fs::PathToString(GetWalletDir()));
chain.initMessage(_("Verifying wallet(s)…").translated);
// For backwards compatibility if an unnamed top level wallet exists in the
// wallets directory, include it in the default list of wallets to load.
if (!args.IsArgSet("wallet")) {
DatabaseOptions options;
DatabaseStatus status;
ReadDatabaseArgs(args, options);
bilingual_str error_string;
options.require_existing = true;
options.verify = false;
if (MakeWalletDatabase("", options, status, error_string)) {
common::SettingsValue wallets(common::SettingsValue::VARR);
wallets.push_back(""); // Default wallet name is ""
// Pass write=false because no need to write file and probably
// better not to. If unnamed wallet needs to be added next startup
// and the setting is empty, this code will just run again.
chain.overwriteRwSetting("wallet", wallets, /*write=*/false);
}
}
// Keep track of each wallet absolute path to detect duplicates.
std::set<fs::path> wallet_paths;
for (const auto& wallet : chain.getSettingsList("wallet")) {
const auto& wallet_file = wallet.get_str();
const fs::path path = fsbridge::AbsPathJoin(GetWalletDir(), fs::PathFromString(wallet_file));
if (!wallet_paths.insert(path).second) {
chain.initWarning(strprintf(_("Ignoring duplicate -wallet %s."), wallet_file));
continue;
}
DatabaseOptions options;
DatabaseStatus status;
ReadDatabaseArgs(args, options);
options.require_existing = true;
options.verify = true;
bilingual_str error_string;
if (!MakeWalletDatabase(wallet_file, options, status, error_string)) {
if (status == DatabaseStatus::FAILED_NOT_FOUND) {
chain.initWarning(Untranslated(strprintf("Skipping -wallet path that doesn't exist. %s", error_string.original)));
} else {
chain.initError(error_string);
return false;
}
}
}
return true;
}
bool LoadWallets(WalletContext& context)
{
interfaces::Chain& chain = *context.chain;
try {
std::set<fs::path> wallet_paths;
for (const auto& wallet : chain.getSettingsList("wallet")) {
const auto& name = wallet.get_str();
if (!wallet_paths.insert(fs::PathFromString(name)).second) {
continue;
}
DatabaseOptions options;
DatabaseStatus status;
ReadDatabaseArgs(*context.args, options);
options.require_existing = true;
options.verify = false; // No need to verify, assuming verified earlier in VerifyWallets()
bilingual_str error;
std::vector<bilingual_str> warnings;
std::unique_ptr<WalletDatabase> database = MakeWalletDatabase(name, options, status, error);
if (!database && status == DatabaseStatus::FAILED_NOT_FOUND) {
continue;
}
chain.initMessage(_("Loading wallet…").translated);
std::shared_ptr<CWallet> pwallet = database ? CWallet::Create(context, name, std::move(database), options.create_flags, error, warnings) : nullptr;
if (!warnings.empty()) chain.initWarning(Join(warnings, Untranslated("\n")));
if (!pwallet) {
chain.initError(error);
return false;
}
NotifyWalletLoaded(context, pwallet);
AddWallet(context, pwallet);
}
return true;
} catch (const std::runtime_error& e) {
chain.initError(Untranslated(e.what()));
return false;
}
}
void StartWallets(WalletContext& context)
{
for (const std::shared_ptr<CWallet>& pwallet : GetWallets(context)) {
pwallet->postInitProcess();
}
// Schedule periodic wallet flushes and tx rebroadcasts
if (context.args->GetBoolArg("-flushwallet", DEFAULT_FLUSHWALLET)) {
context.scheduler->scheduleEvery([&context] { MaybeCompactWalletDB(context); }, 500ms);
}
context.scheduler->scheduleEvery([&context] { MaybeResendWalletTxs(context); }, 1min);
}
void FlushWallets(WalletContext& context)
{
for (const std::shared_ptr<CWallet>& pwallet : GetWallets(context)) {
pwallet->Flush();
}
}
void StopWallets(WalletContext& context)
{
for (const std::shared_ptr<CWallet>& pwallet : GetWallets(context)) {
pwallet->Close();
}
}
void UnloadWallets(WalletContext& context)
{
auto wallets = GetWallets(context);
while (!wallets.empty()) {
auto wallet = wallets.back();
wallets.pop_back();
std::vector<bilingual_str> warnings;
RemoveWallet(context, wallet, /* load_on_start= */ std::nullopt, warnings);
WaitForDeleteWallet(std::move(wallet));
}
}
} // namespace wallet