fault_injection_test_env.cc
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
//
// Copyright 2014 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
// This test uses a custom Env to keep track of the state of a filesystem as of
// the last "sync". It then checks for data loss errors by purposely dropping
// file data (or entire files) not protected by a "sync".
#include "util/fault_injection_test_env.h"
#include <functional>
#include <utility>
namespace rocksdb {
// Assume a filename, and not a directory name like "/foo/bar/"
std::string GetDirName(const std::string filename) {
size_t found = filename.find_last_of("/\\");
if (found == std::string::npos) {
return "";
} else {
return filename.substr(0, found);
}
}
// A basic file truncation function suitable for this test.
Status Truncate(Env* env, const std::string& filename, uint64_t length) {
std::unique_ptr<SequentialFile> orig_file;
const EnvOptions options;
Status s = env->NewSequentialFile(filename, &orig_file, options);
if (!s.ok()) {
fprintf(stderr, "Cannot open file %s for truncation: %s\n",
filename.c_str(), s.ToString().c_str());
return s;
}
std::unique_ptr<char[]> scratch(new char[length]);
rocksdb::Slice result;
s = orig_file->Read(length, &result, scratch.get());
#ifdef OS_WIN
orig_file.reset();
#endif
if (s.ok()) {
std::string tmp_name = GetDirName(filename) + "/truncate.tmp";
std::unique_ptr<WritableFile> tmp_file;
s = env->NewWritableFile(tmp_name, &tmp_file, options);
if (s.ok()) {
s = tmp_file->Append(result);
if (s.ok()) {
s = env->RenameFile(tmp_name, filename);
} else {
fprintf(stderr, "Cannot rename file %s to %s: %s\n", tmp_name.c_str(),
filename.c_str(), s.ToString().c_str());
env->DeleteFile(tmp_name);
}
}
}
if (!s.ok()) {
fprintf(stderr, "Cannot truncate file %s: %s\n", filename.c_str(),
s.ToString().c_str());
}
return s;
}
// Trim the tailing "/" in the end of `str`
std::string TrimDirname(const std::string& str) {
size_t found = str.find_last_not_of("/");
if (found == std::string::npos) {
return str;
}
return str.substr(0, found + 1);
}
// Return pair <parent directory name, file name> of a full path.
std::pair<std::string, std::string> GetDirAndName(const std::string& name) {
std::string dirname = GetDirName(name);
std::string fname = name.substr(dirname.size() + 1);
return std::make_pair(dirname, fname);
}
Status FileState::DropUnsyncedData(Env* env) const {
ssize_t sync_pos = pos_at_last_sync_ == -1 ? 0 : pos_at_last_sync_;
return Truncate(env, filename_, sync_pos);
}
Status FileState::DropRandomUnsyncedData(Env* env, Random* rand) const {
ssize_t sync_pos = pos_at_last_sync_ == -1 ? 0 : pos_at_last_sync_;
assert(pos_ >= sync_pos);
int range = static_cast<int>(pos_ - sync_pos);
uint64_t truncated_size =
static_cast<uint64_t>(sync_pos) + rand->Uniform(range);
return Truncate(env, filename_, truncated_size);
}
Status TestDirectory::Fsync() {
env_->SyncDir(dirname_);
return dir_->Fsync();
}
TestWritableFile::TestWritableFile(const std::string& fname,
std::unique_ptr<WritableFile>&& f,
FaultInjectionTestEnv* env)
: state_(fname),
target_(std::move(f)),
writable_file_opened_(true),
env_(env) {
assert(target_ != nullptr);
state_.pos_ = 0;
}
TestWritableFile::~TestWritableFile() {
if (writable_file_opened_) {
Close();
}
}
Status TestWritableFile::Append(const Slice& data) {
if (!env_->IsFilesystemActive()) {
return env_->GetError();
}
Status s = target_->Append(data);
if (s.ok()) {
state_.pos_ += data.size();
env_->WritableFileAppended(state_);
}
return s;
}
Status TestWritableFile::Close() {
writable_file_opened_ = false;
Status s = target_->Close();
if (s.ok()) {
env_->WritableFileClosed(state_);
}
return s;
}
Status TestWritableFile::Flush() {
Status s = target_->Flush();
if (s.ok() && env_->IsFilesystemActive()) {
state_.pos_at_last_flush_ = state_.pos_;
}
return s;
}
Status TestWritableFile::Sync() {
if (!env_->IsFilesystemActive()) {
return Status::IOError("FaultInjectionTestEnv: not active");
}
// No need to actual sync.
state_.pos_at_last_sync_ = state_.pos_;
env_->WritableFileSynced(state_);
return Status::OK();
}
Status FaultInjectionTestEnv::NewDirectory(const std::string& name,
std::unique_ptr<Directory>* result) {
std::unique_ptr<Directory> r;
Status s = target()->NewDirectory(name, &r);
assert(s.ok());
if (!s.ok()) {
return s;
}
result->reset(new TestDirectory(this, TrimDirname(name), r.release()));
return Status::OK();
}
Status FaultInjectionTestEnv::NewWritableFile(
const std::string& fname, std::unique_ptr<WritableFile>* result,
const EnvOptions& soptions) {
if (!IsFilesystemActive()) {
return GetError();
}
// Not allow overwriting files
Status s = target()->FileExists(fname);
if (s.ok()) {
return Status::Corruption("File already exists.");
} else if (!s.IsNotFound()) {
assert(s.IsIOError());
return s;
}
s = target()->NewWritableFile(fname, result, soptions);
if (s.ok()) {
result->reset(new TestWritableFile(fname, std::move(*result), this));
// WritableFileWriter* file is opened
// again then it will be truncated - so forget our saved state.
UntrackFile(fname);
MutexLock l(&mutex_);
open_files_.insert(fname);
auto dir_and_name = GetDirAndName(fname);
auto& list = dir_to_new_files_since_last_sync_[dir_and_name.first];
list.insert(dir_and_name.second);
}
return s;
}
Status FaultInjectionTestEnv::ReopenWritableFile(
const std::string& fname, std::unique_ptr<WritableFile>* result,
const EnvOptions& soptions) {
if (!IsFilesystemActive()) {
return GetError();
}
Status s = target()->ReopenWritableFile(fname, result, soptions);
if (s.ok()) {
result->reset(new TestWritableFile(fname, std::move(*result), this));
// WritableFileWriter* file is opened
// again then it will be truncated - so forget our saved state.
UntrackFile(fname);
MutexLock l(&mutex_);
open_files_.insert(fname);
auto dir_and_name = GetDirAndName(fname);
auto& list = dir_to_new_files_since_last_sync_[dir_and_name.first];
list.insert(dir_and_name.second);
}
return s;
}
Status FaultInjectionTestEnv::NewRandomAccessFile(
const std::string& fname, std::unique_ptr<RandomAccessFile>* result,
const EnvOptions& soptions) {
if (!IsFilesystemActive()) {
return GetError();
}
return target()->NewRandomAccessFile(fname, result, soptions);
}
Status FaultInjectionTestEnv::DeleteFile(const std::string& f) {
if (!IsFilesystemActive()) {
return GetError();
}
Status s = EnvWrapper::DeleteFile(f);
if (!s.ok()) {
fprintf(stderr, "Cannot delete file %s: %s\n", f.c_str(),
s.ToString().c_str());
}
assert(s.ok());
if (s.ok()) {
UntrackFile(f);
}
return s;
}
Status FaultInjectionTestEnv::RenameFile(const std::string& s,
const std::string& t) {
if (!IsFilesystemActive()) {
return GetError();
}
Status ret = EnvWrapper::RenameFile(s, t);
if (ret.ok()) {
MutexLock l(&mutex_);
if (db_file_state_.find(s) != db_file_state_.end()) {
db_file_state_[t] = db_file_state_[s];
db_file_state_.erase(s);
}
auto sdn = GetDirAndName(s);
auto tdn = GetDirAndName(t);
if (dir_to_new_files_since_last_sync_[sdn.first].erase(sdn.second) != 0) {
auto& tlist = dir_to_new_files_since_last_sync_[tdn.first];
assert(tlist.find(tdn.second) == tlist.end());
tlist.insert(tdn.second);
}
}
return ret;
}
void FaultInjectionTestEnv::WritableFileClosed(const FileState& state) {
MutexLock l(&mutex_);
if (open_files_.find(state.filename_) != open_files_.end()) {
db_file_state_[state.filename_] = state;
open_files_.erase(state.filename_);
}
}
void FaultInjectionTestEnv::WritableFileSynced(const FileState& state) {
MutexLock l(&mutex_);
if (open_files_.find(state.filename_) != open_files_.end()) {
if (db_file_state_.find(state.filename_) == db_file_state_.end()) {
db_file_state_.insert(std::make_pair(state.filename_, state));
} else {
db_file_state_[state.filename_] = state;
}
}
}
void FaultInjectionTestEnv::WritableFileAppended(const FileState& state) {
MutexLock l(&mutex_);
if (open_files_.find(state.filename_) != open_files_.end()) {
if (db_file_state_.find(state.filename_) == db_file_state_.end()) {
db_file_state_.insert(std::make_pair(state.filename_, state));
} else {
db_file_state_[state.filename_] = state;
}
}
}
// For every file that is not fully synced, make a call to `func` with
// FileState of the file as the parameter.
Status FaultInjectionTestEnv::DropFileData(
std::function<Status(Env*, FileState)> func) {
Status s;
MutexLock l(&mutex_);
for (std::map<std::string, FileState>::const_iterator it =
db_file_state_.begin();
s.ok() && it != db_file_state_.end(); ++it) {
const FileState& state = it->second;
if (!state.IsFullySynced()) {
s = func(target(), state);
}
}
return s;
}
Status FaultInjectionTestEnv::DropUnsyncedFileData() {
return DropFileData([&](Env* env, const FileState& state) {
return state.DropUnsyncedData(env);
});
}
Status FaultInjectionTestEnv::DropRandomUnsyncedFileData(Random* rnd) {
return DropFileData([&](Env* env, const FileState& state) {
return state.DropRandomUnsyncedData(env, rnd);
});
}
Status FaultInjectionTestEnv::DeleteFilesCreatedAfterLastDirSync() {
// Because DeleteFile access this container make a copy to avoid deadlock
std::map<std::string, std::set<std::string>> map_copy;
{
MutexLock l(&mutex_);
map_copy.insert(dir_to_new_files_since_last_sync_.begin(),
dir_to_new_files_since_last_sync_.end());
}
for (auto& pair : map_copy) {
for (std::string name : pair.second) {
Status s = DeleteFile(pair.first + "/" + name);
if (!s.ok()) {
return s;
}
}
}
return Status::OK();
}
void FaultInjectionTestEnv::ResetState() {
MutexLock l(&mutex_);
db_file_state_.clear();
dir_to_new_files_since_last_sync_.clear();
SetFilesystemActiveNoLock(true);
}
void FaultInjectionTestEnv::UntrackFile(const std::string& f) {
MutexLock l(&mutex_);
auto dir_and_name = GetDirAndName(f);
dir_to_new_files_since_last_sync_[dir_and_name.first].erase(
dir_and_name.second);
db_file_state_.erase(f);
open_files_.erase(f);
}
} // namespace rocksdb