Add missing synchronization in TestFSWritableFile (#10544)

Summary:
**Context:**
ajkr's command revealed an existing TSAN data race between `TestFSWritableFile::Append` and `TestFSWritableFile::Sync` on `TestFSWritableFile::state_`

```
$ make clean && COMPILE_WITH_TSAN=1 make -j56 db_stress
$ python3 tools/db_crashtest.py blackbox --simple --duration=3600 --interval=10 --sync_fault_injection=1 --disable_wal=0 --max_key=10000 --checkpoint_one_in=1000
```

The race is due to concurrent access from [checkpoint's WAL sync](https://github.com/facebook/rocksdb/blob/7.4.fb/utilities/fault_injection_fs.cc#L324) and [db put's WAL write when ‘sync_fault_injection=1 ‘](https://github.com/facebook/rocksdb/blob/7.4.fb/utilities/fault_injection_fs.cc#L208) to the `state_` on the same WAL `TestFSWritableFile` under the missing synchronization.

```
WARNING: ThreadSanitizer: data race (pid=11275)
Write of size 8 at 0x7b480003d850 by thread T23 (mutexes: write M69230):
#0 rocksdb::TestFSWritableFile::Sync(rocksdb::IOOptions const&, rocksdb::IODebugContext*) internal_repo_rocksdb/repo/utilities/fault_injection_fs.cc:297 (db_stress+0x716004)
#1 rocksdb::(anonymous namespace)::CompositeWritableFileWrapper::Sync() internal_repo_rocksdb/repo/env/composite_env.cc:154 (db_stress+0x4dfa78)
#2 rocksdb::(anonymous namespace)::LegacyWritableFileWrapper::Sync(rocksdb::IOOptions const&, rocksdb::IODebugContext*) internal_repo_rocksdb/repo/env/env.cc:280 (db_stress+0x6dfd24)
#3 rocksdb::WritableFileWriter::SyncInternal(bool) internal_repo_rocksdb/repo/file/writable_file_writer.cc:460 (db_stress+0xa1b98c)
#4 rocksdb::WritableFileWriter::SyncWithoutFlush(bool) internal_repo_rocksdb/repo/file/writable_file_writer.cc:435 (db_stress+0xa1e441)
#5 rocksdb::DBImpl::SyncWAL() internal_repo_rocksdb/repo/db/db_impl/db_impl.cc:1385 (db_stress+0x529458)
#6 rocksdb::DBImpl::FlushWAL(bool) internal_repo_rocksdb/repo/db/db_impl/db_impl.cc:1339 (db_stress+0x54f82a)
#7 rocksdb::DBImpl::GetLiveFilesStorageInfo(rocksdb::LiveFilesStorageInfoOptions const&, std::vector<rocksdb::LiveFileStorageInfo, std::allocator<rocksdb::LiveFileStorageInfo> >*) internal_repo_rocksdb/repo/db/db_filesnapshot.cc:387 (db_stress+0x5c831d)
#8 rocksdb::CheckpointImpl::CreateCustomCheckpoint(std::function<rocksdb::Status (std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, rocksdb::FileType)>, std::function<rocksdb::Status (std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, unsigned long, rocksdb::FileType, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, rocksdb::Temperature)>, std::function<rocksdb::Status (std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, rocksdb::FileType)>, unsigned long*, unsigned long, bool) internal_repo_rocksdb/repo/utilities/checkpoint/checkpoint_impl.cc:214 (db_stress+0x4c0343)
#9 rocksdb::CheckpointImpl::CreateCheckpoint(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, unsigned long, unsigned long*) internal_repo_rocksdb/repo/utilities/checkpoint/checkpoint_impl.cc:123 (db_stress+0x4c237e)
#10 rocksdb::StressTest::TestCheckpoint(rocksdb::ThreadState*, std::vector<int, std::allocator<int> > const&, std::vector<long, std::allocator<long> > const&) internal_repo_rocksdb/repo/db_stress_tool/db_stress_test_base.cc:1699 (db_stress+0x328340)
#11 rocksdb::StressTest::OperateDb(rocksdb::ThreadState*) internal_repo_rocksdb/repo/db_stress_tool/db_stress_test_base.cc:825 (db_stress+0x33921f)
#12 rocksdb::ThreadBody(void*) internal_repo_rocksdb/repo/db_stress_tool/db_stress_driver.cc:33 (db_stress+0x354857)
#13 rocksdb::(anonymous namespace)::StartThreadWrapper(void*) internal_repo_rocksdb/repo/env/env_posix.cc:447 (db_stress+0x6eb2ad)

Previous read of size 8 at 0x7b480003d850 by thread T64 (mutexes: write M980798978697532600, write M253744503184415024, write M1262):
#0 memcpy <null> (db_stress+0xbc9696)
#1 operator= internal_repo_rocksdb/repo/utilities/fault_injection_fs.h:35 (db_stress+0x70d5f1)
#2 rocksdb::FaultInjectionTestFS::WritableFileAppended(rocksdb::FSFileState const&) internal_repo_rocksdb/repo/utilities/fault_injection_fs.cc:827 (db_stress+0x70d5f1)
#3 rocksdb::TestFSWritableFile::Append(rocksdb::Slice const&, rocksdb::IOOptions const&, rocksdb::IODebugContext*) internal_repo_rocksdb/repo/utilities/fault_injection_fs.cc:173 (db_stress+0x7143af)
#4 rocksdb::(anonymous namespace)::CompositeWritableFileWrapper::Append(rocksdb::Slice const&) internal_repo_rocksdb/repo/env/composite_env.cc:115 (db_stress+0x4de3ab)
#5 rocksdb::(anonymous namespace)::LegacyWritableFileWrapper::Append(rocksdb::Slice const&, rocksdb::IOOptions const&, rocksdb::IODebugContext*) internal_repo_rocksdb/repo/env/env.cc:248 (db_stress+0x6df44b)
#6 rocksdb::WritableFileWriter::WriteBuffered(char const*, unsigned long, rocksdb::Env::IOPriority) internal_repo_rocksdb/repo/file/writable_file_writer.cc:551 (db_stress+0xa1a953)
#7 rocksdb::WritableFileWriter::Flush(rocksdb::Env::IOPriority) internal_repo_rocksdb/repo/file/writable_file_writer.cc:327 (db_stress+0xa16ee8)
#8 rocksdb::log::Writer::AddRecord(rocksdb::Slice const&, rocksdb::Env::IOPriority) internal_repo_rocksdb/repo/db/log_writer.cc:147 (db_stress+0x7f121f)
#9 rocksdb::DBImpl::WriteToWAL(rocksdb::WriteBatch const&, rocksdb::log::Writer*, unsigned long*, unsigned long*, rocksdb::Env::IOPriority, rocksdb::DBImpl::LogFileNumberSize&) internal_repo_rocksdb/repo/db/db_impl/db_impl_write.cc:1285 (db_stress+0x695042)
#10 rocksdb::DBImpl::WriteToWAL(rocksdb::WriteThread::WriteGroup const&, rocksdb::log::Writer*, unsigned long*, bool, bool, unsigned long, rocksdb::DBImpl::LogFileNumberSize&) internal_repo_rocksdb/repo/db/db_impl/db_impl_write.cc:1328 (db_stress+0x6907e8)
#11 rocksdb::DBImpl::PipelinedWriteImpl(rocksdb::WriteOptions const&, rocksdb::WriteBatch*, rocksdb::WriteCallback*, unsigned long*, unsigned long, bool, unsigned long*) internal_repo_rocksdb/repo/db/db_impl/db_impl_write.cc:731 (db_stress+0x68e8a7)
#12 rocksdb::DBImpl::WriteImpl(rocksdb::WriteOptions const&, rocksdb::WriteBatch*, rocksdb::WriteCallback*, unsigned long*, unsigned long, bool, unsigned long*, unsigned long, rocksdb::PreReleaseCallback*, rocksdb::PostMemTableCallback*) internal_repo_rocksdb/repo/db/db_impl/db_impl_write.cc:283 (db_stress+0x688370)
#13 rocksdb::DBImpl::Write(rocksdb::WriteOptions const&, rocksdb::WriteBatch*) internal_repo_rocksdb/repo/db/db_impl/db_impl_write.cc:126 (db_stress+0x69a7b5)
#14 rocksdb::DB::Put(rocksdb::WriteOptions const&, rocksdb::ColumnFamilyHandle*, rocksdb::Slice const&, rocksdb::Slice const&, rocksdb::Slice const&) internal_repo_rocksdb/repo/db/db_impl/db_impl_write.cc:2247 (db_stress+0x698634)
#15 rocksdb::DBImpl::Put(rocksdb::WriteOptions const&, rocksdb::ColumnFamilyHandle*, rocksdb::Slice const&, rocksdb::Slice const&, rocksdb::Slice const&) internal_repo_rocksdb/repo/db/db_impl/db_impl_write.cc:37 (db_stress+0x699868)
#16 rocksdb::NonBatchedOpsStressTest::TestPut(rocksdb::ThreadState*, rocksdb::WriteOptions&, rocksdb::ReadOptions const&, std::vector<int, std::allocator<int> > const&, std::vector<long, std::allocator<long> > const&, char (&) [100], std::unique_ptr<rocksdb::MutexLock, std::default_delete<rocksdb::MutexLock> >&) internal_repo_rocksdb/repo/db_stress_tool/no_batched_ops_stress.cc:681 (db_stress+0x38d20c)
#17 rocksdb::StressTest::OperateDb(rocksdb::ThreadState*) internal_repo_rocksdb/repo/db_stress_tool/db_stress_test_base.cc:897 (db_stress+0x3399ec)
#18 rocksdb::ThreadBody(void*) internal_repo_rocksdb/repo/db_stress_tool/db_stress_driver.cc:33 (db_stress+0x354857)
#19 rocksdb::(anonymous namespace)::StartThreadWrapper(void*) internal_repo_rocksdb/repo/env/env_posix.cc:447 (db_stress+0x6eb2ad)

Location is heap block of size 352 at 0x7b480003d800 allocated by thread T23:
#0 operator new(unsigned long) <null> (db_stress+0xb685dc)
#1 rocksdb::FaultInjectionTestFS::NewWritableFile(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, rocksdb::FileOptions const&, std::unique_ptr<rocksdb::FSWritableFile, std::default_delete<rocksdb::FSWritableFile> >*, rocksdb::IODebugContext*) internal_repo_rocksdb/repo/utilities/fault_injection_fs.cc:506 (db_stress+0x711192)
#2 rocksdb::CompositeEnv::NewWritableFile(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unique_ptr<rocksdb::WritableFile, std::default_delete<rocksdb::WritableFile> >*, rocksdb::EnvOptions const&) internal_repo_rocksdb/repo/env/composite_env.cc:329 (db_stress+0x4d33fa)
#3 rocksdb::EnvWrapper::NewWritableFile(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unique_ptr<rocksdb::WritableFile, std::default_delete<rocksdb::WritableFile> >*, rocksdb::EnvOptions const&) internal_repo_rocksdb/repo/include/rocksdb/env.h:1425 (db_stress+0x300662)
...
```

**Summary:**
- Added the missing lock in functions mentioned above along with three other functions with a similar need in TestFSWritableFile
- Added clarification comment

Pull Request resolved: #10544

Test Plan: - Past the above race condition repro

Reviewed By: ajkr

Differential Revision: D38886634

Pulled By: hx235

fbshipit-source-id: 0571bae9615f35b16fbd8168204607e306b1b486

utilities/fault_injection_fs.cc

@@ -240,6 +240,7 @@ IOStatus TestFSWritableFile::PositionedAppend(
 
 IOStatus TestFSWritableFile::Close(const IOOptions& options,
                                    IODebugContext* dbg) {
+  MutexLock l(&mutex_);
   if (!fs_->IsFilesystemActive()) {
     return fs_->GetError();
   }
@@ -271,6 +272,7 @@ IOStatus TestFSWritableFile::Close(const IOOptions& options,
 }
 
 IOStatus TestFSWritableFile::Flush(const IOOptions&, IODebugContext*) {
+  MutexLock l(&mutex_);
   if (!fs_->IsFilesystemActive()) {
     return fs_->GetError();
   }
@@ -282,6 +284,7 @@ IOStatus TestFSWritableFile::Flush(const IOOptions&, IODebugContext*) {
 
 IOStatus TestFSWritableFile::Sync(const IOOptions& options,
                                   IODebugContext* dbg) {
+  MutexLock l(&mutex_);
   if (!fs_->IsFilesystemActive()) {
     return fs_->GetError();
   }
@@ -302,6 +305,7 @@ IOStatus TestFSWritableFile::Sync(const IOOptions& options,
 IOStatus TestFSWritableFile::RangeSync(uint64_t offset, uint64_t nbytes,
                                        const IOOptions& options,
                                        IODebugContext* dbg) {
+  MutexLock l(&mutex_);
   if (!fs_->IsFilesystemActive()) {
     return fs_->GetError();
   }

utilities/fault_injection_fs.h

@@ -97,7 +97,7 @@ class TestFSWritableFile : public FSWritableFile {
   };
 
  private:
-  FSFileState state_;
+  FSFileState state_;  // Need protection by mutex_
   FileOptions file_opts_;
   std::unique_ptr<FSWritableFile> target_;
   bool writable_file_opened_;