Fix orphaned files in SstFileManager (#13015)

Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/13015

`Close()`ing a database now releases tracked files in `SstFileManager`. Previously this space would be leaked until the database was later reopened.

Reviewed By: jowlyzhang

Differential Revision: D62590773

fbshipit-source-id: 5461bd253d974ac4967ad52fee92e2650f8a9a28

db/db_impl/db_impl.cc

@@ -530,6 +530,11 @@ Status DBImpl::MaybeReleaseTimestampedSnapshotsAndCheck() {
   return Status::OK();
 }
 
+void DBImpl::UntrackDataFiles() {
+  TrackOrUntrackFiles(/*existing_data_files=*/{},
+                      /*track=*/false);
+}
+
 Status DBImpl::CloseHelper() {
   // Guarantee that there is no background error recovery in progress before
   // continuing with the shutdown
@@ -669,6 +674,13 @@ Status DBImpl::CloseHelper() {
     delete txn_entry.second;
   }
 
+  // Return an unowned SstFileManager to a consistent state
+  if (immutable_db_options_.sst_file_manager && !own_sfm_) {
+    mutex_.Unlock();
+    UntrackDataFiles();
+    mutex_.Lock();
+  }
+
   // versions need to be destroyed before table_cache since it can hold
   // references to table_cache.
   {
@@ -6747,6 +6759,62 @@ void DBImpl::RecordSeqnoToTimeMapping(uint64_t populate_historical_seconds) {
   }
 }
 
+void DBImpl::TrackOrUntrackFiles(
+    const std::vector<std::string>& existing_data_files, bool track) {
+  auto sfm = static_cast_with_check<SstFileManagerImpl>(
+      immutable_db_options_.sst_file_manager.get());
+  assert(sfm);
+  std::vector<ColumnFamilyMetaData> metadata;
+  GetAllColumnFamilyMetaData(&metadata);
+  auto action = [&](const std::string& file_path,
+                    std::optional<uint64_t> size) {
+    if (track) {
+      if (size) {
+        sfm->OnAddFile(file_path, *size).PermitUncheckedError();
+      } else {
+        sfm->OnAddFile(file_path).PermitUncheckedError();
+      }
+    } else {
+      sfm->OnUntrackFile(file_path).PermitUncheckedError();
+    }
+  };
+
+  std::unordered_set<std::string> referenced_files;
+  for (const auto& md : metadata) {
+    for (const auto& lmd : md.levels) {
+      for (const auto& fmd : lmd.files) {
+        // We're assuming that each sst file name exists in at most one of
+        // the paths.
+        std::string file_path =
+            fmd.directory + kFilePathSeparator + fmd.relative_filename;
+        action(file_path, fmd.size);
+        referenced_files.insert(file_path);
+      }
+    }
+    for (const auto& bmd : md.blob_files) {
+      std::string name = bmd.blob_file_name;
+      // The BlobMetaData.blob_file_name may start with "/".
+      if (!name.empty() && name[0] == kFilePathSeparator) {
+        name = name.substr(1);
+      }
+      // We're assuming that each blob file name exists in at most one of
+      // the paths.
+      std::string file_path = bmd.blob_file_path + kFilePathSeparator + name;
+      action(file_path, bmd.blob_file_size);
+      referenced_files.insert(file_path);
+    }
+  }
+
+  for (const auto& file_path : existing_data_files) {
+    if (referenced_files.find(file_path) != referenced_files.end()) {
+      continue;
+    }
+    // There shouldn't be any duplicated files. In case there is, SstFileManager
+    // will take care of deduping it.
+    action(file_path, /*size=*/std::nullopt);
+  }
+}
+
 void DBImpl::InstallSeqnoToTimeMappingInSV(
     std::vector<SuperVersionContext>* sv_contexts) {
   mutex_.AssertHeld();

db/db_impl/db_impl.h

@@ -1618,9 +1618,15 @@ class DBImpl : public DB {
   // vast majority of all files), since it already has the file size
   // on record, we don't need to query the file system. Otherwise, we query the
   // file system for the size of an unreferenced file.
+  // REQUIRES: mutex unlocked
   void TrackExistingDataFiles(
       const std::vector<std::string>& existing_data_files);
 
+  // Untrack data files in sst manager. This is only called during DB::Close on
+  // an unowned SstFileManager, to return it to a consistent state.
+  // REQUIRES: mutex unlocked
+  void UntrackDataFiles();
+
   // SetDbSessionId() should be called in the constuctor DBImpl()
   // to ensure that db_session_id_ gets updated every time the DB is opened
   void SetDbSessionId();
@@ -2190,6 +2196,10 @@ class DBImpl : public DB {
                           JobContext* job_context, LogBuffer* log_buffer,
                           CompactionJobInfo* compaction_job_info);
 
+  // REQUIRES: mutex unlocked
+  void TrackOrUntrackFiles(const std::vector<std::string>& existing_data_files,
+                           bool track);
+
   ColumnFamilyData* GetColumnFamilyDataByName(const std::string& cf_name);
 
   void MaybeScheduleFlushOrCompaction();

db/db_impl/db_impl_open.cc

@@ -1988,46 +1988,7 @@ IOStatus DBImpl::CreateWAL(const WriteOptions& write_options,
 
 void DBImpl::TrackExistingDataFiles(
     const std::vector<std::string>& existing_data_files) {
-  auto sfm = static_cast<SstFileManagerImpl*>(
-      immutable_db_options_.sst_file_manager.get());
-  assert(sfm);
-  std::vector<ColumnFamilyMetaData> metadata;
-  GetAllColumnFamilyMetaData(&metadata);
-
-  std::unordered_set<std::string> referenced_files;
-  for (const auto& md : metadata) {
-    for (const auto& lmd : md.levels) {
-      for (const auto& fmd : lmd.files) {
-        // We're assuming that each sst file name exists in at most one of
-        // the paths.
-        std::string file_path =
-            fmd.directory + kFilePathSeparator + fmd.relative_filename;
-        sfm->OnAddFile(file_path, fmd.size).PermitUncheckedError();
-        referenced_files.insert(file_path);
-      }
-    }
-    for (const auto& bmd : md.blob_files) {
-      std::string name = bmd.blob_file_name;
-      // The BlobMetaData.blob_file_name may start with "/".
-      if (!name.empty() && name[0] == kFilePathSeparator) {
-        name = name.substr(1);
-      }
-      // We're assuming that each blob file name exists in at most one of
-      // the paths.
-      std::string file_path = bmd.blob_file_path + kFilePathSeparator + name;
-      sfm->OnAddFile(file_path, bmd.blob_file_size).PermitUncheckedError();
-      referenced_files.insert(file_path);
-    }
-  }
-
-  for (const auto& file_path : existing_data_files) {
-    if (referenced_files.find(file_path) != referenced_files.end()) {
-      continue;
-    }
-    // There shouldn't be any duplicated files. In case there is, SstFileManager
-    // will take care of deduping it.
-    sfm->OnAddFile(file_path).PermitUncheckedError();
-  }
+  TrackOrUntrackFiles(existing_data_files, /*track=*/true);
 }
 
 Status DBImpl::Open(const DBOptions& db_options, const std::string& dbname,

db/db_sst_test.cc

@@ -383,12 +383,16 @@ TEST_F(DBSSTTest, DBWithSstFileManager) {
   ASSERT_EQ(files_moved, 0);
 
   Close();
+  ASSERT_EQ(sfm->GetTrackedFiles().size(), 0) << "sfm should be empty";
+  ASSERT_EQ(sfm->GetTotalSize(), 0) << "sfm should be empty";
   Reopen(options);
   ASSERT_EQ(sfm->GetTrackedFiles(), files_in_db);
   ASSERT_EQ(sfm->GetTotalSize(), total_files_size);
 
   // Verify that we track all the files again after the DB is closed and opened
   Close();
+  ASSERT_EQ(sfm->GetTrackedFiles().size(), 0) << "sfm should be empty";
+  ASSERT_EQ(sfm->GetTotalSize(), 0) << "sfm should be empty";
   sst_file_manager.reset(NewSstFileManager(env_));
   options.sst_file_manager = sst_file_manager;
   sfm = static_cast<SstFileManagerImpl*>(sst_file_manager.get());
@@ -439,6 +443,11 @@ TEST_F(DBSSTTest, DBWithSstFileManagerForBlobFiles) {
 
   ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
       "SstFileManagerImpl::OnMoveFile", [&](void* /*arg*/) { files_moved++; });
+
+  int64_t untracked_files = 0;
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "SstFileManagerImpl::OnUntrackFile",
+      [&](void* /*arg*/) { ++untracked_files; });
   ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
 
   Options options = CurrentOptions();
@@ -485,6 +494,10 @@ TEST_F(DBSSTTest, DBWithSstFileManagerForBlobFiles) {
   }
   ASSERT_EQ(sfm->GetTotalSize(), total_files_size);
   Close();
+  ASSERT_EQ(untracked_files, files_in_db.size());
+  untracked_files = 0;
+  ASSERT_EQ(sfm->GetTrackedFiles().size(), 0) << "sfm should be empty";
+  ASSERT_EQ(sfm->GetTotalSize(), 0) << "sfm should be empty";
 
   Reopen(options);
   ASSERT_EQ(sfm->GetTrackedFiles(), files_in_db);
@@ -492,6 +505,10 @@ TEST_F(DBSSTTest, DBWithSstFileManagerForBlobFiles) {
 
   // Verify that we track all the files again after the DB is closed and opened.
   Close();
+  ASSERT_EQ(untracked_files, files_in_db.size());
+  untracked_files = 0;
+  ASSERT_EQ(sfm->GetTrackedFiles().size(), 0) << "sfm should be empty";
+  ASSERT_EQ(sfm->GetTotalSize(), 0) << "sfm should be empty";
 
   sst_file_manager.reset(NewSstFileManager(env_));
   options.sst_file_manager = sst_file_manager;
@@ -507,6 +524,10 @@ TEST_F(DBSSTTest, DBWithSstFileManagerForBlobFiles) {
   ASSERT_EQ(files_deleted, 0);
   ASSERT_EQ(files_scheduled_to_delete, 0);
   Close();
+  ASSERT_EQ(untracked_files, files_in_db.size());
+  untracked_files = 0;
+  ASSERT_EQ(sfm->GetTrackedFiles().size(), 0) << "sfm should be empty";
+  ASSERT_EQ(sfm->GetTotalSize(), 0) << "sfm should be empty";
   ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
       "SstFileManagerImpl::ScheduleUnaccountedFileDeletion", [&](void* arg) {
         assert(arg);
@@ -666,6 +687,9 @@ TEST_F(DBSSTTest, DBWithSstFileManagerForBlobFilesWithGC) {
   }
 
   Close();
+  ASSERT_EQ(sfm->GetTrackedFiles().size(), 0) << "sfm should be empty";
+  ASSERT_EQ(sfm->GetTotalSize(), 0) << "sfm should be empty";
+
   ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
       "SstFileManagerImpl::ScheduleUnaccountedFileDeletion", [&](void* arg) {
         assert(arg);

file/sst_file_manager_impl.cc

@@ -118,6 +118,16 @@ Status SstFileManagerImpl::OnMoveFile(const std::string& old_path,
   return Status::OK();
 }
 
+Status SstFileManagerImpl::OnUntrackFile(const std::string& file_path) {
+  {
+    MutexLock l(&mu_);
+    OnDeleteFileImpl(file_path);
+  }
+  TEST_SYNC_POINT_CALLBACK("SstFileManagerImpl::OnUntrackFile",
+                           const_cast<std::string*>(&file_path));
+  return Status::OK();
+}
+
 void SstFileManagerImpl::SetMaxAllowedSpaceUsage(uint64_t max_allowed_space) {
   MutexLock l(&mu_);
   max_allowed_space_ = max_allowed_space;

file/sst_file_manager_impl.h

@@ -50,6 +50,9 @@ class SstFileManagerImpl : public SstFileManager {
   Status OnMoveFile(const std::string& old_path, const std::string& new_path,
                     uint64_t* file_size = nullptr);
 
+  // DB will call OnUntrackFile when closing with an unowned SstFileManager.
+  Status OnUntrackFile(const std::string& file_path);
+
   // Update the maximum allowed space that should be used by RocksDB, if
   // the total size of the SST and blob files exceeds max_allowed_space, writes
   // to RocksDB will fail.
@@ -217,4 +220,3 @@ class SstFileManagerImpl : public SstFileManager {
 };
 
 }  // namespace ROCKSDB_NAMESPACE
-

unreleased_history/behavior_changes/sst_file_manager_untrack_close.md

@@ -0,0 +1,2 @@
+DB::Close now untracks files in SstFileManager, making avaialble any space used
+by them. Prior to this change they would be orphaned until the DB is re-opened.