Fix DeleteScheduler::MarkAsTrash() handling existing trash

Summary:
DeleteScheduler::MarkAsTrash() don't handle existing .trash files correctly
This cause rocksdb to not being able to delete existing .trash files on restart
Closes facebook#3261

Differential Revision: D6548003

Pulled By: IslamAbdelRahman

fbshipit-source-id: c3800639412e587a690062c63076a5a08881e0e6

db/db_sst_test.cc

@@ -376,6 +376,30 @@ TEST_F(DBSSTTest, RateLimitedDelete) {
   rocksdb::SyncPoint::GetInstance()->DisableProcessing();
 }
 
+TEST_F(DBSSTTest, OpenDBWithExistingTrash) {
+  Options options = CurrentOptions();
+
+  options.sst_file_manager.reset(
+      NewSstFileManager(env_, nullptr, "", 1024 * 1024 /* 1 MB/sec */));
+  auto sfm = static_cast<SstFileManagerImpl*>(options.sst_file_manager.get());
+
+  Destroy(last_options_);
+
+  // Add some trash files to the db directory so the DB can clean them up
+  env_->CreateDirIfMissing(dbname_);
+  ASSERT_OK(WriteStringToFile(env_, "abc", dbname_ + "/" + "001.sst.trash"));
+  ASSERT_OK(WriteStringToFile(env_, "abc", dbname_ + "/" + "002.sst.trash"));
+  ASSERT_OK(WriteStringToFile(env_, "abc", dbname_ + "/" + "003.sst.trash"));
+
+  // Reopen the DB and verify that it deletes existing trash files
+  ASSERT_OK(TryReopen(options));
+  sfm->WaitForEmptyTrash();
+  ASSERT_NOK(env_->FileExists(dbname_ + "/" + "001.sst.trash"));
+  ASSERT_NOK(env_->FileExists(dbname_ + "/" + "002.sst.trash"));
+  ASSERT_NOK(env_->FileExists(dbname_ + "/" + "003.sst.trash"));
+}
+
+
 // Create a DB with 2 db_paths, and generate multiple files in the 2
 // db_paths using CompactRangeOptions, make sure that files that were
 // deleted from first db_path were deleted using DeleteScheduler and

util/delete_scheduler.cc

@@ -151,6 +151,7 @@ Status DeleteScheduler::MarkAsTrash(const std::string& file_path,
   Status s;
   if (DeleteScheduler::IsTrashFile(file_path)) {
     // This is already a trash file
+    *trash_file = file_path;
     return s;
   }