Relax synchronization mode in sqlite3.

src/libutil/sqlite_utils.c

@@ -248,7 +248,8 @@ rspamd_sqlite3_open_or_create (rspamd_mempool_t *pool, const gchar *path, const
 	gint rc, flags, lock_fd;
 	gchar lock_path[PATH_MAX], dbdir[PATH_MAX], *pdir;
 	static const char sqlite_wal[] = "PRAGMA journal_mode=\"wal\";",
-			exclusive_lock_sql[] = "PRAGMA locking_mode=\"exclusive\";";
+			exclusive_lock_sql[] = "PRAGMA locking_mode=\"exclusive\";",
+			fsync_sql[] = "PRAGMA database.synchronous=1;";
 	gboolean create = FALSE, has_lock = FALSE;
 
 	flags = SQLITE_OPEN_READWRITE;
@@ -371,6 +372,11 @@ rspamd_sqlite3_open_or_create (rspamd_mempool_t *pool, const gchar *path, const
 				sqlite3_errmsg (sqlite));
 	}
 
+	if (sqlite3_exec (sqlite, fsync_sql, NULL, NULL, NULL) != SQLITE_OK) {
+		msg_warn_pool ("cannot set database.synchronous: %s",
+				sqlite3_errmsg (sqlite));
+	}
+
 	if (has_lock) {
 		msg_debug_pool ("removing lock from %s", lock_path);
 		rspamd_file_unlock (lock_fd, FALSE);