Savestates/sys_fs: Fix file saving

rpcs3/Emu/Cell/lv2/sys_fs.cpp

@@ -502,20 +502,28 @@ void lv2_file::save(utils::serial& ar)
 		fs::file_id test_s = test.get_id();
 		fs::file_id file_s = file.get_id();
 
-		return test_s.is_coherent_with(file_s);
+		return !test_s.is_coherent_with(file_s);
 	}();
 
-	if (in_mem)
-	{
-		sys_fs.error("Saving \'%s\' LV2 file descriptor in memory! (exists=%s, type=%s, flags=0x%x)", name.data(), fs::is_file(real_path), type, flags);
-	}
-
 	ar(in_mem);
 
 	if (in_mem)
 	{
-		ar(file.to_vector<u8>());
-		ar(file.get_stat());
+		fs::stat_t stats = file.get_stat();
+
+		sys_fs.error("Saving \'%s\' LV2 file descriptor in memory! (exists=%s, type=%s, flags=0x%x, size=0x%x)", name.data(), fs::is_file(real_path), type, flags, stats.size);
+
+		const usz old_end = ar.pad_from_end(stats.size);
+
+		if (usz read_size = file.read_at(0, &ar.data[old_end], stats.size); read_size != stats.size)
+		{
+			ensure(read_size < stats.size);
+			sys_fs.error("Read less than expected! (new-size=0x%x)", read_size);
+			stats.size = read_size;
+			ar.data.resize(old_end + stats.size);
+		}
+
+		ar(stats);
 	}
 
 	ar(file.pos());

rpcs3/util/serialization.hpp

@@ -324,6 +324,14 @@ namespace utils
 			return pos;
 		}
 
+		usz pad_from_end(usz forwards)
+		{
+			ensure(is_writing());
+			pos = data.size();
+			data.resize(pos + forwards);
+			return pos;
+		}
+
 		template <typename T> requires (std::is_copy_constructible_v<std::remove_const_t<T>>) && (std::is_constructible_v<std::remove_const_t<T>> || Bitcopy<std::remove_const_t<T>> ||
 			std::is_constructible_v<std::remove_const_t<T>, stx::exact_t<serial&>> || TupleAlike<std::remove_const_t<T>>)
 		operator T()