Yes, I'm more disappointed that this wasn't picked up by an automated test suite than the fact that it might take a few days to patch.
Surely someone, somewhere is at least creating daily snapshots of the code and putting it through fuzzers and stress-tests and simulated disk-full situations? If not, why not? This is filesystem code we're talking about, not the backend of some casual game.
The code is all well and good but testing should be taking up far more CPU-time globally than all the compilation and coding on it across the world put together.