Near-Catastrophic OpenZFS Bug Highlights the Power of Rust's Type System

A subtle yet devastating bug in OpenZFS's core disk allocation function was recently discovered. The bug, a simple type error resulting in the wrong size being returned, could silently overwrite data. It took nearly two days to track down. While the bug wasn't present in any released version, it spurred reflection on the limitations of static analysis in C and the advantages of Rust's type system. Rust's ability to define custom types (like `PhysicalSize` and `AllocatedSize`) would have prevented this. The author argues that relying solely on programmer perfection is flawed; leveraging tools and language features to improve code quality and mitigate hard-to-detect, high-impact bugs is key.