# [$] The "rnull" Rust block driver > Source: > Published: 2026-08-28 18:26:23+00:00 The [null block driver](https://www.kernel.org/doc/html/latest/block/null_blk.html) (`null_blk`) is a small driver that is mostly useful for benchmarking block-layer implementations. It accepts all requests and marks them complete as quickly as possible, doing as little work as possible. In June 2026, Andreas Hindborg shared [ a patch set](https://lwn.net/ml/all/20260609-rnull-v6-19-rc5-send-v2-0-82c7404542e2@kernel.org/) implementing the same functionality in Rust, in order to show that a simple block driver is now possible to write using the kernel's Rust APIs and to enable comparisons between the C and Rust implementations. A minimal version of the "rnull" driver is already present in the mainline kernel, but Hindborg's patch set brings it up to feature parity with the C version.