[$] The “rnull” Rust block driver

Post Syndicated from daroc original https://lwn.net/Articles/1090378/

The
null block
driver
(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
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.