o/blockdev: add options support

Allow passing options to Open(). This resolves a TODO left from when
blockdev was initially implemented and is now needed as Linux 6.12
rejects opening mounted block devices read-write, so we needed at least
a read-only option.

I also implemented the two options mentioned in the now-removed TODO
even though we're not using them yet.

These options are implemented generically to facilitate their use in
cross-platform code. Unsupported options are rejected at runtime. This
is similar to how Go's own stdlib does this.

Change-Id: I2548cb31e59a5c1198ca04537450bdf665878ca8
Reviewed-on: https://review.monogon.dev/c/monogon/+/3985
Reviewed-by: Jan Schär <jan@monogon.tech>
Tested-by: Jenkins CI
4 files changed
tree: 1d41385e553b8ab7b60e3dad8fc0bcfc8ab5cf29
  1. .github/
  2. .vscode/
  3. build/
  4. cloud/
  5. go/
  6. intellij/
  7. metropolis/
  8. osbase/
  9. third_party/
  10. tools/
  11. version/
  12. .bazelignore
  13. .bazelproject
  14. .bazelrc
  15. .bazelrc.ci
  16. .bazelrc.sandboxroot
  17. .bazelversion
  18. .git-ignore-revs
  19. .gitignore
  20. BUILD.bazel
  21. CODING_STANDARDS.md
  22. go.mod
  23. go.sum
  24. LICENSE
  25. MODULE.bazel
  26. MODULE.bazel.lock
  27. README.md
  28. SETUP.md
  29. shell.nix
  30. WORKSPACE
README.md

Monogon Monorepo

This is the main repository containing the source code for the Monogon Platform.

This is pre-release software - take a look, and check back later! In the meantime, join us on Matrix (#monogon-os-community:matrix.org) or Discord.

Environment

Our build environment is self-contained and requires only minimal host dependencies:

  • A Linux machine or VM.
  • Bazelisk >= v1.15.0 (or a working Nix environment).
  • A reasonably recent kernel with user namespaces enabled.
  • Working KVM with access to /dev/kvm (if you want to run tests).

Our docs assume that Bazelisk is available as bazel on your PATH.

Refer to SETUP.md for detailed instructions.

Monogon OS

The source code lives in //metropolis (Metropolis is the codename of Monogon OS).

See the //metropolis/README.md for a developer quick start guide, or see the Monogon OS Handbook for user documentation.