[PATCH v4 0/2] rust/revocable: add try_access_with() convenience method

From: Alexandre Courbot
Date: Fri Apr 11 2025 - 08:11:09 EST


This is a feature I found useful to have while writing Nova driver code
that accessed registers alongside other operations. I would find myself
quite confused about whether the guard was held or dropped at a given
point of the code, and it felt like walking through a minefield; this
pattern makes things safer and easier to read according to my experience
writing nova-core code.

Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxx>
---
Changes in v4:
- Collected Reviewed-by tags.
- Link to v3: https://lore.kernel.org/r/20250406-try_with-v3-0-c0947842e768@xxxxxxxxxx

Changes in v3:
- Add Acked-by from v2.

Changes in v2:
- Use FnOnce for the callback type.
- Rename to try_access_with.
- Don't assume that users will want to map failure to ENXIO and return
an option.
- Use a single method and let users adapt the behavior using their own
wrappers/macros.

---
Alexandre Courbot (2):
rust/revocable: add try_access_with() convenience method
samples: rust: convert PCI rust sample driver to use try_access_with()

rust/kernel/revocable.rs | 16 ++++++++++++++++
samples/rust/rust_driver_pci.rs | 11 +++++------
2 files changed, 21 insertions(+), 6 deletions(-)
---
base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8
change-id: 20250313-try_with-cc9f91dd3b60

Best regards,
--
Alexandre Courbot <acourbot@xxxxxxxxxx>