Re: [PATCH v3 10/16] rust: block: add block related constants

[Daniel Almeida <daniel.almeida@collabora.com>]

> On 11 Jul 2025, at 08:43, Andreas Hindborg <a.hindborg@kernel.org> wrote:
> 
> Add a few block subsystem constants to the rust `kernel::block` name space.
> This makes it easier to access the constants from rust code.
> 
> Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
> ---
> rust/kernel/block.rs | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
> 
> diff --git a/rust/kernel/block.rs b/rust/kernel/block.rs
> index 150f710efe5b..7461adf4d7e0 100644
> --- a/rust/kernel/block.rs
> +++ b/rust/kernel/block.rs
> @@ -3,3 +3,15 @@
> //! Types for working with the block layer.
> 
> pub mod mq;
> +
> +/// Bit mask for masking out [`SECTOR_SIZE`]

Missing period.

> +pub const SECTOR_MASK: u32 = bindings::SECTOR_MASK;
> +
> +/// Sectors are size `1 << SECTOR_SHIFT`.
> +pub const SECTOR_SHIFT: u32 = bindings::SECTOR_SHIFT;
> +
> +/// Size of a sector.
> +pub const SECTOR_SIZE: u32 = bindings::SECTOR_SIZE;
> +
> +/// Power of two difference in size of a page and size of a sector.

A bit hard to parse this.

Maybe “The difference between the size of a page and the size of a sector,
expressed as a power of two” ?

> +pub const PAGE_SECTORS_SHIFT: u32 = bindings::PAGE_SECTORS_SHIFT;
> 
> -- 
> 2.47.2
> 
> 
> 


 let sector: usize = something;
 let page_offset = (sector & block::SECTOR_MASK as usize) << block::SECTOR_SHIFT;


Wait, the parenthesis evaluate to usize, and the shift is a u32. How does this compile?

— Daniel