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Date: Sat, 1 Jun 2024 08:24:29 -0600
From: Keith Busch <kbusch@kernel.org>
To: Andreas Hindborg <nmi@metaspace.dk>
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Subject: Re: [PATCH v4 2/3] rust: block: add rnull, Rust null_blk
 implementation
Message-ID: <ZlsvHV6y4DEdC8ja@kbusch-mbp.dhcp.thefacebook.com>
References: <20240601134005.621714-1-nmi@metaspace.dk>
 <20240601134005.621714-3-nmi@metaspace.dk>
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On Sat, Jun 01, 2024 at 03:40:04PM +0200, Andreas Hindborg wrote:
> +impl kernel::Module for NullBlkModule {
> +    fn init(_module: &'static ThisModule) -> Result<Self> {
> +        pr_info!("Rust null_blk loaded\n");
> +        let tagset = Arc::pin_init(TagSet::try_new(1, 256, 1), flags::GFP_KERNEL)?;
> +
> +        let disk = {
> +            let block_size: u16 = 4096;
> +            if block_size % 512 != 0 || !(512..=4096).contains(&block_size) {
> +                return Err(kernel::error::code::EINVAL);
> +            }

You've set block_size to the literal 4096, then validate its value
immediately after? Am I missing some way this could ever be invalid?