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Howlett" , linux-block@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Content-Type: text/plain; charset="utf-8" On Mon, Feb 16, 2026 at 12:35:07AM +0100, Andreas Hindborg wrote: > +configfs_attribute!(DeviceConfig, 10, > + show: |this, page| show_field(this.data.lock().discard, page), > + store: |this, page| store_with_power_check(this, page, |this, page| { > + if !this.data.lock().memory_backed { > + return Err(EINVAL); > + } > + this.data.lock().discard = kstrtobool_bytes(page)?; Similar to the race I mentioned earlier with store_with_power_check(), this is also a TOCTOU race. > + discard: u8 { > + default: 0, > + description: > + "Support discard operations (requires memory-backed null_blk device). Default: false", > + }, kstrtobool again here... > -type TreeNode = Owned; > +const _CHEKC_STATUS_WIDTH: () = build_assert!((PAGE_SIZE >> SECTOR_SHIFT) <= 64); Use static_assert! or assert! here. Alice