Overview

dio-align reports the logical and physical block sizes required for direct I/O alignment on the filesystem backing a given path. On Linux 6.1+ it also reports the required memory alignment when statx(DIOALIGN) is available.

Installation

[dependencies]
dio-align = "0.1"

Usage

use dio_align::fetch;

fn main() -> std::io::Result<()> {
  let info = fetch("src/lib.rs")?;
  println!("logical: {}", info.logical_block_size());
  println!("physical: {}", info.physical_block_size());

  Ok(())
}

Platform notes

• Linux 6.1+: uses statx(DIOALIGN) for memory and logical alignment and sysfs for physical size.
• Linux < 6.1: uses block device ioctls and sysfs; memory alignment is not available.
• macOS and other Apple OSes: uses statfs and reports f_bsize and f_iosize.
• Windows: uses GetDiskFreeSpaceW for logical size and storage property queries for physical size. Physical size may fall back to the logical size if the query is not supported.

License

dio-align is under the terms of both the MIT license and the Apache License (Version 2.0). See LICENSE-APACHE and LICENSE-MIT for details.

Copyright (c) 2026 Al Liu.