Method new

crates/blockdev/src/blockdev.rs:521–563

Create a new loopback block device targeting the provided file path.

(path: &Path)

impl LoopbackDevice {
    // Create a new loopback block device targeting the provided file path.
    pub fn new(path: &Path) -> Result<Self> {
        let direct_io = match env::var("BOOTC_DIRECT_IO") {
            Ok(val) => {
                if val == "on" {
                    "on"
                } else {
                    "off"
                }
            }
            Err(_e) => "off",
        };

        let dev = Command::new("losetup")
            .args([
                "--show",
                format!("--direct-io={direct_io}").as_str(),
                "-P",
                "--find",
            ])
            .arg(path)
            .run_get_string()?;
        let dev = Utf8PathBuf::from(dev.trim());
        tracing::debug!("Allocated loopback {dev}");

        // Try to spawn cleanup helper, but don't fail if it doesn't work
        let cleanup_handle = match Self::spawn_cleanup_helper(dev.as_str()) {
            Ok(handle) => Some(handle),
            Err(e) => {
                tracing::warn!(
                    "Failed to spawn loopback cleanup helper for {}: {}. \
                     Loopback device may not be cleaned up if process is interrupted.",
                    dev,
                    e
                );
                None
            }
        };

        Ok(Self {
            dev: Some(dev),
            cleanup_handle,
        })
    }

    // Access the path to the loopback block device.
    pub fn path(&self) -> &Utf8Path {