Method lock_granularity

virtio-devices/src/block.rs:901–927

Returns the granularity for the advisory lock for this disk.

(&mut self)

    /// Returns the granularity for the advisory lock for this disk.
    fn lock_granularity(&mut self) -> LockGranularity {
        match self.lock_granularity_choice {
            LockGranularityChoice::Full => LockGranularity::WholeFile,
            LockGranularityChoice::ByteRange => {
                // Byte range lock covering [0, max(logical, physical))
                // logical > physical for sparse files, physical > logical
                // for small dense files due to filesystem block rounding.
                let logical = self.disk_image.logical_size();
                let physical = self.disk_image.physical_size();
                match (logical, physical) {
                    (Ok(l), Ok(p)) => LockGranularity::ByteRange(0, max(l, p)),
                    (Ok(l), Err(_)) => LockGranularity::ByteRange(0, l),
                    (Err(_), Ok(p)) => LockGranularity::ByteRange(0, p),
                    (Err(e), Err(_)) => {
                        let fallback = LockGranularity::WholeFile;
                        warn!(
                            "Can't get disk size for id={},path={}, falling back to {:?}: error: {e}",
                            self.id,
                            self.disk_path.display(),
                            fallback
                        );
                        fallback
                    }
                }
            }
        }
    }

    /// Tries to set an advisory lock for the corresponding disk image.
    pub fn try_lock_image(&mut self) -> Result<()> {