Struct CowOptions 

pub struct CowOptions {
    pub data_dir: PathBuf,
    pub block_tools: Arc<dyn BlockTools>,
    pub dmsetup_candidates: Vec<PathBuf>,
}

What a CowManager needs from its environment.

CowOptions::new fills in the reference environment — the System VM’s userland — so today’s callers pass a data directory and nothing else; a composer on a different userland overrides the fields it owns.

Fields

data_dir: PathBuf

Data directory; COW files live under {data_dir}/cow/.

block_tools: Arc<dyn BlockTools>

Loop-device and block-size operations.

dmsetup_candidates: Vec<PathBuf>

Where to look for dmsetup. The first entry that exists and answers dmsetup version is used; none usable degrades the manager to copy-mode fallback (every setup fails with an actionable error).

Implementations

impl CowOptions

pub fn new(data_dir: impl Into<PathBuf>) -> CowOptions

The reference environment: busybox at BusyboxBlockTools::DEFAULT_PATH and the stock-distro dmsetup search list.