pub fn gate(free: u64, min_free: u64) -> Option<String>Expand description
Why a run must not start, given measured free bytes and the floor —
None means the gate is open. Pure, so the policy is asserted directly.
A gate that cannot measure also closes (see [crate::daemon::disk_gate]):
starting a run on a disk that may already be full is the incident this
whole module exists to prevent.