// metacacheSharePrefix controls whether prefixes on dirty paths are always shared.
	// This will make `test/a` and `test/b` share listings if they are concurrent.
	// Enabling this will make cache sharing more likely and cause less IO,
	// but may cause additional latency to some calls.
	metacacheSharePrefix = false
)

//go:generate msgp -file $GOFILE -unexported

// metacache contains a tracked cache entry.