pub fn cas_lock_path(root: &Path) -> PathBufExpand description
Store-wide lock separating extraction from collection.
Extraction holds it shared while it populates the content store, because a blob is briefly reachable only from the store itself: it is renamed into place before being hardlinked into the package tree, and in that window its link count does not yet reflect the reference that is about to exist. Collection holds it exclusive, which proves no extraction is inside that window and therefore that link counts can be trusted.