Function lf_update_dependancies

freebsd/kern/kern_lockf.c:1147–1166

* Re-check all dependent locks and remove edges to locks that we no * longer block. If 'all' is non-zero, the lock has been removed and * we must remove all the dependencies, otherwise it has simply been * reduced but remains active. Any pending locks which have been been * unblocked are added to 'granted' */

 * unblocked are added to 'granted'
 */
static void
lf_update_dependancies(struct lockf *state, struct lockf_entry *lock, int all,
	struct lockf_entry_list *granted)
{
	struct lockf_edge *e, *ne;
	struct lockf_entry *deplock;

	LIST_FOREACH_SAFE(e, &lock->lf_inedges, le_inlink, ne) {
		deplock = e->le_from;
		if (all || !lf_blocks(lock, deplock)) {
			sx_xlock(&lf_owner_graph_lock);
			lf_remove_edge(e);
			sx_xunlock(&lf_owner_graph_lock);
			if (LIST_EMPTY(&deplock->lf_outedges)) {
				lf_wakeup_lock(state, deplock);
				LIST_INSERT_HEAD(granted, deplock, lf_link);
			}
		}
	}
}

/*
 * Set the start of an existing active lock, updating dependencies and