int ulist_add(struct ulist *ulist, u64 val, u64 aux, gfp_t gfp_mask);
int ulist_add_merge(struct ulist *ulist, u64 val, u64 aux,
u64 *old_aux, gfp_t gfp_mask);
+int ulist_del(struct ulist *ulist, u64 val, u64 aux);
/* just like ulist_add_merge() but take a pointer for the aux data */
static inline int ulist_add_merge_ptr(struct ulist *ulist, u64 val, void *aux,