list_bl: Add hlist_bl_add_before/behind helpers (34191ae8) · Commits · 戴 / test

Add hlist_bl_add_before/behind helpers to add an element before/after an existing element in a bl_list. Co-developed-by:

include/linux/list_bl.h

+26 −0

Original line number	Diff line number	Diff line
		@@ -86,6 +86,32 @@ static inline void hlist_bl_add_head(struct hlist_bl_node *n,
		hlist_bl_set_first(h, n);
		}

		static inline void hlist_bl_add_before(struct hlist_bl_node *n,
		struct hlist_bl_node *next)
		{
		struct hlist_bl_node **pprev = next->pprev;

		n->pprev = pprev;
		n->next = next;
		next->pprev = &n->next;

		/* pprev may be `first`, so be careful not to lose the lock bit */
		WRITE_ONCE(*pprev,
		(struct hlist_bl_node *)
		((uintptr_t)n \| ((uintptr_t)*pprev & LIST_BL_LOCKMASK)));
		}

		static inline void hlist_bl_add_behind(struct hlist_bl_node *n,
		struct hlist_bl_node *prev)
		{
		n->next = prev->next;
		n->pprev = &prev->next;
		prev->next = n;

		if (n->next)
		n->next->pprev = &n->next;
		}

		static inline void __hlist_bl_del(struct hlist_bl_node *n)
		{
		struct hlist_bl_node *next = n->next;