Commit 1ac252ad authored by Julian Anastasov's avatar Julian Anastasov Committed by Florian Westphal
Browse files

rculist_bl: add hlist_bl_for_each_entry_continue_rcu 



Change the old hlist_bl_first_rcu to hlist_bl_first_rcu_dereference
to indicate that it is a RCU dereference.

Add hlist_bl_next_rcu and hlist_bl_first_rcu to use RCU pointers
and use them to fix sparse warnings.

Add hlist_bl_for_each_entry_continue_rcu.

Signed-off-by: default avatarJulian Anastasov <ja@ssi.bg>
Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
parent 34a6a003

include/linux/rculist_bl.h

+40 −9
Original line number Diff line number Diff line
@@ -8,21 +8,31 @@ 
#include <linux/list_bl.h>

#include <linux/rcupdate.h>



/* return the first ptr or next element in an RCU protected list */

#define hlist_bl_first_rcu(head)	\

	(*((struct hlist_bl_node __rcu **)(&(head)->first)))

#define hlist_bl_next_rcu(node)	\

	(*((struct hlist_bl_node __rcu **)(&(node)->next)))



static inline void hlist_bl_set_first_rcu(struct hlist_bl_head *h,

					struct hlist_bl_node *n)

{

	LIST_BL_BUG_ON((unsigned long)n & LIST_BL_LOCKMASK);

	LIST_BL_BUG_ON(((unsigned long)h->first & LIST_BL_LOCKMASK) !=

							LIST_BL_LOCKMASK);

	rcu_assign_pointer(h->first,

	rcu_assign_pointer(hlist_bl_first_rcu(h),

		(struct hlist_bl_node *)((unsigned long)n | LIST_BL_LOCKMASK));

}



static inline struct hlist_bl_node *hlist_bl_first_rcu(struct hlist_bl_head *h)

{

	return (struct hlist_bl_node *)

		((unsigned long)rcu_dereference_check(h->first, hlist_bl_is_locked(h)) & ~LIST_BL_LOCKMASK);

}

#define hlist_bl_first_rcu_dereference(head)				\

({									\

	struct hlist_bl_head *__head = (head);				\

									\

	(struct hlist_bl_node *)					\

	((unsigned long)rcu_dereference_check(hlist_bl_first_rcu(__head), \

					      hlist_bl_is_locked(__head)) & \

					      ~LIST_BL_LOCKMASK);	\

})



/**

 * hlist_bl_del_rcu - deletes entry from hash list without re-initialization
@@ -73,7 +83,7 @@ static inline void hlist_bl_add_head_rcu(struct hlist_bl_node *n, 
{

	struct hlist_bl_node *first;



	/* don't need hlist_bl_first_rcu because we're under lock */

	/* don't need hlist_bl_first_rcu* because we're under lock */

	first = hlist_bl_first(h);



	n->next = first;
@@ -93,9 +103,30 @@ static inline void hlist_bl_add_head_rcu(struct hlist_bl_node *n, 
 *

 */

#define hlist_bl_for_each_entry_rcu(tpos, pos, head, member)		\

	for (pos = hlist_bl_first_rcu(head);				\

	for (pos = hlist_bl_first_rcu_dereference(head);		\

		pos &&							\

		({ tpos = hlist_bl_entry(pos, typeof(*tpos), member); 1; }); \

		pos = rcu_dereference_raw(hlist_bl_next_rcu(pos)))



/**

 * hlist_bl_for_each_entry_continue_rcu - continue iteration over list of given

 *   type

 * @tpos:	the type * to use as a loop cursor.

 * @pos:	the &struct hlist_bl_node to use as a loop cursor.

 * @member:	the name of the hlist_bl_node within the struct.

 *

 * Continue to iterate over list of given type, continuing after

 * the current position which must have been in the list when the RCU read

 * lock was taken.

 * This would typically require either that you obtained the node from a

 * previous walk of the list in the same RCU read-side critical section, or

 * that you held some sort of non-RCU reference (such as a reference count)

 * to keep the node alive *and* in the list.

 */

#define hlist_bl_for_each_entry_continue_rcu(tpos, pos, member)		\

	for (pos = rcu_dereference_raw(hlist_bl_next_rcu(&(tpos)->member)); \

	     pos &&							\

	     ({ tpos = hlist_bl_entry(pos, typeof(*tpos), member); 1; }); \

		pos = rcu_dereference_raw(pos->next))

	     pos = rcu_dereference_raw(hlist_bl_next_rcu(pos)))



#endif