Diffstat (limited to 'include/linux/llist.h')
1 files changed, 25 insertions, 0 deletions
diff --git a/include/linux/llist.h b/include/linux/llist.h
index a5199f6d0e8..d0ab98f73d3 100644
@@ -125,6 +125,31 @@ static inline void init_llist_head(struct llist_head *list)
(pos) = llist_entry((pos)->member.next, typeof(*(pos)), member))
+ * llist_for_each_entry_safe - iterate safely against remove over some entries
+ * of lock-less list of given type.
+ * @pos: the type * to use as a loop cursor.
+ * @n: another type * to use as a temporary storage.
+ * @node: the fist entry of deleted list entries.
+ * @member: the name of the llist_node with the struct.
+ * In general, some entries of the lock-less list can be traversed
+ * safely only after being removed from list, so start with an entry
+ * instead of list head. This variant allows removal of entries
+ * as we iterate.
+ * If being used on entries deleted from lock-less list directly, the
+ * traverse order is from the newest to the oldest added entry. If
+ * you want to traverse from the oldest to the newest, you must
+ * reverse the order by yourself before traversing.
+#define llist_for_each_entry_safe(pos, n, node, member) \
+ for ((pos) = llist_entry((node), typeof(*(pos)), member), \
+ (n) = (pos)->member.next; \
+ &(pos)->member != NULL; \
+ (pos) = llist_entry(n, typeof(*(pos)), member), \
+ (n) = (&(pos)->member != NULL) ? (pos)->member.next : NULL)
* llist_empty - tests whether a lock-less list is empty
* @head: the list to test