[LIST]: Introduce list_for_each_entry_safe_from

For iterate over list of given type from existing point safe against removal of
list entry.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/list.h

@@ -437,6 +437,19 @@ static inline void list_splice_init(struct list_head *list,
 	     &pos->member != (head);						\
 	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
 
+/**
+ * list_for_each_entry_safe_from - iterate over list of given type
+ *			from existing point safe against removal of list entry
+ * @pos:	the type * to use as a loop counter.
+ * @n:		another type * to use as temporary storage
+ * @head:	the head for your list.
+ * @member:	the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_safe_from(pos, n, head, member) 			\
+	for (n = list_entry(pos->member.next, typeof(*pos), member);		\
+	     &pos->member != (head);						\
+	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
+
 /**
  * list_for_each_entry_safe_reverse - iterate backwards over list of given type safe against
  *				      removal of list entry