seq_file: add RCU versions of new hlist/list iterators (v3)
Many usages of seq_file use RCU protected lists, so non RCU
iterators will not work safely.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/rculist.h b/include/linux/rculist.h
index 1bf0f70..701fe9c 100644
--- a/include/linux/rculist.h
+++ b/include/linux/rculist.h
@@ -406,6 +406,11 @@
n->next->pprev = &n->next;
}
+#define __hlist_for_each_rcu(pos, head) \
+ for (pos = rcu_dereference((head)->first); \
+ pos && ({ prefetch(pos->next); 1; }); \
+ pos = rcu_dereference(pos->next))
+
/**
* hlist_for_each_entry_rcu - iterate over rcu list of given type
* @tpos: the type * to use as a loop cursor.
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index c95bcdc..03c0232 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -140,10 +140,17 @@
*/
extern struct hlist_node *seq_hlist_start(struct hlist_head *head,
- loff_t pos);
+ loff_t pos);
extern struct hlist_node *seq_hlist_start_head(struct hlist_head *head,
- loff_t pos);
+ loff_t pos);
extern struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head,
- loff_t *ppos);
+ loff_t *ppos);
+extern struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head,
+ loff_t pos);
+extern struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head,
+ loff_t pos);
+extern struct hlist_node *seq_hlist_next_rcu(void *v,
+ struct hlist_head *head,
+ loff_t *ppos);
#endif