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authorDavid S. Miller <davem@davemloft.net>2016-04-23 18:26:24 -0400
committerDavid S. Miller <davem@davemloft.net>2016-04-23 18:51:33 -0400
commit1602f49b58abcb0d34a5f0a29d68e7c1769547aa (patch)
tree4848fb0ffbc581ff465fd9c9e5a5b10b06f09b68 /include/linux/rculist.h
parent22d37b6b0058365a80378ee6198d21e7f6c86327 (diff)
parent5f44abd041c5f3be76d57579ab254d78e601315b (diff)
downloadlwn-1602f49b58abcb0d34a5f0a29d68e7c1769547aa.tar.gz
lwn-1602f49b58abcb0d34a5f0a29d68e7c1769547aa.zip
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts were two cases of simple overlapping changes, nothing serious. In the UDP case, we need to add a hlist_add_tail_rcu() to linux/rculist.h, because we've moved UDP socket handling away from using nulls lists. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/rculist.h')
-rw-r--r--include/linux/rculist.h36
1 files changed, 36 insertions, 0 deletions
diff --git a/include/linux/rculist.h b/include/linux/rculist.h
index 17d4f849c65e..8beb98dcf14f 100644
--- a/include/linux/rculist.h
+++ b/include/linux/rculist.h
@@ -488,6 +488,42 @@ static inline void hlist_add_head_rcu(struct hlist_node *n,
}
/**
+ * hlist_add_tail_rcu
+ * @n: the element to add to the hash list.
+ * @h: the list to add to.
+ *
+ * Description:
+ * Adds the specified element to the specified hlist,
+ * while permitting racing traversals.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as hlist_add_head_rcu()
+ * or hlist_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * hlist_for_each_entry_rcu(), used to prevent memory-consistency
+ * problems on Alpha CPUs. Regardless of the type of CPU, the
+ * list-traversal primitive must be guarded by rcu_read_lock().
+ */
+static inline void hlist_add_tail_rcu(struct hlist_node *n,
+ struct hlist_head *h)
+{
+ struct hlist_node *i, *last = NULL;
+
+ for (i = hlist_first_rcu(h); i; i = hlist_next_rcu(i))
+ last = i;
+
+ if (last) {
+ n->next = last->next;
+ n->pprev = &last->next;
+ rcu_assign_pointer(hlist_next_rcu(last), n);
+ } else {
+ hlist_add_head_rcu(n, h);
+ }
+}
+
+/**
* hlist_add_before_rcu
* @n: the new element to add to the hash list.
* @next: the existing element to add the new element before.