tipc: make media xmit call outside node spinlock context

[deliverable/linux.git] / net / tipc / node.c

diff --git a/net/tipc/node.c b/net/tipc/node.c
index 19729645d494759bdc1a00560ad0631781dfdc39..ad759bb034e7d3ce34ffd56cb5c00c5600a5c7cf 100644 (file)
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -563,6 +563,84 @@ msg_full:
        return -EMSGSIZE;
 }
 
+static struct tipc_link *tipc_node_select_link(struct tipc_node *n, int sel,
+                                              int *bearer_id,
+                                              struct tipc_media_addr **maddr)
+{
+       int id = n->active_links[sel & 1];
+
+       if (unlikely(id < 0))
+               return NULL;
+
+       *bearer_id = id;
+       *maddr = &n->links[id].maddr;
+       return n->links[id].link;
+}
+
+/**
+ * tipc_node_xmit() is the general link level function for message sending
+ * @net: the applicable net namespace
+ * @list: chain of buffers containing message
+ * @dnode: address of destination node
+ * @selector: a number used for deterministic link selection
+ * Consumes the buffer chain, except when returning -ELINKCONG
+ * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
+ */
+int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
+                  u32 dnode, int selector)
+{
+       struct tipc_link *l = NULL;
+       struct tipc_node *n;
+       struct sk_buff_head xmitq;
+       struct tipc_media_addr *maddr;
+       int bearer_id;
+       int rc = -EHOSTUNREACH;
+
+       __skb_queue_head_init(&xmitq);
+       n = tipc_node_find(net, dnode);
+       if (likely(n)) {
+               tipc_node_lock(n);
+               l = tipc_node_select_link(n, selector, &bearer_id, &maddr);
+               if (likely(l))
+                       rc = tipc_link_xmit(l, list, &xmitq);
+               if (unlikely(rc == -ENOBUFS))
+                       tipc_link_reset(l);
+               tipc_node_unlock(n);
+               tipc_node_put(n);
+       }
+       if (likely(!rc)) {
+               tipc_bearer_xmit(net, bearer_id, &xmitq, maddr);
+               return 0;
+       }
+       if (likely(in_own_node(net, dnode))) {
+               tipc_sk_rcv(net, list);
+               return 0;
+       }
+       return rc;
+}
+
+/* tipc_node_xmit_skb(): send single buffer to destination
+ * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
+ * messages, which will not be rejected
+ * The only exception is datagram messages rerouted after secondary
+ * lookup, which are rare and safe to dispose of anyway.
+ * TODO: Return real return value, and let callers use
+ * tipc_wait_for_sendpkt() where applicable
+ */
+int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
+                      u32 selector)
+{
+       struct sk_buff_head head;
+       int rc;
+
+       skb_queue_head_init(&head);
+       __skb_queue_tail(&head, skb);
+       rc = tipc_node_xmit(net, &head, dnode, selector);
+       if (rc == -ELINKCONG)
+               kfree_skb(skb);
+       return 0;
+}
+
 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
 {
        int err;