[TIPC]: Overhaul of socket locking logic
This patch modifies TIPC's socket code to follow the same approach
used by other protocols. This change eliminates the need for a
mutex in the TIPC-specific portion of the socket protocol data
structure -- in its place, the standard Linux socket backlog queue
and associated locking routines are utilized. These changes fix
a long-standing receive queue bug on SMP systems, and also enable
individual read and write threads to utilize a socket without
unnecessarily interfering with each other.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/port.c b/net/tipc/port.c
index e2646a9..2f58064 100644
--- a/net/tipc/port.c
+++ b/net/tipc/port.c
@@ -1240,6 +1240,28 @@
return res;
}
+/**
+ * tipc_disconnect_port - disconnect port from peer
+ *
+ * Port must be locked.
+ */
+
+int tipc_disconnect_port(struct tipc_port *tp_ptr)
+{
+ int res;
+
+ if (tp_ptr->connected) {
+ tp_ptr->connected = 0;
+ /* let timer expire on it's own to avoid deadlock! */
+ tipc_nodesub_unsubscribe(
+ &((struct port *)tp_ptr)->subscription);
+ res = TIPC_OK;
+ } else {
+ res = -ENOTCONN;
+ }
+ return res;
+}
+
/*
* tipc_disconnect(): Disconnect port form peer.
* This is a node local operation.
@@ -1248,17 +1270,12 @@
int tipc_disconnect(u32 ref)
{
struct port *p_ptr;
- int res = -ENOTCONN;
+ int res;
p_ptr = tipc_port_lock(ref);
if (!p_ptr)
return -EINVAL;
- if (p_ptr->publ.connected) {
- p_ptr->publ.connected = 0;
- /* let timer expire on it's own to avoid deadlock! */
- tipc_nodesub_unsubscribe(&p_ptr->subscription);
- res = TIPC_OK;
- }
+ res = tipc_disconnect_port((struct tipc_port *)p_ptr);
tipc_port_unlock(p_ptr);
return res;
}