tipc: remove port_lock

In previous commits we have reduced usage of port_lock to a minimum,
and complemented it with usage of bh_lock_sock() at the remaining
locations. The purpose has been to remove this lock altogether, since
it largely duplicates the role of bh_lock_sock. We are now ready to do
this.

However, we still need to protect the BH callers from inadvertent
release of the socket while they hold a reference to it. We do this by
replacing port_lock by a combination of a rw-lock protecting the
reference table as such, and updating the socket reference counter while
the socket is referenced from BH. This technique is more standard and
comprehensible than the previous approach, and turns out to have a
positive effect on overall performance.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 4 deletions

diff --git a/net/tipc/ref.h b/net/tipc/ref.h
index e236fa520a1d..2b75a892305a 100644
--- a/net/tipc/ref.h
+++ b/net/tipc/ref.h
@@ -1,7 +1,7 @@
 /*
  * net/tipc/ref.h: Include file for TIPC object registry code
  *
- * Copyright (c) 1991-2006, Ericsson AB
+ * Copyright (c) 1991-2006, 2014, Ericsson AB
  * Copyright (c) 2005-2006, Wind River Systems
  * All rights reserved.
  *
@@ -37,13 +37,20 @@
 #ifndef _TIPC_REF_H
 #define _TIPC_REF_H
 
+#include "socket.h"
+
 int tipc_ref_table_init(u32 requested_size, u32 start);
 void tipc_ref_table_stop(void);
 
-u32 tipc_ref_acquire(void *object, spinlock_t **lock);
+u32 tipc_ref_acquire(struct tipc_sock *tsk);
 void tipc_ref_discard(u32 ref);
 
-void *tipc_ref_lock(u32 ref);
-void *tipc_ref_lock_next(u32 *ref);
+struct tipc_sock *tipc_sk_get(u32 ref);
+struct tipc_sock *tipc_sk_get_next(u32 *ref);
+
+static inline void tipc_sk_put(struct tipc_sock *tsk)
+{
+	sock_put(&tsk->sk);
+}
 
 #endif