SUNRPC: Fix an RCU dereference in xprt_reserve

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
git-mirror · Feb 1, 2013 · 45bc0dc · 45bc0dc
1 parent 6a24dfb
commit 45bc0dc
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
@@ -1093,15 +1093,18 @@ EXPORT_SYMBOL_GPL(xprt_free);
  */
 void xprt_reserve(struct rpc_task *task)
 {
-	struct rpc_xprt	*xprt = task->tk_xprt;
+	struct rpc_xprt	*xprt;
 
 	task->tk_status = 0;
 	if (task->tk_rqstp != NULL)
 		return;
 
 	task->tk_timeout = 0;
 	task->tk_status = -EAGAIN;
+	rcu_read_lock();
+	xprt = rcu_dereference(task->tk_client->cl_xprt);
 	xprt->ops->alloc_slot(xprt, task);
+	rcu_read_unlock();
 }
 
 static inline __be32 xprt_alloc_xid(struct rpc_xprt *xprt)