SUNRPC: Fix autobind on cloned rpc clients

[linux-2.6-omap-h63xx.git] / net / sunrpc / rpcb_clnt.c

diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index 24db2b4d12d3e43b3faf944262a10105ecaca898..172935b046de5a85802e0cc9ea8905b45f9b9531 100644 (file)
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -469,6 +469,28 @@ static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbi
        return rpc_run_task(&task_setup_data);
 }
 
+/*
+ * In the case where rpc clients have been cloned, we want to make
+ * sure that we use the program number/version etc of the actual
+ * owner of the xprt. To do so, we walk back up the tree of parents
+ * to find whoever created the transport and/or whoever has the
+ * autobind flag set.
+ */
+static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
+{
+       struct rpc_clnt *parent = clnt->cl_parent;
+
+       while (parent != clnt) {
+               if (parent->cl_xprt != clnt->cl_xprt)
+                       break;
+               if (clnt->cl_autobind)
+                       break;
+               clnt = parent;
+               parent = parent->cl_parent;
+       }
+       return clnt;
+}
+
 /**
  * rpcb_getport_async - obtain the port for a given RPC service on a given host
  * @task: task that is waiting for portmapper request
@@ -478,10 +500,10 @@ static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbi
  */
 void rpcb_getport_async(struct rpc_task *task)
 {
-       struct rpc_clnt *clnt = task->tk_client;
+       struct rpc_clnt *clnt;
        struct rpc_procinfo *proc;
        u32 bind_version;
-       struct rpc_xprt *xprt = task->tk_xprt;
+       struct rpc_xprt *xprt;
        struct rpc_clnt *rpcb_clnt;
        static struct rpcbind_args *map;
        struct rpc_task *child;
@@ -490,13 +512,13 @@ void rpcb_getport_async(struct rpc_task *task)
        size_t salen;
        int status;
 
+       clnt = rpcb_find_transport_owner(task->tk_client);
+       xprt = clnt->cl_xprt;
+
        dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
                task->tk_pid, __func__,
                clnt->cl_server, clnt->cl_prog, clnt->cl_vers, xprt->prot);
 
-       /* Autobind on cloned rpc clients is discouraged */
-       BUG_ON(clnt->cl_parent != clnt);
-
        /* Put self on the wait queue to ensure we get notified if
         * some other task is already attempting to bind the port */
        rpc_sleep_on(&xprt->binding, task, NULL);
@@ -578,9 +600,9 @@ void rpcb_getport_async(struct rpc_task *task)
                        task->tk_pid, __func__);
                return;
        }
-       rpc_put_task(child);
 
-       task->tk_xprt->stat.bind_count++;
+       xprt->stat.bind_count++;
+       rpc_put_task(child);
        return;
 
 bailout_nofree: