SUNRPC: make SUNPRC clients list per network namespace context

This patch moves static SUNRPC clients list and it's lock to sunrpc_net
structure.
Currently this list is used only for debug purposes. But later it will be used
also for selecting clients by networks namespace on PipeFS mount/umount events.
Per-network namespace lists will make this faster and simplier.

Note: client list is taken from "init_net" network namespace context in
rpc_show_tasks(). This will be changed some day later with making SUNRPC
sysctl's per network namespace context.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 5ef192c..90e82c5 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -38,6 +38,7 @@
 #include <linux/sunrpc/bc_xprt.h>
 
 #include "sunrpc.h"
+#include "netns.h"
 
 #ifdef RPC_DEBUG
 # define RPCDBG_FACILITY	RPCDBG_CALL
@@ -50,8 +51,6 @@
 /*
  * All RPC clients are linked into this list
  */
-static LIST_HEAD(all_clients);
-static DEFINE_SPINLOCK(rpc_client_lock);
 
 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
 
@@ -81,16 +80,20 @@
 
 static void rpc_register_client(struct rpc_clnt *clnt)
 {
-	spin_lock(&rpc_client_lock);
-	list_add(&clnt->cl_clients, &all_clients);
-	spin_unlock(&rpc_client_lock);
+	struct sunrpc_net *sn = net_generic(clnt->cl_xprt->xprt_net, sunrpc_net_id);
+
+	spin_lock(&sn->rpc_client_lock);
+	list_add(&clnt->cl_clients, &sn->all_clients);
+	spin_unlock(&sn->rpc_client_lock);
 }
 
 static void rpc_unregister_client(struct rpc_clnt *clnt)
 {
-	spin_lock(&rpc_client_lock);
+	struct sunrpc_net *sn = net_generic(clnt->cl_xprt->xprt_net, sunrpc_net_id);
+
+	spin_lock(&sn->rpc_client_lock);
 	list_del(&clnt->cl_clients);
-	spin_unlock(&rpc_client_lock);
+	spin_unlock(&sn->rpc_client_lock);
 }
 
 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
@@ -1883,14 +1886,15 @@
 		task->tk_action, rpc_waitq);
 }
 
-void rpc_show_tasks(void)
+void rpc_show_tasks(struct net *net)
 {
 	struct rpc_clnt *clnt;
 	struct rpc_task *task;
 	int header = 0;
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 
-	spin_lock(&rpc_client_lock);
-	list_for_each_entry(clnt, &all_clients, cl_clients) {
+	spin_lock(&sn->rpc_client_lock);
+	list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 		spin_lock(&clnt->cl_lock);
 		list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
 			if (!header) {
@@ -1901,6 +1905,6 @@
 		}
 		spin_unlock(&clnt->cl_lock);
 	}
-	spin_unlock(&rpc_client_lock);
+	spin_unlock(&sn->rpc_client_lock);
 }
 #endif