[Devel] [PATCH] SUNRPC: make SUNPRC clients list per network namespace context

[Stanislav Kinsbursky]

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 this fater and simplier.

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

Signed-off-by: Stanislav Kinsbursky <skinsbursky at parallels.com>

---
 net/sunrpc/clnt.c        |   24 ++++++++++++++----------
 net/sunrpc/netns.h       |    3 +++
 net/sunrpc/sunrpc_syms.c |    3 +++
 3 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index f0268ea..c87f7c8 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 int	rpc_ping(struct rpc_clnt *clnt);
 
 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 int
@@ -1857,9 +1860,10 @@ void rpc_show_tasks(void)
 	struct rpc_clnt *clnt;
 	struct rpc_task *task;
 	int header = 0;
+	struct sunrpc_net *sn = net_generic(current->nsproxy->net_ns, 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) {
@@ -1870,6 +1874,6 @@ void rpc_show_tasks(void)
 		}
 		spin_unlock(&clnt->cl_lock);
 	}
-	spin_unlock(&rpc_client_lock);
+	spin_unlock(&sn->rpc_client_lock);
 }
 #endif
diff --git a/net/sunrpc/netns.h b/net/sunrpc/netns.h
index d013bf2..6010c46 100644
--- a/net/sunrpc/netns.h
+++ b/net/sunrpc/netns.h
@@ -9,6 +9,9 @@ struct cache_detail;
 struct sunrpc_net {
 	struct proc_dir_entry *proc_net_rpc;
 	struct cache_detail *ip_map_cache;
+
+	struct list_head all_clients;
+	spinlock_t rpc_client_lock;
 };
 
 extern int sunrpc_net_id;
diff --git a/net/sunrpc/sunrpc_syms.c b/net/sunrpc/sunrpc_syms.c
index 8ec9778..e57aa10 100644
--- a/net/sunrpc/sunrpc_syms.c
+++ b/net/sunrpc/sunrpc_syms.c
@@ -29,6 +29,7 @@ int sunrpc_net_id;
 static __net_init int sunrpc_init_net(struct net *net)
 {
 	int err;
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 
 	err = rpc_proc_init(net);
 	if (err)
@@ -38,6 +39,8 @@ static __net_init int sunrpc_init_net(struct net *net)
 	if (err)
 		goto err_ipmap;
 
+	INIT_LIST_HEAD(&sn->all_clients);
+	spin_lock_init(&sn->rpc_client_lock);
 	return 0;
 
 err_ipmap: