[PATCH 2/4] SUNRPC: use virtualized rpcbind internals instead of static ones

[Stanislav Kinsbursky <skinsbursky@parallels.com>]

This patch makes rpcbind logic works in network namespace context. IOW each
network namespace will have it's own unique rpcbind internals (clients and
friends) which is required for registering svc services per network namespace.

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

---
 net/sunrpc/rpcb_clnt.c |   64 ++++++++++++++++++++++++++----------------------
 1 files changed, 35 insertions(+), 29 deletions(-)

diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index c2054ae..18eba8e 100644
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -23,12 +23,15 @@
 #include <linux/errno.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
+#include <linux/nsproxy.h>
 #include <net/ipv6.h>
 
 #include <linux/sunrpc/clnt.h>
 #include <linux/sunrpc/sched.h>
 #include <linux/sunrpc/xprtsock.h>
 
+#include "netns.h"
+
 #ifdef RPC_DEBUG
 # define RPCDBG_FACILITY	RPCDBG_BIND
 #endif
@@ -111,12 +114,6 @@ static void			rpcb_getport_done(struct rpc_task *, void *);
 static void			rpcb_map_release(void *data);
 static struct rpc_program	rpcb_program;
 
-static struct rpc_clnt *	rpcb_local_clnt;
-static struct rpc_clnt *	rpcb_local_clnt4;
-
-DEFINE_SPINLOCK(rpcb_clnt_lock);
-unsigned int			rpcb_users;
-
 struct rpcbind_args {
 	struct rpc_xprt *	r_xprt;
 
@@ -167,29 +164,31 @@ static void rpcb_map_release(void *data)
 static int rpcb_get_local(void)
 {
 	int cnt;
+	struct sunrpc_net *sn = net_generic(&init_net, sunrpc_net_id);
 
-	spin_lock(&rpcb_clnt_lock);
-	if (rpcb_users)
-		rpcb_users++;
-	cnt = rpcb_users;
-	spin_unlock(&rpcb_clnt_lock);
+	spin_lock(&sn->rpcb_clnt_lock);
+	if (sn->rpcb_users)
+		sn->rpcb_users++;
+	cnt = sn->rpcb_users;
+	spin_unlock(&sn->rpcb_clnt_lock);
 
 	return cnt;
 }
 
 void rpcb_put_local(void)
 {
-	struct rpc_clnt *clnt = rpcb_local_clnt;
-	struct rpc_clnt *clnt4 = rpcb_local_clnt4;
+	struct sunrpc_net *sn = net_generic(&init_net, sunrpc_net_id);
+	struct rpc_clnt *clnt = sn->rpcb_local_clnt;
+	struct rpc_clnt *clnt4 = sn->rpcb_local_clnt4;
 	int shutdown;
 
-	spin_lock(&rpcb_clnt_lock);
-	if (--rpcb_users == 0) {
-		rpcb_local_clnt = NULL;
-		rpcb_local_clnt4 = NULL;
+	spin_lock(&sn->rpcb_clnt_lock);
+	if (--sn->rpcb_users == 0) {
+		sn->rpcb_local_clnt = NULL;
+		sn->rpcb_local_clnt4 = NULL;
 	}
-	shutdown = !rpcb_users;
-	spin_unlock(&rpcb_clnt_lock);
+	shutdown = !sn->rpcb_users;
+	spin_unlock(&sn->rpcb_clnt_lock);
 
 	if (shutdown) {
 		/*
@@ -205,14 +204,16 @@ void rpcb_put_local(void)
 
 static void rpcb_set_local(struct rpc_clnt *clnt, struct rpc_clnt *clnt4)
 {
+	struct sunrpc_net *sn = net_generic(&init_net, sunrpc_net_id);
+
 	/* Protected by rpcb_create_local_mutex */
-	rpcb_local_clnt = clnt;
-	rpcb_local_clnt4 = clnt4;
+	sn->rpcb_local_clnt = clnt;
+	sn->rpcb_local_clnt4 = clnt4;
 	smp_wmb(); 
-	rpcb_users = 1;
+	sn->rpcb_users = 1;
 	dprintk("RPC:       created new rpcb local clients (rpcb_local_clnt: "
-			"%p, rpcb_local_clnt4: %p)\n", rpcb_local_clnt,
-			rpcb_local_clnt4);
+			"%p, rpcb_local_clnt4: %p)\n", sn->rpcb_local_clnt,
+			sn->rpcb_local_clnt4);
 }
 
 /*
@@ -432,6 +433,7 @@ int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port)
 	struct rpc_message msg = {
 		.rpc_argp	= &map,
 	};
+	struct sunrpc_net *sn = net_generic(&init_net, sunrpc_net_id);
 
 	dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
 			"rpcbind\n", (port ? "" : "un"),
@@ -441,7 +443,7 @@ int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port)
 	if (port)
 		msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
 
-	return rpcb_register_call(rpcb_local_clnt, &msg);
+	return rpcb_register_call(sn->rpcb_local_clnt, &msg);
 }
 
 /*
@@ -454,6 +456,7 @@ static int rpcb_register_inet4(const struct sockaddr *sap,
 	struct rpcbind_args *map = msg->rpc_argp;
 	unsigned short port = ntohs(sin->sin_port);
 	int result;
+	struct sunrpc_net *sn = net_generic(&init_net, sunrpc_net_id);
 
 	map->r_addr = rpc_sockaddr2uaddr(sap);
 
@@ -466,7 +469,7 @@ static int rpcb_register_inet4(const struct sockaddr *sap,
 	if (port)
 		msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 
-	result = rpcb_register_call(rpcb_local_clnt4, msg);
+	result = rpcb_register_call(sn->rpcb_local_clnt4, msg);
 	kfree(map->r_addr);
 	return result;
 }
@@ -481,6 +484,7 @@ static int rpcb_register_inet6(const struct sockaddr *sap,
 	struct rpcbind_args *map = msg->rpc_argp;
 	unsigned short port = ntohs(sin6->sin6_port);
 	int result;
+	struct sunrpc_net *sn = net_generic(&init_net, sunrpc_net_id);
 
 	map->r_addr = rpc_sockaddr2uaddr(sap);
 
@@ -493,7 +497,7 @@ static int rpcb_register_inet6(const struct sockaddr *sap,
 	if (port)
 		msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 
-	result = rpcb_register_call(rpcb_local_clnt4, msg);
+	result = rpcb_register_call(sn->rpcb_local_clnt4, msg);
 	kfree(map->r_addr);
 	return result;
 }
@@ -501,6 +505,7 @@ static int rpcb_register_inet6(const struct sockaddr *sap,
 static int rpcb_unregister_all_protofamilies(struct rpc_message *msg)
 {
 	struct rpcbind_args *map = msg->rpc_argp;
+	struct sunrpc_net *sn = net_generic(&init_net, sunrpc_net_id);
 
 	dprintk("RPC:       unregistering [%u, %u, '%s'] with "
 		"local rpcbind\n",
@@ -509,7 +514,7 @@ static int rpcb_unregister_all_protofamilies(struct rpc_message *msg)
 	map->r_addr = "";
 	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 
-	return rpcb_register_call(rpcb_local_clnt4, msg);
+	return rpcb_register_call(sn->rpcb_local_clnt4, msg);
 }
 
 /**
@@ -567,8 +572,9 @@ int rpcb_v4_register(const u32 program, const u32 version,
 	struct rpc_message msg = {
 		.rpc_argp	= &map,
 	};
+	struct sunrpc_net *sn = net_generic(&init_net, sunrpc_net_id);
 
-	if (rpcb_local_clnt4 == NULL)
+	if (sn->rpcb_local_clnt4 == NULL)
 		return -EPROTONOSUPPORT;
 
 	if (address == NULL)