[PATCH v3 1/2] SUNRPC: new svc_bind() routine introduced

[Stanislav Kinsbursky <skinsbursky@parallels.com>]

v3: this patch was squashed with the "SUNRPC: check rpcbind clients usage
counter before decrement" patch.

New routine is responsible for service registration in specified network
context.
The idea is to separate service creation from per-net operations.
Since registering service with svc_bind() can fail, then service will be
destroyed and during destruction it will try to unregister itself from
rpcbind. In this case unregister have to be skipped.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
---
 fs/lockd/svc.c             |    6 ++++++
 fs/nfs/callback.c          |    8 ++++++++
 fs/nfsd/nfssvc.c           |    9 +++++++++
 include/linux/sunrpc/svc.h |    1 +
 net/sunrpc/rpcb_clnt.c     |   12 +++++++-----
 net/sunrpc/svc.c           |   19 ++++++++++---------
 6 files changed, 41 insertions(+), 14 deletions(-)

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 1ead075..b7e92ed 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -324,6 +324,12 @@ int lockd_up(struct net *net)
 		goto out;
 	}
 
+	error = svc_bind(serv, net);
+	if (error < 0) {
+		printk(KERN_WARNING "lockd_up: bind service failed\n");
+		goto destroy_and_out;
+	}
+
 	error = make_socks(serv, net);
 	if (error < 0)
 		goto destroy_and_out;
diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index eb95f50..26b38fb 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -17,6 +17,7 @@
 #include <linux/kthread.h>
 #include <linux/sunrpc/svcauth_gss.h>
 #include <linux/sunrpc/bc_xprt.h>
+#include <linux/nsproxy.h>
 
 #include <net/inet_sock.h>
 
@@ -253,6 +254,7 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
 	char svc_name[12];
 	int ret = 0;
 	int minorversion_setup;
+	struct net *net = current->nsproxy->net_ns;
 
 	mutex_lock(&nfs_callback_mutex);
 	if (cb_info->users++ || cb_info->task != NULL) {
@@ -265,6 +267,12 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
 		goto out_err;
 	}
 
+	ret = svc_bind(serv, net);
+	if (ret < 0) {
+		printk(KERN_WARNING "NFS: bind callback service failed\n");
+		goto out_err;
+	}
+
 	minorversion_setup =  nfs_minorversion_callback_svc_setup(minorversion,
 					serv, xprt, &rqstp, &callback_svc);
 	if (!minorversion_setup) {
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index cb4d51d..0762f3c 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -11,6 +11,7 @@
 #include <linux/module.h>
 #include <linux/fs_struct.h>
 #include <linux/swap.h>
+#include <linux/nsproxy.h>
 
 #include <linux/sunrpc/stats.h>
 #include <linux/sunrpc/svcsock.h>
@@ -330,6 +331,8 @@ static int nfsd_get_default_max_blksize(void)
 
 int nfsd_create_serv(void)
 {
+	int error;
+
 	WARN_ON(!mutex_is_locked(&nfsd_mutex));
 	if (nfsd_serv) {
 		svc_get(nfsd_serv);
@@ -343,6 +346,12 @@ int nfsd_create_serv(void)
 	if (nfsd_serv == NULL)
 		return -ENOMEM;
 
+	error = svc_bind(nfsd_serv, current->nsproxy->net_ns);
+	if (error < 0) {
+		svc_destroy(nfsd_serv);
+		return error;
+	}
+
 	set_max_drc();
 	do_gettimeofday(&nfssvc_boot);		/* record boot time */
 	return 0;
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 51b29ac..2b43e02 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -416,6 +416,7 @@ struct svc_procedure {
  */
 int svc_rpcb_setup(struct svc_serv *serv, struct net *net);
 void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net);
+int svc_bind(struct svc_serv *serv, struct net *net);
 struct svc_serv *svc_create(struct svc_program *, unsigned int,
 			    void (*shutdown)(struct svc_serv *, struct net *net));
 struct svc_rqst *svc_prepare_thread(struct svc_serv *serv,
diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index 78ac39f..4c38b33 100644
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -180,14 +180,16 @@ void rpcb_put_local(struct net *net)
 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 	struct rpc_clnt *clnt = sn->rpcb_local_clnt;
 	struct rpc_clnt *clnt4 = sn->rpcb_local_clnt4;
-	int shutdown;
+	int shutdown = 0;
 
 	spin_lock(&sn->rpcb_clnt_lock);
-	if (--sn->rpcb_users == 0) {
-		sn->rpcb_local_clnt = NULL;
-		sn->rpcb_local_clnt4 = NULL;
+	if (sn->rpcb_users) {
+		if (--sn->rpcb_users == 0) {
+			sn->rpcb_local_clnt = NULL;
+			sn->rpcb_local_clnt4 = NULL;
+		}
+		shutdown = !sn->rpcb_users;
 	}
-	shutdown = !sn->rpcb_users;
 	spin_unlock(&sn->rpcb_clnt_lock);
 
 	if (shutdown) {
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 4153846..e6d542c 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -407,6 +407,14 @@ static int svc_uses_rpcbind(struct svc_serv *serv)
 	return 0;
 }
 
+int svc_bind(struct svc_serv *serv, struct net *net)
+{
+	if (!svc_uses_rpcbind(serv))
+		return 0;
+	return svc_rpcb_setup(serv, net);
+}
+EXPORT_SYMBOL_GPL(svc_bind);
+
 /*
  * Create an RPC service
  */
@@ -471,15 +479,8 @@ __svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
 		spin_lock_init(&pool->sp_lock);
 	}
 
-	if (svc_uses_rpcbind(serv)) {
-		if (svc_rpcb_setup(serv, current->nsproxy->net_ns) < 0) {
-			kfree(serv->sv_pools);
-			kfree(serv);
-			return NULL;
-		}
-		if (!serv->sv_shutdown)
-			serv->sv_shutdown = svc_rpcb_cleanup;
-	}
+	if (svc_uses_rpcbind(serv) && (!serv->sv_shutdown))
+		serv->sv_shutdown = svc_rpcb_cleanup;
 
 	return serv;
 }