[PATCH 2/3] SUNRPC: check rpcbind clients usage counter before decrement

[Stanislav Kinsbursky <skinsbursky@parallels.com>]

Registering service with svc_bind() can fail. In this case 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>

---
 net/sunrpc/rpcb_clnt.c |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)

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) {