[PATCH v7 4/7] SUNRPC: setup rpcbind clients if service requires it

[Stanislav Kinsbursky <skinsbursky@parallels.com>]

New function ("svc_uses_rpcbind") will be used to detect, that new service will
send portmapper register calls. For such services we will create rpcbind
clients and remove all stale portmap registrations.
Also, svc_rpcb_cleanup() will be set as sv_shutdown callback for such services
in case of this field wasn't initialized earlier. This will allow to destroy
rpcbind clients when no other users of them left.

Note: Currently, any creating service will be detected as portmap user.
Probably, this is wrong. But now it depends on program versions "vs_hidden"
flag.

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

---
 net/sunrpc/svc.c |   20 ++++++++++++++------
 1 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index d2d61bf..87a67b2 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -436,10 +436,8 @@ __svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
 	serv->sv_pools =
 		kcalloc(serv->sv_nrpools, sizeof(struct svc_pool),
 			GFP_KERNEL);
-	if (!serv->sv_pools) {
-		kfree(serv);
-		return NULL;
-	}
+	if (!serv->sv_pools)
+		goto err_serv;
 
 	for (i = 0; i < serv->sv_nrpools; i++) {
 		struct svc_pool *pool = &serv->sv_pools[i];
@@ -454,10 +452,20 @@ __svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
 		spin_lock_init(&pool->sp_lock);
 	}
 
-	/* Remove any stale portmap registrations */
-	svc_unregister(serv);
+	if (svc_uses_rpcbind(serv)) {
+	       	if (svc_rpcb_setup(serv) < 0)
+			goto err_rpcb;
+		if (!serv->sv_shutdown)
+			serv->sv_shutdown = svc_rpcb_cleanup;
+	}
 
 	return serv;
+
+err_rpcb:
+	kfree(serv->sv_pools);
+err_serv:
+	kfree(serv);
+	return NULL;
 }
 
 struct svc_serv *