SUNRPC: Split portmap unregister API into separate function

Create a separate server-level interface for unregistering RPC services.

The mechanics of, and the API for, registering and unregistering RPC
services will diverge further as support for IPv6 is added.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

1 files changed, 50 insertions, 12 deletions

diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 9805143d0660..9eb78a771da5 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -28,6 +28,8 @@
 
 #define RPCDBG_FACILITY RPCDBG_SVCDSP
 
+static void svc_unregister(const struct svc_serv *serv);
+
 #define svc_serv_is_pooled(serv)    ((serv)->sv_function)
 
 /*
@@ -417,9 +419,8 @@ __svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
                 spin_lock_init(&pool->sp_lock);
         }
 
-
         /* Remove any stale portmap registrations */
-        svc_register(serv, 0, 0);
+        svc_unregister(serv);
 
         return serv;
 }
@@ -487,8 +488,7 @@ svc_destroy(struct svc_serv *serv)
         if (svc_serv_is_pooled(serv))
                 svc_pool_map_put();
 
-        /* Unregister service with the portmapper */
-        svc_register(serv, 0, 0);
+        svc_unregister(serv);
         kfree(serv->sv_pools);
         kfree(serv);
 }
@@ -728,12 +728,10 @@ int
 svc_register(struct svc_serv *serv, int proto, unsigned short port)
 {
         struct svc_program      *progp;
-        unsigned long           flags;
         unsigned int            i;
         int                     error = 0;
 
-        if (!port)
-                clear_thread_flag(TIF_SIGPENDING);
+        BUG_ON(proto == 0 && port == 0);
 
         for (progp = serv->sv_program; progp; progp = progp->pg_next) {
                 for (i = 0; i < progp->pg_nvers; i++) {
@@ -757,13 +755,53 @@ svc_register(struct svc_serv *serv, int proto, unsigned short port)
                 }
         }
 
-        if (!port) {
-                spin_lock_irqsave(&current->sighand->siglock, flags);
-                recalc_sigpending();
-                spin_unlock_irqrestore(&current->sighand->siglock, flags);
+        return error;
+}
+
+/*
+ * All transport protocols and ports for this service are removed
+ * from the local rpcbind database if the service is not hidden.
+ *
+ * The result of unregistration is reported via dprintk for those
+ * who want verification of the result, but is otherwise not
+ * important.
+ *
+ * The local rpcbind daemon listens on either only IPv6 or only
+ * IPv4.  The kernel can't tell how it's configured.  However,
+ * AF_INET addresses are mapped to AF_INET6 in IPv6-only config-
+ * urations, so even an unregistration request on AF_INET will
+ * get to a local rpcbind daemon listening only on AF_INET6.  So
+ * we always unregister via AF_INET.
+ *
+ * At this point we don't need rpcbind version 4 for unregis-
+ * tration:  A v2 UNSET request will clear all transports (netids),
+ * addresses, and address families for [program, version].
+ */
+static void svc_unregister(const struct svc_serv *serv)
+{
+        struct svc_program *progp;
+        unsigned long flags;
+        unsigned int i;
+        int error;
+
+        clear_thread_flag(TIF_SIGPENDING);
+
+        for (progp = serv->sv_program; progp; progp = progp->pg_next) {
+                for (i = 0; i < progp->pg_nvers; i++) {
+                        if (progp->pg_vers[i] == NULL)
+                                continue;
+                        if (progp->pg_vers[i]->vs_hidden)
+                                continue;
+
+                        error = rpcb_register(progp->pg_prog, i, 0, 0);
+                        dprintk("svc: svc_unregister(%sv%u), error %d\n",
+                                        progp->pg_name, i, error);
+                }
         }
 
-        return error;
+        spin_lock_irqsave(&current->sighand->siglock, flags);
+        recalc_sigpending();
+        spin_unlock_irqrestore(&current->sighand->siglock, flags);
 }
 
 /*