2008-08-13 22:41:58

by Chuck Lever

Subject: [PATCH 5/8] 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 <[email protected]>
---

net/sunrpc/svc.c | 76 +++++++++++++++++++++++++++++++++++++++++++++---------
1 files changed, 63 insertions(+), 13 deletions(-)

diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 2a6649f..58a8012 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;
}
@@ -488,8 +489,7 @@ 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);
}
@@ -729,12 +729,10 @@ 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, dummy;

- 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++) {
@@ -755,20 +753,72 @@ svc_register(struct svc_serv *serv, int proto, unsigned short port)
error = rpcb_register(progp->pg_prog, i, proto, port, &dummy);
if (error < 0)
break;
- if (port && !dummy) {
+ if (!dummy) {
error = -EACCES;
break;
}
}
}

- if (!port) {
- spin_lock_irqsave(&current->sighand->siglock, flags);
- recalc_sigpending();
- spin_unlock_irqrestore(&current->sighand->siglock, flags);
+ return error;
+}
+
+/*
+ * 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
+ * configurations, 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 (the loopback address is
+ * fairly unambiguous anyway).
+ *
+ * At this point we don't need rpcbind version 4 for unregistration:
+ * A v2 UNSET request will clear all transports (netids), addresses,
+ * and address families for [program, version].
+ *
+ * This should allow automatic support for both an all-IPv4 and
+ * an all-IPv6 configuration.
+ */
+static void __svc_unregister(struct svc_program *progp, u32 version)
+{
+ int error, boolean;
+
+ error = rpcb_register(progp->pg_prog, version, 0, 0, &boolean);
+ dprintk("svc: svc_unregister(%sv%u), error %d, %s\n",
+ progp->pg_name, version, error,
+ (boolean ? "succeeded" : "failed"));
+}
+
+/*
+ * 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.
+ */
+static void svc_unregister(const struct svc_serv *serv)
+{
+ struct svc_program *progp;
+ unsigned long flags;
+
+ clear_thread_flag(TIF_SIGPENDING);
+
+ for (progp = serv->sv_program; progp; progp = progp->pg_next) {
+ unsigned int i;
+ for (i = 0; i < progp->pg_nvers; i++) {
+ if (progp->pg_vers[i] == NULL)
+ continue;
+ if (progp->pg_vers[i]->vs_hidden)
+ continue;
+
+ __svc_unregister(progp, i);
+ }
}

- return error;
+ spin_lock_irqsave(&current->sighand->siglock, flags);
+ recalc_sigpending();
+ spin_unlock_irqrestore(&current->sighand->siglock, flags);
}

/*