SUNRPC: Use a cached RPC client and transport for rpcbind upcalls
The kernel's rpcbind client creates and deletes an rpc_clnt and its
underlying transport socket for every upcall to the local rpcbind
daemon.
When starting a typical NFS server on IPv4 and IPv6, the NFS service
itself does three upcalls (one per version) times two upcalls (one
per transport) times two upcalls (one per address family), making 12,
plus another one for the initial call to unregister previous NFS
services. Starting the NLM service adds an additional 13 upcalls,
for similar reasons.
(Currently the NFS service doesn't start IPv6 listeners, but it will
soon enough).
Instead, let's create an rpc_clnt for rpcbind upcalls during the
first local rpcbind query, and cache it. This saves the overhead of
creating and destroying an rpc_clnt and a socket for every upcall.
The new logic also prevents the kernel from attempting an RPCB_SET or
RPCB_UNSET if it knows from the start that the local portmapper does
not support rpcbind protocol version 4. This will cut down on the
number of rpcbind upcalls in legacy environments.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index 28f50da..116db74 100644
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -20,6 +20,7 @@
#include <linux/in6.h>
#include <linux/kernel.h>
#include <linux/errno.h>
+#include <linux/mutex.h>
#include <net/ipv6.h>
#include <linux/sunrpc/clnt.h>
@@ -110,6 +111,9 @@
static void rpcb_map_release(void *data);
static struct rpc_program rpcb_program;
+static struct rpc_clnt * rpcb_local_clnt;
+static struct rpc_clnt * rpcb_local_clnt4;
+
struct rpcbind_args {
struct rpc_xprt * r_xprt;
@@ -163,7 +167,13 @@
.sin_port = htons(RPCBIND_PORT),
};
-static struct rpc_clnt *rpcb_create_local(u32 version)
+static DEFINE_MUTEX(rpcb_create_local_mutex);
+
+/*
+ * Returns zero on success, otherwise a negative errno value
+ * is returned.
+ */
+static int rpcb_create_local(void)
{
struct rpc_create_args args = {
.protocol = XPRT_TRANSPORT_UDP,
@@ -171,12 +181,46 @@
.addrsize = sizeof(rpcb_inaddr_loopback),
.servername = "localhost",
.program = &rpcb_program,
- .version = version,
+ .version = RPCBVERS_2,
.authflavor = RPC_AUTH_UNIX,
.flags = RPC_CLNT_CREATE_NOPING,
};
+ struct rpc_clnt *clnt, *clnt4;
+ int result = 0;
- return rpc_create(&args);
+ if (rpcb_local_clnt)
+ return result;
+
+ mutex_lock(&rpcb_create_local_mutex);
+ if (rpcb_local_clnt)
+ goto out;
+
+ clnt = rpc_create(&args);
+ if (IS_ERR(clnt)) {
+ dprintk("RPC: failed to create local rpcbind "
+ "client (errno %ld).\n", PTR_ERR(clnt));
+ result = -PTR_ERR(clnt);
+ goto out;
+ }
+
+ /*
+ * This results in an RPC ping. On systems running portmapper,
+ * the v4 ping will fail. Proceed anyway, but disallow rpcb
+ * v4 upcalls.
+ */
+ clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
+ if (IS_ERR(clnt4)) {
+ dprintk("RPC: failed to create local rpcbind v4 "
+ "cleint (errno %ld).\n", PTR_ERR(clnt4));
+ clnt4 = NULL;
+ }
+
+ rpcb_local_clnt = clnt;
+ rpcb_local_clnt4 = clnt4;
+
+out:
+ mutex_unlock(&rpcb_create_local_mutex);
+ return result;
}
static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr,
@@ -208,20 +252,13 @@
return rpc_create(&args);
}
-static int rpcb_register_call(const u32 version, struct rpc_message *msg)
+static int rpcb_register_call(struct rpc_clnt *clnt, struct rpc_message *msg)
{
- struct rpc_clnt *rpcb_clnt;
int result, error = 0;
msg->rpc_resp = &result;
- rpcb_clnt = rpcb_create_local(version);
- if (!IS_ERR(rpcb_clnt)) {
- error = rpc_call_sync(rpcb_clnt, msg, 0);
- rpc_shutdown_client(rpcb_clnt);
- } else
- error = PTR_ERR(rpcb_clnt);
-
+ error = rpc_call_sync(clnt, msg, 0);
if (error < 0) {
dprintk("RPC: failed to contact local rpcbind "
"server (errno %d).\n", -error);
@@ -276,6 +313,11 @@
struct rpc_message msg = {
.rpc_argp = &map,
};
+ int error;
+
+ error = rpcb_create_local();
+ if (error)
+ return error;
dprintk("RPC: %sregistering (%u, %u, %d, %u) with local "
"rpcbind\n", (port ? "" : "un"),
@@ -285,7 +327,7 @@
if (port)
msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
- return rpcb_register_call(RPCBVERS_2, &msg);
+ return rpcb_register_call(rpcb_local_clnt, &msg);
}
/*
@@ -310,7 +352,7 @@
if (port)
msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
- result = rpcb_register_call(RPCBVERS_4, msg);
+ result = rpcb_register_call(rpcb_local_clnt4, msg);
kfree(map->r_addr);
return result;
}
@@ -337,7 +379,7 @@
if (port)
msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
- result = rpcb_register_call(RPCBVERS_4, msg);
+ result = rpcb_register_call(rpcb_local_clnt4, msg);
kfree(map->r_addr);
return result;
}
@@ -353,7 +395,7 @@
map->r_addr = "";
msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
- return rpcb_register_call(RPCBVERS_4, msg);
+ return rpcb_register_call(rpcb_local_clnt4, msg);
}
/**
@@ -411,6 +453,13 @@
struct rpc_message msg = {
.rpc_argp = &map,
};
+ int error;
+
+ error = rpcb_create_local();
+ if (error)
+ return error;
+ if (rpcb_local_clnt4 == NULL)
+ return -EPROTONOSUPPORT;
if (address == NULL)
return rpcb_unregister_all_protofamilies(&msg);
@@ -1024,3 +1073,15 @@
.version = rpcb_version,
.stats = &rpcb_stats,
};
+
+/**
+ * cleanup_rpcb_clnt - remove xprtsock's sysctls, unregister
+ *
+ */
+void cleanup_rpcb_clnt(void)
+{
+ if (rpcb_local_clnt4)
+ rpc_shutdown_client(rpcb_local_clnt4);
+ if (rpcb_local_clnt)
+ rpc_shutdown_client(rpcb_local_clnt);
+}