NSM: Generate NSMPROC_MON's "priv" argument when nsm_handle is created

Introduce a new data type, used by both the in-kernel NLM and NSM
implementations, that is used to manage the opaque "priv" argument
for the NSMPROC_MON and NLMPROC_SM_NOTIFY calls.

Construct the "priv" cookie when the nsm_handle is created.

The nsm_init_private() function may look a little strange, but it is
roughly equivalent to how the XDR encoder formed the "priv" argument.
It's going to go away soon.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

fs/lockd/mon.c

@@ -201,6 +201,21 @@ void nsm_unmonitor(const struct nlm_host *host)
 	}
 }
 
+/*
+ * Construct a unique cookie to match this nsm_handle to this monitored
+ * host.  It is passed to the local rpc.statd via NSMPROC_MON, and
+ * returned via NLMPROC_SM_NOTIFY, in the "priv" field of these
+ * requests.
+ *
+ * Linux provides the raw IP address of the monitored host,
+ * left in network byte order.
+ */
+static void nsm_init_private(struct nsm_handle *nsm)
+{
+	__be32 *p = (__be32 *)&nsm->sm_priv.data;
+	*p = nsm_addr_in(nsm)->sin_addr.s_addr;
+}
+
 /**
  * nsm_find - Find or create a cached nsm_handle
  * @sap: pointer to socket address of handle to find
@@ -271,6 +286,7 @@ struct nsm_handle *nsm_find(const struct sockaddr *sap, const size_t salen,
 	nsm->sm_name = (char *) (nsm + 1);
 	memcpy(nsm->sm_name, hostname, hostname_len);
 	nsm->sm_name[hostname_len] = '\0';
+	nsm_init_private(nsm);
 	nsm_display_address((struct sockaddr *)&nsm->sm_addr,
 				nsm->sm_addrbuf, sizeof(nsm->sm_addrbuf));
 	atomic_set(&nsm->sm_count, 1);

include/linux/lockd/lockd.h

@@ -85,6 +85,7 @@ struct nsm_handle {
 	size_t			sm_addrlen;
 	unsigned int		sm_monitored : 1,
 				sm_sticky : 1;	/* don't unmonitor */
+	struct nsm_private	sm_priv;
 	char			sm_addrbuf[NSM_ADDRBUF];
 };
 

include/linux/lockd/sm_inter.h

@@ -10,7 +10,6 @@
 #define LINUX_LOCKD_SM_INTER_H
 
 #define SM_MAXSTRLEN	1024
-#define SM_PRIV_SIZE	16
 
 extern int	nsm_local_state;
 

include/linux/lockd/xdr.h

@@ -13,6 +13,12 @@
 #include <linux/nfs.h>
 #include <linux/sunrpc/xdr.h>
 
+#define SM_PRIV_SIZE		16
+
+struct nsm_private {
+	unsigned char		data[SM_PRIV_SIZE];
+};
+
 struct svc_rqst;
 
 #define NLM_MAXCOOKIELEN    	32