NLM: Move the public declaration of nsm_monitor() to lockd.h

Clean up.

Make the nlm_host argument "const," and move the public declaration to
lockd.h with other NSM public function (nsm_release, eg) and global
variable declarations.

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

fs/lockd/mon.c

@@ -69,11 +69,18 @@ nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res)
 	return status;
 }
 
-/*
- * Set up monitoring of a remote host
+/**
+ * nsm_monitor - Notify a peer in case we reboot
+ * @host: pointer to nlm_host of peer to notify
+ *
+ * If this peer is not already monitored, this function sends an
+ * upcall to the local rpc.statd to record the name/address of
+ * the peer to notify in case we reboot.
+ *
+ * Returns zero if the peer is monitored by the local rpc.statd;
+ * otherwise a negative errno value is returned.
  */
-int
-nsm_monitor(struct nlm_host *host)
+int nsm_monitor(const struct nlm_host *host)
 {
 	struct nsm_handle *nsm = host->h_nsmhandle;
 	struct nsm_res	res;

include/linux/lockd/lockd.h

@@ -242,6 +242,10 @@ extern void	  nlm_host_rebooted(const struct sockaddr_in *, const char *,
 					unsigned int, u32);
 void		  nsm_release(struct nsm_handle *);
 
+/*
+ * Host monitoring
+ */
+int		  nsm_monitor(const struct nlm_host *host);
 
 /*
  * This is used in garbage collection and resource reclaim

include/linux/lockd/sm_inter.h

@@ -41,7 +41,6 @@ struct nsm_res {
 	u32		state;
 };
 
-int		nsm_monitor(struct nlm_host *);
 int		nsm_unmonitor(struct nlm_host *);
 extern int	nsm_local_state;