SUNRPC: Add enum svc_auth_status

In addition to the benefits of using an enum rather than a set of
macros, we now have a named type that can improve static type
checking of function return values.

As part of this change, I removed a stale comment from svcauth.h;
the return values from current implementations of the
auth_ops::release method are all zero/negative errno, not the SVC_OK
enum values as the old comment suggested.

Suggested-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

3 files changed, 31 insertions, 30 deletions

diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 9b429253dbd9..1c491f02efc8 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -336,7 +336,7 @@ struct svc_program {
 	char *			pg_name;	/* service name */
 	char *			pg_class;	/* class name: services sharing authentication */
 	struct svc_stat *	pg_stats;	/* rpc statistics */
-	int			(*pg_authenticate)(struct svc_rqst *);
+	enum svc_auth_status	(*pg_authenticate)(struct svc_rqst *rqstp);
 	__be32			(*pg_init_request)(struct svc_rqst *,
 						   const struct svc_program *,
 						   struct svc_process_info *);
diff --git a/include/linux/sunrpc/svcauth.h b/include/linux/sunrpc/svcauth.h
index 27582d3b538f..6f90203edbf8 100644
--- a/include/linux/sunrpc/svcauth.h
+++ b/include/linux/sunrpc/svcauth.h
@@ -83,6 +83,19 @@ struct auth_domain {
 	struct rcu_head		rcu_head;
 };
 
+enum svc_auth_status {
+	SVC_GARBAGE = 1,
+	SVC_SYSERR,
+	SVC_VALID,
+	SVC_NEGATIVE,
+	SVC_OK,
+	SVC_DROP,
+	SVC_CLOSE,
+	SVC_DENIED,
+	SVC_PENDING,
+	SVC_COMPLETE,
+};
+
 /*
  * Each authentication flavour registers an auth_ops
  * structure.
@@ -98,6 +111,8 @@ struct auth_domain {
  *             is (probably) already in place.  Certainly space is
  *	       reserved for it.
  *      DROP - simply drop the request. It may have been deferred
+ *      CLOSE - like SVC_DROP, but request is definitely lost.
+ *		If there is a tcp connection, it should be closed.
  *      GARBAGE - rpc garbage_args error
  *      SYSERR - rpc system_err error
  *      DENIED - authp holds reason for denial.
@@ -111,14 +126,10 @@ struct auth_domain {
  *
  * release() is given a request after the procedure has been run.
  *  It should sign/encrypt the results if needed
- * It should return:
- *    OK - the resbuf is ready to be sent
- *    DROP - the reply should be quitely dropped
- *    DENIED - authp holds a reason for MSG_DENIED
- *    SYSERR - rpc system_err
  *
  * domain_release()
  *   This call releases a domain.
+ *
  * set_client()
  *   Givens a pending request (struct svc_rqst), finds and assigns
  *   an appropriate 'auth_domain' as the client.
@@ -127,31 +138,18 @@ struct auth_ops {
 	char *	name;
 	struct module *owner;
 	int	flavour;
-	int	(*accept)(struct svc_rqst *rq);
-	int	(*release)(struct svc_rqst *rq);
-	void	(*domain_release)(struct auth_domain *);
-	int	(*set_client)(struct svc_rqst *rq);
-};
 
-#define	SVC_GARBAGE	1
-#define	SVC_SYSERR	2
-#define	SVC_VALID	3
-#define	SVC_NEGATIVE	4
-#define	SVC_OK		5
-#define	SVC_DROP	6
-#define	SVC_CLOSE	7	/* Like SVC_DROP, but request is definitely
-				 * lost so if there is a tcp connection, it
-				 * should be closed
-				 */
-#define	SVC_DENIED	8
-#define	SVC_PENDING	9
-#define	SVC_COMPLETE	10
+	enum svc_auth_status	(*accept)(struct svc_rqst *rqstp);
+	int			(*release)(struct svc_rqst *rqstp);
+	void			(*domain_release)(struct auth_domain *dom);
+	enum svc_auth_status	(*set_client)(struct svc_rqst *rqstp);
+};
 
 struct svc_xprt;
 
-extern int	svc_authenticate(struct svc_rqst *rqstp);
+extern enum svc_auth_status svc_authenticate(struct svc_rqst *rqstp);
 extern int	svc_authorise(struct svc_rqst *rqstp);
-extern int	svc_set_client(struct svc_rqst *rqstp);
+extern enum svc_auth_status svc_set_client(struct svc_rqst *rqstp);
 extern int	svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops);
 extern void	svc_auth_unregister(rpc_authflavor_t flavor);
 
@@ -161,7 +159,7 @@ extern struct auth_domain *auth_domain_lookup(char *name, struct auth_domain *ne
 extern struct auth_domain *auth_domain_find(char *name);
 extern void svcauth_unix_purge(struct net *net);
 extern void svcauth_unix_info_release(struct svc_xprt *xpt);
-extern int svcauth_unix_set_client(struct svc_rqst *rqstp);
+extern enum svc_auth_status svcauth_unix_set_client(struct svc_rqst *rqstp);
 
 extern int unix_gid_cache_create(struct net *net);
 extern void unix_gid_cache_destroy(struct net *net);
diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h
index 00db9e1fb711..55716b62ce91 100644
--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h
@@ -1706,7 +1706,7 @@ TRACE_DEFINE_ENUM(SVC_DENIED);
 TRACE_DEFINE_ENUM(SVC_PENDING);
 TRACE_DEFINE_ENUM(SVC_COMPLETE);
 
-#define svc_show_status(status)				\
+#define show_svc_auth_status(status)			\
 	__print_symbolic(status,			\
 		{ SVC_GARBAGE,	"SVC_GARBAGE" },	\
 		{ SVC_SYSERR,	"SVC_SYSERR" },		\
@@ -1743,7 +1743,10 @@ TRACE_DEFINE_ENUM(SVC_COMPLETE);
 		__entry->xid, __get_sockaddr(server), __get_sockaddr(client)
 
 TRACE_EVENT_CONDITION(svc_authenticate,
-	TP_PROTO(const struct svc_rqst *rqst, int auth_res),
+	TP_PROTO(
+		const struct svc_rqst *rqst,
+		enum svc_auth_status auth_res
+	),
 
 	TP_ARGS(rqst, auth_res),
 
@@ -1766,7 +1769,7 @@ TRACE_EVENT_CONDITION(svc_authenticate,
 	TP_printk(SVC_RQST_ENDPOINT_FORMAT
 		" auth_res=%s auth_stat=%s",
 		SVC_RQST_ENDPOINT_VARARGS,
-		svc_show_status(__entry->svc_status),
+		show_svc_auth_status(__entry->svc_status),
 		rpc_show_auth_stat(__entry->auth_stat))
 );