[RFC v3 2/3] SUNRPC mark user credentials destroyed

@@ -76,6 +76,7 @@ struct rpc_cred {
 #define RPCAUTH_CRED_UPTODATE	1
 #define RPCAUTH_CRED_HASHED	2
 #define RPCAUTH_CRED_NEGATIVE	3
+#define RPCAUTH_CRED_DESTROYED	4
 
 /* rpc_auth au_flags */
 #define RPCAUTH_AUTH_NO_CRKEY_TIMEOUT	0x0001 /* underlying cred has no key timeout */

@@ -136,6 +137,8 @@ struct rpc_authops {
 						struct rpcsec_gss_info *);
 	int			(*key_timeout)(struct rpc_auth *,
 						struct rpc_cred *);
+	int			(*key_destroy)(struct rpc_auth *,
+						struct rpc_cred *);
 };
 
 struct rpc_credops {

@@ -198,6 +201,8 @@ int			rpcauth_get_gssinfo(rpc_authflavor_t,
 void			rpcauth_clear_credcache(struct rpc_cred_cache *);
 int			rpcauth_key_timeout_notify(struct rpc_auth *,
 						struct rpc_cred *);
+int			rpcauth_key_set_destroy(struct rpc_auth *,
+						struct rpc_cred *);
 bool			rpcauth_cred_key_to_expire(struct rpc_auth *, struct rpc_cred *);
 char *			rpcauth_stringify_acceptor(struct rpc_cred *);
 

@@ -357,6 +357,15 @@ struct rpc_auth *
 }
 EXPORT_SYMBOL_GPL(rpcauth_key_timeout_notify);
 
+int
+rpcauth_key_set_destroy(struct rpc_auth *auth, struct rpc_cred *cred)
+{
+	if (!cred->cr_auth->au_ops->key_destroy)
+		return 0;
+	return cred->cr_auth->au_ops->key_destroy(auth, cred);
+}
+EXPORT_SYMBOL_GPL(rpcauth_key_set_destroy);
+
 bool
 rpcauth_cred_key_to_expire(struct rpc_auth *auth, struct rpc_cred *cred)
 {

@@ -263,6 +263,20 @@ void rpc_destroy_generic_auth(void)
 	return ret;
 }
 
+static int
+generic_key_destroy(struct rpc_auth *auth, struct rpc_cred *cred)
+{
+	struct auth_cred *acred = &container_of(cred, struct generic_cred,
+						gc_base)->acred;
+	struct rpc_cred *tcred;
+
+	tcred = auth->au_ops->lookup_cred(auth, acred, 0);
+	if (IS_ERR(tcred))
+		return -ENOENT;
+	set_bit(RPCAUTH_CRED_DESTROYED, &tcred->cr_flags);
+	return 0;
+}
+
 static const struct rpc_authops generic_auth_ops = {
 	.owner = THIS_MODULE,
 	.au_name = "Generic",

@@ -270,6 +284,7 @@ void rpc_destroy_generic_auth(void)
 	.lookup_cred = generic_lookup_cred,
 	.crcreate = generic_create_cred,
 	.key_timeout = generic_key_timeout,
+	.key_destroy = generic_key_destroy,
 };
 
 static struct rpc_auth generic_auth = {

@@ -1473,6 +1473,9 @@ static void gss_pipe_free(struct gss_pipe *p)
 	if (ret == 0)
 		return ret;
 
+	if (test_bit(RPCAUTH_CRED_DESTROYED, &rc->cr_flags))
+		return 0;
+
 	/* Notify acred users of GSS context expiration timeout */
 	if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags) &&
 	    (gss_key_timeout(rc) != 0)) {