[PATCH] RPC: [PATCH] improve rpcauthauth_create error returns

 Currently we return -ENOMEM for every single failure to create a new auth.
 This is actually accurate for auth_null and auth_unix, but for auth_gss it's a
 bit confusing.

 Allow rpcauth_create (and the ->create methods) to return errors.  With this
 patch, the user may sometimes see an EINVAL instead.  Whee.

 Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index 9bcec9b..505e2d4 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -66,10 +66,10 @@
 	u32			flavor = pseudoflavor_to_flavor(pseudoflavor);
 
 	if (flavor >= RPC_AUTH_MAXFLAVOR || !(ops = auth_flavors[flavor]))
-		return NULL;
+		return ERR_PTR(-EINVAL);
 	auth = ops->create(clnt, pseudoflavor);
-	if (!auth)
-		return NULL;
+	if (IS_ERR(auth))
+		return auth;
 	if (clnt->cl_auth)
 		rpcauth_destroy(clnt->cl_auth);
 	clnt->cl_auth = auth;
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 7d88db8..2f7b867 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -660,14 +660,16 @@
 {
 	struct gss_auth *gss_auth;
 	struct rpc_auth * auth;
+	int err = -ENOMEM; /* XXX? */
 
 	dprintk("RPC:      creating GSS authenticator for client %p\n",clnt);
 
 	if (!try_module_get(THIS_MODULE))
-		return NULL;
+		return ERR_PTR(err);
 	if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 		goto out_dec;
 	gss_auth->client = clnt;
+	err = -EINVAL;
 	gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 	if (!gss_auth->mech) {
 		printk(KERN_WARNING "%s: Pseudoflavor %d not found!",
@@ -686,15 +688,18 @@
 	auth->au_flavor = flavor;
 	atomic_set(&auth->au_count, 1);
 
-	if (rpcauth_init_credcache(auth, GSS_CRED_EXPIRE) < 0)
+	err = rpcauth_init_credcache(auth, GSS_CRED_EXPIRE);
+	if (err)
 		goto err_put_mech;
 
 	snprintf(gss_auth->path, sizeof(gss_auth->path), "%s/%s",
 			clnt->cl_pathname,
 			gss_auth->mech->gm_name);
 	gss_auth->dentry = rpc_mkpipe(gss_auth->path, clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
-	if (IS_ERR(gss_auth->dentry))
+	if (IS_ERR(gss_auth->dentry)) {
+		err = PTR_ERR(gss_auth->dentry);
 		goto err_put_mech;
+	}
 
 	return auth;
 err_put_mech:
@@ -703,7 +708,7 @@
 	kfree(gss_auth);
 out_dec:
 	module_put(THIS_MODULE);
-	return NULL;
+	return ERR_PTR(err);
 }
 
 static void
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index b36797a..9da1deb 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -103,6 +103,7 @@
 {
 	struct rpc_version	*version;
 	struct rpc_clnt		*clnt = NULL;
+	struct rpc_auth		*auth;
 	int err;
 	int len;
 
@@ -157,10 +158,11 @@
 	if (err < 0)
 		goto out_no_path;
 
-	err = -ENOMEM;
-	if (!rpcauth_create(flavor, clnt)) {
+	auth = rpcauth_create(flavor, clnt);
+	if (IS_ERR(auth)) {
 		printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 				flavor);
+		err = PTR_ERR(auth);
 		goto out_no_auth;
 	}