SUNRPC: Ensure that rpc_mkpipe returns a refcounted dentry

If not, we cannot guarantee that idmap->idmap_dentry, gss_auth->dentry and
clnt->cl_dentry are valid dentries.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/idmap.c

@@ -132,6 +132,8 @@ nfs_idmap_delete(struct nfs4_client *clp)
 
 	if (!idmap)
 		return;
+	dput(idmap->idmap_dentry);
+	idmap->idmap_dentry = NULL;
 	rpc_unlink(idmap->idmap_path);
 	clp->cl_idmap = NULL;
 	kfree(idmap);

net/sunrpc/auth_gss/auth_gss.c

@@ -721,6 +721,8 @@ gss_destroy(struct rpc_auth *auth)
 
 	gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 	rpc_unlink(gss_auth->path);
+	dput(gss_auth->dentry);
+	gss_auth->dentry = NULL;
 	gss_mech_put(gss_auth->mech);
 
 	rpcauth_free_credcache(auth);

net/sunrpc/clnt.c

@@ -240,6 +240,7 @@ rpc_clone_client(struct rpc_clnt *clnt)
 	new->cl_autobind = 0;
 	new->cl_oneshot = 0;
 	new->cl_dead = 0;
+	dget(new->cl_dentry);
 	rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
 	if (new->cl_auth)
 		atomic_inc(&new->cl_auth->au_count);
@@ -314,6 +315,8 @@ rpc_destroy_client(struct rpc_clnt *clnt)
 	if (clnt->cl_server != clnt->cl_inline_name)
 		kfree(clnt->cl_server);
 out_free:
+	if (clnt->cl_dentry)
+		dput(clnt->cl_dentry);
 	kfree(clnt);
 	return 0;
 }

net/sunrpc/rpc_pipe.c

@@ -669,7 +669,7 @@ rpc_mkdir(char *path, struct rpc_clnt *rpc_client)
 out:
 	mutex_unlock(&dir->i_mutex);
 	rpc_release_path(&nd);
-	return dentry;
+	return dget(dentry);
 err_depopulate:
 	rpc_depopulate(dentry);
 	__rpc_rmdir(dir, dentry);
@@ -733,7 +733,7 @@ rpc_mkpipe(char *path, void *private, struct rpc_pipe_ops *ops, int flags)
 out:
 	mutex_unlock(&dir->i_mutex);
 	rpc_release_path(&nd);
-	return dentry;
+	return dget(dentry);
 err_dput:
 	dput(dentry);
 	dentry = ERR_PTR(-ENOMEM);