/* * fs/sdcardfs/multiuser.h * * Copyright (c) 2013 Samsung Electronics Co. Ltd * Authors: Daeho Jeong, Woojoong Lee, Seunghwan Hyun, * Sunghwan Yun, Sungjong Seo * * This program has been developed as a stackable file system based on * the WrapFS which written by * * Copyright (c) 1998-2011 Erez Zadok * Copyright (c) 2009 Shrikar Archak * Copyright (c) 2003-2011 Stony Brook University * Copyright (c) 2003-2011 The Research Foundation of SUNY * * This file is dual licensed. It may be redistributed and/or modified * under the terms of the Apache 2.0 License OR version 2 of the GNU * General Public License. */ #define MULTIUSER_APP_PER_USER_RANGE 100000 typedef uid_t userid_t; typedef uid_t appid_t; static inline userid_t multiuser_get_user_id(uid_t uid) { return uid / MULTIUSER_APP_PER_USER_RANGE; } static inline appid_t multiuser_get_app_id(uid_t uid) { return uid % MULTIUSER_APP_PER_USER_RANGE; } static inline uid_t multiuser_get_uid(userid_t userId, appid_t appId) { return userId * MULTIUSER_APP_PER_USER_RANGE + (appId % MULTIUSER_APP_PER_USER_RANGE); }