android_kernel_samsung_hero.../fs/sdcardfs/multiuser.h
2016-08-17 16:41:52 +08:00

37 lines
1.2 KiB
C

/*
* 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);
}