| /* |
| * fs/sdcardfs/sdcardfs.h |
| * |
| * The sdcardfs v2.0 |
| * This file system replaces the sdcard daemon on Android |
| * On version 2.0, some of the daemon functions have been ported |
| * to support the multi-user concepts of Android 4.4 |
| * |
| * 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. |
| */ |
| |
| #ifndef _SDCARDFS_H_ |
| #define _SDCARDFS_H_ |
| |
| #include <linux/dcache.h> |
| #include <linux/file.h> |
| #include <linux/fs.h> |
| #include <linux/mm.h> |
| #include <linux/mount.h> |
| #include <linux/namei.h> |
| #include <linux/seq_file.h> |
| #include <linux/statfs.h> |
| #include <linux/fs_stack.h> |
| #include <linux/magic.h> |
| #include <linux/uaccess.h> |
| #include <linux/slab.h> |
| #include <linux/sched.h> |
| #include <linux/types.h> |
| #include <linux/security.h> |
| #include <linux/string.h> |
| #include "multiuser.h" |
| |
| /* the file system name */ |
| #define SDCARDFS_NAME "sdcardfs" |
| |
| /* sdcardfs root inode number */ |
| #define SDCARDFS_ROOT_INO 1 |
| |
| /* useful for tracking code reachability */ |
| #define UDBG printk(KERN_DEFAULT "DBG:%s:%s:%d\n", __FILE__, __func__, __LINE__) |
| |
| #define SDCARDFS_DIRENT_SIZE 256 |
| |
| /* temporary static uid settings for development */ |
| #define AID_ROOT 0 /* uid for accessing /mnt/sdcard & extSdcard */ |
| #define AID_MEDIA_RW 1023 /* internal media storage write access */ |
| |
| #define AID_SDCARD_RW 1015 /* external storage write access */ |
| #define AID_SDCARD_R 1028 /* external storage read access */ |
| #define AID_SDCARD_PICS 1033 /* external storage photos access */ |
| #define AID_SDCARD_AV 1034 /* external storage audio/video access */ |
| #define AID_SDCARD_ALL 1035 /* access all users external storage */ |
| |
| #define AID_PACKAGE_INFO 1027 |
| |
| #define fix_derived_permission(x) \ |
| do { \ |
| (x)->i_uid = SDCARDFS_I(x)->d_uid; \ |
| (x)->i_gid = SDCARDFS_I(x)->d_gid; \ |
| (x)->i_mode = ((x)->i_mode & S_IFMT) | SDCARDFS_I(x)->d_mode;\ |
| } while (0) |
| |
| /* OVERRIDE_CRED() and REVERT_CRED() |
| * OVERRID_CRED() |
| * backup original task->cred |
| * and modifies task->cred->fsuid/fsgid to specified value. |
| * REVERT_CRED() |
| * restore original task->cred->fsuid/fsgid. |
| * These two macro should be used in pair, and OVERRIDE_CRED() should be |
| * placed at the beginning of a function, right after variable declaration. |
| */ |
| #define OVERRIDE_CRED(sdcardfs_sbi, saved_cred) \ |
| saved_cred = override_fsids(sdcardfs_sbi); \ |
| if (!saved_cred) { return -ENOMEM; } |
| |
| #define OVERRIDE_CRED_PTR(sdcardfs_sbi, saved_cred) \ |
| saved_cred = override_fsids(sdcardfs_sbi); \ |
| if (!saved_cred) { return ERR_PTR(-ENOMEM); } |
| |
| #define REVERT_CRED(saved_cred) revert_fsids(saved_cred) |
| |
| #define DEBUG_CRED() \ |
| printk("KAKJAGI: %s:%d fsuid %d fsgid %d\n", \ |
| __FUNCTION__, __LINE__, \ |
| (int)current->cred->fsuid, \ |
| (int)current->cred->fsgid); |
| |
| /* Android 4.4 support */ |
| |
| /* Permission mode for a specific node. Controls how file permissions |
| * are derived for children nodes. */ |
| typedef enum { |
| /* Nothing special; this node should just inherit from its parent. */ |
| PERM_INHERIT, |
| /* This node is one level above a normal root; used for legacy layouts |
| * which use the first level to represent user_id. */ |
| PERM_LEGACY_PRE_ROOT, |
| /* This node is "/" */ |
| PERM_ROOT, |
| /* This node is "/Android" */ |
| PERM_ANDROID, |
| /* This node is "/Android/data" */ |
| PERM_ANDROID_DATA, |
| /* This node is "/Android/obb" */ |
| PERM_ANDROID_OBB, |
| /* This node is "/Android/user" */ |
| PERM_ANDROID_USER, |
| } perm_t; |
| |
| /* Permissions structure to derive */ |
| typedef enum { |
| DERIVE_NONE, |
| DERIVE_LEGACY, |
| DERIVE_UNIFIED, |
| } derive_t; |
| |
| typedef enum { |
| LOWER_FS_EXT4, |
| LOWER_FS_FAT, |
| } lower_fs_t; |
| |
| struct sdcardfs_sb_info; |
| struct sdcardfs_mount_options; |
| |
| /* Do not directly use this function. Use OVERRIDE_CRED() instead. */ |
| const struct cred * override_fsids(struct sdcardfs_sb_info* sbi); |
| /* Do not directly use this function, use REVERT_CRED() instead. */ |
| void revert_fsids(const struct cred * old_cred); |
| |
| /* operations vectors defined in specific files */ |
| extern const struct file_operations sdcardfs_main_fops; |
| extern const struct file_operations sdcardfs_dir_fops; |
| extern const struct inode_operations sdcardfs_main_iops; |
| extern const struct inode_operations sdcardfs_dir_iops; |
| extern const struct inode_operations sdcardfs_symlink_iops; |
| extern const struct super_operations sdcardfs_sops; |
| extern const struct dentry_operations sdcardfs_ci_dops; |
| extern const struct address_space_operations sdcardfs_aops, sdcardfs_dummy_aops; |
| extern const struct vm_operations_struct sdcardfs_vm_ops; |
| |
| extern int sdcardfs_init_inode_cache(void); |
| extern void sdcardfs_destroy_inode_cache(void); |
| extern int sdcardfs_init_dentry_cache(void); |
| extern void sdcardfs_destroy_dentry_cache(void); |
| extern int new_dentry_private_data(struct dentry *dentry); |
| extern void free_dentry_private_data(struct dentry *dentry); |
| extern struct dentry *sdcardfs_lookup(struct inode *dir, struct dentry *dentry, |
| struct nameidata *nd); |
| extern struct inode *sdcardfs_iget(struct super_block *sb, |
| struct inode *lower_inode); |
| extern int sdcardfs_interpose(struct dentry *dentry, struct super_block *sb, |
| struct path *lower_path); |
| |
| /* file private data */ |
| struct sdcardfs_file_info { |
| struct file *lower_file; |
| const struct vm_operations_struct *lower_vm_ops; |
| }; |
| |
| /* sdcardfs inode data in memory */ |
| struct sdcardfs_inode_info { |
| struct inode *lower_inode; |
| /* state derived based on current position in hierachy |
| * caution: d_mode does not include file types |
| */ |
| perm_t perm; |
| userid_t userid; |
| uid_t d_uid; |
| gid_t d_gid; |
| mode_t d_mode; |
| |
| struct inode vfs_inode; |
| }; |
| |
| /* sdcardfs dentry data in memory */ |
| struct sdcardfs_dentry_info { |
| spinlock_t lock; /* protects lower_path */ |
| struct path lower_path; |
| struct path orig_path; |
| }; |
| |
| struct sdcardfs_mount_options { |
| uid_t fs_low_uid; |
| gid_t fs_low_gid; |
| gid_t write_gid; |
| int split_perms; |
| derive_t derive; |
| lower_fs_t lower_fs; |
| unsigned int reserved_mb; |
| }; |
| |
| /* sdcardfs super-block data in memory */ |
| struct sdcardfs_sb_info { |
| struct super_block *lower_sb; |
| /* derived perm policy : some of options have been added |
| * to sdcardfs_mount_options (Android 4.4 support) */ |
| struct sdcardfs_mount_options options; |
| spinlock_t lock; /* protects obbpath */ |
| char *obbpath_s; |
| struct path obbpath; |
| void *pkgl_id; |
| }; |
| |
| /* |
| * inode to private data |
| * |
| * Since we use containers and the struct inode is _inside_ the |
| * sdcardfs_inode_info structure, SDCARDFS_I will always (given a non-NULL |
| * inode pointer), return a valid non-NULL pointer. |
| */ |
| static inline struct sdcardfs_inode_info *SDCARDFS_I(const struct inode *inode) |
| { |
| return container_of(inode, struct sdcardfs_inode_info, vfs_inode); |
| } |
| |
| /* dentry to private data */ |
| #define SDCARDFS_D(dent) ((struct sdcardfs_dentry_info *)(dent)->d_fsdata) |
| |
| /* superblock to private data */ |
| #define SDCARDFS_SB(super) ((struct sdcardfs_sb_info *)(super)->s_fs_info) |
| |
| /* file to private Data */ |
| #define SDCARDFS_F(file) ((struct sdcardfs_file_info *)((file)->private_data)) |
| |
| /* file to lower file */ |
| static inline struct file *sdcardfs_lower_file(const struct file *f) |
| { |
| return SDCARDFS_F(f)->lower_file; |
| } |
| |
| static inline void sdcardfs_set_lower_file(struct file *f, struct file *val) |
| { |
| SDCARDFS_F(f)->lower_file = val; |
| } |
| |
| /* inode to lower inode. */ |
| static inline struct inode *sdcardfs_lower_inode(const struct inode *i) |
| { |
| return SDCARDFS_I(i)->lower_inode; |
| } |
| |
| static inline void sdcardfs_set_lower_inode(struct inode *i, struct inode *val) |
| { |
| SDCARDFS_I(i)->lower_inode = val; |
| } |
| |
| /* superblock to lower superblock */ |
| static inline struct super_block *sdcardfs_lower_super( |
| const struct super_block *sb) |
| { |
| return SDCARDFS_SB(sb)->lower_sb; |
| } |
| |
| static inline void sdcardfs_set_lower_super(struct super_block *sb, |
| struct super_block *val) |
| { |
| SDCARDFS_SB(sb)->lower_sb = val; |
| } |
| |
| /* path based (dentry/mnt) macros */ |
| static inline void pathcpy(struct path *dst, const struct path *src) |
| { |
| dst->dentry = src->dentry; |
| dst->mnt = src->mnt; |
| } |
| |
| /* sdcardfs_get_pname functions calls path_get() |
| * therefore, the caller must call "proper" path_put functions |
| */ |
| #define SDCARDFS_DENT_FUNC(pname) \ |
| static inline void sdcardfs_get_##pname(const struct dentry *dent, \ |
| struct path *pname) \ |
| { \ |
| spin_lock(&SDCARDFS_D(dent)->lock); \ |
| pathcpy(pname, &SDCARDFS_D(dent)->pname); \ |
| path_get(pname); \ |
| spin_unlock(&SDCARDFS_D(dent)->lock); \ |
| return; \ |
| } \ |
| static inline void sdcardfs_put_##pname(const struct dentry *dent, \ |
| struct path *pname) \ |
| { \ |
| path_put(pname); \ |
| return; \ |
| } \ |
| static inline void sdcardfs_set_##pname(const struct dentry *dent, \ |
| struct path *pname) \ |
| { \ |
| spin_lock(&SDCARDFS_D(dent)->lock); \ |
| pathcpy(&SDCARDFS_D(dent)->pname, pname); \ |
| spin_unlock(&SDCARDFS_D(dent)->lock); \ |
| return; \ |
| } \ |
| static inline void sdcardfs_reset_##pname(const struct dentry *dent) \ |
| { \ |
| spin_lock(&SDCARDFS_D(dent)->lock); \ |
| SDCARDFS_D(dent)->pname.dentry = NULL; \ |
| SDCARDFS_D(dent)->pname.mnt = NULL; \ |
| spin_unlock(&SDCARDFS_D(dent)->lock); \ |
| return; \ |
| } \ |
| static inline void sdcardfs_put_reset_##pname(const struct dentry *dent) \ |
| { \ |
| struct path pname; \ |
| spin_lock(&SDCARDFS_D(dent)->lock); \ |
| if(SDCARDFS_D(dent)->pname.dentry) { \ |
| pathcpy(&pname, &SDCARDFS_D(dent)->pname); \ |
| SDCARDFS_D(dent)->pname.dentry = NULL; \ |
| SDCARDFS_D(dent)->pname.mnt = NULL; \ |
| spin_unlock(&SDCARDFS_D(dent)->lock); \ |
| path_put(&pname); \ |
| } else \ |
| spin_unlock(&SDCARDFS_D(dent)->lock); \ |
| return; \ |
| } |
| |
| SDCARDFS_DENT_FUNC(lower_path) |
| SDCARDFS_DENT_FUNC(orig_path) |
| |
| static inline int has_graft_path(const struct dentry *dent) |
| { |
| int ret = 0; |
| |
| spin_lock(&SDCARDFS_D(dent)->lock); |
| if (SDCARDFS_D(dent)->orig_path.dentry != NULL) |
| ret = 1; |
| spin_unlock(&SDCARDFS_D(dent)->lock); |
| |
| return ret; |
| } |
| |
| static inline void sdcardfs_get_real_lower(const struct dentry *dent, |
| struct path *real_lower) |
| { |
| /* in case of a local obb dentry |
| * the orig_path should be returned |
| */ |
| if(has_graft_path(dent)) |
| sdcardfs_get_orig_path(dent, real_lower); |
| else |
| sdcardfs_get_lower_path(dent, real_lower); |
| } |
| |
| static inline void sdcardfs_put_real_lower(const struct dentry *dent, |
| struct path *real_lower) |
| { |
| if(has_graft_path(dent)) |
| sdcardfs_put_orig_path(dent, real_lower); |
| else |
| sdcardfs_put_lower_path(dent, real_lower); |
| } |
| |
| /* for packagelist.c */ |
| extern int get_caller_has_rw_locked(void *pkgl_id, derive_t derive); |
| extern appid_t get_appid(void *pkgl_id, const char *app_name); |
| extern int check_caller_access_to_name(struct inode *parent_node, const char* name, |
| derive_t derive, int w_ok, int has_rw); |
| extern int open_flags_to_access_mode(int open_flags); |
| extern void * packagelist_create(gid_t write_gid); |
| extern void packagelist_destroy(void *pkgl_id); |
| extern int packagelist_init(void); |
| extern void packagelist_exit(void); |
| |
| /* for derived_perm.c */ |
| extern void setup_derived_state(struct inode *inode, perm_t perm, |
| userid_t userid, uid_t uid, gid_t gid, mode_t mode); |
| extern void get_derived_permission(struct dentry *parent, struct dentry *dentry); |
| extern void update_derived_permission(struct dentry *dentry); |
| extern int need_graft_path(struct dentry *dentry); |
| extern int is_base_obbpath(struct dentry *dentry); |
| extern int is_obbpath_invalid(struct dentry *dentry); |
| extern int setup_obb_dentry(struct dentry *dentry, struct path *lower_path); |
| |
| /* locking helpers */ |
| static inline struct dentry *lock_parent(struct dentry *dentry) |
| { |
| struct dentry *dir = dget_parent(dentry); |
| mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT); |
| return dir; |
| } |
| |
| static inline void unlock_dir(struct dentry *dir) |
| { |
| mutex_unlock(&dir->d_inode->i_mutex); |
| dput(dir); |
| } |
| |
| static inline int prepare_dir(const char *path_s, uid_t uid, gid_t gid, mode_t mode) |
| { |
| int err; |
| struct dentry *dent; |
| struct iattr attrs; |
| struct path parent; |
| |
| dent = kern_path_locked(path_s, &parent); |
| if (IS_ERR(dent)) { |
| err = PTR_ERR(dent); |
| if (err == -EEXIST) |
| err = 0; |
| goto out_unlock; |
| } |
| |
| err = vfs_mkdir(parent.dentry->d_inode, dent, mode); |
| if (err) { |
| if (err == -EEXIST) |
| err = 0; |
| goto out_dput; |
| } |
| |
| attrs.ia_uid = uid; |
| attrs.ia_gid = gid; |
| attrs.ia_valid = ATTR_UID | ATTR_GID; |
| mutex_lock(&dent->d_inode->i_mutex); |
| notify_change(dent, &attrs); |
| mutex_unlock(&dent->d_inode->i_mutex); |
| |
| out_dput: |
| dput(dent); |
| |
| out_unlock: |
| /* parent dentry locked by lookup_create */ |
| mutex_unlock(&parent.dentry->d_inode->i_mutex); |
| path_put(&parent); |
| |
| return err; |
| } |
| |
| /* |
| * Return 1, if a disk has enough free space, otherwise 0. |
| * We assume that any files can not be overwritten. |
| */ |
| static inline int check_min_free_space(struct dentry *dentry, size_t size, int dir) |
| { |
| int err; |
| struct path lower_path; |
| struct kstatfs statfs; |
| u64 avail; |
| struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb); |
| |
| if (sbi->options.reserved_mb) { |
| /* Get fs stat of lower filesystem. */ |
| sdcardfs_get_lower_path(dentry, &lower_path); |
| err = vfs_statfs(&lower_path, &statfs); |
| sdcardfs_put_lower_path(dentry, &lower_path); |
| |
| if (unlikely(err)) |
| return 0; |
| |
| /* Invalid statfs informations. */ |
| if (unlikely(statfs.f_bsize == 0)) |
| return 0; |
| |
| /* if you are checking directory, set size to f_bsize. */ |
| if (unlikely(dir)) |
| size = statfs.f_bsize; |
| |
| /* available size */ |
| avail = statfs.f_bavail * statfs.f_bsize; |
| |
| /* not enough space */ |
| if ((u64)size > avail) |
| return 0; |
| |
| /* enough space */ |
| if ((avail - size) > (sbi->options.reserved_mb * 1024 * 1024)) |
| return 1; |
| |
| return 0; |
| } else |
| return 1; |
| } |
| |
| #endif /* not _SDCARDFS_H_ */ |