static int sdcardfskk_unlink(struct inode *dir, struct dentry *dentry)
{
int err;
struct dentry *lower_dentry;
struct inode *lower_dir_inode = sdcardfskk_lower_inode(dir);
struct dentry *lower_dir_dentry;
struct path lower_path;
struct sdcardfskk_sb_info *sbi = SDCARDFSKK_SB(dentry->d_sb);
const struct cred *saved_cred = NULL;
int has_rw = get_caller_has_rw_locked(sbi->pkgl_id, sbi->options.derive);
if(!check_caller_access_to_name(dir, dentry->d_name.name, sbi->options.derive, 1, has_rw)) {
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" dentry: %s, task:%s\n",
__func__, dentry->d_name.name, current->comm);
err = -EACCES;
goto out_eacces;
}
/* save current_cred and override it */
OVERRIDE_CRED(SDCARDFSKK_SB(dir->i_sb), saved_cred);
sdcardfskk_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
dget(lower_dentry);
lower_dir_dentry = lock_parent(lower_dentry);
err = mnt_want_write(lower_path.mnt);
if (err)
goto out_unlock;
err = vfs_unlink(lower_dir_inode, lower_dentry);
/*
* Note: unlinking on top of NFS can cause silly-renamed files.
* Trying to delete such files results in EBUSY from NFS
* below. Silly-renamed files will get deleted by NFS later on, so
* we just need to detect them here and treat such EBUSY errors as
* if the upper file was successfully deleted.
*/
if (err == -EBUSY && lower_dentry->d_flags & DCACHE_NFSFS_RENAMED)
err = 0;
if (err)
goto out;
fsstack_copy_attr_times(dir, lower_dir_inode);
fsstack_copy_inode_size(dir, lower_dir_inode);
dentry->d_inode->i_nlink =
sdcardfskk_lower_inode(dentry->d_inode)->i_nlink;
dentry->d_inode->i_ctime = dir->i_ctime;
d_drop(dentry); /* this is needed, else LTP fails (VFS won't do it) */
out:
mnt_drop_write(lower_path.mnt);
out_unlock:
unlock_dir(lower_dir_dentry);
dput(lower_dentry);
sdcardfskk_put_lower_path(dentry, &lower_path);
REVERT_CRED(saved_cred);
out_eacces:
return err;
}
/*
* On success:
* fills dentry object appropriate values and returns NULL.
* On fail (== error)
* returns error ptr
*
* @dir : Parent inode. It is locked (dir->i_mutex)
* @dentry : Target dentry to lookup. we should set each of fields.
* (dentry->d_name is initialized already)
* @nd : nameidata of parent inode
*/
struct dentry *sdcardfskk_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
struct dentry *ret = NULL, *parent;
struct path lower_parent_path;
int err = 0;
struct sdcardfskk_sb_info *sbi = SDCARDFSKK_SB(dentry->d_sb);
const struct cred *saved_cred = NULL;
parent = dget_parent(dentry);
if(!check_caller_access_to_name_kitkat(parent->d_inode, dentry->d_name.name,
sbi->options.derive, 0, 0)) {
ret = ERR_PTR(-EACCES);
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" dentry: %s, task:%s\n",
__func__, dentry->d_name.name, current->comm);
goto out_err;
}
/* save current_cred and override it */
OVERRIDE_CRED_PTR(SDCARDFSKK_SB(dir->i_sb), saved_cred);
sdcardfskk_get_lower_path(parent, &lower_parent_path);
/* allocate dentry private data. We free it in ->d_release */
err = new_dentry_private_data_kitkat(dentry);
if (err) {
ret = ERR_PTR(err);
goto out;
}
ret = __sdcardfskk_lookup(dentry, nd, &lower_parent_path);
if (IS_ERR(ret))
{
goto out;
}
if (ret)
dentry = ret;
if (dentry->d_inode) {
fsstack_copy_attr_times(dentry->d_inode,
sdcardfskk_lower_inode(dentry->d_inode));
/* get drived permission */
get_derived_permission_kitkat(parent, dentry);
fix_derived_permission(dentry->d_inode);
}
/* update parent directory's atime */
fsstack_copy_attr_atime(parent->d_inode,
sdcardfskk_lower_inode(parent->d_inode));
out:
sdcardfskk_put_lower_path(parent, &lower_parent_path);
REVERT_CRED(saved_cred);
out_err:
dput(parent);
return ret;
}
static int sdcardfskk_create(struct inode *dir, struct dentry *dentry,
int mode, struct nameidata *nd)
{
int err = 0;
struct dentry *lower_dentry;
struct dentry *lower_parent_dentry = NULL;
struct path lower_path, saved_path;
struct sdcardfskk_sb_info *sbi = SDCARDFSKK_SB(dentry->d_sb);
const struct cred *saved_cred = NULL;
int has_rw = get_caller_has_rw_locked(sbi->pkgl_id, sbi->options.derive);
if(!check_caller_access_to_name(dir, dentry->d_name.name, sbi->options.derive, 1, has_rw)) {
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" dentry: %s, task:%s\n",
__func__, dentry->d_name.name, current->comm);
err = -EACCES;
goto out_eacces;
}
/* save current_cred and override it */
OVERRIDE_CRED(SDCARDFSKK_SB(dir->i_sb), saved_cred);
sdcardfskk_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_parent_dentry = lock_parent(lower_dentry);
err = mnt_want_write(lower_path.mnt);
if (err)
goto out_unlock;
pathcpy(&saved_path, &nd->path);
pathcpy(&nd->path, &lower_path);
/* set last 16bytes of mode field to 0664 */
mode = (mode & S_IFMT) | 00664;
err = vfs_create(lower_parent_dentry->d_inode, lower_dentry, mode, nd);
pathcpy(&nd->path, &saved_path);
if (err)
goto out;
err = sdcardfskk_interpose(dentry, dir->i_sb, &lower_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, sdcardfskk_lower_inode(dir));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
out:
mnt_drop_write(lower_path.mnt);
out_unlock:
unlock_dir(lower_parent_dentry);
sdcardfskk_put_lower_path(dentry, &lower_path);
REVERT_CRED(saved_cred);
out_eacces:
return err;
}
static int sdcardfskk_rmdir(struct inode *dir, struct dentry *dentry)
{
struct dentry *lower_dentry;
struct dentry *lower_dir_dentry;
int err;
struct path lower_path;
struct sdcardfskk_sb_info *sbi = SDCARDFSKK_SB(dentry->d_sb);
const struct cred *saved_cred = NULL;
//char *path_s = NULL;
int has_rw = get_caller_has_rw_locked(sbi->pkgl_id, sbi->options.derive);
if(!check_caller_access_to_name(dir, dentry->d_name.name, sbi->options.derive, 1, has_rw)) {
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" dentry: %s, task:%s\n",
__func__, dentry->d_name.name, current->comm);
err = -EACCES;
goto out_eacces;
}
/* save current_cred and override it */
OVERRIDE_CRED(SDCARDFSKK_SB(dir->i_sb), saved_cred);
/* sdcardfskk_get_real_lower(): in case of remove an user's obb dentry
* the dentry on the original path should be deleted. */
sdcardfskk_get_real_lower(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_dir_dentry = lock_parent(lower_dentry);
err = mnt_want_write(lower_path.mnt);
if (err)
goto out_unlock;
err = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
if (err)
goto out;
d_drop(dentry); /* drop our dentry on success (why not VFS's job?) */
if (dentry->d_inode)
clear_nlink(dentry->d_inode);
fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
out:
mnt_drop_write(lower_path.mnt);
out_unlock:
unlock_dir(lower_dir_dentry);
sdcardfskk_put_real_lower(dentry, &lower_path);
REVERT_CRED(saved_cred);
out_eacces:
return err;
}
static int sdcardfskk_mknod(struct inode *dir, struct dentry *dentry, int mode,
dev_t dev)
{
int err = 0;
struct dentry *lower_dentry;
struct dentry *lower_parent_dentry = NULL;
struct path lower_path;
OVERRIDE_CRED(SDCARDFSKK_SB(dir->i_sb));
sdcardfskk_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_parent_dentry = lock_parent(lower_dentry);
err = mnt_want_write(lower_path.mnt);
if (err)
goto out_unlock;
err = vfs_mknod(lower_parent_dentry->d_inode, lower_dentry, mode, dev);
if (err)
goto out;
err = sdcardfskk_interpose(dentry, dir->i_sb, &lower_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, sdcardfskk_lower_inode(dir));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
out:
mnt_drop_write(lower_path.mnt);
out_unlock:
unlock_dir(lower_parent_dentry);
sdcardfskk_put_lower_path(dentry, &lower_path);
REVERT_CRED();
return err;
}
static int sdcardfskk_statfs(struct dentry *dentry, struct kstatfs *buf)
{
int err;
struct path lower_path;
u32 min_blocks;
struct sdcardfskk_sb_info *sbi = SDCARDFSKK_SB(dentry->d_sb);
sdcardfskk_get_lower_path(dentry, &lower_path);
err = vfs_statfs(&lower_path, buf);
sdcardfskk_put_lower_path(dentry, &lower_path);
if (sbi->options.reserved_mb) {
/* Invalid statfs informations. */
if (buf->f_bsize == 0) {
printk(KERN_ERR "Returned block size is zero.\n");
return -EINVAL;
}
min_blocks = ((sbi->options.reserved_mb * 1024 * 1024)/buf->f_bsize);
buf->f_blocks -= min_blocks;
if (buf->f_bavail > min_blocks)
buf->f_bavail -= min_blocks;
else
buf->f_bavail = 0;
/* Make reserved blocks invisiable to media storage */
buf->f_bfree = buf->f_bavail;
}
/* set return buf to our f/s to avoid confusing user-level utils */
buf->f_type = SDCARDFS_SUPER_MAGIC;
return err;
}
/* final actions when unmounting a file system */
static void sdcardfskk_put_super(struct super_block *sb)
{
struct sdcardfskk_sb_info *spd;
struct super_block *s;
spd = SDCARDFSKK_SB(sb);
if (!spd)
return;
printk(KERN_ERR "sdcardfskk: umounted dev_name %s\n",
spd->devpath ? spd->devpath : "");
if(spd->devpath)
kfree(spd->devpath);
if(spd->obbpath_s) {
kfree(spd->obbpath_s);
path_put(&spd->obbpath);
}
/* decrement lower super references */
s = sdcardfskk_lower_super(sb);
sdcardfskk_set_lower_super(sb, NULL);
atomic_dec(&s->s_active);
if(spd->pkgl_id)
packagelist_destroy_kitkat(spd->pkgl_id);
kfree(spd);
sb->s_fs_info = NULL;
}
static int sdcardfskk_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *new_dentry)
{
struct dentry *lower_old_dentry;
struct dentry *lower_new_dentry;
struct dentry *lower_dir_dentry;
u64 file_size_save;
int err;
struct path lower_old_path, lower_new_path;
OVERRIDE_CRED(SDCARDFSKK_SB(dir->i_sb));
file_size_save = i_size_read(old_dentry->d_inode);
sdcardfskk_get_lower_path(old_dentry, &lower_old_path);
sdcardfskk_get_lower_path(new_dentry, &lower_new_path);
lower_old_dentry = lower_old_path.dentry;
lower_new_dentry = lower_new_path.dentry;
lower_dir_dentry = lock_parent(lower_new_dentry);
err = mnt_want_write(lower_new_path.mnt);
if (err)
goto out_unlock;
err = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
lower_new_dentry);
if (err || !lower_new_dentry->d_inode)
goto out;
err = sdcardfskk_interpose(new_dentry, dir->i_sb, &lower_new_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, lower_new_dentry->d_inode);
fsstack_copy_inode_size(dir, lower_new_dentry->d_inode);
old_dentry->d_inode->i_nlink =
sdcardfskk_lower_inode(old_dentry->d_inode)->i_nlink;
i_size_write(new_dentry->d_inode, file_size_save);
out:
mnt_drop_write(lower_new_path.mnt);
out_unlock:
unlock_dir(lower_dir_dentry);
sdcardfskk_put_lower_path(old_dentry, &lower_old_path);
sdcardfskk_put_lower_path(new_dentry, &lower_new_path);
REVERT_CRED();
return err;
}
static int sdcardfskk_permission(struct inode *inode, int mask, unsigned int flags)
{
int err;
if (flags & IPERM_FLAG_RCU)
return -ECHILD;
/*
* Permission check on sdcardfskk inode.
* Calling process should have AID_SDCARD_RW permission
*/
err = generic_permission(inode, mask, 0, inode->i_op->check_acl);
/* XXX
* Original sdcardfskk code calls inode_permission(lower_inode,.. )
* for checking inode permission. But doing such things here seems
* duplicated work, because the functions called after this func,
* such as vfs_create, vfs_unlink, vfs_rename, and etc,
* does exactly same thing, i.e., they calls inode_permission().
* So we just let they do the things.
* If there are any security hole, just uncomment following if block.
*/
#if 0
if (!err) {
/*
* Permission check on lower_inode(=EXT4).
* we check it with AID_MEDIA_RW permission
*/
struct inode *lower_inode;
OVERRIDE_CRED(SDCARDFSKK_SB(inode->sb));
lower_inode = sdcardfskk_lower_inode(inode);
err = inode_permission(lower_inode, mask);
REVERT_CRED();
}
#endif
return err;
}
static int sdcardfskk_getattr(struct vfsmount *mnt, struct dentry *dentry,
struct kstat *stat)
{
struct dentry *lower_dentry;
struct inode *inode;
struct inode *lower_inode;
struct path lower_path;
struct dentry *parent;
struct sdcardfskk_sb_info *sbi = SDCARDFSKK_SB(dentry->d_sb);
parent = dget_parent(dentry);
if(!check_caller_access_to_name(parent->d_inode, dentry->d_name.name,
sbi->options.derive, 0, 0)) {
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" dentry: %s, task:%s\n",
__func__, dentry->d_name.name, current->comm);
dput(parent);
return -EACCES;
}
dput(parent);
inode = dentry->d_inode;
sdcardfskk_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_inode = sdcardfskk_lower_inode(inode);
fsstack_copy_attr_all(inode, lower_inode);
fsstack_copy_inode_size(inode, lower_inode);
/* if the dentry has been moved from other location
* so, on this stage, its derived permission must be
* rechecked from its private field.
*/
fix_derived_permission(inode);
generic_fillattr(inode, stat);
sdcardfskk_put_lower_path(dentry, &lower_path);
return 0;
}
static int sdcardfskk_show_options(struct seq_file *m, struct vfsmount *mnt)
{
struct sdcardfskk_sb_info *sbi = SDCARDFSKK_SB(mnt->mnt_sb);
struct sdcardfskk_mount_options *opts = &sbi->options;
if (opts->fs_low_uid != 0)
seq_printf(m, ",uid=%u", opts->fs_low_uid);
if (opts->fs_low_gid != 0)
seq_printf(m, ",gid=%u", opts->fs_low_gid);
if (opts->derive == DERIVE_NONE)
seq_printf(m, ",derive=none");
else if (opts->derive == DERIVE_LEGACY)
seq_printf(m, ",derive=legacy");
else if (opts->derive == DERIVE_UNIFIED)
seq_printf(m, ",derive=unified");
if (opts->reserved_mb != 0)
seq_printf(m, ",reserved=%uMB", opts->reserved_mb);
return 0;
};
static int sdcardfskk_open(struct inode *inode, struct file *file)
{
int err = 0;
struct file *lower_file = NULL;
struct path lower_path;
struct dentry *dentry = file->f_path.dentry;
struct dentry *parent = dget_parent(dentry);
struct sdcardfskk_sb_info *sbi = SDCARDFSKK_SB(dentry->d_sb);
const struct cred *saved_cred = NULL;
int has_rw;
/* don't open unhashed/deleted files */
if (d_unhashed(dentry)) {
err = -ENOENT;
goto out_err;
}
has_rw = get_caller_has_rw_locked_kitkat(sbi->pkgl_id, sbi->options.derive);
if(!check_caller_access_to_name_kitkat(parent->d_inode, dentry->d_name.name,
sbi->options.derive,
open_flags_to_access_mode_kitkat(file->f_flags), has_rw)) {
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" dentry: %s, task:%s\n",
__func__, dentry->d_name.name, current->comm);
err = -EACCES;
goto out_err;
}
/* save current_cred and override it */
OVERRIDE_CRED(sbi, saved_cred);
file->private_data =
kzalloc(sizeof(struct sdcardfskk_file_info), GFP_KERNEL);
if (!SDCARDFSKK_F(file)) {
err = -ENOMEM;
goto out_revert_cred;
}
/* open lower object and link sdcardfskk's file struct to lower's */
sdcardfskk_get_lower_path(file->f_path.dentry, &lower_path);
lower_file = dentry_open(lower_path.dentry, lower_path.mnt,
file->f_flags, current_cred());
if (IS_ERR(lower_file)) {
err = PTR_ERR(lower_file);
lower_file = sdcardfskk_lower_file(file);
if (lower_file) {
sdcardfskk_set_lower_file(file, NULL);
fput(lower_file); /* fput calls dput for lower_dentry */
}
} else {
sdcardfskk_set_lower_file(file, lower_file);
}
if (err)
kfree(SDCARDFSKK_F(file));
else {
mutex_lock(&inode->i_mutex);
sdcardfskk_copy_inode_attr(inode, sdcardfskk_lower_inode(inode));
fix_derived_permission(inode);
mutex_unlock(&inode->i_mutex);
}
out_revert_cred:
REVERT_CRED(saved_cred);
out_err:
dput(parent);
return err;
}
/*
* Main driver function for sdcardfskk's lookup.
*
* Returns: NULL (ok), ERR_PTR if an error occurred.
* Fills in lower_parent_path with <dentry,mnt> on success.
*/
static struct dentry *__sdcardfskk_lookup(struct dentry *dentry,
struct nameidata *nd, struct path *lower_parent_path)
{
int err = 0;
struct vfsmount *lower_dir_mnt;
struct dentry *lower_dir_dentry = NULL;
struct dentry *lower_dentry;
const char *name;
struct nameidata lower_nd;
struct path lower_path;
struct qstr this;
struct sdcardfskk_sb_info *sbi;
sbi = SDCARDFSKK_SB(dentry->d_sb);
/* must initialize dentry operations */
d_set_d_op(dentry, &sdcardfskk_ci_dops);
if (IS_ROOT(dentry))
goto out;
name = dentry->d_name.name;
/* now start the actual lookup procedure */
lower_dir_dentry = lower_parent_path->dentry;
lower_dir_mnt = lower_parent_path->mnt;
/* Use vfs_path_lookup to check if the dentry exists or not */
if (sbi->options.lower_fs == LOWER_FS_EXT4) {
err = vfs_path_lookup(lower_dir_dentry, lower_dir_mnt, name,
LOOKUP_CASE_INSENSITIVE, &lower_nd);
} else if (sbi->options.lower_fs == LOWER_FS_FAT) {
err = vfs_path_lookup(lower_dir_dentry, lower_dir_mnt, name, 0,
&lower_nd);
}
/* no error: handle positive dentries */
if (!err) {
/* check if the dentry is an obb dentry
* if true, the lower_inode must be replaced with
* the inode of the graft path */
if(need_graft_path_kitkat(dentry)) {
/* setup_obb_dentry_kitkat()
* The lower_path will be stored to the dentry's orig_path
* and the base obbpath will be copyed to the lower_path variable.
* if an error returned, there's no change in the lower_path
* returns: -ERRNO if error (0: no error) */
err = setup_obb_dentry_kitkat(dentry, &lower_nd.path);
if(err) {
/* if the sbi->obbpath is not available, we can optionally
* setup the lower_path with its orig_path.
* but, the current implementation just returns an error
* because the sdcard daemon also regards this case as
* a lookup fail. */
printk(KERN_INFO "sdcardfskk: base obbpath is not available\n");
sdcardfskk_put_reset_orig_path(dentry);
goto out;
}
}
sdcardfskk_set_lower_path(dentry, &lower_nd.path);
err = sdcardfskk_interpose(dentry, dentry->d_sb, &lower_nd.path);
if (err) /* path_put underlying path on error */
sdcardfskk_put_reset_lower_path(dentry);
goto out;
}
/*
* We don't consider ENOENT an error, and we want to return a
* negative dentry.
*/
if (err && err != -ENOENT)
goto out;
/* instatiate a new negative dentry */
this.name = name;
this.len = strlen(name);
this.hash = full_name_hash(this.name, this.len);
lower_dentry = d_lookup(lower_dir_dentry, &this);
if (lower_dentry)
goto setup_lower;
lower_dentry = d_alloc(lower_dir_dentry, &this);
if (!lower_dentry) {
err = -ENOMEM;
goto out;
}
d_add(lower_dentry, NULL); /* instantiate and hash */
setup_lower:
lower_path.dentry = lower_dentry;
lower_path.mnt = mntget(lower_dir_mnt);
sdcardfskk_set_lower_path(dentry, &lower_path);
/*
* If the intent is to create a file, then don't return an error, so
* the VFS will continue the process of making this negative dentry
* into a positive one.
*/
if (nd) {
if (nd->flags & (LOOKUP_CREATE|LOOKUP_RENAME_TARGET))
err = 0;
} else
err = 0;
out:
return ERR_PTR(err);
}
static int sdcardfskk_setattr(struct dentry *dentry, struct iattr *ia)
{
int err = 0;
struct dentry *lower_dentry;
struct inode *inode;
struct inode *lower_inode;
struct path lower_path;
struct iattr lower_ia;
struct sdcardfskk_sb_info *sbi = SDCARDFSKK_SB(dentry->d_sb);
struct dentry *parent;
int has_rw;
inode = dentry->d_inode;
/*
* Check if user has permission to change inode. We don't check if
* this user can change the lower inode: that should happen when
* calling notify_change on the lower inode.
*/
err = inode_change_ok(inode, ia);
/* no vfs_XXX operations required, cred overriding will be skipped. wj*/
if (!err) {
/* check the Android group ID */
has_rw = get_caller_has_rw_locked(sbi->pkgl_id, sbi->options.derive);
parent = dget_parent(dentry);
if(!check_caller_access_to_name(parent->d_inode, dentry->d_name.name,
sbi->options.derive, 1, has_rw)) {
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" dentry: %s, task:%s\n",
__func__, dentry->d_name.name, current->comm);
err = -EACCES;
}
dput(parent);
}
if (err)
goto out_err;
sdcardfskk_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_inode = sdcardfskk_lower_inode(inode);
/* prepare our own lower struct iattr (with the lower file) */
memcpy(&lower_ia, ia, sizeof(lower_ia));
if (ia->ia_valid & ATTR_FILE)
lower_ia.ia_file = sdcardfskk_lower_file(ia->ia_file);
lower_ia.ia_valid &= ~(ATTR_UID | ATTR_GID | ATTR_MODE);
/*
* If shrinking, first truncate upper level to cancel writing dirty
* pages beyond the new eof; and also if its' maxbytes is more
* limiting (fail with -EFBIG before making any change to the lower
* level). There is no need to vmtruncate the upper level
* afterwards in the other cases: we fsstack_copy_inode_size from
* the lower level.
*/
if (current->mm)
down_write(¤t->mm->mmap_sem);
if (ia->ia_valid & ATTR_SIZE) {
err = inode_newsize_ok(inode, ia->ia_size);
if (err) {
if (current->mm)
up_write(¤t->mm->mmap_sem);
goto out;
}
truncate_setsize(inode, ia->ia_size);
}
/*
* mode change is for clearing setuid/setgid bits. Allow lower fs
* to interpret this in its own way.
*/
if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
lower_ia.ia_valid &= ~ATTR_MODE;
/* notify the (possibly copied-up) lower inode */
/*
* Note: we use lower_dentry->d_inode, because lower_inode may be
* unlinked (no inode->i_sb and i_ino==0. This happens if someone
* tries to open(), unlink(), then ftruncate() a file.
*/
mutex_lock(&lower_dentry->d_inode->i_mutex);
err = notify_change(lower_dentry, &lower_ia); /* note: lower_ia */
mutex_unlock(&lower_dentry->d_inode->i_mutex);
if (current->mm)
up_write(¤t->mm->mmap_sem);
if (err)
goto out;
/* get attributes from the lower inode */
fsstack_copy_attr_all(inode, lower_inode);
/* update derived permission of the upper inode */
fix_derived_permission(inode);
/*
* Not running fsstack_copy_inode_size(inode, lower_inode), because
* VFS should update our inode size, and notify_change on
* lower_inode should update its size.
*/
out:
sdcardfskk_put_lower_path(dentry, &lower_path);
out_err:
return err;
}
/*
* The locking rules in sdcardfskk_rename are complex. We could use a simpler
* superblock-level name-space lock for renames and copy-ups.
*/
static int sdcardfskk_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
int err = 0;
struct dentry *lower_old_dentry = NULL;
struct dentry *lower_new_dentry = NULL;
struct dentry *lower_old_dir_dentry = NULL;
struct dentry *lower_new_dir_dentry = NULL;
struct dentry *trap = NULL;
struct dentry *new_parent = NULL;
struct path lower_old_path, lower_new_path;
struct sdcardfskk_sb_info *sbi = SDCARDFSKK_SB(old_dentry->d_sb);
const struct cred *saved_cred = NULL;
int has_rw = get_caller_has_rw_locked(sbi->pkgl_id, sbi->options.derive);
if(!check_caller_access_to_name(old_dir, old_dentry->d_name.name,
sbi->options.derive, 1, has_rw) ||
!check_caller_access_to_name(new_dir, new_dentry->d_name.name,
sbi->options.derive, 1, has_rw)) {
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" new_dentry: %s, task:%s\n",
__func__, new_dentry->d_name.name, current->comm);
err = -EACCES;
goto out_eacces;
}
/* save current_cred and override it */
OVERRIDE_CRED(SDCARDFSKK_SB(old_dir->i_sb), saved_cred);
sdcardfskk_get_real_lower(old_dentry, &lower_old_path);
sdcardfskk_get_lower_path(new_dentry, &lower_new_path);
lower_old_dentry = lower_old_path.dentry;
lower_new_dentry = lower_new_path.dentry;
lower_old_dir_dentry = dget_parent(lower_old_dentry);
lower_new_dir_dentry = dget_parent(lower_new_dentry);
trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
/* source should not be ancestor of target */
if (trap == lower_old_dentry) {
err = -EINVAL;
goto out;
}
/* target should not be ancestor of source */
if (trap == lower_new_dentry) {
err = -ENOTEMPTY;
goto out;
}
err = mnt_want_write(lower_old_path.mnt);
if (err)
goto out;
err = mnt_want_write(lower_new_path.mnt);
if (err)
goto out_drop_old_write;
err = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
lower_new_dir_dentry->d_inode, lower_new_dentry);
if (err)
goto out_err;
/* Copy attrs from lower dir, but i_uid/i_gid */
fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
fsstack_copy_inode_size(new_dir, lower_new_dir_dentry->d_inode);
fix_derived_permission(new_dir);
if (new_dir != old_dir) {
fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
fsstack_copy_inode_size(old_dir, lower_old_dir_dentry->d_inode);
fix_derived_permission(old_dir);
/* update the derived permission of the old_dentry
* with its new parent
*/
new_parent = dget_parent(new_dentry);
if(new_parent) {
if(old_dentry->d_inode) {
get_derived_permission(new_parent, old_dentry);
fix_derived_permission(old_dentry->d_inode);
}
dput(new_parent);
}
}
out_err:
mnt_drop_write(lower_new_path.mnt);
out_drop_old_write:
mnt_drop_write(lower_old_path.mnt);
out:
unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
dput(lower_old_dir_dentry);
dput(lower_new_dir_dentry);
sdcardfskk_put_real_lower(old_dentry, &lower_old_path);
sdcardfskk_put_lower_path(new_dentry, &lower_new_path);
REVERT_CRED(saved_cred);
out_eacces:
return err;
}
static int sdcardfskk_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
int err = 0;
int make_nomedia_in_obb = 0;
struct dentry *lower_dentry;
struct dentry *lower_parent_dentry = NULL;
struct path lower_path;
struct sdcardfskk_sb_info *sbi = SDCARDFSKK_SB(dentry->d_sb);
const struct cred *saved_cred = NULL;
struct sdcardfskk_inode_info *pi = SDCARDFSKK_I(dir);
char *page_buf;
char *nomedia_dir_name;
char *nomedia_fullpath;
int fullpath_namelen;
int touch_err = 0;
int has_rw = get_caller_has_rw_locked(sbi->pkgl_id, sbi->options.derive);
if(!check_caller_access_to_name(dir, dentry->d_name.name, sbi->options.derive, 1, has_rw)) {
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" dentry: %s, task:%s\n",
__func__, dentry->d_name.name, current->comm);
err = -EACCES;
goto out_eacces;
}
/* save current_cred and override it */
OVERRIDE_CRED(SDCARDFSKK_SB(dir->i_sb), saved_cred);
/* check disk space */
if (!check_min_free_space(dentry, 0, 1)) {
printk(KERN_INFO "sdcardfskk: No minimum free space.\n");
err = -ENOSPC;
goto out_revert;
}
/* the lower_dentry is negative here */
sdcardfskk_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_parent_dentry = lock_parent(lower_dentry);
err = mnt_want_write(lower_path.mnt);
if (err)
goto out_unlock;
/* set last 16bytes of mode field to 0775 */
mode = (mode & S_IFMT) | 00775;
err = vfs_mkdir(lower_parent_dentry->d_inode, lower_dentry, mode);
if (err)
goto out;
/* if it is a local obb dentry, setup it with the base obbpath */
if(need_graft_path(dentry)) {
err = setup_obb_dentry(dentry, &lower_path);
if(err) {
/* if the sbi->obbpath is not available, the lower_path won't be
* changed by setup_obb_dentry() but the lower path is saved to
* its orig_path. this dentry will be revalidated later.
* but now, the lower_path should be NULL */
sdcardfskk_put_reset_lower_path(dentry);
/* the newly created lower path which saved to its orig_path or
* the lower_path is the base obbpath.
* therefore, an additional path_get is required */
path_get(&lower_path);
} else
make_nomedia_in_obb = 1;
}
err = sdcardfskk_interpose(dentry, dir->i_sb, &lower_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, sdcardfskk_lower_inode(dir));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
/* update number of links on parent directory */
dir->i_nlink = sdcardfskk_lower_inode(dir)->i_nlink;
if ((sbi->options.derive == DERIVE_UNIFIED) && (!strcasecmp(dentry->d_name.name, "obb"))
&& (pi->perm == PERM_ANDROID) && (pi->userid == 0))
make_nomedia_in_obb = 1;
/* When creating /Android/data and /Android/obb, mark them as .nomedia */
if (make_nomedia_in_obb ||
((pi->perm == PERM_ANDROID) && (!strcasecmp(dentry->d_name.name, "data")))) {
page_buf = (char *)__get_free_page(GFP_KERNEL);
if (!page_buf) {
printk(KERN_ERR "sdcardfskk: failed to allocate page buf\n");
goto out;
}
nomedia_dir_name = d_absolute_path(&lower_path, page_buf, PAGE_SIZE);
if (IS_ERR(nomedia_dir_name)) {
free_page((unsigned long)page_buf);
printk(KERN_ERR "sdcardfskk: failed to get .nomedia dir name\n");
goto out;
}
fullpath_namelen = page_buf + PAGE_SIZE - nomedia_dir_name - 1;
fullpath_namelen += strlen("/.nomedia");
nomedia_fullpath = kzalloc(fullpath_namelen + 1, GFP_KERNEL);
if (!nomedia_fullpath) {
free_page((unsigned long)page_buf);
printk(KERN_ERR "sdcardfskk: failed to allocate .nomedia fullpath buf\n");
goto out;
}
strcpy(nomedia_fullpath, nomedia_dir_name);
free_page((unsigned long)page_buf);
strcat(nomedia_fullpath, "/.nomedia");
touch_err = touch(nomedia_fullpath, 0664);
if (touch_err) {
printk(KERN_ERR "sdcardfskk: failed to touch(%s): %d\n",
nomedia_fullpath, touch_err);
kfree(nomedia_fullpath);
goto out;
}
kfree(nomedia_fullpath);
}
out:
mnt_drop_write(lower_path.mnt);
out_unlock:
unlock_dir(lower_parent_dentry);
sdcardfskk_put_lower_path(dentry, &lower_path);
out_revert:
REVERT_CRED(saved_cred);
out_eacces:
return err;
}
