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;
}
/*
* returns: -ERRNO if error (returned to user)
* 0: tell VFS to invalidate dentry
* 1: dentry is valid
*/
static int sdcardfskk_d_revalidate(struct dentry *dentry, struct nameidata *nd)
{
int err = 1;
struct path parent_lower_path, lower_path;
struct dentry *parent_dentry = NULL;
struct dentry *parent_lower_dentry = NULL;
struct dentry *lower_cur_parent_dentry = NULL;
struct dentry *lower_dentry = NULL;
if (nd && nd->flags & LOOKUP_RCU)
return -ECHILD;
spin_lock(&dentry->d_lock);
if (IS_ROOT(dentry)) {
spin_unlock(&dentry->d_lock);
return 1;
}
spin_unlock(&dentry->d_lock);
/* check uninitialized obb_dentry and
* whether the base obbpath has been changed or not */
if (is_obbpath_invalid(dentry)) {
d_drop(dentry);
return 0;
}
parent_dentry = dget_parent(dentry);
sdcardfskk_get_lower_path(parent_dentry, &parent_lower_path);
sdcardfskk_get_real_lower(dentry, &lower_path);
parent_lower_dentry = parent_lower_path.dentry;
lower_dentry = lower_path.dentry;
lower_cur_parent_dentry = dget_parent(lower_dentry);
spin_lock(&lower_dentry->d_lock);
if (d_unhashed(lower_dentry)) {
spin_unlock(&lower_dentry->d_lock);
d_drop(dentry);
err = 0;
goto out;
}
spin_unlock(&lower_dentry->d_lock);
if (parent_lower_dentry != lower_cur_parent_dentry) {
d_drop(dentry);
err = 0;
goto out;
}
if (dentry < lower_dentry) {
spin_lock(&dentry->d_lock);
spin_lock(&lower_dentry->d_lock);
} else {
spin_lock(&lower_dentry->d_lock);
spin_lock(&dentry->d_lock);
}
if (dentry->d_name.len != lower_dentry->d_name.len) {
__d_drop(dentry);
err = 0;
} else if (strncasecmp(dentry->d_name.name, lower_dentry->d_name.name,
dentry->d_name.len) != 0) {
__d_drop(dentry);
err = 0;
}
if (dentry < lower_dentry) {
spin_unlock(&lower_dentry->d_lock);
spin_unlock(&dentry->d_lock);
} else {
spin_unlock(&dentry->d_lock);
spin_unlock(&lower_dentry->d_lock);
}
out:
dput(parent_dentry);
dput(lower_cur_parent_dentry);
sdcardfskk_put_lower_path(parent_dentry, &parent_lower_path);
sdcardfskk_put_real_lower(dentry, &lower_path);
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;
}