if (IS_ERR(acl)) return PTR_ERR(acl);
ext2_check_acl(struct inode *inode, int mask){	struct posix_acl *acl = ext2_get_acl(inode, ACL_TYPE_ACCESS);	if (acl) {		int error = posix_acl_permission(inode, acl, mask);		posix_acl_release(acl);		return error;	}	return -EAGAIN;}