ecryptfs_set_dentry_lower(sb->s_root, lower_root);
ecryptfs_set_dentry_lower_mnt(sb->s_root, lower_mnt);
rc = ecryptfs_interpose(lower_root, sb->s_root, sb, 0);
ecryptfs_set_dentry_lower(sb->s_root, lower_root);
ecryptfs_set_dentry_lower_mnt(sb->s_root, lower_mnt);
rc = ecryptfs_interpose(lower_root, sb->s_root, sb, 0);