STIOC_SET_BLK_PROTECTION

This IOCTL sets status of the drive's Logical Block Protection. All fields are configurable except lbp_capable and reserved. The structures and defines are the same as for STIOC_QUERY_BLK_PROTECTION. To use this IOCTL, issue the following call.
rc = ioctl(fd, STIOC_SET_BLK_PROTECTION, &lbp);