Dave, > Possibly unintentionally, I didn't call it REQ_OP_PROVISION but that's > what I intended - the operation does not contain data at all. It's an > operation like REQ_OP_DISCARD or REQ_OP_WRITE_ZEROS - it contains a > range of sectors that need to be provisioned (or discarded), and > nothing else. Yep. That's also how SCSI defines it. The act of provisioning a block range is done through an UNMAP command using a special flag. All it does is pin down those LBAs so future writes to them won't result in ENOSPC. -- Martin K. Petersen Oracle Linux Engineering