On 3/24/23 11:17, Mike Christie wrote:
Add callouts for reading keys and reservations. This allows LIO to support the READ_KEYS and READ_RESERVATION commands and will allow dm-multipath to optimize it's error handling so it can check if it's getting an error because there's an existing reservation or if we need to retry different paths. Note: This only initially adds the struct definitions in the kernel as I'm not sure if we wanted to export the interface to userspace yet. read_keys and read_reservation are exactly what dm-multipath and LIO need, but for a userspace interface we may want something like SCSI's READ_FULL_STATUS and NVMe's report reservation commands. Those are overkill for dm/LIO and READ_FULL_STATUS is sometimes broken for SCSI devices.
Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>