Added new public header for zoned bdev. Zoned bdev is an
extension of the bdev interface. Generic concept comes
from ATA/SCSI and is also being worked as an NVMe TP.
Zoned device logical blocks space is divided into fixed-sized
zones. Each zone is described by its start logical block address
and capacity. Writes to a single zone need to be sequential.
After zone is fully written it need to be reset to write to it
again. Such writing schema could be very beneficial in terms of
write amplification factor for NAND based devices.
SPDK Flash Translation Layer library will be consuming this
interface in the future.
Extending SPDK bdev interface will allow to use existing bdev
infrastructure for this new type of devices.
Zoned device have several properties defined in spdk_bdev
structure:
- zone_size: default size of each zone
- max_open_zone: maximum number of open zones
- optimal_open_zones: optimal number of open zones to get
best performance on writes
Single zone properties are defined in spdk_bdev_zone_info
structure:
- start_lba: first logical block of z zone
- write_pointer: logical block address in the zone at
which next write shall occur.
- capacity: maximum number of logical blocks that may
be written in the zone when zone is empty.
- state: zone state
Several zone states are defined: Empty, Open, Full, Closed,
Read Only and Offline.
To change zone state zone actions are defined: Close, Finish,
Open and Reset.
Change-Id: I5fcc22d548c15743329344cae96f5ff73e268504
Signed-off-by: Wojciech Malikowski <wojciech.malikowski@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/460642
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Maciej Szwed <maciej.szwed@intel.com>
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