On Mon, 2017-09-25 at 15:14 +0900, Damien Le Moal wrote: > Components relying only on the requeuest_queue structure for accessing > block devices (e.g. I/O schedulers) have a limited knowledged of the > device characteristics. In particular, the device capacity cannot be > easily discovered, which for a zoned block device also result in the > inability to easily know the number of zones of the device (the zone > size is indicated by the chunk_sectors field of the queue limits). > > Introduce the nr_zones field to the request_queue sturcture to simplify > access to this information. Also, add the bitmap seq_zone_bitmap which > indicates which zones of the device are sequential zones (write > preferred or write required). These two fields are initialized by the > low level block device driver (sd.c for ZBC/ZAC disks). They are not > initialized by stacking drivers (device mappers) handling zoned block > devices (e.g. dm-linear). Reviewed-by: Bart Van Assche <Bart.VanAssche@xxxxxxx>
