Klaus Jensen <k.jen...@samsung.com> 于2023年8月24日周四 02:53写道： > > On Aug 23 22:58, Sam Li wrote: > > Stefan Hajnoczi <stefa...@gmail.com> 于2023年8月23日周三 22:41写道： > > > > > > On Wed, 23 Aug 2023 at 10:24, Sam Li <faithilike...@gmail.com> wrote: > > > > > > > > Hi Stefan, > > > > > > > > Stefan Hajnoczi <stefa...@gmail.com> 于2023年8月23日周三 21:26写道： > > > > > > > > > > Hi Sam and Klaus, > > > > > Val is adding nvme-io_uring ZNS support to libblkio > > > > > (https://gitlab.com/libblkio/libblkio/-/merge_requests/221) and asked > > > > > how to test the size of the last zone when the namespace's total size > > > > > is not a multiple of the zone size. > > > > > > > > I think a zone report operation can do the trick. Given zone configs, > > > > the size of last zone should be [size - (nr_zones - 1) * zone_size]. > > > > Reporting last zone on such devices tells whether the value is > > > > correct. > > > > > > In nvme_ns_zoned_check_calc_geometry() the number of zones is rounded > > > down: > > > > > > ns->num_zones = le64_to_cpu(ns->id_ns.nsze) / ns->zone_size; > > > > > > Afterwards nsze is recalculated as follows: > > > > > > ns->id_ns.nsze = cpu_to_le64(ns->num_zones * ns->zone_size); > > > > > > I interpret this to mean that when the namespace's total size is not a > > > multiple of the zone size, then the last part will be ignored and not > > > exposed as a zone. > > > > I see. Current ZNS emulation does not support this case. > > > > NVMe Zoned Namespaces requires all zones to be the same size. The > "trailing zone" is a thing in SMR HDDs.
Thanks! Then qcow2 with ZNS should also ignore the trailing zone. Sam
