On 2022-05-04 19:03, Hannes Reinecke wrote:
> On 4/27/22 09:02, Pankaj Raghav wrote:
>> Remove the condition which disallows non-power_of_2 zone size ZNS drive
>> to be updated and use generic method to calculate number of zones
>> instead of relying on log and shift based calculation on zone size.
>>
>> The power_of_2 calculation has been replaced directly with generic
>> calculation without special handling. Both modified functions are not
>> used in hot paths, they are only used during initialization &
>> revalidation of the ZNS device.
>>
>> Reviewed-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
>> Signed-off-by: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
>> ---
}
>> ns->zsze = nvme_lba_to_sect(ns,
>> le64_to_cpu(id->lbafe[lbaf].zsze));
>> - if (!is_power_of_2(ns->zsze)) {
>> - dev_warn(ns->ctrl->device,
>> - "invalid zone size:%llu for namespace:%u\n",
>> - ns->zsze, ns->head->ns_id);
>> - status = -ENODEV;
>> - goto free_data;
>> - }
>> blk_queue_set_zoned(ns->disk, BLK_ZONED_HM);
>> blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q);
>> @@ -129,7 +122,7 @@ static void *nvme_zns_alloc_report_buffer(struct
>> nvme_ns *ns,
>> sizeof(struct nvme_zone_descriptor);
>> nr_zones = min_t(unsigned int, nr_zones,
>> - get_capacity(ns->disk) >> ilog2(ns->zsze));
>> + div64_u64(get_capacity(ns->disk), ns->zsze));
>>
> Same here; please add a helper calculating the number of zones for a
> given disk.
>
I am already using the div64_u64 helper and this is not done again
anywhere in the nvme zns driver. I am not sure if having a separate
helper for this will add value. And this is not in the hot path, so no
need for special handling.
>> bufsize = sizeof(struct nvme_zone_report) +
>> nr_zones * sizeof(struct nvme_zone_descriptor);
>> @@ -197,7 +190,7 @@ int nvme_ns_report_zones(struct nvme_ns *ns,
>> sector_t sector,
>> c.zmr.zrasf = NVME_ZRASF_ZONE_REPORT_ALL;
>> c.zmr.pr = NVME_REPORT_ZONE_PARTIAL;
>> - sector &= ~(ns->zsze - 1);
>> + sector = rounddown(sector, ns->zsze);
>> while (zone_idx < nr_zones && sector < get_capacity(ns->disk)) {
>> memset(report, 0, buflen);
>>
> Please be a bit more consistent. In the previous patches you always had
> a condition to check if it's a power_of_2 zone size, but here you are
> using the same calculation for each disk.
> So please use the check in all locations, or add a comment why the
> generic calculation is okay to use here.
>
That is a good point. I have mentioned that in my commit log that I am
not having any special handling because these calculations are not in
the hot path.
Maybe adding comments is better for clarity. I will also do it for your
previous comment.
I will queue this up for my next revision. Thanks.
> Cheers,
>
> Hannes
