Re: [PATCH v2] block: ublk: enable zoned storage support

From: Andreas Hindborg
Date: Mon Feb 27 2023 - 10:39:34 EST



Minwoo Im <minwoo.im.dev@xxxxxxxxx> writes:

> On 23-02-24 21:05:01, Andreas Hindborg wrote:
>> +static int ublk_report_zones(struct gendisk *disk, sector_t sector,
>> + unsigned int nr_zones, report_zones_cb cb,
>> + void *data)
>> +{
>> + struct ublk_device *ub;
>> + unsigned int zone_size;
>> + unsigned int first_zone;
>> + int ret = 0;
>> +
>> + ub = disk->private_data;
>> +
>> + if (!(ub->dev_info.flags & UBLK_F_ZONED))
>> + return -EINVAL;
>> +
>> + zone_size = disk->queue->limits.chunk_sectors;
>> + first_zone = sector >> ilog2(zone_size);
>> + nr_zones = min(ub->ub_disk->nr_zones - first_zone, nr_zones);
>> +
>> + for (unsigned int i = 0; i < nr_zones; i++) {
>> + struct request *req;
>> + blk_status_t status;
>> + struct blk_zone info = {0};
>> +
>> + req = blk_mq_alloc_request(disk->queue, REQ_OP_DRV_IN, 0);
>> +
>> + if (IS_ERR(req)) {
>> + ret = PTR_ERR(req);
>> + goto out;
>> + }
>
> Can we just return directly just like above (-EINVAL)?
>
> if (IS_ERR(req))
> return PTR_ERR(req);

Yes, I agree.

>
>> +
>> + req->__sector = sector;
>> +
>> + ret = blk_rq_map_kern(disk->queue, req, &info, sizeof(info),
>> + GFP_KERNEL);
>> +
>> + if (ret)
>> + goto out;
>
> If we really have to use goto here, then I think we have choices:
> put blk_mq_free_request(req); here or put it to the out: area.

Lets free here and drop the goto.

Thanks,
Andreas

>> +
>> + status = blk_execute_rq(req, 0);
>> + ret = blk_status_to_errno(status);
>> + if (ret)
>> + goto out;
>> +
>> + blk_mq_free_request(req);
>> +
>> + ret = cb(&info, i, data);
>> + if (ret)
>> + goto out;
>> +
>> + /* A zero length zone means don't ask for more zones */
>> + if (!info.len) {
>> + nr_zones = i;
>> + break;
>> + }
>> +
>> + sector += zone_size;
>> + }
>> + ret = nr_zones;
>> +
>> + out:
>> + return ret;
>> +}