Re: [RFC v4 2/9] qemu-io: add zoned block device operations.

[Damien Le Moal]

On 7/27/22 23:13, Stefan Hajnoczi wrote:
> On Mon, 11 Jul 2022 at 22:17, Sam Li <faithilikerun@gmail.com> wrote:
>> +int bdrv_co_zone_report(BlockDriverState *bs, int64_t offset,
>> +                        int64_t *nr_zones,
>> +                        BlockZoneDescriptor *zones)
>> +{
>> +    BlockDriver *drv = bs->drv;
>> +    CoroutineIOCompletion co = {
>> +            .coroutine = qemu_coroutine_self(),
>> +    };
>> +    IO_CODE();
>> +
>> +    bdrv_inc_in_flight(bs);
>> +    if (!drv || (!drv->bdrv_co_zone_report)) {

You can drop the inner parenthesis for "(!drv->bdrv_co_zone_report)".

>> +        co.ret = -ENOTSUP;
>> +        goto out;
>> +    }
>> +
>> +    if (drv->bdrv_co_zone_report) {
> 
> At this point we know drv->bdrv_co_zone_report is non-NULL because it
> has been checked already. The if statement can be dropped.
> 
>> +        co.ret = drv->bdrv_co_zone_report(bs, offset, nr_zones, zones);
>> +    } else {
>> +        co.ret = -ENOTSUP;
> 
> This case is already handled by if (... ||
> (!drv->bdrv_co_zone_report)) above. The else body can be dropped.
> 
>> +        goto out;
>> +        qemu_coroutine_yield();
>> +    }
>> +
>> +out:
>> +    bdrv_dec_in_flight(bs);
>> +    return co.ret;
>> +}
>> +
>> +int bdrv_co_zone_mgmt(BlockDriverState *bs, enum zone_op op,
> 
> Please follow QEMU coding style and typedef BdrvZoneOp instead of
> writing out enum zone_op.
> 
>> +        int64_t offset, int64_t len)
>> +{
>> +    BlockDriver *drv = bs->drv;
>> +    CoroutineIOCompletion co = {
>> +            .coroutine = qemu_coroutine_self(),
>> +    };
>> +    IO_CODE();
>> +
>> +    bdrv_inc_in_flight(bs);
>> +    if (!drv || (!drv->bdrv_co_zone_mgmt)) {
>> +        co.ret = -ENOTSUP;
>> +        goto out;
>> +    }
>> +
>> +    if (drv->bdrv_co_zone_mgmt) {
>> +        co.ret = drv->bdrv_co_zone_mgmt(bs, op, offset, len);
>> +    } else {
>> +        co.ret = -ENOTSUP;
>> +        goto out;
>> +        qemu_coroutine_yield();
>> +    }
> 
> Same comments here.
> 
>> +
>> +out:
>> +    bdrv_dec_in_flight(bs);
>> +    return co.ret;
>> +}
>> +
>>  void *qemu_blockalign(BlockDriverState *bs, size_t size)
>>  {
>>      IO_CODE();
>> diff --git a/include/block/block-io.h b/include/block/block-io.h
>> index 053a27141a..a0ae140452 100644
>> --- a/include/block/block-io.h
>> +++ b/include/block/block-io.h
>> @@ -80,6 +80,13 @@ int bdrv_co_ioctl(BlockDriverState *bs, int req, void 
>> *buf);
>>  /* Ensure contents are flushed to disk.  */
>>  int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
>>
>> +/* Report zone information of zone block device. */
>> +int coroutine_fn bdrv_co_zone_report(BlockDriverState *bs, int64_t offset,
>> +                                     int64_t *nr_zones,
>> +                                     BlockZoneDescriptor *zones);
>> +int coroutine_fn bdrv_co_zone_mgmt(BlockDriverState *bs, zone_op op,
>> +                                   int64_t offset, int64_t len);
>> +
>>  int bdrv_co_pdiscard(BdrvChild *child, int64_t offset, int64_t bytes);
>>  bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
>>  int bdrv_block_status(BlockDriverState *bs, int64_t offset,
>> @@ -289,6 +296,12 @@ bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector 
>> *qiov, int64_t pos);
>>  int generated_co_wrapper
>>  bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
>>
>> +int generated_co_wrapper
>> +blk_zone_report(BlockBackend *blk, int64_t offset, int64_t *nr_zones,
>> +                BlockZoneDescriptor *zones);
>> +int generated_co_wrapper
>> +blk_zone_mgmt(BlockBackend *blk, enum zone_op op, int64_t offset, int64_t 
>> len);
>> +
>>  /**
>>   * bdrv_parent_drained_begin_single:
>>   *
>> diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
>> index 2f0d8ac25a..a88fa322d2 100644
>> --- a/qemu-io-cmds.c
>> +++ b/qemu-io-cmds.c
>> @@ -1706,6 +1706,144 @@ static const cmdinfo_t flush_cmd = {
>>      .oneline    = "flush all in-core file state to disk",
>>  };
>>
>> +static int zone_report_f(BlockBackend *blk, int argc, char **argv)
>> +{
>> +    int ret;
>> +    int64_t offset, nr_zones;
>> +
>> +    ++optind;
>> +    offset = cvtnum(argv[optind]);
>> +    ++optind;
>> +    nr_zones = cvtnum(argv[optind]);
>> +
>> +    g_autofree BlockZoneDescriptor *zones = NULL;
>> +    zones = g_new(BlockZoneDescriptor, nr_zones);
>> +    ret = blk_zone_report(blk, offset, &nr_zones, zones);
>> +    if (ret < 0) {
>> +        printf("zone report failed: %s\n", strerror(-ret));
>> +    } else {
>> +        for (int i = 0; i < nr_zones; ++i) {
>> +            printf("start: 0x%" PRIx64 ", len 0x%" PRIx64 ", "
>> +                   "cap"" 0x%" PRIx64 ",wptr 0x%" PRIx64 ", "
>> +                   "zcond:%u, [type: %u]\n",
>> +                   zones[i].start, zones[i].length, zones[i].cap, 
>> zones[i].wp,
>> +                   zones[i].cond, zones[i].type);
>> +        }
>> +    }
>> +    return ret;
>> +}
>> +
>> +static const cmdinfo_t zone_report_cmd = {
>> +        .name = "zone_report",
>> +        .altname = "zp",
>> +        .cfunc = zone_report_f,
>> +        .argmin = 2,
>> +        .argmax = 2,
>> +        .args = "offset number",
>> +        .oneline = "report zone information",
>> +};
>> +
>> +static int zone_open_f(BlockBackend *blk, int argc, char **argv)
>> +{
>> +    int ret;
>> +    int64_t offset, len;
>> +    ++optind;
>> +    offset = cvtnum(argv[optind]);
>> +    ++optind;
>> +    len = cvtnum(argv[optind]);
>> +    ret = blk_zone_mgmt(blk, zone_open, offset, len);
> 
> Please name enum constants in all caps: BDRV_ZONE_OPEN or BDRV_ZO_OPEN.


-- 
Damien Le Moal
Western Digital Research