Re: [PATCH v2] scsi: scsi_debug: Zero clear zones at reset write pointer

[Douglas Gilbert <dgilbert@interlog.com>]

On 2021-11-22 1:32 a.m., Damien Le Moal wrote:
> On 2021/11/22 15:12, Shin'ichiro Kawasaki wrote:
>> When reset write pointer is requested to scsi_debug devices with zoned
>> model, positions of write pointers are reset, but the data in the target
>> zones are not cleared. Read to the zones returns data written before the
>> reset write pointer. This unexpected left data is confusing and does not
>> allow using scsi_debug for stale page cache test of the BLKRESETZONE
>> ioctl. Hence, zero clear the written data in the zones at reset write
>> pointer.
>>
>> Fixes: f0d1cf9378bd ("scsi: scsi_debug: Add ZBC zone commands")
>> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
>> ---
>> Changes from v1:
>> * Zero clear only the written data area in non-empty zones
>>
>>   drivers/scsi/scsi_debug.c | 5 +++++
>>   1 file changed, 5 insertions(+)
>>
>> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
>> index 1d0278da9041..1ef9907c479a 100644
>> --- a/drivers/scsi/scsi_debug.c
>> +++ b/drivers/scsi/scsi_debug.c
>> @@ -4653,6 +4653,7 @@ static void zbc_rwp_zone(struct sdebug_dev_info *devip,
>>   			 struct sdeb_zone_state *zsp)
>>   {
>>   	enum sdebug_z_cond zc;
>> +	struct sdeb_store_info *sip = devip2sip(devip, false);
>>   
>>   	if (zbc_zone_is_conv(zsp))
>>   		return;
>> @@ -4664,6 +4665,10 @@ static void zbc_rwp_zone(struct sdebug_dev_info *devip,
>>   	if (zsp->z_cond == ZC4_CLOSED)
>>   		devip->nr_closed--;
>>   
>> +	if (zsp->z_wp > zsp->z_start)
>> +		memset(sip->storep + zsp->z_start * sdebug_sector_size, 0,
>> +		       (zsp->z_wp - zsp->z_start) * sdebug_sector_size);
>> +
>>   	zsp->z_non_seq_resource = false;
>>   	zsp->z_wp = zsp->z_start;
>>   	zsp->z_cond = ZC1_EMPTY;
>>
> 
> Looks good.
> 
> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

Thanks.

Acked-by: Douglas Gilbert <dgilbert@interlog.com>