Re: [PATCH 1/2] scsi: sd_zbc: do not enforce READ/WRITE (16) on host-aware devices

[Damien Le Moal <damien.lemoal@opensource.wdc.com>]

On 11/9/22 11:59, Shin'ichiro Kawasaki wrote:
> ZBC Zoned Block Commands specification mandates READ (16) and WRITE (16)
> commands only for host-managed zoned block devices. It does not mandate
> the commands for host-aware zoned block devices. However, current
> sd_zbc_read_zones() code assumes the commands were mandated for host-
> aware devices also and enforces the commands. If the host-aware drives
> do not support the commands, they may fail.
> 
> To conform to the ZBC specification and to avoid the failure, check
> device type and modify use_16_for_rw and use_10_for_rw flags only for
> host-managed zoned block devices, so that the READ (16) and WRITE (16)
> commands are not enforced on host-aware zoned block devices.
> 
> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
> ---
>  drivers/scsi/sd_zbc.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
> index bd15624c6322..4717a55dbf35 100644
> --- a/drivers/scsi/sd_zbc.c
> +++ b/drivers/scsi/sd_zbc.c
> @@ -921,9 +921,11 @@ int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 buf[SD_BUF_SIZE])
>  		return 0;
>  	}
>  
> -	/* READ16/WRITE16 is mandatory for ZBC disks */
> -	sdkp->device->use_16_for_rw = 1;
> -	sdkp->device->use_10_for_rw = 0;
> +	/* READ16/WRITE16 is mandatory for host-managed devices */
> +	if (sdkp->device->type == TYPE_ZBC) {
> +		sdkp->device->use_16_for_rw = 1;
> +		sdkp->device->use_10_for_rw = 0;
> +	}
>  
>  	if (!blk_queue_is_zoned(q)) {
>  		/*

Looks good to me.

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

-- 
Damien Le Moal
Western Digital Research