Re: [RFC PATCH 6/6] scsi: scsi_debug: Reset tape setting at device reset

[John Meneghini <jmeneghi@redhat.com>]

Reviewed-by: John Meneghini <jmeneghi@redhat.com>
Tested-by: John Meneghini <jmeneghi@redhat.com>

Kai, thank you for your patches.  These are much needed improvements to the
scsi_debug tape emulator. With these changes I find that my scsi_debug tests
are now actually useful!

I've created a bunch of improvements to my tape_reset_debug_sg.sh test at:

https://github.com/johnmeneghini/tape_tests/pull/1

These changes to my tape_tests have been tested with and are dependant upon your patches at:

https://lore.kernel.org/linux-scsi/20250128142250.163901-1-Kai.Makisara@kolumbus.fi/T/#t
-and-
https://lore.kernel.org/linux-scsi/20250120194925.44432-1-Kai.Makisara@kolumbus.fi/T/#t

Martin, please merge these patches.

/John

On 1/28/25 9:22 AM, Kai Mäkisara wrote:
> Set tape block size, density and compression to default values when the
> device is reset (either directly or via target, bus or host reset).
> 
> Signed-off-by: Kai Mäkisara <Kai.Makisara@kolumbus.fi>
> ---
>   drivers/scsi/scsi_debug.c | 21 ++++++++++++++++++++-
>   1 file changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> index ceacf38cee71..c5d7e8b59ff2 100644
> --- a/drivers/scsi/scsi_debug.c
> +++ b/drivers/scsi/scsi_debug.c
> @@ -6730,6 +6730,20 @@ static int sdebug_fail_lun_reset(struct scsi_cmnd *cmnd)
>   	return 0;
>   }
>   
> +static void scsi_tape_reset_clear(struct sdebug_dev_info *devip)
> +{
> +	if (sdebug_ptype == TYPE_TAPE) {
> +		int i;
> +
> +		devip->tape_blksize = TAPE_DEF_BLKSIZE;
> +		devip->tape_density = TAPE_DEF_DENSITY;
> +		devip->tape_partition = 0;
> +		devip->tape_dce = 0;
> +		for (i = 0; i < TAPE_MAX_PARTITIONS; i++)
> +			devip->tape_location[i] = 0;
> +	}
> +}
> +
>   static int scsi_debug_device_reset(struct scsi_cmnd *SCpnt)
>   {
>   	struct scsi_device *sdp = SCpnt->device;
> @@ -6743,8 +6757,10 @@ static int scsi_debug_device_reset(struct scsi_cmnd *SCpnt)
>   		sdev_printk(KERN_INFO, sdp, "%s\n", __func__);
>   
>   	scsi_debug_stop_all_queued(sdp);
> -	if (devip)
> +	if (devip) {
>   		set_bit(SDEBUG_UA_POR, devip->uas_bm);
> +		scsi_tape_reset_clear(devip);
> +	}
>   
>   	if (sdebug_fail_lun_reset(SCpnt)) {
>   		scmd_printk(KERN_INFO, SCpnt, "fail lun reset 0x%x\n", opcode);
> @@ -6782,6 +6798,7 @@ static int scsi_debug_target_reset(struct scsi_cmnd *SCpnt)
>   	list_for_each_entry(devip, &sdbg_host->dev_info_list, dev_list) {
>   		if (devip->target == sdp->id) {
>   			set_bit(SDEBUG_UA_BUS_RESET, devip->uas_bm);
> +			scsi_tape_reset_clear(devip);
>   			++k;
>   		}
>   	}
> @@ -6813,6 +6830,7 @@ static int scsi_debug_bus_reset(struct scsi_cmnd *SCpnt)
>   
>   	list_for_each_entry(devip, &sdbg_host->dev_info_list, dev_list) {
>   		set_bit(SDEBUG_UA_BUS_RESET, devip->uas_bm);
> +		scsi_tape_reset_clear(devip);
>   		++k;
>   	}
>   
> @@ -6836,6 +6854,7 @@ static int scsi_debug_host_reset(struct scsi_cmnd *SCpnt)
>   		list_for_each_entry(devip, &sdbg_host->dev_info_list,
>   				    dev_list) {
>   			set_bit(SDEBUG_UA_BUS_RESET, devip->uas_bm);
> +			scsi_tape_reset_clear(devip);
>   			++k;
>   		}
>   	}