Re: [PATCH] generic/108: use sysfs values for logical,physical block size in scsi_debug

["Darrick J. Wong" <djwong@kernel.org>]

On Wed, Mar 02, 2022 at 02:59:47AM +0530, Nitesh Shetty wrote:
> scsi_debug device used for test, is created with assumption of 512 bytes
> logical and physical block size.
> This causes error in lvcreate step, when SCRATCH_DEV device lba is not
> 512 bytes. This can be solved by reading block size from sysfs of device.
> If sysfs is missing fallback to 512 bytes as default.
> 
> Signed-off-by: Nitesh Shetty <nj.shetty@samsung.com>
> ---
>  tests/generic/108 | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/generic/108 b/tests/generic/108
> index ad43269f..db0e9bd0 100755
> --- a/tests/generic/108
> +++ b/tests/generic/108
> @@ -42,8 +42,11 @@ _require_non_zoned_device $SCRATCH_DEV
>  lvname=lv_$seq
>  vgname=vg_$seq
>  
> +physical=$(cat /sys/block/$(_short_dev $SCRATCH_DEV)/queue/physical_block_size)
> +logical=$(cat /sys/block/$(_short_dev $SCRATCH_DEV)/queue/logical_block_size)

This causes a regression if $SCRATCH_DEV is not a raw block device:

# SCRATCH_DEV=/dev/sda4 ./check generic/108
...
--- generic/108.out
+++ generic/108.out.bad
@@ -1,2 +1,4 @@
 QA output created by 108
+cat: /sys/block/sda4/queue/physical_block_size: No such file or directory
+cat: /sys/block/sda4/queue/logical_block_size: No such file or directory
 fsync: Input/output error

--D

> +
>  # _get_scsi_debug_dev returns a scsi debug device with 128M in size by default
> -SCSI_DEBUG_DEV=`_get_scsi_debug_dev 512 512 0 300`
> +SCSI_DEBUG_DEV=`_get_scsi_debug_dev ${physical:-512} ${logical:-512} 0 300`
>  test -b "$SCSI_DEBUG_DEV" || _notrun "Failed to initialize scsi debug device"
>  echo "SCSI debug device $SCSI_DEBUG_DEV" >>$seqres.full
>  
> 
> base-commit: 2ea74ba4e70b546279896e2a733c8c7f4b206193
> -- 
> 2.25.1
>