Re: [ndctl PATCH] test/rescan-partitions.sh: refine search for created partition

["Verma, Vishal L" <vishal.l.verma@intel.com>]

On Wed, 2024-08-28 at 12:26 -0700, alison.schofield@intel.com wrote:
> From: Alison Schofield <alison.schofield@intel.com>
> 
> Unit test rescan-partitions.sh can fail because the grep test looking
> for the expected partition is overly broad and can match multiple
> pmem devices.
> 
> /root/ndctl/build/meson-logs/testlog.txt reports this failure:
> test/rescan-partitions.sh: failed at line 50
> 
> An example of an improper grep is:
> 'pmem10 pmem12 pmem1p1' when only 'pmem1p1' was expected
> 
> Replace the faulty grep with a query of the lsblk JSON output that
> examines the children of this blockdev only and matches on size.
> 
> This type of pesky issue is probably arising as the unit tests are
> being run in more complex environments and may also be due to other
> unit tests not properly cleaning up after themselves. No matter the
> cause this change makes this test more robust and that's a good
> thing!
> 
> Reported-by: Ira Weiny <ira.weiny@intel.com>
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>
> ---
>  test/rescan-partitions.sh | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/test/rescan-partitions.sh b/test/rescan-partitions.sh
> index 51bbd731fb55..ccb542cb2f68 100755
> --- a/test/rescan-partitions.sh
> +++ b/test/rescan-partitions.sh
> @@ -24,6 +24,7 @@ check_min_kver "4.16" || do_skip "may not contain
> fixes for partition rescanning
>  
>  check_prereq "parted"
>  check_prereq "blockdev"
> +check_prereq "jq"
>  
>  test_mode()
>  {
> @@ -46,7 +47,10 @@ test_mode()
>  	sleep 1
>  	blockdev --rereadpt /dev/$blockdev
>  	sleep 1
> -	partdev="$(grep -Eo "${blockdev}.+" /proc/partitions)"
> +	partdev=$(lsblk -J -o NAME,SIZE /dev/$blockdev |
> +		jq -r '.blockdevices[] | .children[] |
> +		select(.size == "9M") | .name')

Hm slight reaction to the size == 9M check that wasn't there before.

Would it be better to just use .children[0].name instead of looking for
a specific 9M sized partition? May be more robust if the size ever
changes for some reason.

Otherwise looks good,

Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>