Re: [PATCH 3/4] generic/570: fix regression when SCRATCH_DEV is still formatted

[Eryu Guan <guan@eryu.me>]

On Tue, Jul 27, 2021 at 05:09:54PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
> 
> Newer versions of mkswap (or at least the one in util-linux 2.34)
> complain to stderr when they're formatting over a device that seems to
> contain existing data:
> 
>     mkswap: /dev/sdf: warning: wiping old btrfs signature.
> 
> This is harmless (since the swap image does get written!) but the extra
> golden output is flagged as a regression.  Update the mkswap usage in
> this test to dump the stderr output to $seqres.full, and complain if the
> exit code is nonzero.
> 
> This fixes a regression that the author noticed when testing btrfs and
> generic/507 and generic/570 run sequentially.  generic/507 calls
> _require_scratch_shutdown to see if the shutdown call is supported.
> btrfs does not support that, so the test is _notrun.  This leaves the
> scratch filesystem mounted, causing the _try_wipe_scratch_devs between
> tests to fail.  When g/570 starts up, the scratch device still contains

Won't your previous patch "check: don't leave the scratch filesystem
mounted after _notrun" fix this issue as well? As _notrun won't leaves
scratch dev mounted & unwiped after that patch. Would you please confirm?

Thanks,
Eryu

> leftovers from the failed attempt to run g/507, which is why the mkswap
> command outputs the above warning.
> 
> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> ---
>  tests/generic/570 |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> 
> diff --git a/tests/generic/570 b/tests/generic/570
> index 7d03acfe..02c1d333 100755
> --- a/tests/generic/570
> +++ b/tests/generic/570
> @@ -27,7 +27,7 @@ _require_scratch_nocheck
>  _require_block_device $SCRATCH_DEV
>  test -e /dev/snapshot && _notrun "userspace hibernation to swap is enabled"
>  
> -$MKSWAP_PROG "$SCRATCH_DEV" >> $seqres.full
> +$MKSWAP_PROG -f "$SCRATCH_DEV" &>> $seqres.full || echo "mkswap failed?"
>  
>  # Can you modify the swap dev via previously open file descriptors?
>  for verb in 1 2 3 4; do