Re: [PATCH 2/3] fstests: add helper _require_xfs_io_shutdown

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

On Mon, Jun 09, 2025 at 05:19:14PM +0200, Amir Goldstein wrote:
> Requirements for tests that shutdown fs using "xfs_io -c shutdown".
> The requirements are stricter than the requirement for tests that
> shutdown fs using _scratch_shutdown helper.
> 
> Generally, with overlay fs, tests can do _scratch_shutdown, but not
> xfs_io -c shutdown.
> 
> Encode this stricter requirement in helper _require_xfs_io_shutdown
> and use it in test generic/623, to express that it cannot run on
> overalyfs.
> 
> Reported-by: André Almeida <andrealmeid@igalia.com>
> Link: https://lore.kernel.org/linux-fsdevel/20250521-ovl_ro-v1-1-2350b1493d94@igalia.com/
> Signed-off-by: Amir Goldstein <amir73il@gmail.com>

Makes sense to me, assuming you don't want to try to integrate the 'open
shutdown handle' dance into this test.

ioargs=(-x -c "mmap 0 4k" -c "mwrite 0 4k")
case "$FSTYP" in
overlayfs)
	ioargs+=(-c "open $(_scratch_shutdown_handle)" -c 'shutdown -f ' -c close)
	;;
*)
	ioargs+=(-c shutdown)
	;;
esac
ioargs+=(-c fsync -c "mwrite 0 4k" $file)

$XFS_IO_PROG "${ioargs[@]}" | _filter_xfs_io

(Though I don't know if you actually tried that and it didn't work, or
maybe overlayfs mmap is weird, etc...)

--D

> ---
>  common/rc         | 21 +++++++++++++++++++++
>  tests/generic/623 |  2 +-
>  2 files changed, 22 insertions(+), 1 deletion(-)
> 
> diff --git a/common/rc b/common/rc
> index d9a8b52e..21899a4a 100644
> --- a/common/rc
> +++ b/common/rc
> @@ -616,6 +616,27 @@ _scratch_shutdown_and_syncfs()
>  	fi
>  }
>  
> +# Requirements for tests that shutdown fs using "xfs_io -c shutdown".
> +# The requirements are stricter than the requirement for tests that
> +# shutdown fs using _scratch_shutdown helper.
> +# Generally, with overlay fs, test can do _scratch_shutdown, but not
> +# xfs_io -c shutdown.
> +# It is possible, but not trivial, to execute "xfs_io -c shutdown" as part
> +# of a command sequence when shutdown ioctl is to be performed on the base fs
> +# (i.e. on an alternative _scratch_shutdown_handle path) as the example code
> +# in _scratch_shutdown_and_syncfs() does.
> +# A test that open codes this pattern can relax the _require_xfs_io_shutdown
> +# requirement down to _require_scratch_shutdown.
> +_require_xfs_io_shutdown()
> +{
> +	if [ _scratch_shutdown_handle != $SCRATCH_MNT ]; then
> +		# Most likely overlayfs
> +		_notrun "xfs_io -c shutdown not supported on $FSTYP"
> +	fi
> +	_require_xfs_io_command "shutdown"
> +	_require_scratch_shutdown
> +}
> +
>  _move_mount()
>  {
>  	local mnt=$1
> diff --git a/tests/generic/623 b/tests/generic/623
> index b97e2adb..f546d529 100755
> --- a/tests/generic/623
> +++ b/tests/generic/623
> @@ -15,7 +15,7 @@ _begin_fstest auto quick shutdown mmap
>  	"xfs: restore shutdown check in mapped write fault path"
>  
>  _require_scratch_nocheck
> -_require_scratch_shutdown
> +_require_xfs_io_shutdown
>  
>  _scratch_mkfs &>> $seqres.full
>  _scratch_mount
> -- 
> 2.34.1
> 
>