Re: [PATCH v3 3/3] generic/470: use thin volume for dmlogwrites target device

[Amir Goldstein <amir73il@gmail.com>]

On Tue, Sep 1, 2020 at 4:48 PM Brian Foster <bfoster@redhat.com> wrote:
>
> dmlogwrites support for XFS depends on discard zeroing support of
> the intended target device. Update the test to use a thin volume and
> allow it to run consistently and reliably on XFS.
>
> Signed-off-by: Brian Foster <bfoster@redhat.com>
> ---
Reviewed-by: Amir Goldstein <amir73il@gmail.com>

>  tests/generic/470 | 23 +++++++++++++++++------
>  1 file changed, 17 insertions(+), 6 deletions(-)
>
> diff --git a/tests/generic/470 b/tests/generic/470
> index fd6da563..c77499a2 100755
> --- a/tests/generic/470
> +++ b/tests/generic/470
> @@ -20,12 +20,14 @@ _cleanup()
>  {
>         cd /
>         _log_writes_cleanup
> +       _dmthin_cleanup
>         rm -f $tmp.*
>  }
>
>  # get standard environment, filters and checks
>  . ./common/rc
>  . ./common/filter
> +. ./common/dmthin
>  . ./common/dmlogwrites
>
>  # remove previous $seqres.full before test
> @@ -34,12 +36,21 @@ rm -f $seqres.full
>  # real QA test starts here
>  _supported_fs generic
>  _supported_os Linux
> -_require_scratch
> +_require_scratch_nocheck
>  _require_log_writes_dax_mountopt "dax"
> +_require_dm_target thin-pool
>  _require_xfs_io_command "mmap" "-S"
>  _require_xfs_io_command "log_writes"
>
> -_log_writes_init $SCRATCH_DEV
> +devsize=$((1024*1024*200 / 512))        # 200m phys/virt size
> +csize=$((1024*64 / 512))                # 64k cluster size
> +lowspace=$((1024*1024 / 512))           # 1m low space threshold
> +
> +# Use a thin device to provide deterministic discard behavior. Discards are used
> +# by the log replay tool for fast zeroing to prevent out-of-order replay issues.
> +_dmthin_init $devsize $devsize $csize $lowspace
> +
> +_log_writes_init $DMTHIN_VOL_DEV
>  _log_writes_mkfs >> $seqres.full 2>&1
>  _log_writes_mount -o dax
>
> @@ -52,14 +63,14 @@ $XFS_IO_PROG -t -c "truncate $LEN" -c "mmap -S 0 $LEN" -c "mwrite 0 $LEN" \
>  # Unmount the scratch dir and tear down the log writes target
>  _log_writes_unmount
>  _log_writes_remove
> -_check_scratch_fs
> +_dmthin_check_fs
>
>  # destroy previous filesystem so we can be sure our rebuild works
> -_scratch_mkfs >> $seqres.full 2>&1
> +_mkfs_dev $DMTHIN_VOL_DEV >> $seqres.full 2>&1
>
>  # check pre-unmap state
> -_log_writes_replay_log preunmap $SCRATCH_DEV
> -_scratch_mount
> +_log_writes_replay_log preunmap $DMTHIN_VOL_DEV
> +_dmthin_mount
>
>  # We should see $SCRATCH_MNT/test as having 1 MiB in block allocations
>  du -sh $SCRATCH_MNT/test | _filter_scratch | _filter_spaces
> --
> 2.25.4
>