Re: [PATCH v2 3/4] generic/{455,457,482}: make dmlogwrites tests work on bcachefs

[Eryu Guan <guan@eryu.me>]

On Tue, May 25, 2021 at 06:19:54PM -0400, Kent Overstreet wrote:
> bcachefs has log structured btree nodes, in addition to a regular
> journal, which means that unless we replay to markers in the log in the
> same order that they happened and are careful to avoid writing in
> between replaying to different events - we need to wipe and start fresh
> each time.
> 
> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
> ---
>  tests/generic/455 | 14 ++++++++++++++
>  tests/generic/457 | 14 ++++++++++++++
>  tests/generic/482 | 27 ++++++++++++++++++++-------
>  3 files changed, 48 insertions(+), 7 deletions(-)
> 
> diff --git a/tests/generic/455 b/tests/generic/455
> index 5b4b242e74..6dc46c3c72 100755
> --- a/tests/generic/455
> +++ b/tests/generic/455
> @@ -35,6 +35,17 @@ _require_dm_target thin-pool
>  
>  rm -f $seqres.full
>  
> +_reset_dmthin()
> +{
> +    # With bcachefs, we need to wipe and start fresh every time we replay to a
> +    # different point in time - if we see metadata from a future point in time,
> +    # or an unrelated mount, bcachefs will get confused:
> +    if [ "$FSTYP" = "bcachefs" ]; then
> +	_dmthin_cleanup
> +	_dmthin_init $devsize $devsize $csize $lowspace
> +    fi
> +}

I think we probably could make it a common helper, and currently only
bcachefs needs reset, and more log structured filesystems may be
supported in the future.

Thanks,
Eryu

> +
>  check_files()
>  {
>  	local name=$1
> @@ -44,6 +55,7 @@ check_files()
>  		local filename=$(basename $i)
>  		local mark="${filename##*.}"
>  		echo "checking $filename" >> $seqres.full
> +		_reset_dmthin
>  		_log_writes_replay_log $filename $DMTHIN_VOL_DEV
>  		_dmthin_mount
>  		local expected_md5=$(_md5_checksum $i)
> @@ -101,6 +113,7 @@ _dmthin_check_fs
>  
>  # check pre umount
>  echo "checking pre umount" >> $seqres.full
> +_reset_dmthin
>  _log_writes_replay_log last $DMTHIN_VOL_DEV
>  _dmthin_mount
>  _dmthin_check_fs
> @@ -111,6 +124,7 @@ done
>  
>  # Check the end
>  echo "checking post umount" >> $seqres.full
> +_reset_dmthin
>  _log_writes_replay_log end $DMTHIN_VOL_DEV
>  _dmthin_mount
>  for j in `seq 0 $((NUM_FILES-1))`; do
> diff --git a/tests/generic/457 b/tests/generic/457
> index ddbd90cf0c..f17d4e4430 100755
> --- a/tests/generic/457
> +++ b/tests/generic/457
> @@ -37,6 +37,17 @@ _require_dm_target thin-pool
>  
>  rm -f $seqres.full
>  
> +_reset_dmthin()
> +{
> +    # With bcachefs, we need to wipe and start fresh every time we replay to a
> +    # different point in time - if we see metadata from a future point in time,
> +    # or an unrelated mount, bcachefs will get confused:
> +    if [ "$FSTYP" = "bcachefs" ]; then
> +	_dmthin_cleanup
> +	_dmthin_init $devsize $devsize $csize $lowspace
> +    fi
> +}
> +
>  check_files()
>  {
>  	local name=$1
> @@ -46,6 +57,7 @@ check_files()
>  		local filename=$(basename $i)
>  		local mark="${filename##*.}"
>  		echo "checking $filename" >> $seqres.full
> +		_reset_dmthin
>  		_log_writes_replay_log $filename $DMTHIN_VOL_DEV
>  		_dmthin_mount
>  		local expected_md5=$(_md5_checksum $i)
> @@ -105,6 +117,7 @@ _dmthin_check_fs
>  
>  # check pre umount
>  echo "checking pre umount" >> $seqres.full
> +_reset_dmthin
>  _log_writes_replay_log last $DMTHIN_VOL_DEV
>  _dmthin_mount
>  _dmthin_check_fs
> @@ -115,6 +128,7 @@ done
>  
>  # Check the end
>  echo "checking post umount" >> $seqres.full
> +_reset_dmthin
>  _log_writes_replay_log end $DMTHIN_VOL_DEV
>  _dmthin_mount
>  for j in `seq 0 $((NUM_FILES-1))`; do
> diff --git a/tests/generic/482 b/tests/generic/482
> index 86941e8468..3cbe187f2e 100755
> --- a/tests/generic/482
> +++ b/tests/generic/482
> @@ -77,16 +77,29 @@ prev=$(_log_writes_mark_to_entry_number mkfs)
>  cur=$(_log_writes_find_next_fua $prev)
>  [ -z "$cur" ] && _fail "failed to locate next FUA write"
>  
> +if [ "$FSTYP" = "bcachefs" ]; then
> +    _dmthin_cleanup
> +    _dmthin_init $devsize $devsize $csize $lowspace
> +fi
> +
>  while [ ! -z "$cur" ]; do
>  	_log_writes_replay_log_range $cur $DMTHIN_VOL_DEV >> $seqres.full
>  
> -	# Here we need extra mount to replay the log, mainly for journal based
> -	# fs, as their fsck will report dirty log as error.
> -	# We don't care to preserve any data on the replay dev, as we can replay
> -	# back to the point we need, and in fact sometimes creating/deleting
> -	# snapshots repeatedly can be slower than replaying the log.
> -	_dmthin_mount
> -	_dmthin_check_fs
> +	if [ "$FSTYP" = "bcachefs" ]; then
> +	    # bcachefs will get confused if fsck does writes to replay the log,
> +	    # but then we replay writes from an earlier point in time on the
> +	    # same fs - but  fsck in -n mode won't do any writes:
> +	    _check_scratch_fs -n $DMTHIN_VOL_DEV
> +	else
> +	    # Here we need extra mount to replay the log, mainly for journal based
> +	    # fs, as their fsck will report dirty log as error.
> +	    # We don't care to preserve any data on the replay dev, as we can replay
> +	    # back to the point we need, and in fact sometimes creating/deleting
> +	    # snapshots repeatedly can be slower than replaying the log.
> +
> +	    _dmthin_mount
> +	    _dmthin_check_fs
> +	fi
>  
>  	prev=$cur
>  	cur=$(_log_writes_find_next_fua $(($cur + 1)))
> -- 
> 2.32.0.rc0