Re: [PATCH 4/7] reflink: fix space consumption tests

[Eryu Guan <eguan@redhat.com>]

On Sun, Dec 11, 2016 at 01:53:10PM -0800, Darrick J. Wong wrote:
> Some of the tests try to check that we can't COW when we're out of
> space, but some tricky filesystems make this hard because writing N
> blocks doesn't increase used blocks by N....
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
>  common/populate   |   14 ++++++++++++++
>  tests/generic/171 |    5 ++---
>  tests/generic/173 |    5 ++---
>  tests/generic/174 |    5 ++---
>  tests/generic/282 |    3 +--
>  5 files changed, 21 insertions(+), 11 deletions(-)
> 
> 
> diff --git a/common/populate b/common/populate
> index d0003c5..9811d21 100644
> --- a/common/populate
> +++ b/common/populate
> @@ -30,6 +30,20 @@ _require_xfs_db_blocktrash_z_command() {
>  	$XFS_DB_PROG -x -f -c 'blocktrash -z' "${TEST_DEV}" | grep -q 'nothing on stack' || _notrun "blocktrash -z not supported"
>  }
>  
> +# Eat free space until we can't anymore.
> +_consume_free_space() {
> +	dir=$1
> +
> +	old_nr_free=0
> +	nr_free=$(stat -f -c '%f' $dir)
> +	x=0
> +	while [ $nr_free -gt 0 ] && [ $old_nr_free != $nr_free ]; do
> +		$XFS_IO_PROG -f -c "pwrite -b 4194304 0 $((blksz * nr_free))" $dir/eat_my_space.$((x++))

blksz not defined in the function.

Xiaoguang Wang did something similar back in Nov. and I'm still queuing
his patch. (His 1/2 patch conflicts with your scrub/repair patchset and
it might be easier for you to let your patches go first.)

generic: make 17[1-4] work well when btrfs compression is enabled
https://patchwork.kernel.org/patch/9408451/

Does this patch work for you? If so, perhaps you only need to update
generic/282 using the "_fill_fs" helper?

Thanks,
Eryu