Re: [PATCH 6/6] xfs/535: Fix test to execute in multi-block directory config

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

On Thu, Mar 25, 2021 at 07:38:57PM +0530, Chandan Babu R wrote:
> xfs/535 attempts to create $srcfile and $dstfile after reduce_max_iextents
> error tag is injected. Creation of these files fails when using a multi-block
> directory test configuration because,
> 1. A directory can have a pseudo maximum extent count of 10.
> 2. In the worst case a directory entry creation operation can consume
>    (XFS_DA_NODE_MAXDEPTH + 1 + 1) * (Nr fs blocks in a single directory block)
>    extents.
>    With 1k fs block size and 4k directory block size, this evaluates to,
>    (5 + 1 + 1) * 4
>    = 7 * 4
>    = 28
>    > 10 (Pseudo maximum inode extent count).
> 
> This commit fixes the issue by creating $srcfile and $dstfile before injecting
> reduce_max_iextents error tag.
> 
> Reported-by: Darrick J. Wong <djwong@kernel.org>
> Suggested-by: Darrick J. Wong <djwong@kernel.org>
> Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>

Now on to the xfs/538 regressions! ;)
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  tests/xfs/535     | 11 +++++++++++
>  tests/xfs/535.out |  2 ++
>  2 files changed, 13 insertions(+)
> 
> diff --git a/tests/xfs/535 b/tests/xfs/535
> index 2d82624c..f2a8a3a5 100755
> --- a/tests/xfs/535
> +++ b/tests/xfs/535
> @@ -51,6 +51,9 @@ nr_blks=15
>  srcfile=${SCRATCH_MNT}/srcfile
>  dstfile=${SCRATCH_MNT}/dstfile
>  
> +touch $srcfile
> +touch $dstfile
> +
>  echo "Inject reduce_max_iextents error tag"
>  _scratch_inject_error reduce_max_iextents 1
>  
> @@ -77,10 +80,18 @@ if (( $nextents > 10 )); then
>  	exit 1
>  fi
>  
> +echo "Disable reduce_max_iextents error tag"
> +_scratch_inject_error reduce_max_iextents 0
> +
>  rm $dstfile
>  
>  echo "* Funshare shared extent"
>  
> +touch $dstfile
> +
> +echo "Inject reduce_max_iextents error tag"
> +_scratch_inject_error reduce_max_iextents 1
> +
>  echo "Share the extent with \$dstfile"
>  _reflink $srcfile $dstfile >> $seqres.full
>  
> diff --git a/tests/xfs/535.out b/tests/xfs/535.out
> index 4383e921..8f600272 100644
> --- a/tests/xfs/535.out
> +++ b/tests/xfs/535.out
> @@ -6,7 +6,9 @@ Create a $srcfile having an extent of length 15 blocks
>  Share the extent with $dstfile
>  Buffered write to every other block of $dstfile's shared extent
>  Verify $dstfile's extent count
> +Disable reduce_max_iextents error tag
>  * Funshare shared extent
> +Inject reduce_max_iextents error tag
>  Share the extent with $dstfile
>  Funshare every other block of $dstfile's shared extent
>  Verify $dstfile's extent count
> -- 
> 2.29.2
>