Re: [PATCH 2/5] overlay/014: fix test with inodes index enabled

[Eryu Guan <eguan@redhat.com>]

On Tue, Jul 11, 2017 at 10:52:03PM +0300, Amir Goldstein wrote:
> When overlayfs is configured with CONFIG_OVERLAY_FS_INDEX=y,
> workdir from previous overlay mount cannot be reused in a new
> overlay mount that uses a different upper dir.
> 
> Fix the test to use a different workdir when mounting with a
> different upper dir.
> 
> This change has not effect on older kernels and overlay
> configured without CONFIG_OVERLAY_FS_INDEX.
> 
> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
> ---
>  tests/overlay/014 | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/tests/overlay/014 b/tests/overlay/014
> index 40d10f5..6a551b7 100755
> --- a/tests/overlay/014
> +++ b/tests/overlay/014
> @@ -63,12 +63,13 @@ lowerdir1=$OVL_BASE_SCRATCH_MNT/lower1
>  lowerdir2=$OVL_BASE_SCRATCH_MNT/lower2
>  upperdir=$OVL_BASE_SCRATCH_MNT/upper
>  workdir=$OVL_BASE_SCRATCH_MNT/workdir
> -mkdir -p $lowerdir1 $lowerdir2 $upperdir $workdir

I added some comments before creating workdir2 (mostly copied from your
overlay document patch), please let me know if you have different
thoughts.

+# When overlay inode index feature is enabled, using an upper layer path and/or
+# a workdir path that are already used by another overlay mount is not allowed
+# and will fail with EBUSY, so create another workdir for the second overlay
+# mount
> +workdir2=$OVL_BASE_SCRATCH_MNT/workdir2
> +mkdir -p $lowerdir1 $lowerdir2 $upperdir $workdir $workdir2
>  mkdir -p $lowerdir1/testdir/d

Thanks,
Eryu

>  
>  # mount overlay with $lowerdir2 as upperdir, and remove & recreate testdir,
>  # make testdir on $lowerdir2 opaque
> -_overlay_mount_dirs $lowerdir1 $lowerdir2 $workdir $OVL_BASE_SCRATCH_MNT $SCRATCH_MNT
> +_overlay_mount_dirs $lowerdir1 $lowerdir2 $workdir2 $OVL_BASE_SCRATCH_MNT $SCRATCH_MNT
>  rm -rf $SCRATCH_MNT/testdir
>  mkdir -p $SCRATCH_MNT/testdir/visibledir
>  # unmount overlayfs but not base fs
> -- 
> 2.7.4
>