On Mon, Jul 22, 2019 at 08:02:27AM +0300, Amir Goldstein wrote:
> This is needed to support the kernel regression fix commit 0be0bfd2de9d
> ("ovl: fix regression caused by overlapping layers detection").
>
> Overlayfs mount is not supposed to fail due to upper/work dir in-use
> by other mount unless option index=on is enabled.
Sorry for the late review.. Looks like this patch only mount overlay
with "index=on" explicitly, but doesn't check that mount succeeds when
"index=off", which is really regressed. Do we need to add more
"index=off" tests to ensure we allow re-use upperdir?
Thanks,
Eryu
>
> Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
> ---
>
> Eryu,
>
> With this applied, test is expected to fail on upstream kernel,
> because upstream kernel has a regression.
>
> The kernel fix commit is on Miklos' overlayfs-next branch.
>
> Thanks,
> Amir.
>
> tests/overlay/065 | 26 ++++++++++++++++----------
> tests/overlay/065.out | 4 ++--
> 2 files changed, 18 insertions(+), 12 deletions(-)
>
> diff --git a/tests/overlay/065 b/tests/overlay/065
> index abfc6737..a75a9a10 100755
> --- a/tests/overlay/065
> +++ b/tests/overlay/065
> @@ -13,9 +13,14 @@
> #
> # Overlapping layers on mount or lookup results in ELOOP.
> # Overlapping lowerdir with other mount upperdir/workdir
> -# result in EBUSY.
> +# result in EBUSY (if index=on is used).
> #
> -# Kernel patch "ovl: detect overlapping layers" is needed to pass the test.
> +# This is a regression test for kernel commit:
> +#
> +# 146d62e5a586 "ovl: detect overlapping layers"
> +#
> +# and its followup fix commit:
> +# 0be0bfd2de9d "ovl: fix regression caused by overlapping layers detection"
> #
> seq=`basename $0`
> seqres=$RESULT_DIR/$seq
> @@ -46,6 +51,7 @@ _supported_os Linux
> # Use non-default scratch underlying overlay dirs, we need to check
> # them explicity after test.
> _require_scratch_nocheck
> +_require_scratch_feature index
>
> # Remove all files from previous tests
> _scratch_mkfs
> @@ -61,10 +67,10 @@ mnt2=$basedir/mnt.2
>
> mkdir -p $lowerdir/lower $upperdir $workdir
>
> -# Try to mount an overlay with the same upperdir/lowerdir - expect EBUSY
> +# Try to mount an overlay with the same upperdir/lowerdir - expect ELOOP
> echo Conflicting upperdir/lowerdir
> _overlay_scratch_mount_dirs $upperdir $upperdir $workdir \
> - 2>&1 | _filter_busy_mount
> + 2>&1 | _filter_error_mount
> $UMOUNT_PROG $SCRATCH_MNT 2>/dev/null
>
> # Use new upper/work dirs for each test to avoid ESTALE errors
> @@ -72,11 +78,11 @@ $UMOUNT_PROG $SCRATCH_MNT 2>/dev/null
> rm -rf $upperdir $workdir
> mkdir $upperdir $workdir
>
> -# Try to mount an overlay with the same workdir/lowerdir - expect EBUSY
> +# Try to mount an overlay with the same workdir/lowerdir - expect ELOOP
> # because $workdir/work overlaps with lowerdir
> echo Conflicting workdir/lowerdir
> _overlay_scratch_mount_dirs $workdir $upperdir $workdir \
> - 2>&1 | _filter_busy_mount
> + -oindex=off 2>&1 | _filter_error_mount
> $UMOUNT_PROG $SCRATCH_MNT 2>/dev/null
>
> rm -rf $upperdir $workdir
> @@ -126,20 +132,20 @@ rm -rf $upperdir2 $workdir2
> mkdir -p $upperdir2 $workdir2 $mnt2
>
> # Try to mount an overlay with layers overlapping with another overlayfs
> -# upperdir - expect EBUSY
> +# upperdir - expect EBUSY with index=on
> echo Overlapping with upperdir of another instance
> _overlay_scratch_mount_dirs $upperdir/upper $upperdir2 $workdir2 \
> - 2>&1 | _filter_busy_mount
> + -oindex=on 2>&1 | _filter_busy_mount
> $UMOUNT_PROG $SCRATCH_MNT 2>/dev/null
>
> rm -rf $upperdir2 $workdir2
> mkdir -p $upperdir2 $workdir2
>
> # Try to mount an overlay with layers overlapping with another overlayfs
> -# workdir - expect EBUSY
> +# workdir - expect EBUSY with index=on
> echo Overlapping with workdir of another instance
> _overlay_scratch_mount_dirs $workdir/work $upperdir2 $workdir2 \
> - 2>&1 | _filter_busy_mount
> + -oindex=on 2>&1 | _filter_busy_mount
> $UMOUNT_PROG $SCRATCH_MNT 2>/dev/null
>
> # Move upper layer root into lower layer after mount
> diff --git a/tests/overlay/065.out b/tests/overlay/065.out
> index 0260327c..c63d4df8 100644
> --- a/tests/overlay/065.out
> +++ b/tests/overlay/065.out
> @@ -1,8 +1,8 @@
> QA output created by 065
> Conflicting upperdir/lowerdir
> -mount: device already mounted or mount point busy
> +mount: Too many levels of symbolic links
> Conflicting workdir/lowerdir
> -mount: device already mounted or mount point busy
> +mount: Too many levels of symbolic links
> Overlapping upperdir/lowerdir
> mount: Too many levels of symbolic links
> Conflicting lower layers
> --
> 2.17.1
>
