[PATCH 0/2] fstests: fix overlay test failure over ext4

[PATCH 0/2] fstests: fix overlay test failure over ext4

[Amir Goldstein]

Eryu,

As I reported earlier, test generic/009 was failing ./check -overlay
run due to a test bug. The test belongs to a class of tests that have
explicit check for a certain $FSTYP, which does not apply when FSTYP is
overlay.

I ran all the tests that check for FSTYP = ext4 with overlay over ext4
and all the tests that check for FSTYP = xfs with overlay over xfs.
generic/009 was the only test that failed because of the exlicit check.
The rest of the tests either passes or did not run for a good reason.

Strangely, tests which _require_seek_data_hole(), that has the exact same
check as generic/009 didn't fail with overlay over ext4. In fact, those
tests also did not with with bare ext4 even when I removed the call
to _ext4_disable_extent_zeroout() from _require_seek_data_hole()???

I tried to come up with a more generic solution, but didn't like any
ideas I had, so I ended up fixing generic/009 in place in the hope that
you either accept it as is or propose a better solution.

The fix depends on the user either setting FSTYP=ext4 in a config file
or setting the variable OVL_BASE_FSTYP before running the test.
I will soon send a patch for kvm-xfstests to Ted that does the latter.

Thanks,
Amir.

Amir Goldstein (2):
  overlay: do not set OVL_BASE_FSTYP value to "overlay"
  generic/009: fix test failure with overlay over ext4

 common/config     | 2 +-
 tests/generic/009 | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

-- 
2.7.4

[PATCH 1/2] overlay: do not set OVL_BASE_FSTYP value to "overlay"

[Amir Goldstein]

The purpose of OVL_BASE_FSTYP is to store the value of FSTYP that is
found in a host config file section.

When there is no host config file or if user sets FSTYP=overlay in config
file, it makes no sense to store the value "overlay" in OVL_BASE_FSTYP
and it is better to leave it empty or leave its current value in tact.

This allows user to set OVL_BASE_FSTYP in config file or before running
the test to support queries about base fs, such as
_require_metadata_journaling, even when running an overlay test.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
 common/config | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/common/config b/common/config
index 2f1f272..d85519a 100644
--- a/common/config
+++ b/common/config
@@ -530,7 +530,7 @@ _overlay_config_override()
 	[ -b "$TEST_DEV" ] || return 0
 
 	# Config file may specify base fs type, but we obay -overlay flag
-	export OVL_BASE_FSTYP="$FSTYP"
+	[ "$FSTYP" == overlay ] || export OVL_BASE_FSTYP="$FSTYP"
 	export FSTYP=overlay
 
 	# Store original base fs vars
-- 
2.7.4

[PATCH 2/2] generic/009: fix test failure with overlay over ext4

[Amir Goldstein]

When running test with overlayfs and ext4 as base fs, we need to
disable extent zeroout on the underlying base fs.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---

Eryu,

Suggestions for a cleaner approach are welcome.

Thanks,
Amir.

 tests/generic/009 | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tests/generic/009 b/tests/generic/009
index fa6ef46..a4f56d0 100755
--- a/tests/generic/009
+++ b/tests/generic/009
@@ -39,6 +39,9 @@ testfile=$TEST_DIR/009.$$
 if [ "$FSTYP" = "ext4" ]; then
 	_ext4_disable_extent_zeroout
 fi
+if [ "$FSTYP" = "overlay" -a "$OVL_BASE_FSTYP" = "ext4" ]; then
+	_ext4_disable_extent_zeroout "$OVL_BASE_TEST_DEV"
+fi
 
 # When PAGE_SIZE > 4096 some filesystems extent layout is different so
 # it would not match the output.
-- 
2.7.4

Re: [PATCH 2/2] generic/009: fix test failure with overlay over ext4

[Eryu Guan]

On Mon, Aug 27, 2018 at 09:29:26PM +0300, Amir Goldstein wrote:
> When running test with overlayfs and ext4 as base fs, we need to
> disable extent zeroout on the underlying base fs.
> 
> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
> ---
> 
> Eryu,
> 
> Suggestions for a cleaner approach are welcome.

I thought about it too but came out with no better ideas, I think I'll
just take your patches as-is.


Thanks,
Eryu

> 
> Thanks,
> Amir.
> 
>  tests/generic/009 | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/tests/generic/009 b/tests/generic/009
> index fa6ef46..a4f56d0 100755
> --- a/tests/generic/009
> +++ b/tests/generic/009
> @@ -39,6 +39,9 @@ testfile=$TEST_DIR/009.$$
>  if [ "$FSTYP" = "ext4" ]; then
>  	_ext4_disable_extent_zeroout
>  fi
> +if [ "$FSTYP" = "overlay" -a "$OVL_BASE_FSTYP" = "ext4" ]; then
> +	_ext4_disable_extent_zeroout "$OVL_BASE_TEST_DEV"
> +fi
>  
>  # When PAGE_SIZE > 4096 some filesystems extent layout is different so
>  # it would not match the output.
> -- 
> 2.7.4
>