[PATCH v2] fstests: btrfs/057: Fix false alerts due to orphan files

[PATCH v2] fstests: btrfs/057: Fix false alerts due to orphan files

[Qu Wenruo]

For any recent kernel, there is a chance that btrfs/057 reports false
errors.

The false error would look like:
  btrfs/057 4s ... - output mismatch (see /home/adam/xfstests-dev/results//btrfs/057.out.bad)
      --- tests/btrfs/057.out	2017-08-21 09:25:33.166666666 +0800
      +++ /home/adam/xfstests-dev/results//btrfs/057.out.bad	2018-10-29 14:07:28.443651293 +0800
      @@ -1,3 +1,3 @@
       QA output created by 057
       4096 4096
      -4096 4096
      +28672 28672

This is related to the fact that "btrfs subvolume sync" (or
vanilla sync) will not ensure orphan (unlinked but still exist) files to
be removed.

In fact, for that false error case, if inspecting the fs after umount,
its qgroup number is correct and btrfs check won't report qgroup error.

To fix the false alerts, just skip any manual qgroup number comparison,
and let fsck done after the test case to detect problem.

This also elimiate the necessary of using specified mount and mkfs
option, allowing us to improve coverage.

Reported-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
---
Changelog:
v2:
  Update commit message to show this is a long existing bug.
---
 tests/btrfs/057     | 17 ++++-------------
 tests/btrfs/057.out |  3 +--
 2 files changed, 5 insertions(+), 15 deletions(-)

diff --git a/tests/btrfs/057 b/tests/btrfs/057
index b019f4e1e054..0b5a36d34852 100755
--- a/tests/btrfs/057
+++ b/tests/btrfs/057
@@ -33,12 +33,9 @@ _require_scratch
 rm -f $seqres.full
 
 # use small leaf size to get higher btree height.
-run_check _scratch_mkfs "-b 1g --nodesize 4096"
+run_check _scratch_mkfs "-b 1g"
 
-# inode cache is saved in the FS tree itself for every
-# individual FS tree,that affects the sizes reported by qgroup show
-# so we need to explicitly turn it off to get consistent values.
-_scratch_mount "-o noinode_cache"
+_scratch_mount
 
 # -w ensures that the only ops are ones which cause write I/O
 run_check $FSSTRESS_PROG -d $SCRATCH_MNT -w -p 5 -n 1000 \
@@ -53,14 +50,8 @@ run_check $FSSTRESS_PROG -d $SCRATCH_MNT/snap1 -w -p 5 -n 1000 \
 _run_btrfs_util_prog quota enable $SCRATCH_MNT
 _run_btrfs_util_prog quota rescan -w $SCRATCH_MNT
 
-# remove all file/dir other than subvolume
-rm -rf $SCRATCH_MNT/snap1/* >& /dev/null
-rm -rf $SCRATCH_MNT/p* >& /dev/null
-
-_run_btrfs_util_prog filesystem sync $SCRATCH_MNT
-units=`_btrfs_qgroup_units`
-$BTRFS_UTIL_PROG qgroup show $units $SCRATCH_MNT | $SED_PROG -n '/[0-9]/p' \
-	| $AWK_PROG '{print $2" "$3}'
+echo "Silence is golden"
+# btrfs check will detect any qgroup number mismatch.
 
 status=0
 exit
diff --git a/tests/btrfs/057.out b/tests/btrfs/057.out
index 60cb92d0926c..185023c79961 100644
--- a/tests/btrfs/057.out
+++ b/tests/btrfs/057.out
@@ -1,3 +1,2 @@
 QA output created by 057
-4096 4096
-4096 4096
+Silence is golden
-- 
2.19.1

Re: [PATCH v2] fstests: btrfs/057: Fix false alerts due to orphan files

[Nikolay Borisov]

On 30.10.18 г. 11:07 ч., Qu Wenruo wrote:
> For any recent kernel, there is a chance that btrfs/057 reports false
> errors.
> 
> The false error would look like:
>   btrfs/057 4s ... - output mismatch (see /home/adam/xfstests-dev/results//btrfs/057.out.bad)
>       --- tests/btrfs/057.out	2017-08-21 09:25:33.166666666 +0800
>       +++ /home/adam/xfstests-dev/results//btrfs/057.out.bad	2018-10-29 14:07:28.443651293 +0800
>       @@ -1,3 +1,3 @@
>        QA output created by 057
>        4096 4096
>       -4096 4096
>       +28672 28672
> 
> This is related to the fact that "btrfs subvolume sync" (or
> vanilla sync) will not ensure orphan (unlinked but still exist) files to
> be removed.
> 
> In fact, for that false error case, if inspecting the fs after umount,
> its qgroup number is correct and btrfs check won't report qgroup error.
> 
> To fix the false alerts, just skip any manual qgroup number comparison,
> and let fsck done after the test case to detect problem.
> 
> This also elimiate the necessary of using specified mount and mkfs
> option, allowing us to improve coverage.
> 
> Reported-by: Nikolay Borisov <nborisov@suse.com>
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> ---
> Changelog:
> v2:
>   Update commit message to show this is a long existing bug.
> ---
>  tests/btrfs/057     | 17 ++++-------------
>  tests/btrfs/057.out |  3 +--
>  2 files changed, 5 insertions(+), 15 deletions(-)
> 
> diff --git a/tests/btrfs/057 b/tests/btrfs/057
> index b019f4e1e054..0b5a36d34852 100755
> --- a/tests/btrfs/057
> +++ b/tests/btrfs/057
> @@ -33,12 +33,9 @@ _require_scratch
>  rm -f $seqres.full
>  
>  # use small leaf size to get higher btree height.
> -run_check _scratch_mkfs "-b 1g --nodesize 4096"
> +run_check _scratch_mkfs "-b 1g"

There was feedback from Filipe on V1 that you also need to delete the
above comment since it's no longer valid.

>  
> -# inode cache is saved in the FS tree itself for every
> -# individual FS tree,that affects the sizes reported by qgroup show
> -# so we need to explicitly turn it off to get consistent values.
> -_scratch_mount "-o noinode_cache"
> +_scratch_mount
>  
>  # -w ensures that the only ops are ones which cause write I/O
>  run_check $FSSTRESS_PROG -d $SCRATCH_MNT -w -p 5 -n 1000 \
> @@ -53,14 +50,8 @@ run_check $FSSTRESS_PROG -d $SCRATCH_MNT/snap1 -w -p 5 -n 1000 \
>  _run_btrfs_util_prog quota enable $SCRATCH_MNT
>  _run_btrfs_util_prog quota rescan -w $SCRATCH_MNT
>  
> -# remove all file/dir other than subvolume
> -rm -rf $SCRATCH_MNT/snap1/* >& /dev/null
> -rm -rf $SCRATCH_MNT/p* >& /dev/null
> -
> -_run_btrfs_util_prog filesystem sync $SCRATCH_MNT
> -units=`_btrfs_qgroup_units`
> -$BTRFS_UTIL_PROG qgroup show $units $SCRATCH_MNT | $SED_PROG -n '/[0-9]/p' \
> -	| $AWK_PROG '{print $2" "$3}'
> +echo "Silence is golden"
> +# btrfs check will detect any qgroup number mismatch.
>  
>  status=0
>  exit
> diff --git a/tests/btrfs/057.out b/tests/btrfs/057.out
> index 60cb92d0926c..185023c79961 100644
> --- a/tests/btrfs/057.out
> +++ b/tests/btrfs/057.out
> @@ -1,3 +1,2 @@
>  QA output created by 057
> -4096 4096
> -4096 4096
> +Silence is golden
>