Re: [PATCH] generic/520: use fsync instead of sync during clean_dir

From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
Cc: fstests@vger.kernel.org
Subject: Re: [PATCH] generic/520: use fsync instead of sync during clean_dir
Date: Fri, 13 Dec 2019 12:42:41 -0800	[thread overview]
Message-ID: <20191213204241.GC99869@magnolia> (raw)
In-Reply-To: <1576215941-19208-1-git-send-email-xuyang2018.jy@cn.fujitsu.com>

On Fri, Dec 13, 2019 at 01:45:41PM +0800, Yang Xu wrote:
> When I test this case on xfs, it may fail as below:
> --------------------------------------------
>  === link SCRATCH_MNT/A/foo SCRATCH_MNT/bar  with fsync SCRATCH_MNT/A ===
> +umount: /mnt/xfstests/scratch: target is busy.
> +        (In some cases useful info about processes that use
> +         the device is found by lsof(8) or fuser(1))
> ---------------------------------------------
> 
> I think we don't need to sync all fs and fsync SCRATCH_MNT is enough.
> 
> Signed-off-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
> ---
>  tests/generic/520 | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tests/generic/520 b/tests/generic/520
> index 167d7077..a16467ca 100755
> --- a/tests/generic/520
> +++ b/tests/generic/520
> @@ -58,7 +58,7 @@ clean_dir()
>  {
>  	_mount_flakey
>  	rm -rf $(find $SCRATCH_MNT/* | grep -v "lost+found")
> -	sync
> +	$XFS_IO_PROG -c "fsync" $SCRATCH_MNT

But that only has to force the scratch mount directory to disk.

Assuming the test authors really meant "write all of the scratch fs'
dirty data/metadata to disk", I think you want:

 $XFS_IO_PROG -c syncfs $SCRATCH_MNT

here?

Also, why did umount spit out 'target is busy' here?  clean_dir() erases
the scratch fs between tests, there shouldn't be anything flakey about
that.

--D

>  	_unmount_flakey
>  }
>  
> -- 
> 2.18.0
> 
> 
> 