Re: [PATCH] ext4/021: make sure the fdatasync subprocess exits

[Eryu Guan <guaneryu@gmail.com>]

On Fri, Feb 14, 2020 at 10:20:01AM +0800, zhangyi (F) wrote:
> Now we just kill fdatasync_work process and wait nothing after the
> test, so a busy unmount failure may appear if the fdatasync syscall
> doesn't return in time.
> 
>   umount: /tmp/scratch: target is busy.
>   mount: /tmp/scratch: /dev/sdb already mounted on /tmp/scratch.
>   !!! failed to remount /dev/sdb on /tmp/scratch
> 
> This patch kill and wait the xfs_io fdatasync subprocess to make sure
> _check_scratch_fs success.

Yeah, that's a problem.

I think you could add another "trap" in fdatasync_work, as what
btrfs/036 does:

	trap "wait; exit" SIGTERM

So xfs_io will be waited by fdatasync_work before exiting.

Thanks,
Eryu

> 
> Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
> ---
>  tests/ext4/021 | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/tests/ext4/021 b/tests/ext4/021
> index 519737e1..1b4a1ced 100755
> --- a/tests/ext4/021
> +++ b/tests/ext4/021
> @@ -18,6 +18,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
>  
>  _cleanup()
>  {
> +	$KILLALL_PROG -wq xfs_io
>  	cd /
>  	rm -f $tmp.*
>  }
> -- 
> 2.23.0.rc2.8.gff66981f45
>