linux-kernel - Re: [PATCH] ktest: Add workaround to avoid unexpected power cycle

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Date:   Wed, 17 Apr 2019 16:29:42 -0400
From:   Steven Rostedt <rostedt@...dmis.org>
To:     Masayoshi Mizuma <msys.mizuma@...il.com>
Cc:     Masayoshi Mizuma <m.mizuma@...fujitsu.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] ktest: Add workaround to avoid unexpected power cycle

On Wed, 17 Apr 2019 16:14:42 -0400
Masayoshi Mizuma <msys.mizuma@...il.com> wrote:

> From: Masayoshi Mizuma <m.mizuma@...fujitsu.com>
> 
> Unexpected power cycle occurs while the installation of the
> kernel.
> 
> That is because the default reboot command, "ssh $SSH_USER@...CHINE
> reboot" exits as 255 even if the reboot is successfully done,
> like as:
> 
>   ]# ssh root@...t reboot
>   Connection to Test closed by remote host.
>   ]# echo $?
>   255
>   ]#
> 
> To avoid the unexpected power cycle, the reboot is considered as
> successfully done if the reboot is the default command and the
> return code is 255.
> 

Ah that explains why I've been seeing this :-)

Can we add a config modifying variable called:

REBOOT_RETURN_CODE

that is by default 255 and can be changed by the config file?

You just need to add in %default:

	"REBOOT_RETURN_CODE"	=> 255,

my $reboot_return_code;


and in %option_map:

	"REBOOT_RETURN_CODE"	=> \$reboot_return_code,


> Signed-off-by: Masayoshi Mizuma <m.mizuma@...fujitsu.com>
> ---
>  tools/testing/ktest/ktest.pl | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/tools/testing/ktest/ktest.pl b/tools/testing/ktest/ktest.pl
> index ea07d43856b8..765c6bc83ab4 100755
> --- a/tools/testing/ktest/ktest.pl
> +++ b/tools/testing/ktest/ktest.pl
> @@ -1737,6 +1737,11 @@ sub run_command {
>      my $dord = 0;
>      my $dostdout = 0;
>      my $pid;
> +    my $is_default_reboot = 0;
> +
> +    if ($command eq $default{REBOOT}) {
> +	$is_default_reboot = 1;
> +    }

Do we really need to add this variable?

>  
>      $command =~ s/\$SSH_USER/$ssh_user/g;
>      $command =~ s/\$MACHINE/$machine/g;
> @@ -1791,6 +1796,10 @@ sub run_command {
>      # shift 8 for real exit status
>      $run_command_status = $? >> 8;
>  
> +    if ($run_command_status == 255 && $is_default_reboot) {

Instead can we have:

	if ($command eq $default{REBOOT} &&
	    $run_command_status == $reboot_return_code) {

?

Thanks for these patches!

-- Steve

> +	$run_command_status = 0;
> +    }
> +
>      close(CMD);
>      close(LOG) if ($dolog);
>      close(RD)  if ($dord);