[pve-devel] [PATCH container] Fix pct skiplock

[Thomas Lamprecht]

On 03/13/2018 05:20 PM, Alwin Antreich wrote:
> The method vm_start sets an environment variable that is not picked up
> anymore by systemd. This patch keeps the environment variable and
> introduces a skiplock file that is picked up by the
> lxc-pve-prestart-hook.
> 
> Signed-off-by: Alwin Antreich <a.antreich at proxmox.com>
> ---
>  src/PVE/LXC.pm            | 9 ++++++++-
>  src/lxc-pve-prestart-hook | 5 ++++-
>  2 files changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/src/PVE/LXC.pm b/src/PVE/LXC.pm
> index 7adbcd1..2e3e4ca 100644
> --- a/src/PVE/LXC.pm
> +++ b/src/PVE/LXC.pm
> @@ -1545,7 +1545,14 @@ sub vm_start {
>  
>      update_lxc_config($vmid, $conf);
>  
> -    local $ENV{PVE_SKIPLOCK}=1 if $skiplock;
> +    if ($skiplock) {
> +	# to stay compatible with old behaviour
> +	local $ENV{PVE_SKIPLOCK}=1;

if it never gets passed along at all, no point in trying
to stay compatible, or?

> +
> +	my $file = "/var/lib/lxc/$vmid/skiplock";

use /run/lxc/... or /run/pve-container (the former exists already)
those are guaranteed to be tmpfs and thus a reboot clears possible
left over flag files

> +	open(my $fh, '>', $file) || die "failed to open $file for writing: $!\n";
> +	close($fh);
> +    }
>  
>      my $cmd = ['systemctl', 'start', "pve-container\@$vmid"];
>  
> diff --git a/src/lxc-pve-prestart-hook b/src/lxc-pve-prestart-hook
> index fd29423..abe61aa 100755
> --- a/src/lxc-pve-prestart-hook
> +++ b/src/lxc-pve-prestart-hook
> @@ -57,13 +57,16 @@ __PACKAGE__->register_method ({
>  	return undef if $param->{name} !~ m/^\d+$/;
>  
>  	my $vmid = $param->{name};
> +	my $file = "/var/lib/lxc/$vmid/skiplock";

$file is very ambiguous, maybe $skiplock_flag_fn?

> +	my $skiplock = $ENV{PVE_SKIPLOCK} || 1 if -e $file;

don't do that, it's quite confusing, for what is the if?
the whole assign, then you could omit the $ENV{PVE_SKIPLOCK}
part...

Do either

my $skiplock = $ENV{PVE_SKIPLOCK} || -e $file;

or maybe even better:
my $skiplock = $ENV{PVE_SKIPLOCK}; # backwar copatibillity
$skiplock = 1 if -e $file;

Or if you say systemd does not picks this up just omit the $ENV
completely?


> +	unlink $file if -e $file;
>  
>  	PVE::Cluster::check_cfs_quorum(); # only start if we have quorum
>  
>  	return undef if ! -f PVE::LXC::Config->config_file($vmid);
>  
>  	my $conf = PVE::LXC::Config->load_config($vmid);
> -	if (!$ENV{PVE_SKIPLOCK} && !PVE::LXC::Config->has_lock($conf, 'mounted')) {
> +	if (!$skiplock && !PVE::LXC::Config->has_lock($conf, 'mounted')) {
>  	    PVE::LXC::Config->check_lock($conf);
>  	}
>  
>