[lxc-devel] [PATCH 1/1] stop: add nolock option

[Stéphane Graber]

On Mon, Dec 16, 2013 at 08:04:18AM -0600, Serge Hallyn wrote:
> If the system gets into a bad state, it may become impossible to get
> the lxc container locks.  We should still be able to stop containers
> in that case.  Add a -L/--nolock option to specify this behavior.
> 
> Signed-off-by: Serge Hallyn <serge.hallyn at ubuntu.com>


Since this likely won't be used terribly often, I'd prefer if we didn't
allocate it a shortcut (-L) but instead only supported the full name
(--nolock).

The code looks good though.

Acked-by: Stéphane Graber <stgraber at ubuntu.com>

> ---
>  doc/lxc-stop.sgml.in | 14 ++++++++++++++
>  src/lxc/arguments.h  |  3 +++
>  src/lxc/lxc_stop.c   |  8 ++++++++
>  3 files changed, 25 insertions(+)
> 
> diff --git a/doc/lxc-stop.sgml.in b/doc/lxc-stop.sgml.in
> index d5f8510..d817a99 100644
> --- a/doc/lxc-stop.sgml.in
> +++ b/doc/lxc-stop.sgml.in
> @@ -54,6 +54,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
>        <arg choice="opt">-r</arg>
>        <arg choice="opt">-t <replaceable>timeout</replaceable></arg>
>        <arg choice="opt">-k</arg>
> +      <arg choice="opt">-L</arg>
>        <arg choice="opt">-s</arg>
>      </cmdsynopsis>
>    </refsynopsisdiv>
> @@ -122,6 +123,19 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
>  
>      <varlistentry>
>  	<term>
> +	  <option>-L,--nolock </option>
> +	</term>
> +	<listitem>
> +	  <para>
> +	This option avoids the use of any of the API lxc locking, and should
> +	only be used if <command>lxc-stop</command> is hanging due to a bad
> +	system state.
> +	  </para>
> +	</listitem>
> +	</varlistentry>
> +
> +    <varlistentry>
> +	<term>
>  	  <option>-W,--nowait </option>
>  	</term>
>  	<listitem>
> diff --git a/src/lxc/arguments.h b/src/lxc/arguments.h
> index 021f552..f574fc4 100644
> --- a/src/lxc/arguments.h
> +++ b/src/lxc/arguments.h
> @@ -73,6 +73,9 @@ struct lxc_arguments {
>  	int hardstop;
>  	int shutdown;
>  
> +	/* for lxc-stop */
> +	int nolock;
> +
>  	/* for lxc-destroy */
>  	int force;
>  
> diff --git a/src/lxc/lxc_stop.c b/src/lxc/lxc_stop.c
> index 7203d75..fc541a0 100644
> --- a/src/lxc/lxc_stop.c
> +++ b/src/lxc/lxc_stop.c
> @@ -41,6 +41,7 @@ static int my_parser(struct lxc_arguments* args, int c, char* arg)
>  	case 't': args->timeout = atoi(arg); break;
>  	case 'k': args->hardstop = 1; break;
>  	case 's': args->shutdown = 1; break;
> +	case 'L': args->nolock = 1; break;
>  	}
>  	return 0;
>  }
> @@ -51,6 +52,7 @@ static const struct option my_longopts[] = {
>  	{"timeout", required_argument, 0, 't'},
>  	{"kill", no_argument, 0, 'k'},
>  	{"shutdown", no_argument, 0, 's'},
> +	{"no-lock", no_argument, 0, 'L'},
>  	LXC_COMMON_OPTIONS
>  };
>  
> @@ -67,6 +69,7 @@ Options :\n\
>    -W, --nowait      don't wait for shutdown or reboot to complete\n\
>    -t, --timeout=T   wait T seconds before hard-stopping\n\
>    -k, --kill        kill container rather than request clean shutdown\n\
> +  -L, --nolock      Avoid using API locks\n\
>    -s, --shutdown    Only request clean shutdown, don't later force kill\n",
>  	.options  = my_longopts,
>  	.parser   = my_parser,
> @@ -139,6 +142,11 @@ int main(int argc, char *argv[])
>  			 my_args.progname, my_args.quiet, my_args.lxcpath[0]))
>  		return 1;
>  
> +	/* shortcut - if locking is bogus, we should be able to kill
> +	 * containers at least */
> +	if (my_args.nolock)
> +		return lxc_cmd_stop(my_args.name, my_args.lxcpath[0]);
> +
>  	c = lxc_container_new(my_args.name, my_args.lxcpath[0]);
>  	if (!c) {
>  		fprintf(stderr, "Error opening container\n");
> -- 
> 1.8.5.1
> 
> _______________________________________________
> lxc-devel mailing list
> lxc-devel at lists.linuxcontainers.org
> http://lists.linuxcontainers.org/listinfo/lxc-devel

-- 
Stéphane Graber
Ubuntu developer
http://www.ubuntu.com
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