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

[Serge Hallyn]

Quoting Stéphane Graber (stgraber at ubuntu.com):
> 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).

Ok, good point - I'll remove that and push thanks.

> 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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