[Devel] [RFC rh7 v4] ve/tty: vt -- Implement per VE support for console and terminals

[Vladimir Davydov]

On Thu, Aug 27, 2015 at 04:11:38PM +0300, Cyrill Gorcunov wrote:
> On Thu, Aug 27, 2015 at 03:58:13PM +0300, Vladimir Davydov wrote:
> > On Mon, Aug 24, 2015 at 02:08:56PM +0300, Cyrill Gorcunov wrote:
> > > On Mon, Aug 24, 2015 at 01:34:18PM +0300, Vladimir Davydov wrote:
> > ...
> > > > If a process inside a container closes and then immediately reopens a
> > > > vtty, it does not expect to get -EIO simply because it is advancing too
> > > > fast.
> > > 
> > > How it that? I mean, application (getty and such) always care about eio
> > > and such things.
> > 
> > No. If tty_open() returns -EIO mingetty dies:
> > 
> > : /sbin/mingetty[845]: console: cannot open tty: Input/output error
> > 
> > It will be respawned in a moment though, but it is ugly.
> 
> It doesnt matter how some particular program (getty or whatever)
> reacts on tty open error. By "care" I mean to either plain exit
> and rely on service to be restarted, or a program may sleep sometime
> and try again. What I mean is that this is absolutely valid to
> obtain -eio here. Anyway this should be addressed in a new version
> of a patch. Please give it a glance once time permit.

OK, I see now. Open-vs-close race is perfectly normal by design and we
don't need to handle them. This simplifies things a lot. Thanks for
pointing this out.