[CRIU] [PATCH] tty: Don't flush tty data on checkpoint stage

[Cyrill Gorcunov]

On Thu, Nov 22, 2012 at 01:24:38PM +0400, Andrey Wagin wrote:
> 2012/11/22 Cyrill Gorcunov <gorcunov at openvz.org>:
> > In case if we're dumping the peer which another
> > end belongs not to us but some other application
> > the attempts to flush data may lead to endless
> > SIGTTOU storm:
> 
> We have endless SIGTTOU storm, if crtools dump is traced by strace.
> If crtools dump is executed w/o strace, the dumping application is crashed.
> 
> I'm not sure, that we should not call ioctl(lfd, TCFLSH, TCIOFLUSH)
> for all terminals. I think it should not be called for external
> terminals.

The proper solution is to somehow fetch the data from the terminal
kernel's buffers and restore it back after. At moment we have no such
way in kernel. That said I think it doesn't make much sense to make a
flush at all.

	Cyrill