[CRIU] [PATCH 1/2] tty: Write unread pty buffers on post dump stage

[Cyrill Gorcunov]

On Fri, May 13, 2016 at 05:28:00PM +0300, Pavel Emelyanov wrote:
> >>
> >> Any reason why data is put into global list and is then picked by
> >> ttys instead of tty itself is searched at data collect stage and
> >> receives data in its list_head?
> > 
> > Not sure I follow this moment. Queued data are saved in records inside
> > separate image, and it's collected automatically, into one list.
> 
> Yup. My point is that -- why not collect this data into respective tty's
> list immediately? We already have list of all tty to lookup tty from,
> so we'd avoid introducing yet another one.

We need to keep the data read somewhere. Look, I guess it's unclean from
the patch itself. Here is how we collect everything:

static struct collect_image_info *cinfos[] = {
	...
	&tty_cdata,
	&tty_info_cinfo,
	&tty_cinfo,
	...
};

The &tty_cdata represents records in tty-data.img, which has only
id per each record, so each record is hooked into one global list
which we use for lookup later.

static int collect_one_tty(void *obj, ProtobufCMessage *msg, struct cr_img *i)
{
	info->tie = lookup_tty_info_entry(info->tfe->tty_info_id);
	info->tty_data = is_pty(info->driver) ? tty_lookup_data(info) : NULL;

here we walk over records from @&tty_cdata and find which queue
blongs to particular tty entry we're reading from image now.

Could you please write in pseudocode which exactly you would like to see here?