Re: heap_xlog_lock forgets to reset HEAP_XMAX_INVALID

On 2016-07-15 17:23:57 -0400, Alvaro Herrera wrote:
> Andres Freund wrote:
>
> > While validating my patch for http://archives.postgresql.org/message-id/20160714060607.klwgq2qr7egt3zrr%40alap3.anarazel.de
> > I noticed that the standby's infomask still had HEAP_XMAX_INVALID set
> > after replaying a XLOG_HEAP_LOCK record.
> >
> > That's bad, but not really commonly fatal, because unless prepared
> > transactions are used, locks don't need to be present / valid after
> > crash-recovery. But it's clearly something we need to fix.
> >
> > Given that it's been this way for ages, it's not a blocker for
> > committing the fix for above URL, but I'll try to get in something today
> > for that as well.
>
> Yes, it looks broken, and the consequences for prepared xacts should be
> pretty obvious. Other than those, I think it's pretty innocuous.

Yea, I can't see anything else right now.

> > Looks like the minimal fix is just to add
> > htup->t_infomask &= ~(HEAP_XMAX_BITS | HEAP_MOVED);
> > htup->t_infomask2 &= ~HEAP_KEYS_UPDATED;
> > to heap_xlog_lock and heap_xlog_lock_updated.
>
> Maybe we should change fix_infomask_from_infobits() to reset
> HEAP_XMAX_BITS | HEAP_MOVED too (and HEAP_KEYS_UPDATED I suppose), to
> avoid doing it in each callsite.

Yea, I was thinking of that as well. But there's code like
htup->t_infomask &= ~(HEAP_XMAX_BITS | HEAP_MOVED);
htup->t_infomask2 &= ~HEAP_KEYS_UPDATED;
if (hot_update)
HeapTupleHeaderSetHotUpdated(htup);
else
HeapTupleHeaderClearHotUpdated(htup);
fix_infomask_from_infobits(xlrec->old_infobits_set, &htup->t_infomask,
&htup->t_infomask2);

so I'd rather only clean this up in master.

Andres