Re: lazy_scan_heap() forgets to mark buffer dirty when setting allfrozen?

Hi,

On 2019-04-08 00:48:20 -0400, Alvaro Herrera wrote:
> On 2019-Apr-07, Andres Freund wrote:
> 
> > lazy_scan_heap() contains the following block:
> > 
> >         /*
> >          * If the all-visible page is turned out to be all-frozen but not
> >          * marked, we should so mark it.  Note that all_frozen is only valid
> >          * if all_visible is true, so we must check both.
> >          */
> >         else if (all_visible_according_to_vm && all_visible && all_frozen &&
> >                  !VM_ALL_FROZEN(onerel, blkno, &vmbuffer))
> >         {
> >             /*
> >              * We can pass InvalidTransactionId as the cutoff XID here,
> >              * because setting the all-frozen bit doesn't cause recovery
> >              * conflicts.
> >              */
> >             visibilitymap_set(onerel, blkno, buf, InvalidXLogRecPtr,
> >                               vmbuffer, InvalidTransactionId,
> >                               VISIBILITYMAP_ALL_FROZEN);
> >         }
> > 
> > but I'm afraid that's not quite enough.
> 
> Apparently the initial commit a892234f830e had MarkBufferDirty, but it
> was removed one week later by 77a1d1e79892.

Good catch. Kinda looks like it could have been an accidental removal?
Robert?

Greetings,

Andres Freund