Horton

Re: Incorrect logic in XLogNeedsFlush()

Jeff Davis <pgsql@j-davis.com>

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From: Jeff Davis <pgsql@j-davis.com>
To: Dilip Kumar <dilipbalaut@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>, Melanie Plageman <melanieplageman@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Andres Freund <andres@anarazel.de>
Date: 2025-09-14T17:53:07Z
Lists: pgsql-hackers 
On Sun, 2025-09-14 at 13:39 +0530, Dilip Kumar wrote:
> I tried to improve it in v2

Thank you. Looks good to me.

> 
> IMHO during crash recovery LocalMinRecoveryPoint and
> ControlFile->minRecoveryPoint can not initialized until we replay all
> WAL so those should never get accessed.  However if XLogNeedsFlush()
> were called during the end of the recovery checkpoint it was
> accessing
> this which was wrong although it was not a live bug and this patch is
> making that more resilient.

OK, so this will no longer be a concern after the patch (and not a live
bug before, anyway).

Regards,
	Jeff Davis

Commits

  1. Reorder XLogNeedsFlush() checks to be more consistent

  2. Make XLogFlush() and XLogNeedsFlush() decision-making more consistent