Subject: Re: pg11+: pg_ls_*dir LIMIT 1: temporary files .. not closed at
 end-of-transaction
To: Tom Lane <tgl@sss.pgh.pa.us>, Justin Pryzby <pryzby@telsasoft.com>
Cc: Fabien COELHO <coelho@cri.ensmp.fr>, pgsql-hackers@postgresql.org,
 Alvaro Herrera <alvherre@2ndquadrant.com>, David Steele
 <david@pgmasters.net>, "Bossart, Nathan" <bossartn@amazon.com>,
 Thomas Munro <thomas.munro@gmail.com>
References: <24244.1585415634@sss.pgh.pa.us>
 <20200328183904.GI20103@telsasoft.com> <28906.1585422475@sss.pgh.pa.us>
 <27064.1585499825@sss.pgh.pa.us> <20200329171415.GL20103@telsasoft.com>
 <29512.1585502524@sss.pgh.pa.us> <20200329201215.GM20103@telsasoft.com>
 <alpine.DEB.2.21.2003300704430.16227@pseudo> <4028.1585579463@sss.pgh.pa.us>
 <alpine.DEB.2.21.2003310723560.16227@pseudo>
 <20200331080643.GE14618@telsasoft.com> <11882.1585672910@sss.pgh.pa.us>
From: Alexander Lakhin <exclusion@gmail.com>
Message-ID: <83048c77-2531-48cb-aa2b-aa01cc5af519@gmail.com>
Date: Fri, 13 Nov 2020 23:00:00 +0300
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Hello hackers,
31.03.2020 19:41, Tom Lane wrote:
> Justin Pryzby <pryzby@telsasoft.com> writes:
>> I suggest to leave stat() alone in your patch for stable releases.  I think
>> it's okay if we change behavior so that a broken symlink is skipped instead of
>> erroring (as a side effect of skipping ENOENT with stat()).  But not okay if we
>> change pg_ls_logdir() to hide symlinks in back braches.
> Meh.  I'm not really convinced, but in the absence of anyone expressing
> support for my position, I'll do it that way.  I don't think it's worth
> doing both a stat and lstat to tell the difference between file-is-gone
> and file-is-a-broken-symlink.
As we've discovered in Bug #[16161], stat() for "concurrently-deleted
file" can also return ERROR_ACCESS_DENIED on Windows. It seems that
pg_upgradeCheck failures seen on
https://buildfarm.postgresql.org/cgi-bin/show_history.pl?nm=fairywren&br=REL_13_STABLE
caused by the same issue.
Shouldn't pg_ls_dir_files() retry stat() on ERROR_ACCESS_DENIED just
like the pgwin32_open() does to ignore files in "delete pending" state?

[16161]
https://www.postgresql.org/message-id/16161-7a985d2f1bbe8f71%40postgresql.org

Best regards,
Alexander