Date: Wed, 3 Aug 2022 11:02:00 -0500
From: Justin Pryzby <pryzby@telsasoft.com>
To: Dilip Kumar <dilipbalaut@gmail.com>
Cc: Andres Freund <andres@anarazel.de>, Tom Lane <tgl@sss.pgh.pa.us>,
	Robert Haas <robertmhaas@gmail.com>,
	Ashutosh Sharma <ashu.coek88@gmail.com>,
	Maciek Sakrejda <m.sakrejda@gmail.com>,
	Bruce Momjian <bruce@momjian.us>,
	Alvaro Herrera <alvherre@alvh.no-ip.org>,
	Andrew Dunstan <andrew@dunslane.net>,
	Heikki Linnakangas <hlinnaka@iki.fi>,
	pgsql-hackers@lists.postgresql.org
Subject: Re: [Proposal] Fully WAL logged CREATE DATABASE - No Checkpoints
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On Wed, Aug 03, 2022 at 04:45:23PM +0530, Dilip Kumar wrote:
> Another version of the patch which closes the smgr at the end using
> smgrcloserellocator() and I have also added a commit message.

Thanks for providing a patch.
This seems to fix the second problem with accessing freed memory.

But I reproduced the first problem with a handful of tries interrupting the
while loop:

2022-08-03 10:39:50.129 CDT client backend[5530] [unknown] PANIC:  could no=
t open critical system index 2662

In the failure, when trying to connect to the new "a" DB, it does this:

[pid 10700] openat(AT_FDCWD, "base/17003/pg_filenode.map", O_RDONLY) =3D 11
[pid 10700] read(11, "\27'Y\0\21\0\0\0\353\4\0\0\353\4\0\0\341\4\0\0\341\4\=
0\0\347\4\0\0\347\4\0\0\337\4\0\0\337\4\0\0\24\v\0\0\24\v\0\0\25\v\0\0\25\v=
\0\0K\20\0\0K\20\0\0L\20\0\0L\20\0\0\202\n\0\0\202\n\0\0\203\n\0\0\203\n\0\=
0\217\n\0\0\217\n\0\0\220\n\0\0\220\n\0\0b\n\0\0b\n\0\0c\n\0\0c\n\0\0f\n\0\=
0f\n\0\0g\n\0\0g\n\0\0\177\r\0\0\177\r\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\=
0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0=
\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\=
0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0=
\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\=
0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0=
\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\=
0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0=
\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\=
0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0=
\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\362\366\252\337", 524) =3D 524
[pid 10700] close(11)                   =3D 0
[pid 10700] openat(AT_FDCWD, "base/17003/pg_internal.init", O_RDONLY) =3D -=
1 ENOENT (No such file or directory)
[pid 10700] openat(AT_FDCWD, "base/17003/1259", O_RDWR) =3D 11
[pid 10700] lseek(11, 0, SEEK_END)      =3D 106496
[pid 10700] lseek(11, 0, SEEK_END)      =3D 106496

And then reads nothing but zero bytes from FD 11 (rel 1259/pg_class)

So far, I haven't succeeded in eliciting anything useful from valgrind.

--=20
Justin