Re: Add pg_file_sync() to adminpack

Julien Rouhaud <rjuju123@gmail.com>

From: Julien Rouhaud <rjuju123@gmail.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: Fujii Masao <masao.fujii@gmail.com>, Arthur Zakirov <zaartur@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2020-01-14T06:26:07Z
Lists: pgsql-hackers
On Tue, Jan 14, 2020 at 7:18 AM Michael Paquier <michael@paquier.xyz> wrote:
>
> On Mon, Jan 13, 2020 at 03:39:32PM +0100, Julien Rouhaud wrote:
> > Actually, can't it create a security hazard, for instance if you call
> > pg_file_sync() on a heap file and the calls errors out, since it's
> > bypassing data_sync_retry?
>
> Are you mistaking security with durability here?

Yes, data durability sorry.

>  By default, the
> function proposed is only executable by a superuser, so that's not
> really a security concern..  But I agree that failing to detect a
> PANIC on a fsync for a sensitive Postgres file could lead to
> corruptions.  That's why we PANIC these days.

Exactly.  My concern is that some superuser may not be aware that
pg_file_sync could actually corrupt data, so there should be a big red
warning explaining that.



Commits

  1. Add pg_file_sync() to adminpack extension.