From: Andres Freund <andres@anarazel.de>
To: pgsql-committers@lists.postgresql.org
Subject: pgsql: aio: Fix possible state confusions due to interrupt processing
Date: Tue, 20 May 2025 01:08:41 +0000
Message-ID: <E1uHBTE-002TFu-3D@gemulon.postgresql.org> (raw)
aio: Fix possible state confusions due to interrupt processing
elog()/ereport() process interrupts, iff the log message is < ERROR and the
log message will be emitted. aio's debug messages are emitted via ereport(),
but in some places the code is not ready for interrupts to be processed.
Fix the issue using a few different methods:
1) handle interrupts arriving concurrently - in some places it's easy to
detect that by fetching the handle's generation a bit earlier
2) Check if interrupts made the work needing to be done obsolete
3) Disallow interrupts, as there's no sane way to make interrupt processing
safe
To prevent some similar issues from being re-introduced, assert that
interrupts are held in pgaio_io_update_state().
This commit also fixes the contents of a debug message I added in 039bfc457e4.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/mvpm7ga3dfgz7bvum22hmuz26cariylmcppb3irayftc7bwk3r@l7gb6gr7azhc
Branch
------
master
Details
-------
https://git.postgresql.org/pg/commitdiff/acad909321a4742a78b83cf7e975e627e786af5c
Modified Files
--------------
src/backend/storage/aio/aio.c | 113 ++++++++++++++++++++++++++++++++++++------
1 file changed, 99 insertions(+), 14 deletions(-)
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-committers@postgresql.org
Cc: andres@anarazel.de, pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: aio: Fix possible state confusions due to interrupt processing
In-Reply-To: <E1uHBTE-002TFu-3D@gemulon.postgresql.org>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox