pgsql: Fix deadlock between ginDeletePage() and ginStepRight() - Mailing list pgsql-committers

From Alexander Korotkov
Subject pgsql: Fix deadlock between ginDeletePage() and ginStepRight()
Date
Msg-id E1iXAjx-0001cn-C1@gemulon.postgresql.org
Whole thread Raw
List pgsql-committers
Fix deadlock between ginDeletePage() and ginStepRight()

When ginDeletePage() is about to delete page it locks its left sibling to revise
the rightlink.  So, it locks pages in right to left manner.  Int he same time
ginStepRight() locks pages in left to right manner, and that could cause a
deadlock.

This commit makes ginScanToDelete() keep exclusive lock on left siblings of
currently investigated path.  That elimites need to relock left sibling in
ginDeletePage().  Thus, deadlock with ginStepRight() can't happen anymore.

Reported-by: Chen Huajun
Discussion: https://postgr.es/m/5c332bd1.87b6.16d7c17aa98.Coremail.chjischj%40163.com
Author: Alexander Korotkov
Reviewed-by: Peter Geoghegan
Backpatch-through: 10

Branch
------
REL_12_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/051c50c01c32ceb498d53e78f48297713744b7cb

Modified Files
--------------
src/backend/access/gin/README      | 79 ++++++++++++++++++++++----------------
src/backend/access/gin/ginvacuum.c | 54 +++++++++++++++++---------
2 files changed, 81 insertions(+), 52 deletions(-)


pgsql-committers by date:

Previous
From: Alexander Korotkov
Date:
Subject: pgsql: Fix deadlock between ginDeletePage() and ginStepRight()
Next
From: Alexander Korotkov
Date:
Subject: pgsql: Fix deadlock between ginDeletePage() and ginStepRight()