Hello hackers,
I think we should be ensuring that directory entries for newly created
multixact files are durable at checkpoint time. Please see attached.
From 89e5b787ea5efd03ced8da46f95f236e03bf4adf Mon Sep 17 00:00:00 2001
From: Thomas Munro <[email protected]>
Date: Wed, 23 Sep 2020 13:02:27 +1200
Subject: [PATCH 1/2] Fix missing fsync of multixact directories.
Standardize behavior by moving reponsibility for fsyncing directories
down into slru.c.
Back-patch to all supported releases.
---
src/backend/access/transam/clog.c | 7 -------
src/backend/access/transam/commit_ts.c | 6 ------
src/backend/access/transam/slru.c | 7 +++++++
3 files changed, 7 insertions(+), 13 deletions(-)
diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c
index 65aa8841f7..9e352d2658 100644
--- a/src/backend/access/transam/clog.c
+++ b/src/backend/access/transam/clog.c
@@ -836,13 +836,6 @@ CheckPointCLOG(void)
/* Flush dirty CLOG pages to disk */
TRACE_POSTGRESQL_CLOG_CHECKPOINT_START(true);
SimpleLruFlush(XactCtl, true);
-
- /*
- * fsync pg_xact to ensure that any files flushed previously are durably
- * on disk.
- */
- fsync_fname("pg_xact", true);
-
TRACE_POSTGRESQL_CLOG_CHECKPOINT_DONE(true);
}
diff --git a/src/backend/access/transam/commit_ts.c b/src/backend/access/transam/commit_ts.c
index 5244b06a2b..f6a7329ba3 100644
--- a/src/backend/access/transam/commit_ts.c
+++ b/src/backend/access/transam/commit_ts.c
@@ -822,12 +822,6 @@ CheckPointCommitTs(void)
{
/* Flush dirty CommitTs pages to disk */
SimpleLruFlush(CommitTsCtl, true);
-
- /*
- * fsync pg_commit_ts to ensure that any files flushed previously are
- * durably on disk.
- */
- fsync_fname("pg_commit_ts", true);
}
/*
diff --git a/src/backend/access/transam/slru.c b/src/backend/access/transam/slru.c
index 7640f153c2..89ce7c43b5 100644
--- a/src/backend/access/transam/slru.c
+++ b/src/backend/access/transam/slru.c
@@ -1187,6 +1187,13 @@ SimpleLruFlush(SlruCtl ctl, bool allow_redirtied)
}
if (!ok)
SlruReportIOError(ctl, pageno, InvalidTransactionId);
+
+ /*
+ * Make sure that the directory entries for any newly created files are on
+ * disk.
+ */
+ if (ctl->do_fsync)
+ fsync_fname(ctl->Dir, true);
}
/*
--
2.20.1
