v2-0001-Fix-background-worker-not-restarting-after-crash-.patch
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Filename: v2-0001-Fix-background-worker-not-restarting-after-crash-.patch
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Format: format-patch
Series: patch v2-0001
Subject: Fix background worker not restarting after crash-and-restart cycle.
| File | + | − |
|---|---|---|
| src/backend/postmaster/bgworker.c | 1 | 0 |
| src/backend/postmaster/postmaster.c | 7 | 0 |
From f1faa31a43ac7365d7681c01fe39977469bfe107 Mon Sep 17 00:00:00 2001
From: Fujii Masao <fujii@postgresql.org>
Date: Fri, 25 Jul 2025 09:50:35 +0900
Subject: [PATCH v2] Fix background worker not restarting after
crash-and-restart cycle.
Previously, if a background worker crashed (e.g., due to a SIGKILL) and
the server restarted due to restart_after_crash being enabled,
the worker was not restarted as expected. Background workers without
the never-restart flag should automatically restart in this case.
This issue was introduced in commit 28a520c0b77, which failed to reset
the rw_pid field in the RegisteredBgWorker struct for the crashed worker.
This commit fixes the problem by resetting rw_pid for all eligible
background workers during the crash-and-restart cycle.
Back-patched to v18, where the bug was introduced.
Bug fix patches were proposed by Andrey Rudometov and ChangAo Chen,
but this commit uses a different approach.
Reported-by: Andrey Rudometov <unlimitedhikari@gmail.com>
Reported-by: ChangAo Chen <cca5507@qq.com>
Author: Andrey Rudometov <unlimitedhikari@gmail.com>
Author: ChangAo Chen <cca5507@qq.com>
Co-authored-by: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Shveta Malik <shveta.malik@gmail.com>
Discussion: https://postgr.es/m/CAF6JsWiO=i24qYitWe6ns1sXqcL86rYxdyU+pNYk-WueKPSySg@mail.gmail.com
Discussion: https://postgr.es/m/tencent_E00A056B3953EE6440F0F40F80EC30427D09@qq.com
Backpatch-through: 18
---
src/backend/postmaster/bgworker.c | 1 +
src/backend/postmaster/postmaster.c | 7 +++++++
2 files changed, 8 insertions(+)
diff --git a/src/backend/postmaster/bgworker.c b/src/backend/postmaster/bgworker.c
index 116ddf7b835..1ad65c237c3 100644
--- a/src/backend/postmaster/bgworker.c
+++ b/src/backend/postmaster/bgworker.c
@@ -613,6 +613,7 @@ ResetBackgroundWorkerCrashTimes(void)
* resetting.
*/
rw->rw_crashed_at = 0;
+ rw->rw_pid = 0;
/*
* If there was anyone waiting for it, they're history.
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index cca9b946e53..e01d9f0cfe8 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -2630,6 +2630,13 @@ CleanupBackend(PMChild *bp,
}
bp = NULL;
+ /*
+ * In a crash case, exit immediately without resetting background worker
+ * state. However, if restart_after_crash is enabled, the background
+ * worker state (e.g., rw_pid) still needs be reset so the worker can
+ * restart after crash recovery. This reset is handled in
+ * ResetBackgroundWorkerCrashTimes(), not here.
+ */
if (crashed)
{
HandleChildCrash(bp_pid, exitstatus, procname);
--
2.50.1