From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Wed, 24 Jun 2026 12:07:27 +0000 (+0300)
Subject: Avoid leaving DataChecksumState->worker_pid to an old value
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c008b7ea10a5037bf9c6573283b97f4ba56d65c0;p=thirdparty%2Fpostgresql.git

Avoid leaving DataChecksumState->worker_pid to an old value

It might be left to an old value if the launcher was terminated while
a worker was running.  launcher_exit() sends SIGTERM to the worker,
but did not clear 'worker_pid'.  Clear it, to be tidy.

Also clear it in ProcessDatabase() before starting a new datachecksums
worker, to be sure we start from a clean slate.  The codepath where
WaitForBackgroundWorkerStartup() returns BGWH_STOPPED but
worker_result != DATACHECKSUMSWORKER_SUCCESSFUL didn't clear it, while
all other codepaths did clear or set it.

Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://www.postgresql.org/message-id/b283fbb9-298e-4953-9120-eefaf24fae20@iki.fi
---

diff --git a/src/backend/postmaster/datachecksum_state.c b/src/backend/postmaster/datachecksum_state.c
index 9103546c382..79bd5cd26b5 100644
--- a/src/backend/postmaster/datachecksum_state.c
+++ b/src/backend/postmaster/datachecksum_state.c
@@ -817,6 +817,7 @@ ProcessDatabase(DataChecksumsWorkerDatabase *db)
 
 	LWLockAcquire(DataChecksumsWorkerLock, LW_EXCLUSIVE);
 	DataChecksumState->success = DATACHECKSUMSWORKER_FAILED;
+	DataChecksumState->worker_pid = InvalidPid;
 	LWLockRelease(DataChecksumsWorkerLock);
 
 	memset(&bgw, 0, sizeof(bgw));
@@ -856,9 +857,6 @@ ProcessDatabase(DataChecksumsWorkerDatabase *db)
 		{
 			LWLockRelease(DataChecksumsWorkerLock);
 			pgstat_report_activity(STATE_IDLE, NULL);
-			LWLockAcquire(DataChecksumsWorkerLock, LW_EXCLUSIVE);
-			DataChecksumState->worker_pid = InvalidPid;
-			LWLockRelease(DataChecksumsWorkerLock);
 			return DataChecksumState->success;
 		}
 		LWLockRelease(DataChecksumsWorkerLock);
@@ -951,6 +949,7 @@ launcher_exit(int code, Datum arg)
 			ereport(LOG,
 					errmsg("data checksums launcher exiting while worker is still running, signalling worker"));
 			kill(DataChecksumState->worker_pid, SIGTERM);
+			DataChecksumState->worker_pid = InvalidPid;
 		}
 		LWLockRelease(DataChecksumsWorkerLock);
 	}