postgres.git / summary / log / commit / refs

commit    d771b0a907e67dc929dbbdebf70ecb006081b629
Author:   Daniel Gustafsson <dgustafsson@postgresql.org>
Date:     Sun Apr 05 23:55:06 2026 +0000

    Handle checksumworker startup wait race
    
    If the background worker for processing databases manages to finish
    before the launcher starts waiting for it, the launcher would treat
    it erroneously as an error.  Fix by ensureing to check result state
    in this case.  Identified on CI and synthetically reproduced during
    local testing.
    
    Also while, make sure to properly lock the shared memory structure
    before updating tje result state.
    
    Author: Daniel Gustafsson <daniel@yesql.seA
    Reported-by: Andres Freund <andres@anarazel.de>
    Discussion: https://postgr.es/m/4fxw37ge47v5baeozla5phymi233hxbcjbwwsfwv3mpg3kyl2z@6jk4nkf6jp4


 src/backend/postmaster/datachecksum_state.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/backend/postmaster/datachecksum_state.c b/src/backend/postmaster/datachecksum_state.c
index eb7b01d0993..430e6e9a3c9 100644
--- a/src/backend/postmaster/datachecksum_state.c
+++ b/src/backend/postmaster/datachecksum_state.c
@@ -797,6 +797,19 @@ ProcessDatabase(DataChecksumsWorkerDatabase *db)
 	status = WaitForBackgroundWorkerStartup(bgw_handle, &pid);
 	if (status == BGWH_STOPPED)
 	{
+		/*
+		 * If the worker managed to start, and stop, before we got to waiting
+		 * for it we can se a STOPPED status here without it being a failure.
+		 */
+		if (DataChecksumState->success == DATACHECKSUMSWORKER_SUCCESSFUL)
+		{
+			pgstat_report_activity(STATE_IDLE, NULL);
+			LWLockAcquire(DataChecksumsWorkerLock, LW_EXCLUSIVE);
+			DataChecksumState->worker_pid = InvalidPid;
+			LWLockRelease(DataChecksumsWorkerLock);
+			return DataChecksumState->success;
+		}
+
 		ereport(WARNING,
 				errmsg("could not start background worker for enabling data checksums in database \"%s\"",
 					   db->dbname),
@@ -1595,5 +1608,7 @@ DataChecksumsWorkerMain(Datum arg)
 	/* worker done */
 	pgstat_progress_end_command();
 
+	LWLockAcquire(DataChecksumsWorkerLock, LW_EXCLUSIVE);
 	DataChecksumState->success = DATACHECKSUMSWORKER_SUCCESSFUL;
+	LWLockRelease(DataChecksumsWorkerLock);
 }


[parent: 557a9f1e3e62]