aio: Fix configuration reload in IO workers.

macdice · macdice · commit 7d11f36e71a9 · 2025-07-12T16:34:06.000+12:00
method_worker.c installed SignalHandlerForConfigReload, but it failed to actually process reload requests. That hasn't yet produced any concrete problem reports in terms of GUC changes it should have cared about in v18, but it was inconsistent. It did cause problems for a couple of patches in development that need IO workers to react to ALTER SYSTEM + pg_reload_conf(). Fix extracted from one of those patches. Back-patch to 18. Reported-by: Dmitry Dolgov <9erthalion6@gmail.com> Discussion: https://postgr.es/m/sh5uqe4a4aqo5zkkpfy5fobe2rg2zzouctdjz7kou4t74c66ql%40yzpkxb7pgoxf
diff --git a/src/backend/storage/aio/method_worker.c b/src/backend/storage/aio/method_worker.c
@@ -575,6 +575,12 @@ IoWorkerMain(const void *startup_data, size_t startup_data_len)
 		}
 
 		CHECK_FOR_INTERRUPTS();
+
+		if (ConfigReloadPending)
+		{
+			ConfigReloadPending = false;
+			ProcessConfigFile(PGC_SIGHUP);
+		}
 	}
 
 	error_context_stack = errcallback.previous;

Original file line number	Diff line number	Diff line change
`@@ -575,6 +575,12 @@ IoWorkerMain(const void *startup_data, size_t startup_data_len)`
`575`	`575`	`}`
`576`	`576`
`577`	`577`	`CHECK_FOR_INTERRUPTS();`
	`578`	`+`
	`579`	`+ if (ConfigReloadPending)`
	`580`	`+ {`
	`581`	`+ ConfigReloadPending = false;`
	`582`	`+ ProcessConfigFile(PGC_SIGHUP);`
	`583`	`+ }`
`578`	`584`	`}`
`579`	`585`
`580`	`586`	`error_context_stack = errcallback.previous;`