aio: Pass result of local callbacks to ->report_return

Otherwise the results of e.g. temp table buffer verification errors will not
reach bufmgr.c. Obviously that's not right. Found while expanding the tests
for invalid buffer contents.

Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/20250326001915.bc.nmisch@google.com

3 files changed, 22 insertions, 15 deletions

diff --git a/src/backend/storage/aio/aio.c b/src/backend/storage/aio/aio.c
index 29f57f9cd1c..1fd82842718 100644
--- a/src/backend/storage/aio/aio.c
+++ b/src/backend/storage/aio/aio.c
@@ -626,13 +626,21 @@ pgaio_io_reclaim(PgAioHandle *ioh)
 
 	/*
 	 * It's a bit ugly, but right now the easiest place to put the execution
-	 * of shared completion callbacks is this function, as we need to execute
+	 * of local completion callbacks is this function, as we need to execute
 	 * local callbacks just before reclaiming at multiple callsites.
 	 */
 	if (ioh->state == PGAIO_HS_COMPLETED_SHARED)
 	{
-		pgaio_io_call_complete_local(ioh);
+		PgAioResult local_result;
+
+		local_result = pgaio_io_call_complete_local(ioh);
 		pgaio_io_update_state(ioh, PGAIO_HS_COMPLETED_LOCAL);
+
+		if (ioh->report_return)
+		{
+			ioh->report_return->result = local_result;
+			ioh->report_return->target_data = ioh->target_data;
+		}
 	}
 
 	pgaio_debug_io(DEBUG4, ioh,
@@ -642,18 +650,10 @@ pgaio_io_reclaim(PgAioHandle *ioh)
 				   ioh->distilled_result.error_data,
 				   ioh->result);
 
-	/* if the IO has been defined, we might need to do more work */
+	/* if the IO has been defined, it's on the in-flight list, remove */
 	if (ioh->state != PGAIO_HS_HANDED_OUT)
-	{
 		dclist_delete_from(&pgaio_my_backend->in_flight_ios, &ioh->node);
 
-		if (ioh->report_return)
-		{
-			ioh->report_return->result = ioh->distilled_result;
-			ioh->report_return->target_data = ioh->target_data;
-		}
-	}
-
 	if (ioh->resowner)
 	{
 		ResourceOwnerForgetAioHandle(ioh->resowner, &ioh->resowner_node);
diff --git a/src/backend/storage/aio/aio_callback.c b/src/backend/storage/aio/aio_callback.c
index 09f03f296f5..d6b53165ccf 100644
--- a/src/backend/storage/aio/aio_callback.c
+++ b/src/backend/storage/aio/aio_callback.c
@@ -262,9 +262,12 @@ pgaio_io_call_complete_shared(PgAioHandle *ioh)
  * Internal function which invokes ->complete_local for all the registered
  * callbacks.
  *
+ * Returns ioh->distilled_result after, possibly, being modified by local
+ * callbacks.
+ *
  * XXX: It'd be nice to deduplicate with pgaio_io_call_complete_shared().
  */
-void
+PgAioResult
 pgaio_io_call_complete_local(PgAioHandle *ioh)
 {
 	PgAioResult result;
@@ -296,13 +299,17 @@ pgaio_io_call_complete_local(PgAioHandle *ioh)
 
 	/*
 	 * Note that we don't save the result in ioh->distilled_result, the local
-	 * callback's result should not ever matter to other waiters.
+	 * callback's result should not ever matter to other waiters. However, the
+	 * local backend does care, so we return the result as modified by local
+	 * callbacks, which then can be passed to ioh->report_return->result.
 	 */
 	pgaio_debug_io(DEBUG3, ioh,
-				   "after local completion: distilled result: (status %s, id %u, error_data %d, result %d), raw_result: %d",
+				   "after local completion: result: (status %s, id %u, error_data %d, result %d), raw_result: %d",
 				   pgaio_result_status_string(result.status),
 				   result.id, result.error_data, result.result,
 				   ioh->result);
 
 	END_CRIT_SECTION();
+
+	return result;
 }
diff --git a/src/include/storage/aio_internal.h b/src/include/storage/aio_internal.h
index 108fe61c7b4..d5f64416870 100644
--- a/src/include/storage/aio_internal.h
+++ b/src/include/storage/aio_internal.h
@@ -309,7 +309,7 @@ extern void pgaio_shutdown(int code, Datum arg);
 /* aio_callback.c */
 extern void pgaio_io_call_stage(PgAioHandle *ioh);
 extern void pgaio_io_call_complete_shared(PgAioHandle *ioh);
-extern void pgaio_io_call_complete_local(PgAioHandle *ioh);
+extern PgAioResult pgaio_io_call_complete_local(PgAioHandle *ioh);
 
 /* aio_io.c */
 extern void pgaio_io_perform_synchronously(PgAioHandle *ioh);