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From: Peter Xu <peterx@redhat.com>
To: qemu-devel@nongnu.org
Cc: "Markus Armbruster" <armbru@redhat.com>,
	"Juraj Marcin" <jmarcin@redhat.com>,
	peterx@redhat.com,
	"Marc-André Lureau" <marcandre.lureau@redhat.com>,
	"Fabiano Rosas" <farosas@suse.de>,
	"Daniel P . Berrangé" <berrange@redhat.com>,
	"Vladimir Sementsov-Ogievskiy" <vsementsov@yandex-team.ru>
Subject: [PATCH for-11.0 1/6] migration: Use explicit error_free() instead of g_autoptr
Date: Tue, 25 Nov 2025 15:46:43 -0500	[thread overview]
Message-ID: <20251125204648.857018-2-peterx@redhat.com> (raw)
In-Reply-To: <20251125204648.857018-1-peterx@redhat.com>

There're only two use cases of g_autoptr to free Error objects in migration
code paths.

Due to the nature of how Error should be used (normally ownership will be
passed over to Error APIs, like error_report_err), auto-free functions may
be error prone on its own.  The auto cleanup function was accidentally
merged as pointed out by Dan and Markus:

https://lore.kernel.org/r/aSWSLMi6ZhTCS_p2@redhat.com

Remove the two use cases so that we can remove the auto cleanup function,
hence suggest to not use auto frees for Errors.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 migration/multifd-device-state.c | 3 ++-
 migration/savevm.c               | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/migration/multifd-device-state.c b/migration/multifd-device-state.c
index fce64f00b0..db3239fef5 100644
--- a/migration/multifd-device-state.c
+++ b/migration/multifd-device-state.c
@@ -140,7 +140,7 @@ static void multifd_device_state_save_thread_data_free(void *opaque)
 static int multifd_device_state_save_thread(void *opaque)
 {
     SaveCompletePrecopyThreadData *data = opaque;
-    g_autoptr(Error) local_err = NULL;
+    Error *local_err = NULL;
 
     if (!data->hdlr(data, &local_err)) {
         MigrationState *s = migrate_get_current();
@@ -159,6 +159,7 @@ static int multifd_device_state_save_thread(void *opaque)
          * return we end setting is purely arbitrary.
          */
         migrate_set_error(s, local_err);
+        error_free(local_err);
     }
 
     return 0;
diff --git a/migration/savevm.c b/migration/savevm.c
index 62cc2ce25c..638e9b364f 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2823,7 +2823,7 @@ static int qemu_loadvm_load_thread(void *thread_opaque)
 {
     struct LoadThreadData *data = thread_opaque;
     MigrationIncomingState *mis = migration_incoming_get_current();
-    g_autoptr(Error) local_err = NULL;
+    Error *local_err = NULL;
 
     if (!data->function(data->opaque, &mis->load_threads_abort, &local_err)) {
         MigrationState *s = migrate_get_current();
@@ -2841,6 +2841,7 @@ static int qemu_loadvm_load_thread(void *thread_opaque)
          * return we end setting is purely arbitrary.
          */
         migrate_set_error(s, local_err);
+        error_free(local_err);
     }
 
     return 0;
-- 
2.50.1



  reply	other threads:[~2025-11-25 20:48 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-11-25 20:46 [PATCH for-11.0 0/6] migration: Error reporting cleanups Peter Xu
2025-11-25 20:46 ` Peter Xu [this message]
2025-11-26  6:43   ` [PATCH for-11.0 1/6] migration: Use explicit error_free() instead of g_autoptr Markus Armbruster
2025-11-25 20:46 ` [PATCH for-11.0 2/6] Revert "error: define g_autoptr() cleanup function for the Error type" Peter Xu
2025-11-26  6:45   ` Markus Armbruster
2025-11-26  7:43   ` Cédric Le Goater
2025-11-26  8:08     ` Markus Armbruster
2025-11-26 14:34   ` [PATCH 2.5/6] error: Explain why we don't g_autoptr(Error) Markus Armbruster
2025-11-26 15:14     ` Cédric Le Goater
2025-11-26 16:18       ` Peter Xu
2025-11-27  7:01         ` Markus Armbruster
2025-11-26 20:21   ` [PATCH for-11.0 2/6] Revert "error: define g_autoptr() cleanup function for the Error type" Maciej S. Szmigiero
2025-11-27  7:10   ` [PATCH 2.5/6] error: Poison g_autoptr(Error) to prevent its use Markus Armbruster
2025-11-27 15:34     ` Cédric Le Goater
2025-11-25 20:46 ` [PATCH for-11.0 3/6] migration: Make migration_connect_set_error() own the error Peter Xu
2025-11-26  7:27   ` Markus Armbruster
2025-11-28 16:58     ` Peter Xu
2025-11-25 20:46 ` [PATCH for-11.0 4/6] migration: Make multifd_send_set_error() " Peter Xu
2025-11-26  7:30   ` Markus Armbruster
2025-11-26  7:32     ` Markus Armbruster
2025-11-25 20:46 ` [PATCH for-11.0 5/6] migration: Make multifd_recv_terminate_threads() " Peter Xu
2025-11-25 20:46 ` [PATCH for-11.0 6/6] migration: Replace migrate_set_error() with migrate_error_propagate() Peter Xu
2025-11-26  7:57   ` Markus Armbruster
2025-12-01 17:32     ` Peter Xu

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