[PULL 37/38] migration/multifd: Unify multifd_send_thread error paths

[Juan Quintela]

From: Fabiano Rosas <farosas@suse.de>

The preferred usage of the Error type is to always set both the return
code and the error when a failure happens. As all code called from the
send thread follows this pattern, we'll always have the return code
and the error set at the same time.

Aside from the convention, in this piece of code this must be the
case, otherwise the if (ret != 0) would be exiting the thread without
calling multifd_send_terminate_threads() which is incorrect.

Unify both paths to make it clear that both are taken when there's an
error.

Signed-off-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231012134343.23757-3-farosas@suse.de>
---
 migration/multifd.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/migration/multifd.c b/migration/multifd.c
index 8e9a5ee394..c92955de41 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -753,19 +753,13 @@ static void *multifd_send_thread(void *opaque)
     }
 
 out:
-    if (local_err) {
+    if (ret) {
+        assert(local_err);
         trace_multifd_send_error(p->id);
         multifd_send_terminate_threads(local_err);
-        error_free(local_err);
-    }
-
-    /*
-     * Error happen, I will exit, but I can't just leave, tell
-     * who pay attention to me.
-     */
-    if (ret != 0) {
         qemu_sem_post(&p->sem_sync);
         qemu_sem_post(&multifd_send_state->channels_ready);
+        error_free(local_err);
     }
 
     qemu_mutex_lock(&p->mutex);
-- 
2.41.0