[PATCH 2/2] migration: Fix return-path thread exit

["Cédric Le Goater" <clg@redhat.com>]

In case of error, close_return_path_on_source() can perform a shutdown
to exit the return-path thread.  However, in migrate_fd_cleanup(),
'to_dst_file' is closed before calling close_return_path_on_source()
and the shutdown fails, leaving the source and destination waiting for
an event to occur.

Close the file after calling close_return_path_on_source() so that the
shutdown succeeds and the return-path thread exits.

Signed-off-by: Cédric Le Goater <clg@redhat.com>
---
 migration/migration.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/migration/migration.c b/migration/migration.c
index 2c3362235c7651c11d581f3c3639571f1f9636ef..1e0b6acaedc272e8ce26ad40be2c42177f5fd14e 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1314,6 +1314,7 @@ void migrate_set_state(int *state, int old_state, int new_state)
 static void migrate_fd_cleanup(MigrationState *s)
 {
     int file_error = 0;
+    QEMUFile *tmp = NULL;
 
     g_free(s->hostname);
     s->hostname = NULL;
@@ -1323,8 +1324,6 @@ static void migrate_fd_cleanup(MigrationState *s)
     qemu_savevm_state_cleanup();
 
     if (s->to_dst_file) {
-        QEMUFile *tmp;
-
         trace_migrate_fd_cleanup();
         bql_unlock();
         if (s->migration_thread_running) {
@@ -1344,15 +1343,14 @@ static void migrate_fd_cleanup(MigrationState *s)
          * critical section won't block for long.
          */
         migration_ioc_unregister_yank_from_file(tmp);
-        qemu_fclose(tmp);
     }
 
-    /*
-     * We already cleaned up to_dst_file, so errors from the return
-     * path might be due to that, ignore them.
-     */
     close_return_path_on_source(s, file_error);
 
+    if (tmp) {
+        qemu_fclose(tmp);
+    }
+
     assert(!migration_is_active(s));
 
     if (s->state == MIGRATION_STATUS_CANCELLING) {
-- 
2.43.0