[PULL 11/12] migration/colo.c: Move colo_notify_compares_event to the right place

["Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>]

From: Lukas Straub <lukasstraub2@web.de>

If the secondary has to failover during checkpointing, it still is
in the old state (i.e. different state than primary). Thus we can't
expose the primary state until after the checkpoint is sent.

This fixes sporadic connection reset of client connections during
failover.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Message-Id: <d4555dd5146a54518c4d9d4efd996b7c745c6687.1589193382.git.lukasstraub2@web.de>
Reviewed-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/colo.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/migration/colo.c b/migration/colo.c
index 59639f519f..ea7d1e9d4e 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -436,12 +436,6 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
         goto out;
     }
 
-    qemu_event_reset(&s->colo_checkpoint_event);
-    colo_notify_compares_event(NULL, COLO_EVENT_CHECKPOINT, &local_err);
-    if (local_err) {
-        goto out;
-    }
-
     /* Disable block migration */
     migrate_set_block_enabled(false, &local_err);
     if (local_err) {
@@ -503,6 +497,12 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
         goto out;
     }
 
+    qemu_event_reset(&s->colo_checkpoint_event);
+    colo_notify_compares_event(NULL, COLO_EVENT_CHECKPOINT, &local_err);
+    if (local_err) {
+        goto out;
+    }
+
     colo_receive_check_message(s->rp_state.from_dst_file,
                        COLO_MESSAGE_VMSTATE_LOADED, &local_err);
     if (local_err) {
-- 
2.26.2