[PATCH 2/3] job: use complete(do_graph_change=false) to handle soft cancel

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

Soft cancel of READY mirror is more like completion than cancelling. We
have bugs and misunderstanding because of this feature. Now, let's
handle it the other way to drop force cancelling at all in the
following commit.

This makes internal implementation cleaner. Still, we should deprecate
and drop old interface (through block-job-cancel) as a separate step.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 blockdev.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/blockdev.c b/blockdev.c
index 3d8ac368a1..c4ee5f02f4 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3366,7 +3366,16 @@ void qmp_block_job_cancel(const char *device,
     }
 
     trace_qmp_block_job_cancel(job);
-    job_user_cancel(&job->job, force, errp);
+    if (!force && job_is_ready(&job->job)) {
+        /*
+         * Hack to support old mirror soft-cancel. Please add new API to do
+         * complete with disabled graph-change, deprecate soft-cancel and
+         * finally drop this code.
+         */
+        job_complete_ex(&job->job, false, errp);
+    } else {
+        job_user_cancel(&job->job, force, errp);
+    }
 out:
     aio_context_release(aio_context);
 }
-- 
2.29.2