From 0ed4b7e81898ee7003aee3488a0fa693474a0890 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Mon, 12 Jun 2017 13:33:33 +0200
Subject: [PATCH 07/13] commit: Fix completion with extra reference

RH-Author: Kevin Wolf <kwolf@redhat.com>
Message-id: <1497274415-4884-2-git-send-email-kwolf@redhat.com>
Patchwork-id: 75588
O-Subject: [RHEL-7.4 qemu-kvm-rhev PATCH 1/3] commit: Fix completion with extra reference
Bugzilla: 1453169
RH-Acked-by: Max Reitz <mreitz@redhat.com>
RH-Acked-by: Jeffrey Cody <jcody@redhat.com>
RH-Acked-by: John Snow <jsnow@redhat.com>

commit_complete() can't assume that after its block_job_completed() the
job is actually immediately freed; someone else may still be holding
references. In this case, the op blockers on the intermediate nodes make
the graph reconfiguration in the completion code fail.

Call block_job_remove_all_bdrv() manually so that we know for sure that
any blockers on intermediate nodes are given up.

Upstream status: Applied to git://repo.or.cz/qemu/kevin.git block
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 block/commit.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/block/commit.c b/block/commit.c
index 3bae46e..fba25e2 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -119,6 +119,13 @@ static void commit_complete(BlockJob *job, void *opaque)
     }
     g_free(s->backing_file_str);
     blk_unref(s->top);
+
+    /* If there is more than one reference to the job (e.g. if called from
+     * block_job_finish_sync()), block_job_completed() won't free it and
+     * therefore the blockers on the intermediate nodes remain. This would
+     * cause bdrv_set_backing_hd() to fail. */
+    block_job_remove_all_bdrv(job);
+
     block_job_completed(&s->common, ret);
     g_free(data);
 
-- 
1.8.3.1