When dropping backup-top, we need to drain the node before freeing the
BlockCopyState. Otherwise, requests may still be in flight and then the
assertion in shres_destroy() will fail.
(This becomes visible in intermittent failure of 056.)
Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20191219182638.104621-1-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>