blockjob: assert(cb) when create job

Callback for block job should always exist

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 1466672241-22485-2-git-send-email-xiecl.fnst@cn.fujitsu.com
Signed-off-by: Jeff Cody <jcody@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/blockjob.c b/blockjob.c
index 90c4e26..205da9d 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -110,6 +110,7 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
     BlockBackend *blk;
     BlockJob *job;
 
+    assert(cb);
     if (bs->job) {
         error_setg(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
         return NULL;