blockjob: Add "completed" and "ret" in BlockJob

They are set when block_job_completed is called.
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Message-id: 1446765200-3054-8-git-send-email-jsnow@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

blockjob.c

@@ -99,6 +99,9 @@ void block_job_completed(BlockJob *job, int ret)
     BlockDriverState *bs = job->bs;
 
     assert(bs->job == job);
+    assert(!job->completed);
+    job->completed = true;
+    job->ret = ret;
     job->cb(job->opaque, ret);
     block_job_unref(job);
 }

include/block/blockjob.h

@@ -153,6 +153,15 @@ struct BlockJob {
 
     /** Reference count of the block job */
     int refcnt;
+
+    /* True if this job has reported completion by calling block_job_completed.
+     */
+    bool completed;
+
+    /* ret code passed to block_job_completed.
+     */
+    int ret;
+
 };
 
 /**