blockjob: Add permissions to block_job_add_bdrv()

Block jobs don't actually do I/O through the the reference they create
with block_job_add_bdrv(), but they might want to use the permisssion
system to express what the block job does to intermediate nodes. This
adds permissions to block_job_add_bdrv() to provide the means to request
permissions.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
diff --git a/block/mirror.c b/block/mirror.c
index 18128e6..4d325f1 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1052,13 +1052,18 @@
         return;
     }
 
-    block_job_add_bdrv(&s->common, target);
+    /* FIXME Use real permissions */
+    block_job_add_bdrv(&s->common, "target", target, 0, BLK_PERM_ALL,
+                       &error_abort);
+
     /* In commit_active_start() all intermediate nodes disappear, so
      * any jobs in them must be blocked */
     if (bdrv_chain_contains(bs, target)) {
         BlockDriverState *iter;
         for (iter = backing_bs(bs); iter != target; iter = backing_bs(iter)) {
-            block_job_add_bdrv(&s->common, iter);
+            /* FIXME Use real permissions */
+            block_job_add_bdrv(&s->common, "intermediate node", iter, 0,
+                               BLK_PERM_ALL, &error_abort);
         }
     }