block: Open by reference will try device then node_name.

Since we introduced node_name for named bs of the graph modify the opening by
reference to use it as a fallback.

This patch also enforce the separation of the device id and graph node
namespaces.

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/block.c b/block.c
index ba2aecf87a..8f718f9f29 100644
--- a/block.c
+++ b/block.c
@@ -796,6 +796,13 @@ static int bdrv_assign_node_name(BlockDriverState *bs,
         return -EINVAL;
     }
 
+    /* takes care of avoiding namespaces collisions */
+    if (bdrv_find(node_name)) {
+        error_setg(errp, "node-name=%s is conflicting with a device id",
+                   node_name);
+        return -EINVAL;
+    }
+
     /* takes care of avoiding duplicates node names */
     if (bdrv_find_node(node_name)) {
         error_setg(errp, "Duplicate node name");
@@ -977,9 +984,8 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename,
         }
         QDECREF(options);
 
-        bs = bdrv_find(reference);
+        bs = bdrv_lookup_bs(reference, reference, errp);
         if (!bs) {
-            error_setg(errp, "Cannot find block device '%s'", reference);
             return -ENODEV;
         }
         bdrv_ref(bs);