qapi: Add "backing" to BlockStats

Currently there is no way to query BlockStats of the backing chain. This
adds "backing" field into BlockStats to make it possible.

The comment of "parent" is reworded.

Signed-off-by: Fam Zheng <[email protected]>
Reviewed-by: Benoit Canet <[email protected]>
Reviewed-by: Eric Blake <[email protected]>
Signed-off-by: Kevin Wolf <[email protected]>

diff --git a/block/qapi.c b/block/qapi.c
index a32cb79db8e020cfe16aceb2309b423ac5490168..98b1b83bd6a08e54b7249119e5bb9e1fde59ebc9 100644 (file)
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -318,6 +318,11 @@ BlockStats *bdrv_query_stats(const BlockDriverState *bs)
         s->parent = bdrv_query_stats(bs->file);
     }
 
+    if (bs->backing_hd) {
+        s->has_backing = true;
+        s->backing = bdrv_query_stats(bs->backing_hd);
+    }
+
     return s;
 }
 

diff --git a/qapi-schema.json b/qapi-schema.json
index 35f7b34410fa6cc16400593d809763ceb6d0dc14..a433869962c641293f99ed2718915bd0a412e075 100644 (file)
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1022,15 +1022,17 @@
 #
 # @stats:  A @BlockDeviceStats for the device.
 #
-# @parent: #optional This may point to the backing block device if this is a
-#          a virtual block device.  If it's a backing block, this will point
-#          to the backing file is one is present.
+# @parent: #optional This describes the file block device if it has one.
+#
+# @backing: #optional This describes the backing block device if it has one.
+#           (Since 2.0)
 #
 # Since: 0.14.0
 ##
 { 'type': 'BlockStats',
   'data': {'*device': 'str', 'stats': 'BlockDeviceStats',
-           '*parent': 'BlockStats'} }
+           '*parent': 'BlockStats',
+           '*backing': 'BlockStats'} }
 
 ##
 # @query-blockstats: