qmp: Allow block_resize to manipulate bs graph nodes.

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

blockdev.c

@@ -1683,14 +1683,24 @@ int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
     return 0;
 }
 
-void qmp_block_resize(const char *device, int64_t size, Error **errp)
+void qmp_block_resize(bool has_device, const char *device,
+                      bool has_node_name, const char *node_name,
+                      int64_t size, Error **errp)
 {
+    Error *local_err = NULL;
     BlockDriverState *bs;
     int ret;
 
-    bs = bdrv_find(device);
+    bs = bdrv_lookup_bs(has_device ? device : NULL,
-    if (!bs) {
+                        has_node_name ? node_name : NULL,
-        error_set(errp, QERR_DEVICE_NOT_FOUND, device);
+                        &local_err);
+    if (error_is_set(&local_err)) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    if (!bdrv_is_first_non_filter(bs)) {
+        error_set(errp, QERR_FEATURE_DISABLED, "resize");
         return;
     }
 

hmp.c

@@ -893,7 +893,7 @@ void hmp_block_resize(Monitor *mon, const QDict *qdict)
     int64_t size = qdict_get_int(qdict, "size");
     Error *errp = NULL;
 
-    qmp_block_resize(device, size, &errp);
+    qmp_block_resize(true, device, false, NULL, size, &errp);
     hmp_handle_error(mon, &errp);
 }
 

qapi-schema.json

@@ -1724,7 +1724,11 @@
 #
 # Resize a block image while a guest is running.
 #
-# @device:  the name of the device to get the image resized
+# Either @device or @node-name must be set but not both.
+#
+# @device: #optional the name of the device to get the image resized
+#
+# @node-name: #optional graph node name to get the image resized (Since 2.0)
 #
 # @size:  new image size in bytes
 #
@@ -1733,7 +1737,9 @@
 #
 # Since: 0.14.0
 ##
-{ 'command': 'block_resize', 'data': { 'device': 'str', 'size': 'int' }}
+{ 'command': 'block_resize', 'data': { '*device': 'str',
+                                       '*node-name': 'str',
+                                       'size': 'int' }}
 
 ##
 # @NewImageMode

qmp-commands.hx

@@ -931,7 +931,7 @@ EQMP
 
     {
         .name       = "block_resize",
-        .args_type  = "device:B,size:o",
+        .args_type  = "device:s?,node-name:s?,size:o",
         .mhandler.cmd_new = qmp_marshal_input_block_resize,
     },
 
@@ -944,6 +944,7 @@ Resize a block image while a guest is running.
 Arguments:
 
 - "device": the device's ID, must be unique (json-string)
+- "node-name": the node name in the block driver state graph (json-string)
 - "size": new size
 
 Example: