qemu: block: store and test driver names for detected storage nodes

Store the 'drv' field both for the storage node and for the format node
and format them in the test case.
Reviewed-by: NEric Blake <eblake@redhat.com>

src/qemu/qemu_block.c

@@ -56,6 +56,9 @@ qemuBlockNodeNameBackingChainDataFree(qemuBlockNodeNameBackingChainDataPtr data)
 
     VIR_FREE(data->qemufilename);
 
+    VIR_FREE(data->drvformat);
+    VIR_FREE(data->drvstorage);
+
     qemuBlockNodeNameBackingChainDataFree(data->backing);
 
     VIR_FREE(data);
@@ -108,7 +111,8 @@ qemuBlockNodeNameGetBackingChainBacking(virJSONValuePtr next,
     virJSONValuePtr parentnodedata;
     virJSONValuePtr nodedata;
     const char *nodename = virJSONValueObjectGetString(next, "node-name");
-    const char *drvname;
+    const char *drvname = NULL;
+    const char *drvparent = NULL;
     const char *parentnodename = NULL;
     const char *filename = NULL;
     int ret = -1;
@@ -134,8 +138,10 @@ qemuBlockNodeNameGetBackingChainBacking(virJSONValuePtr next,
 
     if (parent &&
         (parentnodename = virJSONValueObjectGetString(parent, "node-name"))) {
-        if ((parentnodedata = virHashLookup(nodenamestable, parentnodename)))
+        if ((parentnodedata = virHashLookup(nodenamestable, parentnodename))) {
             filename = virJSONValueObjectGetString(parentnodedata, "file");
+            drvparent = virJSONValueObjectGetString(parentnodedata, "drv");
+        }
     }
 
     if (VIR_ALLOC(data) < 0)
@@ -143,7 +149,9 @@ qemuBlockNodeNameGetBackingChainBacking(virJSONValuePtr next,
 
     if (VIR_STRDUP(data->nodeformat, nodename) < 0 ||
         VIR_STRDUP(data->nodestorage, parentnodename) < 0 ||
-        VIR_STRDUP(data->qemufilename, filename) < 0)
+        VIR_STRDUP(data->qemufilename, filename) < 0 ||
+        VIR_STRDUP(data->drvformat, drvname) < 0 ||
+        VIR_STRDUP(data->drvstorage, drvparent) < 0)
         goto cleanup;
 
     if (backing &&

src/qemu/qemu_block.h

@@ -35,6 +35,10 @@ struct qemuBlockNodeNameBackingChainData {
     char *nodestorage;  /* node name of the storage backing the format node */
 
     qemuBlockNodeNameBackingChainDataPtr backing;
+
+    /* for testing purposes */
+    char *drvformat;
+    char *drvstorage;
 };
 
 virHashTablePtr

tests/qemumonitorjsondata/qemumonitorjson-nodename-basic.result

 drive-virtio-disk0
 filename    : '/var/lib/libvirt/images/rhel7.3.1483545313'
 format node : '#block187'
+format drv  : 'qcow2'
 storage node: '#block033'
+storage drv : 'file'
   filename    : '/var/lib/libvirt/images/rhel7.3.1483536402'
   format node : '#block306'
+  format drv  : 'qcow2'
   storage node: '#block220'
+  storage drv : 'file'
     filename    : '/var/lib/libvirt/images/rhel7.3.qcow2'
     format node : '#block558'
+    format drv  : 'qcow2'
     storage node: '#block481'
+    storage drv : 'file'

tests/qemumonitorjsontest.c

@@ -2714,8 +2714,10 @@ testBlockNodeNameDetectFormat(void *payload,
         virBufferAsprintf(buf, "filename    : '%s'\n", entry->qemufilename);
         virBufferAsprintf(buf, "format node : '%s'\n",
                           NULLSTR(entry->nodeformat));
+        virBufferAsprintf(buf, "format drv  : '%s'\n", NULLSTR(entry->drvformat));
         virBufferAsprintf(buf, "storage node: '%s'\n",
                           NULLSTR(entry->nodestorage));
+        virBufferAsprintf(buf, "storage drv : '%s'\n", NULLSTR(entry->drvstorage));
 
         virBufferAdjustIndent(buf, 2);