qemu: command: Call qemuGetDriveSourceProps only if necessary

Add logic which will call qemuGetDriveSourceProps only in cases where we
need the JSON representation. This will allow qemuGetDriveSourceProps to
generate the JSON representation for all possible disk sources.

src/qemu/qemu_command.c

@@ -1436,6 +1436,28 @@ qemuDiskBusNeedsDeviceArg(int bus)
 }
 
 
+/**
+ * qemuDiskSourceNeedsProps:
+ * @src: disk source
+ *
+ * Returns true, if the disk source needs to be generated from the JSON
+ * representation. Otherwise, the disk source should be represented using
+ * the legacy representation.
+ */
+static bool
+qemuDiskSourceNeedsProps(virStorageSourcePtr src)
+{
+    int actualType = virStorageSourceGetActualType(src);
+
+    if (actualType == VIR_STORAGE_TYPE_NETWORK &&
+        src->protocol == VIR_STORAGE_NET_PROTOCOL_GLUSTER &&
+        src->nhosts > 1)
+        return true;
+
+    return false;
+}
+
+
 static int
 qemuBuildDriveSourceStr(virDomainDiskDefPtr disk,
                         virQEMUDriverConfigPtr cfg,
@@ -1450,7 +1472,8 @@ qemuBuildDriveSourceStr(virDomainDiskDefPtr disk,
     char *source = NULL;
     int ret = -1;
 
-    if (qemuGetDriveSourceProps(disk->src, &srcprops) < 0)
+    if (qemuDiskSourceNeedsProps(disk->src) &&
+        qemuGetDriveSourceProps(disk->src, &srcprops) < 0)
         goto cleanup;
 
     if (!srcprops &&