block: Simplify drive-mirror

Now that we can support boxed commands, use it to greatly
reduce the number of parameters (and likelihood of getting
out of sync) when adjusting drive-mirror parameters.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-Id: <1468535878-3760-1-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
diff --git a/hmp.c b/hmp.c
index ea17d49..cc2056e 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1077,31 +1077,28 @@
 
 void hmp_drive_mirror(Monitor *mon, const QDict *qdict)
 {
-    const char *device = qdict_get_str(qdict, "device");
     const char *filename = qdict_get_str(qdict, "target");
     const char *format = qdict_get_try_str(qdict, "format");
     bool reuse = qdict_get_try_bool(qdict, "reuse", false);
     bool full = qdict_get_try_bool(qdict, "full", false);
-    enum NewImageMode mode;
     Error *err = NULL;
+    DriveMirror mirror = {
+        .device = (char *)qdict_get_str(qdict, "device"),
+        .target = (char *)filename,
+        .has_format = !!format,
+        .format = (char *)format,
+        .sync = full ? MIRROR_SYNC_MODE_FULL : MIRROR_SYNC_MODE_TOP,
+        .has_mode = true,
+        .mode = reuse ? NEW_IMAGE_MODE_EXISTING : NEW_IMAGE_MODE_ABSOLUTE_PATHS,
+        .unmap = true,
+    };
 
     if (!filename) {
         error_setg(&err, QERR_MISSING_PARAMETER, "target");
         hmp_handle_error(mon, &err);
         return;
     }
-
-    if (reuse) {
-        mode = NEW_IMAGE_MODE_EXISTING;
-    } else {
-        mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
-    }
-
-    qmp_drive_mirror(false, NULL, device, filename, !!format, format,
-                     false, NULL, false, NULL,
-                     full ? MIRROR_SYNC_MODE_FULL : MIRROR_SYNC_MODE_TOP,
-                     true, mode, false, 0, false, 0, false, 0,
-                     false, 0, false, 0, false, true, &err);
+    qmp_drive_mirror(&mirror, &err);
     hmp_handle_error(mon, &err);
 }