block: move supports_backing check to bdrv_set_file_or_backing_noperm()
Move supports_backing check of bdrv_reopen_parse_backing to called
(through bdrv_set_backing_noperm()) bdrv_set_file_or_backing_noperm()
function. The check applies to general case, so it's appropriate for
bdrv_set_file_or_backing_noperm().
We have to declare backing support for two test drivers, otherwise new
check fails.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610120537.196183-7-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block.c b/block.c
index d047cae..0a73335 100644
--- a/block.c
+++ b/block.c
@@ -3152,6 +3152,14 @@
return -EPERM;
}
+ if (is_backing && !parent_bs->drv->is_filter &&
+ !parent_bs->drv->supports_backing)
+ {
+ error_setg(errp, "Driver '%s' of node '%s' does not support backing "
+ "files", parent_bs->drv->format_name, parent_bs->node_name);
+ return -EINVAL;
+ }
+
if (parent_bs->drv->is_filter) {
role = BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY;
} else if (is_backing) {
@@ -4278,20 +4286,13 @@
}
}
- /*
- * Ensure that @bs can really handle backing files, because we are
- * about to give it one (or swap the existing one)
- */
- if (bs->drv->is_filter) {
- /* Filters always have a file or a backing child */
- if (!bs->backing) {
- error_setg(errp, "'%s' is a %s filter node that does not support a "
- "backing child", bs->node_name, bs->drv->format_name);
- return -EINVAL;
- }
- } else if (!bs->drv->supports_backing) {
- error_setg(errp, "Driver '%s' of node '%s' does not support backing "
- "files", bs->drv->format_name, bs->node_name);
+ if (bs->drv->is_filter && !bs->backing) {
+ /*
+ * Filters always have a file or a backing child, so we are trying to
+ * change wrong child
+ */
+ error_setg(errp, "'%s' is a %s filter node that does not support a "
+ "backing child", bs->node_name, bs->drv->format_name);
return -EINVAL;
}