block: better error message for read only format name
When user tries to use read-only whitelist format in the command line
option, failure message was "'foo' invalid format". It might be invalid
only for writable, but valid for read-only, so it is confusing. Give the
user easier to understand information.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/blockdev.c b/blockdev.c
index bc7016a..d3500c6 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -487,7 +487,11 @@
drv = bdrv_find_whitelisted_format(buf, ro);
if (!drv) {
- error_report("'%s' invalid format", buf);
+ if (!ro && bdrv_find_whitelisted_format(buf, !ro)) {
+ error_report("'%s' can be only used as read-only device.", buf);
+ } else {
+ error_report("'%s' invalid format", buf);
+ }
return NULL;
}
}
