From: Fam Zheng <famz@redhat.com>
Date: Thu, 22 Aug 2013 07:36:59 +0000 (+0800)
Subject: block: better error message for read only format name
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=7780d47211bde838c7f7e9330608e5397219066e;p=qemu.git

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 bc7016a8d4..d3500c6133 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -487,7 +487,11 @@ static DriveInfo *blockdev_init(QemuOpts *all_opts,
 
         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;
         }
     }