commit 5433c24f0f9306c82ad9bcc2b2b586e5f0ed8fa5
author Max Reitz <mreitz@redhat.com> Mon Oct 19 17:53:29 2015 +0200
committer Kevin Wolf <kwolf@redhat.com> Fri Oct 23 18:18:23 2015 +0200
tree 8b2eb29767ef12bf28d528050a0463b3e9458f5b
parent 0c3c36d651922ebe9244e68e6d9ed14cdfcac9fd

block: Prepare for NULL BDS

blk_bs() will not necessarily return a non-NULL value any more (unless
blk_is_available() is true or it can be assumed to otherwise, e.g.
because it is called immediately after a successful blk_new_with_bs() or
blk_new_open()).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block.c

diff --git a/block.c b/block.c
index e28a32a..e9f40dc 100644
--- a/block.c
+++ b/block.c
@@ -2683,6 +2683,11 @@
         blk = blk_by_name(device);
 
         if (blk) {
+            if (!blk_bs(blk)) {
+                error_setg(errp, "Device '%s' has no medium", device);
+                return NULL;
+            }
+
             return blk_bs(blk);
         }
     }