[Qemu-devel] [PATCH 1/6] block: do not probe zero-sized disks

[Kevin Wolf <kwolf@redhat.com>]

From: Paolo Bonzini <pbonzini@redhat.com>

A blank CD or DVD is visible as a zero-sized disks.  Probing such
disks will lead to an EIO and a failure to start the VM.  Treating
them as raw is a better solution.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/block.c b/block.c
index 60873ea..14f8202 100644
--- a/block.c
+++ b/block.c
@@ -527,7 +527,7 @@ static int find_image_format(BlockDriverState *bs, const char *filename,
     int ret = 0;
 
     /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
-    if (bs->sg || !bdrv_is_inserted(bs)) {
+    if (bs->sg || !bdrv_is_inserted(bs) || bdrv_getlength(bs) == 0) {
         drv = bdrv_find_format("raw");
         if (!drv) {
             ret = -ENOENT;
-- 
1.7.6.5