Re: [Qemu-devel][PATCH][FIX] fix bug in block-qcow2.c:alloc_cluster_offset()

[Anthony Liguori <anthony@codemonkey.ws>]

Shahar Frank wrote:
> Hi All,
>
> During the debugging of the new revision of the zero dedup patch I
> stepped on the following bug in block-qcow2.c:alloc_cluster_offset(). I
> am not sure what the exact damage this bug can do, but it may be very
> nasty because you way not notice it effects until you will do some
> snapshot operations or similar actions that rely on the reference
> counting.
>
> The bug is easy to spot using the new "check" verb I added to the
> qemu-img in one of the previous patches. I will resend the qemu-img
> patch again with the new version of the zero dedup.
>
> Signed-off-by: Shahar Frank <shaharf@qumranet.com>
>   

Applied.  Thanks.

Regards,

Anthony Liguori

> Index: block-qcow2.c
> ===================================================================
> --- block-qcow2.c       (revision 5312)
> +++ block-qcow2.c       (working copy)
> @@ -917,7 +917,7 @@
>              /* how many free clusters ? */
>
>              while (i < nb_clusters) {
> -                cluster_offset = l2_table[l2_index + i];
> +                cluster_offset = be64_to_cpu(l2_table[l2_index + i]);
>                  if (cluster_offset != 0)
>                      break;
>                  i++;
>
>