On 08/02/2013 03:02 AM, Xu Wang wrote:
> From: Xu Wang <cngesaint@gmail.com>
> 
> Every image should be checked if there is infinite loop in backing
> file chain before open it. So infinite loop check was added into
> bdrv_new_open(). If @filename is opened with no flags

s/with no flags/without the flag/

> BDRV_O_NO_BACKING, the infinite loop check should be called.
> 
> Signed-off-by: Xu Wang <cngesaint@gmail.com>
> ---
>  qemu-img.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/qemu-img.c b/qemu-img.c
> index 4f01b0a..1a63bbf 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c
> @@ -278,6 +278,13 @@ static BlockDriverState *bdrv_new_open(const char *filename,
>          drv = NULL;
>      }
>  
> +    /* check backing file loop if the whole chain need to be opened */
> +    if (!(flags & BDRV_O_NO_BACKING) &&
> +        bdrv_backing_file_loop_check(filename, fmt, NULL, NULL)) {
> +        error_report("bdrv_new_open: Open %s failed.", filename);

Error messages generally don't end with '.'; also, this message seems to
lack details that might be useful to the end user (we know that either
the backing chain couldn't be completely followed or has a loop).

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org