Re: [Qemu-devel] [PATCH for-2.1] block: Fix bdrv_is_allocated() return value

[Eric Blake <eblake@redhat.com>]

[-- Attachment #1: Type: text/plain, Size: 1146 bytes --]

On 07/07/2014 09:37 AM, Kevin Wolf wrote:
> bdrv_is_allocated() should return either 0 or 1 in successful cases.
> We're lucky that currently, the callers that rely on this (e.g. because
> they check for ret == 1) don't seem to break badly. They just might skip
> some optimisation or in the case of qemu-io 'map' print separate lines
> where a single line would suffice. In theory, a wrong allocation status
> could lead to image corruption with certain operations, so let's fix
> this quickly.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  block.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/block.c b/block.c
> index f80e2b2..e2e9cbb 100644
> --- a/block.c
> +++ b/block.c
> @@ -4039,7 +4039,7 @@ int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num,
>      if (ret < 0) {
>          return ret;
>      }
> -    return (ret & BDRV_BLOCK_ALLOCATED);
> +    return !!(ret & BDRV_BLOCK_ALLOCATED);

Reviewed-by: Eric Blake <eblake@redhat.com>

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


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 604 bytes --]