Re: [Qemu-devel] [PATCH v3 19/19] block: look for zero blocks in bs->file

[Kevin Wolf]

Am 25.07.2013 um 16:23 hat Paolo Bonzini geschrieben:
> Reviewed-by: Eric Blake <address@hidden>
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---
>  block.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/block.c b/block.c
> index 8738937..1493f22 100644
> --- a/block.c
> +++ b/block.c
> @@ -2991,7 +2991,7 @@ static int64_t coroutine_fn 
> bdrv_co_get_block_status(BlockDriverState *bs,
>                                                       int nb_sectors, int 
> *pnum)
>  {
>      int64_t n;
> -    int64_t ret;
> +    int64_t ret, ret2;
>  
>      if (sector_num >= bs->total_sectors) {
>          *pnum = 0;
> @@ -3017,6 +3017,14 @@ static int64_t coroutine_fn 
> bdrv_co_get_block_status(BlockDriverState *bs,
>          ret |= BDRV_BLOCK_ZERO;
>      }
>  
> +    if (bs->file &&
> +        (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) &&
> +        (ret & BDRV_BLOCK_OFFSET_VALID)) {
> +        ret2 = bdrv_co_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS,
> +                                        *pnum, pnum);

Here the error check is missing, too.

> +        ret |= (ret2 & BDRV_BLOCK_ZERO);
> +    }
> +
>      return ret;
>  }

Kevin