Re: [Qemu-devel] [PATCH] block: get_block_status: use "else" when testing the opposite condition

[Fam Zheng <famz@redhat.com>]

On Thu, 05/14 12:35, Paolo Bonzini wrote:
> A bit of Boolean algebra (and common sense) tells us that the
> second "if" here is looking for blocks that are not allocated.
> This is the opposite of the "if" that sets BDRV_BLOCK_ALLOCATED,
> and thus it can use an "else".
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  block/io.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/block/io.c b/block/io.c
> index 1ce62c4..494e3b3 100644
> --- a/block/io.c
> +++ b/block/io.c
> @@ -1456,9 +1456,7 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
>  
>      if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) {
>          ret |= BDRV_BLOCK_ALLOCATED;
> -    }
> -
> -    if (!(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO)) {
> +    } else {
>          if (bdrv_unallocated_blocks_are_zero(bs)) {
>              ret |= BDRV_BLOCK_ZERO;
>          } else if (bs->backing_hd) {
> -- 
> 2.4.0
> 

Reviewed-by: Fam Zheng <famz@redhat.com>