Re: [Qemu-devel] [PATCHv6 14/17] block/get_block_status: fix BDRV_BLOCK_ZERO for unallocated blocks

[Paolo Bonzini]

Il 24/10/2013 08:46, Peter Lieven ha scritto:
> this patch does 2 things:
> a) only do additional call outs if BDRV_BLOCK_ZERO is not already set.
> b) use the newly introduced bdrv_has_discard_zeroes()

... whose name became bdrv_unallocated_blocks_are_zero :)  No big deal.

Paolo

> to return the
>    zero state of an unallocated block. the used callout to
>    bdrv_has_zero_init() is only valid right after bdrv_create.
> 
> Reviewed-by: Eric Blake <address@hidden>
> Signed-off-by: Peter Lieven <address@hidden>
> ---
>  block.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/block.c b/block.c
> index 21a992a..69a2d2b 100644
> --- a/block.c
> +++ b/block.c
> @@ -3263,8 +3263,8 @@ static int64_t coroutine_fn 
> bdrv_co_get_block_status(BlockDriverState *bs,
>                                       *pnum, pnum);
>      }
>  
> -    if (!(ret & BDRV_BLOCK_DATA)) {
> -        if (bdrv_has_zero_init(bs)) {
> +    if (!(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO)) {
> +        if (bdrv_unallocated_blocks_are_zero(bs)) {
>              ret |= BDRV_BLOCK_ZERO;
>          } else if (bs->backing_hd) {
>              BlockDriverState *bs2 = bs->backing_hd;
>