Re: [PATCH v2 2/9] block: inline bdrv_unallocated_blocks_are_zero()

[Eric Blake <eblake@redhat.com>]

On 5/7/20 3:47 AM, Vladimir Sementsov-Ogievskiy wrote:
> The function has the only user: bdrv_co_block_status(). Inline it to

s/the only/only one/

> simplify reviewing of the following patches, which will finally drop
> unallocated_blocks_are_zero field too.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>   include/block/block.h |  1 -
>   block.c               | 15 ---------------
>   block/io.c            | 11 ++++++++---
>   3 files changed, 8 insertions(+), 19 deletions(-)
> 

> +++ b/block/io.c
> @@ -2386,15 +2386,20 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs,
>       if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) {
>           ret |= BDRV_BLOCK_ALLOCATED;
>       } else if (want_zero) {
> -        if (bdrv_unallocated_blocks_are_zero(bs)) {
> -            ret |= BDRV_BLOCK_ZERO;
> -        } else if (bs->backing) {
> +        if (bs->backing) {
>               BlockDriverState *bs2 = bs->backing->bs;
>               int64_t size2 = bdrv_getlength(bs2);
>   
>               if (size2 >= 0 && offset >= size2) {
>                   ret |= BDRV_BLOCK_ZERO;
>               }
> +        } else {
> +            BlockDriverInfo bdi;
> +            int ret2 = bdrv_get_info(bs, &bdi);
> +
> +            if (ret2 == 0 && bdi.unallocated_blocks_are_zero) {

Could perhaps condense to:

else {
     BlockDriverInfo bdi;

     if (bdrv_get_info(bs, &bd) == 0 &&
         bdi.unallocated_blocks_are_zero) {

but that's cosmetic.

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

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org