Re: [PATCH 06/14] block-backend: use bdrv_getlength instead of blk_getlength

[Vladimir Sementsov-Ogievskiy]

On 12/13/22 11:53, Kevin Wolf wrote:
> From: Emanuele Giuseppe Esposito <eesposit@redhat.com>
>
> The only difference is that blk_ checks if the block is available,
> but this check is already performed above in blk_check_byte_request().
>
> This is in preparation for the graph rdlock, which will be taken
> by both the callers of blk_check_byte_request() and blk_getlength().
>
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>   block/block-backend.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/block/block-backend.c b/block/block-backend.c
> index 0194d86113..5b8da86772 100644
> --- a/block/block-backend.c
> +++ b/block/block-backend.c
> @@ -1253,7 +1253,7 @@ static int blk_check_byte_request(BlockBackend *blk, 
> int64_t offset,
>       }
>   
>       if (!blk->allow_write_beyond_eof) {
> -        len = blk_getlength(blk);
> +        len = bdrv_getlength(blk_bs(blk));

I understand the reasoning, but the change looks like a degradation.. bdrv_* 
functions becomes kind of *_locked() ? If we are going to introduce a lot of 
such changes, that's not good. But this one is not a problem of course.

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>

>           if (len < 0) {
>               return len;
>           }

--
Best regards,
Vladimir