RE: [PATCH] block: Fix integer promotion error in bdrv_getlength()

[Tuguoyi]

On Wed, 2019-07-03 at 10:13 -0500, Eric Blake wrote:
> On 11/5/20 2:31 AM, Max Reitz wrote:
> > On 05.11.20 06:40, Tuguoyi wrote:
> >> As BDRV_SECTOR_SIZE is of type uint64_t, the expression will
> >> automatically convert the @ret to uint64_t. When an error code
> >> returned from bdrv_nb_sectors(), the promoted @ret will be a very
> >> large number, as a result the -EFBIG will be returned which is not the
> >> real error code.
> >>
> >> Signed-off-by: Guoyi Tu <tu.guoyi@h3c.com>
> >> ---
> >>   block.c | 2 +-
> >>   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > Thanks, applied to my block branch:
> >
> > https://git.xanclic.moe/XanClic/qemu/commits/branch/block
> >
> 
> I actually preferred the v1 solution, rather than this v2, as it avoided
> a cast.

There are several type promotion bugs(commits '570542ec') found recently, 
so i think explicitly casting the integer type can give a hint that there
is a potential type promotion if you don't do that.
 
Actually your solution look much simple and clear, and it's ok for me

--
Best regards,
Guoyi