Re: [Qemu-devel] [PATCH for-2.10] block/qapi: Remove redundat NULL check to silence Coverity

[Philippe Mathieu-Daudé]

On 07/31/2017 11:38 AM, Jeff Cody wrote:
> On Mon, Jul 31, 2017 at 02:51:11PM +0200, Kevin Wolf wrote:
> > When skipping implicit nodes in bdrv_block_device_info(), we know that
> > bs0 is always non-NULL; initially, because it's taken from a BdrvChild
>
> Not to mention, we deference bs0 in the chunk of code right above this, so
> we'd segfault anyway if the initial value was NULL.

Yes, please move your assert before:

137:    if (bs0->drv && bs0->backing) {

Once there:
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

> > and a BdrvChild never has a NULL bs, and after the first iteration
> > because implicit nodes always have a backing file.
> >
> > Remove the NULL check and add an assertion that the implicit node does
> > indeed have a backing file.
> >
> > Signed-off-by: Kevin Wolf <address@hidden>
>
>
> Reviewed-by: Jeff Cody <address@hidden>
>
>
>
> > ---
> >   block/qapi.c | 3 ++-
> >   1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/block/qapi.c b/block/qapi.c
> > index d2b18ee9df..5f1a71f5d2 100644
> > --- a/block/qapi.c
> > +++ b/block/qapi.c
> > @@ -145,8 +145,9 @@ BlockDeviceInfo *bdrv_block_device_info(BlockBackend *blk,
> >   
> >           /* Skip automatically inserted nodes that the user isn't aware of for
> >            * query-block (blk != NULL), but not for query-named-block-nodes */
> > -        while (blk && bs0 && bs0->drv && bs0->implicit) {
> > +        while (blk && bs0->drv && bs0->implicit) {
> >               bs0 = backing_bs(bs0);
> > +            assert(bs0);
> >           }
> >       }
> >   
> > --
> > 2.13.3