Re: [PATCH v5 01/14] block: return status from bdrv_append and friends

[Vladimir Sementsov-Ogievskiy]

12.01.2021 20:27, Alberto Garcia wrote:
> On Sat 09 Jan 2021 01:57:58 PM CET, Vladimir Sementsov-Ogievskiy wrote:
> > -void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
> > +int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
> >                            Error **errp)
>
> The indentation of the second line should be adjusted, shouldn't it?
>
> >   {
> > +    int ret;
> >       bool update_inherits_from = bdrv_chain_contains(bs, backing_hd) &&
> >           bdrv_inherits_from_recursive(backing_hd, bs);
> >   
> >       if (bdrv_is_backing_chain_frozen(bs, child_bs(bs->backing), errp)) {
> > -        return;
> > +        return -EPERM;
> >       }
> >   
> >       if (backing_hd) {
> > @@ -2853,15 +2854,24 @@ void bdrv_set_backing_hd(BlockDriverState *bs, 
> > BlockDriverState *backing_hd,
> >
> >       bs->backing = bdrv_attach_child(bs, backing_hd, "backing", &child_of_bds,
> >                                       bdrv_backing_role(bs), errp);
> > +    if (!bs->backing) {
> > +        ret = -EPERM;
> > +        goto out;
> > +    }
>
> This is not visible in the patch, but before the bdrv_attach_child()
> call there's this:
>
>      if (!backing_hd) {
>          goto out;
>      }
>
> But in this case 'ret' is still uninitialized.
>
> >   out:
> >       bdrv_refresh_limits(bs, NULL);
> > +
> > +    return ret;
> >   }
>
>
>
> > -static void bdrv_replace_node_common(BlockDriverState *from,
> > -                                     BlockDriverState *to,
> > -                                     bool auto_skip, Error **errp)
> > +static int bdrv_replace_node_common(BlockDriverState *from,
> > +                                    BlockDriverState *to,
> > +                                    bool auto_skip, Error **errp)
> >   {
> >       BdrvChild *c, *next;
> >       GSList *list = NULL, *p;
> > @@ -4562,6 +4572,7 @@ static void bdrv_replace_node_common(BlockDriverState 
> > *from,
> >               goto out;
> >           }
> >           if (c->frozen) {
> > +            ret = -EPERM;
> >               error_setg(errp, "Cannot change '%s' link to '%s'",
> >                          c->name, from->node_name);
> >               goto out;
>
> Same here, you set 'ret' in the second 'goto out' but not in the first.
Oops, you are right, thanks!

--
Best regards,
Vladimir