Re: [PATCH BUGFIX] block: add missing group association in bio_split

[Jens Axboe]

On 05/09/2016 08:39 AM, Paolo wrote:
> Il 09/05/2016 16:35, Jeff Moyer ha scritto:
> > Jeff Moyer <jmoyer@xxxxxxxxxx> writes:
> >
> > > Paolo Valente <paolo.valente@xxxxxxxxxx> writes:
> > >
> > > > @@ -1811,6 +1811,11 @@ struct bio *bio_split(struct bio *bio, int
> > > > sectors,
> > > >
> > > >       bio_advance(bio, split->bi_iter.bi_size);
> > > >
> > > > +#ifdef CONFIG_BLK_CGROUP
> > > > +    if (bio->bi_css)
> > > > +        bio_associate_blkcg(split, bio->bi_css);
> > > > +#endif
> > > > +
> > > >       return split;
> > > >   }
> > > >   EXPORT_SYMBOL(bio_split);
> > >
> > > Get rid of the #ifdefery.  This should be just:
> > >
> > > bio_associate_blkcg(split, bio->bi_css);
> >
> > Gah, I see that the bi_css member is only present for CONFIG_BLK_CGROUP.
> > I guess we'll have to live with the ifdef.
>
> We have already tried to remove it, but it seems it would require other
> major changes.

It'd be cleaner to have a

bio_clone_associate_blkcg(split, bio);

or similar, and then hide it in there.

--
Jens Axboe