On Mon, 24 Oct 2022 12:05:50 -0700 Stefan Roesch <shr@xxxxxxxxxxxx> wrote: > This adds the bdi_set_strict_limit function to be able to set/unset the > BDI_CAP_STRICTLIMIT flag. > > ... > > --- a/mm/page-writeback.c > +++ b/mm/page-writeback.c > @@ -698,6 +698,22 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned max_ratio) > } > EXPORT_SYMBOL(bdi_set_max_ratio); > > +int bdi_set_strict_limit(struct backing_dev_info *bdi, unsigned int strict_limit) > +{ > + if (strict_limit > 1) > + return -EINVAL; > + > + spin_lock_bh(&bdi_lock); > + if (strict_limit) > + bdi->capabilities |= BDI_CAP_STRICTLIMIT; > + else > + bdi->capabilities &= ~BDI_CAP_STRICTLIMIT; > + spin_unlock_bh(&bdi_lock); > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(bdi_set_strict_limit); I don't believe the export is needed?