Re: [PATCH 06/13] lightnvm: pblk: Ensure that erase is chunk aligned

Hans Holmberg
2019-03-04T09:05:35Z

I strongly disagree with adding code that would mask implantation errors.

If we want more internal checks, we could add an if statement that
would only be compiled in if CONFIG_NVM_PBLK_DEBUG is enabled.

On Mon, Mar 4, 2019 at 8:48 AM Javier González <javier@javigon.com> wrote:
>
> > On 27 Feb 2019, at 18.14, Igor Konopko <igor.j.konopko@intel.com> wrote:
> >
> > In current pblk implementation of erase command
> > there is a chance tha sector bits are set to some
> > random values for erase PPA. This is unexpected
> > situation, since erase shall be always chunk
> > aligned. This patch fixes that issue
> >
> > Signed-off-by: Igor Konopko <igor.j.konopko@intel.com>
> > ---
> > drivers/lightnvm/pblk-core.c | 1 +
> > drivers/lightnvm/pblk-map.c | 2 ++
> > 2 files changed, 3 insertions(+)
> >
> > diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
> > index a98b2255f963..78b1eea4ab67 100644
> > --- a/drivers/lightnvm/pblk-core.c
> > +++ b/drivers/lightnvm/pblk-core.c
> > @@ -978,6 +978,7 @@ int pblk_line_erase(struct pblk *pblk, struct pblk_line *line)
> >
> > ppa = pblk->luns[bit].bppa; /* set ch and lun */
> > ppa.a.blk = line->id;
> > + ppa.a.reserved = 0;
> >
> > atomic_dec(&line->left_eblks);
> > WARN_ON(test_and_set_bit(bit, line->erase_bitmap));
> > diff --git a/drivers/lightnvm/pblk-map.c b/drivers/lightnvm/pblk-map.c
> > index 79df583ea709..aea46b4ec40f 100644
> > --- a/drivers/lightnvm/pblk-map.c
> > +++ b/drivers/lightnvm/pblk-map.c
> > @@ -161,6 +161,7 @@ int pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
> >
> > *erase_ppa = ppa_list[i];
> > erase_ppa->a.blk = e_line->id;
> > + erase_ppa->a.reserved = 0;
> >
> > spin_unlock(&e_line->lock);
> >
> > @@ -202,6 +203,7 @@ int pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
> > atomic_dec(&e_line->left_eblks);
> > *erase_ppa = pblk->luns[bit].bppa; /* set ch and lun */
> > erase_ppa->a.blk = e_line->id;
> > + erase_ppa->a.reserved = 0;
> > }
> >
> > return 0;
> > --
> > 2.17.1
>
> I’m fine with adding this, but note that there is actually no
> requirement for the erase to be chunk aligned - the only bits that
> should be looked at are group, PU and chunk.
>
> Reviewed-by: Javier González <javier@javigon.com>
>
>