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

Hans Holmberg
2019-03-04T11:43:58Z

On Mon, Mar 4, 2019 at 10:11 AM Javier González <javier@javigon.com> wrote:
>
> > On 4 Mar 2019, at 10.05, Hans Holmberg <hans.ml.holmberg@owltronix.com> wrote:
> >
> > 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.
> >
>
> Not sure who this is for - better not to top post.
>
> In any case, this is a spec grey zone. I’m ok with cleaning the bits as
> they mean nothing for the reset command. If you feel that strongly about
> this, you can take if with Igor.

Pardon the top-post. It was meant for both you and Igor.

>
> >
> > 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>