Re: [PATCH 02/13] lightnvm: pblk: Gracefully handle GC data malloc fail

Hans Holmberg
2019-03-01T12:51:14Z

On Thu, Feb 28, 2019 at 6:09 PM Javier González <javier@javigon.com> wrote:
>
>
>
> > On 27 Feb 2019, at 12.14, Igor Konopko <igor.j.konopko@intel.com> wrote:
> >
> > Currently when we fail on gc rq data allocation
> > we simply skip the data which we wanted to move
> > and finally move the line to free state and lose
> > that data due to that. This patch move the data
> > allocation to some earlier phase of GC, where we
> > can still fail gracefully by moving line back
> > to closed state.
> >
> > Signed-off-by: Igor Konopko <igor.j.konopko@intel.com>
> > ---
> > drivers/lightnvm/pblk-gc.c | 19 +++++++++----------
> > 1 file changed, 9 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/lightnvm/pblk-gc.c b/drivers/lightnvm/pblk-gc.c
> > index 3feadfd9418d..31fc1339faa8 100644
> > --- a/drivers/lightnvm/pblk-gc.c
> > +++ b/drivers/lightnvm/pblk-gc.c
> > @@ -84,8 +84,6 @@ static void pblk_gc_line_ws(struct work_struct *work)
> > struct pblk_line_ws *gc_rq_ws = container_of(work,
> > struct pblk_line_ws, ws);
> > struct pblk *pblk = gc_rq_ws->pblk;
> > - struct nvm_tgt_dev *dev = pblk->dev;
> > - struct nvm_geo *geo = &dev->geo;
> > struct pblk_gc *gc = &pblk->gc;
> > struct pblk_line *line = gc_rq_ws->line;
> > struct pblk_gc_rq *gc_rq = gc_rq_ws->priv;
> > @@ -93,13 +91,6 @@ static void pblk_gc_line_ws(struct work_struct *work)
> >
> > up(&gc->gc_sem);
> >
> > - gc_rq->data = vmalloc(array_size(gc_rq->nr_secs, geo->csecs));
> > - if (!gc_rq->data) {
> > - pblk_err(pblk, "could not GC line:%d (%d/%d)\n",
> > - line->id, *line->vsc, gc_rq->nr_secs);
> > - goto out;
> > - }
> > -
> > /* Read from GC victim block */
> > ret = pblk_submit_read_gc(pblk, gc_rq);
> > if (ret) {
> > @@ -189,6 +180,8 @@ static void pblk_gc_line_prepare_ws(struct work_struct *work)
> > struct pblk_line *line = line_ws->line;
> > struct pblk_line_mgmt *l_mg = &pblk->l_mg;
> > struct pblk_line_meta *lm = &pblk->lm;
> > + struct nvm_tgt_dev *dev = pblk->dev;
> > + struct nvm_geo *geo = &dev->geo;
> > struct pblk_gc *gc = &pblk->gc;
> > struct pblk_line_ws *gc_rq_ws;
> > struct pblk_gc_rq *gc_rq;
> > @@ -247,9 +240,13 @@ static void pblk_gc_line_prepare_ws(struct work_struct *work)
> > gc_rq->nr_secs = nr_secs;
> > gc_rq->line = line;
> >
> > + gc_rq->data = vmalloc(gc_rq->nr_secs * geo->csecs);

Why not use array_size to do the size calculation as before? It checks
for overflows.
Apart from this, the patch looks good to me.

> > + if (!gc_rq->data)
> > + goto fail_free_gc_rq;
> > +
> > gc_rq_ws = kmalloc(sizeof(struct pblk_line_ws), GFP_KERNEL);
> > if (!gc_rq_ws)
> > - goto fail_free_gc_rq;
> > + goto fail_free_gc_data;
> >
> > gc_rq_ws->pblk = pblk;
> > gc_rq_ws->line = line;
> > @@ -281,6 +278,8 @@ static void pblk_gc_line_prepare_ws(struct work_struct *work)
> >
> > return;
> >
> > +fail_free_gc_data:
> > + vfree(gc_rq->data);
> > fail_free_gc_rq:
> > kfree(gc_rq);
> > fail_free_lba_list:
> > --
> > 2.17.1
>
> Looks good to me.
>
> Reviewed-by: Javier González <javier@javigon.com>