Re: [PATCH 1/9] lightnvm: pblk: prevent gc kicks when gc is not operational

From: Javier GonzÃlez
Date: Tue Oct 03 2017 - 06:27:49 EST


> On 3 Oct 2017, at 12.05, Hans Holmberg <hans.ml.holmberg@xxxxxxxxxxxxx> wrote:
>
> From: Hans Holmberg <hans.holmberg@xxxxxxxxxxxx>
>
> GC can be kicked after it has been shut down when closing the last
> line during exit, resulting in accesses to freed structures.
>
> Make sure that GC is not triggered while it is not operational.
> Also make sure that GC won't be re-activated during exit when
> running on another processor by using timer_del_sync.
>
> Signed-off-by: Hans Holmberg <hans.holmberg@xxxxxxxxxxxx>
> ---
> drivers/lightnvm/pblk-gc.c | 9 +++++----
> drivers/lightnvm/pblk-init.c | 1 +
> 2 files changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/lightnvm/pblk-gc.c b/drivers/lightnvm/pblk-gc.c
> index 7b103bc..81efac1 100644
> --- a/drivers/lightnvm/pblk-gc.c
> +++ b/drivers/lightnvm/pblk-gc.c
> @@ -478,10 +478,10 @@ void pblk_gc_should_start(struct pblk *pblk)
> {
> struct pblk_gc *gc = &pblk->gc;
>
> - if (gc->gc_enabled && !gc->gc_active)
> + if (gc->gc_enabled && !gc->gc_active) {
> pblk_gc_start(pblk);
> -
> - pblk_gc_kick(pblk);
> + pblk_gc_kick(pblk);
> + }
> }
>
> /*
> @@ -620,7 +620,8 @@ void pblk_gc_exit(struct pblk *pblk)
> flush_workqueue(gc->gc_reader_wq);
> flush_workqueue(gc->gc_line_reader_wq);
>
> - del_timer(&gc->gc_timer);
> + gc->gc_enabled = 0;
> + del_timer_sync(&gc->gc_timer);
> pblk_gc_stop(pblk, 1);
>
> if (gc->gc_ts)
> diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
> index 0163914..ec7974b 100644
> --- a/drivers/lightnvm/pblk-init.c
> +++ b/drivers/lightnvm/pblk-init.c
> @@ -928,6 +928,7 @@ static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
> pblk->dev = dev;
> pblk->disk = tdisk;
> pblk->state = PBLK_STATE_RUNNING;
> + pblk->gc.gc_enabled = 0;
>
> spin_lock_init(&pblk->trans_lock);
> spin_lock_init(&pblk->lock);
> --
> 2.7.4

LGTM.

Reviewed-by: Javier GonzÃlez <javier@xxxxxxxxxxxx>

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