Re: [PATCH 04/13] lightnvm: pblk: Rollback in gc read

Igor Konopko
2019-03-04T12:39:39Z

On 04.03.2019 09:44, Hans Holmberg wrote:
> Did you ever see this in the wild?
> The only time pblk_gc_line returns an error is if
> kmalloc(sizeof(struct pblk_line_ws), GFP_KERNEL); fails, and then
> we're in real trouble :)

I never saw this in real life, but still probably good to have a
"proper" handling - since we already have "some" handling.

>
> Reviewed-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
>
> On Mon, Mar 4, 2019 at 8:38 AM Javier González <javier@javigon.com> wrote:
>>
>>> On 27 Feb 2019, at 18.14, Igor Konopko <igor.j.konopko@intel.com> wrote:
>>>
>>> Currently in case of error returned by pblk_gc_line
>>> to pblk_gc_read we leave current line unassigned
>>> from all the lists. This patch fixes that issue.
>>>
>>> Signed-off-by: Igor Konopko <igor.j.konopko@intel.com>
>>> ---
>>> drivers/lightnvm/pblk-gc.c | 7 ++++++-
>>> 1 file changed, 6 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/lightnvm/pblk-gc.c b/drivers/lightnvm/pblk-gc.c
>>> index 511ed0d5333c..533da6ea3e15 100644
>>> --- a/drivers/lightnvm/pblk-gc.c
>>> +++ b/drivers/lightnvm/pblk-gc.c
>>> @@ -361,8 +361,13 @@ static int pblk_gc_read(struct pblk *pblk)
>>>
>>> pblk_gc_kick(pblk);
>>>
>>> - if (pblk_gc_line(pblk, line))
>>> + if (pblk_gc_line(pblk, line)) {
>>> pblk_err(pblk, "failed to GC line %d\n", line->id);
>>> + /* rollback */
>>> + spin_lock(&gc->r_lock);
>>> + list_add_tail(&line->list, &gc->r_list);
>>> + spin_unlock(&gc->r_lock);
>>> + }
>>>
>>> return 0;
>>> }
>>> --
>>> 2.17.1
>>
>> Looks good to me.
>>
>> Reviewed-by: Javier González <javier@javigon.com>