From: Igor Konopko <igor.j.konopko@intel.com>
To: "Matias Bjørling" <mb@lightnvm.io>,
"Javier González" <javier@javigon.com>
Cc: Hans Holmberg <hans.holmberg@cnexlabs.com>, linux-block@vger.kernel.org
Subject: Re: [PATCH 04/18] lightnvm: pblk: OOB recovery for closed chunks fix
Date: Mon, 18 Mar 2019 13:50:42 +0100 [thread overview]
Message-ID: <88dc0cd0-d863-3129-3cae-5d6e133820cf@intel.com> (raw)
In-Reply-To: <5d997ae1-ec1f-6a78-6a93-f15fab542859@lightnvm.io>
On 17.03.2019 20:24, Matias Bjørling wrote:
> On 3/16/19 3:43 PM, Javier González wrote:
>>> On 14 Mar 2019, at 09.04, Igor Konopko <igor.j.konopko@intel.com> wrote:
>>>
>>> In case of OOB recovery, when some of the chunks are in closed state,
>>> we are calculating number of written sectors in line incorrectly,
>>> because we are always counting chunk WP, which for closed chunks
>>> does not longer reflects written sectors in particular chunks. This
>>> patch for such a chunks takes clba field instead.
>>>
>>> Signed-off-by: Igor Konopko <igor.j.konopko@intel.com>
>>> ---
>>> drivers/lightnvm/pblk-recovery.c | 8 +++++++-
>>> 1 file changed, 7 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/lightnvm/pblk-recovery.c
>>> b/drivers/lightnvm/pblk-recovery.c
>>> index 83b467b..bcd3633 100644
>>> --- a/drivers/lightnvm/pblk-recovery.c
>>> +++ b/drivers/lightnvm/pblk-recovery.c
>>> @@ -101,6 +101,8 @@ static void pblk_update_line_wp(struct pblk
>>> *pblk, struct pblk_line *line,
>>>
>>> static u64 pblk_sec_in_open_line(struct pblk *pblk, struct pblk_line
>>> *line)
>>> {
>>> + struct nvm_tgt_dev *dev = pblk->dev;
>>> + struct nvm_geo *geo = &dev->geo;
>>> struct pblk_line_meta *lm = &pblk->lm;
>>> int nr_bb = bitmap_weight(line->blk_bitmap, lm->blk_per_line);
>>> u64 written_secs = 0;
>>> @@ -113,7 +115,11 @@ static u64 pblk_sec_in_open_line(struct pblk
>>> *pblk, struct pblk_line *line)
>>> if (chunk->state & NVM_CHK_ST_OFFLINE)
>>> continue;
>>>
>>> - written_secs += chunk->wp;
>>> + if (chunk->state & NVM_CHK_ST_OPEN)
>>> + written_secs += chunk->wp;
>>> + else if (chunk->state & NVM_CHK_ST_CLOSED)
>>> + written_secs += geo->clba;
>>> +
>>> valid_chunks++;
>>> }
>>>
>>> --
>>> 2.9.5
>>
>> Mmmm. The change is correct, but can you develop on why the WP does not
>> reflect the written sectors in a closed chunk? As I understand it, the
>> WP reflects the last written sector; if it happens to be WP == clba, then
>> the chunk state machine transitions to closed, but the WP remains
>> untouched. It is only when we reset the chunk that the WP comes back to
>> 0. Am I missing something?
>>
>
> I agree with Javier. In OCSSD, the write pointer shall always be valid.
So based on OCSSD 2.0 spec "If WP = SLBA + NLB, the chunk is closed"
(also on "Figure 5: Chunk State Diagram in spec": WP = SLBA + NLB for
closed chunk), my understanding it that the WP is not valid for that
particular use case, since in written_secs we want to obtain NLB field
(relative within chunk, without starting LBA value). So that's why I
used fixed CLBA here, since it WP pointer for closed chunk is absolute
value instead of relative one.
Did I misunderstood sth in the spec?
next prev parent reply other threads:[~2019-03-18 12:50 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-14 16:04 [PATCH 00/18] lightnvm: next set of improvements for 5.2 Igor Konopko
2019-03-14 16:04 ` [PATCH 01/18] lightnvm: pblk: fix warning in pblk_l2p_init() Igor Konopko
2019-03-16 22:29 ` Javier González
2019-03-18 16:25 ` Matias Bjørling
2019-03-14 16:04 ` [PATCH 02/18] lightnvm: pblk: warn when there are opened chunks Igor Konopko
2019-03-16 22:36 ` Javier González
2019-03-17 19:39 ` Matias Bjørling
2019-03-14 16:04 ` [PATCH 03/18] lightnvm: pblk: simplify partial read path Igor Konopko
2019-03-14 21:35 ` Heiner Litz
2019-03-15 9:52 ` Igor Konopko
2019-03-16 22:28 ` Javier González
2019-03-18 12:44 ` Igor Konopko
2019-03-14 16:04 ` [PATCH 04/18] lightnvm: pblk: OOB recovery for closed chunks fix Igor Konopko
2019-03-16 22:43 ` Javier González
2019-03-17 19:24 ` Matias Bjørling
2019-03-18 12:50 ` Igor Konopko [this message]
2019-03-18 19:25 ` Javier González
2019-03-14 16:04 ` [PATCH 05/18] lightnvm: pblk: propagate errors when reading meta Igor Konopko
2019-03-16 22:48 ` Javier González
2019-03-18 11:54 ` Hans Holmberg
2019-03-14 16:04 ` [PATCH 06/18] lightnvm: pblk: recover only written metadata Igor Konopko
2019-03-16 23:46 ` Javier González
2019-03-18 12:54 ` Igor Konopko
2019-03-18 15:04 ` Igor Konopko
2019-03-14 16:04 ` [PATCH 07/18] lightnvm: pblk: wait for inflight IOs in recovery Igor Konopko
2019-03-17 19:33 ` Matias Bjørling
2019-03-18 12:58 ` Igor Konopko
2019-03-14 16:04 ` [PATCH 08/18] lightnvm: pblk: fix spin_unlock order Igor Konopko
2019-03-16 23:49 ` Javier González
2019-03-18 11:55 ` Hans Holmberg
2019-03-14 16:04 ` [PATCH 09/18] lightnvm: pblk: kick writer on write recovery path Igor Konopko
2019-03-16 23:54 ` Javier González
2019-03-18 11:58 ` Hans Holmberg
2019-03-14 16:04 ` [PATCH 10/18] lightnvm: pblk: ensure that emeta is written Igor Konopko
2019-03-17 19:44 ` Matias Bjørling
2019-03-18 13:02 ` Igor Konopko
2019-03-18 18:26 ` Javier González
2019-03-21 13:34 ` Igor Konopko
2019-03-18 7:46 ` Javier González
2019-03-14 16:04 ` [PATCH 11/18] lightnvm: pblk: fix update line wp in OOB recovery Igor Konopko
2019-03-18 6:56 ` Javier González
2019-03-18 13:06 ` Igor Konopko
2019-03-14 16:04 ` [PATCH 12/18] lightnvm: pblk: do not read OOB from emeta region Igor Konopko
2019-03-17 19:56 ` Matias Bjørling
2019-03-18 13:05 ` Igor Konopko
2019-03-14 16:04 ` [PATCH 13/18] lightnvm: pblk: store multiple copies of smeta Igor Konopko
2019-03-18 7:33 ` Javier González
2019-03-18 13:12 ` Igor Konopko
2019-03-14 16:04 ` [PATCH 14/18] lightnvm: pblk: GC error handling Igor Konopko
2019-03-18 7:39 ` Javier González
2019-03-18 12:14 ` Hans Holmberg
2019-03-18 13:22 ` Igor Konopko
2019-03-18 14:14 ` Hans Holmberg
2019-03-14 16:04 ` [PATCH 15/18] lightnvm: pblk: fix in case of lack of lines Igor Konopko
2019-03-18 7:42 ` Javier González
2019-03-18 13:28 ` Igor Konopko
2019-03-18 19:21 ` Javier González
2019-03-21 13:21 ` Igor Konopko
2019-03-22 12:17 ` Hans Holmberg
2019-03-14 16:04 ` [PATCH 16/18] lightnvm: pblk: use nvm_rq_to_ppa_list() Igor Konopko
2019-03-18 7:48 ` Javier González
2019-03-14 16:04 ` [PATCH 17/18] lightnvm: allow to use full device path Igor Konopko
2019-03-18 7:49 ` Javier González
2019-03-18 10:28 ` Hans Holmberg
2019-03-18 13:18 ` Igor Konopko
2019-03-18 14:41 ` Hans Holmberg
2019-03-21 13:18 ` Igor Konopko
2019-03-25 11:40 ` Matias Bjørling
2019-03-14 16:04 ` [PATCH 18/18] lightnvm: track inflight target creations Igor Konopko
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