RE: [GIT PULL 16/20] lightnvm: error handling when whole line is bad

[Konopko, Igor J]

> From: Javier Gonzalez [mailto:jav...@cnexlabs.com]
> This case cannot occur on the only user of the function
> (pblk_recov_l2p()). On the previous check (pblk_line_was_written()), we
> verify the state of the line and the position of the first good chunk. In
> the case of a bad line (less chunks than a given threshold to allow
> emeta), the recovery will not be carried out in the line.
You are right. It looks that during my testing there was some inconsistency 
between chunks state table which is verified inside pblk_line_was_written() and 
blk_bitmap which was read from emeta and is verified in 
pblk_line_smeta_start(). I'm living decision to maintainers whether we should 
keep this sanity check or not - it really just pass gracefully the result from 
pblk_line_smeta_start() where similar sanity check is present.

Igor

RE: [GIT PULL 16/20] lightnvm: error handling when whole line is bad

[Konopko, Igor J]

> From: Javier Gonzalez [mailto:jav...@cnexlabs.com]
> This case cannot occur on the only user of the function
> (pblk_recov_l2p()). On the previous check (pblk_line_was_written()), we
> verify the state of the line and the position of the first good chunk. In
> the case of a bad line (less chunks than a given threshold to allow
> emeta), the recovery will not be carried out in the line.
You are right. It looks that during my testing there was some inconsistency 
between chunks state table which is verified inside pblk_line_was_written() and 
blk_bitmap which was read from emeta and is verified in 
pblk_line_smeta_start(). I'm living decision to maintainers whether we should 
keep this sanity check or not - it really just pass gracefully the result from 
pblk_line_smeta_start() where similar sanity check is present.

Igor

Re: [GIT PULL 16/20] lightnvm: error handling when whole line is bad

[Javier Gonzalez]

> On 28 May 2018, at 10.58, Matias Bjørling  wrote:
> 
> From: Igor Konopko 
> 
> When all the blocks (chunks) in line are marked as bad (offline)
> we shouldn't try to read smeta during init process.
> 
> Currently we are trying to do so by passing -1 as PPA address,
> what causes multiple warnings, that we issuing IOs to out-of-bound
> PPAs.
> 
> Signed-off-by: Igor Konopko 
> Signed-off-by: Marcin Dziegielewski 
> Updated title.
> Signed-off-by: Matias Bjørling 
> ---
> drivers/lightnvm/pblk-core.c | 5 +
> 1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
> index a20b41c355c5..e3e883547198 100644
> --- a/drivers/lightnvm/pblk-core.c
> +++ b/drivers/lightnvm/pblk-core.c
> @@ -868,6 +868,11 @@ int pblk_line_read_smeta(struct pblk *pblk, struct 
> pblk_line *line)
> {
>   u64 bpaddr = pblk_line_smeta_start(pblk, line);
> 
> + if (bpaddr == -1) {
> + /* Whole line is bad - do not try to read smeta. */
> + return 1;
> + }

This case cannot occur on the only user of the function
(pblk_recov_l2p()). On the previous check (pblk_line_was_written()), we
verify the state of the line and the position of the first good chunk. In
the case of a bad line (less chunks than a given threshold to allow
emeta), the recovery will not be carried out in the line.

Javier

Re: [GIT PULL 16/20] lightnvm: error handling when whole line is bad

[Javier Gonzalez]

> On 28 May 2018, at 10.58, Matias Bjørling  wrote:
> 
> From: Igor Konopko 
> 
> When all the blocks (chunks) in line are marked as bad (offline)
> we shouldn't try to read smeta during init process.
> 
> Currently we are trying to do so by passing -1 as PPA address,
> what causes multiple warnings, that we issuing IOs to out-of-bound
> PPAs.
> 
> Signed-off-by: Igor Konopko 
> Signed-off-by: Marcin Dziegielewski 
> Updated title.
> Signed-off-by: Matias Bjørling 
> ---
> drivers/lightnvm/pblk-core.c | 5 +
> 1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
> index a20b41c355c5..e3e883547198 100644
> --- a/drivers/lightnvm/pblk-core.c
> +++ b/drivers/lightnvm/pblk-core.c
> @@ -868,6 +868,11 @@ int pblk_line_read_smeta(struct pblk *pblk, struct 
> pblk_line *line)
> {
>   u64 bpaddr = pblk_line_smeta_start(pblk, line);
> 
> + if (bpaddr == -1) {
> + /* Whole line is bad - do not try to read smeta. */
> + return 1;
> + }

This case cannot occur on the only user of the function
(pblk_recov_l2p()). On the previous check (pblk_line_was_written()), we
verify the state of the line and the position of the first good chunk. In
the case of a bad line (less chunks than a given threshold to allow
emeta), the recovery will not be carried out in the line.

Javier