Re: [PATCH 08/13] lightnvm: pblk: Set proper read stutus in bio

Javier González
2019-03-04T08:03:59Z

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> On 27 Feb 2019, at 18.14, Igor Konopko <igor.j.konopko@intel.com> wrote:
>
> Currently in case of read errors, bi_status is not
> set properly which leads to returning inproper data
> to higher layer. This patch fix that by setting proper
> status in case of read errors
>
> Patch also removes unnecessary warn_once(), which does
> not make sense in that place, since user bio is not used
> for interation with drive and thus bi_status will not be
> set here.
>
> Signed-off-by: Igor Konopko <igor.j.konopko@intel.com>
> ---
> drivers/lightnvm/pblk-read.c | 11 +++++------
> 1 file changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/lightnvm/pblk-read.c b/drivers/lightnvm/pblk-read.c
> index 3789185144da..39c1d6ccaedb 100644
> --- a/drivers/lightnvm/pblk-read.c
> +++ b/drivers/lightnvm/pblk-read.c
> @@ -175,11 +175,10 @@ static void pblk_read_check_rand(struct pblk *pblk, struct nvm_rq *rqd,
> WARN_ONCE(j != rqd->nr_ppas, "pblk: corrupted random request\n");
> }
>
> -static void pblk_end_user_read(struct bio *bio)
> +static void pblk_end_user_read(struct bio *bio, int error)
> {
> -#ifdef CONFIG_NVM_PBLK_DEBUG
> - WARN_ONCE(bio->bi_status, "pblk: corrupted read bio\n");
> -#endif
> + if (error && error != NVM_RSP_WARN_HIGHECC)
> + bio_io_error(bio);
> bio_endio(bio);
> }
>
> @@ -219,7 +218,7 @@ static void pblk_end_io_read(struct nvm_rq *rqd)
> struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
> struct bio *bio = (struct bio *)r_ctx->private;
>
> - pblk_end_user_read(bio);
> + pblk_end_user_read(bio, rqd->error);
> __pblk_end_io_read(pblk, rqd, true);
> }
>
> @@ -292,7 +291,7 @@ static void pblk_end_partial_read(struct nvm_rq *rqd)
> rqd->bio = NULL;
> rqd->nr_ppas = nr_secs;
>
> - bio_endio(bio);
> + pblk_end_user_read(bio, rqd->error);
> __pblk_end_io_read(pblk, rqd, false);
> }
>
> --
> 2.17.1

This is by design. We do not report the read errors as in any other
block device - this is why we clone the read bio.

If you want to remove the WARN_ONCE, it is fine by me - it helped in the
past to debug the read path as when one read failed we go a storm of
them. Now we have better controller tools to debug this, so if nobody
else wants it there, let’s remove it.

Javier

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