On Tue, Jan 29, 2019 at 11:10 PM Zhoujie Wu <zjwu@xxxxxxxxxxx> wrote:
>
> Sorry that my Linux email client has configuration issue and can't reply email. Used my outlook to reply as plain text and hope that I won't corrupt the format.
> Tested on my board and it works well. Since this is a good fix, I think you don't need to do it based on my previous v3 patch and can directly apply yours:)
>
> Tested-by: Zhoujie Wu <zjwu@xxxxxxxxxxx>
Thanks Zhoujie!
I'll squash the two patches into a V2, carrying over the tested-by and
credit you as Reported-by if you don't mind.
>
>
> -----Original Message-----
> From: hans@xxxxxxxxxxxxx <hans@xxxxxxxxxxxxx>
> Sent: Tuesday, January 29, 2019 12:48 AM
> To: Matias Bjorling <mb@xxxxxxxxxxx>
> Cc: javier@xxxxxxxxxxx; Zhoujie Wu <zjwu@xxxxxxxxxxx>; linux-block@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Hans Holmberg <hans.holmberg@xxxxxxxxxxxx>
> Subject: [EXT] [PATCH] lightnvm: pblk: extend line wp balance check
>
> External Email
>
> ----------------------------------------------------------------------
> From: Hans Holmberg <hans.holmberg@xxxxxxxxxxxx>
>
> pblk stripes writes of minimal write size across all non-offline chunks in a line, which means that the maximum write pointer delta should not exceed the minimal write size. Extend the line write pointer balance check to cover this case.
>
> Signed-off-by: Hans Holmberg <hans.holmberg@xxxxxxxxxxxx>
> ---
>
> This patch applies on top of Zhoujie's V3 of
> "lightnvm: pblk: ignore bad block wp for pblk_line_wp_is_unbalanced
>
> drivers/lightnvm/pblk-recovery.c | 60 ++++++++++++++++++++------------
> 1 file changed, 37 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/lightnvm/pblk-recovery.c b/drivers/lightnvm/pblk-recovery.c
> index 02d466e6925e..d86f580036d3 100644
> --- a/drivers/lightnvm/pblk-recovery.c
> +++ b/drivers/lightnvm/pblk-recovery.c
> @@ -302,41 +302,55 @@ static int pblk_pad_distance(struct pblk *pblk, struct pblk_line *line)
> return (distance > line->left_msecs) ? line->left_msecs : distance; }
>
> -static int pblk_line_wp_is_unbalanced(struct pblk *pblk,
> - struct pblk_line *line)
> +/* Return a chunk belonging to a line by stripe(write order) index */
> +static struct nvm_chk_meta *pblk_get_stripe_chunk(struct pblk *pblk,
> + struct pblk_line *line,
> + int index)
> {
> struct nvm_tgt_dev *dev = pblk->dev;
> struct nvm_geo *geo = &dev->geo;
> - struct pblk_line_meta *lm = &pblk->lm;
> struct pblk_lun *rlun;
> - struct nvm_chk_meta *chunk;
> struct ppa_addr ppa;
> - u64 line_wp;
> - int pos, i, bit;
> + int pos;
>
> - bit = find_first_zero_bit(line->blk_bitmap, lm->blk_per_line);
> - if (bit >= lm->blk_per_line)
> - return 0;
> - rlun = &pblk->luns[bit];
> + rlun = &pblk->luns[index];
> ppa = rlun->bppa;
> pos = pblk_ppa_to_pos(geo, ppa);
> - chunk = &line->chks[pos];
>
> - line_wp = chunk->wp;
> + return &line->chks[pos];
> +}
>
> - for (i = bit + 1; i < lm->blk_per_line; i++) {
> - rlun = &pblk->luns[i];
> - ppa = rlun->bppa;
> - pos = pblk_ppa_to_pos(geo, ppa);
> - chunk = &line->chks[pos];
> +static int pblk_line_wps_are_unbalanced(struct pblk *pblk,
> + struct pblk_line *line)
> +{
> + struct pblk_line_meta *lm = &pblk->lm;
> + int blk_in_line = lm->blk_per_line;
> + struct nvm_chk_meta *chunk;
> + u64 max_wp, min_wp;
> + int i;
>
> - if (chunk->state & NVM_CHK_ST_OFFLINE)
> - continue;
> + i = find_first_zero_bit(line->blk_bitmap, blk_in_line);
> +
> + /* If there is one or zero good chunks in the line,
> + * the write pointers can't be unbalanced.
> + */
> + if (i >= (blk_in_line - 1))
> + return 0;
>
> - if (chunk->wp > line_wp)
> + chunk = pblk_get_stripe_chunk(pblk, line, i);
> + max_wp = chunk->wp;
> + if (max_wp > pblk->max_write_pgs)
> + min_wp = max_wp - pblk->max_write_pgs;
> + else
> + min_wp = 0;
> +
> + i = find_next_zero_bit(line->blk_bitmap, blk_in_line, i + 1);
> + while (i < blk_in_line) {
> + chunk = pblk_get_stripe_chunk(pblk, line, i);
> + if (chunk->wp > max_wp || chunk->wp < min_wp)
> return 1;
> - else if (chunk->wp < line_wp)
> - line_wp = chunk->wp;
> +
> + i = find_next_zero_bit(line->blk_bitmap, blk_in_line, i + 1);
> }
>
> return 0;
> @@ -362,7 +376,7 @@ static int pblk_recov_scan_oob(struct pblk *pblk, struct pblk_line *line,
> int ret;
> u64 left_ppas = pblk_sec_in_open_line(pblk, line) - lm->smeta_sec;
>
> - if (pblk_line_wp_is_unbalanced(pblk, line))
> + if (pblk_line_wps_are_unbalanced(pblk, line))
> pblk_warn(pblk, "recovering unbalanced line (%d)\n", line->id);
>
> ppa_list = p.ppa_list;
> --
> 2.17.1
>
