Re: [PATCH V2] lightnvm: pblk: fix mapping issue on failed writes

From: Matias BjÃrling
Date: Fri Aug 31 2018 - 10:18:21 EST


On 08/31/2018 11:59 AM, Hans Holmberg wrote:
From: Hans Holmberg <hans.holmberg@xxxxxxxxxxxx>

On 1.2-devices, the mapping-out of remaning sectors in the
failed-write's block can result in an infinite loop,
stalling the write pipeline, fix this.

Fixes: 6a3abf5beef6 ("lightnvm: pblk: rework write error recovery path")

Signed-off-by: Hans Holmberg <hans.holmberg@xxxxxxxxxxxx>
---

Changes in V2:
Moved the helper function pblk_next_ppa_in_blk to lightnvm core
Renamed variable done->last in the helper function


drivers/lightnvm/pblk-write.c | 10 +---------
include/linux/lightnvm.h | 34 ++++++++++++++++++++++++++++++++++
2 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/drivers/lightnvm/pblk-write.c b/drivers/lightnvm/pblk-write.c
index 5e6df65d392c..922506d2d0a6 100644
--- a/drivers/lightnvm/pblk-write.c
+++ b/drivers/lightnvm/pblk-write.c
@@ -125,15 +125,7 @@ static void pblk_map_remaining(struct pblk *pblk, struct ppa_addr *ppa)
if (!test_and_set_bit(paddr, line->invalid_bitmap))
le32_add_cpu(line->vsc, -1);
- if (geo->version == NVM_OCSSD_SPEC_12) {
- map_ppa.ppa++;
- if (map_ppa.g.pg == geo->num_pg)
- done = 1;
- } else {
- map_ppa.m.sec++;
- if (map_ppa.m.sec == geo->clba)
- done = 1;
- }
+ done = nvm_next_ppa_in_blk(geo, &map_ppa);
}
line->w_err_gc->has_write_err = 1;
diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
index 09f65c6c6676..2a6cbfe1d1b4 100644
--- a/include/linux/lightnvm.h
+++ b/include/linux/lightnvm.h
@@ -593,6 +593,40 @@ static inline u32 nvm_ppa64_to_ppa32(struct nvm_dev *dev,
return ppa32;
}
+static inline int nvm_next_ppa_in_blk(struct nvm_geo *geo, struct ppa_addr *ppa)

You can pass nvm_tgt_dev here. Then the two unfoldings in pblk_map_remaining are not needed.

The naming sounds very 1.2ish, how about nvm_get_next_lba_in_chk?

+{
+ int last = 0;
+
+ if (geo->version == NVM_OCSSD_SPEC_12) {
+ int sec = ppa->g.sec;
+
+ sec++;
+ if (sec == geo->ws_min) {
+ int pg = ppa->g.pg;
+
+ sec = 0;
+ pg++;
+ if (pg == geo->num_pg) {
+ int pl = ppa->g.pl;
+
+ pg = 0;
+ pl++;
+ if (pl == geo->num_pln)
+ last = 1;
+
+ ppa->g.pl = pl;
+ }
+ ppa->g.pg = pg;
+ }
+ ppa->g.sec = sec;
+ } else {
+ ppa->m.sec++;
+ if (ppa->m.sec == geo->clba)
+ last = 1;
+ }
+
+ return last;
+}
typedef blk_qc_t (nvm_tgt_make_rq_fn)(struct request_queue *, struct bio *);
typedef sector_t (nvm_tgt_capacity_fn)(void *);