[PATCH 3/7] lightnvm: pblk: stop writes gracefully when running out of lines

From: Hans Holmberg
Date: Mon Nov 05 2018 - 06:42:38 EST

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From: Hans Holmberg <hans.ml.holmberg@xxxxxxxxxxxxx>

From: Hans Holmberg <hans.holmberg@xxxxxxxxxxxx>

If mapping fails (i.e. when running out of lines), handle the error
and stop writing.

Signed-off-by: Hans Holmberg <hans.holmberg@xxxxxxxxxxxx>
---
drivers/lightnvm/pblk-map.c | 47 +++++++++++++++++++++--------------
drivers/lightnvm/pblk-write.c | 30 ++++++++++++++--------
drivers/lightnvm/pblk.h | 4 +--
3 files changed, 51 insertions(+), 30 deletions(-)

diff --git a/drivers/lightnvm/pblk-map.c b/drivers/lightnvm/pblk-map.c
index 6dcbd44e3acb..5a3c28cce8ab 100644
--- a/drivers/lightnvm/pblk-map.c
+++ b/drivers/lightnvm/pblk-map.c
@@ -33,6 +33,9 @@ static int pblk_map_page_data(struct pblk *pblk, unsigned int sentry,
int nr_secs = pblk->min_write_pgs;
int i;

+ if (!line)
+ return -ENOSPC;
+
if (pblk_line_is_full(line)) {
struct pblk_line *prev_line = line;

@@ -42,8 +45,11 @@ static int pblk_map_page_data(struct pblk *pblk, unsigned int sentry,
line = pblk_line_replace_data(pblk);
pblk_line_close_meta(pblk, prev_line);

- if (!line)
- return -EINTR;
+ if (!line) {
+ pblk_pipeline_stop(pblk);
+ return -ENOSPC;
+ }
+
}

emeta = line->emeta;
@@ -84,7 +90,7 @@ static int pblk_map_page_data(struct pblk *pblk, unsigned int sentry,
return 0;
}

-void pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
+int pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
unsigned long *lun_bitmap, unsigned int valid_secs,
unsigned int off)
{
@@ -93,20 +99,22 @@ void pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
unsigned int map_secs;
int min = pblk->min_write_pgs;
int i;
+ int ret;

for (i = off; i < rqd->nr_ppas; i += min) {
map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
- if (pblk_map_page_data(pblk, sentry + i, &ppa_list[i],
- lun_bitmap, &meta_list[i], map_secs)) {
- bio_put(rqd->bio);
- pblk_free_rqd(pblk, rqd, PBLK_WRITE);
- pblk_pipeline_stop(pblk);
- }
+
+ ret = pblk_map_page_data(pblk, sentry + i, &ppa_list[i],
+ lun_bitmap, &meta_list[i], map_secs);
+ if (ret)
+ return ret;
}
+
+ return 0;
}

/* only if erase_ppa is set, acquire erase semaphore */
-void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
+int pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
unsigned int sentry, unsigned long *lun_bitmap,
unsigned int valid_secs, struct ppa_addr *erase_ppa)
{
@@ -119,15 +127,16 @@ void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
unsigned int map_secs;
int min = pblk->min_write_pgs;
int i, erase_lun;
+ int ret;
+

for (i = 0; i < rqd->nr_ppas; i += min) {
map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
- if (pblk_map_page_data(pblk, sentry + i, &ppa_list[i],
- lun_bitmap, &meta_list[i], map_secs)) {
- bio_put(rqd->bio);
- pblk_free_rqd(pblk, rqd, PBLK_WRITE);
- pblk_pipeline_stop(pblk);
- }
+
+ ret = pblk_map_page_data(pblk, sentry + i, &ppa_list[i],
+ lun_bitmap, &meta_list[i], map_secs);
+ if (ret)
+ return ret;

erase_lun = pblk_ppa_to_pos(geo, ppa_list[i]);

@@ -163,7 +172,7 @@ void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
*/
e_line = pblk_line_get_erase(pblk);
if (!e_line)
- return;
+ return -ENOSPC;

/* Erase blocks that are bad in this line but might not be in next */
if (unlikely(pblk_ppa_empty(*erase_ppa)) &&
@@ -174,7 +183,7 @@ void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
bit = find_next_bit(d_line->blk_bitmap,
lm->blk_per_line, bit + 1);
if (bit >= lm->blk_per_line)
- return;
+ return 0;

spin_lock(&e_line->lock);
if (test_bit(bit, e_line->erase_bitmap)) {
@@ -188,4 +197,6 @@ void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
*erase_ppa = pblk->luns[bit].bppa; /* set ch and lun */
erase_ppa->a.blk = e_line->id;
}
+
+ return 0;
}
diff --git a/drivers/lightnvm/pblk-write.c b/drivers/lightnvm/pblk-write.c
index 750f04b8a227..2bf78f81862d 100644
--- a/drivers/lightnvm/pblk-write.c
+++ b/drivers/lightnvm/pblk-write.c
@@ -334,12 +334,13 @@ static int pblk_setup_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
}

if (likely(!e_line || !atomic_read(&e_line->left_eblks)))
- pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, valid, 0);
+ ret = pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap,
+ valid, 0);
else
- pblk_map_erase_rq(pblk, rqd, c_ctx->sentry, lun_bitmap,
+ ret = pblk_map_erase_rq(pblk, rqd, c_ctx->sentry, lun_bitmap,
valid, erase_ppa);

- return 0;
+ return ret;
}

static int pblk_calc_secs_to_sync(struct pblk *pblk, unsigned int secs_avail,
@@ -563,7 +564,7 @@ static void pblk_free_write_rqd(struct pblk *pblk, struct nvm_rq *rqd)
c_ctx->nr_padded);
}

-static int pblk_submit_write(struct pblk *pblk)
+static int pblk_submit_write(struct pblk *pblk, int *secs_left)
{
struct bio *bio;
struct nvm_rq *rqd;
@@ -572,6 +573,8 @@ static int pblk_submit_write(struct pblk *pblk)
unsigned long pos;
unsigned int resubmit;

+ *secs_left = 0;
+
spin_lock(&pblk->resubmit_lock);
resubmit = !list_empty(&pblk->resubmit_list);
spin_unlock(&pblk->resubmit_lock);
@@ -601,17 +604,17 @@ static int pblk_submit_write(struct pblk *pblk)
*/
secs_avail = pblk_rb_read_count(&pblk->rwb);
if (!secs_avail)
- return 1;
+ return 0;

secs_to_flush = pblk_rb_flush_point_count(&pblk->rwb);
if (!secs_to_flush && secs_avail < pblk->min_write_pgs)
- return 1;
+ return 0;

secs_to_sync = pblk_calc_secs_to_sync(pblk, secs_avail,
secs_to_flush);
if (secs_to_sync > pblk->max_write_pgs) {
pblk_err(pblk, "bad buffer sync calculation\n");
- return 1;
+ return 0;
}

secs_to_com = (secs_to_sync > secs_avail) ?
@@ -640,6 +643,7 @@ static int pblk_submit_write(struct pblk *pblk)
atomic_long_add(secs_to_sync, &pblk->sub_writes);
#endif

+ *secs_left = 1;
return 0;

fail_free_bio:
@@ -648,16 +652,22 @@ static int pblk_submit_write(struct pblk *pblk)
bio_put(bio);
pblk_free_rqd(pblk, rqd, PBLK_WRITE);

- return 1;
+ return -EINTR;
}

int pblk_write_ts(void *data)
{
struct pblk *pblk = data;
+ int secs_left;
+ int write_failure = 0;

while (!kthread_should_stop()) {
- if (!pblk_submit_write(pblk))
- continue;
+ if (!write_failure) {
+ write_failure = pblk_submit_write(pblk, &secs_left);
+
+ if (secs_left)
+ continue;
+ }
set_current_state(TASK_INTERRUPTIBLE);
io_schedule();
}
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index 02bb2e98f8a9..f415aae600c8 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -871,10 +871,10 @@ int pblk_write_gc_to_cache(struct pblk *pblk, struct pblk_gc_rq *gc_rq);
/*
* pblk map
*/
-void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
+int pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
unsigned int sentry, unsigned long *lun_bitmap,
unsigned int valid_secs, struct ppa_addr *erase_ppa);
-void pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
+int pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
unsigned long *lun_bitmap, unsigned int valid_secs,
unsigned int off);

--
2.17.1

Next message: Robert Foss: "[PATCH v4 1/4] drm/virtio: add virtio_gpu_alloc_fence()"
Previous message: Robert Foss: "[PATCH v4 4/4] drm/virtio: bump driver version after explicit synchronization addition"
In reply to: Hans Holmberg: "[PATCH 7/7] lightnvm: pblk: remove dead code in pblk_recov_l2p"
Next in thread: Hans Holmberg: "[PATCH 4/7] lightnvm: pblk: set conservative threshold for user writes"
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