[PATCH 00/20] LightNVM: pblk patches for 4.13

[PATCH 00/20] LightNVM: pblk patches for 4.13

[Javier González]

Hi Matias,

Here you have the pblk patchset for this window.

Apart from small fixes for LightNVM core and pblk, there are three
relevant changes:

 - Metadata for each line is no longer issued on a separate workqueue,
   but instead, all I/Os are scheduled on the write thread. This allows
   to have more control over LUN collisions. The result is that we can
   use the full bandwidth of the device for user data. In the 4.12 pblk,
   we use ~25% of the bandwidth for metadata.

 - The rate-limiter and GC have been tuned to keep the GC writer busy.
   Also, capacity per line is guaranteed for GC I/O as we reach
   capacity.

 - We have now a FTL state machine. This allows to fail gracefully to
   user space in case of irrecoverable errors. This state machine will
   be the base for the pblk's FTL log.

The patches apply into your for-4.13/core. You can also find them in:

  https://github.com/OpenChannelSSD/linux.git pblk.for-4.13

Thanks,
Javier

Javier González (20):
  lightnvm: re-convert ppa format on I/O failure
  lightnvm: propagate right error code to target
  lightnvm: pblk: spare double cpu_to_le64 calc.
  lightnvm: pblk: add debug stat for read cache hits
  lightnvm: pblk: expose max sec per write on sysfs
  lightnvm: pblk: generalize erase path
  lightnvm: pblk: rename read request pool
  lightnvm: pblk: sched. metadata on write thread
  lightnvm: pblk: delete redundant debug line stat
  lightnvm: pblk: delete redundant buffer pointer
  lightnvm: pblk: issue multiplane reads if possible
  lightnvm: pblk: simplify meta. memory allocation
  lightnvm: pblk: decouple bad block from line alloc
  lightnvm: pblk: choose optimal victim GC line
  lightnvm: pblk: set metadata list for all I/Os
  lightnvm: pblk: cleanup unnecessary code
  lightnvm: pblk: add lock assertions on helpers
  lightnvm: pblk: redesign GC algorithm
  lightnvm: pblk: set mempool and workqueue params.
  lightnvm: pblk: fail gracefully on irrec. error

 drivers/lightnvm/core.c          |   8 +-
 drivers/lightnvm/pblk-cache.c    |   8 +-
 drivers/lightnvm/pblk-core.c     | 606 ++++++++++++++++++++++++++-------------
 drivers/lightnvm/pblk-gc.c       | 488 ++++++++++++++++++-------------
 drivers/lightnvm/pblk-init.c     | 358 ++++++++++++++---------
 drivers/lightnvm/pblk-map.c      |  73 +++--
 drivers/lightnvm/pblk-rb.c       |  79 +++--
 drivers/lightnvm/pblk-read.c     |  82 +++---
 drivers/lightnvm/pblk-recovery.c | 130 +++++----
 drivers/lightnvm/pblk-rl.c       |  88 ++++--
 drivers/lightnvm/pblk-sysfs.c    | 114 ++++----
 drivers/lightnvm/pblk-write.c    | 350 +++++++++++++++++-----
 drivers/lightnvm/pblk.h          | 275 +++++++++++++-----
 drivers/nvme/host/lightnvm.c     |   2 +-
 14 files changed, 1763 insertions(+), 898 deletions(-)

-- 
2.7.4

[PATCH 01/20] lightnvm: re-convert ppa format on I/O failure

[Javier González]

In case of a failure when submitting a request, convert the ppa_list
addresses to the target format so that it can interpret ppas for
recovery

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/core.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index 440deb54031a..9ff348f69370 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -641,6 +641,7 @@ EXPORT_SYMBOL(nvm_max_phys_sects);
 int nvm_submit_io(struct nvm_tgt_dev *tgt_dev, struct nvm_rq *rqd)
 {
 	struct nvm_dev *dev = tgt_dev->parent;
+	int ret;
 
 	if (!dev->ops->submit_io)
 		return -ENODEV;
@@ -648,7 +649,12 @@ int nvm_submit_io(struct nvm_tgt_dev *tgt_dev, struct nvm_rq *rqd)
 	nvm_rq_tgt_to_dev(tgt_dev, rqd);
 
 	rqd->dev = tgt_dev;
-	return dev->ops->submit_io(dev, rqd);
+
+	/* In case of error, fail with right address format */
+	ret = dev->ops->submit_io(dev, rqd);
+	if (ret)
+		nvm_rq_dev_to_tgt(tgt_dev, rqd);
+	return ret;
 }
 EXPORT_SYMBOL(nvm_submit_io);
 
-- 
2.7.4

[PATCH 02/20] lightnvm: propagate right error code to target

[Javier González]

If nvme_alloc_request fails, propagate the right error, instead of
assuming ENOMEM.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/nvme/host/lightnvm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index 2d7a2889866f..334943189dd1 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -509,7 +509,7 @@ static int nvme_nvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
 	rq = nvme_alloc_request(q, (struct nvme_command *)cmd, 0, NVME_QID_ANY);
 	if (IS_ERR(rq)) {
 		kfree(cmd);
-		return -ENOMEM;
+		return PTR_ERR(rq);
 	}
 	rq->cmd_flags &= ~REQ_FAILFAST_DRIVER;
 
-- 
2.7.4

[PATCH 03/20] lightnvm: pblk: spare double cpu_to_le64 calc.

[Javier González]

Spare a double calculation on the fast write path.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/pblk-map.c      | 5 +++--
 drivers/lightnvm/pblk-recovery.c | 4 ++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/lightnvm/pblk-map.c b/drivers/lightnvm/pblk-map.c
index 17c16955284d..18291c238930 100644
--- a/drivers/lightnvm/pblk-map.c
+++ b/drivers/lightnvm/pblk-map.c
@@ -53,8 +53,9 @@ static void pblk_map_page_data(struct pblk *pblk, unsigned int sentry,
 			lba_list[paddr] = cpu_to_le64(w_ctx->lba);
 			le64_add_cpu(&line->emeta->nr_valid_lbas, 1);
 		} else {
-			meta_list[i].lba = cpu_to_le64(ADDR_EMPTY);
-			lba_list[paddr] = cpu_to_le64(ADDR_EMPTY);
+			u64 addr_empty = cpu_to_le64(ADDR_EMPTY);
+
+			lba_list[paddr] = meta_list[i].lba = addr_empty;
 			pblk_map_pad_invalidate(pblk, line, paddr);
 		}
 	}
diff --git a/drivers/lightnvm/pblk-recovery.c b/drivers/lightnvm/pblk-recovery.c
index f8f85087cd3c..82787006b865 100644
--- a/drivers/lightnvm/pblk-recovery.c
+++ b/drivers/lightnvm/pblk-recovery.c
@@ -390,12 +390,12 @@ static int pblk_recov_pad_oob(struct pblk *pblk, struct pblk_line *line,
 
 		for (j = 0; j < pblk->min_write_pgs; j++, i++, w_ptr++) {
 			struct ppa_addr dev_ppa;
+			u64 addr_empty = cpu_to_le64(ADDR_EMPTY);
 
 			dev_ppa = addr_to_gen_ppa(pblk, w_ptr, line->id);
 
 			pblk_map_invalidate(pblk, dev_ppa);
-			meta_list[i].lba = cpu_to_le64(ADDR_EMPTY);
-			lba_list[w_ptr] = cpu_to_le64(ADDR_EMPTY);
+			lba_list[w_ptr] = meta_list[i].lba = addr_empty;
 			rqd->ppa_list[i] = dev_ppa;
 		}
 	}
-- 
2.7.4

[PATCH 04/20] lightnvm: pblk: add debug stat for read cache hits

[Javier González]

Add a new debug counter to measure cache hits on the read path

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/pblk-init.c  | 1 +
 drivers/lightnvm/pblk-read.c  | 6 ++++++
 drivers/lightnvm/pblk-sysfs.c | 3 ++-
 drivers/lightnvm/pblk.h       | 1 +
 4 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
index ae8cd6d5af8b..3ec3deff709f 100644
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -838,6 +838,7 @@ static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
 	atomic_long_set(&pblk->sync_writes, 0);
 	atomic_long_set(&pblk->compl_writes, 0);
 	atomic_long_set(&pblk->inflight_reads, 0);
+	atomic_long_set(&pblk->cache_reads, 0);
 	atomic_long_set(&pblk->sync_reads, 0);
 	atomic_long_set(&pblk->recov_writes, 0);
 	atomic_long_set(&pblk->recov_writes, 0);
diff --git a/drivers/lightnvm/pblk-read.c b/drivers/lightnvm/pblk-read.c
index 762c0b73cb67..91307297e444 100644
--- a/drivers/lightnvm/pblk-read.c
+++ b/drivers/lightnvm/pblk-read.c
@@ -76,6 +76,9 @@ static void pblk_read_ppalist_rq(struct pblk *pblk, struct nvm_rq *rqd,
 			}
 			WARN_ON(test_and_set_bit(i, read_bitmap));
 			advanced_bio = 1;
+#ifdef CONFIG_NVM_DEBUG
+			atomic_long_inc(&pblk->cache_reads);
+#endif
 		} else {
 			/* Read from media non-cached sectors */
 			rqd->ppa_list[j++] = p;
@@ -280,6 +283,9 @@ static void pblk_read_rq(struct pblk *pblk, struct nvm_rq *rqd,
 			goto retry;
 		}
 		WARN_ON(test_and_set_bit(0, read_bitmap));
+#ifdef CONFIG_NVM_DEBUG
+			atomic_long_inc(&pblk->cache_reads);
+#endif
 	} else {
 		rqd->ppa_addr = ppa;
 	}
diff --git a/drivers/lightnvm/pblk-sysfs.c b/drivers/lightnvm/pblk-sysfs.c
index f0af1d1ceeff..3c1a586c09a2 100644
--- a/drivers/lightnvm/pblk-sysfs.c
+++ b/drivers/lightnvm/pblk-sysfs.c
@@ -294,7 +294,7 @@ static ssize_t pblk_sysfs_lines_info(struct pblk *pblk, char *page)
 static ssize_t pblk_sysfs_stats_debug(struct pblk *pblk, char *page)
 {
 	return snprintf(page, PAGE_SIZE,
-		"%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\n",
+		"%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\n",
 			atomic_long_read(&pblk->inflight_writes),
 			atomic_long_read(&pblk->inflight_reads),
 			atomic_long_read(&pblk->req_writes),
@@ -307,6 +307,7 @@ static ssize_t pblk_sysfs_stats_debug(struct pblk *pblk, char *page)
 			atomic_long_read(&pblk->recov_writes),
 			atomic_long_read(&pblk->recov_gc_writes),
 			atomic_long_read(&pblk->recov_gc_reads),
+			atomic_long_read(&pblk->cache_reads),
 			atomic_long_read(&pblk->sync_reads));
 }
 #endif
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index 99f3186b5288..70b65d308dea 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -513,6 +513,7 @@ struct pblk {
 	atomic_long_t sync_writes;	/* Sectors synced to media */
 	atomic_long_t compl_writes;	/* Sectors completed in write bio */
 	atomic_long_t inflight_reads;	/* Inflight sector read requests */
+	atomic_long_t cache_reads;	/* Read requests that hit the cache */
 	atomic_long_t sync_reads;	/* Completed sector read requests */
 	atomic_long_t recov_writes;	/* Sectors submitted from recovery */
 	atomic_long_t recov_gc_writes;	/* Sectors submitted from write GC */
-- 
2.7.4

[PATCH 05/20] lightnvm: pblk: expose max sec per write on sysfs

[Javier González]

Allow to configure the number of maximum sectors per write command
through sysfs. This makes it easier to tune write command sizes for
different controller configurations.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/pblk-core.c  |  7 ++++++-
 drivers/lightnvm/pblk-init.c  |  2 ++
 drivers/lightnvm/pblk-sysfs.c | 38 ++++++++++++++++++++++++++++++++++++++
 drivers/lightnvm/pblk.h       |  2 ++
 4 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index 4e0de995cd90..567ed5aa5a0f 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -397,6 +397,11 @@ void pblk_log_read_err(struct pblk *pblk, struct nvm_rq *rqd)
 #endif
 }
 
+void pblk_set_sec_per_write(struct pblk *pblk, int sec_per_write)
+{
+	pblk->sec_per_write = sec_per_write;
+}
+
 int pblk_submit_io(struct pblk *pblk, struct nvm_rq *rqd)
 {
 	struct nvm_tgt_dev *dev = pblk->dev;
@@ -478,7 +483,7 @@ struct bio *pblk_bio_map_addr(struct pblk *pblk, void *data,
 int pblk_calc_secs(struct pblk *pblk, unsigned long secs_avail,
 		   unsigned long secs_to_flush)
 {
-	int max = pblk->max_write_pgs;
+	int max = pblk->sec_per_write;
 	int min = pblk->min_write_pgs;
 	int secs_to_sync = 0;
 
diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
index 3ec3deff709f..6dd85860e419 100644
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -249,6 +249,8 @@ static int pblk_core_init(struct pblk *pblk)
 	pblk->pgs_in_buffer = NVM_MEM_PAGE_WRITE * geo->sec_per_pg *
 						geo->nr_planes * geo->nr_luns;
 
+	pblk_set_sec_per_write(pblk, pblk->min_write_pgs);
+
 	if (pblk->max_write_pgs > PBLK_MAX_REQ_ADDRS) {
 		pr_err("pblk: cannot support device max_phys_sect\n");
 		return -EINVAL;
diff --git a/drivers/lightnvm/pblk-sysfs.c b/drivers/lightnvm/pblk-sysfs.c
index 3c1a586c09a2..bf8fc6699299 100644
--- a/drivers/lightnvm/pblk-sysfs.c
+++ b/drivers/lightnvm/pblk-sysfs.c
@@ -290,6 +290,11 @@ static ssize_t pblk_sysfs_lines_info(struct pblk *pblk, char *page)
 	return sz;
 }
 
+static ssize_t pblk_sysfs_get_sec_per_write(struct pblk *pblk, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%d\n", pblk->sec_per_write);
+}
+
 #ifdef CONFIG_NVM_DEBUG
 static ssize_t pblk_sysfs_stats_debug(struct pblk *pblk, char *page)
 {
@@ -354,6 +359,29 @@ static ssize_t pblk_sysfs_gc_force(struct pblk *pblk, const char *page,
 	return len;
 }
 
+static ssize_t pblk_sysfs_set_sec_per_write(struct pblk *pblk,
+					     const char *page, size_t len)
+{
+	size_t c_len;
+	int sec_per_write;
+
+	c_len = strcspn(page, "\n");
+	if (c_len >= len)
+		return -EINVAL;
+
+	if (kstrtouint(page, 0, &sec_per_write))
+		return -EINVAL;
+
+	if (sec_per_write < pblk->min_write_pgs
+				|| sec_per_write > pblk->max_write_pgs
+				|| sec_per_write % pblk->min_write_pgs != 0)
+		return -EINVAL;
+
+	pblk_set_sec_per_write(pblk, sec_per_write);
+
+	return len;
+}
+
 static struct attribute sys_write_luns = {
 	.name = "write_luns",
 	.mode = 0444,
@@ -399,6 +427,11 @@ static struct attribute sys_gc_force = {
 	.mode = 0200,
 };
 
+static struct attribute sys_max_sec_per_write = {
+	.name = "max_sec_per_write",
+	.mode = 0644,
+};
+
 static struct attribute sys_gc_rl_max = {
 	.name = "gc_rl_max",
 	.mode = 0200,
@@ -417,6 +450,7 @@ static struct attribute *pblk_attrs[] = {
 	&sys_errors_attr,
 	&sys_gc_state,
 	&sys_gc_force,
+	&sys_max_sec_per_write,
 	&sys_gc_rl_max,
 	&sys_rb_attr,
 	&sys_stats_ppaf_attr,
@@ -449,6 +483,8 @@ static ssize_t pblk_sysfs_show(struct kobject *kobj, struct attribute *attr,
 		return pblk_sysfs_lines(pblk, buf);
 	else if (strcmp(attr->name, "lines_info") == 0)
 		return pblk_sysfs_lines_info(pblk, buf);
+	else if (strcmp(attr->name, "max_sec_per_write") == 0)
+		return pblk_sysfs_get_sec_per_write(pblk, buf);
 #ifdef CONFIG_NVM_DEBUG
 	else if (strcmp(attr->name, "stats") == 0)
 		return pblk_sysfs_stats_debug(pblk, buf);
@@ -465,6 +501,8 @@ static ssize_t pblk_sysfs_store(struct kobject *kobj, struct attribute *attr,
 		return pblk_sysfs_rate_store(pblk, buf, len);
 	else if (strcmp(attr->name, "gc_force") == 0)
 		return pblk_sysfs_gc_force(pblk, buf, len);
+	else if (strcmp(attr->name, "max_sec_per_write") == 0)
+		return pblk_sysfs_set_sec_per_write(pblk, buf, len);
 
 	return 0;
 }
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index 70b65d308dea..c18fda522b34 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -499,6 +499,7 @@ struct pblk {
 	/* pblk provisioning values. Used by rate limiter */
 	struct pblk_rl rl;
 
+	int sec_per_write;
 	struct semaphore erase_sem;
 
 	unsigned char instance_uuid[16];
@@ -613,6 +614,7 @@ ssize_t pblk_rb_sysfs(struct pblk_rb *rb, char *buf);
  * pblk core
  */
 struct nvm_rq *pblk_alloc_rqd(struct pblk *pblk, int rw);
+void pblk_set_sec_per_write(struct pblk *pblk, int sec_per_write);
 int pblk_setup_w_rec_rq(struct pblk *pblk, struct nvm_rq *rqd,
 			struct pblk_c_ctx *c_ctx);
 void pblk_free_rqd(struct pblk *pblk, struct nvm_rq *rqd, int rw);
-- 
2.7.4

[PATCH 06/20] lightnvm: pblk: generalize erase path

[Javier González]

Erase I/Os are scheduled with the following goals in mind: (i) minimize
LUNs collisions with write I/Os, and (ii) even out the price of erasing
on every write, instead of putting all the burden on when garbage
collection runs. This works well on the current design, but is specific
to the default mapping algorithm.

This patch generalizes the erase path so that other mapping algorithms
can select an arbitrary line to be erased instead. It also gets rid of
the erase semaphore since it creates jittering for user writes.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/pblk-core.c  |   4 +-
 drivers/lightnvm/pblk-init.c  |   9 ++--
 drivers/lightnvm/pblk-map.c   |  38 +++++++++++----
 drivers/lightnvm/pblk-rb.c    |  33 +++++++------
 drivers/lightnvm/pblk-write.c | 109 +++++++++++++++++++++++-------------------
 drivers/lightnvm/pblk.h       |  11 ++---
 6 files changed, 115 insertions(+), 89 deletions(-)

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index 567ed5aa5a0f..a1125547e638 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -61,7 +61,6 @@ static void pblk_end_io_erase(struct nvm_rq *rqd)
 {
 	struct pblk *pblk = rqd->private;
 
-	up(&pblk->erase_sem);
 	__pblk_end_io_erase(pblk, rqd);
 	mempool_free(rqd, pblk->r_rq_pool);
 }
@@ -1373,7 +1372,8 @@ struct pblk_line *pblk_line_get_data(struct pblk *pblk)
 	return pblk->l_mg.data_line;
 }
 
-struct pblk_line *pblk_line_get_data_next(struct pblk *pblk)
+/* For now, always erase next line */
+struct pblk_line *pblk_line_get_erase(struct pblk *pblk)
 {
 	return pblk->l_mg.data_next;
 }
diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
index 6dd85860e419..5ea610957fb3 100644
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -544,7 +544,7 @@ static int pblk_lines_init(struct pblk *pblk)
 	struct pblk_line_meta *lm = &pblk->lm;
 	struct pblk_line *line;
 	unsigned int smeta_len, emeta_len;
-	long nr_bad_blks, nr_meta_blks, nr_free_blks;
+	long nr_bad_blks, nr_free_blks;
 	int bb_distance;
 	int i;
 	int ret;
@@ -590,9 +590,8 @@ static int pblk_lines_init(struct pblk *pblk)
 	}
 	lm->emeta_bb = geo->nr_luns - i;
 
-	nr_meta_blks = (lm->smeta_sec + lm->emeta_sec +
-				(geo->sec_per_blk / 2)) / geo->sec_per_blk;
-	lm->min_blk_line = nr_meta_blks + 1;
+	lm->min_blk_line = 1 + DIV_ROUND_UP(lm->smeta_sec + lm->emeta_sec,
+							geo->sec_per_blk);
 
 	l_mg->nr_lines = geo->blks_per_lun;
 	l_mg->log_line = l_mg->data_line = NULL;
@@ -715,8 +714,6 @@ static int pblk_lines_init(struct pblk *pblk)
 
 	pblk_set_provision(pblk, nr_free_blks);
 
-	sema_init(&pblk->erase_sem, 1);
-
 	/* Cleanup per-LUN bad block lists - managed within lines on run-time */
 	for (i = 0; i < geo->nr_luns; i++)
 		kfree(pblk->luns[i].bb_list);
diff --git a/drivers/lightnvm/pblk-map.c b/drivers/lightnvm/pblk-map.c
index 18291c238930..84309bd400d5 100644
--- a/drivers/lightnvm/pblk-map.c
+++ b/drivers/lightnvm/pblk-map.c
@@ -92,8 +92,9 @@ void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
 {
 	struct nvm_tgt_dev *dev = pblk->dev;
 	struct nvm_geo *geo = &dev->geo;
-	struct pblk_line *e_line = pblk_line_get_data_next(pblk);
+	struct pblk_line_meta *lm = &pblk->lm;
 	struct pblk_sec_meta *meta_list = rqd->meta_list;
+	struct pblk_line *e_line, *d_line;
 	unsigned int map_secs;
 	int min = pblk->min_write_pgs;
 	int i, erase_lun;
@@ -106,32 +107,49 @@ void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
 		erase_lun = rqd->ppa_list[i].g.lun * geo->nr_chnls +
 							rqd->ppa_list[i].g.ch;
 
+		/* line can change after page map */
+		e_line = pblk_line_get_erase(pblk);
+		spin_lock(&e_line->lock);
 		if (!test_bit(erase_lun, e_line->erase_bitmap)) {
-			if (down_trylock(&pblk->erase_sem))
-				continue;
-
 			set_bit(erase_lun, e_line->erase_bitmap);
 			atomic_dec(&e_line->left_eblks);
+
 			*erase_ppa = rqd->ppa_list[i];
 			erase_ppa->g.blk = e_line->id;
 
+			spin_unlock(&e_line->lock);
+
 			/* Avoid evaluating e_line->left_eblks */
 			return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
 							valid_secs, i + min);
 		}
+		spin_unlock(&e_line->lock);
 	}
 
+	e_line = pblk_line_get_erase(pblk);
+	d_line = pblk_line_get_data(pblk);
+
 	/* Erase blocks that are bad in this line but might not be in next */
-	if (unlikely(ppa_empty(*erase_ppa))) {
-		struct pblk_line_meta *lm = &pblk->lm;
+	if (unlikely(ppa_empty(*erase_ppa)) &&
+			bitmap_weight(d_line->blk_bitmap, lm->blk_per_line)) {
+		int bit = -1;
 
-		i = find_first_zero_bit(e_line->erase_bitmap, lm->blk_per_line);
-		if (i == lm->blk_per_line)
+retry:
+		bit = find_next_bit(d_line->blk_bitmap,
+						lm->blk_per_line, bit + 1);
+		if (bit >= lm->blk_per_line)
 			return;
 
-		set_bit(i, e_line->erase_bitmap);
+		spin_lock(&e_line->lock);
+		if (test_bit(bit, e_line->erase_bitmap)) {
+			spin_unlock(&e_line->lock);
+			goto retry;
+		}
+		spin_unlock(&e_line->lock);
+
+		set_bit(bit, e_line->erase_bitmap);
 		atomic_dec(&e_line->left_eblks);
-		*erase_ppa = pblk->luns[i].bppa; /* set ch and lun */
+		*erase_ppa = pblk->luns[bit].bppa; /* set ch and lun */
 		erase_ppa->g.blk = e_line->id;
 	}
 }
diff --git a/drivers/lightnvm/pblk-rb.c b/drivers/lightnvm/pblk-rb.c
index 045384ddc1f9..d293af12aa7a 100644
--- a/drivers/lightnvm/pblk-rb.c
+++ b/drivers/lightnvm/pblk-rb.c
@@ -521,20 +521,19 @@ unsigned int pblk_rb_read_to_bio_list(struct pblk_rb *rb, struct bio *bio,
  * This function is used by the write thread to form the write bio that will
  * persist data on the write buffer to the media.
  */
-unsigned int pblk_rb_read_to_bio(struct pblk_rb *rb, struct bio *bio,
-				 struct pblk_c_ctx *c_ctx,
-				 unsigned int pos,
-				 unsigned int nr_entries,
-				 unsigned int count)
+unsigned int pblk_rb_read_to_bio(struct pblk_rb *rb, struct nvm_rq *rqd,
+				 struct bio *bio, unsigned int pos,
+				 unsigned int nr_entries, unsigned int count)
 {
 	struct pblk *pblk = container_of(rb, struct pblk, rwb);
+	struct request_queue *q = pblk->dev->q;
+	struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
 	struct pblk_rb_entry *entry;
 	struct page *page;
-	unsigned int pad = 0, read = 0, to_read = nr_entries;
+	unsigned int pad = 0, to_read = nr_entries;
 	unsigned int user_io = 0, gc_io = 0;
 	unsigned int i;
 	int flags;
-	int ret;
 
 	if (count < nr_entries) {
 		pad = nr_entries - count;
@@ -570,17 +569,17 @@ unsigned int pblk_rb_read_to_bio(struct pblk_rb *rb, struct bio *bio,
 			flags |= PBLK_SUBMITTED_ENTRY;
 			/* Release flags on context. Protect from writes */
 			smp_store_release(&entry->w_ctx.flags, flags);
-			goto out;
+			return NVM_IO_ERR;
 		}
 
-		ret = bio_add_page(bio, page, rb->seg_size, 0);
-		if (ret != rb->seg_size) {
+		if (bio_add_pc_page(q, bio, page, rb->seg_size, 0) !=
+								rb->seg_size) {
 			pr_err("pblk: could not add page to write bio\n");
 			flags &= ~PBLK_WRITTEN_DATA;
 			flags |= PBLK_SUBMITTED_ENTRY;
 			/* Release flags on context. Protect from writes */
 			smp_store_release(&entry->w_ctx.flags, flags);
-			goto out;
+			return NVM_IO_ERR;
 		}
 
 		if (flags & PBLK_FLUSH_ENTRY) {
@@ -607,14 +606,20 @@ unsigned int pblk_rb_read_to_bio(struct pblk_rb *rb, struct bio *bio,
 		pos = (pos + 1) & (rb->nr_entries - 1);
 	}
 
-	read = to_read;
+	if (pad) {
+		if (pblk_bio_add_pages(pblk, bio, GFP_KERNEL, pad)) {
+			pr_err("pblk: could not pad page in write bio\n");
+			return NVM_IO_ERR;
+		}
+	}
+
 	pblk_rl_out(&pblk->rl, user_io, gc_io);
 #ifdef CONFIG_NVM_DEBUG
 	atomic_long_add(pad, &((struct pblk *)
 			(container_of(rb, struct pblk, rwb)))->padded_writes);
 #endif
-out:
-	return read;
+
+	return NVM_IO_OK;
 }
 
 /*
diff --git a/drivers/lightnvm/pblk-write.c b/drivers/lightnvm/pblk-write.c
index 79b90d8dbcb3..c745a22057f8 100644
--- a/drivers/lightnvm/pblk-write.c
+++ b/drivers/lightnvm/pblk-write.c
@@ -219,11 +219,10 @@ static int pblk_alloc_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
 }
 
 static int pblk_setup_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
-			   struct pblk_c_ctx *c_ctx)
+			   struct pblk_c_ctx *c_ctx, struct ppa_addr *erase_ppa)
 {
 	struct pblk_line_meta *lm = &pblk->lm;
-	struct pblk_line *e_line = pblk_line_get_data_next(pblk);
-	struct ppa_addr erase_ppa;
+	struct pblk_line *e_line = pblk_line_get_erase(pblk);
 	unsigned int valid = c_ctx->nr_valid;
 	unsigned int padded = c_ctx->nr_padded;
 	unsigned int nr_secs = valid + padded;
@@ -231,40 +230,23 @@ static int pblk_setup_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
 	int ret = 0;
 
 	lun_bitmap = kzalloc(lm->lun_bitmap_len, GFP_KERNEL);
-	if (!lun_bitmap) {
-		ret = -ENOMEM;
-		goto out;
-	}
+	if (!lun_bitmap)
+		return -ENOMEM;
 	c_ctx->lun_bitmap = lun_bitmap;
 
 	ret = pblk_alloc_w_rq(pblk, rqd, nr_secs);
 	if (ret) {
 		kfree(lun_bitmap);
-		goto out;
+		return ret;
 	}
 
-	ppa_set_empty(&erase_ppa);
-	if (likely(!e_line || !atomic_read(&e_line->left_eblks)))
+	if (likely(!atomic_read(&e_line->left_eblks) || !e_line))
 		pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, valid, 0);
 	else
 		pblk_map_erase_rq(pblk, rqd, c_ctx->sentry, lun_bitmap,
-							valid, &erase_ppa);
+							valid, erase_ppa);
 
-out:
-	if (unlikely(e_line && !ppa_empty(erase_ppa))) {
-		if (pblk_blk_erase_async(pblk, erase_ppa)) {
-			struct nvm_tgt_dev *dev = pblk->dev;
-			struct nvm_geo *geo = &dev->geo;
-			int bit;
-
-			atomic_inc(&e_line->left_eblks);
-			bit = erase_ppa.g.lun * geo->nr_chnls + erase_ppa.g.ch;
-			WARN_ON(!test_and_clear_bit(bit, e_line->erase_bitmap));
-			up(&pblk->erase_sem);
-		}
-	}
-
-	return ret;
+	return 0;
 }
 
 int pblk_setup_w_rec_rq(struct pblk *pblk, struct nvm_rq *rqd,
@@ -311,16 +293,60 @@ static int pblk_calc_secs_to_sync(struct pblk *pblk, unsigned int secs_avail,
 	return secs_to_sync;
 }
 
+static int pblk_submit_io_set(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
+	struct ppa_addr erase_ppa;
+	int err;
+
+	ppa_set_empty(&erase_ppa);
+
+	/* Assign lbas to ppas and populate request structure */
+	err = pblk_setup_w_rq(pblk, rqd, c_ctx, &erase_ppa);
+	if (err) {
+		pr_err("pblk: could not setup write request: %d\n", err);
+		return NVM_IO_ERR;
+	}
+
+	/* Submit write for current data line */
+	err = pblk_submit_io(pblk, rqd);
+	if (err) {
+		pr_err("pblk: I/O submission failed: %d\n", err);
+		return NVM_IO_ERR;
+	}
+
+	/* Submit available erase for next data line */
+	if (unlikely(!ppa_empty(erase_ppa)) &&
+				pblk_blk_erase_async(pblk, erase_ppa)) {
+		struct pblk_line *e_line = pblk_line_get_erase(pblk);
+		struct nvm_tgt_dev *dev = pblk->dev;
+		struct nvm_geo *geo = &dev->geo;
+		int bit;
+
+		atomic_inc(&e_line->left_eblks);
+		bit = erase_ppa.g.lun * geo->nr_chnls + erase_ppa.g.ch;
+		WARN_ON(!test_and_clear_bit(bit, e_line->erase_bitmap));
+	}
+
+	return NVM_IO_OK;
+}
+
+static void pblk_free_write_rqd(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
+	struct bio *bio = rqd->bio;
+
+	if (c_ctx->nr_padded)
+		pblk_bio_free_pages(pblk, bio, rqd->nr_ppas, c_ctx->nr_padded);
+}
+
 static int pblk_submit_write(struct pblk *pblk)
 {
 	struct bio *bio;
 	struct nvm_rq *rqd;
-	struct pblk_c_ctx *c_ctx;
-	unsigned int pgs_read;
 	unsigned int secs_avail, secs_to_sync, secs_to_com;
 	unsigned int secs_to_flush;
 	unsigned long pos;
-	int err;
 
 	/* If there are no sectors in the cache, flushes (bios without data)
 	 * will be cleared on the cache threads
@@ -338,7 +364,6 @@ static int pblk_submit_write(struct pblk *pblk)
 		pr_err("pblk: cannot allocate write req.\n");
 		return 1;
 	}
-	c_ctx = nvm_rq_to_pdu(rqd);
 
 	bio = bio_alloc(GFP_KERNEL, pblk->max_write_pgs);
 	if (!bio) {
@@ -358,29 +383,14 @@ static int pblk_submit_write(struct pblk *pblk)
 	secs_to_com = (secs_to_sync > secs_avail) ? secs_avail : secs_to_sync;
 	pos = pblk_rb_read_commit(&pblk->rwb, secs_to_com);
 
-	pgs_read = pblk_rb_read_to_bio(&pblk->rwb, bio, c_ctx, pos,
-						secs_to_sync, secs_avail);
-	if (!pgs_read) {
+	if (pblk_rb_read_to_bio(&pblk->rwb, rqd, bio, pos, secs_to_sync,
+								secs_avail)) {
 		pr_err("pblk: corrupted write bio\n");
 		goto fail_put_bio;
 	}
 
-	if (c_ctx->nr_padded)
-		if (pblk_bio_add_pages(pblk, bio, GFP_KERNEL, c_ctx->nr_padded))
-			goto fail_put_bio;
-
-	/* Assign lbas to ppas and populate request structure */
-	err = pblk_setup_w_rq(pblk, rqd, c_ctx);
-	if (err) {
-		pr_err("pblk: could not setup write request\n");
+	if (pblk_submit_io_set(pblk, rqd))
 		goto fail_free_bio;
-	}
-
-	err = pblk_submit_io(pblk, rqd);
-	if (err) {
-		pr_err("pblk: I/O submission failed: %d\n", err);
-		goto fail_free_bio;
-	}
 
 #ifdef CONFIG_NVM_DEBUG
 	atomic_long_add(secs_to_sync, &pblk->sub_writes);
@@ -389,8 +399,7 @@ static int pblk_submit_write(struct pblk *pblk)
 	return 0;
 
 fail_free_bio:
-	if (c_ctx->nr_padded)
-		pblk_bio_free_pages(pblk, bio, secs_to_sync, c_ctx->nr_padded);
+	pblk_free_write_rqd(pblk, rqd);
 fail_put_bio:
 	bio_put(bio);
 fail_free_rqd:
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index c18fda522b34..de0361988bfb 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -500,7 +500,6 @@ struct pblk {
 	struct pblk_rl rl;
 
 	int sec_per_write;
-	struct semaphore erase_sem;
 
 	unsigned char instance_uuid[16];
 #ifdef CONFIG_NVM_DEBUG
@@ -583,11 +582,9 @@ void pblk_rb_write_entry_gc(struct pblk_rb *rb, void *data,
 struct pblk_w_ctx *pblk_rb_w_ctx(struct pblk_rb *rb, unsigned int pos);
 
 void pblk_rb_sync_l2p(struct pblk_rb *rb);
-unsigned int pblk_rb_read_to_bio(struct pblk_rb *rb, struct bio *bio,
-				 struct pblk_c_ctx *c_ctx,
-				 unsigned int pos,
-				 unsigned int nr_entries,
-				 unsigned int count);
+unsigned int pblk_rb_read_to_bio(struct pblk_rb *rb, struct nvm_rq *rqd,
+				 struct bio *bio, unsigned int pos,
+				 unsigned int nr_entries, unsigned int count);
 unsigned int pblk_rb_read_to_bio_list(struct pblk_rb *rb, struct bio *bio,
 				      struct list_head *list,
 				      unsigned int max);
@@ -633,7 +630,7 @@ struct pblk_line *pblk_line_replace_data(struct pblk *pblk);
 int pblk_line_recov_alloc(struct pblk *pblk, struct pblk_line *line);
 void pblk_line_recov_close(struct pblk *pblk, struct pblk_line *line);
 struct pblk_line *pblk_line_get_data(struct pblk *pblk);
-struct pblk_line *pblk_line_get_data_next(struct pblk *pblk);
+struct pblk_line *pblk_line_get_erase(struct pblk *pblk);
 int pblk_line_erase(struct pblk *pblk, struct pblk_line *line);
 int pblk_line_is_full(struct pblk_line *line);
 void pblk_line_free(struct pblk *pblk, struct pblk_line *line);
-- 
2.7.4

[PATCH 07/20] lightnvm: pblk: rename read request pool

[Javier González]

Read requests allocate some extra memory to store its per I/O context.
Instead of requiring yet another memory pool for other type of requests,
generalize this context allocation (and change naming accordingly).

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/pblk-core.c     | 12 ++++++------
 drivers/lightnvm/pblk-init.c     | 24 ++++++++++++------------
 drivers/lightnvm/pblk-read.c     | 17 +++++++++--------
 drivers/lightnvm/pblk-recovery.c |  8 ++++----
 drivers/lightnvm/pblk.h          | 12 ++++++------
 5 files changed, 37 insertions(+), 36 deletions(-)

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index a1125547e638..6fa51eb9d681 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -62,7 +62,7 @@ static void pblk_end_io_erase(struct nvm_rq *rqd)
 	struct pblk *pblk = rqd->private;
 
 	__pblk_end_io_erase(pblk, rqd);
-	mempool_free(rqd, pblk->r_rq_pool);
+	mempool_free(rqd, pblk->g_rq_pool);
 }
 
 static void __pblk_map_invalidate(struct pblk *pblk, struct pblk_line *line,
@@ -171,8 +171,8 @@ struct nvm_rq *pblk_alloc_rqd(struct pblk *pblk, int rw)
 		pool = pblk->w_rq_pool;
 		rq_size = pblk_w_rq_size;
 	} else {
-		pool = pblk->r_rq_pool;
-		rq_size = pblk_r_rq_size;
+		pool = pblk->g_rq_pool;
+		rq_size = pblk_g_rq_size;
 	}
 
 	rqd = mempool_alloc(pool, GFP_KERNEL);
@@ -188,7 +188,7 @@ void pblk_free_rqd(struct pblk *pblk, struct nvm_rq *rqd, int rw)
 	if (rw == WRITE)
 		pool = pblk->w_rq_pool;
 	else
-		pool = pblk->r_rq_pool;
+		pool = pblk->g_rq_pool;
 
 	mempool_free(rqd, pool);
 }
@@ -1343,8 +1343,8 @@ int pblk_blk_erase_async(struct pblk *pblk, struct ppa_addr ppa)
 	struct nvm_rq *rqd;
 	int err;
 
-	rqd = mempool_alloc(pblk->r_rq_pool, GFP_KERNEL);
-	memset(rqd, 0, pblk_r_rq_size);
+	rqd = mempool_alloc(pblk->g_rq_pool, GFP_KERNEL);
+	memset(rqd, 0, pblk_g_rq_size);
 
 	pblk_setup_e_rq(pblk, rqd, ppa);
 
diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
index 5ea610957fb3..51dd42c7e852 100644
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -20,7 +20,7 @@
 
 #include "pblk.h"
 
-static struct kmem_cache *pblk_blk_ws_cache, *pblk_rec_cache, *pblk_r_rq_cache,
+static struct kmem_cache *pblk_blk_ws_cache, *pblk_rec_cache, *pblk_g_rq_cache,
 					*pblk_w_rq_cache, *pblk_line_meta_cache;
 static DECLARE_RWSEM(pblk_lock);
 
@@ -199,9 +199,9 @@ static int pblk_init_global_caches(struct pblk *pblk)
 		return -ENOMEM;
 	}
 
-	pblk_r_rq_cache = kmem_cache_create("pblk_r_rq", pblk_r_rq_size,
+	pblk_g_rq_cache = kmem_cache_create("pblk_g_rq", pblk_g_rq_size,
 				0, 0, NULL);
-	if (!pblk_r_rq_cache) {
+	if (!pblk_g_rq_cache) {
 		kmem_cache_destroy(pblk_blk_ws_cache);
 		kmem_cache_destroy(pblk_rec_cache);
 		up_write(&pblk_lock);
@@ -213,7 +213,7 @@ static int pblk_init_global_caches(struct pblk *pblk)
 	if (!pblk_w_rq_cache) {
 		kmem_cache_destroy(pblk_blk_ws_cache);
 		kmem_cache_destroy(pblk_rec_cache);
-		kmem_cache_destroy(pblk_r_rq_cache);
+		kmem_cache_destroy(pblk_g_rq_cache);
 		up_write(&pblk_lock);
 		return -ENOMEM;
 	}
@@ -225,7 +225,7 @@ static int pblk_init_global_caches(struct pblk *pblk)
 	if (!pblk_line_meta_cache) {
 		kmem_cache_destroy(pblk_blk_ws_cache);
 		kmem_cache_destroy(pblk_rec_cache);
-		kmem_cache_destroy(pblk_r_rq_cache);
+		kmem_cache_destroy(pblk_g_rq_cache);
 		kmem_cache_destroy(pblk_w_rq_cache);
 		up_write(&pblk_lock);
 		return -ENOMEM;
@@ -278,13 +278,13 @@ static int pblk_core_init(struct pblk *pblk)
 	if (!pblk->rec_pool)
 		goto free_blk_ws_pool;
 
-	pblk->r_rq_pool = mempool_create_slab_pool(64, pblk_r_rq_cache);
-	if (!pblk->r_rq_pool)
+	pblk->g_rq_pool = mempool_create_slab_pool(64, pblk_g_rq_cache);
+	if (!pblk->g_rq_pool)
 		goto free_rec_pool;
 
 	pblk->w_rq_pool = mempool_create_slab_pool(64, pblk_w_rq_cache);
 	if (!pblk->w_rq_pool)
-		goto free_r_rq_pool;
+		goto free_g_rq_pool;
 
 	pblk->line_meta_pool =
 			mempool_create_slab_pool(16, pblk_line_meta_cache);
@@ -311,8 +311,8 @@ static int pblk_core_init(struct pblk *pblk)
 	mempool_destroy(pblk->line_meta_pool);
 free_w_rq_pool:
 	mempool_destroy(pblk->w_rq_pool);
-free_r_rq_pool:
-	mempool_destroy(pblk->r_rq_pool);
+free_g_rq_pool:
+	mempool_destroy(pblk->g_rq_pool);
 free_rec_pool:
 	mempool_destroy(pblk->rec_pool);
 free_blk_ws_pool:
@@ -330,13 +330,13 @@ static void pblk_core_free(struct pblk *pblk)
 	mempool_destroy(pblk->page_pool);
 	mempool_destroy(pblk->line_ws_pool);
 	mempool_destroy(pblk->rec_pool);
-	mempool_destroy(pblk->r_rq_pool);
+	mempool_destroy(pblk->g_rq_pool);
 	mempool_destroy(pblk->w_rq_pool);
 	mempool_destroy(pblk->line_meta_pool);
 
 	kmem_cache_destroy(pblk_blk_ws_cache);
 	kmem_cache_destroy(pblk_rec_cache);
-	kmem_cache_destroy(pblk_r_rq_cache);
+	kmem_cache_destroy(pblk_g_rq_cache);
 	kmem_cache_destroy(pblk_w_rq_cache);
 	kmem_cache_destroy(pblk_line_meta_cache);
 }
diff --git a/drivers/lightnvm/pblk-read.c b/drivers/lightnvm/pblk-read.c
index 91307297e444..cea958e96fc3 100644
--- a/drivers/lightnvm/pblk-read.c
+++ b/drivers/lightnvm/pblk-read.c
@@ -110,7 +110,7 @@ static void pblk_end_io_read(struct nvm_rq *rqd)
 {
 	struct pblk *pblk = rqd->private;
 	struct nvm_tgt_dev *dev = pblk->dev;
-	struct pblk_r_ctx *r_ctx = nvm_rq_to_pdu(rqd);
+	struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
 	struct bio *bio = rqd->bio;
 
 	if (rqd->error)
@@ -124,13 +124,14 @@ static void pblk_end_io_read(struct nvm_rq *rqd)
 		nvm_dev_dma_free(dev->parent, rqd->ppa_list, rqd->dma_ppa_list);
 
 	bio_put(bio);
-	if (r_ctx->orig_bio) {
+	if (r_ctx->private) {
+		struct bio *orig_bio = r_ctx->private;
+
 #ifdef CONFIG_NVM_DEBUG
-		WARN_ONCE(r_ctx->orig_bio->bi_status,
-						"pblk: corrupted read bio\n");
+		WARN_ONCE(orig_bio->bi_status, "pblk: corrupted read bio\n");
 #endif
-		bio_endio(r_ctx->orig_bio);
-		bio_put(r_ctx->orig_bio);
+		bio_endio(orig_bio);
+		bio_put(orig_bio);
 	}
 
 #ifdef CONFIG_NVM_DEBUG
@@ -345,7 +346,7 @@ int pblk_submit_read(struct pblk *pblk, struct bio *bio)
 	/* All sectors are to be read from the device */
 	if (bitmap_empty(&read_bitmap, rqd->nr_ppas)) {
 		struct bio *int_bio = NULL;
-		struct pblk_r_ctx *r_ctx = nvm_rq_to_pdu(rqd);
+		struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
 
 		/* Clone read bio to deal with read errors internally */
 		int_bio = bio_clone_bioset(bio, GFP_KERNEL, fs_bio_set);
@@ -355,7 +356,7 @@ int pblk_submit_read(struct pblk *pblk, struct bio *bio)
 		}
 
 		rqd->bio = int_bio;
-		r_ctx->orig_bio = bio;
+		r_ctx->private = bio;
 
 		ret = pblk_submit_read_io(pblk, rqd);
 		if (ret) {
diff --git a/drivers/lightnvm/pblk-recovery.c b/drivers/lightnvm/pblk-recovery.c
index 82787006b865..84671b44bddb 100644
--- a/drivers/lightnvm/pblk-recovery.c
+++ b/drivers/lightnvm/pblk-recovery.c
@@ -240,7 +240,7 @@ static int pblk_recov_read_oob(struct pblk *pblk, struct pblk_line *line,
 	r_ptr_int = r_ptr;
 
 next_read_rq:
-	memset(rqd, 0, pblk_r_rq_size);
+	memset(rqd, 0, pblk_g_rq_size);
 
 	rq_ppas = pblk_calc_secs(pblk, left_ppas, 0);
 	if (!rq_ppas)
@@ -361,7 +361,7 @@ static int pblk_recov_pad_oob(struct pblk *pblk, struct pblk_line *line,
 	bio->bi_iter.bi_sector = 0; /* internal bio */
 	bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
 
-	memset(rqd, 0, pblk_r_rq_size);
+	memset(rqd, 0, pblk_g_rq_size);
 
 	rqd->bio = bio;
 	rqd->opcode = NVM_OP_PWRITE;
@@ -456,7 +456,7 @@ static int pblk_recov_scan_all_oob(struct pblk *pblk, struct pblk_line *line,
 	rec_round = 0;
 
 next_rq:
-	memset(rqd, 0, pblk_r_rq_size);
+	memset(rqd, 0, pblk_g_rq_size);
 
 	rq_ppas = pblk_calc_secs(pblk, left_ppas, 0);
 	if (!rq_ppas)
@@ -591,7 +591,7 @@ static int pblk_recov_scan_oob(struct pblk *pblk, struct pblk_line *line,
 	*done = 1;
 
 next_rq:
-	memset(rqd, 0, pblk_r_rq_size);
+	memset(rqd, 0, pblk_g_rq_size);
 
 	rq_ppas = pblk_calc_secs(pblk, left_ppas, 0);
 	if (!rq_ppas)
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index de0361988bfb..136cc2ed5b2f 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -91,7 +91,7 @@ struct pblk_sec_meta {
 
 #define pblk_dma_meta_size (sizeof(struct pblk_sec_meta) * PBLK_MAX_REQ_ADDRS)
 
-/* write completion context */
+/* write buffer completion context */
 struct pblk_c_ctx {
 	struct list_head list;		/* Head for out-of-order completion */
 
@@ -101,9 +101,9 @@ struct pblk_c_ctx {
 	unsigned int nr_padded;
 };
 
-/* Read context */
-struct pblk_r_ctx {
-	struct bio *orig_bio;
+/* generic context */
+struct pblk_g_ctx {
+	void *private;
 };
 
 /* Recovery context */
@@ -543,7 +543,7 @@ struct pblk {
 	mempool_t *page_pool;
 	mempool_t *line_ws_pool;
 	mempool_t *rec_pool;
-	mempool_t *r_rq_pool;
+	mempool_t *g_rq_pool;
 	mempool_t *w_rq_pool;
 	mempool_t *line_meta_pool;
 
@@ -560,7 +560,7 @@ struct pblk_line_ws {
 	struct work_struct ws;
 };
 
-#define pblk_r_rq_size (sizeof(struct nvm_rq) + sizeof(struct pblk_r_ctx))
+#define pblk_g_rq_size (sizeof(struct nvm_rq) + sizeof(struct pblk_g_ctx))
 #define pblk_w_rq_size (sizeof(struct nvm_rq) + sizeof(struct pblk_c_ctx))
 
 /*
-- 
2.7.4

[PATCH 08/20] lightnvm: pblk: sched. metadata on write thread

[Javier González]

At the moment, line metadata is persisted on a separate work queue, that
is kicked each time that a line is closed. The assumption when designing
this was that freeing the write thread from creating a new write request
was better than the potential impact of writes colliding on the media
(user I/O and metadata I/O). Experimentation has proven that this
assumption is wrong; collision can cause up to 25% of bandwidth and
introduce long tail latencies on the write thread, which potentially
cause user write threads to spend more time spinning to get a free entry
on the write buffer.

This patch moves the metadata logic to the write thread. When a line is
closed, remaining metadata is written in memory and is placed on a
metadata queue. The write thread then takes the metadata corresponding
to the previous line, creates the write request and schedules it to
minimize collisions on the media. Using this approach, we see that we
can saturate the media's bandwidth, which helps reducing both write
latencies and the spinning time for user writer threads.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/pblk-core.c     | 216 ++++++++++++++++++++-------------
 drivers/lightnvm/pblk-gc.c       |  41 +++----
 drivers/lightnvm/pblk-init.c     | 240 ++++++++++++++++++++++---------------
 drivers/lightnvm/pblk-map.c      |  13 +-
 drivers/lightnvm/pblk-recovery.c |  67 ++++++-----
 drivers/lightnvm/pblk-sysfs.c    |  16 ++-
 drivers/lightnvm/pblk-write.c    | 249 +++++++++++++++++++++++++++++++++++----
 drivers/lightnvm/pblk.h          | 114 +++++++++++++-----
 8 files changed, 672 insertions(+), 284 deletions(-)

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index 6fa51eb9d681..6e4b06f841e7 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -87,7 +87,7 @@ static void __pblk_map_invalidate(struct pblk *pblk, struct pblk_line *line,
 		spin_unlock(&line->lock);
 		return;
 	}
-	line->vsc--;
+	le32_add_cpu(line->vsc, -1);
 
 	if (line->state == PBLK_LINESTATE_CLOSED)
 		move_list = pblk_line_gc_list(pblk, line);
@@ -306,28 +306,29 @@ struct list_head *pblk_line_gc_list(struct pblk *pblk, struct pblk_line *line)
 	struct pblk_line_meta *lm = &pblk->lm;
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 	struct list_head *move_list = NULL;
+	int vsc = le32_to_cpu(*line->vsc);
 
-	if (!line->vsc) {
+	if (!vsc) {
 		if (line->gc_group != PBLK_LINEGC_FULL) {
 			line->gc_group = PBLK_LINEGC_FULL;
 			move_list = &l_mg->gc_full_list;
 		}
-	} else if (line->vsc < lm->mid_thrs) {
+	} else if (vsc < lm->mid_thrs) {
 		if (line->gc_group != PBLK_LINEGC_HIGH) {
 			line->gc_group = PBLK_LINEGC_HIGH;
 			move_list = &l_mg->gc_high_list;
 		}
-	} else if (line->vsc < lm->high_thrs) {
+	} else if (vsc < lm->high_thrs) {
 		if (line->gc_group != PBLK_LINEGC_MID) {
 			line->gc_group = PBLK_LINEGC_MID;
 			move_list = &l_mg->gc_mid_list;
 		}
-	} else if (line->vsc < line->sec_in_line) {
+	} else if (vsc < line->sec_in_line) {
 		if (line->gc_group != PBLK_LINEGC_LOW) {
 			line->gc_group = PBLK_LINEGC_LOW;
 			move_list = &l_mg->gc_low_list;
 		}
-	} else if (line->vsc == line->sec_in_line) {
+	} else if (vsc == line->sec_in_line) {
 		if (line->gc_group != PBLK_LINEGC_EMPTY) {
 			line->gc_group = PBLK_LINEGC_EMPTY;
 			move_list = &l_mg->gc_empty_list;
@@ -337,7 +338,7 @@ struct list_head *pblk_line_gc_list(struct pblk *pblk, struct pblk_line *line)
 		line->gc_group = PBLK_LINEGC_NONE;
 		move_list =  &l_mg->corrupt_list;
 		pr_err("pblk: corrupted vsc for line %d, vsc:%d (%d/%d/%d)\n",
-						line->id, line->vsc,
+						line->id, vsc,
 						line->sec_in_line,
 						lm->high_thrs, lm->mid_thrs);
 	}
@@ -496,8 +497,20 @@ int pblk_calc_secs(struct pblk *pblk, unsigned long secs_avail,
 	return secs_to_sync;
 }
 
-static u64 __pblk_alloc_page(struct pblk *pblk, struct pblk_line *line,
-			     int nr_secs)
+void pblk_dealloc_page(struct pblk *pblk, struct pblk_line *line, int nr_secs)
+{
+	u64 addr;
+	int i;
+
+	addr = find_next_zero_bit(line->map_bitmap,
+					pblk->lm.sec_per_line, line->cur_sec);
+	line->cur_sec = addr - nr_secs;
+
+	for (i = 0; i < nr_secs; i++, line->cur_sec--)
+		WARN_ON(!test_and_clear_bit(line->cur_sec, line->map_bitmap));
+}
+
+u64 __pblk_alloc_page(struct pblk *pblk, struct pblk_line *line, int nr_secs)
 {
 	u64 addr;
 	int i;
@@ -532,12 +545,24 @@ u64 pblk_alloc_page(struct pblk *pblk, struct pblk_line *line, int nr_secs)
 	return addr;
 }
 
+u64 pblk_lookup_page(struct pblk *pblk, struct pblk_line *line)
+{
+	u64 paddr;
+
+	spin_lock(&line->lock);
+	paddr = find_next_zero_bit(line->map_bitmap,
+					pblk->lm.sec_per_line, line->cur_sec);
+	spin_unlock(&line->lock);
+
+	return paddr;
+}
+
 /*
  * Submit emeta to one LUN in the raid line at the time to avoid a deadlock when
  * taking the per LUN semaphore.
  */
 static int pblk_line_submit_emeta_io(struct pblk *pblk, struct pblk_line *line,
-				     u64 paddr, int dir)
+				     void *emeta_buf, u64 paddr, int dir)
 {
 	struct nvm_tgt_dev *dev = pblk->dev;
 	struct nvm_geo *geo = &dev->geo;
@@ -546,9 +571,8 @@ static int pblk_line_submit_emeta_io(struct pblk *pblk, struct pblk_line *line,
 	struct nvm_rq rqd;
 	struct ppa_addr *ppa_list;
 	dma_addr_t dma_ppa_list;
-	void *emeta = line->emeta;
 	int min = pblk->min_write_pgs;
-	int left_ppas = lm->emeta_sec;
+	int left_ppas = lm->emeta_sec[0];
 	int id = line->id;
 	int rq_ppas, rq_len;
 	int cmd_op, bio_op;
@@ -578,7 +602,7 @@ static int pblk_line_submit_emeta_io(struct pblk *pblk, struct pblk_line *line,
 	rq_ppas = pblk_calc_secs(pblk, left_ppas, 0);
 	rq_len = rq_ppas * geo->sec_size;
 
-	bio = pblk_bio_map_addr(pblk, emeta, rq_ppas, rq_len, GFP_KERNEL);
+	bio = pblk_bio_map_addr(pblk, emeta_buf, rq_ppas, rq_len, GFP_KERNEL);
 	if (IS_ERR(bio)) {
 		ret = PTR_ERR(bio);
 		goto free_rqd_dma;
@@ -660,7 +684,7 @@ static int pblk_line_submit_emeta_io(struct pblk *pblk, struct pblk_line *line,
 			pblk_log_read_err(pblk, &rqd);
 	}
 
-	emeta += rq_len;
+	emeta_buf += rq_len;
 	left_ppas -= rq_ppas;
 	if (left_ppas)
 		goto next_rq;
@@ -701,7 +725,7 @@ static int pblk_line_submit_smeta_io(struct pblk *pblk, struct pblk_line *line,
 		bio_op = REQ_OP_WRITE;
 		cmd_op = NVM_OP_PWRITE;
 		flags = pblk_set_progr_mode(pblk, WRITE);
-		lba_list = pblk_line_emeta_to_lbas(line->emeta);
+		lba_list = emeta_to_lbas(pblk, line->emeta->buf);
 	} else if (dir == READ) {
 		bio_op = REQ_OP_READ;
 		cmd_op = NVM_OP_PREAD;
@@ -775,9 +799,11 @@ int pblk_line_read_smeta(struct pblk *pblk, struct pblk_line *line)
 	return pblk_line_submit_smeta_io(pblk, line, bpaddr, READ);
 }
 
-int pblk_line_read_emeta(struct pblk *pblk, struct pblk_line *line)
+int pblk_line_read_emeta(struct pblk *pblk, struct pblk_line *line,
+			 void *emeta_buf)
 {
-	return pblk_line_submit_emeta_io(pblk, line, line->emeta_ssec, READ);
+	return pblk_line_submit_emeta_io(pblk, line, emeta_buf,
+						line->emeta_ssec, READ);
 }
 
 static void pblk_setup_e_rq(struct pblk *pblk, struct nvm_rq *rqd,
@@ -863,18 +889,47 @@ int pblk_line_erase(struct pblk *pblk, struct pblk_line *line)
 	return 0;
 }
 
+static void pblk_line_setup_metadata(struct pblk_line *line,
+				     struct pblk_line_mgmt *l_mg,
+				     struct pblk_line_meta *lm)
+{
+	int meta_line;
+
+retry_meta:
+	meta_line = find_first_zero_bit(&l_mg->meta_bitmap, PBLK_DATA_LINES);
+	if (meta_line == PBLK_DATA_LINES) {
+		spin_unlock(&l_mg->free_lock);
+		io_schedule();
+		spin_lock(&l_mg->free_lock);
+		goto retry_meta;
+	}
+
+	set_bit(meta_line, &l_mg->meta_bitmap);
+	line->meta_line = meta_line;
+
+	line->smeta = l_mg->sline_meta[meta_line];
+	line->emeta = l_mg->eline_meta[meta_line];
+
+	memset(line->smeta, 0, lm->smeta_len);
+	memset(line->emeta->buf, 0, lm->emeta_len[0]);
+
+	line->emeta->mem = 0;
+	atomic_set(&line->emeta->sync, 0);
+}
+
 /* For now lines are always assumed full lines. Thus, smeta former and current
  * lun bitmaps are omitted.
  */
-static int pblk_line_set_metadata(struct pblk *pblk, struct pblk_line *line,
+static int pblk_line_init_metadata(struct pblk *pblk, struct pblk_line *line,
 				  struct pblk_line *cur)
 {
 	struct nvm_tgt_dev *dev = pblk->dev;
 	struct nvm_geo *geo = &dev->geo;
 	struct pblk_line_meta *lm = &pblk->lm;
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
-	struct line_smeta *smeta = line->smeta;
-	struct line_emeta *emeta = line->emeta;
+	struct pblk_emeta *emeta = line->emeta;
+	struct line_emeta *emeta_buf = emeta->buf;
+	struct line_smeta *smeta_buf = (struct line_smeta *)line->smeta;
 	int nr_blk_line;
 
 	/* After erasing the line, new bad blocks might appear and we risk
@@ -897,42 +952,44 @@ static int pblk_line_set_metadata(struct pblk *pblk, struct pblk_line *line,
 	}
 
 	/* Run-time metadata */
-	line->lun_bitmap = ((void *)(smeta)) + sizeof(struct line_smeta);
+	line->lun_bitmap = ((void *)(smeta_buf)) + sizeof(struct line_smeta);
 
 	/* Mark LUNs allocated in this line (all for now) */
 	bitmap_set(line->lun_bitmap, 0, lm->lun_bitmap_len);
 
-	smeta->header.identifier = cpu_to_le32(PBLK_MAGIC);
-	memcpy(smeta->header.uuid, pblk->instance_uuid, 16);
-	smeta->header.id = cpu_to_le32(line->id);
-	smeta->header.type = cpu_to_le16(line->type);
-	smeta->header.version = cpu_to_le16(1);
+	smeta_buf->header.identifier = cpu_to_le32(PBLK_MAGIC);
+	memcpy(smeta_buf->header.uuid, pblk->instance_uuid, 16);
+	smeta_buf->header.id = cpu_to_le32(line->id);
+	smeta_buf->header.type = cpu_to_le16(line->type);
+	smeta_buf->header.version = cpu_to_le16(1);
 
 	/* Start metadata */
-	smeta->seq_nr = cpu_to_le64(line->seq_nr);
-	smeta->window_wr_lun = cpu_to_le32(geo->nr_luns);
+	smeta_buf->seq_nr = cpu_to_le64(line->seq_nr);
+	smeta_buf->window_wr_lun = cpu_to_le32(geo->nr_luns);
 
 	/* Fill metadata among lines */
 	if (cur) {
 		memcpy(line->lun_bitmap, cur->lun_bitmap, lm->lun_bitmap_len);
-		smeta->prev_id = cpu_to_le32(cur->id);
-		cur->emeta->next_id = cpu_to_le32(line->id);
+		smeta_buf->prev_id = cpu_to_le32(cur->id);
+		cur->emeta->buf->next_id = cpu_to_le32(line->id);
 	} else {
-		smeta->prev_id = cpu_to_le32(PBLK_LINE_EMPTY);
+		smeta_buf->prev_id = cpu_to_le32(PBLK_LINE_EMPTY);
 	}
 
 	/* All smeta must be set at this point */
-	smeta->header.crc = cpu_to_le32(pblk_calc_meta_header_crc(pblk, smeta));
-	smeta->crc = cpu_to_le32(pblk_calc_smeta_crc(pblk, smeta));
+	smeta_buf->header.crc = cpu_to_le32(
+			pblk_calc_meta_header_crc(pblk, &smeta_buf->header));
+	smeta_buf->crc = cpu_to_le32(pblk_calc_smeta_crc(pblk, smeta_buf));
 
 	/* End metadata */
-	memcpy(&emeta->header, &smeta->header, sizeof(struct line_header));
-	emeta->seq_nr = cpu_to_le64(line->seq_nr);
-	emeta->nr_lbas = cpu_to_le64(line->sec_in_line);
-	emeta->nr_valid_lbas = cpu_to_le64(0);
-	emeta->next_id = cpu_to_le32(PBLK_LINE_EMPTY);
-	emeta->crc = cpu_to_le32(0);
-	emeta->prev_id = smeta->prev_id;
+	memcpy(&emeta_buf->header, &smeta_buf->header,
+						sizeof(struct line_header));
+	emeta_buf->seq_nr = cpu_to_le64(line->seq_nr);
+	emeta_buf->nr_lbas = cpu_to_le64(line->sec_in_line);
+	emeta_buf->nr_valid_lbas = cpu_to_le64(0);
+	emeta_buf->next_id = cpu_to_le32(PBLK_LINE_EMPTY);
+	emeta_buf->crc = cpu_to_le32(0);
+	emeta_buf->prev_id = smeta_buf->prev_id;
 
 	return 1;
 }
@@ -987,8 +1044,8 @@ static int pblk_line_init_bb(struct pblk *pblk, struct pblk_line *line,
 	 * blocks to make sure that there are enough sectors to store emeta
 	 */
 	bit = lm->sec_per_line;
-	off = lm->sec_per_line - lm->emeta_sec;
-	bitmap_set(line->invalid_bitmap, off, lm->emeta_sec);
+	off = lm->sec_per_line - lm->emeta_sec[0];
+	bitmap_set(line->invalid_bitmap, off, lm->emeta_sec[0]);
 	while (nr_bb) {
 		off -= geo->sec_per_pl;
 		if (!test_bit(off, line->invalid_bitmap)) {
@@ -997,9 +1054,11 @@ static int pblk_line_init_bb(struct pblk *pblk, struct pblk_line *line,
 		}
 	}
 
-	line->sec_in_line -= lm->emeta_sec;
+	line->sec_in_line -= lm->emeta_sec[0];
 	line->emeta_ssec = off;
-	line->vsc = line->left_ssecs = line->left_msecs = line->sec_in_line;
+	line->nr_valid_lbas = 0;
+	line->left_ssecs = line->left_msecs = line->sec_in_line;
+	*line->vsc = cpu_to_le32(line->sec_in_line);
 
 	if (lm->sec_per_line - line->sec_in_line !=
 		bitmap_weight(line->invalid_bitmap, lm->sec_per_line)) {
@@ -1046,6 +1105,8 @@ static int pblk_line_prepare(struct pblk *pblk, struct pblk_line *line)
 
 	atomic_set(&line->left_eblks, blk_in_line);
 	atomic_set(&line->left_seblks, blk_in_line);
+
+	line->meta_distance = lm->meta_distance;
 	spin_unlock(&line->lock);
 
 	/* Bad blocks do not need to be erased */
@@ -1170,7 +1231,6 @@ struct pblk_line *pblk_line_get_first_data(struct pblk *pblk)
 {
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 	struct pblk_line *line;
-	int meta_line;
 	int is_next = 0;
 
 	spin_lock(&l_mg->free_lock);
@@ -1184,11 +1244,7 @@ struct pblk_line *pblk_line_get_first_data(struct pblk *pblk)
 	line->type = PBLK_LINETYPE_DATA;
 	l_mg->data_line = line;
 
-	meta_line = find_first_zero_bit(&l_mg->meta_bitmap, PBLK_DATA_LINES);
-	set_bit(meta_line, &l_mg->meta_bitmap);
-	line->smeta = l_mg->sline_meta[meta_line].meta;
-	line->emeta = l_mg->eline_meta[meta_line].meta;
-	line->meta_line = meta_line;
+	pblk_line_setup_metadata(line, l_mg, &pblk->lm);
 
 	/* Allocate next line for preparation */
 	l_mg->data_next = pblk_line_get(pblk);
@@ -1207,7 +1263,7 @@ struct pblk_line *pblk_line_get_first_data(struct pblk *pblk)
 		return NULL;
 
 retry_setup:
-	if (!pblk_line_set_metadata(pblk, line, NULL)) {
+	if (!pblk_line_init_metadata(pblk, line, NULL)) {
 		line = pblk_line_retry(pblk, line);
 		if (!line)
 			return NULL;
@@ -1228,11 +1284,9 @@ struct pblk_line *pblk_line_get_first_data(struct pblk *pblk)
 
 struct pblk_line *pblk_line_replace_data(struct pblk *pblk)
 {
-	struct pblk_line_meta *lm = &pblk->lm;
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 	struct pblk_line *cur, *new;
 	unsigned int left_seblks;
-	int meta_line;
 	int is_next = 0;
 
 	cur = l_mg->data_line;
@@ -1263,29 +1317,14 @@ struct pblk_line *pblk_line_replace_data(struct pblk *pblk)
 		is_next = 1;
 	}
 
-retry_meta:
-	meta_line = find_first_zero_bit(&l_mg->meta_bitmap, PBLK_DATA_LINES);
-	if (meta_line == PBLK_DATA_LINES) {
-		spin_unlock(&l_mg->free_lock);
-		io_schedule();
-		spin_lock(&l_mg->free_lock);
-		goto retry_meta;
-	}
-
-	set_bit(meta_line, &l_mg->meta_bitmap);
-	new->smeta = l_mg->sline_meta[meta_line].meta;
-	new->emeta = l_mg->eline_meta[meta_line].meta;
-	new->meta_line = meta_line;
-
-	memset(new->smeta, 0, lm->smeta_len);
-	memset(new->emeta, 0, lm->emeta_len);
+	pblk_line_setup_metadata(new, l_mg, &pblk->lm);
 	spin_unlock(&l_mg->free_lock);
 
 	if (is_next)
 		pblk_rl_free_lines_dec(&pblk->rl, l_mg->data_next);
 
 retry_setup:
-	if (!pblk_line_set_metadata(pblk, new, cur)) {
+	if (!pblk_line_init_metadata(pblk, new, cur)) {
 		new = pblk_line_retry(pblk, new);
 		if (!new)
 			return NULL;
@@ -1311,6 +1350,8 @@ void pblk_line_free(struct pblk *pblk, struct pblk_line *line)
 	if (line->invalid_bitmap)
 		mempool_free(line->invalid_bitmap, pblk->line_meta_pool);
 
+	*line->vsc = cpu_to_le32(EMPTY_ENTRY);
+
 	line->map_bitmap = NULL;
 	line->invalid_bitmap = NULL;
 	line->smeta = NULL;
@@ -1386,14 +1427,10 @@ int pblk_line_is_full(struct pblk_line *line)
 void pblk_line_close(struct pblk *pblk, struct pblk_line *line)
 {
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line_meta *lm = &pblk->lm;
 	struct list_head *move_list;
 
-	line->emeta->crc = cpu_to_le32(pblk_calc_emeta_crc(pblk, line->emeta));
-
-	if (pblk_line_submit_emeta_io(pblk, line, line->cur_sec, WRITE))
-		pr_err("pblk: line %d close I/O failed\n", line->id);
-
-	WARN(!bitmap_full(line->map_bitmap, line->sec_in_line),
+	WARN(!bitmap_full(line->map_bitmap, lm->sec_per_line),
 				"pblk: corrupt closed line %d\n", line->id);
 
 	spin_lock(&l_mg->free_lock);
@@ -1417,6 +1454,27 @@ void pblk_line_close(struct pblk *pblk, struct pblk_line *line)
 	spin_unlock(&l_mg->gc_lock);
 }
 
+void pblk_line_close_meta(struct pblk *pblk, struct pblk_line *line)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_emeta *emeta = line->emeta;
+	struct line_emeta *emeta_buf = emeta->buf;
+
+	/* No need for exact vsc value; avoid a big line lock and tak aprox. */
+	memcpy(emeta_to_vsc(pblk, emeta_buf), l_mg->vsc_list, lm->vsc_list_len);
+	memcpy(emeta_to_bb(emeta_buf), line->blk_bitmap, lm->blk_bitmap_len);
+
+	emeta_buf->nr_valid_lbas = cpu_to_le64(line->nr_valid_lbas);
+	emeta_buf->crc = cpu_to_le32(pblk_calc_emeta_crc(pblk, emeta_buf));
+
+	spin_lock(&l_mg->close_lock);
+	spin_lock(&line->lock);
+	list_add_tail(&line->list, &l_mg->emeta_list);
+	spin_unlock(&line->lock);
+	spin_unlock(&l_mg->close_lock);
+}
+
 void pblk_line_close_ws(struct work_struct *work)
 {
 	struct pblk_line_ws *line_ws = container_of(work, struct pblk_line_ws,
@@ -1476,7 +1534,7 @@ void pblk_down_rq(struct pblk *pblk, struct ppa_addr *ppa_list, int nr_ppas,
 	struct nvm_tgt_dev *dev = pblk->dev;
 	struct nvm_geo *geo = &dev->geo;
 	struct pblk_lun *rlun;
-	int lun_id = ppa_list[0].g.ch * geo->luns_per_chnl + ppa_list[0].g.lun;
+	int pos = pblk_ppa_to_pos(geo, ppa_list[0]);
 	int ret;
 
 	/*
@@ -1493,10 +1551,10 @@ void pblk_down_rq(struct pblk *pblk, struct ppa_addr *ppa_list, int nr_ppas,
 	/* If the LUN has been locked for this same request, do no attempt to
 	 * lock it again
 	 */
-	if (test_and_set_bit(lun_id, lun_bitmap))
+	if (test_and_set_bit(pos, lun_bitmap))
 		return;
 
-	rlun = &pblk->luns[lun_id];
+	rlun = &pblk->luns[pos];
 	ret = down_timeout(&rlun->wr_sem, msecs_to_jiffies(5000));
 	if (ret) {
 		switch (ret) {
diff --git a/drivers/lightnvm/pblk-gc.c b/drivers/lightnvm/pblk-gc.c
index eaf479c6b63c..2e7fb7a51854 100644
--- a/drivers/lightnvm/pblk-gc.c
+++ b/drivers/lightnvm/pblk-gc.c
@@ -156,7 +156,8 @@ static void pblk_gc_line_ws(struct work_struct *work)
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 	struct pblk_line *line = line_ws->line;
 	struct pblk_line_meta *lm = &pblk->lm;
-	__le64 *lba_list = line_ws->priv;
+	struct line_emeta *emeta_buf = line_ws->priv;
+	__le64 *lba_list;
 	u64 *gc_list;
 	int sec_left;
 	int nr_ppas, bit;
@@ -164,8 +165,18 @@ static void pblk_gc_line_ws(struct work_struct *work)
 
 	pr_debug("pblk: line '%d' being reclaimed for GC\n", line->id);
 
+	/* If this read fails, it means that emeta is corrupted. For now, leave
+	 * the line untouched. TODO: Implement a recovery routine that scans and
+	 * moves all sectors on the line.
+	 */
+	lba_list = pblk_recov_get_lba_list(pblk, emeta_buf);
+	if (!lba_list) {
+		pr_err("pblk: could not interpret emeta (line %d)\n", line->id);
+		goto out;
+	}
+
 	spin_lock(&line->lock);
-	sec_left = line->vsc;
+	sec_left = le32_to_cpu(*line->vsc);
 	if (!sec_left) {
 		/* Lines are erased before being used (l_mg->data_/log_next) */
 		spin_unlock(&line->lock);
@@ -206,7 +217,7 @@ static void pblk_gc_line_ws(struct work_struct *work)
 
 	if (pblk_gc_move_valid_secs(pblk, line, gc_list, nr_ppas)) {
 		pr_err("pblk: could not GC all sectors: line:%d (%d/%d/%d)\n",
-						line->id, line->vsc,
+						line->id, *line->vsc,
 						nr_ppas, nr_ppas);
 		put_line = 0;
 		pblk_put_line_back(pblk, line);
@@ -218,7 +229,7 @@ static void pblk_gc_line_ws(struct work_struct *work)
 		goto next_rq;
 
 out:
-	pblk_mfree(line->emeta, l_mg->emeta_alloc_type);
+	pblk_mfree(emeta_buf, l_mg->emeta_alloc_type);
 	mempool_free(line_ws, pblk->line_ws_pool);
 	atomic_dec(&pblk->gc.inflight_gc);
 	if (put_line)
@@ -229,37 +240,27 @@ static int pblk_gc_line(struct pblk *pblk, struct pblk_line *line)
 {
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 	struct pblk_line_meta *lm = &pblk->lm;
+	struct line_emeta *emeta_buf;
 	struct pblk_line_ws *line_ws;
-	__le64 *lba_list;
 	int ret;
 
 	line_ws = mempool_alloc(pblk->line_ws_pool, GFP_KERNEL);
-	line->emeta = pblk_malloc(lm->emeta_len, l_mg->emeta_alloc_type,
+	emeta_buf = pblk_malloc(lm->emeta_len[0], l_mg->emeta_alloc_type,
 								GFP_KERNEL);
-	if (!line->emeta) {
+	if (!emeta_buf) {
 		pr_err("pblk: cannot use GC emeta\n");
 		goto fail_free_ws;
 	}
 
-	ret = pblk_line_read_emeta(pblk, line);
+	ret = pblk_line_read_emeta(pblk, line, emeta_buf);
 	if (ret) {
 		pr_err("pblk: line %d read emeta failed (%d)\n", line->id, ret);
 		goto fail_free_emeta;
 	}
 
-	/* If this read fails, it means that emeta is corrupted. For now, leave
-	 * the line untouched. TODO: Implement a recovery routine that scans and
-	 * moves all sectors on the line.
-	 */
-	lba_list = pblk_recov_get_lba_list(pblk, line->emeta);
-	if (!lba_list) {
-		pr_err("pblk: could not interpret emeta (line %d)\n", line->id);
-		goto fail_free_emeta;
-	}
-
 	line_ws->pblk = pblk;
 	line_ws->line = line;
-	line_ws->priv = lba_list;
+	line_ws->priv = emeta_buf;
 
 	INIT_WORK(&line_ws->ws, pblk_gc_line_ws);
 	queue_work(pblk->gc.gc_reader_wq, &line_ws->ws);
@@ -267,7 +268,7 @@ static int pblk_gc_line(struct pblk *pblk, struct pblk_line *line)
 	return 0;
 
 fail_free_emeta:
-	pblk_mfree(line->emeta, l_mg->emeta_alloc_type);
+	pblk_mfree(emeta_buf, l_mg->emeta_alloc_type);
 fail_free_ws:
 	mempool_free(line_ws, pblk->line_ws_pool);
 	pblk_put_line_back(pblk, line);
diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
index 51dd42c7e852..e51b965ae6a9 100644
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -239,29 +239,10 @@ static int pblk_core_init(struct pblk *pblk)
 {
 	struct nvm_tgt_dev *dev = pblk->dev;
 	struct nvm_geo *geo = &dev->geo;
-	int max_write_ppas;
-	int mod;
 
-	pblk->min_write_pgs = geo->sec_per_pl * (geo->sec_size / PAGE_SIZE);
-	max_write_ppas = pblk->min_write_pgs * geo->nr_luns;
-	pblk->max_write_pgs = (max_write_ppas < nvm_max_phys_sects(dev)) ?
-				max_write_ppas : nvm_max_phys_sects(dev);
 	pblk->pgs_in_buffer = NVM_MEM_PAGE_WRITE * geo->sec_per_pg *
 						geo->nr_planes * geo->nr_luns;
 
-	pblk_set_sec_per_write(pblk, pblk->min_write_pgs);
-
-	if (pblk->max_write_pgs > PBLK_MAX_REQ_ADDRS) {
-		pr_err("pblk: cannot support device max_phys_sect\n");
-		return -EINVAL;
-	}
-
-	div_u64_rem(geo->sec_per_blk, pblk->min_write_pgs, &mod);
-	if (mod) {
-		pr_err("pblk: bad configuration of sectors/pages\n");
-		return -EINVAL;
-	}
-
 	if (pblk_init_global_caches(pblk))
 		return -ENOMEM;
 
@@ -370,10 +351,12 @@ static void pblk_line_meta_free(struct pblk *pblk)
 
 	kfree(l_mg->bb_template);
 	kfree(l_mg->bb_aux);
+	kfree(l_mg->vsc_list);
 
 	for (i = 0; i < PBLK_DATA_LINES; i++) {
-		pblk_mfree(l_mg->sline_meta[i].meta, l_mg->smeta_alloc_type);
-		pblk_mfree(l_mg->eline_meta[i].meta, l_mg->emeta_alloc_type);
+		pblk_mfree(&l_mg->sline_meta[i], l_mg->smeta_alloc_type);
+		pblk_mfree(l_mg->eline_meta[i]->buf, l_mg->emeta_alloc_type);
+		kfree(&l_mg->eline_meta[i]);
 	}
 
 	kfree(pblk->lines);
@@ -413,7 +396,8 @@ static int pblk_bb_discovery(struct nvm_tgt_dev *dev, struct pblk_lun *rlun)
 	return ret;
 }
 
-static int pblk_bb_line(struct pblk *pblk, struct pblk_line *line)
+static int pblk_bb_line(struct pblk *pblk, struct nvm_geo *geo,
+			struct pblk_line *line)
 {
 	struct pblk_line_meta *lm = &pblk->lm;
 	struct pblk_lun *rlun;
@@ -435,7 +419,7 @@ static int pblk_bb_line(struct pblk *pblk, struct pblk_line *line)
 		if (rlun->bb_list[line->id] == NVM_BLK_T_FREE)
 			continue;
 
-		set_bit(i, line->blk_bitmap);
+		set_bit(pblk_ppa_to_pos(geo, rlun->bppa), line->blk_bitmap);
 		bb_cnt++;
 	}
 
@@ -507,12 +491,32 @@ static int pblk_lines_configure(struct pblk *pblk, int flags)
 }
 
 /* See comment over struct line_emeta definition */
-static unsigned int calc_emeta_len(struct pblk *pblk, struct pblk_line_meta *lm)
+static unsigned int calc_emeta_len(struct pblk *pblk)
 {
-	return (sizeof(struct line_emeta) +
-			((lm->sec_per_line - lm->emeta_sec) * sizeof(u64)) +
-			(pblk->l_mg.nr_lines * sizeof(u32)) +
-			lm->blk_bitmap_len);
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+
+	/* Round to sector size so that lba_list starts on its own sector */
+	lm->emeta_sec[1] = DIV_ROUND_UP(
+			sizeof(struct line_emeta) + lm->blk_bitmap_len,
+			geo->sec_size);
+	lm->emeta_len[1] = lm->emeta_sec[1] * geo->sec_size;
+
+	/* Round to sector size so that vsc_list starts on its own sector */
+	lm->dsec_per_line = lm->sec_per_line - lm->emeta_sec[0];
+	lm->emeta_sec[2] = DIV_ROUND_UP(lm->dsec_per_line * sizeof(u64),
+			geo->sec_size);
+	lm->emeta_len[2] = lm->emeta_sec[2] * geo->sec_size;
+
+	lm->emeta_sec[3] = DIV_ROUND_UP(l_mg->nr_lines * sizeof(u32),
+			geo->sec_size);
+	lm->emeta_len[3] = lm->emeta_sec[3] * geo->sec_size;
+
+	lm->vsc_list_len = l_mg->nr_lines * sizeof(u32);
+
+	return (lm->emeta_len[1] + lm->emeta_len[2] + lm->emeta_len[3]);
 }
 
 static void pblk_set_provision(struct pblk *pblk, long nr_free_blks)
@@ -536,6 +540,79 @@ static void pblk_set_provision(struct pblk *pblk, long nr_free_blks)
 	atomic_set(&pblk->rl.free_blocks, nr_free_blks);
 }
 
+static int pblk_lines_alloc_metadata(struct pblk *pblk)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line_meta *lm = &pblk->lm;
+	int i;
+
+	/* smeta is always small enough to fit on a kmalloc memory allocation,
+	 * emeta depends on the number of LUNs allocated to the pblk instance
+	 */
+	l_mg->smeta_alloc_type = PBLK_KMALLOC_META;
+	for (i = 0; i < PBLK_DATA_LINES; i++) {
+		l_mg->sline_meta[i] = kmalloc(lm->smeta_len, GFP_KERNEL);
+		if (!l_mg->sline_meta[i])
+			goto fail_free_smeta;
+	}
+
+	/* emeta allocates three different buffers for managing metadata with
+	 * in-memory and in-media layouts
+	 */
+	for (i = 0; i < PBLK_DATA_LINES; i++) {
+		struct pblk_emeta *emeta;
+
+		emeta = kmalloc(sizeof(struct pblk_emeta), GFP_KERNEL);
+		if (!emeta)
+			goto fail_free_emeta;
+
+		if (lm->emeta_len[0] > KMALLOC_MAX_CACHE_SIZE) {
+			l_mg->emeta_alloc_type = PBLK_VMALLOC_META;
+
+			emeta->buf = vmalloc(lm->emeta_len[0]);
+			if (!emeta->buf) {
+				kfree(emeta);
+				goto fail_free_emeta;
+			}
+
+			emeta->nr_entries = lm->emeta_sec[0];
+			l_mg->eline_meta[i] = emeta;
+		} else {
+			l_mg->emeta_alloc_type = PBLK_KMALLOC_META;
+
+			emeta->buf = kmalloc(lm->emeta_len[0], GFP_KERNEL);
+			if (!emeta->buf) {
+				kfree(emeta);
+				goto fail_free_emeta;
+			}
+
+			emeta->nr_entries = lm->emeta_sec[0];
+			l_mg->eline_meta[i] = emeta;
+		}
+	}
+
+	l_mg->vsc_list = kcalloc(l_mg->nr_lines, sizeof(__le32), GFP_KERNEL);
+	if (!l_mg->vsc_list)
+		goto fail_free_emeta;
+
+	for (i = 0; i < l_mg->nr_lines; i++)
+		l_mg->vsc_list[i] = cpu_to_le32(EMPTY_ENTRY);
+
+	return 0;
+
+fail_free_emeta:
+	while (--i >= 0) {
+		vfree(l_mg->eline_meta[i]->buf);
+		kfree(&l_mg->eline_meta[i]);
+	}
+
+fail_free_smeta:
+	for (i = 0; i < PBLK_DATA_LINES; i++)
+		pblk_mfree(&l_mg->sline_meta[i], l_mg->smeta_alloc_type);
+
+	return -ENOMEM;
+}
+
 static int pblk_lines_init(struct pblk *pblk)
 {
 	struct nvm_tgt_dev *dev = pblk->dev;
@@ -545,9 +622,31 @@ static int pblk_lines_init(struct pblk *pblk)
 	struct pblk_line *line;
 	unsigned int smeta_len, emeta_len;
 	long nr_bad_blks, nr_free_blks;
-	int bb_distance;
-	int i;
-	int ret;
+	int bb_distance, max_write_ppas, mod;
+	int i, ret;
+
+	pblk->min_write_pgs = geo->sec_per_pl * (geo->sec_size / PAGE_SIZE);
+	max_write_ppas = pblk->min_write_pgs * geo->nr_luns;
+	pblk->max_write_pgs = (max_write_ppas < nvm_max_phys_sects(dev)) ?
+				max_write_ppas : nvm_max_phys_sects(dev);
+	pblk_set_sec_per_write(pblk, pblk->min_write_pgs);
+
+	if (pblk->max_write_pgs > PBLK_MAX_REQ_ADDRS) {
+		pr_err("pblk: cannot support device max_phys_sect\n");
+		return -EINVAL;
+	}
+
+	div_u64_rem(geo->sec_per_blk, pblk->min_write_pgs, &mod);
+	if (mod) {
+		pr_err("pblk: bad configuration of sectors/pages\n");
+		return -EINVAL;
+	}
+
+	l_mg->nr_lines = geo->blks_per_lun;
+	l_mg->log_line = l_mg->data_line = NULL;
+	l_mg->l_seq_nr = l_mg->d_seq_nr = 0;
+	l_mg->nr_free_lines = 0;
+	bitmap_zero(&l_mg->meta_bitmap, PBLK_DATA_LINES);
 
 	lm->sec_per_line = geo->sec_per_blk * geo->nr_luns;
 	lm->blk_per_line = geo->nr_luns;
@@ -556,20 +655,17 @@ static int pblk_lines_init(struct pblk *pblk)
 	lm->lun_bitmap_len = BITS_TO_LONGS(geo->nr_luns) * sizeof(long);
 	lm->high_thrs = lm->sec_per_line / 2;
 	lm->mid_thrs = lm->sec_per_line / 4;
+	lm->meta_distance = (geo->nr_luns / 2) * pblk->min_write_pgs;
 
 	/* Calculate necessary pages for smeta. See comment over struct
 	 * line_smeta definition
 	 */
-	lm->smeta_len = sizeof(struct line_smeta) +
-				PBLK_LINE_NR_LUN_BITMAP * lm->lun_bitmap_len;
-
 	i = 1;
 add_smeta_page:
 	lm->smeta_sec = i * geo->sec_per_pl;
 	lm->smeta_len = lm->smeta_sec * geo->sec_size;
 
-	smeta_len = sizeof(struct line_smeta) +
-				PBLK_LINE_NR_LUN_BITMAP * lm->lun_bitmap_len;
+	smeta_len = sizeof(struct line_smeta) + lm->lun_bitmap_len;
 	if (smeta_len > lm->smeta_len) {
 		i++;
 		goto add_smeta_page;
@@ -580,65 +676,22 @@ static int pblk_lines_init(struct pblk *pblk)
 	 */
 	i = 1;
 add_emeta_page:
-	lm->emeta_sec = i * geo->sec_per_pl;
-	lm->emeta_len = lm->emeta_sec * geo->sec_size;
+	lm->emeta_sec[0] = i * geo->sec_per_pl;
+	lm->emeta_len[0] = lm->emeta_sec[0] * geo->sec_size;
 
-	emeta_len = calc_emeta_len(pblk, lm);
-	if (emeta_len > lm->emeta_len) {
+	emeta_len = calc_emeta_len(pblk);
+	if (emeta_len > lm->emeta_len[0]) {
 		i++;
 		goto add_emeta_page;
 	}
+
 	lm->emeta_bb = geo->nr_luns - i;
-
-	lm->min_blk_line = 1 + DIV_ROUND_UP(lm->smeta_sec + lm->emeta_sec,
+	lm->min_blk_line = 1 + DIV_ROUND_UP(lm->smeta_sec + lm->emeta_sec[0],
 							geo->sec_per_blk);
 
-	l_mg->nr_lines = geo->blks_per_lun;
-	l_mg->log_line = l_mg->data_line = NULL;
-	l_mg->l_seq_nr = l_mg->d_seq_nr = 0;
-	l_mg->nr_free_lines = 0;
-	bitmap_zero(&l_mg->meta_bitmap, PBLK_DATA_LINES);
-
-	/* smeta is always small enough to fit on a kmalloc memory allocation,
-	 * emeta depends on the number of LUNs allocated to the pblk instance
-	 */
-	l_mg->smeta_alloc_type = PBLK_KMALLOC_META;
-	for (i = 0; i < PBLK_DATA_LINES; i++) {
-		l_mg->sline_meta[i].meta = kmalloc(lm->smeta_len, GFP_KERNEL);
-		if (!l_mg->sline_meta[i].meta)
-			while (--i >= 0) {
-				kfree(l_mg->sline_meta[i].meta);
-				ret = -ENOMEM;
-				goto fail;
-			}
-	}
-
-	if (lm->emeta_len > KMALLOC_MAX_CACHE_SIZE) {
-		l_mg->emeta_alloc_type = PBLK_VMALLOC_META;
-
-		for (i = 0; i < PBLK_DATA_LINES; i++) {
-			l_mg->eline_meta[i].meta = vmalloc(lm->emeta_len);
-			if (!l_mg->eline_meta[i].meta)
-				while (--i >= 0) {
-					vfree(l_mg->eline_meta[i].meta);
-					ret = -ENOMEM;
-					goto fail;
-				}
-		}
-	} else {
-		l_mg->emeta_alloc_type = PBLK_KMALLOC_META;
-
-		for (i = 0; i < PBLK_DATA_LINES; i++) {
-			l_mg->eline_meta[i].meta =
-					kmalloc(lm->emeta_len, GFP_KERNEL);
-			if (!l_mg->eline_meta[i].meta)
-				while (--i >= 0) {
-					kfree(l_mg->eline_meta[i].meta);
-					ret = -ENOMEM;
-					goto fail;
-				}
-		}
-	}
+	ret = pblk_lines_alloc_metadata(pblk);
+	if (ret)
+		goto fail;
 
 	l_mg->bb_template = kzalloc(lm->sec_bitmap_len, GFP_KERNEL);
 	if (!l_mg->bb_template) {
@@ -665,11 +718,14 @@ static int pblk_lines_init(struct pblk *pblk)
 	INIT_LIST_HEAD(&l_mg->gc_low_list);
 	INIT_LIST_HEAD(&l_mg->gc_empty_list);
 
+	INIT_LIST_HEAD(&l_mg->emeta_list);
+
 	l_mg->gc_lists[0] = &l_mg->gc_high_list;
 	l_mg->gc_lists[1] = &l_mg->gc_mid_list;
 	l_mg->gc_lists[2] = &l_mg->gc_low_list;
 
 	spin_lock_init(&l_mg->free_lock);
+	spin_lock_init(&l_mg->close_lock);
 	spin_lock_init(&l_mg->gc_lock);
 
 	pblk->lines = kcalloc(l_mg->nr_lines, sizeof(struct pblk_line),
@@ -690,9 +746,10 @@ static int pblk_lines_init(struct pblk *pblk)
 		line->type = PBLK_LINETYPE_FREE;
 		line->state = PBLK_LINESTATE_FREE;
 		line->gc_group = PBLK_LINEGC_NONE;
+		line->vsc = &l_mg->vsc_list[i];
 		spin_lock_init(&line->lock);
 
-		nr_bad_blks = pblk_bb_line(pblk, line);
+		nr_bad_blks = pblk_bb_line(pblk, geo, line);
 		if (nr_bad_blks < 0 || nr_bad_blks > lm->blk_per_line) {
 			ret = -EINVAL;
 			goto fail_free_lines;
@@ -726,10 +783,7 @@ static int pblk_lines_init(struct pblk *pblk)
 fail_free_bb_template:
 	kfree(l_mg->bb_template);
 fail_free_meta:
-	for (i = 0; i < PBLK_DATA_LINES; i++) {
-		pblk_mfree(l_mg->sline_meta[i].meta, l_mg->smeta_alloc_type);
-		pblk_mfree(l_mg->eline_meta[i].meta, l_mg->emeta_alloc_type);
-	}
+	pblk_line_meta_free(pblk);
 fail:
 	for (i = 0; i < geo->nr_luns; i++)
 		kfree(pblk->luns[i].bb_list);
diff --git a/drivers/lightnvm/pblk-map.c b/drivers/lightnvm/pblk-map.c
index 84309bd400d5..08580a649499 100644
--- a/drivers/lightnvm/pblk-map.c
+++ b/drivers/lightnvm/pblk-map.c
@@ -25,9 +25,9 @@ static void pblk_map_page_data(struct pblk *pblk, unsigned int sentry,
 			       unsigned int valid_secs)
 {
 	struct pblk_line *line = pblk_line_get_data(pblk);
-	struct line_emeta *emeta = line->emeta;
+	struct pblk_emeta *emeta = line->emeta;
 	struct pblk_w_ctx *w_ctx;
-	__le64 *lba_list = pblk_line_emeta_to_lbas(emeta);
+	__le64 *lba_list = emeta_to_lbas(pblk, emeta->buf);
 	u64 paddr;
 	int nr_secs = pblk->min_write_pgs;
 	int i;
@@ -51,7 +51,7 @@ static void pblk_map_page_data(struct pblk *pblk, unsigned int sentry,
 			w_ctx->ppa = ppa_list[i];
 			meta_list[i].lba = cpu_to_le64(w_ctx->lba);
 			lba_list[paddr] = cpu_to_le64(w_ctx->lba);
-			le64_add_cpu(&line->emeta->nr_valid_lbas, 1);
+			line->nr_valid_lbas++;
 		} else {
 			u64 addr_empty = cpu_to_le64(ADDR_EMPTY);
 
@@ -61,9 +61,11 @@ static void pblk_map_page_data(struct pblk *pblk, unsigned int sentry,
 	}
 
 	if (pblk_line_is_full(line)) {
+		struct pblk_line *prev_line = line;
 		line = pblk_line_replace_data(pblk);
 		if (!line)
 			return;
+		pblk_line_close_meta(pblk, prev_line);
 	}
 
 	pblk_down_rq(pblk, ppa_list, nr_secs, lun_bitmap);
@@ -104,11 +106,10 @@ void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
 		pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
 					lun_bitmap, &meta_list[i], map_secs);
 
-		erase_lun = rqd->ppa_list[i].g.lun * geo->nr_chnls +
-							rqd->ppa_list[i].g.ch;
-
 		/* line can change after page map */
 		e_line = pblk_line_get_erase(pblk);
+		erase_lun = pblk_ppa_to_pos(geo, rqd->ppa_list[i]);
+
 		spin_lock(&e_line->lock);
 		if (!test_bit(erase_lun, e_line->erase_bitmap)) {
 			set_bit(erase_lun, e_line->erase_bitmap);
diff --git a/drivers/lightnvm/pblk-recovery.c b/drivers/lightnvm/pblk-recovery.c
index 84671b44bddb..ba02d0bc3e45 100644
--- a/drivers/lightnvm/pblk-recovery.c
+++ b/drivers/lightnvm/pblk-recovery.c
@@ -120,18 +120,18 @@ int pblk_recov_setup_rq(struct pblk *pblk, struct pblk_c_ctx *c_ctx,
 	return 0;
 }
 
-__le64 *pblk_recov_get_lba_list(struct pblk *pblk, struct line_emeta *emeta)
+__le64 *pblk_recov_get_lba_list(struct pblk *pblk, struct line_emeta *emeta_buf)
 {
 	u32 crc;
 
-	crc = pblk_calc_emeta_crc(pblk, emeta);
-	if (le32_to_cpu(emeta->crc) != crc)
+	crc = pblk_calc_emeta_crc(pblk, emeta_buf);
+	if (le32_to_cpu(emeta_buf->crc) != crc)
 		return NULL;
 
-	if (le32_to_cpu(emeta->header.identifier) != PBLK_MAGIC)
+	if (le32_to_cpu(emeta_buf->header.identifier) != PBLK_MAGIC)
 		return NULL;
 
-	return pblk_line_emeta_to_lbas(emeta);
+	return emeta_to_lbas(pblk, emeta_buf);
 }
 
 static int pblk_recov_l2p_from_emeta(struct pblk *pblk, struct pblk_line *line)
@@ -139,19 +139,20 @@ static int pblk_recov_l2p_from_emeta(struct pblk *pblk, struct pblk_line *line)
 	struct nvm_tgt_dev *dev = pblk->dev;
 	struct nvm_geo *geo = &dev->geo;
 	struct pblk_line_meta *lm = &pblk->lm;
-	struct line_emeta *emeta = line->emeta;
+	struct pblk_emeta *emeta = line->emeta;
+	struct line_emeta *emeta_buf = emeta->buf;
 	__le64 *lba_list;
 	int data_start;
 	int nr_data_lbas, nr_valid_lbas, nr_lbas = 0;
 	int i;
 
-	lba_list = pblk_recov_get_lba_list(pblk, emeta);
+	lba_list = pblk_recov_get_lba_list(pblk, emeta_buf);
 	if (!lba_list)
 		return 1;
 
 	data_start = pblk_line_smeta_start(pblk, line) + lm->smeta_sec;
-	nr_data_lbas = lm->sec_per_line - lm->emeta_sec;
-	nr_valid_lbas = le64_to_cpu(emeta->nr_valid_lbas);
+	nr_data_lbas = lm->sec_per_line - lm->emeta_sec[0];
+	nr_valid_lbas = le64_to_cpu(emeta_buf->nr_valid_lbas);
 
 	for (i = data_start; i < nr_data_lbas && nr_lbas < nr_valid_lbas; i++) {
 		struct ppa_addr ppa;
@@ -169,7 +170,7 @@ static int pblk_recov_l2p_from_emeta(struct pblk *pblk, struct pblk_line *line)
 			if (test_and_set_bit(i, line->invalid_bitmap))
 				WARN_ONCE(1, "pblk: rec. double invalidate:\n");
 			else
-				line->vsc--;
+				le32_add_cpu(line->vsc, -1);
 			spin_unlock(&line->lock);
 
 			continue;
@@ -181,7 +182,7 @@ static int pblk_recov_l2p_from_emeta(struct pblk *pblk, struct pblk_line *line)
 
 	if (nr_valid_lbas != nr_lbas)
 		pr_err("pblk: line %d - inconsistent lba list(%llu/%d)\n",
-				line->id, line->emeta->nr_valid_lbas, nr_lbas);
+				line->id, emeta_buf->nr_valid_lbas, nr_lbas);
 
 	line->left_msecs = 0;
 
@@ -195,7 +196,7 @@ static int pblk_calc_sec_in_line(struct pblk *pblk, struct pblk_line *line)
 	struct pblk_line_meta *lm = &pblk->lm;
 	int nr_bb = bitmap_weight(line->blk_bitmap, lm->blk_per_line);
 
-	return lm->sec_per_line - lm->smeta_sec - lm->emeta_sec -
+	return lm->sec_per_line - lm->smeta_sec - lm->emeta_sec[0] -
 				nr_bb * geo->sec_per_blk;
 }
 
@@ -333,7 +334,7 @@ static int pblk_recov_pad_oob(struct pblk *pblk, struct pblk_line *line,
 	struct bio *bio;
 	void *data;
 	dma_addr_t dma_ppa_list, dma_meta_list;
-	__le64 *lba_list = pblk_line_emeta_to_lbas(line->emeta);
+	__le64 *lba_list = emeta_to_lbas(pblk, line->emeta->buf);
 	u64 w_ptr = line->cur_sec;
 	int left_line_ppas = line->left_msecs;
 	int rq_ppas, rq_len;
@@ -770,8 +771,9 @@ struct pblk_line *pblk_recov_l2p(struct pblk *pblk)
 	struct pblk_line_meta *lm = &pblk->lm;
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 	struct pblk_line *line, *tline, *data_line = NULL;
-	struct line_smeta *smeta;
-	struct line_emeta *emeta;
+	struct pblk_smeta *smeta;
+	struct pblk_emeta *emeta;
+	struct line_smeta *smeta_buf;
 	int found_lines = 0, recovered_lines = 0, open_lines = 0;
 	int is_next = 0;
 	int meta_line;
@@ -784,8 +786,9 @@ struct pblk_line *pblk_recov_l2p(struct pblk *pblk)
 	spin_lock(&l_mg->free_lock);
 	meta_line = find_first_zero_bit(&l_mg->meta_bitmap, PBLK_DATA_LINES);
 	set_bit(meta_line, &l_mg->meta_bitmap);
-	smeta = l_mg->sline_meta[meta_line].meta;
-	emeta = l_mg->eline_meta[meta_line].meta;
+	smeta = l_mg->sline_meta[meta_line];
+	emeta = l_mg->eline_meta[meta_line];
+	smeta_buf = smeta->buf;
 	spin_unlock(&l_mg->free_lock);
 
 	/* Order data lines using their sequence number */
@@ -796,33 +799,33 @@ struct pblk_line *pblk_recov_l2p(struct pblk *pblk)
 
 		memset(smeta, 0, lm->smeta_len);
 		line->smeta = smeta;
-		line->lun_bitmap = ((void *)(smeta)) +
+		line->lun_bitmap = ((void *)(smeta_buf)) +
 						sizeof(struct line_smeta);
 
 		/* Lines that cannot be read are assumed as not written here */
 		if (pblk_line_read_smeta(pblk, line))
 			continue;
 
-		crc = pblk_calc_smeta_crc(pblk, smeta);
-		if (le32_to_cpu(smeta->crc) != crc)
+		crc = pblk_calc_smeta_crc(pblk, smeta_buf);
+		if (le32_to_cpu(smeta_buf->crc) != crc)
 			continue;
 
-		if (le32_to_cpu(smeta->header.identifier) != PBLK_MAGIC)
+		if (le32_to_cpu(smeta_buf->header.identifier) != PBLK_MAGIC)
 			continue;
 
-		if (le16_to_cpu(smeta->header.version) != 1) {
+		if (le16_to_cpu(smeta_buf->header.version) != 1) {
 			pr_err("pblk: found incompatible line version %u\n",
-					smeta->header.version);
+					smeta_buf->header.version);
 			return ERR_PTR(-EINVAL);
 		}
 
 		/* The first valid instance uuid is used for initialization */
 		if (!valid_uuid) {
-			memcpy(pblk->instance_uuid, smeta->header.uuid, 16);
+			memcpy(pblk->instance_uuid, smeta_buf->header.uuid, 16);
 			valid_uuid = 1;
 		}
 
-		if (memcmp(pblk->instance_uuid, smeta->header.uuid, 16)) {
+		if (memcmp(pblk->instance_uuid, smeta_buf->header.uuid, 16)) {
 			pr_debug("pblk: ignore line %u due to uuid mismatch\n",
 					i);
 			continue;
@@ -830,9 +833,9 @@ struct pblk_line *pblk_recov_l2p(struct pblk *pblk)
 
 		/* Update line metadata */
 		spin_lock(&line->lock);
-		line->id = le32_to_cpu(line->smeta->header.id);
-		line->type = le16_to_cpu(line->smeta->header.type);
-		line->seq_nr = le64_to_cpu(line->smeta->seq_nr);
+		line->id = le32_to_cpu(smeta_buf->header.id);
+		line->type = le16_to_cpu(smeta_buf->header.type);
+		line->seq_nr = le64_to_cpu(smeta_buf->seq_nr);
 		spin_unlock(&line->lock);
 
 		/* Update general metadata */
@@ -848,7 +851,7 @@ struct pblk_line *pblk_recov_l2p(struct pblk *pblk)
 		pblk_recov_line_add_ordered(&recov_list, line);
 		found_lines++;
 		pr_debug("pblk: recovering data line %d, seq:%llu\n",
-						line->id, smeta->seq_nr);
+						line->id, smeta_buf->seq_nr);
 	}
 
 	if (!found_lines) {
@@ -868,15 +871,15 @@ struct pblk_line *pblk_recov_l2p(struct pblk *pblk)
 
 		recovered_lines++;
 		/* Calculate where emeta starts based on the line bb */
-		off = lm->sec_per_line - lm->emeta_sec;
+		off = lm->sec_per_line - lm->emeta_sec[0];
 		nr_bb = bitmap_weight(line->blk_bitmap, lm->blk_per_line);
 		off -= nr_bb * geo->sec_per_pl;
 
-		memset(emeta, 0, lm->emeta_len);
+		memset(&emeta->buf, 0, lm->emeta_len[0]);
 		line->emeta = emeta;
 		line->emeta_ssec = off;
 
-		if (pblk_line_read_emeta(pblk, line)) {
+		if (pblk_line_read_emeta(pblk, line, line->emeta->buf)) {
 			pblk_recov_l2p_from_oob(pblk, line);
 			goto next;
 		}
diff --git a/drivers/lightnvm/pblk-sysfs.c b/drivers/lightnvm/pblk-sysfs.c
index bf8fc6699299..707d1b91bde6 100644
--- a/drivers/lightnvm/pblk-sysfs.c
+++ b/drivers/lightnvm/pblk-sysfs.c
@@ -150,7 +150,7 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page)
 	ssize_t sz = 0;
 	int nr_free_lines;
 	int cur_data, cur_log;
-	int free_line_cnt = 0, closed_line_cnt = 0;
+	int free_line_cnt = 0, closed_line_cnt = 0, emeta_line_cnt = 0;
 	int d_line_cnt = 0, l_line_cnt = 0;
 	int gc_full = 0, gc_high = 0, gc_mid = 0, gc_low = 0, gc_empty = 0;
 	int free = 0, bad = 0, cor = 0;
@@ -166,6 +166,11 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page)
 		free_line_cnt++;
 	spin_unlock(&l_mg->free_lock);
 
+	spin_lock(&l_mg->close_lock);
+	list_for_each_entry(line, &l_mg->emeta_list, list)
+		emeta_line_cnt++;
+	spin_unlock(&l_mg->close_lock);
+
 	spin_lock(&l_mg->gc_lock);
 	list_for_each_entry(line, &l_mg->gc_full_list, list) {
 		if (line->type == PBLK_LINETYPE_DATA)
@@ -225,7 +230,7 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page)
 		cur_sec = l_mg->data_line->cur_sec;
 		msecs = l_mg->data_line->left_msecs;
 		ssecs = l_mg->data_line->left_ssecs;
-		vsc = l_mg->data_line->vsc;
+		vsc = le32_to_cpu(*l_mg->data_line->vsc);
 		sec_in_line = l_mg->data_line->sec_in_line;
 		meta_weight = bitmap_weight(&l_mg->meta_bitmap,
 							PBLK_DATA_LINES);
@@ -242,10 +247,11 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page)
 		geo->nr_luns, lm->blk_per_line, lm->sec_per_line);
 
 	sz += snprintf(page + sz, PAGE_SIZE - sz,
-		"lines:d:%d,l:%d-f:%d(%d),b:%d,co:%d,c:%d(d:%d,l:%d)t:%d\n",
+		"lines:d:%d,l:%d-f:%d(%d),m:%d,c:%d,b:%d,co:%d(d:%d,l:%d)t:%d\n",
 					cur_data, cur_log,
-					free, nr_free_lines, bad, cor,
+					free, nr_free_lines, emeta_line_cnt,
 					closed_line_cnt,
+					bad, cor,
 					d_line_cnt, l_line_cnt,
 					l_mg->nr_lines);
 
@@ -274,7 +280,7 @@ static ssize_t pblk_sysfs_lines_info(struct pblk *pblk, char *page)
 					lm->smeta_len, lm->smeta_sec);
 	sz += snprintf(page + sz, PAGE_SIZE - sz,
 				"emeta - len:%d, sec:%d, bb_start:%d\n",
-					lm->emeta_len, lm->emeta_sec,
+					lm->emeta_len[0], lm->emeta_sec[0],
 					lm->emeta_bb);
 	sz += snprintf(page + sz, PAGE_SIZE - sz,
 				"bitmap lengths: sec:%d, blk:%d, lun:%d\n",
diff --git a/drivers/lightnvm/pblk-write.c b/drivers/lightnvm/pblk-write.c
index c745a22057f8..1739c970692e 100644
--- a/drivers/lightnvm/pblk-write.c
+++ b/drivers/lightnvm/pblk-write.c
@@ -25,8 +25,6 @@ static void pblk_sync_line(struct pblk *pblk, struct pblk_line *line)
 
 	/* Counter protected by rb sync lock */
 	line->left_ssecs--;
-	if (!line->left_ssecs)
-		pblk_line_run_ws(pblk, line, NULL, pblk_line_close_ws);
 }
 
 static unsigned long pblk_end_w_bio(struct pblk *pblk, struct nvm_rq *rqd,
@@ -192,8 +190,40 @@ static void pblk_end_io_write(struct nvm_rq *rqd)
 	pblk_complete_write(pblk, rqd, c_ctx);
 }
 
+static void pblk_end_io_write_meta(struct nvm_rq *rqd)
+{
+	struct pblk *pblk = rqd->private;
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_g_ctx *m_ctx = nvm_rq_to_pdu(rqd);
+	struct pblk_line *line = m_ctx->private;
+	struct pblk_emeta *emeta = line->emeta;
+	int pos = pblk_ppa_to_pos(geo, rqd->ppa_list[0]);
+	struct pblk_lun *rlun = &pblk->luns[pos];
+	int sync;
+
+	up(&rlun->wr_sem);
+
+	if (rqd->error) {
+		pblk_log_write_err(pblk, rqd);
+		pr_err("pblk: metadata I/O failed\n");
+	}
+#ifdef CONFIG_NVM_DEBUG
+	else
+		WARN_ONCE(rqd->bio->bi_status, "pblk: corrupted write error\n");
+#endif
+
+	sync = atomic_add_return(rqd->nr_ppas, &emeta->sync);
+	if (sync == emeta->nr_entries)
+		pblk_line_run_ws(pblk, line, NULL, pblk_line_close_ws);
+
+	bio_put(rqd->bio);
+	pblk_free_rqd(pblk, rqd, READ);
+}
+
 static int pblk_alloc_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
-			   unsigned int nr_secs)
+			   unsigned int nr_secs,
+			   nvm_end_io_fn(*end_io))
 {
 	struct nvm_tgt_dev *dev = pblk->dev;
 
@@ -202,7 +232,7 @@ static int pblk_alloc_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
 	rqd->nr_ppas = nr_secs;
 	rqd->flags = pblk_set_progr_mode(pblk, WRITE);
 	rqd->private = pblk;
-	rqd->end_io = pblk_end_io_write;
+	rqd->end_io = end_io;
 
 	rqd->meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
 							&rqd->dma_meta_list);
@@ -234,7 +264,7 @@ static int pblk_setup_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
 		return -ENOMEM;
 	c_ctx->lun_bitmap = lun_bitmap;
 
-	ret = pblk_alloc_w_rq(pblk, rqd, nr_secs);
+	ret = pblk_alloc_w_rq(pblk, rqd, nr_secs, pblk_end_io_write);
 	if (ret) {
 		kfree(lun_bitmap);
 		return ret;
@@ -262,7 +292,7 @@ int pblk_setup_w_rec_rq(struct pblk *pblk, struct nvm_rq *rqd,
 
 	c_ctx->lun_bitmap = lun_bitmap;
 
-	ret = pblk_alloc_w_rq(pblk, rqd, rqd->nr_ppas);
+	ret = pblk_alloc_w_rq(pblk, rqd, rqd->nr_ppas, pblk_end_io_write);
 	if (ret)
 		return ret;
 
@@ -293,6 +323,166 @@ static int pblk_calc_secs_to_sync(struct pblk *pblk, unsigned int secs_avail,
 	return secs_to_sync;
 }
 
+static inline int pblk_valid_meta_ppa(struct pblk *pblk,
+				      struct pblk_line *meta_line,
+				      struct ppa_addr *ppa_list, int nr_ppas)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_line *data_line;
+	struct ppa_addr ppa, ppa_opt;
+	u64 paddr;
+	int i;
+
+	data_line = &pblk->lines[pblk_dev_ppa_to_line(ppa_list[0])];
+	paddr = pblk_lookup_page(pblk, meta_line);
+	ppa = addr_to_gen_ppa(pblk, paddr, 0);
+
+	if (test_bit(pblk_ppa_to_pos(geo, ppa), data_line->blk_bitmap))
+		return 1;
+
+	/* Schedule a metadata I/O that is half the distance from the data I/O
+	 * with regards to the number of LUNs forming the pblk instance. This
+	 * balances LUN conflicts across every I/O.
+	 *
+	 * When the LUN configuration changes (e.g., due to GC), this distance
+	 * can align, which would result on a LUN deadlock. In this case, modify
+	 * the distance to not be optimal, but allow metadata I/Os to succeed.
+	 */
+	ppa_opt = addr_to_gen_ppa(pblk, paddr + data_line->meta_distance, 0);
+	if (unlikely(ppa_opt.ppa == ppa.ppa)) {
+		data_line->meta_distance--;
+		return 0;
+	}
+
+	for (i = 0; i < nr_ppas; i += pblk->min_write_pgs)
+		if (ppa_list[i].g.ch == ppa_opt.g.ch &&
+					ppa_list[i].g.lun == ppa_opt.g.lun)
+			return 1;
+
+	if (test_bit(pblk_ppa_to_pos(geo, ppa_opt), data_line->blk_bitmap)) {
+		for (i = 0; i < nr_ppas; i += pblk->min_write_pgs)
+			if (ppa_list[i].g.ch == ppa.g.ch &&
+						ppa_list[i].g.lun == ppa.g.lun)
+				return 0;
+
+		return 1;
+	}
+
+	return 0;
+}
+
+int pblk_submit_meta_io(struct pblk *pblk, struct pblk_line *meta_line)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_emeta *emeta = meta_line->emeta;
+	struct pblk_g_ctx *m_ctx;
+	struct pblk_lun *rlun;
+	struct bio *bio;
+	struct nvm_rq *rqd;
+	void *data;
+	u64 paddr;
+	int rq_ppas = pblk->min_write_pgs;
+	int id = meta_line->id;
+	int rq_len;
+	int i, j;
+	int ret;
+
+	rqd = pblk_alloc_rqd(pblk, READ);
+	if (IS_ERR(rqd)) {
+		pr_err("pblk: cannot allocate write req.\n");
+		return PTR_ERR(rqd);
+	}
+	m_ctx = nvm_rq_to_pdu(rqd);
+	m_ctx->private = meta_line;
+
+	rq_len = rq_ppas * geo->sec_size;
+	data = ((void *)emeta->buf) + emeta->mem;
+
+	bio = pblk_bio_map_addr(pblk, data, rq_ppas, rq_len, GFP_KERNEL);
+	if (IS_ERR(bio)) {
+		ret = PTR_ERR(bio);
+		goto fail_free_rqd;
+	}
+	bio->bi_iter.bi_sector = 0; /* internal bio */
+	bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+	rqd->bio = bio;
+
+	ret = pblk_alloc_w_rq(pblk, rqd, rq_ppas, pblk_end_io_write_meta);
+	if (ret)
+		goto fail_free_bio;
+
+	for (i = 0; i < rqd->nr_ppas; ) {
+		spin_lock(&meta_line->lock);
+		paddr = __pblk_alloc_page(pblk, meta_line, rq_ppas);
+		spin_unlock(&meta_line->lock);
+		for (j = 0; j < rq_ppas; j++, i++, paddr++)
+			rqd->ppa_list[i] = addr_to_gen_ppa(pblk, paddr, id);
+	}
+
+	rlun = &pblk->luns[pblk_ppa_to_pos(geo, rqd->ppa_list[0])];
+	ret = down_timeout(&rlun->wr_sem, msecs_to_jiffies(5000));
+	if (ret) {
+		pr_err("pblk: lun semaphore timed out (%d)\n", ret);
+		goto fail_free_bio;
+	}
+
+	emeta->mem += rq_len;
+	if (emeta->mem >= lm->emeta_len[0]) {
+		spin_lock(&l_mg->close_lock);
+		list_del(&meta_line->list);
+		WARN(!bitmap_full(meta_line->map_bitmap, lm->sec_per_line),
+				"pblk: corrupt meta line %d\n", meta_line->id);
+		spin_unlock(&l_mg->close_lock);
+	}
+
+	ret = pblk_submit_io(pblk, rqd);
+	if (ret) {
+		pr_err("pblk: emeta I/O submission failed: %d\n", ret);
+		goto fail_rollback;
+	}
+
+	return NVM_IO_OK;
+
+fail_rollback:
+	spin_lock(&l_mg->close_lock);
+	pblk_dealloc_page(pblk, meta_line, rq_ppas);
+	list_add(&meta_line->list, &meta_line->list);
+	spin_unlock(&l_mg->close_lock);
+fail_free_bio:
+	bio_put(bio);
+fail_free_rqd:
+	pblk_free_rqd(pblk, rqd, READ);
+	return ret;
+}
+
+static int pblk_sched_meta_io(struct pblk *pblk, struct ppa_addr *prev_list,
+			       int prev_n)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line *meta_line;
+
+	spin_lock(&l_mg->close_lock);
+retry:
+	if (list_empty(&l_mg->emeta_list)) {
+		spin_unlock(&l_mg->close_lock);
+		return 0;
+	}
+	meta_line = list_first_entry(&l_mg->emeta_list, struct pblk_line, list);
+	if (bitmap_full(meta_line->map_bitmap, lm->sec_per_line))
+		goto retry;
+	spin_unlock(&l_mg->close_lock);
+
+	if (!pblk_valid_meta_ppa(pblk, meta_line, prev_list, prev_n))
+		return 0;
+
+	return pblk_submit_meta_io(pblk, meta_line);
+}
+
 static int pblk_submit_io_set(struct pblk *pblk, struct nvm_rq *rqd)
 {
 	struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
@@ -308,24 +498,39 @@ static int pblk_submit_io_set(struct pblk *pblk, struct nvm_rq *rqd)
 		return NVM_IO_ERR;
 	}
 
-	/* Submit write for current data line */
-	err = pblk_submit_io(pblk, rqd);
-	if (err) {
-		pr_err("pblk: I/O submission failed: %d\n", err);
-		return NVM_IO_ERR;
-	}
+	if (likely(ppa_empty(erase_ppa))) {
+		/* Submit metadata write for previous data line */
+		err = pblk_sched_meta_io(pblk, rqd->ppa_list, rqd->nr_ppas);
+		if (err) {
+			pr_err("pblk: metadata I/O submission failed: %d", err);
+			return NVM_IO_ERR;
+		}
 
-	/* Submit available erase for next data line */
-	if (unlikely(!ppa_empty(erase_ppa)) &&
-				pblk_blk_erase_async(pblk, erase_ppa)) {
-		struct pblk_line *e_line = pblk_line_get_erase(pblk);
-		struct nvm_tgt_dev *dev = pblk->dev;
-		struct nvm_geo *geo = &dev->geo;
-		int bit;
+		/* Submit data write for current data line */
+		err = pblk_submit_io(pblk, rqd);
+		if (err) {
+			pr_err("pblk: data I/O submission failed: %d\n", err);
+			return NVM_IO_ERR;
+		}
+	} else {
+		/* Submit data write for current data line */
+		err = pblk_submit_io(pblk, rqd);
+		if (err) {
+			pr_err("pblk: data I/O submission failed: %d\n", err);
+			return NVM_IO_ERR;
+		}
 
-		atomic_inc(&e_line->left_eblks);
-		bit = erase_ppa.g.lun * geo->nr_chnls + erase_ppa.g.ch;
-		WARN_ON(!test_and_clear_bit(bit, e_line->erase_bitmap));
+		/* Submit available erase for next data line */
+		if (pblk_blk_erase_async(pblk, erase_ppa)) {
+			struct pblk_line *e_line = pblk_line_get_erase(pblk);
+			struct nvm_tgt_dev *dev = pblk->dev;
+			struct nvm_geo *geo = &dev->geo;
+			int bit;
+
+			atomic_inc(&e_line->left_eblks);
+			bit = pblk_ppa_to_pos(geo, erase_ppa);
+			WARN_ON(!test_and_clear_bit(bit, e_line->erase_bitmap));
+		}
 	}
 
 	return NVM_IO_OK;
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index 136cc2ed5b2f..954a0733510b 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -258,8 +258,6 @@ struct pblk_rl {
 	atomic_t free_blocks;
 };
 
-#define PBLK_LINE_NR_LUN_BITMAP 2
-#define PBLK_LINE_NR_SEC_BITMAP 2
 #define PBLK_LINE_EMPTY (~0U)
 
 enum {
@@ -310,16 +308,19 @@ struct line_smeta {
 	__le32 window_wr_lun;	/* Number of parallel LUNs to write */
 
 	__le32 rsvd[2];
+
+	__le64 lun_bitmap[];
 };
 
 /*
- * Metadata Layout:
- *	1. struct pblk_emeta
- *	2. nr_lbas u64 forming lba list
- *	3. nr_lines (all) u32 valid sector count (vsc) (~0U: non-alloc line)
- *	4. nr_luns bits (u64 format) forming line bad block bitmap
- *
- *	3. and 4. will be part of FTL log
+ * Metadata layout in media:
+ *	First sector:
+ *		1. struct line_emeta
+ *		2. bad block bitmap (u64 * window_wr_lun)
+ *	Mid sectors (start at lbas_sector):
+ *		3. nr_lbas (u64) forming lba list
+ *	Last sectors (start at vsc_sector):
+ *		4. u32 valid sector count (vsc) for all lines (~0U: free line)
  */
 struct line_emeta {
 	struct line_header header;
@@ -339,6 +340,23 @@ struct line_emeta {
 	__le32 next_id;		/* Line id for next line */
 	__le64 nr_lbas;		/* Number of lbas mapped in line */
 	__le64 nr_valid_lbas;	/* Number of valid lbas mapped in line */
+	__le64 bb_bitmap[];	/* Updated bad block bitmap for line */
+};
+
+struct pblk_emeta {
+	struct line_emeta *buf;		/* emeta buffer in media format */
+	int mem;			/* Write offset - points to next
+					 * writable entry in memory
+					 */
+	atomic_t sync;			/* Synced - backpointer that signals the
+					 * last entry that has been successfully
+					 * persisted to media
+					 */
+	unsigned int nr_entries;	/* Number of emeta entries */
+};
+
+struct pblk_smeta {
+	struct line_smeta *buf;		/* smeta buffer in persistent format */
 };
 
 struct pblk_line {
@@ -355,9 +373,12 @@ struct pblk_line {
 
 	unsigned long *lun_bitmap;	/* Bitmap for LUNs mapped in line */
 
-	struct line_smeta *smeta;	/* Start metadata */
-	struct line_emeta *emeta;	/* End metadata */
+	struct pblk_smeta *smeta;	/* Start metadata */
+	struct pblk_emeta *emeta;	/* End medatada */
+
 	int meta_line;			/* Metadata line id */
+	int meta_distance;		/* Distance between data and metadata */
+
 	u64 smeta_ssec;			/* Sector where smeta starts */
 	u64 emeta_ssec;			/* Sector where emeta starts */
 
@@ -376,7 +397,9 @@ struct pblk_line {
 	int left_msecs;			/* Sectors left for mapping */
 	int left_ssecs;			/* Sectors left to sync */
 	unsigned int cur_sec;		/* Sector map pointer */
-	unsigned int vsc;		/* Valid sector count in line */
+	unsigned int nr_valid_lbas;	/* Number of valid lbas in line */
+
+	__le32 *vsc;			/* Valid sector count in line */
 
 	struct kref ref;		/* Write buffer L2P references */
 
@@ -385,13 +408,15 @@ struct pblk_line {
 
 #define PBLK_DATA_LINES 4
 
-enum{
+enum {
 	PBLK_KMALLOC_META = 1,
 	PBLK_VMALLOC_META = 2,
 };
 
-struct pblk_line_metadata {
-	void *meta;
+enum {
+	PBLK_EMETA_TYPE_HEADER = 1,	/* struct line_emeta first sector */
+	PBLK_EMETA_TYPE_LLBA = 2,	/* lba list - type: __le64 */
+	PBLK_EMETA_TYPE_VSC = 3,	/* vsc list - type: __le32 */
 };
 
 struct pblk_line_mgmt {
@@ -417,13 +442,17 @@ struct pblk_line_mgmt {
 	struct pblk_line *log_next;	/* Next FTL log line */
 	struct pblk_line *data_next;	/* Next data line */
 
+	struct list_head emeta_list;	/* Lines queued to schedule emeta */
+
+	__le32 *vsc_list;		/* Valid sector counts for all lines */
+
 	/* Metadata allocation type: VMALLOC | KMALLOC */
 	int smeta_alloc_type;
 	int emeta_alloc_type;
 
 	/* Pre-allocated metadata for data lines */
-	struct pblk_line_metadata sline_meta[PBLK_DATA_LINES];
-	struct pblk_line_metadata eline_meta[PBLK_DATA_LINES];
+	struct pblk_smeta *sline_meta[PBLK_DATA_LINES];
+	struct pblk_emeta *eline_meta[PBLK_DATA_LINES];
 	unsigned long meta_bitmap;
 
 	/* Helpers for fast bitmap calculations */
@@ -434,25 +463,40 @@ struct pblk_line_mgmt {
 	unsigned long l_seq_nr;		/* Log line unique sequence number */
 
 	spinlock_t free_lock;
+	spinlock_t close_lock;
 	spinlock_t gc_lock;
 };
 
 struct pblk_line_meta {
 	unsigned int smeta_len;		/* Total length for smeta */
-	unsigned int smeta_sec;		/* Sectors needed for smeta*/
-	unsigned int emeta_len;		/* Total length for emeta */
-	unsigned int emeta_sec;		/* Sectors needed for emeta*/
+	unsigned int smeta_sec;		/* Sectors needed for smeta */
+
+	unsigned int emeta_len[4];	/* Lengths for emeta:
+					 *  [0]: Total length
+					 *  [1]: struct line_emeta length
+					 *  [2]: L2P portion length
+					 *  [3]: vsc list length
+					 */
+	unsigned int emeta_sec[4];	/* Sectors needed for emeta. Same layout
+					 * as emeta_len
+					 */
+
 	unsigned int emeta_bb;		/* Boundary for bb that affects emeta */
+
+	unsigned int vsc_list_len;	/* Length for vsc list */
 	unsigned int sec_bitmap_len;	/* Length for sector bitmap in line */
 	unsigned int blk_bitmap_len;	/* Length for block bitmap in line */
 	unsigned int lun_bitmap_len;	/* Length for lun bitmap in line */
 
 	unsigned int blk_per_line;	/* Number of blocks in a full line */
 	unsigned int sec_per_line;	/* Number of sectors in a line */
+	unsigned int dsec_per_line;	/* Number of data sectors in a line */
 	unsigned int min_blk_line;	/* Min. number of good blocks in line */
 
 	unsigned int mid_thrs;		/* Threshold for GC mid list */
 	unsigned int high_thrs;		/* Threshold for GC high list */
+
+	unsigned int meta_distance;	/* Distance between data and metadata */
 };
 
 struct pblk_addr_format {
@@ -621,6 +665,7 @@ void pblk_discard(struct pblk *pblk, struct bio *bio);
 void pblk_log_write_err(struct pblk *pblk, struct nvm_rq *rqd);
 void pblk_log_read_err(struct pblk *pblk, struct nvm_rq *rqd);
 int pblk_submit_io(struct pblk *pblk, struct nvm_rq *rqd);
+int pblk_submit_meta_io(struct pblk *pblk, struct pblk_line *meta_line);
 struct bio *pblk_bio_map_addr(struct pblk *pblk, void *data,
 			      unsigned int nr_secs, unsigned int len,
 			      gfp_t gfp_mask);
@@ -634,18 +679,23 @@ struct pblk_line *pblk_line_get_erase(struct pblk *pblk);
 int pblk_line_erase(struct pblk *pblk, struct pblk_line *line);
 int pblk_line_is_full(struct pblk_line *line);
 void pblk_line_free(struct pblk *pblk, struct pblk_line *line);
-void pblk_line_close_ws(struct work_struct *work);
+void pblk_line_close_meta(struct pblk *pblk, struct pblk_line *line);
 void pblk_line_close(struct pblk *pblk, struct pblk_line *line);
+void pblk_line_close_ws(struct work_struct *work);
 void pblk_line_mark_bb(struct work_struct *work);
 void pblk_line_run_ws(struct pblk *pblk, struct pblk_line *line, void *priv,
 		      void (*work)(struct work_struct *));
 u64 pblk_line_smeta_start(struct pblk *pblk, struct pblk_line *line);
 int pblk_line_read_smeta(struct pblk *pblk, struct pblk_line *line);
-int pblk_line_read_emeta(struct pblk *pblk, struct pblk_line *line);
+int pblk_line_read_emeta(struct pblk *pblk, struct pblk_line *line,
+			 void *emeta_buf);
 int pblk_blk_erase_async(struct pblk *pblk, struct ppa_addr erase_ppa);
 void pblk_line_put(struct kref *ref);
 struct list_head *pblk_line_gc_list(struct pblk *pblk, struct pblk_line *line);
+u64 pblk_lookup_page(struct pblk *pblk, struct pblk_line *line);
+void pblk_dealloc_page(struct pblk *pblk, struct pblk_line *line, int nr_secs);
 u64 pblk_alloc_page(struct pblk *pblk, struct pblk_line *line, int nr_secs);
+u64 __pblk_alloc_page(struct pblk *pblk, struct pblk_line *line, int nr_secs);
 int pblk_calc_secs(struct pblk *pblk, unsigned long secs_avail,
 		   unsigned long secs_to_flush);
 void pblk_down_rq(struct pblk *pblk, struct ppa_addr *ppa_list, int nr_ppas,
@@ -774,9 +824,19 @@ static inline struct nvm_rq *nvm_rq_from_c_ctx(void *c_ctx)
 	return c_ctx - sizeof(struct nvm_rq);
 }
 
-static inline void *pblk_line_emeta_to_lbas(struct line_emeta *emeta)
+static inline void *emeta_to_bb(struct line_emeta *emeta)
 {
-	return (emeta) + 1;
+	return emeta->bb_bitmap;
+}
+
+static inline void *emeta_to_lbas(struct pblk *pblk, struct line_emeta *emeta)
+{
+	return ((void *)emeta + pblk->lm.emeta_len[1]);
+}
+
+static inline void *emeta_to_vsc(struct pblk *pblk, struct line_emeta *emeta)
+{
+	return (emeta_to_lbas(pblk, emeta) + pblk->lm.emeta_len[2]);
 }
 
 #define NVM_MEM_PAGE_WRITE (8)
@@ -964,11 +1024,11 @@ static inline struct ppa_addr addr_to_pblk_ppa(struct pblk *pblk, u64 paddr,
 }
 
 static inline u32 pblk_calc_meta_header_crc(struct pblk *pblk,
-					    struct line_smeta *smeta)
+					    struct line_header *header)
 {
 	u32 crc = ~(u32)0;
 
-	crc = crc32_le(crc, (unsigned char *)smeta + sizeof(crc),
+	crc = crc32_le(crc, (unsigned char *)header + sizeof(crc),
 				sizeof(struct line_header) - sizeof(crc));
 
 	return crc;
@@ -996,7 +1056,7 @@ static inline u32 pblk_calc_emeta_crc(struct pblk *pblk,
 
 	crc = crc32_le(crc, (unsigned char *)emeta +
 				sizeof(struct line_header) + sizeof(crc),
-				lm->emeta_len -
+				lm->emeta_len[0] -
 				sizeof(struct line_header) - sizeof(crc));
 
 	return crc;
-- 
2.7.4

[PATCH 09/20] lightnvm: pblk: delete redundant debug line stat

[Javier González]

Remove a legacy variable that helped verifying the consistency of the
run-time metadata for the free line list. With the new metadata layout,
this check is no longer necessary.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/pblk-sysfs.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/lightnvm/pblk-sysfs.c b/drivers/lightnvm/pblk-sysfs.c
index 707d1b91bde6..3d9a77646a3d 100644
--- a/drivers/lightnvm/pblk-sysfs.c
+++ b/drivers/lightnvm/pblk-sysfs.c
@@ -153,7 +153,7 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page)
 	int free_line_cnt = 0, closed_line_cnt = 0, emeta_line_cnt = 0;
 	int d_line_cnt = 0, l_line_cnt = 0;
 	int gc_full = 0, gc_high = 0, gc_mid = 0, gc_low = 0, gc_empty = 0;
-	int free = 0, bad = 0, cor = 0;
+	int bad = 0, cor = 0;
 	int msecs = 0, ssecs = 0, cur_sec = 0, vsc = 0, sec_in_line = 0;
 	int map_weight = 0, meta_weight = 0;
 
@@ -217,8 +217,6 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page)
 		gc_empty++;
 	}
 
-	list_for_each_entry(line, &l_mg->free_list, list)
-		free++;
 	list_for_each_entry(line, &l_mg->bad_list, list)
 		bad++;
 	list_for_each_entry(line, &l_mg->corrupt_list, list)
@@ -247,9 +245,9 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page)
 		geo->nr_luns, lm->blk_per_line, lm->sec_per_line);
 
 	sz += snprintf(page + sz, PAGE_SIZE - sz,
-		"lines:d:%d,l:%d-f:%d(%d),m:%d,c:%d,b:%d,co:%d(d:%d,l:%d)t:%d\n",
+		"lines:d:%d,l:%d-f:%d,m:%d,c:%d,b:%d,co:%d(d:%d,l:%d)t:%d\n",
 					cur_data, cur_log,
-					free, nr_free_lines, emeta_line_cnt,
+					nr_free_lines, emeta_line_cnt,
 					closed_line_cnt,
 					bad, cor,
 					d_line_cnt, l_line_cnt,
-- 
2.7.4

[PATCH 10/20] lightnvm: pblk: delete redundant buffer pointer

[Javier González]

After refactoring the metadata path, the backpointer controlling
synced I/Os in a line becomes unnecessary; metadata is scheduled
on the write thread, thus we know when the end of the line is reached
and act on it directly.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/pblk-core.c     | 18 +++---------------
 drivers/lightnvm/pblk-init.c     |  1 -
 drivers/lightnvm/pblk-map.c      |  2 +-
 drivers/lightnvm/pblk-recovery.c |  2 --
 drivers/lightnvm/pblk-sysfs.c    | 10 ++++------
 drivers/lightnvm/pblk-write.c    | 13 +------------
 drivers/lightnvm/pblk.h          |  6 ++----
 7 files changed, 11 insertions(+), 41 deletions(-)

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index 6e4b06f841e7..beae1618483f 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -65,8 +65,8 @@ static void pblk_end_io_erase(struct nvm_rq *rqd)
 	mempool_free(rqd, pblk->g_rq_pool);
 }
 
-static void __pblk_map_invalidate(struct pblk *pblk, struct pblk_line *line,
-				  u64 paddr)
+void __pblk_map_invalidate(struct pblk *pblk, struct pblk_line *line,
+			   u64 paddr)
 {
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 	struct list_head *move_list = NULL;
@@ -129,18 +129,6 @@ void pblk_map_invalidate(struct pblk *pblk, struct ppa_addr ppa)
 	__pblk_map_invalidate(pblk, line, paddr);
 }
 
-void pblk_map_pad_invalidate(struct pblk *pblk, struct pblk_line *line,
-			     u64 paddr)
-{
-	__pblk_map_invalidate(pblk, line, paddr);
-
-	pblk_rb_sync_init(&pblk->rwb, NULL);
-	line->left_ssecs--;
-	if (!line->left_ssecs)
-		pblk_line_run_ws(pblk, line, NULL, pblk_line_close_ws);
-	pblk_rb_sync_end(&pblk->rwb, NULL);
-}
-
 static void pblk_invalidate_range(struct pblk *pblk, sector_t slba,
 				  unsigned int nr_secs)
 {
@@ -1057,7 +1045,7 @@ static int pblk_line_init_bb(struct pblk *pblk, struct pblk_line *line,
 	line->sec_in_line -= lm->emeta_sec[0];
 	line->emeta_ssec = off;
 	line->nr_valid_lbas = 0;
-	line->left_ssecs = line->left_msecs = line->sec_in_line;
+	line->left_msecs = line->sec_in_line;
 	*line->vsc = cpu_to_le32(line->sec_in_line);
 
 	if (lm->sec_per_line - line->sec_in_line !=
diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
index e51b965ae6a9..968c2e390cef 100644
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -889,7 +889,6 @@ static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
 	atomic_long_set(&pblk->req_writes, 0);
 	atomic_long_set(&pblk->sub_writes, 0);
 	atomic_long_set(&pblk->sync_writes, 0);
-	atomic_long_set(&pblk->compl_writes, 0);
 	atomic_long_set(&pblk->inflight_reads, 0);
 	atomic_long_set(&pblk->cache_reads, 0);
 	atomic_long_set(&pblk->sync_reads, 0);
diff --git a/drivers/lightnvm/pblk-map.c b/drivers/lightnvm/pblk-map.c
index 08580a649499..9942d9bc7b3a 100644
--- a/drivers/lightnvm/pblk-map.c
+++ b/drivers/lightnvm/pblk-map.c
@@ -56,7 +56,7 @@ static void pblk_map_page_data(struct pblk *pblk, unsigned int sentry,
 			u64 addr_empty = cpu_to_le64(ADDR_EMPTY);
 
 			lba_list[paddr] = meta_list[i].lba = addr_empty;
-			pblk_map_pad_invalidate(pblk, line, paddr);
+			__pblk_map_invalidate(pblk, line, paddr);
 		}
 	}
 
diff --git a/drivers/lightnvm/pblk-recovery.c b/drivers/lightnvm/pblk-recovery.c
index ba02d0bc3e45..7b0ace2f4957 100644
--- a/drivers/lightnvm/pblk-recovery.c
+++ b/drivers/lightnvm/pblk-recovery.c
@@ -553,7 +553,6 @@ static int pblk_recov_scan_all_oob(struct pblk *pblk, struct pblk_line *line,
 		if (ret)
 			pr_err("pblk: OOB read failed (err:%d)\n", ret);
 
-		line->left_ssecs = line->left_msecs;
 		left_ppas = 0;
 	}
 
@@ -659,7 +658,6 @@ static int pblk_recov_scan_oob(struct pblk *pblk, struct pblk_line *line,
 		/* Roll back failed sectors */
 		line->cur_sec -= nr_error_bits;
 		line->left_msecs += nr_error_bits;
-		line->left_ssecs = line->left_msecs;
 		bitmap_clear(line->map_bitmap, line->cur_sec, nr_error_bits);
 
 		left_ppas = 0;
diff --git a/drivers/lightnvm/pblk-sysfs.c b/drivers/lightnvm/pblk-sysfs.c
index 3d9a77646a3d..e1e92c9498a9 100644
--- a/drivers/lightnvm/pblk-sysfs.c
+++ b/drivers/lightnvm/pblk-sysfs.c
@@ -154,7 +154,7 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page)
 	int d_line_cnt = 0, l_line_cnt = 0;
 	int gc_full = 0, gc_high = 0, gc_mid = 0, gc_low = 0, gc_empty = 0;
 	int bad = 0, cor = 0;
-	int msecs = 0, ssecs = 0, cur_sec = 0, vsc = 0, sec_in_line = 0;
+	int msecs = 0, cur_sec = 0, vsc = 0, sec_in_line = 0;
 	int map_weight = 0, meta_weight = 0;
 
 	spin_lock(&l_mg->free_lock);
@@ -227,7 +227,6 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page)
 	if (l_mg->data_line) {
 		cur_sec = l_mg->data_line->cur_sec;
 		msecs = l_mg->data_line->left_msecs;
-		ssecs = l_mg->data_line->left_ssecs;
 		vsc = le32_to_cpu(*l_mg->data_line->vsc);
 		sec_in_line = l_mg->data_line->sec_in_line;
 		meta_weight = bitmap_weight(&l_mg->meta_bitmap,
@@ -259,8 +258,8 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page)
 			atomic_read(&pblk->gc.inflight_gc));
 
 	sz += snprintf(page + sz, PAGE_SIZE - sz,
-		"data (%d) cur:%d, left:%d/%d, vsc:%d, s:%d, map:%d/%d (%d)\n",
-			cur_data, cur_sec, msecs, ssecs, vsc, sec_in_line,
+		"data (%d) cur:%d, left:%d, vsc:%d, s:%d, map:%d/%d (%d)\n",
+			cur_data, cur_sec, msecs, vsc, sec_in_line,
 			map_weight, lm->sec_per_line, meta_weight);
 
 	return sz;
@@ -303,7 +302,7 @@ static ssize_t pblk_sysfs_get_sec_per_write(struct pblk *pblk, char *page)
 static ssize_t pblk_sysfs_stats_debug(struct pblk *pblk, char *page)
 {
 	return snprintf(page, PAGE_SIZE,
-		"%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\n",
+		"%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\n",
 			atomic_long_read(&pblk->inflight_writes),
 			atomic_long_read(&pblk->inflight_reads),
 			atomic_long_read(&pblk->req_writes),
@@ -312,7 +311,6 @@ static ssize_t pblk_sysfs_stats_debug(struct pblk *pblk, char *page)
 			atomic_long_read(&pblk->padded_wb),
 			atomic_long_read(&pblk->sub_writes),
 			atomic_long_read(&pblk->sync_writes),
-			atomic_long_read(&pblk->compl_writes),
 			atomic_long_read(&pblk->recov_writes),
 			atomic_long_read(&pblk->recov_gc_writes),
 			atomic_long_read(&pblk->recov_gc_reads),
diff --git a/drivers/lightnvm/pblk-write.c b/drivers/lightnvm/pblk-write.c
index 1739c970692e..a29a34786ac5 100644
--- a/drivers/lightnvm/pblk-write.c
+++ b/drivers/lightnvm/pblk-write.c
@@ -17,16 +17,6 @@
 
 #include "pblk.h"
 
-static void pblk_sync_line(struct pblk *pblk, struct pblk_line *line)
-{
-#ifdef CONFIG_NVM_DEBUG
-	atomic_long_inc(&pblk->sync_writes);
-#endif
-
-	/* Counter protected by rb sync lock */
-	line->left_ssecs--;
-}
-
 static unsigned long pblk_end_w_bio(struct pblk *pblk, struct nvm_rq *rqd,
 				    struct pblk_c_ctx *c_ctx)
 {
@@ -44,14 +34,13 @@ static unsigned long pblk_end_w_bio(struct pblk *pblk, struct nvm_rq *rqd,
 
 		p = rqd->ppa_list[i];
 		line = &pblk->lines[pblk_dev_ppa_to_line(p)];
-		pblk_sync_line(pblk, line);
 
 		while ((original_bio = bio_list_pop(&w_ctx->bios)))
 			bio_endio(original_bio);
 	}
 
 #ifdef CONFIG_NVM_DEBUG
-	atomic_long_add(c_ctx->nr_valid, &pblk->compl_writes);
+	atomic_long_add(c_ctx->nr_valid, &pblk->sync_writes);
 #endif
 
 	ret = pblk_rb_sync_advance(&pblk->rwb, c_ctx->nr_valid);
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index 954a0733510b..407d15c69fb4 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -395,7 +395,6 @@ struct pblk_line {
 	atomic_t left_seblks;		/* Blocks left for sync erasing */
 
 	int left_msecs;			/* Sectors left for mapping */
-	int left_ssecs;			/* Sectors left to sync */
 	unsigned int cur_sec;		/* Sector map pointer */
 	unsigned int nr_valid_lbas;	/* Number of valid lbas in line */
 
@@ -555,7 +554,6 @@ struct pblk {
 	atomic_long_t req_writes;	/* Sectors stored on write buffer */
 	atomic_long_t sub_writes;	/* Sectors submitted from buffer */
 	atomic_long_t sync_writes;	/* Sectors synced to media */
-	atomic_long_t compl_writes;	/* Sectors completed in write bio */
 	atomic_long_t inflight_reads;	/* Inflight sector read requests */
 	atomic_long_t cache_reads;	/* Read requests that hit the cache */
 	atomic_long_t sync_reads;	/* Completed sector read requests */
@@ -706,11 +704,11 @@ void pblk_end_bio_sync(struct bio *bio);
 void pblk_end_io_sync(struct nvm_rq *rqd);
 int pblk_bio_add_pages(struct pblk *pblk, struct bio *bio, gfp_t flags,
 		       int nr_pages);
-void pblk_map_pad_invalidate(struct pblk *pblk, struct pblk_line *line,
-			     u64 paddr);
 void pblk_bio_free_pages(struct pblk *pblk, struct bio *bio, int off,
 			 int nr_pages);
 void pblk_map_invalidate(struct pblk *pblk, struct ppa_addr ppa);
+void __pblk_map_invalidate(struct pblk *pblk, struct pblk_line *line,
+			   u64 paddr);
 void pblk_update_map(struct pblk *pblk, sector_t lba, struct ppa_addr ppa);
 void pblk_update_map_cache(struct pblk *pblk, sector_t lba,
 			   struct ppa_addr ppa);
-- 
2.7.4

[PATCH 11/20] lightnvm: pblk: issue multiplane reads if possible

[Javier González]

If a read request is sequential and its size aligns with a
multi-plane page size, use the multi-plane hint to process the I/O in
parallel in the controller.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/pblk-core.c     | 12 +++++++-----
 drivers/lightnvm/pblk-read.c     | 11 +++++++++--
 drivers/lightnvm/pblk-recovery.c | 18 +++++++++++++++---
 drivers/lightnvm/pblk.h          | 22 ++++++++++++++++++++--
 4 files changed, 51 insertions(+), 12 deletions(-)

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index beae1618483f..29565f89a85e 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -564,7 +564,6 @@ static int pblk_line_submit_emeta_io(struct pblk *pblk, struct pblk_line *line,
 	int id = line->id;
 	int rq_ppas, rq_len;
 	int cmd_op, bio_op;
-	int flags;
 	int i, j;
 	int ret;
 	DECLARE_COMPLETION_ONSTACK(wait);
@@ -572,11 +571,9 @@ static int pblk_line_submit_emeta_io(struct pblk *pblk, struct pblk_line *line,
 	if (dir == WRITE) {
 		bio_op = REQ_OP_WRITE;
 		cmd_op = NVM_OP_PWRITE;
-		flags = pblk_set_progr_mode(pblk, WRITE);
 	} else if (dir == READ) {
 		bio_op = REQ_OP_READ;
 		cmd_op = NVM_OP_PREAD;
-		flags = pblk_set_read_mode(pblk);
 	} else
 		return -EINVAL;
 
@@ -601,7 +598,6 @@ static int pblk_line_submit_emeta_io(struct pblk *pblk, struct pblk_line *line,
 
 	rqd.bio = bio;
 	rqd.opcode = cmd_op;
-	rqd.flags = flags;
 	rqd.nr_ppas = rq_ppas;
 	rqd.ppa_list = ppa_list;
 	rqd.dma_ppa_list = dma_ppa_list;
@@ -609,6 +605,7 @@ static int pblk_line_submit_emeta_io(struct pblk *pblk, struct pblk_line *line,
 	rqd.private = &wait;
 
 	if (dir == WRITE) {
+		rqd.flags = pblk_set_progr_mode(pblk, WRITE);
 		for (i = 0; i < rqd.nr_ppas; ) {
 			spin_lock(&line->lock);
 			paddr = __pblk_alloc_page(pblk, line, min);
@@ -621,6 +618,11 @@ static int pblk_line_submit_emeta_io(struct pblk *pblk, struct pblk_line *line,
 		for (i = 0; i < rqd.nr_ppas; ) {
 			struct ppa_addr ppa = addr_to_gen_ppa(pblk, paddr, id);
 			int pos = pblk_dev_ppa_to_pos(geo, ppa);
+			int read_type = PBLK_READ_RANDOM;
+
+			if (pblk_io_aligned(pblk, rq_ppas))
+				read_type = PBLK_READ_SEQUENTIAL;
+			rqd.flags = pblk_set_read_mode(pblk, read_type);
 
 			while (test_bit(pos, line->blk_bitmap)) {
 				paddr += min;
@@ -717,7 +719,7 @@ static int pblk_line_submit_smeta_io(struct pblk *pblk, struct pblk_line *line,
 	} else if (dir == READ) {
 		bio_op = REQ_OP_READ;
 		cmd_op = NVM_OP_PREAD;
-		flags = pblk_set_read_mode(pblk);
+		flags = pblk_set_read_mode(pblk, PBLK_READ_SEQUENTIAL);
 	} else
 		return -EINVAL;
 
diff --git a/drivers/lightnvm/pblk-read.c b/drivers/lightnvm/pblk-read.c
index cea958e96fc3..d6499cdb7d33 100644
--- a/drivers/lightnvm/pblk-read.c
+++ b/drivers/lightnvm/pblk-read.c
@@ -88,6 +88,11 @@ static void pblk_read_ppalist_rq(struct pblk *pblk, struct nvm_rq *rqd,
 			bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
 	}
 
+	if (pblk_io_aligned(pblk, nr_secs))
+		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_SEQUENTIAL);
+	else
+		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
+
 #ifdef CONFIG_NVM_DEBUG
 	atomic_long_add(nr_secs, &pblk->inflight_reads);
 #endif
@@ -97,8 +102,6 @@ static int pblk_submit_read_io(struct pblk *pblk, struct nvm_rq *rqd)
 {
 	int err;
 
-	rqd->flags = pblk_set_read_mode(pblk);
-
 	err = pblk_submit_io(pblk, rqd);
 	if (err)
 		return NVM_IO_ERR;
@@ -177,6 +180,7 @@ static int pblk_fill_partial_read_bio(struct pblk *pblk, struct nvm_rq *rqd,
 
 	rqd->bio = new_bio;
 	rqd->nr_ppas = nr_holes;
+	rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
 	rqd->end_io = NULL;
 
 	if (unlikely(nr_secs > 1 && nr_holes == 1)) {
@@ -290,6 +294,8 @@ static void pblk_read_rq(struct pblk *pblk, struct nvm_rq *rqd,
 	} else {
 		rqd->ppa_addr = ppa;
 	}
+
+	rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
 }
 
 int pblk_submit_read(struct pblk *pblk, struct bio *bio)
@@ -497,6 +503,7 @@ int pblk_submit_read_gc(struct pblk *pblk, u64 *lba_list, void *data,
 	rqd.end_io = pblk_end_io_sync;
 	rqd.private = &wait;
 	rqd.nr_ppas = *secs_to_gc;
+	rqd.flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
 	rqd.bio = bio;
 
 	ret = pblk_submit_read_io(pblk, &rqd);
diff --git a/drivers/lightnvm/pblk-recovery.c b/drivers/lightnvm/pblk-recovery.c
index 7b0ace2f4957..b9f2b40bd5a7 100644
--- a/drivers/lightnvm/pblk-recovery.c
+++ b/drivers/lightnvm/pblk-recovery.c
@@ -257,7 +257,6 @@ static int pblk_recov_read_oob(struct pblk *pblk, struct pblk_line *line,
 
 	rqd->bio = bio;
 	rqd->opcode = NVM_OP_PREAD;
-	rqd->flags = pblk_set_read_mode(pblk);
 	rqd->meta_list = meta_list;
 	rqd->nr_ppas = rq_ppas;
 	rqd->ppa_list = ppa_list;
@@ -266,6 +265,11 @@ static int pblk_recov_read_oob(struct pblk *pblk, struct pblk_line *line,
 	rqd->end_io = pblk_end_io_sync;
 	rqd->private = &wait;
 
+	if (pblk_io_aligned(pblk, rq_ppas))
+		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_SEQUENTIAL);
+	else
+		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
+
 	for (i = 0; i < rqd->nr_ppas; ) {
 		struct ppa_addr ppa;
 		int pos;
@@ -473,7 +477,6 @@ static int pblk_recov_scan_all_oob(struct pblk *pblk, struct pblk_line *line,
 
 	rqd->bio = bio;
 	rqd->opcode = NVM_OP_PREAD;
-	rqd->flags = pblk_set_read_mode(pblk);
 	rqd->meta_list = meta_list;
 	rqd->nr_ppas = rq_ppas;
 	rqd->ppa_list = ppa_list;
@@ -482,6 +485,11 @@ static int pblk_recov_scan_all_oob(struct pblk *pblk, struct pblk_line *line,
 	rqd->end_io = pblk_end_io_sync;
 	rqd->private = &wait;
 
+	if (pblk_io_aligned(pblk, rq_ppas))
+		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_SEQUENTIAL);
+	else
+		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
+
 	for (i = 0; i < rqd->nr_ppas; ) {
 		struct ppa_addr ppa;
 		int pos;
@@ -607,7 +615,6 @@ static int pblk_recov_scan_oob(struct pblk *pblk, struct pblk_line *line,
 
 	rqd->bio = bio;
 	rqd->opcode = NVM_OP_PREAD;
-	rqd->flags = pblk_set_read_mode(pblk);
 	rqd->meta_list = meta_list;
 	rqd->nr_ppas = rq_ppas;
 	rqd->ppa_list = ppa_list;
@@ -616,6 +623,11 @@ static int pblk_recov_scan_oob(struct pblk *pblk, struct pblk_line *line,
 	rqd->end_io = pblk_end_io_sync;
 	rqd->private = &wait;
 
+	if (pblk_io_aligned(pblk, rq_ppas))
+		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_SEQUENTIAL);
+	else
+		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
+
 	for (i = 0; i < rqd->nr_ppas; ) {
 		struct ppa_addr ppa;
 		int pos;
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index 407d15c69fb4..eb8515fd9044 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -1074,9 +1074,27 @@ static inline int pblk_set_progr_mode(struct pblk *pblk, int type)
 	return flags;
 }
 
-static inline int pblk_set_read_mode(struct pblk *pblk)
+enum {
+	PBLK_READ_RANDOM	= 0,
+	PBLK_READ_SEQUENTIAL	= 1,
+};
+
+static inline int pblk_set_read_mode(struct pblk *pblk, int type)
 {
-	return NVM_IO_SNGL_ACCESS | NVM_IO_SUSPEND | NVM_IO_SCRAMBLE_ENABLE;
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	int flags;
+
+	flags = NVM_IO_SUSPEND | NVM_IO_SCRAMBLE_ENABLE;
+	if (type == PBLK_READ_SEQUENTIAL)
+		flags |= geo->plane_mode >> 1;
+
+	return flags;
+}
+
+static inline int pblk_io_aligned(struct pblk *pblk, int nr_secs)
+{
+	return !(nr_secs % pblk->min_write_pgs);
 }
 
 #ifdef CONFIG_NVM_DEBUG
-- 
2.7.4

[PATCH 12/20] lightnvm: pblk: simplify meta. memory allocation

[Javier González]

smeta size will always be suitable for a kmalloc allocation. Simplify
the code and leave the vmalloc fallback only for emeta, where the pblk
configuration has an impact.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/pblk-core.c  | 3 ++-
 drivers/lightnvm/pblk-init.c  | 9 ++++-----
 drivers/lightnvm/pblk-write.c | 3 ++-
 drivers/lightnvm/pblk.h       | 1 -
 4 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index 29565f89a85e..b5f7f3f19105 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -665,7 +665,8 @@ static int pblk_line_submit_emeta_io(struct pblk *pblk, struct pblk_line *line,
 	}
 	reinit_completion(&wait);
 
-	bio_put(bio);
+	if (likely(pblk->l_mg.emeta_alloc_type == PBLK_VMALLOC_META))
+		bio_put(bio);
 
 	if (rqd.error) {
 		if (dir == WRITE)
diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
index 968c2e390cef..c49115d74e85 100644
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -354,9 +354,9 @@ static void pblk_line_meta_free(struct pblk *pblk)
 	kfree(l_mg->vsc_list);
 
 	for (i = 0; i < PBLK_DATA_LINES; i++) {
-		pblk_mfree(&l_mg->sline_meta[i], l_mg->smeta_alloc_type);
+		kfree(l_mg->sline_meta[i]);
 		pblk_mfree(l_mg->eline_meta[i]->buf, l_mg->emeta_alloc_type);
-		kfree(&l_mg->eline_meta[i]);
+		kfree(l_mg->eline_meta[i]);
 	}
 
 	kfree(pblk->lines);
@@ -549,7 +549,6 @@ static int pblk_lines_alloc_metadata(struct pblk *pblk)
 	/* smeta is always small enough to fit on a kmalloc memory allocation,
 	 * emeta depends on the number of LUNs allocated to the pblk instance
 	 */
-	l_mg->smeta_alloc_type = PBLK_KMALLOC_META;
 	for (i = 0; i < PBLK_DATA_LINES; i++) {
 		l_mg->sline_meta[i] = kmalloc(lm->smeta_len, GFP_KERNEL);
 		if (!l_mg->sline_meta[i])
@@ -603,12 +602,12 @@ static int pblk_lines_alloc_metadata(struct pblk *pblk)
 fail_free_emeta:
 	while (--i >= 0) {
 		vfree(l_mg->eline_meta[i]->buf);
-		kfree(&l_mg->eline_meta[i]);
+		kfree(l_mg->eline_meta[i]);
 	}
 
 fail_free_smeta:
 	for (i = 0; i < PBLK_DATA_LINES; i++)
-		pblk_mfree(&l_mg->sline_meta[i], l_mg->smeta_alloc_type);
+		kfree(l_mg->sline_meta[i]);
 
 	return -ENOMEM;
 }
diff --git a/drivers/lightnvm/pblk-write.c b/drivers/lightnvm/pblk-write.c
index a29a34786ac5..3db2cbe5b788 100644
--- a/drivers/lightnvm/pblk-write.c
+++ b/drivers/lightnvm/pblk-write.c
@@ -442,7 +442,8 @@ int pblk_submit_meta_io(struct pblk *pblk, struct pblk_line *meta_line)
 	list_add(&meta_line->list, &meta_line->list);
 	spin_unlock(&l_mg->close_lock);
 fail_free_bio:
-	bio_put(bio);
+	if (likely(l_mg->emeta_alloc_type == PBLK_VMALLOC_META))
+		bio_put(bio);
 fail_free_rqd:
 	pblk_free_rqd(pblk, rqd, READ);
 	return ret;
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index eb8515fd9044..6c8d01198e8b 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -446,7 +446,6 @@ struct pblk_line_mgmt {
 	__le32 *vsc_list;		/* Valid sector counts for all lines */
 
 	/* Metadata allocation type: VMALLOC | KMALLOC */
-	int smeta_alloc_type;
 	int emeta_alloc_type;
 
 	/* Pre-allocated metadata for data lines */
-- 
2.7.4

[PATCH 13/20] lightnvm: pblk: decouple bad block from line alloc

[Javier González]

Decouple bad block discovery from line allocation logic. This allows to
return meaningful error codes in case of bad block discovery failure.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/pblk-init.c | 55 ++++++++++++++++++++++++++++++--------------
 1 file changed, 38 insertions(+), 17 deletions(-)

diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
index c49115d74e85..41db12deaa49 100644
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -327,6 +327,12 @@ static void pblk_luns_free(struct pblk *pblk)
 	kfree(pblk->luns);
 }
 
+static void pblk_free_line_bitmaps(struct pblk_line *line)
+{
+	kfree(line->blk_bitmap);
+	kfree(line->erase_bitmap);
+}
+
 static void pblk_lines_free(struct pblk *pblk)
 {
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
@@ -338,8 +344,7 @@ static void pblk_lines_free(struct pblk *pblk)
 		line = &pblk->lines[i];
 
 		pblk_line_free(pblk, line);
-		kfree(line->blk_bitmap);
-		kfree(line->erase_bitmap);
+		pblk_free_line_bitmaps(line);
 	}
 	spin_unlock(&l_mg->free_lock);
 }
@@ -396,25 +401,16 @@ static int pblk_bb_discovery(struct nvm_tgt_dev *dev, struct pblk_lun *rlun)
 	return ret;
 }
 
-static int pblk_bb_line(struct pblk *pblk, struct nvm_geo *geo,
-			struct pblk_line *line)
+static int pblk_bb_line(struct pblk *pblk, struct pblk_line *line,
+			int blk_per_line)
 {
-	struct pblk_line_meta *lm = &pblk->lm;
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
 	struct pblk_lun *rlun;
 	int bb_cnt = 0;
 	int i;
 
-	line->blk_bitmap = kzalloc(lm->blk_bitmap_len, GFP_KERNEL);
-	if (!line->blk_bitmap)
-		return -ENOMEM;
-
-	line->erase_bitmap = kzalloc(lm->blk_bitmap_len, GFP_KERNEL);
-	if (!line->erase_bitmap) {
-		kfree(line->blk_bitmap);
-		return -ENOMEM;
-	}
-
-	for (i = 0; i < lm->blk_per_line; i++) {
+	for (i = 0; i < blk_per_line; i++) {
 		rlun = &pblk->luns[i];
 		if (rlun->bb_list[line->id] == NVM_BLK_T_FREE)
 			continue;
@@ -426,6 +422,23 @@ static int pblk_bb_line(struct pblk *pblk, struct nvm_geo *geo,
 	return bb_cnt;
 }
 
+static int pblk_alloc_line_bitmaps(struct pblk *pblk, struct pblk_line *line)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+
+	line->blk_bitmap = kzalloc(lm->blk_bitmap_len, GFP_KERNEL);
+	if (!line->blk_bitmap)
+		return -ENOMEM;
+
+	line->erase_bitmap = kzalloc(lm->blk_bitmap_len, GFP_KERNEL);
+	if (!line->erase_bitmap) {
+		kfree(line->blk_bitmap);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
 static int pblk_luns_init(struct pblk *pblk, struct ppa_addr *luns)
 {
 	struct nvm_tgt_dev *dev = pblk->dev;
@@ -748,8 +761,13 @@ static int pblk_lines_init(struct pblk *pblk)
 		line->vsc = &l_mg->vsc_list[i];
 		spin_lock_init(&line->lock);
 
-		nr_bad_blks = pblk_bb_line(pblk, geo, line);
+		ret = pblk_alloc_line_bitmaps(pblk, line);
+		if (ret)
+			goto fail_free_lines;
+
+		nr_bad_blks = pblk_bb_line(pblk, line, lm->blk_per_line);
 		if (nr_bad_blks < 0 || nr_bad_blks > lm->blk_per_line) {
+			pblk_free_line_bitmaps(line);
 			ret = -EINVAL;
 			goto fail_free_lines;
 		}
@@ -776,6 +794,9 @@ static int pblk_lines_init(struct pblk *pblk)
 
 	return 0;
 fail_free_lines:
+	while (--i >= 0)
+		pblk_free_line_bitmaps(&pblk->lines[i]);
+
 	kfree(pblk->lines);
 fail_free_bb_aux:
 	kfree(l_mg->bb_aux);
-- 
2.7.4

[PATCH 14/20] lightnvm: pblk: choose optimal victim GC line

[Javier González]

At the moment, we separate the closed lines on three different list
based on their number of valid sectors. GC recycles lines from each list
based on capacity. Lines from each list are taken in a FIFO fashion.

Since the number of lines is limited (it corresponds to the number of
blocks in a LUN, which is somewhere between 1000-2000), we can afford
scanning the lists to choose the optimal line to be recycled. This helps
specially in lines with a high number of valid sectors.

If the number of blocks per LUN increases, we will consider a more
efficient policy.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/pblk-gc.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/lightnvm/pblk-gc.c b/drivers/lightnvm/pblk-gc.c
index 2e7fb7a51854..f811e4ca63f4 100644
--- a/drivers/lightnvm/pblk-gc.c
+++ b/drivers/lightnvm/pblk-gc.c
@@ -287,6 +287,20 @@ static void pblk_gc_lines(struct pblk *pblk, struct list_head *gc_list)
 	}
 }
 
+static struct pblk_line *pblk_gc_get_victim_line(struct pblk *pblk,
+						 struct list_head *group_list)
+{
+	struct pblk_line *line, *victim;
+
+	victim = list_first_entry(group_list, struct pblk_line, list);
+	list_for_each_entry(line, group_list, list) {
+		if (*line->vsc < *victim->vsc)
+			victim = line;
+	}
+
+	return victim;
+}
+
 /*
  * Lines with no valid sectors will be returned to the free list immediately. If
  * GC is activated - either because the free block count is under the determined
@@ -332,7 +346,7 @@ static void pblk_gc_run(struct pblk *pblk)
 			return;
 		}
 
-		line = list_first_entry(group_list, struct pblk_line, list);
+		line = pblk_gc_get_victim_line(pblk, group_list);
 		nr_blocks_free += atomic_read(&line->blk_in_line);
 
 		spin_lock(&line->lock);
-- 
2.7.4

[PATCH 15/20] lightnvm: pblk: set metadata list for all I/Os

[Javier González]

Set a dma area for all I/Os in order to read/write from/to the metadata
stored on the per-sector out-of-bound area.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/pblk-core.c | 47 +++++++++++++++++++++++++++++++-------------
 drivers/lightnvm/pblk-read.c | 45 ++++++++++++++++++++----------------------
 2 files changed, 54 insertions(+), 38 deletions(-)

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index b5f7f3f19105..cba7cd78e4a6 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -555,10 +555,10 @@ static int pblk_line_submit_emeta_io(struct pblk *pblk, struct pblk_line *line,
 	struct nvm_tgt_dev *dev = pblk->dev;
 	struct nvm_geo *geo = &dev->geo;
 	struct pblk_line_meta *lm = &pblk->lm;
+	void *ppa_list, *meta_list;
 	struct bio *bio;
 	struct nvm_rq rqd;
-	struct ppa_addr *ppa_list;
-	dma_addr_t dma_ppa_list;
+	dma_addr_t dma_ppa_list, dma_meta_list;
 	int min = pblk->min_write_pgs;
 	int left_ppas = lm->emeta_sec[0];
 	int id = line->id;
@@ -577,10 +577,14 @@ static int pblk_line_submit_emeta_io(struct pblk *pblk, struct pblk_line *line,
 	} else
 		return -EINVAL;
 
-	ppa_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL, &dma_ppa_list);
-	if (!ppa_list)
+	meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
+							&dma_meta_list);
+	if (!meta_list)
 		return -ENOMEM;
 
+	ppa_list = meta_list + pblk_dma_meta_size;
+	dma_ppa_list = dma_meta_list + pblk_dma_meta_size;
+
 next_rq:
 	memset(&rqd, 0, sizeof(struct nvm_rq));
 
@@ -597,22 +601,28 @@ static int pblk_line_submit_emeta_io(struct pblk *pblk, struct pblk_line *line,
 	bio_set_op_attrs(bio, bio_op, 0);
 
 	rqd.bio = bio;
-	rqd.opcode = cmd_op;
-	rqd.nr_ppas = rq_ppas;
+	rqd.meta_list = meta_list;
 	rqd.ppa_list = ppa_list;
+	rqd.dma_meta_list = dma_meta_list;
 	rqd.dma_ppa_list = dma_ppa_list;
+	rqd.opcode = cmd_op;
+	rqd.nr_ppas = rq_ppas;
 	rqd.end_io = pblk_end_io_sync;
 	rqd.private = &wait;
 
 	if (dir == WRITE) {
+		struct pblk_sec_meta *meta_list = rqd.meta_list;
+
 		rqd.flags = pblk_set_progr_mode(pblk, WRITE);
 		for (i = 0; i < rqd.nr_ppas; ) {
 			spin_lock(&line->lock);
 			paddr = __pblk_alloc_page(pblk, line, min);
 			spin_unlock(&line->lock);
-			for (j = 0; j < min; j++, i++, paddr++)
+			for (j = 0; j < min; j++, i++, paddr++) {
+				meta_list[i].lba = cpu_to_le64(ADDR_EMPTY);
 				rqd.ppa_list[i] =
 					addr_to_gen_ppa(pblk, paddr, id);
+			}
 		}
 	} else {
 		for (i = 0; i < rqd.nr_ppas; ) {
@@ -680,7 +690,7 @@ static int pblk_line_submit_emeta_io(struct pblk *pblk, struct pblk_line *line,
 	if (left_ppas)
 		goto next_rq;
 free_rqd_dma:
-	nvm_dev_dma_free(dev->parent, ppa_list, dma_ppa_list);
+	nvm_dev_dma_free(dev->parent, rqd.meta_list, rqd.dma_meta_list);
 	return ret;
 }
 
@@ -726,11 +736,14 @@ static int pblk_line_submit_smeta_io(struct pblk *pblk, struct pblk_line *line,
 
 	memset(&rqd, 0, sizeof(struct nvm_rq));
 
-	rqd.ppa_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
-							&rqd.dma_ppa_list);
-	if (!rqd.ppa_list)
+	rqd.meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
+							&rqd.dma_meta_list);
+	if (!rqd.meta_list)
 		return -ENOMEM;
 
+	rqd.ppa_list = rqd.meta_list + pblk_dma_meta_size;
+	rqd.dma_ppa_list = rqd.dma_meta_list + pblk_dma_meta_size;
+
 	bio = bio_map_kern(dev->q, line->smeta, lm->smeta_len, GFP_KERNEL);
 	if (IS_ERR(bio)) {
 		ret = PTR_ERR(bio);
@@ -748,9 +761,15 @@ static int pblk_line_submit_smeta_io(struct pblk *pblk, struct pblk_line *line,
 	rqd.private = &wait;
 
 	for (i = 0; i < lm->smeta_sec; i++, paddr++) {
+		struct pblk_sec_meta *meta_list = rqd.meta_list;
+
 		rqd.ppa_list[i] = addr_to_gen_ppa(pblk, paddr, line->id);
-		if (dir == WRITE)
-			lba_list[paddr] = cpu_to_le64(ADDR_EMPTY);
+
+		if (dir == WRITE) {
+			u64 addr_empty = cpu_to_le64(ADDR_EMPTY);
+
+			meta_list[i].lba = lba_list[paddr] = addr_empty;
+		}
 	}
 
 	/*
@@ -778,7 +797,7 @@ static int pblk_line_submit_smeta_io(struct pblk *pblk, struct pblk_line *line,
 	}
 
 free_ppa_list:
-	nvm_dev_dma_free(dev->parent, rqd.ppa_list, rqd.dma_ppa_list);
+	nvm_dev_dma_free(dev->parent, rqd.meta_list, rqd.dma_meta_list);
 
 	return ret;
 }
diff --git a/drivers/lightnvm/pblk-read.c b/drivers/lightnvm/pblk-read.c
index d6499cdb7d33..292cbd290eea 100644
--- a/drivers/lightnvm/pblk-read.c
+++ b/drivers/lightnvm/pblk-read.c
@@ -123,8 +123,7 @@ static void pblk_end_io_read(struct nvm_rq *rqd)
 		WARN_ONCE(bio->bi_status, "pblk: corrupted read error\n");
 #endif
 
-	if (rqd->nr_ppas > 1)
-		nvm_dev_dma_free(dev->parent, rqd->ppa_list, rqd->dma_ppa_list);
+	nvm_dev_dma_free(dev->parent, rqd->meta_list, rqd->dma_meta_list);
 
 	bio_put(bio);
 	if (r_ctx->private) {
@@ -329,13 +328,16 @@ int pblk_submit_read(struct pblk *pblk, struct bio *bio)
 	 */
 	bio_init_idx = pblk_get_bi_idx(bio);
 
+	rqd->meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
+							&rqd->dma_meta_list);
+	if (!rqd->meta_list) {
+		pr_err("pblk: not able to allocate ppa list\n");
+		goto fail_rqd_free;
+	}
+
 	if (nr_secs > 1) {
-		rqd->ppa_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
-						&rqd->dma_ppa_list);
-		if (!rqd->ppa_list) {
-			pr_err("pblk: not able to allocate ppa list\n");
-			goto fail_rqd_free;
-		}
+		rqd->ppa_list = rqd->meta_list + pblk_dma_meta_size;
+		rqd->dma_ppa_list = rqd->dma_meta_list + pblk_dma_meta_size;
 
 		pblk_read_ppalist_rq(pblk, rqd, &read_bitmap);
 	} else {
@@ -466,22 +468,19 @@ int pblk_submit_read_gc(struct pblk *pblk, u64 *lba_list, void *data,
 
 	memset(&rqd, 0, sizeof(struct nvm_rq));
 
+	rqd.meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
+							&rqd.dma_meta_list);
+	if (!rqd.meta_list)
+		return NVM_IO_ERR;
+
 	if (nr_secs > 1) {
-		rqd.ppa_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
-							&rqd.dma_ppa_list);
-		if (!rqd.ppa_list)
-			return NVM_IO_ERR;
+		rqd.ppa_list = rqd.meta_list + pblk_dma_meta_size;
+		rqd.dma_ppa_list = rqd.dma_meta_list + pblk_dma_meta_size;
 
 		*secs_to_gc = read_ppalist_rq_gc(pblk, &rqd, line, lba_list,
 								nr_secs);
-		if (*secs_to_gc == 1) {
-			struct ppa_addr ppa;
-
-			ppa = rqd.ppa_list[0];
-			nvm_dev_dma_free(dev->parent, rqd.ppa_list,
-							rqd.dma_ppa_list);
-			rqd.ppa_addr = ppa;
-		}
+		if (*secs_to_gc == 1)
+			rqd.ppa_addr = rqd.ppa_list[0];
 	} else {
 		*secs_to_gc = read_rq_gc(pblk, &rqd, line, lba_list[0]);
 	}
@@ -532,12 +531,10 @@ int pblk_submit_read_gc(struct pblk *pblk, u64 *lba_list, void *data,
 #endif
 
 out:
-	if (rqd.nr_ppas > 1)
-		nvm_dev_dma_free(dev->parent, rqd.ppa_list, rqd.dma_ppa_list);
+	nvm_dev_dma_free(dev->parent, rqd.meta_list, rqd.dma_meta_list);
 	return NVM_IO_OK;
 
 err_free_dma:
-	if (rqd.nr_ppas > 1)
-		nvm_dev_dma_free(dev->parent, rqd.ppa_list, rqd.dma_ppa_list);
+	nvm_dev_dma_free(dev->parent, rqd.meta_list, rqd.dma_meta_list);
 	return NVM_IO_ERR;
 }
-- 
2.7.4

[PATCH 16/20] lightnvm: pblk: cleanup unnecessary code

[Javier González]

Cleanup unnecessary headers and code lines.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/pblk-core.c  | 1 -
 drivers/lightnvm/pblk-write.c | 6 ------
 2 files changed, 7 deletions(-)

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index cba7cd78e4a6..d815cdad56b8 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -17,7 +17,6 @@
  */
 
 #include "pblk.h"
-#include <linux/time.h>
 
 static void pblk_mark_bb(struct pblk *pblk, struct pblk_line *line,
 			 struct ppa_addr *ppa)
diff --git a/drivers/lightnvm/pblk-write.c b/drivers/lightnvm/pblk-write.c
index 3db2cbe5b788..a50bfbd12c32 100644
--- a/drivers/lightnvm/pblk-write.c
+++ b/drivers/lightnvm/pblk-write.c
@@ -27,14 +27,8 @@ static unsigned long pblk_end_w_bio(struct pblk *pblk, struct nvm_rq *rqd,
 
 	for (i = 0; i < c_ctx->nr_valid; i++) {
 		struct pblk_w_ctx *w_ctx;
-		struct ppa_addr p;
-		struct pblk_line *line;
 
 		w_ctx = pblk_rb_w_ctx(&pblk->rwb, c_ctx->sentry + i);
-
-		p = rqd->ppa_list[i];
-		line = &pblk->lines[pblk_dev_ppa_to_line(p)];
-
 		while ((original_bio = bio_list_pop(&w_ctx->bios)))
 			bio_endio(original_bio);
 	}
-- 
2.7.4

[PATCH 17/20] lightnvm: pblk: add lock assertions on helpers

[Javier González]

Add lockdep assertions on helper functions.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/pblk-core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index d815cdad56b8..ed41cd7700b3 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -295,6 +295,8 @@ struct list_head *pblk_line_gc_list(struct pblk *pblk, struct pblk_line *line)
 	struct list_head *move_list = NULL;
 	int vsc = le32_to_cpu(*line->vsc);
 
+	lockdep_assert_held(&line->lock);
+
 	if (!vsc) {
 		if (line->gc_group != PBLK_LINEGC_FULL) {
 			line->gc_group = PBLK_LINEGC_FULL;
@@ -502,6 +504,8 @@ u64 __pblk_alloc_page(struct pblk *pblk, struct pblk_line *line, int nr_secs)
 	u64 addr;
 	int i;
 
+	lockdep_assert_held(&line->lock);
+
 	/* logic error: ppa out-of-bounds. Prevent generating bad address */
 	if (line->cur_sec + nr_secs > pblk->lm.sec_per_line) {
 		WARN(1, "pblk: page allocation out of bounds\n");
-- 
2.7.4

[PATCH 18/20] lightnvm: pblk: redesign GC algorithm

[Javier González]

At the moment, in order to get enough read parallelism, we have recycled
several lines at the same time. This approach has proven not to work
well when reaching capacity, since we end up mixing valid data from all
lines, thus not maintaining a sustainable free/recycled line ratio.

The new design, relies on a two level workqueue mechanism. In the first
level, we read the metadata for a number of lines based on the GC list
they reside on (this is governed by the number of valid sectors in each
line). In the second level, we recycle a single line at a time. Here, we
issue reads in parallel, while a single GC write thread places data in
the write buffer. This design allows to (i) only move data from one line
at a time, thus maintaining a sane free/recycled ration and (ii)
maintain the GC writer busy with recycled data.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/pblk-core.c  |   7 +-
 drivers/lightnvm/pblk-gc.c    | 441 ++++++++++++++++++++++++------------------
 drivers/lightnvm/pblk-rb.c    |  21 +-
 drivers/lightnvm/pblk-rl.c    |  60 ++++--
 drivers/lightnvm/pblk-sysfs.c |  51 +----
 drivers/lightnvm/pblk.h       |  66 +++++--
 6 files changed, 368 insertions(+), 278 deletions(-)

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index ed41cd7700b3..ba3b88f0e1f7 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -302,12 +302,12 @@ struct list_head *pblk_line_gc_list(struct pblk *pblk, struct pblk_line *line)
 			line->gc_group = PBLK_LINEGC_FULL;
 			move_list = &l_mg->gc_full_list;
 		}
-	} else if (vsc < lm->mid_thrs) {
+	} else if (vsc < lm->high_thrs) {
 		if (line->gc_group != PBLK_LINEGC_HIGH) {
 			line->gc_group = PBLK_LINEGC_HIGH;
 			move_list = &l_mg->gc_high_list;
 		}
-	} else if (vsc < lm->high_thrs) {
+	} else if (vsc < lm->mid_thrs) {
 		if (line->gc_group != PBLK_LINEGC_MID) {
 			line->gc_group = PBLK_LINEGC_MID;
 			move_list = &l_mg->gc_mid_list;
@@ -1199,6 +1199,7 @@ struct pblk_line *pblk_line_get(struct pblk *pblk)
 	if (pblk_line_prepare(pblk, line)) {
 		pr_err("pblk: failed to prepare line %d\n", line->id);
 		list_add(&line->list, &l_mg->free_list);
+		l_mg->nr_free_lines++;
 		return NULL;
 	}
 
@@ -1465,6 +1466,8 @@ void pblk_line_close(struct pblk *pblk, struct pblk_line *line)
 
 	spin_unlock(&line->lock);
 	spin_unlock(&l_mg->gc_lock);
+
+	pblk_gc_should_kick(pblk);
 }
 
 void pblk_line_close_meta(struct pblk *pblk, struct pblk_line *line)
diff --git a/drivers/lightnvm/pblk-gc.c b/drivers/lightnvm/pblk-gc.c
index f811e4ca63f4..1d289242ab92 100644
--- a/drivers/lightnvm/pblk-gc.c
+++ b/drivers/lightnvm/pblk-gc.c
@@ -21,7 +21,6 @@
 static void pblk_gc_free_gc_rq(struct pblk_gc_rq *gc_rq)
 {
 	kfree(gc_rq->data);
-	kfree(gc_rq->lba_list);
 	kfree(gc_rq);
 }
 
@@ -37,10 +36,8 @@ static int pblk_gc_write(struct pblk *pblk)
 		return 1;
 	}
 
-	list_for_each_entry_safe(gc_rq, tgc_rq, &gc->w_list, list) {
-		list_move_tail(&gc_rq->list, &w_list);
-		gc->w_entries--;
-	}
+	list_cut_position(&w_list, &gc->w_list, gc->w_list.prev);
+	gc->w_entries = 0;
 	spin_unlock(&gc->w_lock);
 
 	list_for_each_entry_safe(gc_rq, tgc_rq, &w_list, list) {
@@ -48,9 +45,8 @@ static int pblk_gc_write(struct pblk *pblk)
 				gc_rq->nr_secs, gc_rq->secs_to_gc,
 				gc_rq->line, PBLK_IOTYPE_GC);
 
-		kref_put(&gc_rq->line->ref, pblk_line_put);
-
 		list_del(&gc_rq->list);
+		kref_put(&gc_rq->line->ref, pblk_line_put);
 		pblk_gc_free_gc_rq(gc_rq);
 	}
 
@@ -66,52 +62,41 @@ static void pblk_gc_writer_kick(struct pblk_gc *gc)
  * Responsible for managing all memory related to a gc request. Also in case of
  * failure
  */
-static int pblk_gc_move_valid_secs(struct pblk *pblk, struct pblk_line *line,
-				   u64 *lba_list, unsigned int nr_secs)
+static int pblk_gc_move_valid_secs(struct pblk *pblk, struct pblk_gc_rq *gc_rq)
 {
 	struct nvm_tgt_dev *dev = pblk->dev;
 	struct nvm_geo *geo = &dev->geo;
 	struct pblk_gc *gc = &pblk->gc;
-	struct pblk_gc_rq *gc_rq;
+	struct pblk_line *line = gc_rq->line;
 	void *data;
 	unsigned int secs_to_gc;
-	int ret = NVM_IO_OK;
+	int ret = 0;
 
-	data = kmalloc(nr_secs * geo->sec_size, GFP_KERNEL);
+	data = kmalloc(gc_rq->nr_secs * geo->sec_size, GFP_KERNEL);
 	if (!data) {
-		ret = NVM_IO_ERR;
-		goto free_lba_list;
+		ret = -ENOMEM;
+		goto out;
 	}
 
 	/* Read from GC victim block */
-	if (pblk_submit_read_gc(pblk, lba_list, data, nr_secs,
+	if (pblk_submit_read_gc(pblk, gc_rq->lba_list, data, gc_rq->nr_secs,
 							&secs_to_gc, line)) {
-		ret = NVM_IO_ERR;
+		ret = -EFAULT;
 		goto free_data;
 	}
 
 	if (!secs_to_gc)
-		goto free_data;
+		goto free_rq;
 
-	gc_rq = kmalloc(sizeof(struct pblk_gc_rq), GFP_KERNEL);
-	if (!gc_rq) {
-		ret = NVM_IO_ERR;
-		goto free_data;
-	}
-
-	gc_rq->line = line;
 	gc_rq->data = data;
-	gc_rq->lba_list = lba_list;
-	gc_rq->nr_secs = nr_secs;
 	gc_rq->secs_to_gc = secs_to_gc;
 
-	kref_get(&line->ref);
-
 retry:
 	spin_lock(&gc->w_lock);
-	if (gc->w_entries > 256) {
+	if (gc->w_entries >= PBLK_GC_W_QD) {
 		spin_unlock(&gc->w_lock);
-		usleep_range(256, 1024);
+		pblk_gc_writer_kick(&pblk->gc);
+		usleep_range(128, 256);
 		goto retry;
 	}
 	gc->w_entries++;
@@ -120,13 +105,14 @@ static int pblk_gc_move_valid_secs(struct pblk *pblk, struct pblk_line *line,
 
 	pblk_gc_writer_kick(&pblk->gc);
 
-	return NVM_IO_OK;
+	return 0;
 
+free_rq:
+	kfree(gc_rq);
 free_data:
 	kfree(data);
-free_lba_list:
-	kfree(lba_list);
-
+out:
+	kref_put(&line->ref, pblk_line_put);
 	return ret;
 }
 
@@ -150,20 +136,52 @@ static void pblk_put_line_back(struct pblk *pblk, struct pblk_line *line)
 
 static void pblk_gc_line_ws(struct work_struct *work)
 {
+	struct pblk_line_ws *line_rq_ws = container_of(work,
+						struct pblk_line_ws, ws);
+	struct pblk *pblk = line_rq_ws->pblk;
+	struct pblk_gc *gc = &pblk->gc;
+	struct pblk_line *line = line_rq_ws->line;
+	struct pblk_gc_rq *gc_rq = line_rq_ws->priv;
+
+	up(&gc->gc_sem);
+
+	if (pblk_gc_move_valid_secs(pblk, gc_rq)) {
+		pr_err("pblk: could not GC all sectors: line:%d (%d/%d)\n",
+						line->id, *line->vsc,
+						gc_rq->nr_secs);
+	}
+
+	mempool_free(line_rq_ws, pblk->line_ws_pool);
+}
+
+static void pblk_gc_line_prepare_ws(struct work_struct *work)
+{
 	struct pblk_line_ws *line_ws = container_of(work, struct pblk_line_ws,
 									ws);
 	struct pblk *pblk = line_ws->pblk;
-	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 	struct pblk_line *line = line_ws->line;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 	struct pblk_line_meta *lm = &pblk->lm;
-	struct line_emeta *emeta_buf = line_ws->priv;
+	struct pblk_gc *gc = &pblk->gc;
+	struct line_emeta *emeta_buf;
+	struct pblk_line_ws *line_rq_ws;
+	struct pblk_gc_rq *gc_rq;
 	__le64 *lba_list;
-	u64 *gc_list;
-	int sec_left;
-	int nr_ppas, bit;
-	int put_line = 1;
+	int sec_left, nr_secs, bit;
+	int ret;
 
-	pr_debug("pblk: line '%d' being reclaimed for GC\n", line->id);
+	emeta_buf = pblk_malloc(lm->emeta_len[0], l_mg->emeta_alloc_type,
+								GFP_KERNEL);
+	if (!emeta_buf) {
+		pr_err("pblk: cannot use GC emeta\n");
+		return;
+	}
+
+	ret = pblk_line_read_emeta(pblk, line, emeta_buf);
+	if (ret) {
+		pr_err("pblk: line %d read emeta failed (%d)\n", line->id, ret);
+		goto fail_free_emeta;
+	}
 
 	/* If this read fails, it means that emeta is corrupted. For now, leave
 	 * the line untouched. TODO: Implement a recovery routine that scans and
@@ -172,119 +190,124 @@ static void pblk_gc_line_ws(struct work_struct *work)
 	lba_list = pblk_recov_get_lba_list(pblk, emeta_buf);
 	if (!lba_list) {
 		pr_err("pblk: could not interpret emeta (line %d)\n", line->id);
-		goto out;
+		goto fail_free_emeta;
 	}
 
-	spin_lock(&line->lock);
-	sec_left = le32_to_cpu(*line->vsc);
-	if (!sec_left) {
-		/* Lines are erased before being used (l_mg->data_/log_next) */
-		spin_unlock(&line->lock);
-		goto out;
-	}
-	spin_unlock(&line->lock);
-
+	sec_left = pblk_line_vsc(line);
 	if (sec_left < 0) {
 		pr_err("pblk: corrupted GC line (%d)\n", line->id);
-		put_line = 0;
-		pblk_put_line_back(pblk, line);
-		goto out;
+		goto fail_free_emeta;
 	}
 
 	bit = -1;
 next_rq:
-	gc_list = kmalloc_array(pblk->max_write_pgs, sizeof(u64), GFP_KERNEL);
-	if (!gc_list) {
-		put_line = 0;
-		pblk_put_line_back(pblk, line);
-		goto out;
-	}
+	gc_rq = kmalloc(sizeof(struct pblk_gc_rq), GFP_KERNEL);
+	if (!gc_rq)
+		goto fail_free_emeta;
 
-	nr_ppas = 0;
+	nr_secs = 0;
 	do {
 		bit = find_next_zero_bit(line->invalid_bitmap, lm->sec_per_line,
 								bit + 1);
 		if (bit > line->emeta_ssec)
 			break;
 
-		gc_list[nr_ppas++] = le64_to_cpu(lba_list[bit]);
-	} while (nr_ppas < pblk->max_write_pgs);
+		gc_rq->lba_list[nr_secs++] = le64_to_cpu(lba_list[bit]);
+	} while (nr_secs < pblk->max_write_pgs);
 
-	if (unlikely(!nr_ppas)) {
-		kfree(gc_list);
+	if (unlikely(!nr_secs)) {
+		kfree(gc_rq);
 		goto out;
 	}
 
-	if (pblk_gc_move_valid_secs(pblk, line, gc_list, nr_ppas)) {
-		pr_err("pblk: could not GC all sectors: line:%d (%d/%d/%d)\n",
-						line->id, *line->vsc,
-						nr_ppas, nr_ppas);
-		put_line = 0;
-		pblk_put_line_back(pblk, line);
-		goto out;
-	}
+	gc_rq->nr_secs = nr_secs;
+	gc_rq->line = line;
+
+	line_rq_ws = mempool_alloc(pblk->line_ws_pool, GFP_KERNEL);
+	if (!line_rq_ws)
+		goto fail_free_gc_rq;
+
+	line_rq_ws->pblk = pblk;
+	line_rq_ws->line = line;
+	line_rq_ws->priv = gc_rq;
+
+	down(&gc->gc_sem);
+	kref_get(&line->ref);
+
+	INIT_WORK(&line_rq_ws->ws, pblk_gc_line_ws);
+	queue_work(gc->gc_line_reader_wq, &line_rq_ws->ws);
 
-	sec_left -= nr_ppas;
+	sec_left -= nr_secs;
 	if (sec_left > 0)
 		goto next_rq;
 
 out:
 	pblk_mfree(emeta_buf, l_mg->emeta_alloc_type);
 	mempool_free(line_ws, pblk->line_ws_pool);
-	atomic_dec(&pblk->gc.inflight_gc);
-	if (put_line)
-		kref_put(&line->ref, pblk_line_put);
+
+	kref_put(&line->ref, pblk_line_put);
+	atomic_dec(&gc->inflight_gc);
+
+	return;
+
+fail_free_gc_rq:
+	kfree(gc_rq);
+fail_free_emeta:
+	pblk_mfree(emeta_buf, l_mg->emeta_alloc_type);
+	pblk_put_line_back(pblk, line);
+	kref_put(&line->ref, pblk_line_put);
+	mempool_free(line_ws, pblk->line_ws_pool);
+	atomic_dec(&gc->inflight_gc);
+
+	pr_err("pblk: Failed to GC line %d\n", line->id);
 }
 
 static int pblk_gc_line(struct pblk *pblk, struct pblk_line *line)
 {
-	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
-	struct pblk_line_meta *lm = &pblk->lm;
-	struct line_emeta *emeta_buf;
+	struct pblk_gc *gc = &pblk->gc;
 	struct pblk_line_ws *line_ws;
-	int ret;
+
+	pr_debug("pblk: line '%d' being reclaimed for GC\n", line->id);
 
 	line_ws = mempool_alloc(pblk->line_ws_pool, GFP_KERNEL);
-	emeta_buf = pblk_malloc(lm->emeta_len[0], l_mg->emeta_alloc_type,
-								GFP_KERNEL);
-	if (!emeta_buf) {
-		pr_err("pblk: cannot use GC emeta\n");
-		goto fail_free_ws;
-	}
-
-	ret = pblk_line_read_emeta(pblk, line, emeta_buf);
-	if (ret) {
-		pr_err("pblk: line %d read emeta failed (%d)\n", line->id, ret);
-		goto fail_free_emeta;
-	}
+	if (!line_ws)
+		return -ENOMEM;
 
 	line_ws->pblk = pblk;
 	line_ws->line = line;
-	line_ws->priv = emeta_buf;
 
-	INIT_WORK(&line_ws->ws, pblk_gc_line_ws);
-	queue_work(pblk->gc.gc_reader_wq, &line_ws->ws);
+	INIT_WORK(&line_ws->ws, pblk_gc_line_prepare_ws);
+	queue_work(gc->gc_reader_wq, &line_ws->ws);
 
 	return 0;
-
-fail_free_emeta:
-	pblk_mfree(emeta_buf, l_mg->emeta_alloc_type);
-fail_free_ws:
-	mempool_free(line_ws, pblk->line_ws_pool);
-	pblk_put_line_back(pblk, line);
-
-	return 1;
 }
 
-static void pblk_gc_lines(struct pblk *pblk, struct list_head *gc_list)
+static int pblk_gc_read(struct pblk *pblk)
 {
-	struct pblk_line *line, *tline;
+	struct pblk_gc *gc = &pblk->gc;
+	struct pblk_line *line;
 
-	list_for_each_entry_safe(line, tline, gc_list, list) {
-		if (pblk_gc_line(pblk, line))
-			pr_err("pblk: failed to GC line %d\n", line->id);
-		list_del(&line->list);
+	spin_lock(&gc->r_lock);
+	if (list_empty(&gc->r_list)) {
+		spin_unlock(&gc->r_lock);
+		return 1;
 	}
+
+	line = list_first_entry(&gc->r_list, struct pblk_line, list);
+	list_del(&line->list);
+	spin_unlock(&gc->r_lock);
+
+	pblk_gc_kick(pblk);
+
+	if (pblk_gc_line(pblk, line))
+		pr_err("pblk: failed to GC line %d\n", line->id);
+
+	return 0;
+}
+
+static void pblk_gc_reader_kick(struct pblk_gc *gc)
+{
+	wake_up_process(gc->gc_reader_ts);
 }
 
 static struct pblk_line *pblk_gc_get_victim_line(struct pblk *pblk,
@@ -301,6 +324,17 @@ static struct pblk_line *pblk_gc_get_victim_line(struct pblk *pblk,
 	return victim;
 }
 
+static bool pblk_gc_should_run(struct pblk_gc *gc, struct pblk_rl *rl)
+{
+	unsigned int nr_blocks_free, nr_blocks_need;
+
+	nr_blocks_need = pblk_rl_high_thrs(rl);
+	nr_blocks_free = pblk_rl_nr_free_blks(rl);
+
+	/* This is not critical, no need to take lock here */
+	return ((gc->gc_active) && (nr_blocks_need > nr_blocks_free));
+}
+
 /*
  * Lines with no valid sectors will be returned to the free list immediately. If
  * GC is activated - either because the free block count is under the determined
@@ -311,71 +345,83 @@ static void pblk_gc_run(struct pblk *pblk)
 {
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 	struct pblk_gc *gc = &pblk->gc;
-	struct pblk_line *line, *tline;
-	unsigned int nr_blocks_free, nr_blocks_need;
+	struct pblk_line *line;
 	struct list_head *group_list;
-	int run_gc, gc_group = 0;
-	int prev_gc = 0;
-	int inflight_gc = atomic_read(&gc->inflight_gc);
-	LIST_HEAD(gc_list);
+	bool run_gc;
+	int inflight_gc, gc_group = 0, prev_group = 0;
+
+	do {
+		spin_lock(&l_mg->gc_lock);
+		if (list_empty(&l_mg->gc_full_list)) {
+			spin_unlock(&l_mg->gc_lock);
+			break;
+		}
+
+		line = list_first_entry(&l_mg->gc_full_list,
+							struct pblk_line, list);
 
-	spin_lock(&l_mg->gc_lock);
-	list_for_each_entry_safe(line, tline, &l_mg->gc_full_list, list) {
 		spin_lock(&line->lock);
 		WARN_ON(line->state != PBLK_LINESTATE_CLOSED);
 		line->state = PBLK_LINESTATE_GC;
 		spin_unlock(&line->lock);
 
 		list_del(&line->list);
+		spin_unlock(&l_mg->gc_lock);
+
 		kref_put(&line->ref, pblk_line_put);
-	}
-	spin_unlock(&l_mg->gc_lock);
+	} while (1);
 
-	nr_blocks_need = pblk_rl_gc_thrs(&pblk->rl);
-	nr_blocks_free = pblk_rl_nr_free_blks(&pblk->rl);
-	run_gc = (nr_blocks_need > nr_blocks_free || gc->gc_forced);
+	run_gc = pblk_gc_should_run(&pblk->gc, &pblk->rl);
+	if (!run_gc || (atomic_read(&gc->inflight_gc) >= PBLK_GC_L_QD))
+		return;
 
 next_gc_group:
 	group_list = l_mg->gc_lists[gc_group++];
-	spin_lock(&l_mg->gc_lock);
-	while (run_gc && !list_empty(group_list)) {
-		/* No need to queue up more GC lines than we can handle */
-		if (!run_gc || inflight_gc > gc->gc_jobs_active) {
+
+	do {
+		spin_lock(&l_mg->gc_lock);
+		if (list_empty(group_list)) {
 			spin_unlock(&l_mg->gc_lock);
-			pblk_gc_lines(pblk, &gc_list);
-			return;
+			break;
 		}
 
 		line = pblk_gc_get_victim_line(pblk, group_list);
-		nr_blocks_free += atomic_read(&line->blk_in_line);
 
 		spin_lock(&line->lock);
 		WARN_ON(line->state != PBLK_LINESTATE_CLOSED);
 		line->state = PBLK_LINESTATE_GC;
-		list_move_tail(&line->list, &gc_list);
-		atomic_inc(&gc->inflight_gc);
-		inflight_gc++;
 		spin_unlock(&line->lock);
 
-		prev_gc = 1;
-		run_gc = (nr_blocks_need > nr_blocks_free || gc->gc_forced);
-	}
-	spin_unlock(&l_mg->gc_lock);
+		list_del(&line->list);
+		spin_unlock(&l_mg->gc_lock);
 
-	pblk_gc_lines(pblk, &gc_list);
+		spin_lock(&gc->r_lock);
+		list_add_tail(&line->list, &gc->r_list);
+		spin_unlock(&gc->r_lock);
 
-	if (!prev_gc && pblk->rl.rb_state > gc_group &&
-						gc_group < PBLK_NR_GC_LISTS)
+		inflight_gc = atomic_inc_return(&gc->inflight_gc);
+		pblk_gc_reader_kick(gc);
+
+		prev_group = 1;
+
+		/* No need to queue up more GC lines than we can handle */
+		run_gc = pblk_gc_should_run(&pblk->gc, &pblk->rl);
+		if (!run_gc || inflight_gc >= PBLK_GC_L_QD)
+			break;
+	} while (1);
+
+	if (!prev_group && pblk->rl.rb_state > gc_group &&
+						gc_group < PBLK_GC_NR_LISTS)
 		goto next_gc_group;
 }
 
-
-static void pblk_gc_kick(struct pblk *pblk)
+void pblk_gc_kick(struct pblk *pblk)
 {
 	struct pblk_gc *gc = &pblk->gc;
 
 	wake_up_process(gc->gc_ts);
 	pblk_gc_writer_kick(gc);
+	pblk_gc_reader_kick(gc);
 	mod_timer(&gc->gc_timer, jiffies + msecs_to_jiffies(GC_TIME_MSECS));
 }
 
@@ -413,42 +459,34 @@ static int pblk_gc_writer_ts(void *data)
 	return 0;
 }
 
+static int pblk_gc_reader_ts(void *data)
+{
+	struct pblk *pblk = data;
+
+	while (!kthread_should_stop()) {
+		if (!pblk_gc_read(pblk))
+			continue;
+		set_current_state(TASK_INTERRUPTIBLE);
+		io_schedule();
+	}
+
+	return 0;
+}
+
 static void pblk_gc_start(struct pblk *pblk)
 {
 	pblk->gc.gc_active = 1;
-
 	pr_debug("pblk: gc start\n");
 }
 
-int pblk_gc_status(struct pblk *pblk)
+void pblk_gc_should_start(struct pblk *pblk)
 {
 	struct pblk_gc *gc = &pblk->gc;
-	int ret;
-
-	spin_lock(&gc->lock);
-	ret = gc->gc_active;
-	spin_unlock(&gc->lock);
-
-	return ret;
-}
-
-static void __pblk_gc_should_start(struct pblk *pblk)
-{
-	struct pblk_gc *gc = &pblk->gc;
-
-	lockdep_assert_held(&gc->lock);
 
 	if (gc->gc_enabled && !gc->gc_active)
 		pblk_gc_start(pblk);
-}
 
-void pblk_gc_should_start(struct pblk *pblk)
-{
-	struct pblk_gc *gc = &pblk->gc;
-
-	spin_lock(&gc->lock);
-	__pblk_gc_should_start(pblk);
-	spin_unlock(&gc->lock);
+	pblk_gc_kick(pblk);
 }
 
 /*
@@ -457,10 +495,7 @@ void pblk_gc_should_start(struct pblk *pblk)
  */
 static void pblk_gc_stop(struct pblk *pblk, int flush_wq)
 {
-	spin_lock(&pblk->gc.lock);
 	pblk->gc.gc_active = 0;
-	spin_unlock(&pblk->gc.lock);
-
 	pr_debug("pblk: gc stop\n");
 }
 
@@ -483,20 +518,25 @@ void pblk_gc_sysfs_state_show(struct pblk *pblk, int *gc_enabled,
 	spin_unlock(&gc->lock);
 }
 
-void pblk_gc_sysfs_force(struct pblk *pblk, int force)
+int pblk_gc_sysfs_force(struct pblk *pblk, int force)
 {
 	struct pblk_gc *gc = &pblk->gc;
-	int rsv = 0;
+
+	if (force < 0 || force > 1)
+		return -EINVAL;
 
 	spin_lock(&gc->lock);
-	if (force) {
-		gc->gc_enabled = 1;
-		rsv = 64;
-	}
-	pblk_rl_set_gc_rsc(&pblk->rl, rsv);
 	gc->gc_forced = force;
-	__pblk_gc_should_start(pblk);
+
+	if (force)
+		gc->gc_enabled = 1;
+	else
+		gc->gc_enabled = 0;
 	spin_unlock(&gc->lock);
+
+	pblk_gc_should_start(pblk);
+
+	return 0;
 }
 
 int pblk_gc_init(struct pblk *pblk)
@@ -518,30 +558,58 @@ int pblk_gc_init(struct pblk *pblk)
 		goto fail_free_main_kthread;
 	}
 
+	gc->gc_reader_ts = kthread_create(pblk_gc_reader_ts, pblk,
+							"pblk-gc-reader-ts");
+	if (IS_ERR(gc->gc_reader_ts)) {
+		pr_err("pblk: could not allocate GC reader kthread\n");
+		ret = PTR_ERR(gc->gc_reader_ts);
+		goto fail_free_writer_kthread;
+	}
+
 	setup_timer(&gc->gc_timer, pblk_gc_timer, (unsigned long)pblk);
 	mod_timer(&gc->gc_timer, jiffies + msecs_to_jiffies(GC_TIME_MSECS));
 
 	gc->gc_active = 0;
 	gc->gc_forced = 0;
 	gc->gc_enabled = 1;
-	gc->gc_jobs_active = 8;
 	gc->w_entries = 0;
 	atomic_set(&gc->inflight_gc, 0);
 
-	gc->gc_reader_wq = alloc_workqueue("pblk-gc-reader-wq",
-			WQ_MEM_RECLAIM | WQ_UNBOUND, gc->gc_jobs_active);
+	/* Workqueue that reads valid sectors from a line and submit them to the
+	 * GC writer to be recycled.
+	 */
+	gc->gc_line_reader_wq = alloc_workqueue("pblk-gc-line-reader-wq",
+			WQ_MEM_RECLAIM | WQ_UNBOUND, PBLK_GC_MAX_READERS);
+	if (!gc->gc_line_reader_wq) {
+		pr_err("pblk: could not allocate GC line reader workqueue\n");
+		ret = -ENOMEM;
+		goto fail_free_reader_kthread;
+	}
+
+	/* Workqueue that prepare lines for GC */
+	gc->gc_reader_wq = alloc_workqueue("pblk-gc-line_wq",
+					WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
 	if (!gc->gc_reader_wq) {
 		pr_err("pblk: could not allocate GC reader workqueue\n");
 		ret = -ENOMEM;
-		goto fail_free_writer_kthread;
+		goto fail_free_reader_line_wq;
 	}
 
 	spin_lock_init(&gc->lock);
 	spin_lock_init(&gc->w_lock);
+	spin_lock_init(&gc->r_lock);
+
+	sema_init(&gc->gc_sem, 128);
+
 	INIT_LIST_HEAD(&gc->w_list);
+	INIT_LIST_HEAD(&gc->r_list);
 
 	return 0;
 
+fail_free_reader_line_wq:
+	destroy_workqueue(gc->gc_line_reader_wq);
+fail_free_reader_kthread:
+	kthread_stop(gc->gc_reader_ts);
 fail_free_writer_kthread:
 	kthread_stop(gc->gc_writer_ts);
 fail_free_main_kthread:
@@ -555,6 +623,7 @@ void pblk_gc_exit(struct pblk *pblk)
 	struct pblk_gc *gc = &pblk->gc;
 
 	flush_workqueue(gc->gc_reader_wq);
+	flush_workqueue(gc->gc_line_reader_wq);
 
 	del_timer(&gc->gc_timer);
 	pblk_gc_stop(pblk, 1);
@@ -562,9 +631,15 @@ void pblk_gc_exit(struct pblk *pblk)
 	if (gc->gc_ts)
 		kthread_stop(gc->gc_ts);
 
-	if (pblk->gc.gc_reader_wq)
-		destroy_workqueue(pblk->gc.gc_reader_wq);
+	if (gc->gc_reader_wq)
+		destroy_workqueue(gc->gc_reader_wq);
+
+	if (gc->gc_line_reader_wq)
+		destroy_workqueue(gc->gc_line_reader_wq);
 
 	if (gc->gc_writer_ts)
 		kthread_stop(gc->gc_writer_ts);
+
+	if (gc->gc_reader_ts)
+		kthread_stop(gc->gc_reader_ts);
 }
diff --git a/drivers/lightnvm/pblk-rb.c b/drivers/lightnvm/pblk-rb.c
index d293af12aa7a..50886878568b 100644
--- a/drivers/lightnvm/pblk-rb.c
+++ b/drivers/lightnvm/pblk-rb.c
@@ -199,12 +199,22 @@ static int __pblk_rb_update_l2p(struct pblk_rb *rb, unsigned int *l2p_upd,
 	struct pblk_line *line;
 	struct pblk_rb_entry *entry;
 	struct pblk_w_ctx *w_ctx;
+	unsigned int user_io = 0, gc_io = 0;
 	unsigned int i;
+	int flags;
 
 	for (i = 0; i < to_update; i++) {
 		entry = &rb->entries[*l2p_upd];
 		w_ctx = &entry->w_ctx;
 
+		flags = READ_ONCE(entry->w_ctx.flags);
+		if (flags & PBLK_IOTYPE_USER)
+			user_io++;
+		else if (flags & PBLK_IOTYPE_GC)
+			gc_io++;
+		else
+			WARN(1, "pblk: unknown IO type\n");
+
 		pblk_update_map_dev(pblk, w_ctx->lba, w_ctx->ppa,
 							entry->cacheline);
 
@@ -214,6 +224,8 @@ static int __pblk_rb_update_l2p(struct pblk_rb *rb, unsigned int *l2p_upd,
 		*l2p_upd = (*l2p_upd + 1) & (rb->nr_entries - 1);
 	}
 
+	pblk_rl_out(&pblk->rl, user_io, gc_io);
+
 	return 0;
 }
 
@@ -531,7 +543,6 @@ unsigned int pblk_rb_read_to_bio(struct pblk_rb *rb, struct nvm_rq *rqd,
 	struct pblk_rb_entry *entry;
 	struct page *page;
 	unsigned int pad = 0, to_read = nr_entries;
-	unsigned int user_io = 0, gc_io = 0;
 	unsigned int i;
 	int flags;
 
@@ -555,13 +566,6 @@ unsigned int pblk_rb_read_to_bio(struct pblk_rb *rb, struct nvm_rq *rqd,
 		if (!(flags & PBLK_WRITTEN_DATA))
 			goto try;
 
-		if (flags & PBLK_IOTYPE_USER)
-			user_io++;
-		else if (flags & PBLK_IOTYPE_GC)
-			gc_io++;
-		else
-			WARN(1, "pblk: unknown IO type\n");
-
 		page = virt_to_page(entry->data);
 		if (!page) {
 			pr_err("pblk: could not allocate write bio page\n");
@@ -613,7 +617,6 @@ unsigned int pblk_rb_read_to_bio(struct pblk_rb *rb, struct nvm_rq *rqd,
 		}
 	}
 
-	pblk_rl_out(&pblk->rl, user_io, gc_io);
 #ifdef CONFIG_NVM_DEBUG
 	atomic_long_add(pad, &((struct pblk *)
 			(container_of(rb, struct pblk, rwb)))->padded_writes);
diff --git a/drivers/lightnvm/pblk-rl.c b/drivers/lightnvm/pblk-rl.c
index ab7cbb144f3f..52068a1807a8 100644
--- a/drivers/lightnvm/pblk-rl.c
+++ b/drivers/lightnvm/pblk-rl.c
@@ -27,7 +27,7 @@ int pblk_rl_user_may_insert(struct pblk_rl *rl, int nr_entries)
 {
 	int rb_user_cnt = atomic_read(&rl->rb_user_cnt);
 
-	return (!(rb_user_cnt + nr_entries > rl->rb_user_max));
+	return (!(rb_user_cnt >= rl->rb_user_max));
 }
 
 int pblk_rl_gc_may_insert(struct pblk_rl *rl, int nr_entries)
@@ -37,7 +37,7 @@ int pblk_rl_gc_may_insert(struct pblk_rl *rl, int nr_entries)
 
 	/* If there is no user I/O let GC take over space on the write buffer */
 	rb_user_active = READ_ONCE(rl->rb_user_active);
-	return (!(rb_gc_cnt + nr_entries > rl->rb_gc_max && rb_user_active));
+	return (!(rb_gc_cnt >= rl->rb_gc_max && rb_user_active));
 }
 
 void pblk_rl_user_in(struct pblk_rl *rl, int nr_entries)
@@ -77,33 +77,32 @@ static int pblk_rl_update_rates(struct pblk_rl *rl, unsigned long max)
 	unsigned long free_blocks = pblk_rl_nr_free_blks(rl);
 
 	if (free_blocks >= rl->high) {
-		rl->rb_user_max = max - rl->rb_gc_rsv;
-		rl->rb_gc_max = rl->rb_gc_rsv;
+		rl->rb_user_max = max;
+		rl->rb_gc_max = 0;
 		rl->rb_state = PBLK_RL_HIGH;
 	} else if (free_blocks < rl->high) {
 		int shift = rl->high_pw - rl->rb_windows_pw;
 		int user_windows = free_blocks >> shift;
 		int user_max = user_windows << PBLK_MAX_REQ_ADDRS_PW;
-		int gc_max;
 
 		rl->rb_user_max = user_max;
-		gc_max = max - rl->rb_user_max;
-		rl->rb_gc_max = max(gc_max, rl->rb_gc_rsv);
+		rl->rb_gc_max = max - user_max;
 
-		if (free_blocks > rl->low)
-			rl->rb_state = PBLK_RL_MID;
-		else
-			rl->rb_state = PBLK_RL_LOW;
+		if (free_blocks <= rl->rsv_blocks) {
+			rl->rb_user_max = 0;
+			rl->rb_gc_max = max;
+		}
+
+		/* In the worst case, we will need to GC lines in the low list
+		 * (high valid sector count). If there are lines to GC on high
+		 * or mid lists, these will be prioritized
+		 */
+		rl->rb_state = PBLK_RL_LOW;
 	}
 
 	return rl->rb_state;
 }
 
-void pblk_rl_set_gc_rsc(struct pblk_rl *rl, int rsv)
-{
-	rl->rb_gc_rsv = rl->rb_gc_max = rsv;
-}
-
 void pblk_rl_free_lines_inc(struct pblk_rl *rl, struct pblk_line *line)
 {
 	struct pblk *pblk = container_of(rl, struct pblk, rl);
@@ -122,11 +121,15 @@ void pblk_rl_free_lines_inc(struct pblk_rl *rl, struct pblk_line *line)
 
 void pblk_rl_free_lines_dec(struct pblk_rl *rl, struct pblk_line *line)
 {
-	struct pblk *pblk = container_of(rl, struct pblk, rl);
 	int blk_in_line = atomic_read(&line->blk_in_line);
-	int ret;
 
 	atomic_sub(blk_in_line, &rl->free_blocks);
+}
+
+void pblk_gc_should_kick(struct pblk *pblk)
+{
+	struct pblk_rl *rl = &pblk->rl;
+	int ret;
 
 	/* Rates will not change that often - no need to lock update */
 	ret = pblk_rl_update_rates(rl, rl->rb_budget);
@@ -136,11 +139,16 @@ void pblk_rl_free_lines_dec(struct pblk_rl *rl, struct pblk_line *line)
 		pblk_gc_should_stop(pblk);
 }
 
-int pblk_rl_gc_thrs(struct pblk_rl *rl)
+int pblk_rl_high_thrs(struct pblk_rl *rl)
 {
 	return rl->high;
 }
 
+int pblk_rl_low_thrs(struct pblk_rl *rl)
+{
+	return rl->low;
+}
+
 int pblk_rl_sysfs_rate_show(struct pblk_rl *rl)
 {
 	return rl->rb_user_max;
@@ -161,15 +169,23 @@ void pblk_rl_free(struct pblk_rl *rl)
 
 void pblk_rl_init(struct pblk_rl *rl, int budget)
 {
+	struct pblk *pblk = container_of(rl, struct pblk, rl);
+	struct pblk_line_meta *lm = &pblk->lm;
+	int min_blocks = lm->blk_per_line * PBLK_GC_RSV_LINE;
 	unsigned int rb_windows;
 
 	rl->high = rl->total_blocks / PBLK_USER_HIGH_THRS;
-	rl->low = rl->total_blocks / PBLK_USER_LOW_THRS;
 	rl->high_pw = get_count_order(rl->high);
 
+	rl->low = rl->total_blocks / PBLK_USER_LOW_THRS;
+	if (rl->low < min_blocks)
+		rl->low = min_blocks;
+
+	rl->rsv_blocks = min_blocks;
+
 	/* This will always be a power-of-2 */
 	rb_windows = budget / PBLK_MAX_REQ_ADDRS;
-	rl->rb_windows_pw = get_count_order(rb_windows) + 1;
+	rl->rb_windows_pw = get_count_order(rb_windows);
 
 	/* To start with, all buffer is available to user I/O writers */
 	rl->rb_budget = budget;
@@ -180,5 +196,7 @@ void pblk_rl_init(struct pblk_rl *rl, int budget)
 	atomic_set(&rl->rb_gc_cnt, 0);
 
 	setup_timer(&rl->u_timer, pblk_rl_u_timer, (unsigned long)rl);
+
 	rl->rb_user_active = 0;
+	rl->rb_gc_active = 0;
 }
diff --git a/drivers/lightnvm/pblk-sysfs.c b/drivers/lightnvm/pblk-sysfs.c
index e1e92c9498a9..d9f7f13a38cc 100644
--- a/drivers/lightnvm/pblk-sysfs.c
+++ b/drivers/lightnvm/pblk-sysfs.c
@@ -49,30 +49,26 @@ static ssize_t pblk_sysfs_luns_show(struct pblk *pblk, char *page)
 
 static ssize_t pblk_sysfs_rate_limiter(struct pblk *pblk, char *page)
 {
-	struct nvm_tgt_dev *dev = pblk->dev;
-	struct nvm_geo *geo = &dev->geo;
 	int free_blocks, total_blocks;
 	int rb_user_max, rb_user_cnt;
-	int rb_gc_max, rb_gc_rsv, rb_gc_cnt, rb_budget, rb_state;
+	int rb_gc_max, rb_gc_cnt, rb_budget, rb_state;
 
 	free_blocks = atomic_read(&pblk->rl.free_blocks);
 	rb_user_max = pblk->rl.rb_user_max;
 	rb_user_cnt = atomic_read(&pblk->rl.rb_user_cnt);
 	rb_gc_max = pblk->rl.rb_gc_max;
-	rb_gc_rsv = pblk->rl.rb_gc_rsv;
 	rb_gc_cnt = atomic_read(&pblk->rl.rb_gc_cnt);
 	rb_budget = pblk->rl.rb_budget;
 	rb_state = pblk->rl.rb_state;
 
-	total_blocks = geo->blks_per_lun * geo->nr_luns;
+	total_blocks = pblk->rl.total_blocks;
 
 	return snprintf(page, PAGE_SIZE,
-		"u:%u/%u,gc:%u/%u/%u(%u/%u)(stop:<%u,full:>%u,free:%d/%d)-%d\n",
+		"u:%u/%u,gc:%u/%u(%u/%u)(stop:<%u,full:>%u,free:%d/%d)-%d\n",
 				rb_user_cnt,
 				rb_user_max,
 				rb_gc_cnt,
 				rb_gc_max,
-				rb_gc_rsv,
 				rb_state,
 				rb_budget,
 				pblk->rl.low,
@@ -237,7 +233,8 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page)
 	spin_unlock(&l_mg->free_lock);
 
 	if (nr_free_lines != free_line_cnt)
-		pr_err("pblk: corrupted free line list\n");
+		pr_err("pblk: corrupted free line list:%d/%d\n",
+						nr_free_lines, free_line_cnt);
 
 	sz = snprintf(page, PAGE_SIZE - sz,
 		"line: nluns:%d, nblks:%d, nsecs:%d\n",
@@ -319,32 +316,11 @@ static ssize_t pblk_sysfs_stats_debug(struct pblk *pblk, char *page)
 }
 #endif
 
-static ssize_t pblk_sysfs_rate_store(struct pblk *pblk, const char *page,
-				     size_t len)
-{
-	struct pblk_gc *gc = &pblk->gc;
-	size_t c_len;
-	int value;
-
-	c_len = strcspn(page, "\n");
-	if (c_len >= len)
-		return -EINVAL;
-
-	if (kstrtouint(page, 0, &value))
-		return -EINVAL;
-
-	spin_lock(&gc->lock);
-	pblk_rl_set_gc_rsc(&pblk->rl, value);
-	spin_unlock(&gc->lock);
-
-	return len;
-}
-
 static ssize_t pblk_sysfs_gc_force(struct pblk *pblk, const char *page,
 				   size_t len)
 {
 	size_t c_len;
-	int force;
+	int ret, force;
 
 	c_len = strcspn(page, "\n");
 	if (c_len >= len)
@@ -353,10 +329,7 @@ static ssize_t pblk_sysfs_gc_force(struct pblk *pblk, const char *page,
 	if (kstrtouint(page, 0, &force))
 		return -EINVAL;
 
-	if (force < 0 || force > 1)
-		return -EINVAL;
-
-	pblk_gc_sysfs_force(pblk, force);
+	ret = pblk_gc_sysfs_force(pblk, force);
 
 	return len;
 }
@@ -434,11 +407,6 @@ static struct attribute sys_max_sec_per_write = {
 	.mode = 0644,
 };
 
-static struct attribute sys_gc_rl_max = {
-	.name = "gc_rl_max",
-	.mode = 0200,
-};
-
 #ifdef CONFIG_NVM_DEBUG
 static struct attribute sys_stats_debug_attr = {
 	.name = "stats",
@@ -453,7 +421,6 @@ static struct attribute *pblk_attrs[] = {
 	&sys_gc_state,
 	&sys_gc_force,
 	&sys_max_sec_per_write,
-	&sys_gc_rl_max,
 	&sys_rb_attr,
 	&sys_stats_ppaf_attr,
 	&sys_lines_attr,
@@ -499,9 +466,7 @@ static ssize_t pblk_sysfs_store(struct kobject *kobj, struct attribute *attr,
 {
 	struct pblk *pblk = container_of(kobj, struct pblk, kobj);
 
-	if (strcmp(attr->name, "gc_rl_max") == 0)
-		return pblk_sysfs_rate_store(pblk, buf, len);
-	else if (strcmp(attr->name, "gc_force") == 0)
+	if (strcmp(attr->name, "gc_force") == 0)
 		return pblk_sysfs_gc_force(pblk, buf, len);
 	else if (strcmp(attr->name, "max_sec_per_write") == 0)
 		return pblk_sysfs_set_sec_per_write(pblk, buf, len);
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index 6c8d01198e8b..aaee718f1029 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -72,11 +72,15 @@ enum {
 	PBLK_BLK_ST_CLOSED =	0x2,
 };
 
+struct pblk_sec_meta {
+	u64 reserved;
+	__le64 lba;
+};
+
 /* The number of GC lists and the rate-limiter states go together. This way the
  * rate-limiter can dictate how much GC is needed based on resource utilization.
  */
-#define PBLK_NR_GC_LISTS 3
-#define PBLK_MAX_GC_JOBS 32
+#define PBLK_GC_NR_LISTS 3
 
 enum {
 	PBLK_RL_HIGH = 1,
@@ -84,11 +88,6 @@ enum {
 	PBLK_RL_LOW = 3,
 };
 
-struct pblk_sec_meta {
-	u64 reserved;
-	__le64 lba;
-};
-
 #define pblk_dma_meta_size (sizeof(struct pblk_sec_meta) * PBLK_MAX_REQ_ADDRS)
 
 /* write buffer completion context */
@@ -195,29 +194,39 @@ struct pblk_lun {
 struct pblk_gc_rq {
 	struct pblk_line *line;
 	void *data;
-	u64 *lba_list;
+	u64 lba_list[PBLK_MAX_REQ_ADDRS];
 	int nr_secs;
 	int secs_to_gc;
 	struct list_head list;
 };
 
 struct pblk_gc {
+	/* These states are not protected by a lock since (i) they are in the
+	 * fast path, and (ii) they are not critical.
+	 */
 	int gc_active;
 	int gc_enabled;
 	int gc_forced;
-	int gc_jobs_active;
-	atomic_t inflight_gc;
 
 	struct task_struct *gc_ts;
 	struct task_struct *gc_writer_ts;
+	struct task_struct *gc_reader_ts;
+
+	struct workqueue_struct *gc_line_reader_wq;
 	struct workqueue_struct *gc_reader_wq;
+
 	struct timer_list gc_timer;
 
+	struct semaphore gc_sem;
+	atomic_t inflight_gc;
 	int w_entries;
+
 	struct list_head w_list;
+	struct list_head r_list;
 
 	spinlock_t lock;
 	spinlock_t w_lock;
+	spinlock_t r_lock;
 };
 
 struct pblk_rl {
@@ -229,10 +238,8 @@ struct pblk_rl {
 				 */
 	unsigned int high_pw;	/* High rounded up as a power of 2 */
 
-#define PBLK_USER_HIGH_THRS 2	/* Begin write limit at 50 percent
-				 * available blks
-				 */
-#define PBLK_USER_LOW_THRS 20	/* Aggressive GC at 5% available blocks */
+#define PBLK_USER_HIGH_THRS 8	/* Begin write limit at 12% available blks */
+#define PBLK_USER_LOW_THRS 10	/* Aggressive GC at 10% available blocks */
 
 	int rb_windows_pw;	/* Number of rate windows in the write buffer
 				 * given as a power-of-2. This guarantees that
@@ -250,7 +257,11 @@ struct pblk_rl {
 	int rb_state;		/* Rate-limiter current state */
 	atomic_t rb_gc_cnt;	/* GC I/O buffer counter */
 
+	int rsv_blocks;		/* Reserved blocks for GC */
+
 	int rb_user_active;
+	int rb_gc_active;
+
 	struct timer_list u_timer;
 
 	unsigned long long nr_secs;
@@ -428,7 +439,7 @@ struct pblk_line_mgmt {
 	struct list_head bad_list;	/* Full lines bad */
 
 	/* GC lists - use gc_lock */
-	struct list_head *gc_lists[PBLK_NR_GC_LISTS];
+	struct list_head *gc_lists[PBLK_GC_NR_LISTS];
 	struct list_head gc_high_list;	/* Full lines ready to GC, high isc */
 	struct list_head gc_mid_list;	/* Full lines ready to GC, mid isc */
 	struct list_head gc_low_list;	/* Full lines ready to GC, low isc */
@@ -767,30 +778,34 @@ int pblk_recov_setup_rq(struct pblk *pblk, struct pblk_c_ctx *c_ctx,
 /*
  * pblk gc
  */
-#define PBLK_GC_TRIES 3
+#define PBLK_GC_MAX_READERS 8	/* Max number of outstanding GC reader jobs */
+#define PBLK_GC_W_QD 1024	/* Queue depth for inflight GC write I/Os */
+#define PBLK_GC_L_QD 4		/* Queue depth for inflight GC lines */
+#define PBLK_GC_RSV_LINE 1	/* Reserved lines for GC */
 
 int pblk_gc_init(struct pblk *pblk);
 void pblk_gc_exit(struct pblk *pblk);
 void pblk_gc_should_start(struct pblk *pblk);
 void pblk_gc_should_stop(struct pblk *pblk);
-int pblk_gc_status(struct pblk *pblk);
+void pblk_gc_should_kick(struct pblk *pblk);
+void pblk_gc_kick(struct pblk *pblk);
 void pblk_gc_sysfs_state_show(struct pblk *pblk, int *gc_enabled,
 			      int *gc_active);
-void pblk_gc_sysfs_force(struct pblk *pblk, int force);
+int pblk_gc_sysfs_force(struct pblk *pblk, int force);
 
 /*
  * pblk rate limiter
  */
 void pblk_rl_init(struct pblk_rl *rl, int budget);
 void pblk_rl_free(struct pblk_rl *rl);
-int pblk_rl_gc_thrs(struct pblk_rl *rl);
+int pblk_rl_high_thrs(struct pblk_rl *rl);
+int pblk_rl_low_thrs(struct pblk_rl *rl);
 unsigned long pblk_rl_nr_free_blks(struct pblk_rl *rl);
 int pblk_rl_user_may_insert(struct pblk_rl *rl, int nr_entries);
 void pblk_rl_user_in(struct pblk_rl *rl, int nr_entries);
 int pblk_rl_gc_may_insert(struct pblk_rl *rl, int nr_entries);
 void pblk_rl_gc_in(struct pblk_rl *rl, int nr_entries);
 void pblk_rl_out(struct pblk_rl *rl, int nr_user, int nr_gc);
-void pblk_rl_set_gc_rsc(struct pblk_rl *rl, int rsv);
 int pblk_rl_sysfs_rate_show(struct pblk_rl *rl);
 void pblk_rl_free_lines_inc(struct pblk_rl *rl, struct pblk_line *line);
 void pblk_rl_free_lines_dec(struct pblk_rl *rl, struct pblk_line *line);
@@ -836,6 +851,17 @@ static inline void *emeta_to_vsc(struct pblk *pblk, struct line_emeta *emeta)
 	return (emeta_to_lbas(pblk, emeta) + pblk->lm.emeta_len[2]);
 }
 
+static inline int pblk_line_vsc(struct pblk_line *line)
+{
+	int vsc;
+
+	spin_lock(&line->lock);
+	vsc = le32_to_cpu(*line->vsc);
+	spin_unlock(&line->lock);
+
+	return vsc;
+}
+
 #define NVM_MEM_PAGE_WRITE (8)
 
 static inline int pblk_pad_distance(struct pblk *pblk)
-- 
2.7.4

[PATCH 19/20] lightnvm: pblk: set mempool and workqueue params.

[Javier González]

Make constants to define sizes for internal mempools and workqueues. In
this process, adjust the values to be more meaningful given the internal
constrains of the FTL. In order to do this for workqueues, separate the
current auxiliary workqueue into two dedicated workqueues to manage
lines being closed and bad blocks.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/pblk-core.c  |  7 ++++---
 drivers/lightnvm/pblk-init.c  | 39 ++++++++++++++++++++++++++-------------
 drivers/lightnvm/pblk-write.c |  5 +++--
 drivers/lightnvm/pblk.h       | 13 +++++++++++--
 4 files changed, 44 insertions(+), 20 deletions(-)

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index ba3b88f0e1f7..823e53f95a80 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -33,7 +33,7 @@ static void pblk_mark_bb(struct pblk *pblk, struct pblk_line *line,
 		pr_err("pblk: attempted to erase bb: line:%d, pos:%d\n",
 							line->id, pos);
 
-	pblk_line_run_ws(pblk, NULL, ppa, pblk_line_mark_bb);
+	pblk_line_run_ws(pblk, NULL, ppa, pblk_line_mark_bb, pblk->bb_wq);
 }
 
 static void __pblk_end_io_erase(struct pblk *pblk, struct nvm_rq *rqd)
@@ -1528,7 +1528,8 @@ void pblk_line_mark_bb(struct work_struct *work)
 }
 
 void pblk_line_run_ws(struct pblk *pblk, struct pblk_line *line, void *priv,
-		      void (*work)(struct work_struct *))
+		      void (*work)(struct work_struct *),
+		      struct workqueue_struct *wq)
 {
 	struct pblk_line_ws *line_ws;
 
@@ -1541,7 +1542,7 @@ void pblk_line_run_ws(struct pblk *pblk, struct pblk_line *line, void *priv,
 	line_ws->priv = priv;
 
 	INIT_WORK(&line_ws->ws, work);
-	queue_work(pblk->kw_wq, &line_ws->ws);
+	queue_work(wq, &line_ws->ws);
 }
 
 void pblk_down_rq(struct pblk *pblk, struct ppa_addr *ppa_list, int nr_ppas,
diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
index 41db12deaa49..78a9bebac1fe 100644
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -250,7 +250,7 @@ static int pblk_core_init(struct pblk *pblk)
 	if (!pblk->page_pool)
 		return -ENOMEM;
 
-	pblk->line_ws_pool = mempool_create_slab_pool(geo->nr_luns,
+	pblk->line_ws_pool = mempool_create_slab_pool(PBLK_WS_POOL_SIZE,
 							pblk_blk_ws_cache);
 	if (!pblk->line_ws_pool)
 		goto free_page_pool;
@@ -259,35 +259,45 @@ static int pblk_core_init(struct pblk *pblk)
 	if (!pblk->rec_pool)
 		goto free_blk_ws_pool;
 
-	pblk->g_rq_pool = mempool_create_slab_pool(64, pblk_g_rq_cache);
+	pblk->g_rq_pool = mempool_create_slab_pool(PBLK_READ_REQ_POOL_SIZE,
+							pblk_g_rq_cache);
 	if (!pblk->g_rq_pool)
 		goto free_rec_pool;
 
-	pblk->w_rq_pool = mempool_create_slab_pool(64, pblk_w_rq_cache);
+	pblk->w_rq_pool = mempool_create_slab_pool(geo->nr_luns * 2,
+							pblk_w_rq_cache);
 	if (!pblk->w_rq_pool)
 		goto free_g_rq_pool;
 
 	pblk->line_meta_pool =
-			mempool_create_slab_pool(16, pblk_line_meta_cache);
+			mempool_create_slab_pool(PBLK_META_POOL_SIZE,
+							pblk_line_meta_cache);
 	if (!pblk->line_meta_pool)
 		goto free_w_rq_pool;
 
-	pblk->kw_wq = alloc_workqueue("pblk-aux-wq",
-					WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
-	if (!pblk->kw_wq)
+	pblk->close_wq = alloc_workqueue("pblk-close-wq",
+			WQ_MEM_RECLAIM | WQ_UNBOUND, PBLK_NR_CLOSE_JOBS);
+	if (!pblk->close_wq)
 		goto free_line_meta_pool;
 
+	pblk->bb_wq = alloc_workqueue("pblk-bb-wq",
+			WQ_MEM_RECLAIM | WQ_UNBOUND, 0);
+	if (!pblk->bb_wq)
+		goto free_close_wq;
+
 	if (pblk_set_ppaf(pblk))
-		goto free_kw_wq;
+		goto free_bb_wq;
 
 	if (pblk_rwb_init(pblk))
-		goto free_kw_wq;
+		goto free_bb_wq;
 
 	INIT_LIST_HEAD(&pblk->compl_list);
 	return 0;
 
-free_kw_wq:
-	destroy_workqueue(pblk->kw_wq);
+free_bb_wq:
+	destroy_workqueue(pblk->bb_wq);
+free_close_wq:
+	destroy_workqueue(pblk->close_wq);
 free_line_meta_pool:
 	mempool_destroy(pblk->line_meta_pool);
 free_w_rq_pool:
@@ -305,8 +315,11 @@ static int pblk_core_init(struct pblk *pblk)
 
 static void pblk_core_free(struct pblk *pblk)
 {
-	if (pblk->kw_wq)
-		destroy_workqueue(pblk->kw_wq);
+	if (pblk->close_wq)
+		destroy_workqueue(pblk->close_wq);
+
+	if (pblk->bb_wq)
+		destroy_workqueue(pblk->bb_wq);
 
 	mempool_destroy(pblk->page_pool);
 	mempool_destroy(pblk->line_ws_pool);
diff --git a/drivers/lightnvm/pblk-write.c b/drivers/lightnvm/pblk-write.c
index a50bfbd12c32..f071fb79e199 100644
--- a/drivers/lightnvm/pblk-write.c
+++ b/drivers/lightnvm/pblk-write.c
@@ -150,7 +150,7 @@ static void pblk_end_w_fail(struct pblk *pblk, struct nvm_rq *rqd)
 	}
 
 	INIT_WORK(&recovery->ws_rec, pblk_submit_rec);
-	queue_work(pblk->kw_wq, &recovery->ws_rec);
+	queue_work(pblk->close_wq, &recovery->ws_rec);
 
 out:
 	pblk_complete_write(pblk, rqd, c_ctx);
@@ -198,7 +198,8 @@ static void pblk_end_io_write_meta(struct nvm_rq *rqd)
 
 	sync = atomic_add_return(rqd->nr_ppas, &emeta->sync);
 	if (sync == emeta->nr_entries)
-		pblk_line_run_ws(pblk, line, NULL, pblk_line_close_ws);
+		pblk_line_run_ws(pblk, line, NULL, pblk_line_close_ws,
+								pblk->close_wq);
 
 	bio_put(rqd->bio);
 	pblk_free_rqd(pblk, rqd, READ);
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index aaee718f1029..862bca130144 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -40,6 +40,12 @@
 #define PBLK_MAX_REQ_ADDRS (64)
 #define PBLK_MAX_REQ_ADDRS_PW (6)
 
+#define PBLK_WS_POOL_SIZE (128)
+#define PBLK_META_POOL_SIZE (128)
+#define PBLK_READ_REQ_POOL_SIZE (1024)
+
+#define PBLK_NR_CLOSE_JOBS (4)
+
 #define PBLK_CACHE_NAME_LEN (DISK_NAME_LEN + 16)
 
 #define PBLK_COMMAND_TIMEOUT_MS 30000
@@ -599,7 +605,9 @@ struct pblk {
 	mempool_t *w_rq_pool;
 	mempool_t *line_meta_pool;
 
-	struct workqueue_struct *kw_wq;
+	struct workqueue_struct *close_wq;
+	struct workqueue_struct *bb_wq;
+
 	struct timer_list wtimer;
 
 	struct pblk_gc gc;
@@ -692,7 +700,8 @@ void pblk_line_close(struct pblk *pblk, struct pblk_line *line);
 void pblk_line_close_ws(struct work_struct *work);
 void pblk_line_mark_bb(struct work_struct *work);
 void pblk_line_run_ws(struct pblk *pblk, struct pblk_line *line, void *priv,
-		      void (*work)(struct work_struct *));
+		      void (*work)(struct work_struct *),
+		      struct workqueue_struct *wq);
 u64 pblk_line_smeta_start(struct pblk *pblk, struct pblk_line *line);
 int pblk_line_read_smeta(struct pblk *pblk, struct pblk_line *line);
 int pblk_line_read_emeta(struct pblk *pblk, struct pblk_line *line,
-- 
2.7.4

[PATCH 20/20] lightnvm: pblk: fail gracefully on irrec. error

[Javier González]

Due to user writes being decoupled from media writes because of the need
of an intermediate write buffer, irrecoverable media write errors lead
to pblk stalling; user writes fill up the buffer and end up in an
infinite retry loop.

In order to let user writes fail gracefully, it is necessary for pblk to
keep track of its own internal state and prevent further writes from
being placed into the write buffer.

This patch implements a state machine to keep track of internal errors
and, in case of failure, fail further user writes in an standard way.
Depending on the type of error, pblk will do its best to persist
buffered writes (which are already acknowledged) and close down on a
graceful manner. This way, data might be recovered by re-instantiating
pblk. Such state machine paves out the way for a state-based FTL log.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/pblk-cache.c    |   8 +-
 drivers/lightnvm/pblk-core.c     | 280 ++++++++++++++++++++++++++++-----------
 drivers/lightnvm/pblk-init.c     |   6 +-
 drivers/lightnvm/pblk-map.c      |  23 +++-
 drivers/lightnvm/pblk-rb.c       |  25 +++-
 drivers/lightnvm/pblk-read.c     |   3 +
 drivers/lightnvm/pblk-recovery.c |  31 +++--
 drivers/lightnvm/pblk-rl.c       |  30 ++++-
 drivers/lightnvm/pblk-sysfs.c    |   8 +-
 drivers/lightnvm/pblk-write.c    |   5 +-
 drivers/lightnvm/pblk.h          |  27 +++-
 11 files changed, 332 insertions(+), 114 deletions(-)

diff --git a/drivers/lightnvm/pblk-cache.c b/drivers/lightnvm/pblk-cache.c
index 59bcea88db84..024a8fc93069 100644
--- a/drivers/lightnvm/pblk-cache.c
+++ b/drivers/lightnvm/pblk-cache.c
@@ -31,9 +31,13 @@ int pblk_write_to_cache(struct pblk *pblk, struct bio *bio, unsigned long flags)
 	 */
 retry:
 	ret = pblk_rb_may_write_user(&pblk->rwb, bio, nr_entries, &bpos);
-	if (ret == NVM_IO_REQUEUE) {
+	switch (ret) {
+	case NVM_IO_REQUEUE:
 		io_schedule();
 		goto retry;
+	case NVM_IO_ERR:
+		pblk_pipeline_stop(pblk);
+		goto out;
 	}
 
 	if (unlikely(!bio_has_data(bio)))
@@ -58,6 +62,8 @@ int pblk_write_to_cache(struct pblk *pblk, struct bio *bio, unsigned long flags)
 	atomic_long_add(nr_entries, &pblk->req_writes);
 #endif
 
+	pblk_rl_inserted(&pblk->rl, nr_entries);
+
 out:
 	pblk_write_should_kick(pblk);
 	return ret;
diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index 823e53f95a80..7648186bd1b1 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -53,6 +53,8 @@ static void __pblk_end_io_erase(struct pblk *pblk, struct nvm_rq *rqd)
 		*ppa = rqd->ppa_addr;
 		pblk_mark_bb(pblk, line, ppa);
 	}
+
+	atomic_dec(&pblk->inflight_io);
 }
 
 /* Erase completion assumes that only one block is erased at the time */
@@ -257,35 +259,25 @@ void pblk_end_io_sync(struct nvm_rq *rqd)
 	complete(waiting);
 }
 
-void pblk_flush_writer(struct pblk *pblk)
+void pblk_wait_for_meta(struct pblk *pblk)
 {
-	struct bio *bio;
-	int ret;
-	DECLARE_COMPLETION_ONSTACK(wait);
+	do {
+		if (!atomic_read(&pblk->inflight_io))
+			break;
 
-	bio = bio_alloc(GFP_KERNEL, 1);
-	if (!bio)
-		return;
+		schedule();
+	} while (1);
+}
 
-	bio->bi_iter.bi_sector = 0; /* internal bio */
-	bio_set_op_attrs(bio, REQ_OP_WRITE, REQ_OP_FLUSH);
-	bio->bi_private = &wait;
-	bio->bi_end_io = pblk_end_bio_sync;
-
-	ret = pblk_write_to_cache(pblk, bio, 0);
-	if (ret == NVM_IO_OK) {
-		if (!wait_for_completion_io_timeout(&wait,
-				msecs_to_jiffies(PBLK_COMMAND_TIMEOUT_MS))) {
-			pr_err("pblk: flush cache timed out\n");
-		}
-	} else if (ret != NVM_IO_DONE) {
-		pr_err("pblk: tear down bio failed\n");
-	}
-
-	if (bio->bi_status)
-		pr_err("pblk: flush sync write failed (%u)\n", bio->bi_status);
+static void pblk_flush_writer(struct pblk *pblk)
+{
+	pblk_rb_flush(&pblk->rwb);
+	do {
+		if (!pblk_rb_read_count(&pblk->rwb))
+			break;
 
-	bio_put(bio);
+		schedule();
+	} while (1);
 }
 
 struct list_head *pblk_line_gc_list(struct pblk *pblk, struct pblk_line *line)
@@ -425,6 +417,9 @@ int pblk_submit_io(struct pblk *pblk, struct nvm_rq *rqd)
 		}
 	}
 #endif
+
+	atomic_inc(&pblk->inflight_io);
+
 	return nvm_submit_io(dev, rqd);
 }
 
@@ -676,6 +671,7 @@ static int pblk_line_submit_emeta_io(struct pblk *pblk, struct pblk_line *line,
 				msecs_to_jiffies(PBLK_COMMAND_TIMEOUT_MS))) {
 		pr_err("pblk: emeta I/O timed out\n");
 	}
+	atomic_dec(&pblk->inflight_io);
 	reinit_completion(&wait);
 
 	if (likely(pblk->l_mg.emeta_alloc_type == PBLK_VMALLOC_META))
@@ -791,6 +787,7 @@ static int pblk_line_submit_smeta_io(struct pblk *pblk, struct pblk_line *line,
 				msecs_to_jiffies(PBLK_COMMAND_TIMEOUT_MS))) {
 		pr_err("pblk: smeta I/O timed out\n");
 	}
+	atomic_dec(&pblk->inflight_io);
 
 	if (rqd.error) {
 		if (dir == WRITE)
@@ -832,7 +829,7 @@ static void pblk_setup_e_rq(struct pblk *pblk, struct nvm_rq *rqd,
 static int pblk_blk_erase_sync(struct pblk *pblk, struct ppa_addr ppa)
 {
 	struct nvm_rq rqd;
-	int ret;
+	int ret = 0;
 	DECLARE_COMPLETION_ONSTACK(wait);
 
 	memset(&rqd, 0, sizeof(struct nvm_rq));
@@ -867,14 +864,14 @@ static int pblk_blk_erase_sync(struct pblk *pblk, struct ppa_addr ppa)
 	rqd.private = pblk;
 	__pblk_end_io_erase(pblk, &rqd);
 
-	return 0;
+	return ret;
 }
 
 int pblk_line_erase(struct pblk *pblk, struct pblk_line *line)
 {
 	struct pblk_line_meta *lm = &pblk->lm;
 	struct ppa_addr ppa;
-	int bit = -1;
+	int ret, bit = -1;
 
 	/* Erase only good blocks, one at a time */
 	do {
@@ -893,9 +890,10 @@ int pblk_line_erase(struct pblk *pblk, struct pblk_line *line)
 		WARN_ON(test_and_set_bit(bit, line->erase_bitmap));
 		spin_unlock(&line->lock);
 
-		if (pblk_blk_erase_sync(pblk, ppa)) {
+		ret = pblk_blk_erase_sync(pblk, ppa);
+		if (ret) {
 			pr_err("pblk: failed to erase line %d\n", line->id);
-			return -ENOMEM;
+			return ret;
 		}
 	} while (1);
 
@@ -908,6 +906,8 @@ static void pblk_line_setup_metadata(struct pblk_line *line,
 {
 	int meta_line;
 
+	lockdep_assert_held(&l_mg->free_lock);
+
 retry_meta:
 	meta_line = find_first_zero_bit(&l_mg->meta_bitmap, PBLK_DATA_LINES);
 	if (meta_line == PBLK_DATA_LINES) {
@@ -1039,7 +1039,6 @@ static int pblk_line_init_bb(struct pblk *pblk, struct pblk_line *line,
 	/* Mark smeta metadata sectors as bad sectors */
 	bit = find_first_zero_bit(line->blk_bitmap, lm->blk_per_line);
 	off = bit * geo->sec_per_pl;
-retry_smeta:
 	bitmap_set(line->map_bitmap, off, lm->smeta_sec);
 	line->sec_in_line -= lm->smeta_sec;
 	line->smeta_ssec = off;
@@ -1047,8 +1046,7 @@ static int pblk_line_init_bb(struct pblk *pblk, struct pblk_line *line,
 
 	if (init && pblk_line_submit_smeta_io(pblk, line, off, WRITE)) {
 		pr_debug("pblk: line smeta I/O failed. Retry\n");
-		off += geo->sec_per_pl;
-		goto retry_smeta;
+		return 1;
 	}
 
 	bitmap_copy(line->invalid_bitmap, line->map_bitmap, lm->sec_per_line);
@@ -1110,10 +1108,14 @@ static int pblk_line_prepare(struct pblk *pblk, struct pblk_line *line)
 
 	spin_lock(&line->lock);
 	if (line->state != PBLK_LINESTATE_FREE) {
+		mempool_free(line->invalid_bitmap, pblk->line_meta_pool);
+		mempool_free(line->map_bitmap, pblk->line_meta_pool);
 		spin_unlock(&line->lock);
-		WARN(1, "pblk: corrupted line state\n");
-		return -EINTR;
+		WARN(1, "pblk: corrupted line %d, state %d\n",
+							line->id, line->state);
+		return -EAGAIN;
 	}
+
 	line->state = PBLK_LINESTATE_OPEN;
 
 	atomic_set(&line->left_eblks, blk_in_line);
@@ -1169,15 +1171,15 @@ struct pblk_line *pblk_line_get(struct pblk *pblk)
 {
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 	struct pblk_line_meta *lm = &pblk->lm;
-	struct pblk_line *line = NULL;
-	int bit;
+	struct pblk_line *line;
+	int ret, bit;
 
 	lockdep_assert_held(&l_mg->free_lock);
 
-retry_get:
+retry:
 	if (list_empty(&l_mg->free_list)) {
 		pr_err("pblk: no free lines\n");
-		goto out;
+		return NULL;
 	}
 
 	line = list_first_entry(&l_mg->free_list, struct pblk_line, list);
@@ -1193,17 +1195,22 @@ struct pblk_line *pblk_line_get(struct pblk *pblk)
 		list_add_tail(&line->list, &l_mg->bad_list);
 
 		pr_debug("pblk: line %d is bad\n", line->id);
-		goto retry_get;
+		goto retry;
 	}
 
-	if (pblk_line_prepare(pblk, line)) {
-		pr_err("pblk: failed to prepare line %d\n", line->id);
-		list_add(&line->list, &l_mg->free_list);
-		l_mg->nr_free_lines++;
-		return NULL;
+	ret = pblk_line_prepare(pblk, line);
+	if (ret) {
+		if (ret == -EAGAIN) {
+			list_add(&line->list, &l_mg->corrupt_list);
+			goto retry;
+		} else {
+			pr_err("pblk: failed to prepare line %d\n", line->id);
+			list_add(&line->list, &l_mg->free_list);
+			l_mg->nr_free_lines++;
+			return NULL;
+		}
 	}
 
-out:
 	return line;
 }
 
@@ -1213,6 +1220,7 @@ static struct pblk_line *pblk_line_retry(struct pblk *pblk,
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 	struct pblk_line *retry_line;
 
+retry:
 	spin_lock(&l_mg->free_lock);
 	retry_line = pblk_line_get(pblk);
 	if (!retry_line) {
@@ -1229,18 +1237,21 @@ static struct pblk_line *pblk_line_retry(struct pblk *pblk,
 	l_mg->data_line = retry_line;
 	spin_unlock(&l_mg->free_lock);
 
-	if (pblk_line_erase(pblk, retry_line)) {
-		spin_lock(&l_mg->free_lock);
-		l_mg->data_line = NULL;
-		spin_unlock(&l_mg->free_lock);
-		return NULL;
-	}
-
 	pblk_rl_free_lines_dec(&pblk->rl, retry_line);
 
+	if (pblk_line_erase(pblk, retry_line))
+		goto retry;
+
 	return retry_line;
 }
 
+static void pblk_set_space_limit(struct pblk *pblk)
+{
+	struct pblk_rl *rl = &pblk->rl;
+
+	atomic_set(&rl->rb_space, 0);
+}
+
 struct pblk_line *pblk_line_get_first_data(struct pblk *pblk)
 {
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
@@ -1262,20 +1273,31 @@ struct pblk_line *pblk_line_get_first_data(struct pblk *pblk)
 
 	/* Allocate next line for preparation */
 	l_mg->data_next = pblk_line_get(pblk);
-	if (l_mg->data_next) {
+	if (!l_mg->data_next) {
+		/* If we cannot get a new line, we need to stop the pipeline.
+		 * Only allow as many writes in as we can store safely and then
+		 * fail gracefully
+		 */
+		pblk_set_space_limit(pblk);
+
+		l_mg->data_next = NULL;
+	} else {
 		l_mg->data_next->seq_nr = l_mg->d_seq_nr++;
 		l_mg->data_next->type = PBLK_LINETYPE_DATA;
 		is_next = 1;
 	}
 	spin_unlock(&l_mg->free_lock);
 
+	if (pblk_line_erase(pblk, line)) {
+		line = pblk_line_retry(pblk, line);
+		if (!line)
+			return NULL;
+	}
+
 	pblk_rl_free_lines_dec(&pblk->rl, line);
 	if (is_next)
 		pblk_rl_free_lines_dec(&pblk->rl, l_mg->data_next);
 
-	if (pblk_line_erase(pblk, line))
-		return NULL;
-
 retry_setup:
 	if (!pblk_line_init_metadata(pblk, line, NULL)) {
 		line = pblk_line_retry(pblk, line);
@@ -1296,7 +1318,47 @@ struct pblk_line *pblk_line_get_first_data(struct pblk *pblk)
 	return line;
 }
 
-struct pblk_line *pblk_line_replace_data(struct pblk *pblk)
+static void pblk_stop_writes(struct pblk *pblk, struct pblk_line *line)
+{
+	lockdep_assert_held(&pblk->l_mg.free_lock);
+
+	pblk_set_space_limit(pblk);
+	pblk->state = PBLK_STATE_STOPPING;
+}
+
+void pblk_pipeline_stop(struct pblk *pblk)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	int ret;
+
+	spin_lock(&l_mg->free_lock);
+	if (pblk->state == PBLK_STATE_RECOVERING ||
+					pblk->state == PBLK_STATE_STOPPED) {
+		spin_unlock(&l_mg->free_lock);
+		return;
+	}
+	pblk->state = PBLK_STATE_RECOVERING;
+	spin_unlock(&l_mg->free_lock);
+
+	pblk_flush_writer(pblk);
+	pblk_wait_for_meta(pblk);
+
+	ret = pblk_recov_pad(pblk);
+	if (ret) {
+		pr_err("pblk: could not close data on teardown(%d)\n", ret);
+		return;
+	}
+
+	pblk_line_close_meta_sync(pblk);
+
+	spin_lock(&l_mg->free_lock);
+	pblk->state = PBLK_STATE_STOPPED;
+	l_mg->data_line = NULL;
+	l_mg->data_next = NULL;
+	spin_unlock(&l_mg->free_lock);
+}
+
+void pblk_line_replace_data(struct pblk *pblk)
 {
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 	struct pblk_line *cur, *new;
@@ -1306,42 +1368,38 @@ struct pblk_line *pblk_line_replace_data(struct pblk *pblk)
 	cur = l_mg->data_line;
 	new = l_mg->data_next;
 	if (!new)
-		return NULL;
+		return;
 	l_mg->data_line = new;
 
-retry_line:
+	spin_lock(&l_mg->free_lock);
+	if (pblk->state != PBLK_STATE_RUNNING) {
+		l_mg->data_line = NULL;
+		l_mg->data_next = NULL;
+		spin_unlock(&l_mg->free_lock);
+		return;
+	}
+
+	pblk_line_setup_metadata(new, l_mg, &pblk->lm);
+	spin_unlock(&l_mg->free_lock);
+
+retry_erase:
 	left_seblks = atomic_read(&new->left_seblks);
 	if (left_seblks) {
 		/* If line is not fully erased, erase it */
 		if (atomic_read(&new->left_eblks)) {
 			if (pblk_line_erase(pblk, new))
-				return NULL;
+				return;
 		} else {
 			io_schedule();
 		}
-		goto retry_line;
+		goto retry_erase;
 	}
 
-	spin_lock(&l_mg->free_lock);
-	/* Allocate next line for preparation */
-	l_mg->data_next = pblk_line_get(pblk);
-	if (l_mg->data_next) {
-		l_mg->data_next->seq_nr = l_mg->d_seq_nr++;
-		l_mg->data_next->type = PBLK_LINETYPE_DATA;
-		is_next = 1;
-	}
-
-	pblk_line_setup_metadata(new, l_mg, &pblk->lm);
-	spin_unlock(&l_mg->free_lock);
-
-	if (is_next)
-		pblk_rl_free_lines_dec(&pblk->rl, l_mg->data_next);
-
 retry_setup:
 	if (!pblk_line_init_metadata(pblk, new, cur)) {
 		new = pblk_line_retry(pblk, new);
 		if (!new)
-			return NULL;
+			return;
 
 		goto retry_setup;
 	}
@@ -1349,12 +1407,30 @@ struct pblk_line *pblk_line_replace_data(struct pblk *pblk)
 	if (!pblk_line_init_bb(pblk, new, 1)) {
 		new = pblk_line_retry(pblk, new);
 		if (!new)
-			return NULL;
+			return;
 
 		goto retry_setup;
 	}
 
-	return new;
+	/* Allocate next line for preparation */
+	spin_lock(&l_mg->free_lock);
+	l_mg->data_next = pblk_line_get(pblk);
+	if (!l_mg->data_next) {
+		/* If we cannot get a new line, we need to stop the pipeline.
+		 * Only allow as many writes in as we can store safely and then
+		 * fail gracefully
+		 */
+		pblk_stop_writes(pblk, new);
+		l_mg->data_next = NULL;
+	} else {
+		l_mg->data_next->seq_nr = l_mg->d_seq_nr++;
+		l_mg->data_next->type = PBLK_LINETYPE_DATA;
+		is_next = 1;
+	}
+	spin_unlock(&l_mg->free_lock);
+
+	if (is_next)
+		pblk_rl_free_lines_dec(&pblk->rl, l_mg->data_next);
 }
 
 void pblk_line_free(struct pblk *pblk, struct pblk_line *line)
@@ -1438,6 +1514,46 @@ int pblk_line_is_full(struct pblk_line *line)
 	return (line->left_msecs == 0);
 }
 
+void pblk_line_close_meta_sync(struct pblk *pblk)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_line *line, *tline;
+	LIST_HEAD(list);
+
+	spin_lock(&l_mg->close_lock);
+	if (list_empty(&l_mg->emeta_list)) {
+		spin_unlock(&l_mg->close_lock);
+		return;
+	}
+
+	list_cut_position(&list, &l_mg->emeta_list, l_mg->emeta_list.prev);
+	spin_unlock(&l_mg->close_lock);
+
+	list_for_each_entry_safe(line, tline, &list, list) {
+		struct pblk_emeta *emeta = line->emeta;
+
+		while (emeta->mem < lm->emeta_len[0]) {
+			int ret;
+
+			ret = pblk_submit_meta_io(pblk, line);
+			if (ret) {
+				pr_err("pblk: sync meta line %d failed (%d)\n",
+							line->id, ret);
+				return;
+			}
+		}
+	}
+
+	pblk_wait_for_meta(pblk);
+}
+
+static void pblk_line_should_sync_meta(struct pblk *pblk)
+{
+	if (pblk_rl_is_limit(&pblk->rl))
+		pblk_line_close_meta_sync(pblk);
+}
+
 void pblk_line_close(struct pblk *pblk, struct pblk_line *line)
 {
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
@@ -1477,7 +1593,7 @@ void pblk_line_close_meta(struct pblk *pblk, struct pblk_line *line)
 	struct pblk_emeta *emeta = line->emeta;
 	struct line_emeta *emeta_buf = emeta->buf;
 
-	/* No need for exact vsc value; avoid a big line lock and tak aprox. */
+	/* No need for exact vsc value; avoid a big line lock and take aprox. */
 	memcpy(emeta_to_vsc(pblk, emeta_buf), l_mg->vsc_list, lm->vsc_list_len);
 	memcpy(emeta_to_bb(emeta_buf), line->blk_bitmap, lm->blk_bitmap_len);
 
@@ -1489,6 +1605,8 @@ void pblk_line_close_meta(struct pblk *pblk, struct pblk_line *line)
 	list_add_tail(&line->list, &l_mg->emeta_list);
 	spin_unlock(&line->lock);
 	spin_unlock(&l_mg->close_lock);
+
+	pblk_line_should_sync_meta(pblk);
 }
 
 void pblk_line_close_ws(struct work_struct *work)
diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
index 78a9bebac1fe..5423518f234a 100644
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -371,11 +371,13 @@ static void pblk_line_meta_free(struct pblk *pblk)
 	kfree(l_mg->bb_aux);
 	kfree(l_mg->vsc_list);
 
+	spin_lock(&l_mg->free_lock);
 	for (i = 0; i < PBLK_DATA_LINES; i++) {
 		kfree(l_mg->sline_meta[i]);
 		pblk_mfree(l_mg->eline_meta[i]->buf, l_mg->emeta_alloc_type);
 		kfree(l_mg->eline_meta[i]);
 	}
+	spin_unlock(&l_mg->free_lock);
 
 	kfree(pblk->lines);
 }
@@ -858,10 +860,9 @@ static void pblk_free(struct pblk *pblk)
 
 static void pblk_tear_down(struct pblk *pblk)
 {
-	pblk_flush_writer(pblk);
+	pblk_pipeline_stop(pblk);
 	pblk_writer_stop(pblk);
 	pblk_rb_sync_l2p(&pblk->rwb);
-	pblk_recov_pad(pblk);
 	pblk_rwb_free(pblk);
 	pblk_rl_free(&pblk->rl);
 
@@ -907,6 +908,7 @@ static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
 
 	pblk->dev = dev;
 	pblk->disk = tdisk;
+	pblk->state = PBLK_STATE_RUNNING;
 
 	spin_lock_init(&pblk->trans_lock);
 	spin_lock_init(&pblk->lock);
diff --git a/drivers/lightnvm/pblk-map.c b/drivers/lightnvm/pblk-map.c
index 9942d9bc7b3a..a9be03cd07a8 100644
--- a/drivers/lightnvm/pblk-map.c
+++ b/drivers/lightnvm/pblk-map.c
@@ -62,9 +62,8 @@ static void pblk_map_page_data(struct pblk *pblk, unsigned int sentry,
 
 	if (pblk_line_is_full(line)) {
 		struct pblk_line *prev_line = line;
-		line = pblk_line_replace_data(pblk);
-		if (!line)
-			return;
+
+		pblk_line_replace_data(pblk);
 		pblk_line_close_meta(pblk, prev_line);
 	}
 
@@ -106,10 +105,16 @@ void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
 		pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
 					lun_bitmap, &meta_list[i], map_secs);
 
-		/* line can change after page map */
-		e_line = pblk_line_get_erase(pblk);
 		erase_lun = pblk_ppa_to_pos(geo, rqd->ppa_list[i]);
 
+		/* line can change after page map. We might also be writing the
+		 * last line.
+		 */
+		e_line = pblk_line_get_erase(pblk);
+		if (!e_line)
+			return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
+							valid_secs, i + min);
+
 		spin_lock(&e_line->lock);
 		if (!test_bit(erase_lun, e_line->erase_bitmap)) {
 			set_bit(erase_lun, e_line->erase_bitmap);
@@ -127,9 +132,15 @@ void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
 		spin_unlock(&e_line->lock);
 	}
 
-	e_line = pblk_line_get_erase(pblk);
 	d_line = pblk_line_get_data(pblk);
 
+	/* line can change after page map. We might also be writing the
+	 * last line.
+	 */
+	e_line = pblk_line_get_erase(pblk);
+	if (!e_line)
+		return;
+
 	/* Erase blocks that are bad in this line but might not be in next */
 	if (unlikely(ppa_empty(*erase_ppa)) &&
 			bitmap_weight(d_line->blk_bitmap, lm->blk_per_line)) {
diff --git a/drivers/lightnvm/pblk-rb.c b/drivers/lightnvm/pblk-rb.c
index 50886878568b..665a4ccfe7f5 100644
--- a/drivers/lightnvm/pblk-rb.c
+++ b/drivers/lightnvm/pblk-rb.c
@@ -369,6 +369,9 @@ static int pblk_rb_sync_point_set(struct pblk_rb *rb, struct bio *bio,
 	/* Protect syncs */
 	smp_store_release(&rb->sync_point, sync_point);
 
+	if (!bio)
+		return 0;
+
 	spin_lock_irq(&rb->s_lock);
 	bio_list_add(&entry->w_ctx.bios, bio);
 	spin_unlock_irq(&rb->s_lock);
@@ -407,6 +410,17 @@ static int pblk_rb_may_write(struct pblk_rb *rb, unsigned int nr_entries,
 	return 1;
 }
 
+void pblk_rb_flush(struct pblk_rb *rb)
+{
+	struct pblk *pblk = container_of(rb, struct pblk, rwb);
+	unsigned int mem = READ_ONCE(rb->mem);
+
+	if (pblk_rb_sync_point_set(rb, NULL, mem))
+		return;
+
+	pblk_write_should_kick(pblk);
+}
+
 static int pblk_rb_may_write_flush(struct pblk_rb *rb, unsigned int nr_entries,
 				   unsigned int *pos, struct bio *bio,
 				   int *io_ret)
@@ -443,15 +457,16 @@ int pblk_rb_may_write_user(struct pblk_rb *rb, struct bio *bio,
 			   unsigned int nr_entries, unsigned int *pos)
 {
 	struct pblk *pblk = container_of(rb, struct pblk, rwb);
-	int flush_done;
+	int io_ret;
 
 	spin_lock(&rb->w_lock);
-	if (!pblk_rl_user_may_insert(&pblk->rl, nr_entries)) {
+	io_ret = pblk_rl_user_may_insert(&pblk->rl, nr_entries);
+	if (io_ret) {
 		spin_unlock(&rb->w_lock);
-		return NVM_IO_REQUEUE;
+		return io_ret;
 	}
 
-	if (!pblk_rb_may_write_flush(rb, nr_entries, pos, bio, &flush_done)) {
+	if (!pblk_rb_may_write_flush(rb, nr_entries, pos, bio, &io_ret)) {
 		spin_unlock(&rb->w_lock);
 		return NVM_IO_REQUEUE;
 	}
@@ -459,7 +474,7 @@ int pblk_rb_may_write_user(struct pblk_rb *rb, struct bio *bio,
 	pblk_rl_user_in(&pblk->rl, nr_entries);
 	spin_unlock(&rb->w_lock);
 
-	return flush_done;
+	return io_ret;
 }
 
 /*
diff --git a/drivers/lightnvm/pblk-read.c b/drivers/lightnvm/pblk-read.c
index 292cbd290eea..8c85792bfa41 100644
--- a/drivers/lightnvm/pblk-read.c
+++ b/drivers/lightnvm/pblk-read.c
@@ -142,6 +142,7 @@ static void pblk_end_io_read(struct nvm_rq *rqd)
 #endif
 
 	pblk_free_rqd(pblk, rqd, READ);
+	atomic_dec(&pblk->inflight_io);
 }
 
 static int pblk_fill_partial_read_bio(struct pblk *pblk, struct nvm_rq *rqd,
@@ -347,6 +348,7 @@ int pblk_submit_read(struct pblk *pblk, struct bio *bio)
 	bio_get(bio);
 	if (bitmap_full(&read_bitmap, nr_secs)) {
 		bio_endio(bio);
+		atomic_inc(&pblk->inflight_io);
 		pblk_end_io_read(rqd);
 		return NVM_IO_OK;
 	}
@@ -516,6 +518,7 @@ int pblk_submit_read_gc(struct pblk *pblk, u64 *lba_list, void *data,
 				msecs_to_jiffies(PBLK_COMMAND_TIMEOUT_MS))) {
 		pr_err("pblk: GC read I/O timed out\n");
 	}
+	atomic_dec(&pblk->inflight_io);
 
 	if (rqd.error) {
 		atomic_long_inc(&pblk->read_failed_gc);
diff --git a/drivers/lightnvm/pblk-recovery.c b/drivers/lightnvm/pblk-recovery.c
index b9f2b40bd5a7..abf36f587477 100644
--- a/drivers/lightnvm/pblk-recovery.c
+++ b/drivers/lightnvm/pblk-recovery.c
@@ -300,7 +300,7 @@ static int pblk_recov_read_oob(struct pblk *pblk, struct pblk_line *line,
 		pr_err("pblk: L2P recovery read timed out\n");
 		return -EINTR;
 	}
-
+	atomic_dec(&pblk->inflight_io);
 	reinit_completion(&wait);
 
 	/* At this point, the read should not fail. If it does, it is a problem
@@ -415,6 +415,7 @@ static int pblk_recov_pad_oob(struct pblk *pblk, struct pblk_line *line,
 				msecs_to_jiffies(PBLK_COMMAND_TIMEOUT_MS))) {
 		pr_err("pblk: L2P recovery write timed out\n");
 	}
+	atomic_dec(&pblk->inflight_io);
 	reinit_completion(&wait);
 
 	left_line_ppas -= rq_ppas;
@@ -519,6 +520,7 @@ static int pblk_recov_scan_all_oob(struct pblk *pblk, struct pblk_line *line,
 				msecs_to_jiffies(PBLK_COMMAND_TIMEOUT_MS))) {
 		pr_err("pblk: L2P recovery read timed out\n");
 	}
+	atomic_dec(&pblk->inflight_io);
 	reinit_completion(&wait);
 
 	/* This should not happen since the read failed during normal recovery,
@@ -658,6 +660,7 @@ static int pblk_recov_scan_oob(struct pblk *pblk, struct pblk_line *line,
 				msecs_to_jiffies(PBLK_COMMAND_TIMEOUT_MS))) {
 		pr_err("pblk: L2P recovery read timed out\n");
 	}
+	atomic_dec(&pblk->inflight_io);
 	reinit_completion(&wait);
 
 	/* Reached the end of the written line */
@@ -954,9 +957,9 @@ struct pblk_line *pblk_recov_l2p(struct pblk *pblk)
 }
 
 /*
- * Pad until smeta can be read on current data line
+ * Pad current line
  */
-void pblk_recov_pad(struct pblk *pblk)
+int pblk_recov_pad(struct pblk *pblk)
 {
 	struct nvm_tgt_dev *dev = pblk->dev;
 	struct nvm_geo *geo = &dev->geo;
@@ -967,26 +970,33 @@ void pblk_recov_pad(struct pblk *pblk)
 	struct ppa_addr *ppa_list;
 	struct pblk_sec_meta *meta_list;
 	void *data;
+	int left_msecs;
+	int ret = 0;
 	dma_addr_t dma_ppa_list, dma_meta_list;
 
 	spin_lock(&l_mg->free_lock);
 	line = l_mg->data_line;
+	left_msecs = line->left_msecs;
 	spin_unlock(&l_mg->free_lock);
 
 	rqd = pblk_alloc_rqd(pblk, READ);
 	if (IS_ERR(rqd))
-		return;
+		return PTR_ERR(rqd);
 
 	meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL, &dma_meta_list);
-	if (!meta_list)
+	if (!meta_list) {
+		ret = -ENOMEM;
 		goto free_rqd;
+	}
 
 	ppa_list = (void *)(meta_list) + pblk_dma_meta_size;
 	dma_ppa_list = dma_meta_list + pblk_dma_meta_size;
 
 	data = kcalloc(pblk->max_write_pgs, geo->sec_size, GFP_KERNEL);
-	if (!data)
+	if (!data) {
+		ret = -ENOMEM;
 		goto free_meta_list;
+	}
 
 	p.ppa_list = ppa_list;
 	p.meta_list = meta_list;
@@ -995,12 +1005,13 @@ void pblk_recov_pad(struct pblk *pblk)
 	p.dma_ppa_list = dma_ppa_list;
 	p.dma_meta_list = dma_meta_list;
 
-	if (pblk_recov_pad_oob(pblk, line, p, line->left_msecs)) {
-		pr_err("pblk: Tear down padding failed\n");
+	ret = pblk_recov_pad_oob(pblk, line, p, left_msecs);
+	if (ret) {
+		pr_err("pblk: Tear down padding failed (%d)\n", ret);
 		goto free_data;
 	}
 
-	pblk_line_close(pblk, line);
+	pblk_line_close_meta(pblk, line);
 
 free_data:
 	kfree(data);
@@ -1008,4 +1019,6 @@ void pblk_recov_pad(struct pblk *pblk)
 	nvm_dev_dma_free(dev->parent, meta_list, dma_meta_list);
 free_rqd:
 	pblk_free_rqd(pblk, rqd, READ);
+
+	return ret;
 }
diff --git a/drivers/lightnvm/pblk-rl.c b/drivers/lightnvm/pblk-rl.c
index 52068a1807a8..2e6a5361baf0 100644
--- a/drivers/lightnvm/pblk-rl.c
+++ b/drivers/lightnvm/pblk-rl.c
@@ -23,11 +23,35 @@ static void pblk_rl_kick_u_timer(struct pblk_rl *rl)
 	mod_timer(&rl->u_timer, jiffies + msecs_to_jiffies(5000));
 }
 
+int pblk_rl_is_limit(struct pblk_rl *rl)
+{
+	int rb_space;
+
+	rb_space = atomic_read(&rl->rb_space);
+
+	return (rb_space == 0);
+}
+
 int pblk_rl_user_may_insert(struct pblk_rl *rl, int nr_entries)
 {
 	int rb_user_cnt = atomic_read(&rl->rb_user_cnt);
+	int rb_space = atomic_read(&rl->rb_space);
 
-	return (!(rb_user_cnt >= rl->rb_user_max));
+	if (unlikely(rb_space >= 0) && (rb_space - nr_entries < 0))
+		return NVM_IO_ERR;
+
+	if (rb_user_cnt >= rl->rb_user_max)
+		return NVM_IO_REQUEUE;
+
+	return NVM_IO_OK;
+}
+
+void pblk_rl_inserted(struct pblk_rl *rl, int nr_entries)
+{
+	int rb_space = atomic_read(&rl->rb_space);
+
+	if (unlikely(rb_space >= 0))
+		atomic_sub(nr_entries, &rl->rb_space);
 }
 
 int pblk_rl_gc_may_insert(struct pblk_rl *rl, int nr_entries)
@@ -190,10 +214,12 @@ void pblk_rl_init(struct pblk_rl *rl, int budget)
 	/* To start with, all buffer is available to user I/O writers */
 	rl->rb_budget = budget;
 	rl->rb_user_max = budget;
-	atomic_set(&rl->rb_user_cnt, 0);
 	rl->rb_gc_max = 0;
 	rl->rb_state = PBLK_RL_HIGH;
+
+	atomic_set(&rl->rb_user_cnt, 0);
 	atomic_set(&rl->rb_gc_cnt, 0);
+	atomic_set(&rl->rb_space, -1);
 
 	setup_timer(&rl->u_timer, pblk_rl_u_timer, (unsigned long)rl);
 
diff --git a/drivers/lightnvm/pblk-sysfs.c b/drivers/lightnvm/pblk-sysfs.c
index d9f7f13a38cc..22e6f2ad4aee 100644
--- a/drivers/lightnvm/pblk-sysfs.c
+++ b/drivers/lightnvm/pblk-sysfs.c
@@ -241,9 +241,10 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page)
 		geo->nr_luns, lm->blk_per_line, lm->sec_per_line);
 
 	sz += snprintf(page + sz, PAGE_SIZE - sz,
-		"lines:d:%d,l:%d-f:%d,m:%d,c:%d,b:%d,co:%d(d:%d,l:%d)t:%d\n",
+		"lines:d:%d,l:%d-f:%d,m:%d/%d,c:%d,b:%d,co:%d(d:%d,l:%d)t:%d\n",
 					cur_data, cur_log,
-					nr_free_lines, emeta_line_cnt,
+					nr_free_lines,
+					emeta_line_cnt, meta_weight,
 					closed_line_cnt,
 					bad, cor,
 					d_line_cnt, l_line_cnt,
@@ -257,7 +258,8 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page)
 	sz += snprintf(page + sz, PAGE_SIZE - sz,
 		"data (%d) cur:%d, left:%d, vsc:%d, s:%d, map:%d/%d (%d)\n",
 			cur_data, cur_sec, msecs, vsc, sec_in_line,
-			map_weight, lm->sec_per_line, meta_weight);
+			map_weight, lm->sec_per_line,
+			atomic_read(&pblk->inflight_io));
 
 	return sz;
 }
diff --git a/drivers/lightnvm/pblk-write.c b/drivers/lightnvm/pblk-write.c
index f071fb79e199..3e0b84937b90 100644
--- a/drivers/lightnvm/pblk-write.c
+++ b/drivers/lightnvm/pblk-write.c
@@ -171,6 +171,7 @@ static void pblk_end_io_write(struct nvm_rq *rqd)
 #endif
 
 	pblk_complete_write(pblk, rqd, c_ctx);
+	atomic_dec(&pblk->inflight_io);
 }
 
 static void pblk_end_io_write_meta(struct nvm_rq *rqd)
@@ -203,6 +204,8 @@ static void pblk_end_io_write_meta(struct nvm_rq *rqd)
 
 	bio_put(rqd->bio);
 	pblk_free_rqd(pblk, rqd, READ);
+
+	atomic_dec(&pblk->inflight_io);
 }
 
 static int pblk_alloc_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
@@ -254,7 +257,7 @@ static int pblk_setup_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
 		return ret;
 	}
 
-	if (likely(!atomic_read(&e_line->left_eblks) || !e_line))
+	if (likely(!e_line || !atomic_read(&e_line->left_eblks)))
 		pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, valid, 0);
 	else
 		pblk_map_erase_rq(pblk, rqd, c_ctx->sentry, lun_bitmap,
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index 862bca130144..8c7fd833990d 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -257,11 +257,13 @@ struct pblk_rl {
 				 */
 	int rb_budget;		/* Total number of entries available for I/O */
 	int rb_user_max;	/* Max buffer entries available for user I/O */
-	atomic_t rb_user_cnt;	/* User I/O buffer counter */
 	int rb_gc_max;		/* Max buffer entries available for GC I/O */
 	int rb_gc_rsv;		/* Reserved buffer entries for GC I/O */
 	int rb_state;		/* Rate-limiter current state */
+
+	atomic_t rb_user_cnt;	/* User I/O buffer counter */
 	atomic_t rb_gc_cnt;	/* GC I/O buffer counter */
+	atomic_t rb_space;	/* Space limit in case of reaching capacity */
 
 	int rsv_blocks;		/* Reserved blocks for GC */
 
@@ -529,6 +531,13 @@ struct pblk_addr_format {
 	u8	sec_offset;
 };
 
+enum {
+	PBLK_STATE_RUNNING = 0,
+	PBLK_STATE_STOPPING = 1,
+	PBLK_STATE_RECOVERING = 2,
+	PBLK_STATE_STOPPED = 3,
+};
+
 struct pblk {
 	struct nvm_tgt_dev *dev;
 	struct gendisk *disk;
@@ -546,6 +555,8 @@ struct pblk {
 
 	struct pblk_rb rwb;
 
+	int state;			/* pblk line state */
+
 	int min_write_pgs; /* Minimum amount of pages required by controller */
 	int max_write_pgs; /* Maximum amount of pages supported by controller */
 	int pgs_in_buffer; /* Number of pages that need to be held in buffer to
@@ -587,6 +598,8 @@ struct pblk {
 	atomic_long_t write_failed;
 	atomic_long_t erase_failed;
 
+	atomic_t inflight_io;		/* General inflight I/O counter */
+
 	struct task_struct *writer_ts;
 
 	/* Simple translation map of logical addresses to physical addresses.
@@ -640,6 +653,7 @@ void pblk_rb_write_entry_gc(struct pblk_rb *rb, void *data,
 			    struct pblk_w_ctx w_ctx, struct pblk_line *gc_line,
 			    unsigned int pos);
 struct pblk_w_ctx *pblk_rb_w_ctx(struct pblk_rb *rb, unsigned int pos);
+void pblk_rb_flush(struct pblk_rb *rb);
 
 void pblk_rb_sync_l2p(struct pblk_rb *rb);
 unsigned int pblk_rb_read_to_bio(struct pblk_rb *rb, struct nvm_rq *rqd,
@@ -675,7 +689,7 @@ void pblk_set_sec_per_write(struct pblk *pblk, int sec_per_write);
 int pblk_setup_w_rec_rq(struct pblk *pblk, struct nvm_rq *rqd,
 			struct pblk_c_ctx *c_ctx);
 void pblk_free_rqd(struct pblk *pblk, struct nvm_rq *rqd, int rw);
-void pblk_flush_writer(struct pblk *pblk);
+void pblk_wait_for_meta(struct pblk *pblk);
 struct ppa_addr pblk_get_lba_map(struct pblk *pblk, sector_t lba);
 void pblk_discard(struct pblk *pblk, struct bio *bio);
 void pblk_log_write_err(struct pblk *pblk, struct nvm_rq *rqd);
@@ -687,7 +701,7 @@ struct bio *pblk_bio_map_addr(struct pblk *pblk, void *data,
 			      gfp_t gfp_mask);
 struct pblk_line *pblk_line_get(struct pblk *pblk);
 struct pblk_line *pblk_line_get_first_data(struct pblk *pblk);
-struct pblk_line *pblk_line_replace_data(struct pblk *pblk);
+void pblk_line_replace_data(struct pblk *pblk);
 int pblk_line_recov_alloc(struct pblk *pblk, struct pblk_line *line);
 void pblk_line_recov_close(struct pblk *pblk, struct pblk_line *line);
 struct pblk_line *pblk_line_get_data(struct pblk *pblk);
@@ -697,7 +711,9 @@ int pblk_line_is_full(struct pblk_line *line);
 void pblk_line_free(struct pblk *pblk, struct pblk_line *line);
 void pblk_line_close_meta(struct pblk *pblk, struct pblk_line *line);
 void pblk_line_close(struct pblk *pblk, struct pblk_line *line);
+void pblk_line_close_meta_sync(struct pblk *pblk);
 void pblk_line_close_ws(struct work_struct *work);
+void pblk_pipeline_stop(struct pblk *pblk);
 void pblk_line_mark_bb(struct work_struct *work);
 void pblk_line_run_ws(struct pblk *pblk, struct pblk_line *line, void *priv,
 		      void (*work)(struct work_struct *),
@@ -778,7 +794,7 @@ int pblk_submit_read_gc(struct pblk *pblk, u64 *lba_list, void *data,
  */
 void pblk_submit_rec(struct work_struct *work);
 struct pblk_line *pblk_recov_l2p(struct pblk *pblk);
-void pblk_recov_pad(struct pblk *pblk);
+int pblk_recov_pad(struct pblk *pblk);
 __le64 *pblk_recov_get_lba_list(struct pblk *pblk, struct line_emeta *emeta);
 int pblk_recov_setup_rq(struct pblk *pblk, struct pblk_c_ctx *c_ctx,
 			struct pblk_rec_ctx *recovery, u64 *comp_bits,
@@ -811,6 +827,7 @@ int pblk_rl_high_thrs(struct pblk_rl *rl);
 int pblk_rl_low_thrs(struct pblk_rl *rl);
 unsigned long pblk_rl_nr_free_blks(struct pblk_rl *rl);
 int pblk_rl_user_may_insert(struct pblk_rl *rl, int nr_entries);
+void pblk_rl_inserted(struct pblk_rl *rl, int nr_entries);
 void pblk_rl_user_in(struct pblk_rl *rl, int nr_entries);
 int pblk_rl_gc_may_insert(struct pblk_rl *rl, int nr_entries);
 void pblk_rl_gc_in(struct pblk_rl *rl, int nr_entries);
@@ -818,6 +835,8 @@ void pblk_rl_out(struct pblk_rl *rl, int nr_user, int nr_gc);
 int pblk_rl_sysfs_rate_show(struct pblk_rl *rl);
 void pblk_rl_free_lines_inc(struct pblk_rl *rl, struct pblk_line *line);
 void pblk_rl_free_lines_dec(struct pblk_rl *rl, struct pblk_line *line);
+void pblk_rl_set_space_limit(struct pblk_rl *rl, int entries_left);
+int pblk_rl_is_limit(struct pblk_rl *rl);
 
 /*
  * pblk sysfs
-- 
2.7.4

Re: [PATCH 00/20] LightNVM: pblk patches for 4.13

[Jens Axboe]

On Mon, Jun 26 2017, Javier González wrote:
> Hi Matias,
> 
> Here you have the pblk patchset for this window.
> 
> Apart from small fixes for LightNVM core and pblk, there are three
> relevant changes:
> 
>  - Metadata for each line is no longer issued on a separate workqueue,
>    but instead, all I/Os are scheduled on the write thread. This allows
>    to have more control over LUN collisions. The result is that we can
>    use the full bandwidth of the device for user data. In the 4.12 pblk,
>    we use ~25% of the bandwidth for metadata.
> 
>  - The rate-limiter and GC have been tuned to keep the GC writer busy.
>    Also, capacity per line is guaranteed for GC I/O as we reach
>    capacity.
> 
>  - We have now a FTL state machine. This allows to fail gracefully to
>    user space in case of irrecoverable errors. This state machine will
>    be the base for the pblk's FTL log.
> 
> The patches apply into your for-4.13/core. You can also find them in:

Nope, they do not. Patch #7 fails, because it's not on top of the
bio_set changes that went in a week or two ago. I hand applied that one,
didn't find issues with the rest.

But please remember to ensure that it applies on top of the current
branch.

-- 
Jens Axboe

Re: [PATCH 00/20] LightNVM: pblk patches for 4.13

[Javier González]

[-- Attachment #1: Type: text/plain, Size: 1396 bytes --]

> On 27 Jun 2017, at 00.29, Jens Axboe <axboe@kernel.dk> wrote:
> 
> On Mon, Jun 26 2017, Javier González wrote:
>> Hi Matias,
>> 
>> Here you have the pblk patchset for this window.
>> 
>> Apart from small fixes for LightNVM core and pblk, there are three
>> relevant changes:
>> 
>> - Metadata for each line is no longer issued on a separate workqueue,
>>   but instead, all I/Os are scheduled on the write thread. This allows
>>   to have more control over LUN collisions. The result is that we can
>>   use the full bandwidth of the device for user data. In the 4.12 pblk,
>>   we use ~25% of the bandwidth for metadata.
>> 
>> - The rate-limiter and GC have been tuned to keep the GC writer busy.
>>   Also, capacity per line is guaranteed for GC I/O as we reach
>>   capacity.
>> 
>> - We have now a FTL state machine. This allows to fail gracefully to
>>   user space in case of irrecoverable errors. This state machine will
>>   be the base for the pblk's FTL log.
>> 
>> The patches apply into your for-4.13/core. You can also find them in:
> 
> Nope, they do not. Patch #7 fails, because it's not on top of the
> bio_set changes that went in a week or two ago. I hand applied that one,
> didn't find issues with the rest.
> 
> But please remember to ensure that it applies on top of the current
> branch.

Thanks Jens. Won't happen again.

Javier


[-- Attachment #2: Message signed with OpenPGP --]
[-- Type: application/pgp-signature, Size: 801 bytes --]

Re: [PATCH 08/20] lightnvm: pblk: sched. metadata on write thread

[Rakesh Pandit]

Hi Javier,

one small issue I found for error path while going through changes:

On Mon, Jun 26, 2017 at 11:57:17AM +0200, Javier González wrote:
..
> +static int pblk_lines_alloc_metadata(struct pblk *pblk)
> +{
> +	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
> +	struct pblk_line_meta *lm = &pblk->lm;
> +	int i;
> +
> +	/* smeta is always small enough to fit on a kmalloc memory allocation,
> +	 * emeta depends on the number of LUNs allocated to the pblk instance
> +	 */
> +	l_mg->smeta_alloc_type = PBLK_KMALLOC_META;
> +	for (i = 0; i < PBLK_DATA_LINES; i++) {
> +		l_mg->sline_meta[i] = kmalloc(lm->smeta_len, GFP_KERNEL);
> +		if (!l_mg->sline_meta[i])
> +			goto fail_free_smeta;

For this error path the the goto label at end doesn't free up
resources correctly.  It needs a

while (--index >= 0)...

logic with appropriate adjustment.

> +	}
> +
> +	/* emeta allocates three different buffers for managing metadata with
> +	 * in-memory and in-media layouts
> +	 */
> +	for (i = 0; i < PBLK_DATA_LINES; i++) {
> +		struct pblk_emeta *emeta;
> +
> +		emeta = kmalloc(sizeof(struct pblk_emeta), GFP_KERNEL);
> +		if (!emeta)
> +			goto fail_free_emeta;
> +
> +		if (lm->emeta_len[0] > KMALLOC_MAX_CACHE_SIZE) {
> +			l_mg->emeta_alloc_type = PBLK_VMALLOC_META;
> +
> +			emeta->buf = vmalloc(lm->emeta_len[0]);
> +			if (!emeta->buf) {
> +				kfree(emeta);
> +				goto fail_free_emeta;
> +			}
> +
> +			emeta->nr_entries = lm->emeta_sec[0];
> +			l_mg->eline_meta[i] = emeta;
> +		} else {
> +			l_mg->emeta_alloc_type = PBLK_KMALLOC_META;
> +
> +			emeta->buf = kmalloc(lm->emeta_len[0], GFP_KERNEL);
> +			if (!emeta->buf) {
> +				kfree(emeta);
> +				goto fail_free_emeta;
> +			}
> +
> +			emeta->nr_entries = lm->emeta_sec[0];
> +			l_mg->eline_meta[i] = emeta;
> +		}
> +	}
> +
> +	l_mg->vsc_list = kcalloc(l_mg->nr_lines, sizeof(__le32), GFP_KERNEL);
> +	if (!l_mg->vsc_list)
> +		goto fail_free_emeta;
> +
> +	for (i = 0; i < l_mg->nr_lines; i++)
> +		l_mg->vsc_list[i] = cpu_to_le32(EMPTY_ENTRY);
> +
> +	return 0;
> +
> +fail_free_emeta:
> +	while (--i >= 0) {
> +		vfree(l_mg->eline_meta[i]->buf);

This would need l_mg->emeta_alloc_type check to decide whether
allocation was done with kmalloc or vmalloc.

> +		kfree(&l_mg->eline_meta[i]);
> +	}
> +
> +fail_free_smeta:
> +	for (i = 0; i < PBLK_DATA_LINES; i++)
> +		pblk_mfree(&l_mg->sline_meta[i], l_mg->smeta_alloc_type);
> +
> +	return -ENOMEM;
> +}
> +

Thanks,

Re: [PATCH 08/20] lightnvm: pblk: sched. metadata on write thread

[Rakesh Pandit]

On Wed, Sep 20, 2017 at 09:28:34PM +0300, Rakesh Pandit wrote:
> Hi Javier,
> 
> one small issue I found for error path while going through changes:
> 
> On Mon, Jun 26, 2017 at 11:57:17AM +0200, Javier González wrote:
> ..
> > +static int pblk_lines_alloc_metadata(struct pblk *pblk)
> > +{
[..]
> > +		if (!l_mg->sline_meta[i])
> > +			goto fail_free_smeta;
> 
> For this error path the the goto label at end doesn't free up
> resources correctly.  It needs a
> 
> while (--index >= 0)...
> 
> logic with appropriate adjustment.
> 
> > +	}
[..]
> > +	if (!l_mg->vsc_list)
> > +		goto fail_free_emeta;
> > +
> > +	for (i = 0; i < l_mg->nr_lines; i++)
> > +		l_mg->vsc_list[i] = cpu_to_le32(EMPTY_ENTRY);
> > +
> > +	return 0;
> > +
> > +fail_free_emeta:
> > +	while (--i >= 0) {
> > +		vfree(l_mg->eline_meta[i]->buf);
> 
> This would need l_mg->emeta_alloc_type check to decide whether
> allocation was done with kmalloc or vmalloc.
> 
> > +		kfree(&l_mg->eline_meta[i]);
> > +	}
> > +
> > +fail_free_smeta:
> > +	for (i = 0; i < PBLK_DATA_LINES; i++)
> > +		pblk_mfree(&l_mg->sline_meta[i], l_mg->smeta_alloc_type);
> > +
> > +	return -ENOMEM;
> > +}
> > +
> 
> Thanks,

I failed to see earlier that it has been merged already.  Will post a
patch in a while.

Thanks,