[RFC PATCH v2] lightnvm: physical block device (pblk) target

[Javier GonzÃlez]

This patch introduces pblk, a new LightNVM target to work on an Open-Channel
SSD. pblk implements a fully associative, host-based flash translation layer
(FTL) that exposes a traditional block I/O interface.

In the initial version, pblk implements the following FTL functionality:

  - L2P Mapping: pblk maps logical addresses onto physical ones at a 4KB
  granurality. The L2P table resides entirely in the host memory.

  - Write Caching: In order to deal with media constrains, it is
  necessary to buffer writes.

  - Garbage Collection: pblk implements a cost-based garbage collection
  algorithm. As media blocks become full, pblk moves valid sectors to
  new blocks in order to free space.

  - I/O Rate Limiter: Since both user threads and GC can issue I/O, pblk
  implements a PID rate-limiter that controls the bandwidth available
  for user and GC I/O based on the device's capacity.

  - L2P Recovery: pblk stores enough redundant metadata on the media to
  recover the L2P table in case of power outage. In the current
  version, pblk provides a full-scan recovery mechanism.

  - Sysfs Interface: A sysfs file system interface is provided to allow
  user-space communication with pblk. This interface can be found at
  /dev/block/$INSTANCE_NAME/pblk/. Some of the exposed files are only
  available under NVM_DEBUG.

  - Multi-instance: Multiple pblk instances can be created on a single
  Open-Channel SSD. Each instance owns a portion of the device - both
  in terms of I/O bandwidth and capacity -, which guarantees I/O
  isolation across instances.

  - Recovery: pblk implements write and erase recovery. Recovery for
  read errors is delegated to the device.

Contributions to this patch:
 - Matias BjÃrling <matias@xxxxxxxxxxxx>
 - Simon A. F. Lund <slund@xxxxxxxxxxxx>
 - Young Tack Jin <youngtack.jin@xxxxxxxxx>

Signed-off-by: Javier GonzÃlez <javier@xxxxxxxxxxxx>
---
 Documentation/lightnvm/pblk.txt  |   21 +
 drivers/lightnvm/Kconfig         |   18 +
 drivers/lightnvm/Makefile        |    5 +
 drivers/lightnvm/pblk-cache.c    |  119 +++
 drivers/lightnvm/pblk-core.c     | 1539 ++++++++++++++++++++++++++++++++++++++
 drivers/lightnvm/pblk-gc.c       |  401 ++++++++++
 drivers/lightnvm/pblk-init.c     |  937 +++++++++++++++++++++++
 drivers/lightnvm/pblk-map.c      |  146 ++++
 drivers/lightnvm/pblk-rb.c       |  857 +++++++++++++++++++++
 drivers/lightnvm/pblk-read.c     |  512 +++++++++++++
 drivers/lightnvm/pblk-recovery.c |  142 ++++
 drivers/lightnvm/pblk-rl.c       |  219 ++++++
 drivers/lightnvm/pblk-sysfs.c    |  947 +++++++++++++++++++++++
 drivers/lightnvm/pblk-write.c    |  407 ++++++++++
 drivers/lightnvm/pblk.h          |  958 ++++++++++++++++++++++++
 15 files changed, 7228 insertions(+)
 create mode 100644 Documentation/lightnvm/pblk.txt
 create mode 100644 drivers/lightnvm/pblk-cache.c
 create mode 100644 drivers/lightnvm/pblk-core.c
 create mode 100644 drivers/lightnvm/pblk-gc.c
 create mode 100644 drivers/lightnvm/pblk-init.c
 create mode 100644 drivers/lightnvm/pblk-map.c
 create mode 100644 drivers/lightnvm/pblk-rb.c
 create mode 100644 drivers/lightnvm/pblk-read.c
 create mode 100644 drivers/lightnvm/pblk-recovery.c
 create mode 100644 drivers/lightnvm/pblk-rl.c
 create mode 100644 drivers/lightnvm/pblk-sysfs.c
 create mode 100644 drivers/lightnvm/pblk-write.c
 create mode 100644 drivers/lightnvm/pblk.h

diff --git a/Documentation/lightnvm/pblk.txt b/Documentation/lightnvm/pblk.txt
new file mode 100644
index 0000000..1040ed1
--- /dev/null
+++ b/Documentation/lightnvm/pblk.txt
@@ -0,0 +1,21 @@
+pblk: Physical Block Device Target
+==================================
+
+pblk implements a fully associative, host-based FTL that exposes a traditional
+block I/O interface. Its primary responsibilities are:
+
+  - Map logical addresses onto physical addresses (4KB granularity) in a
+    logical-to-physical (L2P) table.
+  - Maintain the integrity and consistency of the L2P table as well as its
+    recovery from normal tear down and power outage.
+  - Deal with controller- and media-specific constrains.
+  - Handle I/O errors.
+  - Implement garbage collection.
+  - Maintain consistency across the I/O stack during synchronization points.
+
+For more information please refer to:
+
+  http://lightnvm.io
+
+which maintains updated FAQs, manual pages, technical documentation, tools,
+contacts, etc.
diff --git a/drivers/lightnvm/Kconfig b/drivers/lightnvm/Kconfig
index 0527141..264ea3f 100644
--- a/drivers/lightnvm/Kconfig
+++ b/drivers/lightnvm/Kconfig
@@ -33,4 +33,22 @@ config NVM_RRPC
 	host. The target is implemented using a linear mapping table and
 	cost-based garbage collection. It is optimized for 4K IO sizes.
 
+config NVM_PBLK
+	tristate "Physical Block Device Open-Channel SSD target"
+	---help---
+	Allows an open-channel SSD to be exposed as a block device to the
+	host. The target assumes the device exposes raw flash and must be
+	explicitly managed by the host.
+
+	Please note the disk format is considered EXPERIMENTAL for now.
+
+config NVM_PBLK_NO_RECOV
+	bool "PBLK without L2P scan recovery"
+	depends on NVM_PBLK
+	---help---
+	Disables scan recovery when instantiating a new pblk target. Scan
+	recovery happens when the L2P table cannot be recovered from snapshot or
+	the snapshot is corrupt. Scan recovery scans the blocks owned by the
+	target and reconstructs the L2P table.
+
 endif # NVM
diff --git a/drivers/lightnvm/Makefile b/drivers/lightnvm/Makefile
index b2a39e2..82d1a11 100644
--- a/drivers/lightnvm/Makefile
+++ b/drivers/lightnvm/Makefile
@@ -4,3 +4,8 @@
 
 obj-$(CONFIG_NVM)		:= core.o
 obj-$(CONFIG_NVM_RRPC)		+= rrpc.o
+obj-$(CONFIG_NVM_PBLK)		+= pblk.o
+pblk-y				:= pblk-init.o pblk-core.o pblk-rb.o \
+				   pblk-write.o pblk-cache.o pblk-read.o \
+				   pblk-gc.o pblk-recovery.o pblk-map.o \
+				   pblk-rl.o pblk-sysfs.o
diff --git a/drivers/lightnvm/pblk-cache.c b/drivers/lightnvm/pblk-cache.c
new file mode 100644
index 0000000..2f6d7b2
--- /dev/null
+++ b/drivers/lightnvm/pblk-cache.c
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@xxxxxxxxxxxx>
+ *                  Matias Bjorling <matias@xxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * pblk-cache.c - pblk's write cache
+ */
+
+#include "pblk.h"
+
+int pblk_write_to_cache(struct pblk *pblk, struct bio *bio, unsigned long flags)
+{
+	sector_t lba = pblk_get_lba(bio);
+	struct pblk_w_ctx w_ctx;
+	int nr_entries = pblk_get_secs(bio);
+	unsigned int bpos, pos;
+	int i, ret;
+
+	/* Update the write buffer head (mem) with the entries that we can
+	 * write. The write in itself cannot fail, so there is no need to
+	 * rollback from here on.
+	 */
+retry:
+	ret = pblk_rb_may_write_user(&pblk->rwb, bio, nr_entries, &bpos);
+	if (ret == NVM_IO_REQUEUE) {
+		io_schedule();
+		goto retry;
+	}
+
+	if (unlikely(!bio_has_data(bio)))
+		goto out;
+
+	w_ctx.flags = flags;
+	w_ctx.paddr = 0;
+	ppa_set_empty(&w_ctx.ppa);
+
+	for (i = 0; i < nr_entries; i++) {
+		void *data = bio_data(bio);
+		struct ppa_addr ppa;
+
+		w_ctx.lba = lba + i;
+
+		pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + i);
+		ppa = pblk_rb_write_entry(&pblk->rwb, data, w_ctx, pos);
+
+		pblk_update_map_cache(pblk, w_ctx.lba, ppa);
+		bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
+	}
+
+#ifdef CONFIG_NVM_DEBUG
+	atomic_add(nr_entries, &pblk->inflight_writes);
+	atomic_add(nr_entries, &pblk->req_writes);
+#endif
+
+out:
+	pblk_write_kick(pblk);
+	return ret;
+}
+
+/*
+ * On GC the incoming lbas are not necessarily sequential. Also, some of the
+ * lbas might not be valid entries, which are marked as empty by the GC thread
+ */
+int pblk_write_gc_to_cache(struct pblk *pblk, void *data, u64 *lba_list,
+			   unsigned int nr_entries, unsigned int nr_rec_entries,
+			   struct pblk_line *gc_line, unsigned long flags)
+{
+	struct pblk_w_ctx w_ctx;
+	unsigned int bpos, pos;
+	int i, valid_entries;
+
+	/* Update the write buffer head (mem) with the entries that we can
+	 * write. The write in itself cannot fail, so there is no need to
+	 * rollback from here on.
+	 */
+retry:
+	if (!pblk_rb_may_write_gc(&pblk->rwb, nr_rec_entries, &bpos)) {
+		io_schedule();
+		goto retry;
+	}
+
+	w_ctx.flags = flags;
+	w_ctx.paddr = 0;
+	ppa_set_empty(&w_ctx.ppa);
+
+	for (i = 0, valid_entries = 0; i < nr_entries; i++) {
+		struct ppa_addr ppa;
+
+		if (lba_list[i] == ADDR_EMPTY)
+			continue;
+
+		w_ctx.lba = lba_list[i];
+
+		pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + valid_entries);
+		ppa = pblk_rb_write_entry(&pblk->rwb, data, w_ctx, pos);
+
+		pblk_update_map_gc(pblk, w_ctx.lba, ppa, gc_line);
+
+		data += PBLK_EXPOSED_PAGE_SIZE;
+		valid_entries++;
+	}
+
+#ifdef CONFIG_NVM_DEBUG
+	BUG_ON(nr_rec_entries != valid_entries);
+	atomic_add(valid_entries, &pblk->inflight_writes);
+	atomic_add(valid_entries, &pblk->recov_gc_writes);
+#endif
+
+	return NVM_IO_OK;
+}
diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
new file mode 100644
index 0000000..618cf89
--- /dev/null
+++ b/drivers/lightnvm/pblk-core.c
@@ -0,0 +1,1539 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@xxxxxxxxxxxx>
+ *                  Matias Bjorling <matias@xxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * pblk-core.c - pblk's core functionality
+ *
+ */
+
+#include "pblk.h"
+#include <linux/time.h>
+
+static void pblk_mark_bb(struct pblk *pblk, struct pblk_line *line,
+			 struct ppa_addr *ppa)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	int pos = pblk_ppa_to_pos(geo, *ppa);
+
+	pr_debug("pblk: erase failed: line:%d, pos:%d\n", line->id, pos);
+	inc_stat(pblk, &pblk->erase_failed, 0);
+
+	if (test_and_set_bit(pos, line->blk_bitmap))
+		pr_err("pblk: attempted to erase bb: line:%d, pos:%d\n",
+							line->id, pos);
+
+	pblk_line_run_ws(pblk, ppa, pblk_line_mark_bb);
+}
+
+static void __pblk_end_io_erase(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	struct pblk_line *line;
+
+	line = &pblk->lines[pblk_ppa_to_line(rqd->ppa_addr)];
+	atomic_dec(&line->left_seblks);
+
+	if (rqd->error) {
+		struct ppa_addr *ppa;
+
+		ppa = kmalloc(sizeof(struct ppa_addr), GFP_ATOMIC);
+		if (!ppa)
+			return;
+
+		*ppa = rqd->ppa_addr;
+		pblk_mark_bb(pblk, line, ppa);
+	}
+}
+
+/* Erase completion assumes that only one block is erased at the time */
+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);
+}
+
+static void pblk_end_io_sync(struct nvm_rq *rqd)
+{
+	struct completion *waiting = rqd->private;
+
+	complete(waiting);
+}
+
+static void pblk_page_invalidate(struct pblk *pblk, struct ppa_addr ppa)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct list_head *move_list = NULL;
+	struct pblk_line *line;
+	u64 paddr;
+	int line_id;
+
+#ifdef CONFIG_NVM_DEBUG
+	BUG_ON(nvm_addr_in_cache(ppa));
+	BUG_ON(ppa_empty(ppa));
+#endif
+
+	line_id = pblk_ppa_to_line(ppa);
+	line = &pblk->lines[line_id];
+
+	/* Lines being reclaimed (GC'ed) do not need to be invalidated. Before
+	 * the L2P table is modified with valid reclaimed sectors a check is
+	 * done to endure that newer updates are not overwritten.
+	 */
+	spin_lock(&line->lock);
+	if (line->state == PBLK_LINESTATE_GC ||
+					line->state == PBLK_LINESTATE_FREE) {
+		spin_unlock(&line->lock);
+		return;
+	}
+
+	paddr = pblk_ppa_to_line_addr(pblk, ppa);
+	if (test_and_set_bit(paddr, line->invalid_bitmap)) {
+		WARN_ONCE(1, "pblk: double invalidate\n");
+		spin_unlock(&line->lock);
+		return;
+	}
+	line->vsc--;
+
+	if (line->state == PBLK_LINESTATE_CLOSED)
+		move_list = pblk_line_gc_list(pblk, line);
+	spin_unlock(&line->lock);
+
+	if (move_list) {
+		spin_lock(&l_mg->gc_lock);
+		list_move_tail(&line->list, move_list);
+		spin_unlock(&l_mg->gc_lock);
+	}
+}
+
+static void pblk_invalidate_range(struct pblk *pblk, sector_t slba,
+				  unsigned int nr_secs)
+{
+	sector_t lba;
+
+	spin_lock(&pblk->trans_lock);
+	for (lba = slba; lba < slba + nr_secs; lba++) {
+		struct ppa_addr *ppa = &pblk->trans_map[lba];
+
+		if (!nvm_addr_in_cache(*ppa) && !ppa_empty(*ppa))
+			pblk_page_invalidate(pblk, *ppa);
+		ppa_set_empty(ppa);
+	}
+	spin_unlock(&pblk->trans_lock);
+}
+
+struct nvm_rq *pblk_alloc_rqd(struct pblk *pblk, int rw)
+{
+	mempool_t *pool;
+	struct nvm_rq *rqd;
+	int rq_size;
+
+	if (rw == WRITE) {
+		pool = pblk->w_rq_pool;
+		rq_size = pblk_w_rq_size;
+	} else {
+		pool = pblk->r_rq_pool;
+		rq_size = pblk_r_rq_size;
+	}
+
+	rqd = mempool_alloc(pool, GFP_KERNEL);
+	if (!rqd)
+		return ERR_PTR(-ENOMEM);
+
+	memset(rqd, 0, rq_size);
+	return rqd;
+}
+
+void pblk_free_rqd(struct pblk *pblk, struct nvm_rq *rqd, int rw)
+{
+	mempool_t *pool;
+
+	if (rw == WRITE)
+		pool = pblk->w_rq_pool;
+	else
+		pool = pblk->r_rq_pool;
+
+	mempool_free(rqd, pool);
+}
+
+void pblk_print_failed_rqd(struct pblk *pblk, struct nvm_rq *rqd, int error)
+{
+	int bit = -1;
+
+	if (rqd->nr_ppas ==  1) {
+		print_ppa(&rqd->ppa_addr, "rqd", error);
+		return;
+	}
+
+	while ((bit = find_next_bit((void *)&rqd->ppa_status, rqd->nr_ppas,
+						bit + 1)) < rqd->nr_ppas) {
+		print_ppa(&rqd->ppa_list[bit], "rqd", error);
+	}
+
+	pr_err("error:%d, ppa_status:%llx\n", error, rqd->ppa_status);
+}
+
+void pblk_bio_free_pages(struct pblk *pblk, struct bio *bio, int off,
+			 int nr_pages)
+{
+	struct bio_vec bv;
+	int i;
+
+	WARN_ON(off + nr_pages != bio->bi_vcnt);
+
+	bio_advance(bio, off * PBLK_EXPOSED_PAGE_SIZE);
+	for (i = off; i < nr_pages + off; i++) {
+		bv = bio->bi_io_vec[i];
+		mempool_free(bv.bv_page, pblk->page_pool);
+	}
+}
+
+int pblk_bio_add_pages(struct pblk *pblk, struct bio *bio, gfp_t flags,
+		       int nr_pages)
+{
+	struct request_queue *q = pblk->dev->q;
+	struct page *page;
+	int i, ret;
+
+	for (i = 0; i < nr_pages; i++) {
+		page = mempool_alloc(pblk->page_pool, flags);
+		if (!page)
+			goto err;
+
+		ret = bio_add_pc_page(q, bio, page, PBLK_EXPOSED_PAGE_SIZE, 0);
+		if (ret != PBLK_EXPOSED_PAGE_SIZE) {
+			pr_err("pblk: could not add page to bio\n");
+			mempool_free(page, pblk->page_pool);
+			goto err;
+		}
+	}
+
+	return 0;
+err:
+	pblk_bio_free_pages(pblk, bio, 0, i - 1);
+	return -1;
+}
+
+void pblk_write_timer_fn(unsigned long data)
+{
+	struct pblk *pblk = (struct pblk *)data;
+
+	/* kick the write thread every tick to flush outstanding data */
+	pblk_write_kick(pblk);
+}
+
+void pblk_end_bio_sync(struct bio *bio)
+{
+	struct completion *waiting = bio->bi_private;
+
+	complete(waiting);
+}
+
+void pblk_flush_writer(struct pblk *pblk)
+{
+	struct bio *bio;
+	int ret;
+	DECLARE_COMPLETION_ONSTACK(wait);
+
+	bio = bio_alloc(GFP_KERNEL, 1);
+	if (!bio)
+		return;
+
+	bio->bi_iter.bi_sector = 0; /* artificial 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)
+		wait_for_completion_io(&wait);
+	else if (ret != NVM_IO_DONE)
+		pr_err("pblk: tear down bio failed\n");
+
+	if (bio->bi_error)
+		pr_err("pblk: flush sync write failed (%u)\n", bio->bi_error);
+
+	bio_put(bio);
+}
+
+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;
+
+	if (!line->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) {
+		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) {
+		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) {
+		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) {
+		if (line->gc_group != PBLK_LINEGC_EMPTY) {
+			line->gc_group = PBLK_LINEGC_EMPTY;
+			move_list = &l_mg->gc_empty_list;
+		}
+	} else {
+		line->state = PBLK_LINESTATE_CORRUPT;
+		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->sec_in_line,
+						lm->high_thrs, lm->mid_thrs);
+	}
+
+	return move_list;
+}
+
+void pblk_discard(struct pblk *pblk, struct bio *bio)
+{
+	sector_t slba = pblk_get_lba(bio);
+	sector_t nr_secs = pblk_get_secs(bio);
+
+	pblk_invalidate_range(pblk, slba, nr_secs);
+}
+
+struct ppa_addr pblk_get_lba_map(struct pblk *pblk, sector_t lba)
+{
+	struct ppa_addr ppa;
+
+	spin_lock(&pblk->trans_lock);
+	ppa = pblk->trans_map[lba];
+	spin_unlock(&pblk->trans_lock);
+
+	return ppa;
+}
+
+void pblk_log_write_err(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	inc_stat(pblk, &pblk->write_failed, 1);
+#ifdef CONFIG_NVM_DEBUG
+	pblk_print_failed_rqd(pblk, rqd, rqd->error);
+#endif
+}
+
+void pblk_log_read_err(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	switch (rqd->error) {
+	case NVM_RSP_WARN_HIGHECC:
+		inc_stat(pblk, &pblk->read_high_ecc, 1);
+		break;
+	case NVM_RSP_ERR_FAILECC:
+		inc_stat(pblk, &pblk->read_failed, 1);
+		break;
+	case NVM_RSP_ERR_FAILCRC:
+		inc_stat(pblk, &pblk->read_failed, 1);
+		break;
+	case NVM_RSP_ERR_EMPTYPAGE:
+		inc_stat(pblk, &pblk->read_empty, 1);
+		break;
+	default:
+		pr_err("pblk: unknown read error:%d\n", rqd->error);
+	}
+#ifdef CONFIG_NVM_DEBUG
+	pblk_print_failed_rqd(pblk, rqd, rqd->error);
+#endif
+}
+
+int pblk_submit_io(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+
+#ifdef CONFIG_NVM_DEBUG
+	struct ppa_addr *ppa_list;
+
+	ppa_list = (rqd->nr_ppas > 1) ? rqd->ppa_list : &rqd->ppa_addr;
+	if (pblk_boundary_checks(dev, ppa_list, rqd->nr_ppas)) {
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	if (rqd->opcode == NVM_OP_PWRITE) {
+		struct pblk_line *line;
+		struct ppa_addr ppa;
+		int i;
+
+		for (i = 0; i < rqd->nr_ppas; i++) {
+			ppa = ppa_list[i];
+			line = &pblk->lines[pblk_ppa_to_line(ppa)];
+
+			spin_lock(&line->lock);
+			if (line->state != PBLK_LINESTATE_OPEN) {
+				pr_err("pblk: bad ppa: line:%d,state:%d\n",
+							line->id, line->state);
+				WARN_ON(1);
+				spin_unlock(&line->lock);
+				return -EINVAL;
+			}
+			spin_unlock(&line->lock);
+		}
+	}
+#endif
+	return nvm_submit_io(dev, rqd);
+}
+
+struct bio *pblk_bio_map_addr(struct pblk *pblk, void *data,
+			      unsigned int nr_secs, unsigned int len,
+			      gfp_t gfp_mask)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	void *kaddr = data;
+	struct page *page;
+	struct bio *bio;
+	int i, ret;
+
+	if (l_mg->emeta_alloc_type == PBLK_KMALLOC_META)
+		return bio_map_kern(dev->q, kaddr, len, gfp_mask);
+
+	bio = bio_kmalloc(gfp_mask, nr_secs);
+	if (!bio)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < nr_secs; i++) {
+		page = vmalloc_to_page(kaddr);
+		if (!page) {
+			pr_err("pblk: could not map vmalloc emeta\n");
+			bio_put(bio);
+			bio = ERR_PTR(-ENOMEM);
+			goto out;
+		}
+
+		ret = bio_add_pc_page(dev->q, bio, page, PAGE_SIZE, 0);
+		if (ret != PAGE_SIZE) {
+			pr_err("pblk: could not add page to emeta bio\n");
+			bio_put(bio);
+			bio = ERR_PTR(-ENOMEM);
+			goto out;
+		}
+
+		kaddr += PAGE_SIZE;
+	}
+
+out:
+	return bio;
+}
+
+int pblk_calc_secs(struct pblk *pblk, unsigned long secs_avail,
+		    unsigned long secs_to_flush)
+{
+	int max = pblk->max_write_pgs;
+	int min = pblk->min_write_pgs;
+	int secs_to_sync = 0;
+
+	if (secs_avail >= max)
+		secs_to_sync = max;
+	else if (secs_avail >= min)
+		secs_to_sync = min * (secs_avail / min);
+	else if (secs_to_flush)
+		secs_to_sync = min;
+
+	return secs_to_sync;
+}
+
+static u64 __pblk_alloc_page(struct pblk *pblk, struct pblk_line *line,
+			     int nr_secs)
+{
+	u64 addr;
+	int i;
+
+	/* logic error: ppa out-of-bounds */
+	BUG_ON(line->cur_sec + nr_secs > pblk->lm.sec_per_line);
+
+	line->cur_sec = addr = find_next_zero_bit(line->map_bitmap,
+					pblk->lm.sec_per_line, line->cur_sec);
+	for (i = 0; i < nr_secs; i++, line->cur_sec++)
+		WARN_ON(test_and_set_bit(line->cur_sec, line->map_bitmap));
+
+	return addr;
+}
+
+u64 pblk_alloc_page(struct pblk *pblk, struct pblk_line *line, int nr_secs)
+{
+	u64 addr;
+
+	/* Lock needed in case a write fails and a recovery needs to remap
+	 * failed write buffer entries
+	 */
+	spin_lock(&line->lock);
+	addr = __pblk_alloc_page(pblk, line, nr_secs);
+	line->left_msecs -= nr_secs;
+
+#ifdef CONFIG_NVM_DEBUG
+	BUG_ON(line->left_msecs < 0);
+#endif
+	spin_unlock(&line->lock);
+
+	return addr;
+}
+
+/*
+ * 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)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct bio *bio;
+	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 id = line->id;
+	int rq_ppas, rq_len;
+	int cmd_op, bio_op;
+	int flags;
+	int i, j;
+	int ret;
+	DECLARE_COMPLETION_ONSTACK(wait);
+
+	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;
+
+	ppa_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL, &dma_ppa_list);
+	if (!ppa_list)
+		return -ENOMEM;
+
+next_rq:
+	memset(&rqd, 0, sizeof(struct nvm_rq));
+
+	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);
+	if (IS_ERR(bio)) {
+		ret = PTR_ERR(bio);
+		goto free_rqd_dma;
+	}
+
+	bio->bi_iter.bi_sector = 0; /* artificial bio */
+	bio_set_op_attrs(bio, bio_op, 0);
+	bio->bi_private = &wait;
+	bio->bi_end_io = pblk_end_bio_sync;
+
+	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;
+
+	if (dir == WRITE) {
+		for (i = 0; i < rqd.nr_ppas; ) {
+			paddr = __pblk_alloc_page(pblk, line, min);
+			for (j = 0; j < min; j++, i++, paddr++)
+				rqd.ppa_list[i] =
+					addr_to_gen_ppa(pblk, paddr, id);
+		}
+	} else {
+		for (i = 0; i < rqd.nr_ppas; ) {
+			struct ppa_addr ppa = addr_to_gen_ppa(pblk, paddr, id);
+			int pos = pblk_ppa_to_pos(geo, ppa);
+
+			while (test_bit(pos, line->blk_bitmap)) {
+				paddr += min;
+				ppa = addr_to_gen_ppa(pblk, paddr, id);
+				pos = pblk_ppa_to_pos(geo, ppa);
+			}
+
+			for (j = 0; j < min; j++, i++, paddr++)
+				rqd.ppa_list[i] =
+					addr_to_gen_ppa(pblk, paddr, line->id);
+		}
+	}
+
+	ret = pblk_submit_io(pblk, &rqd);
+	if (ret) {
+		pr_err("pblk: emeta I/O submission failed: %d\n", ret);
+		bio_put(bio);
+		goto free_rqd_dma;
+	}
+	wait_for_completion_io(&wait);
+	reinit_completion(&wait);
+
+	if (rqd.error) {
+		if (dir == WRITE)
+			pblk_log_write_err(pblk, &rqd);
+		else
+			pblk_log_read_err(pblk, &rqd);
+	}
+#ifdef CONFIG_NVM_DEBUG
+	else
+		BUG_ON(rqd.bio->bi_error);
+#endif
+
+	bio_put(bio);
+
+	emeta += rq_len;
+	left_ppas -= rq_ppas;
+	if (left_ppas)
+		goto next_rq;
+free_rqd_dma:
+	nvm_dev_dma_free(dev->parent, ppa_list, dma_ppa_list);
+	return ret;
+}
+
+static int pblk_line_submit_smeta_io(struct pblk *pblk, struct pblk_line *line,
+				     u64 paddr, int dir)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct bio *bio;
+	struct nvm_rq rqd;
+	u64 *lba_list = NULL;
+	int i, ret;
+	int cmd_op, bio_op;
+	int flags;
+	DECLARE_COMPLETION_ONSTACK(wait);
+
+	if (dir == WRITE) {
+		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);
+	} else if (dir == READ) {
+		bio_op = REQ_OP_READ;
+		cmd_op = NVM_OP_PREAD;
+		flags = pblk_set_read_mode(pblk);
+	} else
+		return -EINVAL;
+
+	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)
+		return -ENOMEM;
+
+	bio = bio_map_kern(dev->q, line->smeta, lm->smeta_len, GFP_KERNEL);
+	if (IS_ERR(bio)) {
+		ret = PTR_ERR(bio);
+		goto free_ppa_list;
+	}
+
+	bio->bi_iter.bi_sector = 0; /* artificial bio */
+	bio_set_op_attrs(bio, bio_op, 0);
+	bio->bi_private = &wait;
+	bio->bi_end_io = pblk_end_bio_sync;
+
+	rqd.bio = bio;
+	rqd.opcode = cmd_op;
+	rqd.flags = flags;
+	rqd.nr_ppas = lm->smeta_sec;
+
+	for (i = 0; i < lm->smeta_sec; i++, paddr++) {
+		rqd.ppa_list[i] = addr_to_gen_ppa(pblk, paddr, line->id);
+		if (dir == WRITE)
+			lba_list[paddr] = ADDR_EMPTY;
+	}
+
+	/*
+	 * This I/O is sent by the write thread when a line is replace. Since
+	 * the write thread is the only one sending write and erase commands,
+	 * there is no need to take the LUN semaphore.
+	 */
+	ret = pblk_submit_io(pblk, &rqd);
+	if (ret) {
+		pr_err("pblk: smeta I/O submission failed: %d\n", ret);
+		bio_put(bio);
+		goto free_bio;
+	}
+	wait_for_completion_io(&wait);
+
+	if (rqd.error) {
+		if (dir == WRITE)
+			pblk_log_write_err(pblk, &rqd);
+		else
+			pblk_log_read_err(pblk, &rqd);
+	}
+#ifdef CONFIG_NVM_DEBUG
+	else
+		BUG_ON(rqd.bio->bi_error);
+#endif
+
+free_bio:
+	bio_put(bio);
+free_ppa_list:
+	nvm_dev_dma_free(dev->parent, rqd.ppa_list, rqd.dma_ppa_list);
+
+	return ret;
+}
+
+int pblk_line_read_smeta(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;
+	u64 bpaddr;
+	int bit;
+
+	bit = find_first_zero_bit(line->blk_bitmap, lm->blk_per_line);
+	if (unlikely(bit >= lm->blk_per_line)) {
+		pr_err("pblk: corrupted line %d\n", line->id);
+		return -EFAULT;
+	}
+
+	bpaddr = bit * geo->sec_per_blk;
+
+	return pblk_line_submit_smeta_io(pblk, line, bpaddr, READ);
+}
+
+int pblk_line_read_emeta(struct pblk *pblk, struct pblk_line *line)
+{
+	return pblk_line_submit_emeta_io(pblk, line, line->emeta_ssec, READ);
+}
+
+static int pblk_alloc_e_rq(struct pblk *pblk, struct nvm_rq *rqd,
+			   struct ppa_addr ppa)
+{
+	rqd->opcode = NVM_OP_ERASE;
+	rqd->ppa_addr = ppa;
+	rqd->nr_ppas = 1;
+	rqd->flags = pblk_set_progr_mode(pblk, ERASE);
+	rqd->bio = NULL;
+
+	return 0;
+}
+
+static int pblk_blk_erase_sync(struct pblk *pblk, struct ppa_addr ppa)
+{
+	struct nvm_rq rqd;
+	int ret;
+	DECLARE_COMPLETION_ONSTACK(wait);
+
+	memset(&rqd, 0, sizeof(struct nvm_rq));
+
+	if (pblk_alloc_e_rq(pblk, &rqd, ppa))
+		return -ENOMEM;
+
+	rqd.end_io = pblk_end_io_sync;
+	rqd.private = &wait;
+
+	/* The write thread schedules erases so that it minimizes disturbances
+	 * with writes. Thus, there is no need to take the LUN semaphore.
+	 */
+	ret = pblk_submit_io(pblk, &rqd);
+	if (ret) {
+		struct nvm_tgt_dev *dev = pblk->dev;
+		struct nvm_geo *geo = &dev->geo;
+
+		pr_err("pblk: could not sync erase line:%llu,blk:%llu\n",
+			pblk_ppa_to_line(ppa), pblk_ppa_to_pos(geo, ppa));
+
+		rqd.error = ret;
+		goto out;
+	}
+	wait_for_completion_io(&wait);
+
+out:
+	rqd.private = pblk;
+	__pblk_end_io_erase(pblk, &rqd);
+
+	return 0;
+}
+
+static 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;
+
+	/* Erase one block at the time and only erase good blocks */
+	while ((bit = find_next_zero_bit(line->erase_bitmap, lm->blk_per_line,
+						bit + 1)) < lm->blk_per_line) {
+		ppa = pblk->luns[bit].bppa; /* set ch and lun */
+		ppa.g.blk = line->id;
+
+		/* If the erase fails, the block is bad and should be marked */
+		line->left_eblks--;
+		WARN_ON(test_and_set_bit(bit, line->erase_bitmap));
+
+		if (pblk_blk_erase_sync(pblk, ppa))
+			return -ENOMEM;
+	}
+
+	return 0;
+}
+
+/* For now lines are always assumed full lines. Thus, smeta former and current
+ * lun bitmaps are omitted.
+ */
+static int pblk_line_setup(struct pblk *pblk, struct pblk_line *line,
+			   struct pblk_line *cur, int line_type)
+{
+	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;
+	u32 crc = ~(u32)0;
+	int nr_bb = 0;
+	int slun;
+	u64 off;
+	int bit;
+
+	/* After erasing the line, we risk having an invalid line */
+	bit = find_first_zero_bit(line->blk_bitmap, lm->blk_per_line);
+	if (unlikely(bit >= lm->blk_per_line)) {
+		spin_lock(&l_mg->free_lock);
+		spin_lock(&line->lock);
+		line->state = PBLK_LINESTATE_BAD;
+		spin_unlock(&line->lock);
+
+		list_add_tail(&line->list, &l_mg->bad_list);
+		spin_unlock(&l_mg->free_lock);
+
+		pr_debug("pblk: line %d is bad\n", line->id);
+		return 0;
+	}
+
+	line->type = line_type;
+
+	/* Run-time metadata */
+	line->lun_bitmap = ((void *)(smeta)) + sizeof(struct line_smeta);
+
+	/* Mark LUNs allocated in this line (all for now) */
+	line->sec_in_line = lm->sec_per_line;
+	bitmap_set(line->lun_bitmap, 0, lm->lun_bitmap_len);
+	slun = find_first_bit(line->lun_bitmap, lm->lun_bitmap_len);
+
+	/* Start metadata */
+	smeta->nr_luns = geo->nr_luns;
+	smeta->line_type = line->type;
+	smeta->id = line->id;
+	smeta->slun = slun;
+	smeta->seq_nr = line->seq_nr;
+	smeta->smeta_len = lm->smeta_len;
+
+	/* Fill metadata among lines */
+	if (likely(cur)) {
+		memcpy(line->lun_bitmap, cur->lun_bitmap, lm->lun_bitmap_len);
+		smeta->p_id = cur->id;
+		smeta->p_slun =
+			find_first_bit(cur->lun_bitmap, lm->lun_bitmap_len);
+		cur->emeta->n_id = line->id;
+		cur->emeta->n_slun =
+			find_first_bit(line->lun_bitmap, lm->lun_bitmap_len);
+	} else {
+		smeta->p_id = PBLK_LINE_EMPTY;
+		smeta->p_slun = PBLK_LINE_EMPTY;
+	}
+
+	crc = crc32_le(crc, (unsigned char *)smeta + sizeof(crc),
+					lm->smeta_len - sizeof(crc));
+	smeta->crc = crc;
+
+	/* End metadata */
+	emeta->nr_luns = geo->nr_luns;
+	emeta->line_type = line->type;
+	emeta->id = line->id;
+	emeta->slun = slun;
+	emeta->seq_nr = line->seq_nr;
+	emeta->nr_lbas = lm->sec_per_line - lm->emeta_sec - lm->smeta_sec;
+	emeta->n_id = PBLK_LINE_EMPTY;
+	emeta->n_slun = PBLK_LINE_EMPTY;
+	emeta->emeta_len = lm->emeta_len;
+	emeta->crc = 0;
+
+	/* Capture bad block information on line mapping bitmaps */
+	bit = -1;
+	while ((bit = find_next_bit(line->blk_bitmap, lm->blk_per_line,
+					bit + 1)) < lm->blk_per_line) {
+		off = bit * geo->sec_per_pl;
+		bitmap_shift_left(l_mg->bb_aux, l_mg->bb_template, off,
+							lm->sec_per_line);
+		bitmap_or(line->map_bitmap, line->map_bitmap, l_mg->bb_aux,
+							lm->sec_per_line);
+		line->sec_in_line -= geo->sec_per_blk;
+		if (bit >= lm->emeta_bb)
+			nr_bb++;
+	}
+
+	/* 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;
+	line->cur_sec = off + lm->smeta_sec;
+
+	bitmap_copy(line->invalid_bitmap, line->map_bitmap, lm->sec_per_line);
+
+	if (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;
+	}
+
+	/* Mark emeta metadata sectors as bad sectors. We need to consider bad
+	 * 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);
+	while (nr_bb) {
+		off -= geo->sec_per_pl;
+		if (!test_bit(off, line->invalid_bitmap)) {
+			bitmap_set(line->invalid_bitmap, off, geo->sec_per_pl);
+			nr_bb--;
+		}
+	}
+
+	line->sec_in_line -= lm->emeta_sec;
+	line->emeta_ssec = off;
+	line->vsc = line->left_ssecs = line->left_msecs = line->sec_in_line;
+
+#ifdef CONFIG_NVM_DEBUG
+	BUG_ON(lm->sec_per_line - line->sec_in_line !=
+		bitmap_weight(line->invalid_bitmap, lm->sec_per_line));
+#endif
+
+	return 1;
+}
+
+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;
+
+retry_get:
+	if (list_empty(&l_mg->free_list)) {
+		pr_err("pblk: no free lines\n");
+		goto out;
+	}
+
+	line = list_first_entry(&l_mg->free_list, struct pblk_line, list);
+	list_del(&line->list);
+
+	/* Bad blocks do not need to be erased */
+	bitmap_copy(line->erase_bitmap, line->blk_bitmap, lm->blk_per_line);
+	line->left_eblks = line->blk_in_line;
+	atomic_set(&line->left_seblks, line->left_eblks);
+
+	bit = find_first_zero_bit(line->blk_bitmap, lm->blk_per_line);
+	if (unlikely(bit >= lm->blk_per_line)) {
+		spin_lock(&l_mg->free_lock);
+		spin_lock(&line->lock);
+		line->state = PBLK_LINESTATE_BAD;
+		spin_unlock(&line->lock);
+
+		list_add_tail(&line->list, &l_mg->bad_list);
+		spin_unlock(&l_mg->free_lock);
+
+		pr_err("pblk: line %d is bad\n", line->id);
+		goto retry_get;
+	}
+
+	spin_lock(&line->lock);
+	BUG_ON(line->state != PBLK_LINESTATE_FREE);
+	line->state = PBLK_LINESTATE_OPEN;
+	spin_unlock(&line->lock);
+
+	kref_init(&line->ref);
+
+out:
+	return line;
+}
+
+struct pblk_line *pblk_line_get_first_data(struct pblk *pblk)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_line *line;
+	unsigned long *b, *p;
+	int meta_line;
+
+	b = mempool_alloc(pblk->line_meta_pool, GFP_KERNEL);
+	if (!b)
+		return NULL;
+	memset(b, 0, lm->sec_bitmap_len);
+
+	p = mempool_alloc(pblk->line_meta_pool, GFP_KERNEL);
+	if (!p)
+		goto fail_free_meta_bitmap;
+
+	spin_lock(&l_mg->free_lock);
+	line = pblk_line_get(pblk);
+	if (!line) {
+		spin_unlock(&l_mg->free_lock);
+		goto fail_free_invalid_bitmap;
+	}
+
+	line->map_bitmap = b;
+	line->invalid_bitmap = p;
+
+	line->seq_nr = l_mg->d_seq_nr++;
+	l_mg->data_line = line;
+	l_mg->nr_free_lines--;
+
+	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;
+	spin_unlock(&l_mg->free_lock);
+
+	if (pblk_line_erase(pblk, line))
+		goto fail_free_invalid_bitmap;
+
+	pblk_rl_free_lines_dec(&pblk->rl, line);
+
+retry_setup:
+	if (!pblk_line_setup(pblk, line, NULL, PBLK_LINETYPE_DATA)) {
+		struct pblk_line *retry_line;
+
+		spin_lock(&l_mg->free_lock);
+		retry_line = pblk_line_get(pblk);
+
+		retry_line->smeta = line->smeta;
+		retry_line->emeta = line->emeta;
+		retry_line->meta_line = line->meta_line;
+		retry_line->map_bitmap = b;
+		retry_line->invalid_bitmap = p;
+
+		line->map_bitmap = NULL;
+		line->invalid_bitmap = NULL;
+		line->smeta = NULL;
+		line->emeta = NULL;
+		spin_unlock(&l_mg->free_lock);
+
+		if (pblk_line_erase(pblk, retry_line))
+			pr_debug("pblk: only one data line available\n");
+
+		pblk_rl_free_lines_dec(&pblk->rl, retry_line);
+
+		l_mg->data_line = retry_line;
+		line = retry_line;
+		goto retry_setup;
+	}
+
+	return line;
+
+fail_free_invalid_bitmap:
+	mempool_free(p, pblk->line_meta_pool);
+fail_free_meta_bitmap:
+	mempool_free(b, pblk->line_meta_pool);
+
+	return NULL;
+}
+
+static struct pblk_line *__pblk_line_get_next_data(struct pblk *pblk,
+						   struct pblk_line_mgmt *l_mg,
+						   unsigned long *b,
+						   unsigned long *p)
+{
+	struct pblk_line *line;
+
+	line = pblk_line_get(pblk);
+	if (!line) {
+		l_mg->data_next = NULL;
+		return NULL;
+	}
+
+	line->map_bitmap = b;
+	line->invalid_bitmap = p;
+
+	line->seq_nr = l_mg->d_seq_nr++;
+	l_mg->data_next = line;
+	l_mg->nr_free_lines--;
+
+	return line;
+}
+
+struct pblk_line *pblk_line_get_next_data(struct pblk *pblk)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_line *line;
+	unsigned long *b, *p;
+
+	b = mempool_alloc(pblk->line_meta_pool, GFP_KERNEL);
+	if (!b)
+		return NULL;
+	memset(b, 0, lm->sec_bitmap_len);
+
+	p = mempool_alloc(pblk->line_meta_pool, GFP_KERNEL);
+	if (!p) {
+		mempool_free(b, pblk->line_meta_pool);
+		return NULL;
+	}
+
+	spin_lock(&l_mg->free_lock);
+	line = __pblk_line_get_next_data(pblk, l_mg, b, p);
+	spin_unlock(&l_mg->free_lock);
+
+	return line;
+}
+
+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 long *b, *p;
+	unsigned int left_seblks;
+	int meta_line;
+
+	b = mempool_alloc(pblk->line_meta_pool, GFP_KERNEL);
+	if (!b)
+		return NULL;
+	memset(b, 0, lm->sec_bitmap_len);
+
+	p = mempool_alloc(pblk->line_meta_pool, GFP_KERNEL);
+	if (!p) {
+		mempool_free(b, pblk->line_meta_pool);
+		return NULL;
+	}
+
+	cur = l_mg->data_line;
+	new = l_mg->data_next;
+	if (!new)
+		return NULL;
+	l_mg->data_line = new;
+
+retry_line:
+	left_seblks = atomic_read(&new->left_seblks);
+	if (left_seblks) {
+		/* If line is not fully erased, erase it */
+		if (new->left_eblks) {
+			if (pblk_line_erase(pblk, new))
+				return NULL;
+		} else {
+			io_schedule();
+		}
+		goto retry_line;
+	}
+
+	spin_lock(&l_mg->free_lock);
+#ifdef CONFIG_NVM_DEBUG
+	BUG_ON(!bitmap_full(new->erase_bitmap, lm->blk_per_line));
+#endif
+
+	l_mg->data_next = __pblk_line_get_next_data(pblk, l_mg, b, p);
+	if (!l_mg->data_next)
+		pr_debug("pblk: using last line\n");
+
+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);
+		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);
+	spin_unlock(&l_mg->free_lock);
+
+	pblk_rl_free_lines_dec(&pblk->rl, new);
+
+retry_setup:
+	if (!pblk_line_setup(pblk, new, cur, PBLK_LINETYPE_DATA)) {
+		struct pblk_line *retry_line;
+
+		spin_lock(&l_mg->free_lock);
+		retry_line = pblk_line_get(pblk);
+
+		retry_line->smeta = new->smeta;
+		retry_line->emeta = new->emeta;
+		retry_line->meta_line = new->meta_line;
+		retry_line->map_bitmap = new->map_bitmap;
+		retry_line->invalid_bitmap = new->invalid_bitmap;
+
+		new->map_bitmap = NULL;
+		new->invalid_bitmap = NULL;
+		new->smeta = NULL;
+		new->emeta = NULL;
+		spin_unlock(&l_mg->free_lock);
+
+		pblk_rl_free_lines_dec(&pblk->rl, retry_line);
+		if (pblk_line_erase(pblk, retry_line))
+			pr_debug("pblk: allocating last line\n");
+
+		l_mg->data_line = retry_line;
+		new = retry_line;
+		goto retry_setup;
+	}
+
+	return new;
+}
+
+void pblk_line_put(struct kref *ref)
+{
+	struct pblk_line *line = container_of(ref, struct pblk_line, ref);
+	struct pblk *pblk = line->pblk;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+
+	spin_lock(&line->lock);
+	BUG_ON(line->state != PBLK_LINESTATE_GC);
+	line->state = PBLK_LINESTATE_FREE;
+	line->gc_group = PBLK_LINEGC_NONE;
+	pblk_line_free(pblk, line);
+	spin_unlock(&line->lock);
+
+	spin_lock(&l_mg->free_lock);
+	list_add_tail(&line->list, &l_mg->free_list);
+	l_mg->nr_free_lines++;
+	spin_unlock(&l_mg->free_lock);
+
+	pblk_rl_free_lines_inc(&pblk->rl, line);
+}
+
+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);
+	if (!rqd)
+		return -ENOMEM;
+
+	memset(rqd, 0, pblk_r_rq_size);
+
+	if (pblk_alloc_e_rq(pblk, rqd, ppa))
+		return -ENOMEM;
+
+	rqd->end_io = pblk_end_io_erase;
+	rqd->private = pblk;
+
+	/* The write thread schedules erases so that it minimizes disturbances
+	 * with writes. Thus, there is no need to take the LUN semaphore.
+	 */
+	err = pblk_submit_io(pblk, rqd);
+	if (err) {
+		struct nvm_tgt_dev *dev = pblk->dev;
+		struct nvm_geo *geo = &dev->geo;
+
+		pr_err("pblk: could not async erase line:%llu,blk:%llu\n",
+			pblk_ppa_to_line(ppa), pblk_ppa_to_pos(geo, ppa));
+	}
+
+	return 0;
+}
+
+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)
+{
+	return pblk->l_mg.data_next;
+}
+
+int pblk_line_is_full(struct pblk_line *line)
+{
+	return (line->left_msecs == 0);
+}
+
+void pblk_line_free(struct pblk *pblk, struct pblk_line *line)
+{
+	if (line->map_bitmap)
+		mempool_free(line->map_bitmap, pblk->line_meta_pool);
+	if (line->invalid_bitmap)
+		mempool_free(line->invalid_bitmap, pblk->line_meta_pool);
+
+	line->map_bitmap = NULL;
+	line->invalid_bitmap = NULL;
+}
+
+void pblk_line_close(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_meta *lm = &pblk->lm;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line *line = line_ws->priv;
+	struct list_head *move_list;
+	u32 crc = ~(u32)0;
+
+	crc = crc32_le(crc, (unsigned char *)line->emeta + sizeof(crc),
+					lm->emeta_len - sizeof(crc));
+	line->emeta->crc = cpu_to_le32(crc);
+
+	if (pblk_line_submit_emeta_io(pblk, line, line->cur_sec, WRITE))
+		pr_err("pblk: line %d close I/O failed\n", line->id);
+
+#ifdef CONFIG_NVM_DEBUG
+	BUG_ON(!bitmap_full(line->map_bitmap, line->sec_in_line));
+#endif
+
+	spin_lock(&l_mg->free_lock);
+	WARN_ON(!test_and_clear_bit(line->meta_line, &l_mg->meta_bitmap));
+	spin_unlock(&l_mg->free_lock);
+
+	spin_lock(&line->lock);
+	WARN_ON(line->state != PBLK_LINESTATE_OPEN);
+	line->state = PBLK_LINESTATE_CLOSED;
+	move_list = pblk_line_gc_list(pblk, line);
+	BUG_ON(!move_list);
+	spin_unlock(&line->lock);
+
+	spin_lock(&l_mg->gc_lock);
+	list_add_tail(&line->list, move_list);
+	spin_unlock(&l_mg->gc_lock);
+
+	mempool_free(line->map_bitmap, pblk->line_meta_pool);
+	line->map_bitmap = NULL;
+	line->smeta = NULL;
+	line->emeta = NULL;
+
+	mempool_free(line_ws, pblk->line_ws_pool);
+}
+
+void pblk_line_mark_bb(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 nvm_tgt_dev *dev = pblk->dev;
+	struct ppa_addr *ppa = line_ws->priv;
+	int ret;
+
+	ret = nvm_set_tgt_bb_tbl(dev, ppa, 1, NVM_BLK_T_GRWN_BAD);
+	if (ret) {
+		struct pblk_line *line;
+		int pos;
+
+		line = &pblk->lines[pblk_ppa_to_line(*ppa)];
+		pos = pblk_ppa_to_pos(&dev->geo, *ppa);
+
+		pr_err("pblk: failed to mark bb, line:%d, pos:%d\n",
+				line->id, pos);
+	}
+
+	kfree(ppa);
+	mempool_free(line_ws, pblk->line_ws_pool);
+}
+
+void pblk_line_run_ws(struct pblk *pblk, void *priv,
+		      void (*work)(struct work_struct *))
+{
+	struct pblk_line_ws *line_ws;
+
+	line_ws = mempool_alloc(pblk->line_ws_pool, GFP_ATOMIC);
+	if (!line_ws)
+		return;
+
+	line_ws->pblk = pblk;
+	line_ws->priv = priv;
+
+	INIT_WORK(&line_ws->ws, work);
+	queue_work(pblk->kw_wq, &line_ws->ws);
+}
+
+void pblk_down_rq(struct pblk *pblk, struct ppa_addr *ppa_list, int nr_ppas,
+		  unsigned long *lun_bitmap)
+{
+	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 ret;
+
+	/*
+	 * Only send one inflight I/O per LUN. Since we map at a page
+	 * granurality, all ppas in the I/O will map to the same LUN
+	 */
+#ifdef CONFIG_NVM_DEBUG
+	int i;
+
+	for (i = 1; i < nr_ppas; i++)
+		BUG_ON(ppa_list[0].g.lun != ppa_list[i].g.lun ||
+				ppa_list[0].g.ch != ppa_list[i].g.ch);
+#endif
+	/* 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))
+		return;
+
+	rlun = &pblk->luns[lun_id];
+	ret = down_timeout(&rlun->wr_sem, msecs_to_jiffies(5000));
+	if (ret) {
+		switch (ret) {
+		case -ETIME:
+			pr_err("pblk: lun semaphore timed out\n");
+			break;
+		case -EINTR:
+			pr_err("pblk: lun semaphore timed out\n");
+			break;
+		}
+	}
+}
+
+void pblk_up_rq(struct pblk *pblk, struct ppa_addr *ppa_list, int nr_ppas,
+		unsigned long *lun_bitmap)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_lun *rlun;
+	int nr_luns = geo->nr_luns;
+	int bit = -1;
+
+	while ((bit = find_next_bit(lun_bitmap, nr_luns, bit + 1)) < nr_luns) {
+		rlun = &pblk->luns[bit];
+		up(&rlun->wr_sem);
+	}
+
+	kfree(lun_bitmap);
+}
+
+void pblk_update_map_cache(struct pblk *pblk, sector_t lba,
+			  struct ppa_addr ppa)
+{
+	struct ppa_addr *l2p_ppa;
+
+#ifdef CONFIG_NVM_DEBUG
+	BUG_ON(!nvm_addr_in_cache(ppa));
+	BUG_ON(pblk_rb_pos_oob(&pblk->rwb, nvm_addr_to_cacheline(ppa)));
+#endif
+
+	/* logic error: lba out-of-bounds */
+	BUG_ON(lba >= pblk->rl.nr_secs);
+
+	spin_lock(&pblk->trans_lock);
+	l2p_ppa = &pblk->trans_map[lba];
+
+	if (!nvm_addr_in_cache(*l2p_ppa) && !ppa_empty(*l2p_ppa))
+		pblk_page_invalidate(pblk, *l2p_ppa);
+
+	*l2p_ppa = ppa;
+	spin_unlock(&pblk->trans_lock);
+}
+
+void pblk_update_map_gc(struct pblk *pblk, sector_t lba, struct ppa_addr ppa,
+		       struct pblk_line *gc_line)
+{
+	struct ppa_addr *l2p_ppa;
+
+#ifdef CONFIG_NVM_DEBUG
+	BUG_ON(!nvm_addr_in_cache(ppa));
+	BUG_ON(pblk_rb_pos_oob(&pblk->rwb, nvm_addr_to_cacheline(ppa)));
+#endif
+
+	/* logic error: lba out-of-bounds */
+	WARN_ON(lba >= pblk->rl.nr_secs);
+
+	spin_lock(&pblk->trans_lock);
+	l2p_ppa = &pblk->trans_map[lba];
+
+	/* Prevent updated entries to be overwritten by GC */
+	if (nvm_addr_in_cache(*l2p_ppa) || ppa_empty(*l2p_ppa) ||
+				pblk_ppa_to_line(*l2p_ppa) != gc_line->id)
+		goto out;
+
+	*l2p_ppa = ppa;
+out:
+	spin_unlock(&pblk->trans_lock);
+}
+
+void pblk_update_map_dev(struct pblk *pblk, sector_t lba,
+			struct ppa_addr ppa, struct ppa_addr entry_line)
+{
+	struct ppa_addr *l2p_line;
+
+	/* logic error: lba out-of-bounds */
+	BUG_ON(lba >= pblk->rl.nr_secs);
+
+	spin_lock(&pblk->trans_lock);
+	l2p_line = &pblk->trans_map[lba];
+
+	/* Do not update L2P if the cacheline has been updated. In this case,
+	 * the mapped ppa must be einvalidated
+	 */
+	if (l2p_line->ppa != entry_line.ppa && !ppa_empty(ppa)) {
+		pblk_page_invalidate(pblk, ppa);
+		goto out;
+	}
+
+#ifdef CONFIG_NVM_DEBUG
+	BUG_ON(nvm_addr_in_cache(ppa));
+	BUG_ON(!nvm_addr_in_cache(*l2p_line) && !ppa_empty(*l2p_line));
+#endif
+
+	*l2p_line = ppa;
+out:
+	spin_unlock(&pblk->trans_lock);
+}
+
+void pblk_lookup_l2p_seq(struct pblk *pblk, struct ppa_addr *ppas,
+			 sector_t blba, int nr_secs)
+{
+	int i;
+
+	spin_lock(&pblk->trans_lock);
+	for (i = 0; i < nr_secs; i++)
+		ppas[i] = pblk->trans_map[blba + i];
+	spin_unlock(&pblk->trans_lock);
+}
+
+void pblk_lookup_l2p_rand(struct pblk *pblk, struct ppa_addr *ppas,
+			  u64 *lba_list, int nr_secs)
+{
+	sector_t lba;
+	int i;
+
+	spin_lock(&pblk->trans_lock);
+	for (i = 0; i < nr_secs; i++) {
+		lba = lba_list[i];
+		if (lba == ADDR_EMPTY) {
+			ppas[i].ppa = ADDR_EMPTY;
+		} else {
+			/* logic error: lba out-of-bounds */
+			BUG_ON(!(lba >= 0 && lba < pblk->rl.nr_secs));
+			ppas[i] = pblk->trans_map[lba];
+		}
+	}
+	spin_unlock(&pblk->trans_lock);
+}
diff --git a/drivers/lightnvm/pblk-gc.c b/drivers/lightnvm/pblk-gc.c
new file mode 100644
index 0000000..5ee0e38
--- /dev/null
+++ b/drivers/lightnvm/pblk-gc.c
@@ -0,0 +1,401 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@xxxxxxxxxxxx>
+ *                  Matias Bjorling <matias@xxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * pblk-gc.c - pblk's garbage collector
+ */
+
+#include "pblk.h"
+
+static int pblk_gc_move_valid_secs(struct pblk *pblk, struct pblk_line *line,
+				   u64 *lba_list, unsigned int secs_to_move)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	void *data;
+	unsigned int alloc_entries, nr_secs, secs_to_gc;
+	unsigned int secs_left = secs_to_move;
+	int off = 0, max = pblk->max_write_pgs;
+
+	if (!secs_to_move)
+		return 0;
+
+	alloc_entries = (secs_to_move > max) ? max : secs_to_move;
+
+	data = kmalloc(alloc_entries * geo->sec_size, GFP_KERNEL);
+	if (!data)
+		goto out;
+
+	do {
+		nr_secs = (secs_left > max) ? max : secs_left;
+
+		/* Read from GC victim block */
+		if (pblk_submit_read_gc(pblk, &lba_list[off], data, nr_secs,
+							&secs_to_gc, line))
+			goto fail_free_data;
+
+		if (!secs_to_gc)
+			goto next;
+
+		/* Write to buffer */
+		if (pblk_write_gc_to_cache(pblk, data, &lba_list[off],
+				nr_secs, secs_to_gc, line, PBLK_IOTYPE_GC))
+			goto fail_free_data;
+
+next:
+		secs_left -= nr_secs;
+		off += nr_secs;
+	} while (secs_left > 0);
+
+fail_free_data:
+	kfree(data);
+out:
+	return off;
+}
+
+static void pblk_put_line_back(struct pblk *pblk, struct pblk_line *line)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct list_head *move_list = NULL;
+
+	spin_lock(&line->lock);
+	WARN_ON(line->state != PBLK_LINESTATE_GC);
+	line->state = PBLK_LINESTATE_CLOSED;
+	move_list = pblk_line_gc_list(pblk, line);
+	spin_unlock(&line->lock);
+
+	if (move_list) {
+		spin_lock(&l_mg->gc_lock);
+		list_add_tail(&line->list, move_list);
+		spin_unlock(&l_mg->gc_lock);
+	}
+}
+
+static void pblk_gc_line_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 *line = line_ws->priv;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct line_emeta *emeta;
+	int max = pblk->max_write_pgs;
+	int sec_moved, sec_left;
+	u64 *gc_lba_list, *lba_list;
+	int nr_ppas, bit, ret;
+
+	pr_debug("pblk: line '%d' being reclaimed for GC\n", line->id);
+
+	spin_lock(&line->lock);
+	sec_left = line->vsc;
+	if (!sec_left) {
+		/* Lines are erased before being used (l_mg->data_/log_next) */
+		spin_unlock(&line->lock);
+		kref_put(&line->ref, pblk_line_put);
+		goto out;
+	}
+	spin_unlock(&line->lock);
+
+	/* logic error */
+	BUG_ON(sec_left < 0);
+
+	gc_lba_list = kmalloc_array(max, sizeof(u64), GFP_KERNEL);
+	if (!gc_lba_list)
+		goto out;
+
+	emeta = l_mg->gc_meta.meta;
+	if (!emeta) {
+		pr_err("pblk: cannot use GC emeta\n");
+		goto free_lba_list;
+	}
+
+	line->emeta = emeta;
+	ret = pblk_line_read_emeta(pblk, line);
+	if (ret) {
+		pr_err("pblk: line %d read emeta failed (%d)\n", line->id, ret);
+		goto 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, emeta);
+	if (!lba_list) {
+		pr_err("pblk: could not interpret emeta (line %d)\n", line->id);
+		goto put_line;
+	}
+
+	bit = -1;
+next_rq:
+	nr_ppas = 0;
+	do {
+		bit = find_next_zero_bit(line->invalid_bitmap, lm->sec_per_line,
+								bit + 1);
+		if (bit > line->emeta_ssec)
+			goto prepare_rq;
+
+		gc_lba_list[nr_ppas] = lba_list[bit];
+		nr_ppas++;
+	} while (nr_ppas < pblk->max_write_pgs);
+
+prepare_rq:
+	sec_moved = pblk_gc_move_valid_secs(pblk, line, gc_lba_list, nr_ppas);
+	if (sec_moved != nr_ppas) {
+		pr_err("pblk: could not GC all sectors: line:%d (%d/%d/%d)\n",
+						line->id, line->vsc,
+						sec_moved, nr_ppas);
+		pblk_put_line_back(pblk, line);
+		goto free_emeta;
+	}
+
+	sec_left -= sec_moved;
+	if (sec_left > 0)
+		goto next_rq;
+
+	/* Logic error */
+	BUG_ON(sec_left != 0);
+
+put_line:
+	/* Lines are erased before being used (l_mg->data_/log_next) */
+	kref_put(&line->ref, pblk_line_put);
+
+free_emeta:
+	line->emeta = NULL;
+free_lba_list:
+	kfree(gc_lba_list);
+out:
+	mempool_free(line_ws, pblk->line_ws_pool);
+}
+
+static int pblk_gc_line(struct pblk *pblk, struct pblk_line *line)
+{
+	struct pblk_line_ws *line_ws;
+
+	line_ws = mempool_alloc(pblk->line_ws_pool, GFP_ATOMIC);
+	if (!line_ws)
+		return 1;
+
+	line_ws->pblk = pblk;
+	line_ws->priv = line;
+
+	INIT_WORK(&line_ws->ws, pblk_gc_line_ws);
+	queue_work(pblk->gc_wq, &line_ws->ws);
+
+	return 0;
+}
+
+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 list_head *group_list;
+	int run_gc, gc_group = 0;
+
+	spin_lock(&l_mg->gc_lock);
+	list_for_each_entry_safe(line, tline, &l_mg->gc_full_list, list) {
+		spin_lock(&line->lock);
+		BUG_ON(line->state != PBLK_LINESTATE_CLOSED);
+		line->state = PBLK_LINESTATE_GC;
+		spin_unlock(&line->lock);
+
+		list_del(&line->list);
+		kref_put(&line->ref, pblk_line_put);
+	}
+
+	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);
+
+next_gc_group:
+	group_list = l_mg->gc_lists[gc_group++];
+	while (run_gc && !list_empty(group_list)) {
+		if (!run_gc)
+			goto out;
+
+		line = list_first_entry(group_list, struct pblk_line, list);
+		nr_blocks_free += line->blk_in_line;
+
+		spin_lock(&line->lock);
+		BUG_ON(line->state != PBLK_LINESTATE_CLOSED);
+		line->state = PBLK_LINESTATE_GC;
+		spin_unlock(&line->lock);
+
+		list_del(&line->list);
+		if (pblk_gc_line(pblk, line)) {
+			pr_err("pblk: failed to GC line %d\n", line->id);
+			goto out;
+		}
+
+		run_gc = (nr_blocks_need > nr_blocks_free || gc->gc_forced);
+	}
+
+	if (gc_group < PBLK_NR_GC_LISTS)
+		goto next_gc_group;
+
+out:
+	spin_unlock(&l_mg->gc_lock);
+}
+
+static void pblk_gc_kick(struct pblk *pblk)
+{
+	wake_up_process(pblk->ts_gc);
+	mod_timer(&pblk->gc_timer, jiffies + msecs_to_jiffies(GC_TIME_MSECS));
+}
+
+/*
+ * timed GC every interval.
+ */
+static void pblk_gc_timer(unsigned long data)
+{
+	struct pblk *pblk = (struct pblk *)data;
+
+	pblk_gc_kick(pblk);
+}
+
+static int pblk_gc_ts(void *data)
+{
+	struct pblk *pblk = data;
+
+	while (!kthread_should_stop()) {
+		pblk_gc_run(pblk);
+		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 running\n");
+}
+
+int pblk_gc_status(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;
+
+#ifdef CONFIG_NVM_DEBUG
+	lockdep_assert_held(&gc->lock);
+#endif
+
+	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);
+}
+
+/*
+ * If flush_wq == 1 then no lock should be held by the caller since
+ * flush_workqueue can sleep
+ */
+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 paused\n");
+}
+
+void pblk_gc_should_stop(struct pblk *pblk)
+{
+	struct pblk_gc *gc = &pblk->gc;
+
+	if (gc->gc_active && !gc->gc_forced)
+		pblk_gc_stop(pblk, 0);
+}
+
+void pblk_gc_sysfs_state_show(struct pblk *pblk, int *gc_enabled,
+			      int *gc_active)
+{
+	struct pblk_gc *gc = &pblk->gc;
+
+	spin_lock(&gc->lock);
+	*gc_enabled = gc->gc_enabled;
+	*gc_active = gc->gc_active;
+	spin_unlock(&gc->lock);
+}
+
+void pblk_gc_sysfs_force(struct pblk *pblk, int force)
+{
+	struct pblk_gc *gc = &pblk->gc;
+	int rsv = 0;
+
+	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);
+	spin_unlock(&gc->lock);
+}
+
+int pblk_gc_init(struct pblk *pblk)
+{
+	pblk->ts_gc = kthread_create(pblk_gc_ts, pblk, "pblk-gc");
+
+	setup_timer(&pblk->gc_timer, pblk_gc_timer, (unsigned long)pblk);
+	mod_timer(&pblk->gc_timer, jiffies + msecs_to_jiffies(GC_TIME_MSECS));
+
+	pblk->gc_wq = alloc_workqueue("pblk-gc", WQ_MEM_RECLAIM | WQ_UNBOUND,
+									1);
+	if (!pblk->gc_wq)
+		return -ENOMEM;
+
+	pblk->gc.gc_active = 0;
+	pblk->gc.gc_forced = 0;
+	pblk->gc.gc_enabled = 1;
+
+	spin_lock_init(&pblk->gc.lock);
+
+	return 0;
+}
+
+void pblk_gc_exit(struct pblk *pblk)
+{
+	del_timer(&pblk->gc_timer);
+	pblk_gc_stop(pblk, 1);
+
+	if (pblk->ts_gc)
+		kthread_stop(pblk->ts_gc);
+
+	if (pblk->gc_wq)
+		destroy_workqueue(pblk->gc_wq);
+}
diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
new file mode 100644
index 0000000..65f6beb
--- /dev/null
+++ b/drivers/lightnvm/pblk-init.c
@@ -0,0 +1,937 @@
+/*
+ * Copyright (C) 2015 IT University of Copenhagen (rrpc.c)
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@xxxxxxxxxxxx>
+ *                  Matias Bjorling <matias@xxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * Implementation of a physical block-device target for Open-channel SSDs.
+ *
+ * pblk-init.c - pblk's initialization. Derived from rrpc.c
+ */
+
+#include "pblk.h"
+
+static struct kmem_cache *pblk_blk_ws_cache, *pblk_rec_cache, *pblk_r_rq_cache,
+					*pblk_w_rq_cache, *pblk_line_meta_cache;
+static DECLARE_RWSEM(pblk_lock);
+
+static const struct block_device_operations pblk_fops = {
+	.owner		= THIS_MODULE,
+};
+
+static int pblk_rw_io(struct request_queue *q, struct pblk *pblk,
+			  struct bio *bio)
+{
+	int ret;
+
+	/* Read requests must be <= 256kb due to NVMe's 64 bit completion bitmap
+	 * constraint. Writes can be of arbitrary size.
+	 */
+	if (bio_data_dir(bio) == READ) {
+		blk_queue_split(q, &bio, q->bio_split);
+		ret = pblk_submit_read(pblk, bio);
+		if (ret == NVM_IO_DONE && bio_flagged(bio, BIO_CLONED))
+			bio_put(bio);
+
+		return ret;
+	}
+
+	/* Prevent deadlock in the case of a modest LUN configuration and large
+	 * user I/Os. Unless stalled, the rate limiter leaves at least 256KB
+	 * available for user I/O.
+	 */
+	if (unlikely(pblk_get_secs(bio) >= pblk_rl_sysfs_rate_show(&pblk->rl)))
+		blk_queue_split(q, &bio, q->bio_split);
+
+	return pblk_write_to_cache(pblk, bio, PBLK_IOTYPE_USER);
+}
+
+static blk_qc_t pblk_make_rq(struct request_queue *q, struct bio *bio)
+{
+	struct pblk *pblk = q->queuedata;
+
+	if (bio_op(bio) == REQ_OP_DISCARD) {
+		pblk_discard(pblk, bio);
+		if (!(bio->bi_opf & REQ_PREFLUSH)) {
+			bio_endio(bio);
+			return BLK_QC_T_NONE;
+		}
+	}
+
+	switch (pblk_rw_io(q, pblk, bio)) {
+	case NVM_IO_ERR:
+		bio_io_error(bio);
+		break;
+	case NVM_IO_DONE:
+		bio_endio(bio);
+		break;
+	}
+
+	return BLK_QC_T_NONE;
+}
+
+static void pblk_l2p_free(struct pblk *pblk)
+{
+	vfree(pblk->trans_map);
+}
+
+static int pblk_l2p_init(struct pblk *pblk)
+{
+	sector_t i;
+
+	pblk->trans_map = vmalloc(sizeof(struct ppa_addr) * pblk->rl.nr_secs);
+	if (!pblk->trans_map)
+		return -ENOMEM;
+
+	for (i = 0; i < pblk->rl.nr_secs; i++)
+		ppa_set_empty(&pblk->trans_map[i]);
+
+	return 0;
+}
+
+static void pblk_rwb_free(struct pblk *pblk)
+{
+	pblk_rb_data_free(&pblk->rwb);
+	vfree(pblk_rb_entries_ref(&pblk->rwb));
+	pblk_rl_free(&pblk->rl);
+}
+
+static int pblk_rwb_init(struct pblk *pblk)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_rb_entry *entries;
+	int pgs_in_rb;
+	unsigned long nr_entries;
+	unsigned int power_size, power_seg_sz;
+
+	pgs_in_rb = NVM_MEM_PAGE_WRITE * geo->sec_per_pg *
+				geo->nr_planes * geo->nr_luns;
+	nr_entries = pblk_rb_calculate_size(pblk->pgs_in_buffer);
+
+	entries = vzalloc(nr_entries * sizeof(struct pblk_rb_entry));
+	if (!entries)
+		return -ENOMEM;
+
+	power_size = get_count_order(nr_entries);
+	power_seg_sz = get_count_order(geo->sec_size);
+
+	return pblk_rb_init(&pblk->rwb, entries, power_size, power_seg_sz);
+}
+
+/* Minimum pages needed within a lun */
+#define PAGE_POOL_SIZE 16
+#define ADDR_POOL_SIZE 64
+
+static int pblk_set_ppaf(struct pblk *pblk)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct nvm_addr_format ppaf = geo->ppaf;
+	int power_len;
+
+	/* Re-calculate channel and lun format to adapt to configuration */
+	power_len = get_count_order(geo->nr_chnls);
+	if (1 << power_len != geo->nr_chnls) {
+		pr_err("pblk: supports only power-of-two channel config.\n");
+		return -EINVAL;
+	}
+	ppaf.ch_len = power_len;
+
+	power_len = get_count_order(geo->luns_per_chnl);
+	if (1 << power_len != geo->luns_per_chnl) {
+		pr_err("pblk: supports only power-of-two LUN config.\n");
+		return -EINVAL;
+	}
+	ppaf.lun_len = power_len;
+
+	pblk->ppaf.sec_offset = 0;
+	pblk->ppaf.pln_offset = ppaf.sect_len;
+	pblk->ppaf.ch_offset = pblk->ppaf.pln_offset + ppaf.pln_len;
+	pblk->ppaf.lun_offset = pblk->ppaf.ch_offset + ppaf.ch_len;
+	pblk->ppaf.pg_offset = pblk->ppaf.lun_offset + ppaf.lun_len;
+	pblk->ppaf.blk_offset = pblk->ppaf.pg_offset + ppaf.pg_len;
+	pblk->ppaf.sec_mask = (1ULL << ppaf.sect_len) - 1;
+	pblk->ppaf.pln_mask = ((1ULL << ppaf.pln_len) - 1) <<
+							pblk->ppaf.pln_offset;
+	pblk->ppaf.ch_mask = ((1ULL << ppaf.ch_len) - 1) <<
+							pblk->ppaf.ch_offset;
+	pblk->ppaf.lun_mask = ((1ULL << ppaf.lun_len) - 1) <<
+							pblk->ppaf.lun_offset;
+	pblk->ppaf.pg_mask = ((1ULL << ppaf.pg_len) - 1) <<
+							pblk->ppaf.pg_offset;
+	pblk->ppaf.blk_mask = ((1ULL << ppaf.blk_len) - 1) <<
+							pblk->ppaf.blk_offset;
+
+	return 0;
+}
+
+static int pblk_init_global_caches(struct pblk *pblk)
+{
+	down_write(&pblk_lock);
+	pblk_blk_ws_cache = kmem_cache_create("pblk_blk_ws",
+				sizeof(struct pblk_line_ws), 0, 0, NULL);
+	if (!pblk_blk_ws_cache) {
+		up_write(&pblk_lock);
+		return -ENOMEM;
+	}
+
+	pblk_rec_cache = kmem_cache_create("pblk_rec",
+				sizeof(struct pblk_rec_ctx), 0, 0, NULL);
+	if (!pblk_rec_cache) {
+		kmem_cache_destroy(pblk_blk_ws_cache);
+		up_write(&pblk_lock);
+		return -ENOMEM;
+	}
+
+	pblk_r_rq_cache = kmem_cache_create("pblk_r_rq", pblk_r_rq_size,
+				0, 0, NULL);
+	if (!pblk_r_rq_cache) {
+		kmem_cache_destroy(pblk_blk_ws_cache);
+		kmem_cache_destroy(pblk_rec_cache);
+		up_write(&pblk_lock);
+		return -ENOMEM;
+	}
+
+	pblk_w_rq_cache = kmem_cache_create("pblk_w_rq", pblk_w_rq_size,
+				0, 0, NULL);
+	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);
+		up_write(&pblk_lock);
+		return -ENOMEM;
+	}
+
+	pblk_line_meta_cache = kmem_cache_create("pblk_line_m",
+				pblk->lm.sec_bitmap_len, 0, 0, NULL);
+	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_w_rq_cache);
+		up_write(&pblk_lock);
+		return -ENOMEM;
+	}
+	up_write(&pblk_lock);
+
+	return 0;
+}
+
+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;
+
+	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;
+
+	pblk->page_pool = mempool_create_page_pool(PAGE_POOL_SIZE, 0);
+	if (!pblk->page_pool)
+		return -ENOMEM;
+
+	pblk->line_ws_pool = mempool_create_slab_pool(geo->nr_luns,
+							pblk_blk_ws_cache);
+	if (!pblk->line_ws_pool)
+		goto free_page_pool;
+
+	pblk->rec_pool = mempool_create_slab_pool(geo->nr_luns, pblk_rec_cache);
+	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)
+		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;
+
+	pblk->line_meta_pool =
+			mempool_create_slab_pool(16, pblk_line_meta_cache);
+	if (!pblk->line_meta_pool)
+		goto free_w_rq_pool;
+
+	pblk->kw_wq = alloc_workqueue("pblk-writer",
+					WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
+	if (!pblk->kw_wq)
+		goto free_line_meta_pool;
+
+	if (pblk_set_ppaf(pblk))
+		goto free_kw_wq;
+
+	if (pblk_rwb_init(pblk))
+		goto free_kw_wq;
+
+	INIT_LIST_HEAD(&pblk->compl_list);
+	return 0;
+
+free_kw_wq:
+	destroy_workqueue(pblk->kw_wq);
+free_line_meta_pool:
+	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_rec_pool:
+	mempool_destroy(pblk->rec_pool);
+free_blk_ws_pool:
+	mempool_destroy(pblk->line_ws_pool);
+free_page_pool:
+	mempool_destroy(pblk->page_pool);
+	return -ENOMEM;
+}
+
+static void pblk_core_free(struct pblk *pblk)
+{
+	if (pblk->kw_wq)
+		destroy_workqueue(pblk->kw_wq);
+
+	pblk_rwb_free(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->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_w_rq_cache);
+	kmem_cache_destroy(pblk_line_meta_cache);
+}
+
+static void pblk_luns_free(struct pblk *pblk)
+{
+	kfree(pblk->luns);
+}
+
+static void pblk_lines_free(struct pblk *pblk)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line *line;
+	int i;
+
+	spin_lock(&l_mg->free_lock);
+	for (i = 0; i < l_mg->nr_lines; i++) {
+		line = &pblk->lines[i];
+
+		pblk_line_free(pblk, line);
+		kfree(line->blk_bitmap);
+		kfree(line->erase_bitmap);
+	}
+	spin_unlock(&l_mg->free_lock);
+}
+
+static void pblk_line_meta_free(struct pblk *pblk)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	int i;
+
+	kfree(l_mg->bb_template);
+	kfree(l_mg->bb_aux);
+
+	pblk_mfree(l_mg->gc_meta.meta, l_mg->emeta_alloc_type);
+	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);
+	}
+
+	kfree(pblk->lines);
+}
+
+static int pblk_bb_discovery(struct nvm_tgt_dev *dev, struct pblk_lun *rlun)
+{
+	struct nvm_geo *geo = &dev->geo;
+	struct ppa_addr ppa;
+	u8 *blks;
+	int nr_blks, ret;
+
+	nr_blks = geo->blks_per_lun * geo->plane_mode;
+	blks = kmalloc(nr_blks, GFP_KERNEL);
+	if (!blks)
+		return -ENOMEM;
+
+	ppa.ppa = 0;
+	ppa.g.ch = rlun->bppa.g.ch;
+	ppa.g.lun = rlun->bppa.g.lun;
+
+	ret = nvm_get_tgt_bb_tbl(dev, ppa, blks);
+	if (ret)
+		goto out;
+
+	nr_blks = nvm_bb_tbl_fold(dev->parent, blks, nr_blks);
+	if (nr_blks < 0) {
+		kfree(blks);
+		ret = nr_blks;
+	}
+
+	rlun->bb_list = blks;
+
+out:
+	return ret;
+}
+
+static int pblk_bb_line(struct pblk *pblk, struct pblk_line *line)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	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++) {
+		rlun = &pblk->luns[i];
+		if (rlun->bb_list[line->id] == NVM_BLK_T_FREE)
+			continue;
+
+		set_bit(i, line->blk_bitmap);
+		bb_cnt++;
+	}
+
+	return bb_cnt;
+}
+
+static int pblk_luns_init(struct pblk *pblk, struct ppa_addr *luns)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_lun *rlun;
+	int i, ret;
+
+	/* TODO: Implement unbalanced LUN support */
+	if (geo->luns_per_chnl < 0) {
+		pr_err("pblk: unbalanced LUN config.\n");
+		return -EINVAL;
+	}
+
+	pblk->luns = kcalloc(geo->nr_luns, sizeof(struct pblk_lun), GFP_KERNEL);
+	if (!pblk->luns)
+		return -ENOMEM;
+
+	for (i = 0; i < geo->nr_luns; i++) {
+		/* Stripe across channels */
+		int ch = i % geo->nr_chnls;
+		int lun_raw = i / geo->nr_chnls;
+		int lunid = lun_raw + ch * geo->luns_per_chnl;
+
+		rlun = &pblk->luns[i];
+		rlun->bppa = luns[lunid];
+
+		sema_init(&rlun->wr_sem, 1);
+
+		ret = pblk_bb_discovery(dev, rlun);
+		if (ret) {
+			while (--i >= 0)
+				kfree(pblk->luns[i].bb_list);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int pblk_lines_configure(struct pblk *pblk)
+{
+	struct pblk_line *line;
+	int ret = 0;
+
+	/* Configure next line for user data */
+	line = pblk_line_get_first_data(pblk);
+	if (!line) {
+		pr_err("pblk: line list corrupted\n");
+		ret = -EFAULT;
+		goto out;
+	}
+
+	line = pblk_line_get_next_data(pblk);
+	if (!line) {
+		struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+
+		kref_put(&l_mg->data_line->ref, pblk_line_put);
+		pr_debug("pblk: starting instance with single data line\n");
+		goto out;
+	}
+
+out:
+	return ret;
+}
+
+/* See comment over struct line_emeta definition */
+static unsigned int calc_emeta_len(struct pblk *pblk, struct pblk_line_meta *lm)
+{
+	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);
+}
+
+/* TODO: Fit lba list in u32 when possible to use less pages */
+static int pblk_lines_init(struct pblk *pblk)
+{
+	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_line *line;
+	unsigned int smeta_len, emeta_len;
+	int bb_distance;
+	int nr_bad_blks;
+	int i;
+	int ret = 0;
+
+	lm->sec_per_line = geo->sec_per_blk * geo->nr_luns;
+	lm->blk_per_line = geo->nr_luns;
+	lm->blk_bitmap_len = BITS_TO_LONGS(geo->nr_luns) * sizeof(long);
+	lm->sec_bitmap_len = BITS_TO_LONGS(lm->sec_per_line) * sizeof(long);
+	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;
+
+	/* 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;
+	if (smeta_len > lm->smeta_len) {
+		i++;
+		goto add_smeta_page;
+	}
+
+	/* Calculate necessary pages for emeta. See comment over struct
+	 * line_emeta definition
+	 */
+	i = 1;
+add_emeta_page:
+	lm->emeta_sec = i * geo->sec_per_pl;
+	lm->emeta_len = lm->emeta_sec * geo->sec_size;
+
+	emeta_len = calc_emeta_len(pblk, lm);
+	if (emeta_len > lm->emeta_len) {
+		i++;
+		goto add_emeta_page;
+	}
+	lm->emeta_bb = geo->nr_luns - i;
+
+	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;
+				}
+		}
+
+		l_mg->gc_meta.meta = vmalloc(lm->emeta_len);
+		if (!l_mg->gc_meta.meta) {
+			for (i = 0; i < PBLK_DATA_LINES; i++) {
+				kfree(l_mg->sline_meta[i].meta);
+				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;
+				}
+		}
+
+		l_mg->gc_meta.meta = kmalloc(lm->emeta_len, GFP_KERNEL);
+		if (!l_mg->gc_meta.meta) {
+			for (i = 0; i < PBLK_DATA_LINES; i++) {
+				kfree(l_mg->sline_meta[i].meta);
+				kfree(l_mg->eline_meta[i].meta);
+				ret = -ENOMEM;
+				goto fail;
+			}
+		}
+	}
+
+	l_mg->bb_template = kzalloc(lm->sec_bitmap_len, GFP_KERNEL);
+	if (!l_mg->bb_template)
+		goto fail_free_meta;
+
+	l_mg->bb_aux = kzalloc(lm->sec_bitmap_len, GFP_KERNEL);
+	if (!l_mg->bb_aux)
+		goto fail_free_bb_template;
+
+	bb_distance = (geo->nr_luns) * geo->sec_per_pl;
+	for (i = 0; i < lm->sec_per_line; i += bb_distance)
+		bitmap_set(l_mg->bb_template, i, geo->sec_per_pl);
+
+	INIT_LIST_HEAD(&l_mg->free_list);
+	INIT_LIST_HEAD(&l_mg->corrupt_list);
+	INIT_LIST_HEAD(&l_mg->bad_list);
+	INIT_LIST_HEAD(&l_mg->gc_full_list);
+	INIT_LIST_HEAD(&l_mg->gc_high_list);
+	INIT_LIST_HEAD(&l_mg->gc_mid_list);
+	INIT_LIST_HEAD(&l_mg->gc_low_list);
+	INIT_LIST_HEAD(&l_mg->gc_empty_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->gc_lock);
+
+	pblk->rl.free_blocks = geo->blks_per_lun * geo->nr_luns;
+	pblk->capacity = geo->sec_per_lun * geo->nr_luns;
+	pblk->rl.total_blocks = pblk->rl.nr_secs = 0;
+
+	pblk->lines = kcalloc(l_mg->nr_lines, sizeof(struct pblk_line),
+								GFP_KERNEL);
+	if (!pblk->lines)
+		goto fail_free_bb_aux;
+
+	for (i = 0; i < l_mg->nr_lines; i++) {
+		line = &pblk->lines[i];
+
+		line->pblk = pblk;
+		line->id = i;
+		line->type = PBLK_LINETYPE_FREE;
+		line->state = PBLK_LINESTATE_FREE;
+		line->gc_group = PBLK_LINEGC_NONE;
+		spin_lock_init(&line->lock);
+
+		nr_bad_blks = pblk_bb_line(pblk, line);
+		if (nr_bad_blks < 0 || nr_bad_blks > lm->blk_per_line)
+			goto fail_free_lines;
+
+		pblk->rl.free_blocks -= nr_bad_blks;
+		pblk->capacity -= nr_bad_blks * geo->sec_per_blk;
+
+		line->blk_in_line = lm->blk_per_line - nr_bad_blks;
+		if (!line->blk_in_line) {
+			line->state = PBLK_LINESTATE_BAD;
+			continue;
+		}
+
+		pblk->rl.total_blocks += line->blk_in_line;
+		pblk->rl.nr_secs += (line->blk_in_line * geo->sec_per_blk);
+
+		l_mg->nr_free_lines++;
+		list_add_tail(&line->list, &l_mg->free_list);
+	}
+
+	/* 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);
+
+	return 0;
+fail_free_lines:
+	kfree(pblk->lines);
+fail_free_bb_aux:
+	kfree(l_mg->bb_aux);
+fail_free_bb_template:
+	kfree(l_mg->bb_template);
+fail_free_meta:
+	pblk_mfree(l_mg->gc_meta.meta, l_mg->emeta_alloc_type);
+	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);
+	}
+fail:
+	for (i = 0; i < geo->nr_luns; i++)
+		kfree(pblk->luns[i].bb_list);
+
+	return ret;
+}
+
+static int pblk_writer_init(struct pblk *pblk)
+{
+	setup_timer(&pblk->wtimer, pblk_write_timer_fn, (unsigned long)pblk);
+	mod_timer(&pblk->wtimer, jiffies + msecs_to_jiffies(100));
+
+	pblk->ts_writer = kthread_create(pblk_write_ts, pblk, "pblk-writer");
+
+	return 0;
+}
+
+static void pblk_writer_stop(struct pblk *pblk)
+{
+	if (pblk->ts_writer)
+		kthread_stop(pblk->ts_writer);
+	del_timer(&pblk->wtimer);
+}
+
+static void pblk_free(struct pblk *pblk)
+{
+	pblk_writer_stop(pblk);
+	pblk_luns_free(pblk);
+	pblk_lines_free(pblk);
+	pblk_line_meta_free(pblk);
+	pblk_core_free(pblk);
+	pblk_l2p_free(pblk);
+
+	kfree(pblk);
+}
+
+static void pblk_tear_down(struct pblk *pblk)
+{
+	pblk_flush_writer(pblk);
+	pblk_rb_sync_l2p(&pblk->rwb);
+
+	if (pblk_rb_tear_down_check(&pblk->rwb)) {
+		pr_err("pblk: write buffer error on tear down\n");
+		return;
+	}
+
+	pr_debug("pblk: consistent tear down\n");
+}
+
+static void pblk_exit(void *private)
+{
+	struct pblk *pblk = private;
+
+	down_write(&pblk_lock);
+	flush_workqueue(pblk->gc_wq);
+	pblk_tear_down(pblk);
+	pblk_gc_exit(pblk);
+	pblk_free(pblk);
+	up_write(&pblk_lock);
+}
+
+static sector_t pblk_capacity(void *private)
+{
+	struct pblk *pblk = private;
+	sector_t provisioned;
+
+	provisioned = pblk->capacity;
+	sector_div(provisioned, 10);
+	return provisioned * 9 * NR_PHY_IN_LOG;
+}
+
+static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk)
+{
+	struct nvm_geo *geo = &dev->geo;
+	struct request_queue *bqueue = dev->q;
+	struct request_queue *tqueue = tdisk->queue;
+	struct pblk *pblk;
+	int ret;
+
+	if (dev->identity.dom & NVM_RSP_L2P) {
+		pr_err("pblk: device-side L2P table not supported. (%x)\n",
+							dev->identity.dom);
+		return ERR_PTR(-EINVAL);
+	}
+
+	pblk = kzalloc(sizeof(struct pblk), GFP_KERNEL);
+	if (!pblk)
+		return ERR_PTR(-ENOMEM);
+
+	pblk->dev = dev;
+	pblk->disk = tdisk;
+
+	spin_lock_init(&pblk->trans_lock);
+	spin_lock_init(&pblk->lock);
+
+#ifdef CONFIG_NVM_DEBUG
+	atomic_set(&pblk->inflight_writes, 0);
+	atomic_set(&pblk->padded_writes, 0);
+	atomic_set(&pblk->nr_flush, 0);
+	atomic_set(&pblk->req_writes, 0);
+	atomic_set(&pblk->sub_writes, 0);
+	atomic_set(&pblk->sync_writes, 0);
+	atomic_set(&pblk->compl_writes, 0);
+	atomic_set(&pblk->inflight_meta, 0);
+	atomic_set(&pblk->compl_meta, 0);
+	atomic_set(&pblk->inflight_reads, 0);
+	atomic_set(&pblk->sync_reads, 0);
+	atomic_set(&pblk->recov_writes, 0);
+	atomic_set(&pblk->recov_gc_writes, 0);
+	atomic_set(&pblk->requeued_writes, 0);
+#endif
+
+	ret = pblk_luns_init(pblk, dev->luns);
+	if (ret) {
+		pr_err("pblk: could not initialize luns\n");
+		goto fail;
+	}
+
+	ret = pblk_lines_init(pblk);
+	if (ret) {
+		pr_err("pblk: could not initialize lines\n");
+		goto fail_free_luns;
+	}
+
+	ret = pblk_core_init(pblk);
+	if (ret) {
+		pr_err("pblk: could not initialize core\n");
+		goto fail_free_line_meta;
+	}
+
+	ret = pblk_lines_configure(pblk);
+	if (ret) {
+		pr_err("pblk: could not configure lines\n");
+		goto fail_free_core;
+	}
+
+	ret = pblk_l2p_init(pblk);
+	if (ret) {
+		pr_err("pblk: could not initialize maps\n");
+		goto fail_free_lines;
+	}
+
+	ret = pblk_writer_init(pblk);
+	if (ret) {
+		pr_err("pblk: could not initialize write thread\n");
+		goto fail_free_l2p;
+	}
+
+	ret = pblk_gc_init(pblk);
+	if (ret) {
+		pr_err("pblk: could not initialize gc\n");
+		goto fail_stop_writer;
+	}
+
+	/* inherit the size from the underlying device */
+	blk_queue_logical_block_size(tqueue, queue_physical_block_size(bqueue));
+	blk_queue_max_hw_sectors(tqueue, queue_max_hw_sectors(bqueue));
+
+	blk_queue_write_cache(tqueue, true, false);
+
+	tqueue->limits.discard_granularity = geo->pgs_per_blk * geo->pfpg_size;
+	tqueue->limits.discard_alignment = 0;
+	blk_queue_max_discard_sectors(tqueue, UINT_MAX >> 9);
+	tqueue->limits.discard_zeroes_data = 0;
+	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, tqueue);
+
+	pr_info("pblk init: luns:%u, lines:%d, secs:%llu, buf entries:%u\n",
+			geo->nr_luns, pblk->l_mg.nr_lines,
+			(unsigned long long)pblk->rl.nr_secs,
+			pblk->rwb.nr_entries);
+
+	wake_up_process(pblk->ts_writer);
+	return pblk;
+
+fail_stop_writer:
+	pblk_writer_stop(pblk);
+fail_free_l2p:
+	pblk_l2p_free(pblk);
+fail_free_lines:
+	pblk_lines_free(pblk);
+fail_free_core:
+	pblk_core_free(pblk);
+fail_free_line_meta:
+	pblk_line_meta_free(pblk);
+fail_free_luns:
+	pblk_luns_free(pblk);
+fail:
+	kfree(pblk);
+	return ERR_PTR(ret);
+}
+
+/* physical block device target */
+static struct nvm_tgt_type tt_pblk = {
+	.name		= "pblk",
+	.version	= {1, 0, 0},
+
+	.make_rq	= pblk_make_rq,
+	.capacity	= pblk_capacity,
+
+	.init		= pblk_init,
+	.exit		= pblk_exit,
+
+	.sysfs_init	= pblk_sysfs_init,
+	.sysfs_exit	= pblk_sysfs_exit,
+};
+
+static int __init pblk_module_init(void)
+{
+	return nvm_register_tgt_type(&tt_pblk);
+}
+
+static void pblk_module_exit(void)
+{
+	nvm_unregister_tgt_type(&tt_pblk);
+}
+
+module_init(pblk_module_init);
+module_exit(pblk_module_exit);
+MODULE_AUTHOR("Javier Gonzalez <javier@xxxxxxxxxxxx>");
+MODULE_AUTHOR("Matias Bjorling <matias@xxxxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Physical Block-Device for Open-Channel SSDs");
diff --git a/drivers/lightnvm/pblk-map.c b/drivers/lightnvm/pblk-map.c
new file mode 100644
index 0000000..aefe1cb
--- /dev/null
+++ b/drivers/lightnvm/pblk-map.c
@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@xxxxxxxxxxxx>
+ *                  Matias Bjorling <matias@xxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * pblk-map.c - pblk's lba-ppa mapping strategy
+ *
+ */
+
+#include "pblk.h"
+
+static void pblk_page_pad_invalidate(struct pblk *pblk, struct pblk_line *line,
+				     u64 paddr)
+{
+	spin_lock(&line->lock);
+	WARN_ON(test_and_set_bit(paddr, line->invalid_bitmap));
+	line->vsc--;
+	spin_unlock(&line->lock);
+
+	pblk_rb_sync_init(&pblk->rwb, NULL);
+	line->left_ssecs--;
+	if (!line->left_ssecs)
+		pblk_line_run_ws(pblk, line, pblk_line_close);
+	pblk_rb_sync_end(&pblk->rwb, NULL);
+}
+
+static void pblk_map_page_data(struct pblk *pblk, unsigned int sentry,
+			       struct ppa_addr *ppa_list,
+			       unsigned long *lun_bitmap,
+			       struct pblk_sec_meta *meta_list,
+			       unsigned int valid_secs)
+{
+	struct pblk_line *line = pblk_line_get_data(pblk);
+	struct line_emeta *emeta = line->emeta;
+	struct pblk_w_ctx *w_ctx;
+	u64 *lba_list = pblk_line_emeta_to_lbas(emeta);
+	u64 paddr;
+	int nr_secs = pblk->min_write_pgs;
+	int i;
+
+	paddr = pblk_alloc_page(pblk, line, nr_secs);
+
+	for (i = 0; i < nr_secs; i++, paddr++) {
+		/* ppa to be sent to the device */
+		ppa_list[i] = addr_to_gen_ppa(pblk, paddr, line->id);
+		kref_get(&line->ref);
+
+		/* Write context for target bio completion on write buffer. Note
+		 * that the write buffer is protected by the sync backpointer,
+		 * and a single writer thread have access to each specific entry
+		 * at a time. Thus, it is safe to modify the context for the
+		 * entry we are setting up for submission without taking any
+		 * lock or memory barrier.
+		 */
+		if (i < valid_secs) {
+			w_ctx = pblk_rb_w_ctx(&pblk->rwb, sentry + i);
+			w_ctx->paddr = paddr;
+			w_ctx->ppa = ppa_list[i];
+			meta_list[i].lba = w_ctx->lba;
+			lba_list[paddr] = w_ctx->lba;
+		} else {
+			meta_list[i].lba = ADDR_EMPTY;
+			lba_list[paddr] = ADDR_EMPTY;
+			pblk_page_pad_invalidate(pblk, line, paddr);
+		}
+	}
+
+	if (pblk_line_is_full(line)) {
+		line = pblk_line_replace_data(pblk);
+		if (!line)
+			return;
+	}
+
+	pblk_down_rq(pblk, ppa_list, nr_secs, lun_bitmap);
+}
+
+void pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
+		 unsigned long *lun_bitmap, unsigned int valid_secs,
+		 unsigned int off)
+{
+	struct pblk_sec_meta *meta_list = rqd->meta_list;
+	unsigned int map_secs;
+	int min = pblk->min_write_pgs;
+	int i;
+
+	for (i = off; i < rqd->nr_ppas; i += min) {
+		map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
+		pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
+					lun_bitmap, &meta_list[i], map_secs);
+	}
+}
+
+int pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
+		      unsigned int sentry, unsigned long *lun_bitmap,
+		      unsigned int valid_secs, struct ppa_addr *erase_ppa)
+{
+	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_sec_meta *meta_list = rqd->meta_list;
+	unsigned int map_secs;
+	int min = pblk->min_write_pgs;
+	int i, erase_lun;
+
+	for (i = 0; i < rqd->nr_ppas; i += min) {
+		map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
+		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;
+		if (!test_and_set_bit(erase_lun, e_line->erase_bitmap)) {
+			e_line->left_eblks--;
+			*erase_ppa = rqd->ppa_list[i];
+			erase_ppa->g.blk = e_line->id;
+
+			/* Avoid evaluating e_line->left_eblks */
+			pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
+							valid_secs, i + min);
+			return 0;
+		}
+	}
+
+	/* Erase blocks that are bad in this line but might not be in next */
+	if (unlikely(e_line->left_eblks) && ppa_empty(*erase_ppa)) {
+		struct pblk_line_meta *lm = &pblk->lm;
+
+		i = find_first_zero_bit(e_line->erase_bitmap, lm->blk_per_line);
+
+		set_bit(i, e_line->erase_bitmap);
+		e_line->left_eblks--;
+		*erase_ppa = pblk->luns[i].bppa; /* set ch and lun */
+		erase_ppa->g.blk = e_line->id;
+	}
+
+	return 0;
+}
diff --git a/drivers/lightnvm/pblk-rb.c b/drivers/lightnvm/pblk-rb.c
new file mode 100644
index 0000000..2fbf7cc
--- /dev/null
+++ b/drivers/lightnvm/pblk-rb.c
@@ -0,0 +1,857 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@xxxxxxxxxxxx>
+ *
+ * Based upon the circular ringbuffer.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
+ * USA.
+ *
+ * pblk-rb.c - pblk's write buffer
+ */
+
+#include <linux/circ_buf.h>
+
+#include "pblk.h"
+
+static DECLARE_RWSEM(pblk_rb_lock);
+
+void pblk_rb_data_free(struct pblk_rb *rb)
+{
+	struct pblk_rb_pages *p, *t;
+
+	down_write(&pblk_rb_lock);
+	list_for_each_entry_safe(p, t, &rb->pages, list) {
+		free_pages((unsigned long)page_address(p->pages), p->order);
+		list_del(&p->list);
+		kfree(p);
+	}
+	up_write(&pblk_rb_lock);
+}
+
+/*
+ * Initialize ring buffer. The data and metadata buffers must be previously
+ * allocated and their size must be a power of two
+ * (Documentation/circular-buffers.txt)
+ */
+int pblk_rb_init(struct pblk_rb *rb, struct pblk_rb_entry *rb_entry_base,
+		 unsigned int power_size, unsigned int power_seg_sz)
+{
+	struct pblk *pblk = container_of(rb, struct pblk, rwb);
+	unsigned int init_entry = 0;
+	unsigned int alloc_order = power_size;
+	unsigned int max_order = MAX_ORDER - 1;
+	unsigned int order, iter;
+
+	down_write(&pblk_rb_lock);
+	rb->entries = rb_entry_base;
+	rb->seg_size = (1 << power_seg_sz);
+	rb->nr_entries = (1 << power_size);
+	rb->mem = rb->subm = rb->sync = rb->l2p_update = 0;
+	rb->sync_point = EMPTY_ENTRY;
+
+	spin_lock_init(&rb->w_lock);
+	spin_lock_init(&rb->s_lock);
+
+	INIT_LIST_HEAD(&rb->pages);
+
+	if (alloc_order >= max_order) {
+		order = max_order;
+		iter = (1 << (alloc_order - max_order));
+	} else {
+		order = alloc_order;
+		iter = 1;
+	}
+
+	do {
+		struct pblk_rb_entry *entry;
+		struct pblk_rb_pages *page_set;
+		void *kaddr;
+		unsigned long set_size;
+		int i;
+
+		page_set = kmalloc(sizeof(struct pblk_rb_pages), GFP_KERNEL);
+		if (!page_set) {
+			up_write(&pblk_rb_lock);
+			return -ENOMEM;
+		}
+
+		page_set->order = order;
+		page_set->pages = alloc_pages(GFP_KERNEL, order);
+		if (!page_set->pages) {
+			kfree(page_set);
+			pblk_rb_data_free(rb);
+			up_write(&pblk_rb_lock);
+			return -ENOMEM;
+		}
+		kaddr = page_address(page_set->pages);
+
+		entry = &rb->entries[init_entry];
+		entry->data = kaddr;
+		entry->cacheline = pblk_cacheline_to_ppa(init_entry++);
+		entry->w_ctx.flags = PBLK_WRITABLE_ENTRY;
+
+		set_size = (1 << order);
+		for (i = 1; i < set_size; i++) {
+			entry = &rb->entries[init_entry];
+			entry->cacheline = pblk_cacheline_to_ppa(init_entry++);
+			entry->data = kaddr + (i * rb->seg_size);
+			entry->w_ctx.flags = PBLK_WRITABLE_ENTRY;
+			bio_list_init(&entry->w_ctx.bios);
+		}
+
+		list_add_tail(&page_set->list, &rb->pages);
+		iter--;
+	} while (iter > 0);
+	up_write(&pblk_rb_lock);
+
+#ifdef CONFIG_NVM_DEBUG
+	atomic_set(&rb->inflight_sync_point, 0);
+#endif
+
+	/*
+	 * Initialize rate-limiter, which controls access to the write buffer
+	 * but user and GC I/O
+	 */
+	pblk_rl_init(&pblk->rl, rb->nr_entries, &rb->w_lock);
+
+	return 0;
+}
+
+/*
+ * pblk_rb_calculate_size -- calculate the size of the write buffer
+ */
+unsigned int pblk_rb_calculate_size(unsigned int nr_entries)
+{
+	/* Alloc a write buffer that can at least fit 128 entries */
+	return (1 << max(get_count_order(nr_entries), 7));
+}
+
+void *pblk_rb_entries_ref(struct pblk_rb *rb)
+{
+	return rb->entries;
+}
+
+static void clean_wctx(struct pblk_w_ctx *w_ctx)
+{
+	int flags;
+
+try:
+	flags = READ_ONCE(w_ctx->flags);
+	if (!(flags & PBLK_SUBMITTED_ENTRY))
+		goto try;
+
+	/* Release flags on context. Protect from writes */
+	smp_store_release(&w_ctx->flags, PBLK_WRITABLE_ENTRY);
+	ppa_set_empty(&w_ctx->ppa);
+}
+
+#define pblk_rb_ring_count(head, tail, size) CIRC_CNT(head, tail, size)
+#define pblk_rb_ring_space(rb, head, tail, size) \
+					(CIRC_SPACE(head, tail, size))
+
+/*
+ * Buffer space is calculated with respect to the back pointer signaling
+ * synchronized entries to the media.
+ */
+unsigned int pblk_rb_space(struct pblk_rb *rb)
+{
+	unsigned int mem = READ_ONCE(rb->mem);
+	unsigned int sync = READ_ONCE(rb->sync);
+
+	return pblk_rb_ring_space(rb, mem, sync, rb->nr_entries);
+}
+
+/*
+ * Buffer count is calculated with respect to the submission entry signaling the
+ * entries that are available to send to the media
+ */
+unsigned int pblk_rb_read_count(struct pblk_rb *rb)
+{
+	unsigned int mem = READ_ONCE(rb->mem);
+	unsigned int subm = READ_ONCE(rb->subm);
+
+	return pblk_rb_ring_count(mem, subm, rb->nr_entries);
+}
+
+unsigned int pblk_rb_read_commit(struct pblk_rb *rb, unsigned int nr_entries)
+{
+	unsigned int subm;
+
+	subm = READ_ONCE(rb->subm);
+	/* Commit read means updating submission pointer */
+	smp_store_release(&rb->subm,
+				(subm + nr_entries) & (rb->nr_entries - 1));
+
+	return subm;
+}
+
+static int __pblk_rb_update_l2p(struct pblk_rb *rb, unsigned int *l2p_upd,
+				unsigned int to_update)
+{
+	struct pblk *pblk = container_of(rb, struct pblk, rwb);
+	struct pblk_line *line;
+	struct pblk_rb_entry *entry;
+	struct pblk_w_ctx *w_ctx;
+	unsigned int i;
+
+	for (i = 0; i < to_update; i++) {
+		entry = &rb->entries[*l2p_upd];
+		w_ctx = &entry->w_ctx;
+
+		line = &pblk->lines[pblk_ppa_to_line(w_ctx->ppa)];
+		pblk_update_map_dev(pblk, w_ctx->lba, w_ctx->ppa,
+							entry->cacheline);
+
+		kref_put(&line->ref, pblk_line_put);
+		clean_wctx(w_ctx);
+		*l2p_upd = (*l2p_upd + 1) & (rb->nr_entries - 1);
+	}
+
+	return 0;
+}
+
+/*
+ * When we move the l2p_update pointer, we update the l2p table - lookups will
+ * point to the physical address instead of to the cacheline in the write buffer
+ * from this moment on.
+ */
+static int pblk_rb_update_l2p(struct pblk_rb *rb, unsigned int nr_entries,
+			      unsigned int mem, unsigned int sync)
+{
+	unsigned int space, count;
+	int ret = 0;
+
+#ifdef CONFIG_NVM_DEBUG
+	lockdep_assert_held(&rb->w_lock);
+#endif
+
+	/* Update l2p only as buffer entries are being overwritten */
+	space = pblk_rb_ring_space(rb, mem, rb->l2p_update, rb->nr_entries);
+	if (space > nr_entries)
+		goto out;
+
+	count = nr_entries - space;
+	/* l2p_update used exclusively under rb->w_lock */
+	ret = __pblk_rb_update_l2p(rb, &rb->l2p_update, count);
+
+out:
+	return ret;
+}
+
+/*
+ * Update the l2p entry for all sectors stored on the write buffer. This means
+ * that all future lookups to the l2p table will point to a device address, not
+ * to the cacheline in the write buffer.
+ */
+void pblk_rb_sync_l2p(struct pblk_rb *rb)
+{
+	unsigned int sync;
+	unsigned int to_update;
+
+	spin_lock(&rb->w_lock);
+
+	/* Protect from reads and writes */
+	sync = smp_load_acquire(&rb->sync);
+
+	to_update = pblk_rb_ring_count(sync, rb->l2p_update, rb->nr_entries);
+	__pblk_rb_update_l2p(rb, &rb->l2p_update, to_update);
+
+	spin_unlock(&rb->w_lock);
+}
+
+/*
+ * Write @nr_entries to ring buffer from @data buffer if there is enough space.
+ * Typically, 4KB data chunks coming from a bio will be copied to the ring
+ * buffer, thus the write will fail if not all incoming data can be copied.
+ *
+ */
+struct ppa_addr pblk_rb_write_entry(struct pblk_rb *rb, void *data,
+				    struct pblk_w_ctx w_ctx,
+				    unsigned int ring_pos)
+{
+	struct pblk_rb_entry *entry;
+	int flags;
+
+	entry = &rb->entries[ring_pos];
+	flags = READ_ONCE(entry->w_ctx.flags);
+/* #ifdef CONFIG_NVM_DEBUG */
+	BUG_ON(!(flags & PBLK_WRITABLE_ENTRY));
+/* #endif */
+
+	memcpy(entry->data, data, rb->seg_size);
+
+	entry->w_ctx.lba = w_ctx.lba;
+	entry->w_ctx.ppa = w_ctx.ppa;
+	entry->w_ctx.paddr = w_ctx.paddr;
+
+	flags = w_ctx.flags | PBLK_WRITTEN_DATA;
+
+	/* Release flags on write context. Protect from writes */
+	smp_store_release(&entry->w_ctx.flags, flags);
+
+	return entry->cacheline;
+}
+
+static int pblk_rb_sync_point_set(struct pblk_rb *rb, struct bio *bio,
+				  unsigned int pos)
+{
+	struct pblk_rb_entry *entry;
+	unsigned int subm, sync_point;
+	int flags;
+
+	subm = READ_ONCE(rb->subm);
+
+#ifdef CONFIG_NVM_DEBUG
+	atomic_inc(&rb->inflight_sync_point);
+#endif
+
+	if (pos == subm)
+		return 0;
+
+	sync_point = (pos == 0) ? (rb->nr_entries - 1) : (pos - 1);
+	entry = &rb->entries[sync_point];
+
+	flags = READ_ONCE(entry->w_ctx.flags);
+	flags |= PBLK_FLUSH_ENTRY;
+
+	/* Release flags on context. Protect from writes */
+	smp_store_release(&entry->w_ctx.flags, flags);
+
+	/* Protect syncs */
+	smp_store_release(&rb->sync_point, sync_point);
+
+	spin_lock_irq(&rb->s_lock);
+	bio_list_add(&entry->w_ctx.bios, bio);
+	spin_unlock_irq(&rb->s_lock);
+
+	return 1;
+}
+
+static int __pblk_rb_may_write(struct pblk_rb *rb, unsigned int nr_entries,
+			     unsigned int *pos)
+{
+	unsigned int mem;
+	unsigned int sync;
+
+	sync = READ_ONCE(rb->sync);
+	mem = READ_ONCE(rb->mem);
+
+	if (pblk_rb_ring_space(rb, mem, sync, rb->nr_entries) < nr_entries)
+		return 0;
+
+	if (pblk_rb_update_l2p(rb, nr_entries, mem, sync))
+		return 0;
+
+	*pos = mem;
+
+	return 1;
+}
+
+static int pblk_rb_may_write(struct pblk_rb *rb, unsigned int nr_entries,
+			     unsigned int *pos)
+{
+	if (!__pblk_rb_may_write(rb, nr_entries, pos))
+		return 0;
+
+	/* Protect from read count */
+	smp_store_release(&rb->mem, (*pos + nr_entries) & (rb->nr_entries - 1));
+	return 1;
+}
+
+static int pblk_rb_may_write_flush(struct pblk_rb *rb, unsigned int nr_entries,
+				   unsigned int *pos, struct bio *bio,
+				   int *io_ret)
+{
+	unsigned int mem;
+
+	if (!__pblk_rb_may_write(rb, nr_entries, pos))
+		return 0;
+
+	mem = (*pos + nr_entries) & (rb->nr_entries - 1);
+	*io_ret = NVM_IO_DONE;
+
+	if (bio->bi_opf & REQ_PREFLUSH) {
+		struct pblk *pblk = container_of(rb, struct pblk, rwb);
+
+#ifdef CONFIG_NVM_DEBUG
+		atomic_inc(&pblk->nr_flush);
+#endif
+		if (pblk_rb_sync_point_set(&pblk->rwb, bio, mem))
+			*io_ret = NVM_IO_OK;
+	}
+
+	/* Protect from read count */
+	smp_store_release(&rb->mem, mem);
+	return 1;
+}
+
+/*
+ * Atomically check that (i) there is space on the write buffer for the
+ * incoming I/O, and (ii) the current I/O type has enough budget in the write
+ * buffer (rate-limiter).
+ */
+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;
+
+	spin_lock(&rb->w_lock);
+	if (!pblk_rl_user_may_insert(&pblk->rl, nr_entries)) {
+		spin_unlock(&rb->w_lock);
+		return NVM_IO_REQUEUE;
+	}
+
+	if (!pblk_rb_may_write_flush(rb, nr_entries, pos, bio, &flush_done)) {
+		spin_unlock(&rb->w_lock);
+		return NVM_IO_REQUEUE;
+	}
+
+	pblk_rl_user_in(&pblk->rl, nr_entries);
+	spin_unlock(&rb->w_lock);
+
+	return flush_done;
+}
+
+/*
+ * Look at pblk_rb_may_write_user comment
+ */
+int pblk_rb_may_write_gc(struct pblk_rb *rb, unsigned int nr_entries,
+			 unsigned int *pos)
+{
+	struct pblk *pblk = container_of(rb, struct pblk, rwb);
+
+	spin_lock(&rb->w_lock);
+	if (!pblk_rl_gc_may_insert(&pblk->rl, nr_entries)) {
+		spin_unlock(&rb->w_lock);
+		return 0;
+	}
+
+	if (!pblk_rb_may_write(rb, nr_entries, pos)) {
+		spin_unlock(&rb->w_lock);
+		return 0;
+	}
+
+	pblk_rl_gc_in(&pblk->rl, nr_entries);
+	spin_unlock(&rb->w_lock);
+
+	return 1;
+}
+
+/*
+ * The caller of this function must ensure that the backpointer will not
+ * overwrite the entries passed on the list.
+ */
+unsigned int pblk_rb_read_to_bio_list(struct pblk_rb *rb, struct bio *bio,
+				      struct list_head *list,
+				      unsigned int max)
+{
+	struct pblk_rb_entry *entry, *tentry;
+	struct page *page;
+	unsigned int read = 0;
+	int ret;
+
+	list_for_each_entry_safe(entry, tentry, list, index) {
+		if (read > max) {
+			pr_err("pblk: too many entries on list\n");
+			goto out;
+		}
+
+		page = virt_to_page(entry->data);
+		if (!page) {
+			pr_err("pblk: could not allocate write bio page\n");
+			goto out;
+		}
+
+		ret = bio_add_page(bio, page, rb->seg_size, 0);
+		if (ret != rb->seg_size) {
+			pr_err("pblk: could not add page to write bio\n");
+			goto out;
+		}
+
+		list_del(&entry->index);
+		read++;
+	}
+
+out:
+	return read;
+}
+
+/*
+ * Read available entries on rb and add them to the given bio. To avoid a memory
+ * copy, a page reference to the write buffer is used to be added to the 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)
+{
+	struct pblk *pblk = container_of(rb, struct pblk, rwb);
+	struct pblk_rb_entry *entry;
+	struct page *page;
+	unsigned int pad = 0, read = 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;
+		to_read = count;
+	}
+
+	c_ctx->sentry = pos;
+	c_ctx->nr_valid = to_read;
+	c_ctx->nr_padded = pad;
+
+	for (i = 0; i < to_read; i++) {
+		entry = &rb->entries[pos];
+
+		/* A write has been allowed into the buffer, but data is still
+		 * being copied to it. It is ok to busy wait.
+		 */
+try:
+		flags = READ_ONCE(entry->w_ctx.flags);
+		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");
+			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;
+		}
+
+		ret = bio_add_page(bio, page, rb->seg_size, 0);
+		if (ret != 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;
+		}
+
+		if (flags & PBLK_FLUSH_ENTRY) {
+			unsigned int sync_point;
+
+			sync_point = READ_ONCE(rb->sync_point);
+			if (sync_point == pos) {
+				/* Protect syncs */
+				smp_store_release(&rb->sync_point, EMPTY_ENTRY);
+			}
+
+			flags &= ~PBLK_FLUSH_ENTRY;
+#ifdef CONFIG_NVM_DEBUG
+			atomic_dec(&rb->inflight_sync_point);
+#endif
+		}
+
+		flags &= ~PBLK_WRITTEN_DATA;
+		flags |= PBLK_SUBMITTED_ENTRY;
+
+		/* Release flags on context. Protect from writes */
+		smp_store_release(&entry->w_ctx.flags, flags);
+
+		pos = (pos + 1) & (rb->nr_entries - 1);
+	}
+
+	read = to_read;
+	pblk_rl_out(&pblk->rl, user_io, gc_io);
+#ifdef CONFIG_NVM_DEBUG
+	atomic_add(pad, &((struct pblk *)
+			(container_of(rb, struct pblk, rwb)))->padded_writes);
+#endif
+out:
+	return read;
+}
+
+/*
+ * Copy to bio only if the lba matches the one on the given cache entry.
+ * Otherwise, it means that the entry has been overwritten, and the bio should
+ * be directed to disk.
+ */
+int pblk_rb_copy_to_bio(struct pblk_rb *rb, struct bio *bio, sector_t lba,
+			u64 pos, int bio_iter)
+{
+	struct pblk_rb_entry *entry;
+	struct pblk_w_ctx *w_ctx;
+	void *data;
+	int flags;
+	int ret = 1;
+
+	spin_lock(&rb->w_lock);
+
+#ifdef CONFIG_NVM_DEBUG
+	BUG_ON(pos >= rb->nr_entries);
+#endif
+	entry = &rb->entries[pos];
+	w_ctx = &entry->w_ctx;
+	flags = READ_ONCE(w_ctx->flags);
+
+	/* Check if the entry has been overwritten or is sheduled to be */
+	if (w_ctx->lba != lba || flags & PBLK_WRITABLE_ENTRY) {
+		ret = 0;
+		goto out;
+	}
+
+	/* Only advance the bio if it hasn't been advanced already. If advanced,
+	 * this bio is at least a partial bio (i.e., it has partially been
+	 * filled with data from the cache). If part of the data resides on the
+	 * media, we will read later on
+	 */
+	if (unlikely(!bio->bi_iter.bi_idx))
+		bio_advance(bio, bio_iter * PBLK_EXPOSED_PAGE_SIZE);
+
+	data = bio_data(bio);
+	memcpy(data, entry->data, rb->seg_size);
+
+out:
+	spin_unlock(&rb->w_lock);
+	return ret;
+}
+
+struct pblk_w_ctx *pblk_rb_w_ctx(struct pblk_rb *rb, unsigned int pos)
+{
+	unsigned int entry = pos & (rb->nr_entries - 1);
+
+	return &rb->entries[entry].w_ctx;
+}
+
+unsigned int pblk_rb_sync_init(struct pblk_rb *rb, unsigned long *flags)
+{
+	if (flags)
+		spin_lock_irqsave(&rb->s_lock, *flags);
+	else
+		spin_lock_irq(&rb->s_lock);
+
+	return rb->sync;
+}
+
+unsigned int pblk_rb_sync_advance(struct pblk_rb *rb, unsigned int nr_entries)
+{
+	struct pblk_rb_entry *entry;
+	struct pblk_w_ctx *w_ctx;
+	unsigned int sync;
+	unsigned int i;
+
+#ifdef CONFIG_NVM_DEBUG
+	lockdep_assert_held(&rb->s_lock);
+#endif
+
+	sync = READ_ONCE(rb->sync);
+
+	for (i = 0; i < nr_entries; i++) {
+		entry = &rb->entries[sync];
+		w_ctx = &entry->w_ctx;
+		sync = (sync + 1) & (rb->nr_entries - 1);
+	}
+
+	/* Protect from counts */
+	smp_store_release(&rb->sync, sync);
+
+	return sync;
+}
+
+void pblk_rb_sync_end(struct pblk_rb *rb, unsigned long *flags)
+{
+#ifdef CONFIG_NVM_DEBUG
+	lockdep_assert_held(&rb->s_lock);
+#endif
+
+	if (flags)
+		spin_unlock_irqrestore(&rb->s_lock, *flags);
+	else
+		spin_unlock_irq(&rb->s_lock);
+}
+
+unsigned int pblk_rb_sync_point_count(struct pblk_rb *rb)
+{
+	unsigned int subm, sync_point;
+	unsigned int count;
+
+	/* Protect syncs */
+	sync_point = smp_load_acquire(&rb->sync_point);
+	if (sync_point == EMPTY_ENTRY)
+		return 0;
+
+	subm = READ_ONCE(rb->subm);
+
+	/* The sync point itself counts as a sector to sync */
+	count = pblk_rb_ring_count(sync_point, subm, rb->nr_entries) + 1;
+
+	return count;
+}
+
+/*
+ * Scan from the current position of the sync pointer to find the entry that
+ * corresponds to the given ppa. This is necessary since write requests can be
+ * completed out of order. The assumption is that the ppa is close to the sync
+ * pointer thus the search will not take long.
+ *
+ * The caller of this function must guarantee that the sync pointer will no
+ * reach the entry while it is using the metadata associated with it. With this
+ * assumption in mind, there is no need to take the sync lock.
+ */
+struct pblk_rb_entry *pblk_rb_sync_scan_entry(struct pblk_rb *rb,
+					      struct ppa_addr *ppa)
+{
+	struct pblk_rb_entry *entry;
+	struct pblk_w_ctx *w_ctx;
+	unsigned int sync, subm, count;
+	unsigned int i;
+
+	sync = READ_ONCE(rb->sync);
+	subm = READ_ONCE(rb->subm);
+	count = pblk_rb_ring_count(subm, sync, rb->nr_entries);
+
+	for (i = 0; i < count; i++) {
+		entry = &rb->entries[sync];
+		w_ctx = &entry->w_ctx;
+
+		sync = (sync + 1) & (rb->nr_entries - 1);
+	}
+
+	return NULL;
+}
+
+int pblk_rb_tear_down_check(struct pblk_rb *rb)
+{
+	struct pblk_rb_entry *entry;
+	int i;
+	int ret = 0;
+
+	spin_lock(&rb->w_lock);
+	spin_lock_irq(&rb->s_lock);
+
+	if ((rb->mem == rb->subm) && (rb->subm == rb->sync) &&
+				(rb->sync == rb->l2p_update) &&
+				(rb->sync_point == EMPTY_ENTRY)) {
+		goto out;
+	}
+
+	if (rb->entries)
+		goto out;
+
+	for (i = 0; i < rb->nr_entries; i++) {
+		entry = &rb->entries[i];
+
+		if (entry->data)
+			goto out;
+	}
+
+	ret = 1;
+
+out:
+	spin_unlock(&rb->w_lock);
+	spin_unlock_irq(&rb->s_lock);
+
+	return ret;
+}
+
+unsigned int pblk_rb_wrap_pos(struct pblk_rb *rb, unsigned int pos)
+{
+	return (pos & (rb->nr_entries - 1));
+}
+
+int pblk_rb_pos_oob(struct pblk_rb *rb, u64 pos)
+{
+	return (pos >= rb->nr_entries);
+}
+
+ssize_t pblk_rb_sysfs(struct pblk_rb *rb, char *buf)
+{
+	struct pblk *pblk = container_of(rb, struct pblk, rwb);
+	struct pblk_c_ctx *c;
+	ssize_t offset;
+	int queued_entries = 0;
+
+	spin_lock_irq(&rb->s_lock);
+	list_for_each_entry(c, &pblk->compl_list, list)
+		queued_entries++;
+	spin_unlock_irq(&rb->s_lock);
+
+	if (rb->sync_point != ADDR_EMPTY)
+		offset = scnprintf(buf, PAGE_SIZE,
+			"%u\t%u\t%u\t%u\t%u\t%u\t%u - %u/%u/%u - %d\n",
+			rb->nr_entries,
+			rb->mem,
+			rb->subm,
+			rb->sync,
+			rb->l2p_update,
+#ifdef CONFIG_NVM_DEBUG
+			atomic_read(&rb->inflight_sync_point),
+#else
+			0,
+#endif
+			rb->sync_point,
+			pblk_rb_read_count(rb),
+			pblk_rb_space(rb),
+			pblk_rb_sync_point_count(rb),
+			queued_entries);
+	else
+		offset = scnprintf(buf, PAGE_SIZE,
+			"%u\t%u\t%u\t%u\t%u\t%u\tNULL - %u/%u/%u - %d\n",
+			rb->nr_entries,
+			rb->mem,
+			rb->subm,
+			rb->sync,
+			rb->l2p_update,
+#ifdef CONFIG_NVM_DEBUG
+			atomic_read(&rb->inflight_sync_point),
+#else
+			0,
+#endif
+			pblk_rb_read_count(rb),
+			pblk_rb_space(rb),
+			pblk_rb_sync_point_count(rb),
+			queued_entries);
+
+	return offset;
+}
+
+#ifdef CONFIG_NVM_DEBUG
+ssize_t pblk_rb_sysfs_vb(struct pblk_rb *rb, char *buf)
+{
+	struct pblk_rb_entry *entry;
+	struct pblk_w_ctx *w_ctx;
+	int flags;
+	int i;
+
+	for (i = 0; i < rb->nr_entries; i++) {
+		entry = &rb->entries[i];
+		w_ctx = &entry->w_ctx;
+		flags = READ_ONCE(w_ctx->flags);
+
+		pr_err("entry:%d - flags:%d\n", i, flags);
+	}
+
+	return 0;
+}
+#endif
diff --git a/drivers/lightnvm/pblk-read.c b/drivers/lightnvm/pblk-read.c
new file mode 100644
index 0000000..c468288
--- /dev/null
+++ b/drivers/lightnvm/pblk-read.c
@@ -0,0 +1,512 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@xxxxxxxxxxxx>
+ *                  Matias Bjorling <matias@xxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * pblk-read.c - pblk's read path
+ */
+
+#include "pblk.h"
+
+/*
+ * There is no guarantee that the value read from cache has not been updated and
+ * resides at another location in the cache. We guarantee though that if the
+ * value is read from the cache, it belongs to the mapped lba. In order to
+ * guarantee and order between writes and reads are ordered, a flush must be
+ * issued.
+ */
+static int pblk_read_from_cache(struct pblk *pblk, struct bio *bio,
+				sector_t lba, struct ppa_addr ppa,
+				int bio_iter)
+{
+	return pblk_rb_copy_to_bio(&pblk->rwb, bio, lba,
+				nvm_addr_to_cacheline(ppa), bio_iter);
+}
+
+static int pblk_read_ppalist_rq(struct pblk *pblk, struct nvm_rq *rqd,
+				unsigned long *read_bitmap)
+{
+	struct bio *bio = rqd->bio;
+	struct ppa_addr ppas[PBLK_MAX_REQ_ADDRS];
+	sector_t blba = pblk_get_lba(bio);
+	int nr_secs = rqd->nr_ppas;
+	int advanced_bio = 0;
+	int i, j = 0;
+
+	/* logic error: lba out-of-bounds */
+	BUG_ON(!(blba >= 0 && blba + nr_secs < pblk->rl.nr_secs));
+
+	pblk_lookup_l2p_seq(pblk, ppas, blba, nr_secs);
+
+	for (i = 0; i < nr_secs; i++) {
+		struct ppa_addr *p = &ppas[i];
+		sector_t lba = blba + i;
+
+retry:
+		if (ppa_empty(*p)) {
+			WARN_ON(test_and_set_bit(i, read_bitmap));
+			continue;
+		}
+
+		/* Try to read from write buffer. The address is later checked
+		 * on the write buffer to prevent retrieving overwritten data.
+		 */
+		if (nvm_addr_in_cache(*p)) {
+			if (!pblk_read_from_cache(pblk, bio, lba, *p, i)) {
+				pblk_lookup_l2p_seq(pblk, p, lba, 1);
+				goto retry;
+			}
+			WARN_ON(test_and_set_bit(i, read_bitmap));
+			advanced_bio = 1;
+		} else {
+			/* Read from media non-cached sectors */
+			rqd->ppa_list[j++] = *p;
+		}
+
+		if (advanced_bio)
+			bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
+	}
+
+#ifdef CONFIG_NVM_DEBUG
+	atomic_add(nr_secs, &pblk->inflight_reads);
+#endif
+
+	return NVM_IO_OK;
+}
+
+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;
+
+	return NVM_IO_OK;
+}
+
+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 bio *bio = rqd->bio;
+
+	if (rqd->error)
+		pblk_log_read_err(pblk, rqd);
+#ifdef CONFIG_NVM_DEBUG
+	else
+		BUG_ON(bio->bi_error);
+#endif
+
+	if (rqd->nr_ppas > 1)
+		nvm_dev_dma_free(dev->parent, rqd->ppa_list, rqd->dma_ppa_list);
+
+	bio_put(bio);
+	if (r_ctx->orig_bio) {
+#ifdef CONFIG_NVM_DEBUG
+		BUG_ON(r_ctx->orig_bio->bi_error);
+#endif
+		bio_endio(r_ctx->orig_bio);
+		bio_put(r_ctx->orig_bio);
+	}
+
+#ifdef CONFIG_NVM_DEBUG
+	atomic_add(rqd->nr_ppas, &pblk->sync_reads);
+	atomic_sub(rqd->nr_ppas, &pblk->inflight_reads);
+#endif
+
+	pblk_free_rqd(pblk, rqd, READ);
+}
+
+static int pblk_fill_partial_read_bio(struct pblk *pblk, struct nvm_rq *rqd,
+				      unsigned int bio_init_idx,
+				      unsigned long *read_bitmap)
+{
+	struct bio *new_bio, *bio = rqd->bio;
+	struct bio_vec src_bv, dst_bv;
+	void *ppa_ptr = NULL;
+	void *src_p, *dst_p;
+	dma_addr_t dma_ppa_list = 0;
+	int nr_secs = rqd->nr_ppas;
+	int nr_holes = nr_secs - bitmap_weight(read_bitmap, nr_secs);
+	int i, ret, hole;
+	DECLARE_COMPLETION_ONSTACK(wait);
+
+	new_bio = bio_alloc(GFP_KERNEL, nr_holes);
+	if (!new_bio) {
+		pr_err("pblk: could not alloc read bio\n");
+		return NVM_IO_ERR;
+	}
+
+	if (pblk_bio_add_pages(pblk, new_bio, GFP_KERNEL, nr_holes))
+		goto err;
+
+	if (nr_holes != new_bio->bi_vcnt) {
+		pr_err("pblk: malformed bio\n");
+		goto err;
+	}
+
+	new_bio->bi_iter.bi_sector = 0; /* artificial bio */
+	bio_set_op_attrs(new_bio, REQ_OP_READ, 0);
+	new_bio->bi_private = &wait;
+	new_bio->bi_end_io = pblk_end_bio_sync;
+
+	rqd->bio = new_bio;
+	rqd->nr_ppas = nr_holes;
+	rqd->end_io = NULL;
+
+	if (unlikely(nr_secs > 1 && nr_holes == 1)) {
+		ppa_ptr = rqd->ppa_list;
+		dma_ppa_list = rqd->dma_ppa_list;
+		rqd->ppa_addr = rqd->ppa_list[0];
+	}
+
+	ret = pblk_submit_read_io(pblk, rqd);
+	if (ret) {
+		bio_put(rqd->bio);
+		pr_err("pblk: read IO submission failed\n");
+		goto err;
+	}
+	wait_for_completion_io(&wait);
+
+	if (rqd->error) {
+		inc_stat(pblk, &pblk->read_failed, 0);
+#ifdef CONFIG_NVM_DEBUG
+		pblk_print_failed_rqd(pblk, rqd, rqd->error);
+#endif
+	}
+
+	if (unlikely(nr_secs > 1 && nr_holes == 1)) {
+		rqd->ppa_list = ppa_ptr;
+		rqd->dma_ppa_list = dma_ppa_list;
+	}
+
+	/* Fill the holes in the original bio */
+	i = 0;
+	hole = find_first_zero_bit(read_bitmap, nr_secs);
+	do {
+		src_bv = new_bio->bi_io_vec[i++];
+		dst_bv = bio->bi_io_vec[bio_init_idx + hole];
+
+		src_p = kmap_atomic(src_bv.bv_page);
+		dst_p = kmap_atomic(dst_bv.bv_page);
+
+		memcpy(dst_p + dst_bv.bv_offset,
+			src_p + src_bv.bv_offset,
+			PBLK_EXPOSED_PAGE_SIZE);
+
+		kunmap_atomic(src_p);
+		kunmap_atomic(dst_p);
+
+		mempool_free(src_bv.bv_page, pblk->page_pool);
+
+		hole = find_next_zero_bit(read_bitmap, nr_secs, hole + 1);
+	} while (hole < nr_secs);
+
+	bio_put(new_bio);
+
+	/* Complete the original bio and associated request */
+	rqd->bio = bio;
+	rqd->nr_ppas = nr_secs;
+	rqd->private = pblk;
+
+	bio_endio(bio);
+	pblk_end_io_read(rqd);
+	return NVM_IO_OK;
+
+err:
+	/* Free allocated pages in new bio */
+	pblk_bio_free_pages(pblk, bio, 0, new_bio->bi_vcnt);
+	rqd->private = pblk;
+	pblk_end_io_read(rqd);
+	return NVM_IO_ERR;
+}
+
+static int pblk_read_rq(struct pblk *pblk, struct nvm_rq *rqd,
+			unsigned long *read_bitmap)
+{
+	struct bio *bio = rqd->bio;
+	struct ppa_addr ppa;
+	sector_t lba = pblk_get_lba(bio);
+
+	/* logic error: lba out-of-bounds */
+	BUG_ON(!(lba >= 0 && lba < pblk->rl.nr_secs));
+
+	pblk_lookup_l2p_seq(pblk, &ppa, lba, 1);
+
+retry:
+	if (ppa_empty(ppa)) {
+		WARN_ON(test_and_set_bit(0, read_bitmap));
+		return NVM_IO_DONE;
+	}
+
+	/* Try to read from write buffer. The address is later checked on the
+	 * write buffer to prevent retrieving overwritten data.
+	 */
+	if (nvm_addr_in_cache(ppa)) {
+		if (!pblk_read_from_cache(pblk, bio, lba, ppa, 0)) {
+			pblk_lookup_l2p_seq(pblk, &ppa, lba, 1);
+			goto retry;
+		}
+		WARN_ON(test_and_set_bit(0, read_bitmap));
+	} else {
+		rqd->ppa_addr = ppa;
+	}
+
+#ifdef CONFIG_NVM_DEBUG
+	atomic_inc(&pblk->inflight_reads);
+#endif
+	return NVM_IO_OK;
+}
+
+int pblk_submit_read(struct pblk *pblk, struct bio *bio)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	int nr_secs = pblk_get_secs(bio);
+	struct nvm_rq *rqd;
+	unsigned long read_bitmap; /* Max 64 ppas per request */
+	unsigned int bio_init_idx;
+	int ret = NVM_IO_ERR;
+
+	if (nr_secs > PBLK_MAX_REQ_ADDRS)
+		return NVM_IO_ERR;
+
+	bitmap_zero(&read_bitmap, nr_secs);
+
+	rqd = pblk_alloc_rqd(pblk, READ);
+	if (IS_ERR(rqd)) {
+		pr_err_ratelimited("pblk: not able to alloc rqd");
+		bio_io_error(bio);
+		return NVM_IO_ERR;
+	}
+
+	rqd->opcode = NVM_OP_PREAD;
+	rqd->bio = bio;
+	rqd->nr_ppas = nr_secs;
+	rqd->private = pblk;
+	rqd->end_io = pblk_end_io_read;
+
+	/* Save the index for this bio's start. This is needed in case
+	 * we need to fill a partial read.
+	 */
+	bio_init_idx = pblk_get_bi_idx(bio);
+
+	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;
+		}
+
+		pblk_read_ppalist_rq(pblk, rqd, &read_bitmap);
+	} else
+		pblk_read_rq(pblk, rqd, &read_bitmap);
+
+	bio_get(bio);
+	if (bitmap_full(&read_bitmap, nr_secs)) {
+		bio_endio(bio);
+		pblk_end_io_read(rqd);
+		return NVM_IO_OK;
+	}
+
+	/* 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);
+
+		/* Clone read bio to deal with read errors internally */
+		int_bio = bio_clone_bioset(bio, GFP_KERNEL, fs_bio_set);
+		if (!int_bio) {
+			pr_err("pblk: could not clone read bio\n");
+			return NVM_IO_ERR;
+		}
+
+		rqd->bio = int_bio;
+		r_ctx->orig_bio = bio;
+
+		ret = pblk_submit_read_io(pblk, rqd);
+		if (ret) {
+			pr_err("pblk: read IO submission failed\n");
+			if (int_bio) {
+				bio_endio(bio);
+				bio_put(int_bio);
+			}
+			return ret;
+		}
+
+		return NVM_IO_OK;
+	}
+
+	/* The read bio request could be partially filled by the write buffer,
+	 * but there are some holes that need to be read from the drive.
+	 */
+	ret = pblk_fill_partial_read_bio(pblk, rqd, bio_init_idx, &read_bitmap);
+	if (ret) {
+		pr_err("pblk: failed to perform partial read\n");
+		return ret;
+	}
+
+	return NVM_IO_OK;
+
+fail_rqd_free:
+	pblk_free_rqd(pblk, rqd, READ);
+	return ret;
+}
+
+static int read_ppalist_rq_gc(struct pblk *pblk, struct nvm_rq *rqd,
+			      struct pblk_line *line, u64 *lba_list,
+			      unsigned int nr_secs)
+{
+	struct ppa_addr ppas[PBLK_MAX_REQ_ADDRS];
+	int valid_secs = 0;
+	int i;
+
+	pblk_lookup_l2p_rand(pblk, ppas, lba_list, nr_secs);
+
+	for (i = 0; i < nr_secs; i++) {
+		/* Ignore updated values until the moment */
+		if (nvm_addr_in_cache(ppas[i]) || ppas[i].g.blk != line->id ||
+							ppa_empty(ppas[i])) {
+			lba_list[i] = ADDR_EMPTY;
+			continue;
+		}
+
+		rqd->ppa_list[valid_secs++] = ppas[i];
+	}
+
+#ifdef CONFIG_NVM_DEBUG
+		atomic_add(valid_secs, &pblk->inflight_reads);
+#endif
+	return valid_secs;
+}
+
+static int read_rq_gc(struct pblk *pblk, struct nvm_rq *rqd,
+		      struct pblk_line *line, sector_t lba)
+{
+	struct ppa_addr ppa;
+	int valid_secs = 0;
+
+	if (lba == ADDR_EMPTY)
+		goto out;
+
+	/* logic error: lba out-of-bounds */
+	BUG_ON(!(lba >= 0 && lba < pblk->rl.nr_secs));
+
+	spin_lock(&pblk->trans_lock);
+	ppa = pblk->trans_map[lba];
+	spin_unlock(&pblk->trans_lock);
+
+	/* Ignore updated values until the moment */
+	if (nvm_addr_in_cache(ppa) || ppa.g.blk != line->id || ppa_empty(ppa))
+		goto out;
+
+	rqd->ppa_addr = ppa;
+	valid_secs = 1;
+
+#ifdef CONFIG_NVM_DEBUG
+	atomic_inc(&pblk->inflight_reads);
+#endif
+	return NVM_IO_OK;
+out:
+	return valid_secs;
+}
+
+int pblk_submit_read_gc(struct pblk *pblk, u64 *lba_list, void *data,
+			unsigned int nr_secs, unsigned int *secs_to_gc,
+			struct pblk_line *line)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct request_queue *q = dev->q;
+	struct bio *bio;
+	struct nvm_rq rqd;
+	int ret, data_len;
+	DECLARE_COMPLETION_ONSTACK(wait);
+
+	memset(&rqd, 0, sizeof(struct nvm_rq));
+
+	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;
+
+		*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;
+		}
+	} else {
+		*secs_to_gc = read_rq_gc(pblk, &rqd, line, lba_list[0]);
+	}
+
+	if (!(*secs_to_gc))
+		goto out;
+
+	data_len = (*secs_to_gc) * geo->sec_size;
+	bio = bio_map_kern(q, data, data_len, GFP_KERNEL);
+	if (!bio) {
+		pr_err("pblk: could not allocate GC bio\n");
+		goto err_free_dma;
+	}
+
+	bio->bi_iter.bi_sector = 0; /* artificial bio */
+	bio_set_op_attrs(bio, REQ_OP_READ, 0);
+	bio->bi_private = &wait;
+	bio->bi_end_io = pblk_end_bio_sync;
+
+	rqd.opcode = NVM_OP_PREAD;
+	rqd.nr_ppas = *secs_to_gc;
+	rqd.bio = bio;
+
+	ret = pblk_submit_read_io(pblk, &rqd);
+	if (ret) {
+		bio_endio(bio);
+		pr_err("pblk: GC read request failed\n");
+		goto err_free_bio;
+	}
+	wait_for_completion_io(&wait);
+
+	if (rqd.error) {
+		inc_stat(pblk, &pblk->read_failed_gc, 0);
+#ifdef CONFIG_NVM_DEBUG
+		pblk_print_failed_rqd(pblk, &rqd, rqd.error);
+#endif
+	}
+
+#ifdef CONFIG_NVM_DEBUG
+	atomic_add(*secs_to_gc, &pblk->sync_reads);
+	atomic_sub(*secs_to_gc, &pblk->inflight_reads);
+#endif
+
+	bio_put(bio);
+out:
+	if (rqd.nr_ppas > 1)
+		nvm_dev_dma_free(dev->parent, rqd.ppa_list, rqd.dma_ppa_list);
+	return NVM_IO_OK;
+
+err_free_bio:
+	bio_put(bio);
+err_free_dma:
+	if (rqd.nr_ppas > 1)
+		nvm_dev_dma_free(dev->parent, rqd.ppa_list, rqd.dma_ppa_list);
+	return NVM_IO_ERR;
+}
diff --git a/drivers/lightnvm/pblk-recovery.c b/drivers/lightnvm/pblk-recovery.c
new file mode 100644
index 0000000..c846a16
--- /dev/null
+++ b/drivers/lightnvm/pblk-recovery.c
@@ -0,0 +1,142 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial: Javier Gonzalez <javier@xxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * pblk-recovery.c - pblk's recovery path
+ */
+
+#include "pblk.h"
+
+/* pblk_submit_rec -- thread to submit recovery requests
+ *
+ * When a write request fails, rqd->ppa_status signals which specific ppas could
+ * not be written to the media. All ppas previous to the failed writes could be
+ * completed when the io finished, as part of the end_io recovery. However,
+ * successful writes after the failed ppas are not completed in order to
+ * maintain the consistency of the back pointer that guarantees sequentiality on
+ * the write buffer.
+ */
+void pblk_submit_rec(struct work_struct *work)
+{
+	struct pblk_rec_ctx *recovery =
+			container_of(work, struct pblk_rec_ctx, ws_rec);
+	struct pblk *pblk = recovery->pblk;
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_rq *rqd = recovery->rqd;
+	struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
+	int max_secs = nvm_max_phys_sects(dev);
+	struct bio *bio;
+	unsigned int nr_rec_secs;
+	unsigned int pgs_read;
+	int ret;
+
+	nr_rec_secs = bitmap_weight((unsigned long int *)&rqd->ppa_status,
+								max_secs);
+
+	bio = bio_alloc(GFP_KERNEL, nr_rec_secs);
+	if (!bio) {
+		pr_err("pblk: not able to create recovery bio\n");
+		return;
+	}
+
+	bio->bi_iter.bi_sector = 0;
+	bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+	rqd->bio = bio;
+	rqd->nr_ppas = nr_rec_secs;
+
+	pgs_read = pblk_rb_read_to_bio_list(&pblk->rwb, bio, &recovery->failed,
+								nr_rec_secs);
+	if (pgs_read != nr_rec_secs) {
+		pr_err("pblk: could not read recovery entries\n");
+		goto err;
+	}
+
+	if (pblk_setup_w_rec_rq(pblk, rqd, c_ctx)) {
+		pr_err("pblk: could not setup recovery request\n");
+		goto err;
+	}
+
+#ifdef CONFIG_NVM_DEBUG
+	atomic_add(nr_rec_secs, &pblk->recov_writes);
+#endif
+
+	ret = pblk_submit_io(pblk, rqd);
+	if (ret) {
+		pr_err("pblk: I/O submission failed: %d\n", ret);
+		goto err;
+	}
+
+	mempool_free(recovery, pblk->rec_pool);
+	return;
+err:
+	bio_put(bio);
+	pblk_free_rqd(pblk, rqd, WRITE);
+}
+
+int pblk_recov_setup_rq(struct pblk *pblk, struct pblk_c_ctx *c_ctx,
+			struct pblk_rec_ctx *recovery, u64 *comp_bits,
+			unsigned int comp)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	int max_secs = nvm_max_phys_sects(dev);
+	struct nvm_rq *rec_rqd;
+	struct pblk_c_ctx *rec_ctx;
+	int nr_entries = c_ctx->nr_valid + c_ctx->nr_padded;
+
+	rec_rqd = pblk_alloc_rqd(pblk, WRITE);
+	if (IS_ERR(rec_rqd)) {
+		pr_err("pblk: could not create recovery req.\n");
+		return -ENOMEM;
+	}
+
+	rec_ctx = nvm_rq_to_pdu(rec_rqd);
+
+	/* Copy completion bitmap, but exclude the first X completed entries */
+	bitmap_shift_right((unsigned long int *)&rec_rqd->ppa_status,
+				(unsigned long int *)comp_bits,
+				comp, max_secs);
+
+	/* Save the context for the entries that need to be re-written and
+	 * update current context with the completed entries.
+	 */
+	rec_ctx->sentry = pblk_rb_wrap_pos(&pblk->rwb, c_ctx->sentry + comp);
+	if (comp >= c_ctx->nr_valid) {
+		rec_ctx->nr_valid = 0;
+		rec_ctx->nr_padded = nr_entries - comp;
+
+		c_ctx->nr_padded = comp - c_ctx->nr_valid;
+	} else {
+		rec_ctx->nr_valid = c_ctx->nr_valid - comp;
+		rec_ctx->nr_padded = c_ctx->nr_padded;
+
+		c_ctx->nr_valid = comp;
+		c_ctx->nr_padded = 0;
+	}
+
+	recovery->rqd = rec_rqd;
+	recovery->pblk = pblk;
+
+	return 0;
+}
+
+u64 *pblk_recov_get_lba_list(struct pblk *pblk, struct line_emeta *emeta)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	u32 crc = ~(u32)0;
+
+	crc = crc32_le(crc, (unsigned char *)emeta + sizeof(crc),
+					lm->emeta_len - sizeof(crc));
+	if (emeta->crc != crc)
+		return NULL;
+
+	return pblk_line_emeta_to_lbas(emeta);
+}
diff --git a/drivers/lightnvm/pblk-rl.c b/drivers/lightnvm/pblk-rl.c
new file mode 100644
index 0000000..58d445d
--- /dev/null
+++ b/drivers/lightnvm/pblk-rl.c
@@ -0,0 +1,219 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@xxxxxxxxxxxx>
+ *                  Matias Bjorling <matias@xxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * pblk-rl.c - pblk's rate limiter for user I/O
+ *
+ */
+
+#include "pblk.h"
+
+static void pblk_rl_kick_u_timer(struct pblk_rl *rl)
+{
+	mod_timer(&rl->u_timer, jiffies + msecs_to_jiffies(5000));
+}
+
+int pblk_rl_user_may_insert(struct pblk_rl *rl, int nr_entries)
+{
+#ifdef CONFIG_NVM_DEBUG
+	lockdep_assert_held(rl->lock);
+#endif
+
+	return (!(rl->rb_user_cnt + nr_entries > rl->rb_user_max));
+}
+
+int pblk_rl_gc_may_insert(struct pblk_rl *rl, int nr_entries)
+{
+	int rb_user_active;
+
+#ifdef CONFIG_NVM_DEBUG
+	lockdep_assert_held(rl->lock);
+#endif
+
+	/* 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 (!(rl->rb_gc_cnt + nr_entries >
+					rl->rb_gc_max && rb_user_active));
+}
+
+void pblk_rl_user_in(struct pblk_rl *rl, int nr_entries)
+{
+#ifdef CONFIG_NVM_DEBUG
+	lockdep_assert_held(rl->lock);
+#endif
+
+	rl->rb_user_cnt += nr_entries;
+	/* Release user I/O state. Protect from GC */
+	smp_store_release(&rl->rb_user_active, 1);
+	pblk_rl_kick_u_timer(rl);
+}
+
+void pblk_rl_gc_in(struct pblk_rl *rl, int nr_entries)
+{
+#ifdef CONFIG_NVM_DEBUG
+	lockdep_assert_held(rl->lock);
+#endif
+
+	rl->rb_gc_cnt += nr_entries;
+}
+
+void pblk_rl_out(struct pblk_rl *rl, int nr_user, int nr_gc)
+{
+	spin_lock(rl->lock);
+	rl->rb_user_cnt -= nr_user;
+	rl->rb_gc_cnt -= nr_gc;
+	WARN_ON(rl->rb_user_cnt < 0 || rl->rb_gc_cnt < 0);
+	spin_unlock(rl->lock);
+}
+
+enum {
+	PBLK_RL_START_GC = 1,
+	PBLK_RL_STOP_GC = 2,
+};
+
+/*
+ * We check for (i) the number of free blocks in the current LUN and (ii) the
+ * total number of free blocks in the pblk instance. This is to even out the
+ * number of free blocks on each LUN when GC kicks in.
+ *
+ * Only the total number of free blocks is used to configure the rate limiter.
+ */
+static int pblk_rl_update_rates(struct pblk_rl *rl, unsigned long max)
+{
+	unsigned int high = 1 << rl->high_pw;
+	unsigned int low = 1 << rl->low_pw;
+	int ret;
+
+#ifdef CONFIG_NVM_DEBUG
+	lockdep_assert_held(rl->lock);
+#endif
+
+	if (rl->free_blocks >= high) {
+		rl->rb_user_max = max - rl->rb_gc_rsv;
+		rl->rb_gc_max = rl->rb_gc_rsv;
+		ret = PBLK_RL_STOP_GC;
+	} else if (rl->free_blocks > low && rl->free_blocks < high) {
+		int shift = rl->high_pw - rl->rb_windows_pw;
+		int user_windows = rl->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);
+		ret = PBLK_RL_START_GC;
+	} else {
+		rl->rb_user_max = 0;
+		rl->rb_gc_max = max;
+		ret = PBLK_RL_START_GC;
+	}
+
+	return ret;
+}
+
+void pblk_rl_set_gc_rsc(struct pblk_rl *rl, int rsv)
+{
+	spin_lock(rl->lock);
+	rl->rb_gc_rsv = rl->rb_gc_max = rsv;
+	spin_unlock(rl->lock);
+}
+
+void pblk_rl_free_lines_inc(struct pblk_rl *rl, struct pblk_line *line)
+{
+	struct pblk *pblk = container_of(rl, struct pblk, rl);
+	int ret;
+
+	spin_lock(rl->lock);
+	rl->free_blocks += line->blk_in_line;
+	ret = pblk_rl_update_rates(rl, rl->rb_budget);
+	spin_unlock(rl->lock);
+
+	if (ret == PBLK_RL_START_GC)
+		pblk_gc_should_start(pblk);
+	else
+		pblk_gc_should_stop(pblk);
+}
+
+void pblk_rl_free_lines_dec(struct pblk_rl *rl, struct pblk_line *line)
+{
+	struct pblk *pblk = container_of(rl, struct pblk, rl);
+	int ret;
+
+	spin_lock(rl->lock);
+	rl->free_blocks -= line->blk_in_line;
+	ret = pblk_rl_update_rates(rl, rl->rb_budget);
+	spin_unlock(rl->lock);
+
+	if (ret == PBLK_RL_START_GC)
+		pblk_gc_should_start(pblk);
+	else
+		pblk_gc_should_stop(pblk);
+}
+
+unsigned long pblk_rl_nr_free_blks(struct pblk_rl *rl)
+{
+	unsigned long nr_free_blocks;
+
+	spin_lock(rl->lock);
+	nr_free_blocks = rl->free_blocks;
+	spin_unlock(rl->lock);
+
+	return nr_free_blocks;
+}
+
+int pblk_rl_gc_thrs(struct pblk_rl *rl)
+{
+	return (1 << rl->high_pw) + 1;
+}
+
+int pblk_rl_sysfs_rate_show(struct pblk_rl *rl)
+{
+	return rl->rb_user_max;
+}
+
+static void pblk_rl_u_timer(unsigned long data)
+{
+	struct pblk_rl *rl = (struct pblk_rl *)data;
+
+	/* Release user I/O state. Protect from GC */
+	smp_store_release(&rl->rb_user_active, 0);
+}
+
+void pblk_rl_free(struct pblk_rl *rl)
+{
+	del_timer(&rl->u_timer);
+}
+
+void pblk_rl_init(struct pblk_rl *rl, int budget, spinlock_t *lock)
+{
+	unsigned int rb_windows;
+
+	rl->high_pw = get_count_order(rl->total_blocks / PBLK_USER_HIGH_THRS);
+	rl->low_pw = get_count_order(rl->total_blocks / PBLK_USER_LOW_THRS);
+
+	/* This will always be a power-of-2 */
+	rb_windows = budget / PBLK_MAX_REQ_ADDRS;
+	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;
+	rl->rb_user_max = budget;
+	rl->rb_user_cnt = 0;
+	rl->rb_gc_max = 0;
+	rl->rb_gc_cnt = 0;
+
+	setup_timer(&rl->u_timer, pblk_rl_u_timer, (unsigned long)rl);
+	rl->rb_user_active = 0;
+
+	rl->lock = lock;
+}
diff --git a/drivers/lightnvm/pblk-sysfs.c b/drivers/lightnvm/pblk-sysfs.c
new file mode 100644
index 0000000..546b493
--- /dev/null
+++ b/drivers/lightnvm/pblk-sysfs.c
@@ -0,0 +1,947 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@xxxxxxxxxxxx>
+ *                  Matias Bjorling <matias@xxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * Implementation of a physical block-device target for Open-channel SSDs.
+ *
+ * pblk-sysfs.c - pblk's sysfs
+ *
+ */
+
+#include "pblk.h"
+
+static ssize_t pblk_sysfs_luns_show(struct pblk *pblk, char *page)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_lun *rlun;
+	ssize_t sz = 0;
+	int i;
+
+	for (i = 0; i < geo->nr_luns; i++) {
+		int active = 1;
+
+		rlun = &pblk->luns[i];
+		if (!down_trylock(&rlun->wr_sem)) {
+			active = 0;
+			up(&rlun->wr_sem);
+		}
+		sz += sprintf(page + sz, "pblk: pos:%d, ch:%d, lun:%d - %d\n",
+					i,
+					rlun->bppa.g.ch,
+					rlun->bppa.g.lun,
+					active);
+	}
+
+	return sz;
+}
+
+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;
+	unsigned long free_blocks, total_blocks;
+	int rb_user_max, rb_user_cnt;
+	int rb_gc_max, rb_gc_rsv, rb_gc_cnt, rb_budget;
+
+	spin_lock(pblk->rl.lock);
+	free_blocks = pblk->rl.free_blocks;
+	rb_user_max = pblk->rl.rb_user_max;
+	rb_user_cnt = pblk->rl.rb_user_cnt;
+	rb_gc_max = pblk->rl.rb_gc_max;
+	rb_gc_rsv = pblk->rl.rb_gc_rsv;
+	rb_gc_cnt = pblk->rl.rb_gc_cnt;
+	rb_budget = pblk->rl.rb_budget;
+	spin_unlock(pblk->rl.lock);
+
+	total_blocks = geo->blks_per_lun * geo->nr_luns;
+
+	return sprintf(page,
+		"u:%u/%u,gc:%u/%u/%u(%u)(stop:<%u,full:>%u,free:%lu/%lu)\n",
+				rb_user_cnt,
+				rb_user_max,
+				rb_gc_cnt,
+				rb_gc_max,
+				rb_gc_rsv,
+				rb_budget,
+				1 << pblk->rl.low_pw,
+				1 << pblk->rl.high_pw,
+				free_blocks,
+				total_blocks);
+}
+
+static ssize_t pblk_sysfs_gc_state_show(struct pblk *pblk, char *page)
+{
+	int gc_enabled, gc_active;
+
+	pblk_gc_sysfs_state_show(pblk, &gc_enabled, &gc_active);
+	return sprintf(page, "gc_enabled=%d, gc_active=%d\n",
+					gc_enabled, gc_active);
+}
+
+static ssize_t pblk_sysfs_stats(struct pblk *pblk, char *page)
+{
+	ssize_t offset;
+
+	spin_lock_irq(&pblk->lock);
+	offset = sprintf(page, "read_failed=%lu, read_high_ecc=%lu, read_empty=%lu, read_failed_gc=%lu, write_failed=%lu, erase_failed=%lu\n",
+			pblk->read_failed, pblk->read_high_ecc,
+			pblk->read_empty, pblk->read_failed_gc,
+			pblk->write_failed, pblk->erase_failed);
+	spin_unlock_irq(&pblk->lock);
+
+	return offset;
+}
+
+static ssize_t pblk_sysfs_write_buffer(struct pblk *pblk, char *page)
+{
+	return pblk_rb_sysfs(&pblk->rwb, page);
+}
+
+static ssize_t pblk_sysfs_ppaf(struct pblk *pblk, char *page)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	ssize_t sz = 0;
+
+	sz = sprintf(page,
+		"g:blk:%d/%d,pg:%d/%d,lun:%d/%d,ch:%d/%d,pl:%d/%d,sec:%d/%d\n",
+		pblk->ppaf.blk_offset, geo->ppaf.blk_len,
+		pblk->ppaf.pg_offset, geo->ppaf.pg_len,
+		pblk->ppaf.lun_offset, geo->ppaf.lun_len,
+		pblk->ppaf.ch_offset, geo->ppaf.ch_len,
+		pblk->ppaf.pln_offset, geo->ppaf.pln_len,
+		pblk->ppaf.sec_offset, geo->ppaf.sect_len);
+
+	sz += sprintf(page + sz,
+		"d:blk:%d/%d,pg:%d/%d,lun:%d/%d,ch:%d/%d,pl:%d/%d,sec:%d/%d\n",
+		geo->ppaf.blk_offset, geo->ppaf.blk_len,
+		geo->ppaf.pg_offset, geo->ppaf.pg_len,
+		geo->ppaf.lun_offset, geo->ppaf.lun_len,
+		geo->ppaf.ch_offset, geo->ppaf.ch_len,
+		geo->ppaf.pln_offset, geo->ppaf.pln_len,
+		geo->ppaf.sect_offset, geo->ppaf.sect_len);
+
+	return sz;
+}
+
+static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page)
+{
+	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 pblk_line *line;
+	ssize_t sz = 0;
+	int nr_free_lines;
+	int cur_data, cur_log;
+	int free_line_cnt = 0, closed_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 msecs, ssecs, cur_sec, vsc, sec_in_line, map_weight, meta_weight;
+
+	spin_lock(&l_mg->free_lock);
+	cur_data = (l_mg->data_line) ? l_mg->data_line->id : -1;
+	cur_log = (l_mg->log_line) ? l_mg->log_line->id : -1;
+	nr_free_lines = l_mg->nr_free_lines;
+
+	list_for_each_entry(line, &l_mg->free_list, list)
+		free_line_cnt++;
+	spin_unlock(&l_mg->free_lock);
+
+	spin_lock(&l_mg->gc_lock);
+	list_for_each_entry(line, &l_mg->gc_full_list, list) {
+		if (line->type == PBLK_LINETYPE_DATA)
+			d_line_cnt++;
+		else if (line->type == PBLK_LINETYPE_LOG)
+			l_line_cnt++;
+		closed_line_cnt++;
+		gc_full++;
+	}
+
+	list_for_each_entry(line, &l_mg->gc_high_list, list) {
+		if (line->type == PBLK_LINETYPE_DATA)
+			d_line_cnt++;
+		else if (line->type == PBLK_LINETYPE_LOG)
+			l_line_cnt++;
+		closed_line_cnt++;
+		gc_high++;
+	}
+
+	list_for_each_entry(line, &l_mg->gc_mid_list, list) {
+		if (line->type == PBLK_LINETYPE_DATA)
+			d_line_cnt++;
+		else if (line->type == PBLK_LINETYPE_LOG)
+			l_line_cnt++;
+		closed_line_cnt++;
+		gc_mid++;
+	}
+
+	list_for_each_entry(line, &l_mg->gc_low_list, list) {
+		if (line->type == PBLK_LINETYPE_DATA)
+			d_line_cnt++;
+		else if (line->type == PBLK_LINETYPE_LOG)
+			l_line_cnt++;
+		closed_line_cnt++;
+		gc_low++;
+	}
+
+	list_for_each_entry(line, &l_mg->gc_empty_list, list) {
+		if (line->type == PBLK_LINETYPE_DATA)
+			d_line_cnt++;
+		else if (line->type == PBLK_LINETYPE_LOG)
+			l_line_cnt++;
+		closed_line_cnt++;
+		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)
+		cor++;
+
+	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;
+	sec_in_line = l_mg->data_line->sec_in_line;
+	meta_weight = bitmap_weight(&l_mg->meta_bitmap, PBLK_DATA_LINES);
+	map_weight = bitmap_weight(l_mg->data_line->map_bitmap,
+							lm->sec_per_line);
+	spin_unlock(&l_mg->gc_lock);
+
+	if (nr_free_lines != free_line_cnt)
+		pr_err("pblk: corrupted free line list\n");
+
+	sz = sprintf(page,
+		"line: nluns:%d, nblks:%d, nsecs:%d\n",
+		geo->nr_luns, lm->blk_per_line, lm->sec_per_line);
+
+	sz += sprintf(page + sz,
+		"lines:d:%d,l:%d-f:%d(%d),b:%d,co:%d,c:%d(d:%d,l:%d)t:%d\n",
+		cur_data, cur_log,
+		free, nr_free_lines, bad, cor,
+		closed_line_cnt,
+		d_line_cnt, l_line_cnt,
+		l_mg->nr_lines);
+
+	sz += sprintf(page + sz,
+		"lines GC: full:%d, high:%d, mid:%d, low:%d, empty:%d\n",
+		gc_full, gc_high, gc_mid, gc_low, gc_empty);
+
+	sz += sprintf(page + 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,
+		map_weight, lm->sec_per_line, meta_weight);
+
+	return sz;
+}
+
+static ssize_t pblk_sysfs_lines_info(struct pblk *pblk, char *page)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_line_meta *lm = &pblk->lm;
+	ssize_t sz = 0;
+
+	sz = sprintf(page, "smeta - len:%d, secs:%d\n",
+					lm->smeta_len, lm->smeta_sec);
+	sz += sprintf(page + sz, "emeta - len:%d, sec:%d, bb_start:%d\n",
+					lm->emeta_len, lm->emeta_sec,
+					lm->emeta_bb);
+	sz += sprintf(page + sz, "bitmap lengths: sec:%d, blk:%d, lun:%d\n",
+					lm->sec_bitmap_len,
+					lm->blk_bitmap_len,
+					lm->lun_bitmap_len);
+	sz += sprintf(page + sz, "blk_line:%d, sec_line:%d, sec_blk:%d\n",
+					lm->blk_per_line,
+					lm->sec_per_line,
+					geo->sec_per_blk);
+
+	return sz;
+}
+
+#ifdef CONFIG_NVM_DEBUG
+static ssize_t pblk_sysfs_stats_debug(struct pblk *pblk, char *page)
+{
+	return sprintf(page, "%u\t%u\t%u\t%u\t%u\t%u\t%u\t%u\t%u\t%u\t%u\t%u\t%u\t%u\n",
+			atomic_read(&pblk->inflight_writes),
+			atomic_read(&pblk->inflight_reads),
+			atomic_read(&pblk->req_writes),
+			atomic_read(&pblk->nr_flush),
+			atomic_read(&pblk->padded_writes),
+			atomic_read(&pblk->sub_writes),
+			atomic_read(&pblk->sync_writes),
+			atomic_read(&pblk->compl_writes),
+			atomic_read(&pblk->inflight_meta),
+			atomic_read(&pblk->compl_meta),
+			atomic_read(&pblk->recov_writes),
+			atomic_read(&pblk->recov_gc_writes),
+			atomic_read(&pblk->requeued_writes),
+			atomic_read(&pblk->sync_reads));
+}
+
+static ssize_t pblk_sysfs_write_buffer_vb(struct pblk *pblk, char *page)
+{
+	return pblk_rb_sysfs_vb(&pblk->rwb, page);
+}
+#endif
+
+enum {
+	PBLK_SEE_ONLY_LINE_META = 0,
+	PBLK_SEE_META_AND_LBAS = 1,
+	PBLK_SEE_META_AND_LBAS_F = 3,
+};
+
+static void __pblk_sysfs_line_meta(struct pblk *pblk, struct pblk_line *line,
+				   int cmd)
+{
+	u64 *lba_list;
+	int ret;
+
+	ret = pblk_line_read_smeta(pblk, line);
+	if (ret) {
+		pr_err("pblk: line %d read smeta failed (%d)\n", line->id, ret);
+		return;
+	}
+
+	pr_info("pblk: smeta line: %d\n", line->id);
+	pr_info("\tsmeta: id: %d\n", line->smeta->id);
+	pr_info("\tsmeta: type: %d\n", line->smeta->line_type);
+	pr_info("\tsmeta: seq_nr: %llu\n", line->smeta->seq_nr);
+	pr_info("\tsmeta: slun: %d\n", line->smeta->slun);
+	pr_info("\tsmeta: nr_luns: %d\n", line->smeta->nr_luns);
+	pr_info("\tsmeta: p_id: %d\n", line->smeta->p_id);
+	pr_info("\tsmeta: p_slun: %d\n", line->smeta->p_slun);
+	pr_info("\tsmeta: smeta_len: %d\n", line->smeta->smeta_len);
+	pr_info("\tsmeta: crc: %d\n", line->smeta->crc);
+
+	ret = pblk_line_read_emeta(pblk, line);
+	if (ret) {
+		pr_err("pblk: line %d read emeta failed (%d)\n", line->id, ret);
+		return;
+	}
+
+	pr_info("pblk: emeta line: %d\n", line->id);
+	pr_info("\temeta: id: %d\n", line->emeta->id);
+	pr_info("\temeta: type: %d\n", line->emeta->line_type);
+	pr_info("\temeta: seq_nr: %llu\n", line->emeta->seq_nr);
+	pr_info("\temeta: slun: %d\n", line->emeta->slun);
+	pr_info("\temeta: nr_luns: %d\n", line->emeta->nr_luns);
+	pr_info("\temeta: nr_lbas: %d\n", line->emeta->nr_lbas);
+	pr_info("\temeta: n_id: %d\n", line->emeta->n_id);
+	pr_info("\temeta: n_slun: %d\n", line->emeta->n_slun);
+	pr_info("\temeta: emeta_len: %d\n", line->emeta->emeta_len);
+	pr_info("\temeta: crc: %d\n", line->emeta->crc);
+
+	lba_list = pblk_recov_get_lba_list(pblk, line->emeta);
+	if (!lba_list) {
+		pr_info("pblk: emeta CRC failed\n");
+		if (cmd != PBLK_SEE_META_AND_LBAS_F)
+			return;
+	} else {
+		pr_info("pblk: emeta CRC correct\n");
+	}
+
+	if (cmd & PBLK_SEE_META_AND_LBAS) {
+		int i;
+
+		for (i = 0; i < line->emeta->nr_lbas; i++) {
+			pr_info("pblk: emeta lbas:\n");
+			pr_info("\tpos:%d, lba:%llu\n", i, lba_list[i]);
+		}
+	}
+}
+
+static ssize_t pblk_sysfs_line_bb(struct pblk *pblk, const char *page,
+				    ssize_t len)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line *line;
+	size_t c_len;
+	int bit = -1;
+	int nr_bbs;
+	int line_id;
+
+	c_len = strcspn(page, "\n");
+	if (c_len >= len)
+		return -EINVAL;
+
+	if (kstrtouint(page, 0, &line_id))
+		return -EINVAL;
+
+	if (line_id > l_mg->nr_lines) {
+		pr_err("pblk: line %d out-of-bound (max: %d)\n",
+				line_id, l_mg->nr_lines);
+		return -EINVAL;
+	}
+
+	line = &pblk->lines[line_id];
+	nr_bbs = bitmap_weight(line->blk_bitmap, lm->blk_per_line);
+
+	pr_info("pblk: line %d, nr_bb:%d, smeta:%d, emeta:%d/%d\n",
+				line->id, nr_bbs, lm->smeta_sec,
+				lm->emeta_sec, lm->emeta_bb);
+	while ((bit = find_next_bit(line->blk_bitmap, lm->blk_per_line,
+					bit + 1)) < lm->blk_per_line)
+		pr_info("bb: %d\n", bit);
+
+	return len;
+}
+
+static ssize_t pblk_sysfs_line_meta(struct pblk *pblk, const char *page,
+				    ssize_t len)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line *line;
+	struct line_smeta *smeta;
+	struct line_emeta *emeta;
+	size_t c_len;
+	int line_id, cmd;
+	int cur_data = -1, cur_log = -1;
+
+	c_len = strcspn(page, "\n");
+	if (c_len >= len)
+		return -EINVAL;
+
+	if (sscanf(page, "%d-%d", &line_id, &cmd) != 2)
+		return -EINVAL;
+
+	if (line_id > l_mg->nr_lines) {
+		pr_err("pblk: line %d out-of-bound (max: %d)\n",
+				line_id, l_mg->nr_lines);
+		return -EINVAL;
+	}
+
+	smeta = pblk_malloc(lm->smeta_len, l_mg->smeta_alloc_type, GFP_KERNEL);
+	if (!smeta)
+		goto out;
+	memset(smeta, 0, lm->smeta_len);
+
+	emeta = pblk_malloc(lm->emeta_len, l_mg->emeta_alloc_type, GFP_KERNEL);
+	if (!emeta)
+		goto free_smeta;
+	memset(emeta, 0, lm->emeta_len);
+
+	if (line_id != -1) {
+		line = &pblk->lines[line_id];
+		spin_lock(&line->lock);
+		if (line->type == PBLK_LINETYPE_FREE) {
+			pr_info("pblk: line: %d is free\n", line->id);
+			spin_unlock(&line->lock);
+			goto free_emeta;
+		} else if (line->type == PBLK_LINESTATE_BAD) {
+			pr_info("pblk: line: %d is bad\n", line->id);
+			spin_unlock(&line->lock);
+			goto free_emeta;
+		}
+		spin_unlock(&line->lock);
+
+		spin_lock(&l_mg->free_lock);
+		if (l_mg->data_line)
+			cur_data = l_mg->data_line->id;
+		if (l_mg->log_line)
+			cur_log = l_mg->log_line->id;
+		spin_unlock(&l_mg->free_lock);
+
+		pr_info("pblk: line: %d\t%d\t%d\t%d\t%d\t%d\n",
+				line->id, line->seq_nr, line->vsc, line->state,
+				line->type, line->gc_group);
+
+		if (line->id == cur_data) {
+			pr_info("pblk: cannot read metadata (active data line)\n");
+			goto free_emeta;
+		} else if (line->id == cur_log) {
+			pr_info("pblk: cannot read metadata (active log line)\n");
+			goto free_emeta;
+		}
+
+		line->smeta = smeta;
+		line->emeta = emeta;
+
+		__pblk_sysfs_line_meta(pblk, line, cmd);
+	} else {
+		struct list_head *group_list;
+		int i = 0;
+
+		spin_lock(&l_mg->gc_lock);
+		for (i = 0; i < PBLK_NR_GC_LISTS; i++) {
+			group_list = l_mg->gc_lists[i];
+			list_for_each_entry(line, group_list, list) {
+				spin_lock(&line->lock);
+				if (line->type != PBLK_LINESTATE_CLOSED) {
+					pr_info("pblk: line: %d corrupted\n",
+								line->id);
+					spin_unlock(&line->lock);
+					continue;
+				}
+				spin_unlock(&line->lock);
+
+				line->smeta = smeta;
+				line->emeta = emeta;
+
+				__pblk_sysfs_line_meta(pblk, line, cmd);
+			}
+		}
+		spin_unlock(&l_mg->gc_lock);
+	}
+
+free_emeta:
+	pblk_mfree(emeta, l_mg->emeta_alloc_type);
+free_smeta:
+	pblk_mfree(smeta, l_mg->smeta_alloc_type);
+out:
+	return len;
+}
+
+static ssize_t pblk_sysfs_rate_store(struct pblk *pblk, const char *page,
+				     size_t len)
+{
+	size_t c_len;
+	int value;
+
+	c_len = strcspn(page, "\n");
+	if (c_len >= len)
+		return -EINVAL;
+
+	if (kstrtouint(page, 0, &value))
+		return -EINVAL;
+
+	pblk_rl_set_gc_rsc(&pblk->rl, value);
+
+	return len;
+}
+
+static ssize_t pblk_sysfs_gc_force(struct pblk *pblk, const char *page,
+				   size_t len)
+{
+	size_t c_len;
+	int force;
+
+	c_len = strcspn(page, "\n");
+	if (c_len >= len)
+		return -EINVAL;
+
+	if (kstrtouint(page, 0, &force))
+		return -EINVAL;
+
+	if (force < 0 || force > 1)
+		return -EINVAL;
+
+	pblk_gc_sysfs_force(pblk, force);
+
+	return len;
+}
+
+#ifdef CONFIG_NVM_DEBUG
+static ssize_t pblk_sysfs_l2p_map_print(struct pblk *pblk, const char *page,
+					ssize_t len)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct bio *bio;
+	struct ppa_addr ppa;
+	struct nvm_rq rqd;
+	struct pblk_sec_meta *meta_list;
+	void *data;
+	dma_addr_t dma_meta_list;
+	sector_t lba_init, lba_end;
+	sector_t i;
+	size_t c_len;
+	u64 lba;
+	int ret;
+	DECLARE_COMPLETION_ONSTACK(wait);
+
+	c_len = strcspn(page, "\n");
+	if (c_len >= len)
+		return -EINVAL;
+
+	if (sscanf(page, "%llu-%llu", (unsigned long long *)&lba_init,
+					(unsigned long long *)&lba_end) != 2)
+		return -EINVAL;
+
+	meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL, &dma_meta_list);
+	if (!meta_list)
+		return -ENOMEM;
+
+	data = kcalloc(pblk->max_write_pgs, geo->sec_size, GFP_KERNEL);
+	if (!data)
+		goto free_meta_list;
+
+	for (i = lba_init; i < lba_end; i++) {
+		ppa = pblk_get_lba_map(pblk, i);
+
+		if (ppa_empty(ppa)) {
+			pr_info("pblk: lba:%lu - ppa: empty\n", i);
+			continue;
+		} else if (ppa.c.is_cached) {
+			pr_info("pblk: lba:%lu - ppa: cacheline:%llu\n",
+				i, (u64)ppa.c.line);
+				continue;
+		}
+
+		/* Default: ppa in media */
+		bio = bio_map_kern(dev->q, data, geo->sec_size, GFP_KERNEL);
+		if (IS_ERR(bio))
+			goto free_data;
+
+		memset(&rqd, 0, sizeof(struct nvm_rq));
+
+		bio->bi_iter.bi_sector = 0; /* artificial bio */
+		bio_set_op_attrs(bio, REQ_OP_READ, 0);
+		bio->bi_private = &wait;
+		bio->bi_end_io = pblk_end_bio_sync;
+
+		rqd.bio = bio;
+		rqd.opcode = NVM_OP_PREAD;
+		rqd.flags = pblk_set_read_mode(pblk);
+		rqd.meta_list = meta_list;
+		rqd.nr_ppas = 1;
+		rqd.ppa_addr = ppa;
+		rqd.dma_meta_list = dma_meta_list;
+		rqd.end_io = NULL;
+
+		ret = pblk_submit_io(pblk, &rqd);
+		if (ret) {
+			bio_put(bio);
+			goto free_data;
+		}
+		wait_for_completion_io(&wait);
+		bio_put(bio);
+
+		if (rqd.error)
+			lba = ADDR_EMPTY;
+		else
+			lba = meta_list[0].lba;
+
+		pr_info("pblk: lba:%lu(oob:%llu) - ppa: %llx: ch:%d,lun:%d,blk:%d,pg:%d,pl:%d,sec:%d\n",
+			i, lba,
+			ppa.ppa,
+			ppa.g.ch,
+			ppa.g.lun,
+			ppa.g.blk,
+			ppa.g.pg,
+			ppa.g.pl,
+			ppa.g.sec);
+	}
+
+free_data:
+	kfree(data);
+free_meta_list:
+	nvm_dev_dma_free(dev->parent, meta_list, dma_meta_list);
+
+	return len;
+}
+
+static ssize_t pblk_sysfs_l2p_map_sanity(struct pblk *pblk, const char *page,
+					 ssize_t len)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	size_t c_len;
+	struct ppa_addr ppa, l2p_ppa;
+	void *read_sec;
+	struct nvm_rq *rqd;
+	struct bio *bio;
+	sector_t lba_init, lba_end;
+	sector_t i;
+	DECLARE_COMPLETION_ONSTACK(wait);
+
+	c_len = strcspn(page, "\n");
+	if (c_len >= len)
+		return -EINVAL;
+
+	if (sscanf(page, "%llx-%lu-%lu", &ppa.ppa, &lba_init, &lba_end) != 3)
+		return -EINVAL;
+
+	if (lba_end == 0) {
+		lba_init = 0;
+		lba_end = pblk->rl.nr_secs;
+	}
+
+	if (lba_end > pblk->rl.nr_secs) {
+		pr_err("pblk: Incorrect lba limit\n");
+		goto out;
+	}
+
+	spin_lock(&pblk->trans_lock);
+	for (i = lba_init; i < lba_end; i++) {
+		l2p_ppa = pblk->trans_map[i];
+
+		if (ppa.ppa == l2p_ppa.ppa)
+			pr_debug("pblk: lba:%lu - ppa: %llx: ch:%d,lun:%d,blk:%d,pg:%d,pl:%d,sec:%d\n",
+				i,
+				ppa.ppa,
+				ppa.g.ch,
+				ppa.g.lun,
+				ppa.g.blk,
+				ppa.g.pg,
+				ppa.g.pl,
+				ppa.g.sec);
+	}
+	spin_unlock(&pblk->trans_lock);
+
+	read_sec = kmalloc(geo->sec_size, GFP_KERNEL);
+	if (!read_sec)
+		goto out;
+
+	bio = bio_map_kern(dev->q, read_sec, geo->sec_size, GFP_KERNEL);
+	if (!bio) {
+		pr_err("pblk: could not allocate recovery bio\n");
+		goto out;
+	}
+
+	rqd = pblk_alloc_rqd(pblk, READ);
+	if (IS_ERR(rqd)) {
+		pr_err("pblk: not able to create write req.\n");
+		bio_put(bio);
+		goto out;
+	}
+
+	bio->bi_iter.bi_sector = 0;
+	bio_set_op_attrs(bio, REQ_OP_READ, 0);
+	bio->bi_end_io = pblk_end_bio_sync;
+	bio->bi_private = &wait;
+
+	rqd->opcode = NVM_OP_PREAD;
+	rqd->bio = bio;
+	rqd->meta_list = NULL;
+	rqd->flags = pblk_set_read_mode(pblk);
+	rqd->end_io = NULL;
+
+	if (nvm_set_rqd_ppalist(dev, rqd, &ppa, 1, 0)) {
+		pr_err("pblk: could not set rqd ppa list\n");
+		goto out;
+	}
+
+	if (pblk_submit_io(pblk, rqd)) {
+		pr_err("pblk: I/O submission failed\n");
+		nvm_free_rqd_ppalist(dev, rqd);
+		goto out;
+	}
+	wait_for_completion_io(&wait);
+
+	if (rqd->error) {
+		struct ppa_addr p;
+
+		p = dev_to_generic_addr(pblk->dev, rqd->ppa_addr);
+		pr_err("pblk: read failed (%u)\n", bio->bi_error);
+		print_ppa(&p, "rqd", bio->bi_error);
+		goto out;
+	}
+
+out:
+	return len;
+}
+#endif
+
+static struct attribute sys_write_luns = {
+	.name = "write_luns",
+	.mode = 0444,
+};
+
+static struct attribute sys_rate_limiter_attr = {
+	.name = "rate_limiter",
+	.mode = 0444,
+};
+
+static struct attribute sys_gc_state = {
+	.name = "gc_state",
+	.mode = 0444,
+};
+
+static struct attribute sys_errors_attr = {
+	.name = "errors",
+	.mode = 0444,
+};
+
+static struct attribute sys_rb_attr = {
+	.name = "write_buffer",
+	.mode = 0444,
+};
+
+static struct attribute sys_stats_ppaf_attr = {
+	.name = "ppa_format",
+	.mode = 0444,
+};
+
+static struct attribute sys_lines_attr = {
+	.name = "lines",
+	.mode = 0444,
+};
+
+static struct attribute sys_lines_info_attr = {
+	.name = "lines_info",
+	.mode = 0444,
+};
+
+static struct attribute sys_gc_force = {
+	.name = "gc_force",
+	.mode = 0200,
+};
+
+static struct attribute sys_gc_rl_max = {
+	.name = "gc_rl_max",
+	.mode = 0200,
+};
+
+static struct attribute sys_line_meta_attr = {
+	.name = "line_metadata",
+	.mode = 0644,
+};
+
+static struct attribute sys_line_bb_attr = {
+	.name = "line_bb",
+	.mode = 0644,
+};
+
+#ifdef CONFIG_NVM_DEBUG
+static struct attribute sys_stats_debug_attr = {
+	.name = "stats",
+	.mode = 0444,
+};
+
+static struct attribute sys_rb_vb_attr = {
+	.name = "write_buffer_vb",
+	.mode = 0444,
+};
+
+static struct attribute sys_l2p_map_attr = {
+	.name = "l2p_map",
+	.mode = 0644,
+};
+
+static struct attribute sys_l2p_sanity_attr = {
+	.name = "l2p_sanity",
+	.mode = 0644,
+};
+#endif
+
+static struct attribute *pblk_attrs[] = {
+	&sys_write_luns,
+	&sys_rate_limiter_attr,
+	&sys_errors_attr,
+	&sys_gc_state,
+	&sys_gc_force,
+	&sys_gc_rl_max,
+	&sys_rb_attr,
+	&sys_stats_ppaf_attr,
+	&sys_lines_attr,
+	&sys_lines_info_attr,
+	&sys_line_meta_attr,
+	&sys_line_bb_attr,
+#ifdef CONFIG_NVM_DEBUG
+	&sys_stats_debug_attr,
+	&sys_rb_vb_attr,
+	&sys_l2p_map_attr,
+	&sys_l2p_sanity_attr,
+#endif
+	NULL,
+};
+
+static ssize_t pblk_sysfs_show(struct kobject *kobj, struct attribute *attr,
+			       char *buf)
+{
+	struct pblk *pblk = container_of(kobj, struct pblk, kobj);
+
+	if (strcmp(attr->name, "rate_limiter") == 0)
+		return pblk_sysfs_rate_limiter(pblk, buf);
+	else if (strcmp(attr->name, "write_luns") == 0)
+		return pblk_sysfs_luns_show(pblk, buf);
+	else if (strcmp(attr->name, "gc_state") == 0)
+		return pblk_sysfs_gc_state_show(pblk, buf);
+	else if (strcmp(attr->name, "errors") == 0)
+		return pblk_sysfs_stats(pblk, buf);
+	else if (strcmp(attr->name, "write_buffer") == 0)
+		return pblk_sysfs_write_buffer(pblk, buf);
+	else if (strcmp(attr->name, "ppa_format") == 0)
+		return pblk_sysfs_ppaf(pblk, buf);
+	else if (strcmp(attr->name, "lines") == 0)
+		return pblk_sysfs_lines(pblk, buf);
+	else if (strcmp(attr->name, "lines_info") == 0)
+		return pblk_sysfs_lines_info(pblk, buf);
+#ifdef CONFIG_NVM_DEBUG
+	else if (strcmp(attr->name, "stats") == 0)
+		return pblk_sysfs_stats_debug(pblk, buf);
+	else if (strcmp(attr->name, "write_buffer_vb") == 0)
+		return pblk_sysfs_write_buffer_vb(pblk, buf);
+#endif
+	return 0;
+}
+
+static ssize_t pblk_sysfs_store(struct kobject *kobj, struct attribute *attr,
+				const char *buf, size_t len)
+{
+	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)
+		return pblk_sysfs_gc_force(pblk, buf, len);
+	else if (strcmp(attr->name, "line_metadata") == 0)
+		return pblk_sysfs_line_meta(pblk, buf, len);
+	else if (strcmp(attr->name, "line_bb") == 0)
+		return pblk_sysfs_line_bb(pblk, buf, len);
+#ifdef CONFIG_NVM_DEBUG
+	else if (strcmp(attr->name, "l2p_map") == 0)
+		return pblk_sysfs_l2p_map_print(pblk, buf, len);
+	else if (strcmp(attr->name, "l2p_sanity") == 0)
+		return pblk_sysfs_l2p_map_sanity(pblk, buf, len);
+#endif
+
+	return 0;
+}
+
+static const struct sysfs_ops pblk_sysfs_ops = {
+	.show = pblk_sysfs_show,
+	.store = pblk_sysfs_store,
+};
+
+static struct kobj_type pblk_ktype = {
+	.sysfs_ops	= &pblk_sysfs_ops,
+	.default_attrs	= pblk_attrs,
+};
+
+int pblk_sysfs_init(struct gendisk *tdisk)
+{
+	struct pblk *pblk = tdisk->private_data;
+	struct device *parent_dev = disk_to_dev(pblk->disk);
+	int ret;
+
+	ret = kobject_init_and_add(&pblk->kobj, &pblk_ktype,
+					kobject_get(&parent_dev->kobj),
+					"%s", "pblk");
+	if (ret) {
+		pr_err("pblk: could not register %s/pblk\n",
+						tdisk->disk_name);
+		return ret;
+	}
+
+	kobject_uevent(&pblk->kobj, KOBJ_ADD);
+	return 0;
+}
+
+void pblk_sysfs_exit(struct gendisk *tdisk)
+{
+	struct pblk *pblk = tdisk->private_data;
+
+	kobject_uevent(&pblk->kobj, KOBJ_REMOVE);
+	kobject_del(&pblk->kobj);
+	kobject_put(&pblk->kobj);
+}
+
diff --git a/drivers/lightnvm/pblk-write.c b/drivers/lightnvm/pblk-write.c
new file mode 100644
index 0000000..80fdd5a
--- /dev/null
+++ b/drivers/lightnvm/pblk-write.c
@@ -0,0 +1,407 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@xxxxxxxxxxxx>
+ *                  Matias Bjorling <matias@xxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * pblk-write.c - pblk's write path from write buffer to media
+ */
+
+#include "pblk.h"
+
+static void pblk_sync_line(struct pblk *pblk, struct pblk_line *line)
+{
+#ifdef CONFIG_NVM_DEBUG
+	atomic_inc(&pblk->sync_writes);
+#endif
+
+	/* Counter protected by rb sync lock */
+	line->left_ssecs--;
+	if (!line->left_ssecs)
+		pblk_line_run_ws(pblk, line, pblk_line_close);
+}
+
+static unsigned long pblk_end_w_bio(struct pblk *pblk, struct nvm_rq *rqd,
+				    struct pblk_c_ctx *c_ctx)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct bio *original_bio;
+	unsigned long ret;
+	int i;
+
+	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_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_add(c_ctx->nr_valid, &pblk->compl_writes);
+#endif
+
+	ret = pblk_rb_sync_advance(&pblk->rwb, c_ctx->nr_valid);
+
+	if (rqd->meta_list)
+		nvm_dev_dma_free(dev->parent, rqd->meta_list,
+							rqd->dma_meta_list);
+
+	bio_put(rqd->bio);
+	pblk_free_rqd(pblk, rqd, WRITE);
+
+	return ret;
+}
+
+static unsigned long pblk_end_queued_w_bio(struct pblk *pblk,
+					   struct nvm_rq *rqd,
+					   struct pblk_c_ctx *c_ctx)
+{
+	list_del(&c_ctx->list);
+	return pblk_end_w_bio(pblk, rqd, c_ctx);
+}
+
+static void pblk_complete_write(struct pblk *pblk, struct nvm_rq *rqd,
+				struct pblk_c_ctx *c_ctx)
+{
+	struct pblk_c_ctx *c, *r;
+	unsigned long flags;
+	unsigned long pos;
+
+#ifdef CONFIG_NVM_DEBUG
+	atomic_sub(c_ctx->nr_valid, &pblk->inflight_writes);
+#endif
+
+	pblk_up_rq(pblk, rqd->ppa_list, rqd->nr_ppas, c_ctx->lun_bitmap);
+
+	pos = pblk_rb_sync_init(&pblk->rwb, &flags);
+	if (pos == c_ctx->sentry) {
+		pos = pblk_end_w_bio(pblk, rqd, c_ctx);
+
+retry:
+		list_for_each_entry_safe(c, r, &pblk->compl_list, list) {
+			rqd = nvm_rq_from_c_ctx(c);
+			if (c->sentry == pos) {
+				pos = pblk_end_queued_w_bio(pblk, rqd, c);
+				goto retry;
+			}
+		}
+	} else {
+		WARN_ON(nvm_rq_from_c_ctx(c_ctx) != rqd);
+		list_add_tail(&c_ctx->list, &pblk->compl_list);
+	}
+	pblk_rb_sync_end(&pblk->rwb, &flags);
+}
+
+/* When a write fails, we are not sure whether the block has grown bad or a page
+ * range is more susceptible to write errors. If a high number of pages fail, we
+ * assume that the block is bad and we mark it accordingly. In all cases, we
+ * remap and resubmit the failed entries as fast as possible; if a flush is
+ * waiting on a completion, the whole stack would stall otherwise.
+ */
+static void pblk_end_w_fail(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	void *comp_bits = &rqd->ppa_status;
+	struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
+	struct pblk_rec_ctx *recovery;
+	struct ppa_addr *ppa_list = rqd->ppa_list;
+	int nr_ppas = rqd->nr_ppas;
+	unsigned int c_entries;
+	int bit, ret;
+
+	if (unlikely(nr_ppas == 1))
+		ppa_list = &rqd->ppa_addr;
+
+	recovery = mempool_alloc(pblk->rec_pool, GFP_ATOMIC);
+	if (!recovery) {
+		pr_err("pblk: could not allocate recovery context\n");
+		return;
+	}
+	INIT_LIST_HEAD(&recovery->failed);
+
+	bit = -1;
+	while ((bit = find_next_bit(comp_bits, nr_ppas, bit + 1)) < nr_ppas) {
+		struct pblk_rb_entry *entry;
+		struct ppa_addr ppa;
+
+		/* Logic error */
+		BUG_ON(bit > c_ctx->nr_valid);
+
+		ppa = ppa_list[bit];
+		entry = pblk_rb_sync_scan_entry(&pblk->rwb, &ppa);
+		if (!entry) {
+			pr_err("pblk: could not scan entry on write failure\n");
+			goto out;
+		}
+
+		/* The list is filled first and emptied afterwards. No need for
+		 * protecting it with a lock
+		 */
+		list_add_tail(&entry->index, &recovery->failed);
+	}
+
+	c_entries = find_first_bit(comp_bits, nr_ppas);
+	ret = pblk_recov_setup_rq(pblk, c_ctx, recovery, comp_bits, c_entries);
+	if (ret) {
+		pr_err("pblk: could not recover from write failure\n");
+		goto out;
+	}
+
+	INIT_WORK(&recovery->ws_rec, pblk_submit_rec);
+	queue_work(pblk->kw_wq, &recovery->ws_rec);
+
+out:
+	pblk_complete_write(pblk, rqd, c_ctx);
+}
+
+static void pblk_end_io_write(struct nvm_rq *rqd)
+{
+	struct pblk *pblk = rqd->private;
+	struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
+
+	if (rqd->error) {
+		pblk_log_write_err(pblk, rqd);
+		return pblk_end_w_fail(pblk, rqd);
+	}
+#ifdef CONFIG_NVM_DEBUG
+	else
+		BUG_ON(rqd->bio->bi_error);
+#endif
+
+	pblk_complete_write(pblk, rqd, c_ctx);
+}
+
+static int pblk_alloc_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
+			   unsigned int nr_secs)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+
+	/* Setup write request */
+	rqd->opcode = NVM_OP_PWRITE;
+	rqd->nr_ppas = nr_secs;
+	rqd->flags = pblk_set_progr_mode(pblk, WRITE);
+	rqd->private = pblk;
+	rqd->end_io = pblk_end_io_write;
+
+	rqd->meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
+							&rqd->dma_meta_list);
+	if (!rqd->meta_list)
+		return -ENOMEM;
+
+	if (unlikely(nr_secs == 1))
+		return 0;
+
+	rqd->ppa_list = rqd->meta_list + pblk_dma_meta_size;
+	rqd->dma_ppa_list = rqd->dma_meta_list + pblk_dma_meta_size;
+
+	return 0;
+}
+
+static int pblk_setup_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
+			   struct pblk_c_ctx *c_ctx)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_line *e_line = pblk_line_get_data_next(pblk);
+	struct ppa_addr erase_ppa;
+	unsigned int valid = c_ctx->nr_valid;
+	unsigned int padded = c_ctx->nr_padded;
+	unsigned int nr_secs = valid + padded;
+	unsigned long *lun_bitmap;
+	int ret = 0;
+
+	lun_bitmap = kzalloc(lm->lun_bitmap_len, GFP_KERNEL);
+	if (!lun_bitmap) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	c_ctx->lun_bitmap = lun_bitmap;
+
+	ret = pblk_alloc_w_rq(pblk, rqd, nr_secs);
+	if (ret) {
+		kfree(lun_bitmap);
+		goto out;
+	}
+
+	ppa_set_empty(&erase_ppa);
+	if (likely(!e_line || !e_line->left_eblks)) {
+		pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, valid, 0);
+	} else {
+		ret = pblk_map_erase_rq(pblk, rqd, c_ctx->sentry, lun_bitmap,
+							valid, &erase_ppa);
+		if (ret)
+			goto out;
+	}
+
+out:
+	if (unlikely(!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;
+
+			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));
+			pr_err("pblk: could not erase preparation line\n");
+		}
+	}
+
+	return ret;
+}
+
+int pblk_setup_w_rec_rq(struct pblk *pblk, struct nvm_rq *rqd,
+			struct pblk_c_ctx *c_ctx)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	unsigned long *lun_bitmap;
+	int ret;
+
+	lun_bitmap = kzalloc(lm->lun_bitmap_len, GFP_KERNEL);
+	if (!lun_bitmap)
+		return -ENOMEM;
+
+	c_ctx->lun_bitmap = lun_bitmap;
+
+	ret = pblk_alloc_w_rq(pblk, rqd, rqd->nr_ppas);
+	if (ret)
+		return ret;
+
+	pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, c_ctx->nr_valid, 0);
+
+	rqd->ppa_status = (u64)0;
+	rqd->flags = pblk_set_progr_mode(pblk, WRITE);
+
+	return ret;
+}
+
+static int pblk_calc_secs_to_sync(struct pblk *pblk, unsigned long secs_avail,
+				  unsigned long secs_to_flush)
+{
+	int secs_to_sync;
+
+	secs_to_sync = pblk_calc_secs(pblk, secs_avail, secs_to_flush);
+
+#ifdef CONFIG_NVM_DEBUG
+	BUG_ON(!secs_to_sync && secs_to_flush);
+	BUG_ON(secs_to_sync > secs_avail && !secs_to_flush);
+	BUG_ON(secs_to_sync < 0 || secs_to_sync > pblk->max_write_pgs);
+#endif
+
+	return secs_to_sync;
+}
+
+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
+	 */
+	secs_avail = pblk_rb_read_count(&pblk->rwb);
+	if (!secs_avail)
+		return 1;
+
+	secs_to_flush = pblk_rb_sync_point_count(&pblk->rwb);
+	if (!secs_to_flush && secs_avail < pblk->max_write_pgs)
+		return 1;
+
+	rqd = pblk_alloc_rqd(pblk, WRITE);
+	if (IS_ERR(rqd)) {
+		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) {
+		pr_err("pblk: cannot allocate write bio\n");
+		goto fail_free_rqd;
+	}
+	bio->bi_iter.bi_sector = 0; /* artificial bio */
+	bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+	rqd->bio = bio;
+
+	secs_to_sync = pblk_calc_secs_to_sync(pblk, secs_avail, secs_to_flush);
+	if (secs_to_sync < 0) {
+		pr_err("pblk: bad buffer sync calculation\n");
+		goto fail_put_bio;
+	}
+
+	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) {
+		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");
+		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_add(secs_to_sync, &pblk->sub_writes);
+#endif
+
+	return 0;
+fail_free_bio:
+	if (c_ctx->nr_padded)
+		pblk_bio_free_pages(pblk, bio, secs_to_sync, c_ctx->nr_padded);
+fail_put_bio:
+	bio_put(bio);
+fail_free_rqd:
+	pblk_free_rqd(pblk, rqd, WRITE);
+
+	return 1;
+}
+
+int pblk_write_ts(void *data)
+{
+	struct pblk *pblk = data;
+
+	while (!kthread_should_stop()) {
+		if (!pblk_submit_write(pblk))
+			continue;
+		set_current_state(TASK_INTERRUPTIBLE);
+		io_schedule();
+	}
+
+	return 0;
+}
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
new file mode 100644
index 0000000..90310aa
--- /dev/null
+++ b/drivers/lightnvm/pblk.h
@@ -0,0 +1,958 @@
+/*
+ * Copyright (C) 2015 IT University of Copenhagen (rrpc.h)
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Matias Bjorling <matias@xxxxxxxxxxxx>
+ * Write buffering: Javier Gonzalez <javier@xxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * Implementation of a Physical Block-device target for Open-channel SSDs.
+ *
+ * Derived from rrpc.h
+ */
+
+#ifndef PBLK_H_
+#define PBLK_H_
+
+#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
+#include <linux/bio.h>
+#include <linux/module.h>
+#include <linux/kthread.h>
+#include <linux/vmalloc.h>
+#include <linux/crc32.h>
+
+#include <linux/lightnvm.h>
+
+/* Run only GC if less than 1/X blocks are free */
+#define GC_LIMIT_INVERSE 5
+#define GC_TIME_MSECS 1000
+
+#define PBLK_SECTOR (512)
+#define PBLK_EXPOSED_PAGE_SIZE (4096)
+#define PBLK_MAX_REQ_ADDRS (64)
+#define PBLK_MAX_REQ_ADDRS_PW (6)
+
+/* Max 512 LUNs per device */
+#define PBLK_MAX_LUNS_BITMAP (4)
+
+#define NR_PHY_IN_LOG (PBLK_EXPOSED_PAGE_SIZE / PBLK_SECTOR)
+
+#define pblk_for_each_lun(pblk, rlun, i) \
+		for ((i) = 0, rlun = &(pblk)->luns[0]; \
+			(i) < (pblk)->nr_luns; (i)++, rlun = &(pblk)->luns[(i)])
+
+#define ERASE 2 /* READ = 0, WRITE = 1 */
+
+enum {
+	/* IO Types */
+	PBLK_IOTYPE_USER = 1,
+	PBLK_IOTYPE_GC = 2,
+
+	/* Matias: How come we do 64, 128, 256? why these values? */
+	/* Write buffer flags */
+	PBLK_FLUSH_ENTRY	= 1 << 6,
+	PBLK_WRITTEN_DATA	= 1 << 7,
+	PBLK_SUBMITTED_ENTRY	= 1 << 8,
+	PBLK_WRITABLE_ENTRY	= 1 << 9,
+};
+
+enum {
+	PBLK_BLK_ST_OPEN =	0x1,
+	PBLK_BLK_ST_CLOSED =	0x2,
+};
+
+struct pblk_sec_meta {
+	u64 reserved;
+	u64 lba;
+};
+
+#define pblk_dma_meta_size (sizeof(struct pblk_sec_meta) * PBLK_MAX_REQ_ADDRS)
+
+/* write completion context */
+struct pblk_c_ctx {
+	struct list_head list;		/* Head for out-of-order completion */
+
+	unsigned long *lun_bitmap;	/* Luns used on current request */
+	unsigned int sentry;
+	unsigned int nr_valid;
+	unsigned int nr_padded;
+};
+
+/* Read context */
+struct pblk_r_ctx {
+	struct bio *orig_bio;
+};
+
+/* Recovery context */
+struct pblk_rec_ctx {
+	struct pblk *pblk;
+	struct nvm_rq *rqd;
+	struct list_head failed;
+	struct work_struct ws_rec;
+};
+
+/* Write context */
+struct pblk_w_ctx {
+	struct bio_list bios;		/* Original bios - used for completion
+					 * in REQ_FUA, REQ_FLUSH case
+					 */
+	sector_t lba;			/* Logic addr. associated with entry */
+	u64 paddr;			/* pblk line physical address */
+	struct ppa_addr ppa;		/* Physic addr. associated with entry */
+	int flags;			/* Write context flags */
+};
+
+struct pblk_rb_entry {
+	struct ppa_addr cacheline;	/* Cacheline for this entry */
+	void *data;			/* Pointer to data on this entry */
+	struct pblk_w_ctx w_ctx;	/* Context for this entry */
+	struct list_head index;		/* List head to enable indexes */
+};
+
+#define EMPTY_ENTRY (~0U)
+
+struct pblk_rb_pages {
+	struct page *pages;
+	int order;
+	struct list_head list;
+};
+
+struct pblk_rb {
+	struct pblk_rb_entry *entries;	/* Ring buffer entries */
+	unsigned int mem;		/* Write offset - points to next
+					 * writable entry in memory
+					 */
+	unsigned int subm;		/* Read offset - points to last entry
+					 * that has been submitted to the media
+					 * to be persisted
+					 */
+	unsigned int sync;		/* Synced - backpointer that signals
+					 * the last submitted entry that has
+					 * been successfully persisted to media
+					 */
+	unsigned int sync_point;	/* Sync point - last entry that must be
+					 * flushed to the media. Used with
+					 * REQ_FLUSH and REQ_FUA
+					 */
+	unsigned int l2p_update;	/* l2p update point - next entry for
+					 * which l2p mapping will be updated to
+					 * contain a device ppa address (instead
+					 * of a cacheline
+					 */
+	unsigned int nr_entries;	/* Number of entries in write buffer -
+					 * must be a power of two
+					 */
+	unsigned int seg_size;		/* Size of the data segments being
+					 * stored on each entry. Typically this
+					 * will be 4KB
+					 */
+
+	struct list_head pages;		/* List of data pages */
+
+	spinlock_t w_lock;		/* Write lock */
+	spinlock_t s_lock;		/* Sync lock */
+
+#ifdef CONFIG_NVM_DEBUG
+	atomic_t inflight_sync_point;	/* Not served REQ_FLUSH | REQ_FUA */
+#endif
+};
+
+#define PBLK_RECOVERY_SECTORS 16
+
+struct pblk_lun {
+	struct ppa_addr bppa;
+
+	u8 *bb_list;			/* Bad block list for LUN. Only used on
+					 * bring up. Bad blocks are managed
+					 * within lines on run-time.
+					 */
+
+	struct semaphore wr_sem;
+};
+
+struct pblk_gc {
+	int gc_active;
+	int gc_enabled;
+	int gc_forced;
+
+	spinlock_t lock;
+};
+
+struct pblk_rl {
+	unsigned int high_pw;	/* Upper threshold for rate limiter (free run -
+				 * user I/O rate limiter. Given as a power-of-2
+				 */
+	unsigned int low_pw;	/* Lower threshold for rate limiter (user I/O
+				 * rate limiter - stall). Given as a power-of-2
+				 */
+
+#define PBLK_USER_LOW_THRS 50	/* full stop at 2 percent of available
+				 * blocks
+				 */
+#define PBLK_USER_HIGH_THRS 4	/* begin write limit at 25 percent
+				 * available blks
+				 */
+
+	int rb_windows_pw;	/* Number of rate windows in the write buffer
+				 * given as a power-of-2. This guarantees that
+				 * when user I/O is being rate limited, there
+				 * will be reserved enough space for the GC to
+				 * place its payload. A window is of
+				 * pblk->max_write_pgs size, which in NVMe is
+				 * 64, i.e., 256kb.
+				 */
+	int rb_budget;		/* Total number of entries available for I/O */
+	int rb_user_max;	/* Max buffer entries available for user I/O */
+	int 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_gc_cnt;		/* GC I/O buffer counter */
+
+	int rb_user_active;
+	struct timer_list u_timer;
+
+	unsigned long long nr_secs;
+	unsigned long total_blocks;
+	unsigned long free_blocks;
+
+	spinlock_t *lock;
+};
+
+#define PBLK_LINE_NR_LUN_BITMAP 2
+#define PBLK_LINE_NR_SEC_BITMAP 2
+#define PBLK_LINE_EMPTY (~0U)
+
+enum {
+	/* Line Types */
+	PBLK_LINETYPE_FREE = 0,
+	PBLK_LINETYPE_LOG = 1,
+	PBLK_LINETYPE_DATA = 2,
+
+	/* Line state */
+	PBLK_LINESTATE_FREE = 10,
+	PBLK_LINESTATE_OPEN = 11,
+	PBLK_LINESTATE_CLOSED = 12,
+	PBLK_LINESTATE_GC = 13,
+	PBLK_LINESTATE_BAD = 14,
+	PBLK_LINESTATE_CORRUPT = 15,
+
+	/* GC group */
+	PBLK_LINEGC_NONE = 20,
+	PBLK_LINEGC_EMPTY = 21,
+	PBLK_LINEGC_LOW = 22,
+	PBLK_LINEGC_MID = 23,
+	PBLK_LINEGC_HIGH = 24,
+	PBLK_LINEGC_FULL = 25,
+};
+
+/*
+ * Medatada Layout:
+ *	1. struct pblk_smeta
+ *	2. nr_luns bits (u64 format) forming current lun bitmap
+ *	3. nr_luns bits (u64 format) forming previous lun bitmap
+ */
+struct line_smeta {
+	u32 crc;
+
+	/* Current line metadata */
+	u32 id;			/* Line id for current line */
+	u32 line_type;		/* Line type */
+	u64 seq_nr;		/* Sequence number for current line */
+	u32 slun;		/* Start LUN for this line */
+	u32 nr_luns;		/* Number of LUNs forming line */
+
+	/* Previous line metadata */
+	u32 p_id;		/* Line id for previous line */
+	u32 p_slun;		/* Start LUN for previous line */
+
+	u32 smeta_len;		/* Total length for smeta (included struct) */
+};
+
+/*
+ * Metadata Layout:
+ *	1. struct pblk_emeta
+ *	2. nr_lbas u64 forming lba list
+ *	TODO: Include in FTL Log
+ *	3. nr_lines (all) u32 invalid sector count (isc) (~0U: non-alloc line)
+ *	4. nr_luns bits (u64 format) forming line bad block bitmap
+ */
+struct line_emeta {
+	/* General */
+	/* TODO: FTL Log */
+
+	u32 crc;
+
+	/* Current line metadata */
+	u32 id;			/* Line id for current line */
+	u32 line_type;		/* Line type */
+	u64 seq_nr;		/* Sequence number for current line */
+	u32 slun;		/* Start LUN for this line */
+	u32 nr_luns;		/* Number of LUNs forming the current line */
+	u32 nr_lbas;		/* Number of lbas mapped in line */
+
+	/* Next line metadata */
+	u32 n_id;		/* Line id for next line */
+	u32 n_slun;		/* Start LUN for next line */
+
+	u32 emeta_len;		/* Total length for smeta (included struct) */
+};
+
+struct pblk_line {
+	struct pblk *pblk;
+	unsigned int id;		/* Line number corresponds to the
+					 * block line
+					 */
+	unsigned int seq_nr;		/* Unique line sequence number */
+
+	int state;			/* PBLK_LINESTATE_X */
+	int type;			/* PBLK_LINETYPE_X */
+	int gc_group;			/* PBLK_LINEGC_X */
+	struct list_head list;		/* Free, GC lists */
+
+	unsigned long *lun_bitmap;	/* Bitmap for LUNs mapped in line */
+
+	struct line_smeta *smeta;	/* Start metadata */
+	struct line_emeta *emeta;	/* End metadata */
+	int meta_line;			/* Metadata line id */
+	u64 smeta_ssec;			/* Sector where smeta starts */
+	u64 emeta_ssec;			/* Sector where emeta starts */
+
+	unsigned int sec_in_line;	/* Number of usable secs in line */
+
+	unsigned int blk_in_line;	/* Number of good blocks in line */
+	unsigned long *blk_bitmap;	/* Bitmap for valid/invalid blocks */
+	unsigned long *erase_bitmap;	/* Bitmap for erased blocks */
+
+	unsigned long *map_bitmap;	/* Bitmap for mapped sectors in line */
+	unsigned long *invalid_bitmap;	/* Bitmap for invalid sectors in line */
+
+	int left_eblks;			/* Blocks left for erasing */
+	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 vsc;		/* Valid sector count in line */
+
+	struct kref ref;		/* Write buffer L2P references */
+
+	spinlock_t lock;		/* Necessary for invalid_bitmap only */
+};
+
+#define PBLK_DATA_LINES 2
+
+enum{
+	PBLK_KMALLOC_META = 1,
+	PBLK_VMALLOC_META = 2,
+};
+
+struct pblk_line_metadata {
+	void *meta;
+};
+
+#define PBLK_NR_GC_LISTS 3
+
+struct pblk_line_mgmt {
+	int nr_lines;			/* Total number of full lines */
+	int nr_free_lines;		/* Number of full lines in free list */
+
+	/* Free lists - use free_lock */
+	struct list_head free_list;	/* Full lines ready to use */
+	struct list_head corrupt_list;	/* Full lines corrupted */
+	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_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 */
+
+	struct list_head gc_full_list;	/* Full lines ready to GC, no valid */
+	struct list_head gc_empty_list;	/* Full lines close, all valid */
+
+	struct pblk_line *log_line;	/* Current FTL log line */
+	struct pblk_line *data_line;	/* Current data line */
+	struct pblk_line *log_next;	/* Next FTL log line */
+	struct pblk_line *data_next;	/* Next data line */
+
+	/* Metadata allocation type: VMALLOC | KMALLOC */
+	int smeta_alloc_type;
+	int emeta_alloc_type;
+
+	/* Pre-allocated metadata for GC lines */
+	struct pblk_line_metadata gc_meta;
+
+	/* Pre-allocated metadata for data lines */
+	struct pblk_line_metadata sline_meta[PBLK_DATA_LINES];
+	struct pblk_line_metadata eline_meta[PBLK_DATA_LINES];
+	unsigned long meta_bitmap;
+
+	/* Helpers for fast bitmap calculations */
+	unsigned long *bb_template;
+	unsigned long *bb_aux;
+
+	unsigned long d_seq_nr;		/* Data line unique sequence number */
+	unsigned long l_seq_nr;		/* Log line unique sequence number */
+
+	spinlock_t free_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 emeta_bb;		/* Boundary for bb that affects emeta */
+	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 mid_thrs;		/* Threshold for GC mid list */
+	unsigned int high_thrs;		/* Threshold for GC high list */
+};
+
+struct pblk_addr_format {
+	u64	ch_mask;
+	u64	lun_mask;
+	u64	pln_mask;
+	u64	blk_mask;
+	u64	pg_mask;
+	u64	sec_mask;
+	u8	ch_offset;
+	u8	lun_offset;
+	u8	pln_offset;
+	u8	blk_offset;
+	u8	pg_offset;
+	u8	sec_offset;
+};
+
+#define NVM_MEM_PAGE_WRITE (8)
+
+struct pblk {
+	struct nvm_tgt_dev *dev;
+	struct gendisk *disk;
+
+	struct kobject kobj;
+
+	struct pblk_lun *luns;
+
+	struct pblk_line *lines;		/* Line array */
+	struct pblk_line_mgmt l_mg;		/* Line management */
+	struct pblk_line_meta lm;		/* Line metadata */
+
+	struct pblk_addr_format ppaf;
+
+	struct pblk_rb rwb;
+
+	struct bio_list requeue_bios;;		/* Requeued bios */
+
+	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
+			    * guarantee successful reads.
+			    */
+
+	/* capacity of devices when bad blocks are subtracted */
+	sector_t capacity;
+
+	/* pblk provisioning values. Used by rate limiter */
+	struct pblk_rl rl;
+
+#ifdef CONFIG_NVM_DEBUG
+	/* All debug counters apply to 4kb sector I/Os */
+	atomic_t inflight_writes;	/* Inflight writes (user and gc) */
+	atomic_t padded_writes;		/* Sectors padded due to flush/fua */
+	atomic_t nr_flush;		/* Number of flush/fua I/O */
+	atomic_t req_writes;		/* Sectors stored on write buffer */
+	atomic_t sub_writes;		/* Sectors submitted from buffer */
+	atomic_t sync_writes;		/* Sectors synced to media */
+	atomic_t compl_writes;		/* Sectors completed in write bio */
+	atomic_t inflight_meta;		/* Inflight metadata sectors */
+	atomic_t compl_meta;		/* Completed metadata sectors */
+	atomic_t inflight_reads;	/* Inflight sector read requests */
+	atomic_t sync_reads;		/* Completed sector read requests */
+	atomic_t recov_writes;		/* Sectors submitted from recovery */
+	atomic_t recov_gc_writes;	/* Sectors submitted from recovery GC */
+	atomic_t requeued_writes;	/* Sectors requeued in cache */
+#endif
+
+	spinlock_t lock;
+
+	unsigned long read_failed;
+	unsigned long read_empty;
+	unsigned long read_high_ecc;
+	unsigned long read_failed_gc;
+	unsigned long write_failed;
+	unsigned long erase_failed;
+
+	struct task_struct *ts_writer;
+
+	/* Simple translation map of logical addresses to physical addresses.
+	 * The logical addresses is known by the host system, while the physical
+	 * addresses are used when writing to the disk block device.
+	 */
+	struct ppa_addr *trans_map;
+	spinlock_t trans_lock;
+
+	struct list_head compl_list;
+
+	mempool_t *page_pool;
+	mempool_t *line_ws_pool;
+	mempool_t *rec_pool;
+	mempool_t *r_rq_pool;
+	mempool_t *w_rq_pool;
+	mempool_t *line_meta_pool;
+
+	struct timer_list gc_timer;
+	struct task_struct *ts_gc;
+	struct workqueue_struct *gc_wq;
+	struct workqueue_struct *kw_wq;
+
+	struct timer_list wtimer;
+
+	struct pblk_gc gc;
+};
+
+struct pblk_line_ws {
+	struct pblk *pblk;
+	void *priv;
+	struct work_struct ws;
+};
+
+#define pblk_r_rq_size (sizeof(struct nvm_rq) + sizeof(struct pblk_r_ctx))
+#define pblk_w_rq_size (sizeof(struct nvm_rq) + sizeof(struct pblk_c_ctx))
+
+/*
+ * pblk ring buffer operations
+ */
+int pblk_rb_init(struct pblk_rb *rb, struct pblk_rb_entry *rb_entry_base,
+		 unsigned int power_size, unsigned int power_seg_sz);
+unsigned int pblk_rb_calculate_size(unsigned int nr_entries);
+void *pblk_rb_entries_ref(struct pblk_rb *rb);
+int pblk_rb_may_write_user(struct pblk_rb *rb, struct bio *bio,
+			   unsigned int nr_entries, unsigned int *pos);
+int pblk_rb_may_write_gc(struct pblk_rb *rb, unsigned int nr_entries,
+			 unsigned int *pos);
+struct ppa_addr pblk_rb_write_entry(struct pblk_rb *rb, void *data,
+				    struct pblk_w_ctx w_ctx, unsigned int pos);
+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_list(struct pblk_rb *rb, struct bio *bio,
+				      struct list_head *list,
+				      unsigned int max);
+int pblk_rb_copy_to_bio(struct pblk_rb *rb, struct bio *bio, sector_t lba,
+			u64 pos, int bio_iter);
+unsigned int pblk_rb_read_commit(struct pblk_rb *rb, unsigned int entries);
+
+unsigned int pblk_rb_sync_init(struct pblk_rb *rb, unsigned long *flags);
+unsigned int pblk_rb_sync_advance(struct pblk_rb *rb, unsigned int nr_entries);
+struct pblk_rb_entry *pblk_rb_sync_scan_entry(struct pblk_rb *rb,
+					      struct ppa_addr *ppa);
+void pblk_rb_sync_end(struct pblk_rb *rb, unsigned long *flags);
+unsigned int pblk_rb_sync_point_count(struct pblk_rb *rb);
+
+unsigned int pblk_rb_read_count(struct pblk_rb *rb);
+unsigned int pblk_rb_wrap_pos(struct pblk_rb *rb, unsigned int pos);
+
+int pblk_rb_tear_down_check(struct pblk_rb *rb);
+int pblk_rb_pos_oob(struct pblk_rb *rb, u64 pos);
+void pblk_rb_data_free(struct pblk_rb *rb);
+ssize_t pblk_rb_sysfs(struct pblk_rb *rb, char *buf);
+
+#ifdef CONFIG_NVM_DEBUG
+ssize_t pblk_rb_sysfs_vb(struct pblk_rb *rb, char *buf);
+#endif
+
+/*
+ * pblk core
+ */
+struct nvm_rq *pblk_alloc_rqd(struct pblk *pblk, int rw);
+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);
+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);
+void pblk_log_read_err(struct pblk *pblk, struct nvm_rq *rqd);
+int pblk_submit_io(struct pblk *pblk, struct nvm_rq *rqd);
+struct pblk_line *pblk_line_get_first_data(struct pblk *pblk);
+struct pblk_line *pblk_line_get_next_data(struct pblk *pblk);
+struct pblk_line *pblk_line_replace_data(struct pblk *pblk);
+struct pblk_line *pblk_line_get_data(struct pblk *pblk);
+struct pblk_line *pblk_line_get_data_next(struct pblk *pblk);
+int pblk_line_secs_data(struct pblk *pblk);
+int pblk_line_is_full(struct pblk_line *line);
+void pblk_line_free(struct pblk *pblk, struct pblk_line *line);
+void pblk_line_close(struct work_struct *work);
+void pblk_line_mark_bb(struct work_struct *work);
+void pblk_line_run_ws(struct pblk *pblk, void *priv,
+		      void (*work)(struct work_struct *));
+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_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_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,
+		  unsigned long *lun_bitmap);
+void pblk_up_rq(struct pblk *pblk, struct ppa_addr *ppa_list, int nr_ppas,
+		unsigned long *lun_bitmap);
+void pblk_end_bio_sync(struct bio *bio);
+void pblk_pad_open_blks(struct pblk *pblk);
+struct pblk_block *pblk_get_blk(struct pblk *pblk, struct pblk_lun *rlun);
+int pblk_bio_add_pages(struct pblk *pblk, struct bio *bio, gfp_t flags,
+		       int nr_pages);
+void pblk_bio_free_pages(struct pblk *pblk, struct bio *bio, int off,
+			 int nr_pages);
+void pblk_update_map_cache(struct pblk *pblk, sector_t lba,
+			   struct ppa_addr ppa);
+void pblk_update_map_dev(struct pblk *pblk, sector_t lba,
+			struct ppa_addr new_line, struct ppa_addr entry_line);
+void pblk_update_map_gc(struct pblk *pblk, sector_t lba, struct ppa_addr ppa,
+			struct pblk_line *gc_line);
+void pblk_lookup_l2p_rand(struct pblk *pblk, struct ppa_addr *ppas,
+			  u64 *lba_list, int nr_secs);
+void pblk_lookup_l2p_seq(struct pblk *pblk, struct ppa_addr *ppas,
+			 sector_t blba, int nr_secs);
+
+#ifdef CONFIG_NVM_DEBUG
+void pblk_print_failed_rqd(struct pblk *pblk, struct nvm_rq *rqd, int error);
+int pblk_luns_configure(struct pblk *pblk);
+#endif
+
+/*
+ * pblk user I/O write path
+ */
+int pblk_write_to_cache(struct pblk *pblk, struct bio *bio,
+			unsigned long flags);
+int pblk_write_gc_to_cache(struct pblk *pblk, void *data, u64 *lba_list,
+			   unsigned int nr_entries, unsigned int nr_rec_entries,
+			   struct pblk_line *gc_line, unsigned long flags);
+
+/*
+ * pblk map
+ */
+int pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
+		      unsigned int sentry, unsigned long *lun_bitmap,
+		      unsigned int valid_secs, struct ppa_addr *erase_ppa);
+void pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
+		 unsigned long *lun_bitmap, unsigned int valid_secs,
+		 unsigned int off);
+
+/*
+ * pblk write thread
+ */
+int pblk_write_ts(void *data);
+void pblk_write_timer_fn(unsigned long data);
+
+/*
+ * pblk read path
+ */
+int pblk_submit_read(struct pblk *pblk, struct bio *bio);
+int pblk_submit_read_gc(struct pblk *pblk, u64 *lba_list, void *data,
+			unsigned int nr_secs, unsigned int *secs_to_gc,
+			struct pblk_line *line);
+/*
+ * pblk recovery
+ */
+void pblk_submit_rec(struct work_struct *work);
+u64 *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,
+			unsigned int comp);
+
+/*
+ * pblk gc
+ */
+#define PBLK_GC_TRIES 3
+
+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_queue(struct work_struct *work);
+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);
+
+/*
+ * pblk rate limiter
+ */
+void pblk_rl_init(struct pblk_rl *rl, int budget, spinlock_t *lock);
+void pblk_rl_free(struct pblk_rl *rl);
+int pblk_rl_gc_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);
+
+/*
+ * pblk sysfs
+ */
+int pblk_sysfs_init(struct gendisk *tdisk);
+void pblk_sysfs_exit(struct gendisk *tdisk);
+
+static inline void *pblk_malloc(size_t size, int type, gfp_t flags)
+{
+	if (type == PBLK_KMALLOC_META)
+		return kmalloc(size, flags);
+	return vmalloc(size);
+}
+
+static inline void pblk_mfree(void *ptr, int type)
+{
+	if (type == PBLK_KMALLOC_META)
+		kfree(ptr);
+	else
+		vfree(ptr);
+}
+
+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)
+{
+	return (emeta) + 1;
+}
+
+static inline u64 pblk_ppa_to_line(struct ppa_addr p)
+{
+	return p.g.blk;
+}
+
+/* A block within a line corresponds to the lun */
+static inline u64 pblk_ppa_to_pos(struct nvm_geo *geo, struct ppa_addr p)
+{
+	return p.g.lun * geo->nr_chnls + p.g.ch;
+}
+
+static inline u64 pblk_ppa_to_line_addr(struct pblk *pblk, struct ppa_addr p)
+{
+	u64 paddr;
+
+	paddr = 0;
+	paddr |= p.g.pg << pblk->ppaf.pg_offset;
+	paddr |= p.g.lun << pblk->ppaf.lun_offset;
+	paddr |= p.g.ch << pblk->ppaf.ch_offset;
+	paddr |= p.g.pl << pblk->ppaf.pln_offset;
+	paddr |= p.g.sec << pblk->ppaf.sec_offset;
+
+	return paddr;
+}
+
+static inline int nvm_addr_in_cache(struct ppa_addr ppa)
+{
+	return (ppa.ppa != ADDR_EMPTY && ppa.c.is_cached);
+}
+
+static inline u64 nvm_addr_to_cacheline(struct ppa_addr ppa)
+{
+#ifdef CONFIG_NVM_DEBUG
+	BUG_ON(ppa.ppa == ADDR_EMPTY);
+#endif
+	return ppa.c.line;
+}
+
+static inline void pblk_write_kick(struct pblk *pblk)
+{
+	wake_up_process(pblk->ts_writer);
+	mod_timer(&pblk->wtimer, jiffies + msecs_to_jiffies(1000));
+}
+
+static inline void pblk_ppa_set_empty(struct ppa_addr *ppa)
+{
+	ppa_set_empty(ppa);
+}
+
+/* Calculate the page offset of within a block from a generic address */
+static inline u64 pblk_gaddr_to_pg_offset(struct nvm_tgt_dev *dev,
+					  struct ppa_addr p)
+{
+	struct nvm_geo *geo = &dev->geo;
+
+	return (u64) (p.g.pg * geo->sec_per_pl) +
+				(p.g.pl * geo->sec_per_pg) + p.g.sec;
+}
+
+static inline struct ppa_addr pblk_cacheline_to_ppa(u64 addr)
+{
+	struct ppa_addr p;
+
+	p.c.line = (u64)addr;
+	p.c.is_cached = 1;
+
+	return p;
+}
+
+static inline struct ppa_addr pblk_dev_addr_to_ppa(u64 addr)
+{
+	struct ppa_addr gp;
+
+	gp.ppa = (u64)addr;
+	gp.c.is_cached = 0;
+
+	return gp;
+}
+
+static inline struct ppa_addr addr_to_ppa(u64 paddr, struct pblk_line *line)
+{
+	struct ppa_addr ppa;
+
+	ppa.ppa = 0;
+	ppa.g.blk = line->id;
+
+	return ppa;
+}
+
+static inline struct ppa_addr addr_to_gen_ppa(struct pblk *pblk, u64 paddr,
+					      u64 line_id)
+{
+	struct ppa_addr ppa;
+
+	ppa.ppa = 0;
+	ppa.g.blk = line_id;
+	ppa.g.pg = (paddr & pblk->ppaf.pg_mask) >> pblk->ppaf.pg_offset;
+	ppa.g.lun = (paddr & pblk->ppaf.lun_mask) >> pblk->ppaf.lun_offset;
+	ppa.g.ch = (paddr & pblk->ppaf.ch_mask) >> pblk->ppaf.ch_offset;
+	ppa.g.pl = (paddr & pblk->ppaf.pln_mask) >> pblk->ppaf.pln_offset;
+	ppa.g.sec = (paddr & pblk->ppaf.sec_mask) >> pblk->ppaf.sec_offset;
+
+	return ppa;
+}
+
+static inline u64 ppa_to_addr(struct ppa_addr ppa)
+{
+	return ppa.ppa;
+}
+
+static inline int pblk_set_progr_mode(struct pblk *pblk, int type)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	int flags;
+
+	flags = geo->plane_mode >> 1;
+
+	if (type == WRITE)
+		flags |= NVM_IO_SCRAMBLE_ENABLE;
+
+	return flags;
+}
+
+static inline int pblk_set_read_mode(struct pblk *pblk)
+{
+	return NVM_IO_SNGL_ACCESS | NVM_IO_SUSPEND | NVM_IO_SCRAMBLE_ENABLE;
+}
+
+static inline int pblk_boundary_checks(struct nvm_tgt_dev *tgt_dev,
+				       struct ppa_addr *ppas, int nr_ppas)
+{
+	struct nvm_geo *geo = &tgt_dev->geo;
+	struct ppa_addr *ppa;
+	int i;
+
+	for (i = 0; i < nr_ppas; i++) {
+		ppa = &ppas[i];
+
+		if (!ppa->c.is_cached &&
+				ppa->g.ch < geo->nr_chnls &&
+				ppa->g.lun < geo->nr_luns &&
+				ppa->g.pl < geo->nr_planes &&
+				ppa->g.blk < geo->blks_per_lun &&
+				ppa->g.pg < geo->pgs_per_blk &&
+				ppa->g.sec < geo->sec_per_pg)
+			continue;
+
+#ifdef CONFIG_NVM_DEBUG
+		if (ppa->c.is_cached)
+			pr_err("pblk: %d/%d oob(cacheline:%llu)\n",
+				i, nr_ppas, (u64)ppa->c.line);
+		else
+			pr_err("pblk: %d/%d oob(ch:%u,lun:%u,pl:%u,blk:%u,pg:%u,sec:%u\n)",
+				i, nr_ppas,
+				ppa->g.ch, ppa->g.lun, ppa->g.pl,
+				ppa->g.blk, ppa->g.pg, ppa->g.sec);
+#endif
+		return 1;
+	}
+	return 0;
+}
+
+static inline void print_ppa(struct ppa_addr *p, char *msg, int error)
+{
+	if (p->c.is_cached) {
+		pr_err("ppa: (%s: %x) cache line: %llu\n",
+				msg, error, (u64)p->c.line);
+	} else {
+		pr_err("ppa: (%s: %x):ch:%d,lun:%d,blk:%d,pg:%d,pl:%d,sec:%d\n",
+			msg, error,
+			p->g.ch, p->g.lun, p->g.blk,
+			p->g.pg, p->g.pl, p->g.sec);
+	}
+}
+
+static inline unsigned int pblk_get_bi_idx(struct bio *bio)
+{
+	return bio->bi_iter.bi_idx;
+}
+
+static inline sector_t pblk_get_lba(struct bio *bio)
+{
+	return bio->bi_iter.bi_sector / NR_PHY_IN_LOG;
+}
+
+static inline unsigned int pblk_get_secs(struct bio *bio)
+{
+	return  bio->bi_iter.bi_size / PBLK_EXPOSED_PAGE_SIZE;
+}
+
+static inline sector_t pblk_get_sector(sector_t lba)
+{
+	return lba * NR_PHY_IN_LOG;
+}
+
+static inline void inc_stat(struct pblk *pblk, unsigned long *stat, int interr)
+{
+	if (interr) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&pblk->lock, flags);
+		(*stat)++;
+		spin_unlock_irqrestore(&pblk->lock, flags);
+	} else {
+		spin_lock_irq(&pblk->lock);
+		(*stat)++;
+		spin_unlock_irq(&pblk->lock);
+	}
+}
+#endif /* PBLK_H_ */
-- 
2.7.4