diff --git a/src/kernel/linux/v4.19/drivers/lightnvm/Kconfig b/src/kernel/linux/v4.19/drivers/lightnvm/Kconfig
new file mode 100644
index 0000000..439bf90
--- /dev/null
+++ b/src/kernel/linux/v4.19/drivers/lightnvm/Kconfig
@@ -0,0 +1,41 @@
+#
+# Open-Channel SSD NVM configuration
+#
+
+menuconfig NVM
+	bool "Open-Channel SSD target support"
+	depends on BLOCK && PCI
+	select BLK_DEV_NVME
+	help
+	  Say Y here to get to enable Open-channel SSDs.
+
+	  Open-Channel SSDs implement a set of extension to SSDs, that
+	  exposes direct access to the underlying non-volatile memory.
+
+	  If you say N, all options in this submenu will be skipped and disabled
+	  only do this if you know what you are doing.
+
+if NVM
+
+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.
+
+if NVM_PBLK
+
+config NVM_PBLK_DEBUG
+	bool "PBlk Debug Support"
+	default n
+	help
+	  Enables debug support for pblk. This includes extra checks, more
+	  vocal error messages, and extra tracking fields in the pblk sysfs
+	  entries.
+
+endif # NVM_PBLK_DEBUG
+
+endif # NVM
diff --git a/src/kernel/linux/v4.19/drivers/lightnvm/Makefile b/src/kernel/linux/v4.19/drivers/lightnvm/Makefile
new file mode 100644
index 0000000..97d9d7c
--- /dev/null
+++ b/src/kernel/linux/v4.19/drivers/lightnvm/Makefile
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for Open-Channel SSDs.
+#
+
+obj-$(CONFIG_NVM)		:= core.o
+obj-$(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/src/kernel/linux/v4.19/drivers/lightnvm/core.c b/src/kernel/linux/v4.19/drivers/lightnvm/core.c
new file mode 100644
index 0000000..60aa7bc
--- /dev/null
+++ b/src/kernel/linux/v4.19/drivers/lightnvm/core.c
@@ -0,0 +1,1201 @@
+/*
+ * Copyright (C) 2015 IT University of Copenhagen. All rights reserved.
+ * Initial release: Matias Bjorling <m@bjorling.me>
+ *
+ * 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.
+ *
+ */
+
+#include <linux/list.h>
+#include <linux/types.h>
+#include <linux/sem.h>
+#include <linux/bitmap.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/miscdevice.h>
+#include <linux/lightnvm.h>
+#include <linux/sched/sysctl.h>
+
+static LIST_HEAD(nvm_tgt_types);
+static DECLARE_RWSEM(nvm_tgtt_lock);
+static LIST_HEAD(nvm_devices);
+static DECLARE_RWSEM(nvm_lock);
+
+/* Map between virtual and physical channel and lun */
+struct nvm_ch_map {
+	int ch_off;
+	int num_lun;
+	int *lun_offs;
+};
+
+struct nvm_dev_map {
+	struct nvm_ch_map *chnls;
+	int num_ch;
+};
+
+static struct nvm_target *nvm_find_target(struct nvm_dev *dev, const char *name)
+{
+	struct nvm_target *tgt;
+
+	list_for_each_entry(tgt, &dev->targets, list)
+		if (!strcmp(name, tgt->disk->disk_name))
+			return tgt;
+
+	return NULL;
+}
+
+static bool nvm_target_exists(const char *name)
+{
+	struct nvm_dev *dev;
+	struct nvm_target *tgt;
+	bool ret = false;
+
+	down_write(&nvm_lock);
+	list_for_each_entry(dev, &nvm_devices, devices) {
+		mutex_lock(&dev->mlock);
+		list_for_each_entry(tgt, &dev->targets, list) {
+			if (!strcmp(name, tgt->disk->disk_name)) {
+				ret = true;
+				mutex_unlock(&dev->mlock);
+				goto out;
+			}
+		}
+		mutex_unlock(&dev->mlock);
+	}
+
+out:
+	up_write(&nvm_lock);
+	return ret;
+}
+
+static int nvm_reserve_luns(struct nvm_dev *dev, int lun_begin, int lun_end)
+{
+	int i;
+
+	for (i = lun_begin; i <= lun_end; i++) {
+		if (test_and_set_bit(i, dev->lun_map)) {
+			pr_err("nvm: lun %d already allocated\n", i);
+			goto err;
+		}
+	}
+
+	return 0;
+err:
+	while (--i >= lun_begin)
+		clear_bit(i, dev->lun_map);
+
+	return -EBUSY;
+}
+
+static void nvm_release_luns_err(struct nvm_dev *dev, int lun_begin,
+				 int lun_end)
+{
+	int i;
+
+	for (i = lun_begin; i <= lun_end; i++)
+		WARN_ON(!test_and_clear_bit(i, dev->lun_map));
+}
+
+static void nvm_remove_tgt_dev(struct nvm_tgt_dev *tgt_dev, int clear)
+{
+	struct nvm_dev *dev = tgt_dev->parent;
+	struct nvm_dev_map *dev_map = tgt_dev->map;
+	int i, j;
+
+	for (i = 0; i < dev_map->num_ch; i++) {
+		struct nvm_ch_map *ch_map = &dev_map->chnls[i];
+		int *lun_offs = ch_map->lun_offs;
+		int ch = i + ch_map->ch_off;
+
+		if (clear) {
+			for (j = 0; j < ch_map->num_lun; j++) {
+				int lun = j + lun_offs[j];
+				int lunid = (ch * dev->geo.num_lun) + lun;
+
+				WARN_ON(!test_and_clear_bit(lunid,
+							dev->lun_map));
+			}
+		}
+
+		kfree(ch_map->lun_offs);
+	}
+
+	kfree(dev_map->chnls);
+	kfree(dev_map);
+
+	kfree(tgt_dev->luns);
+	kfree(tgt_dev);
+}
+
+static struct nvm_tgt_dev *nvm_create_tgt_dev(struct nvm_dev *dev,
+					      u16 lun_begin, u16 lun_end,
+					      u16 op)
+{
+	struct nvm_tgt_dev *tgt_dev = NULL;
+	struct nvm_dev_map *dev_rmap = dev->rmap;
+	struct nvm_dev_map *dev_map;
+	struct ppa_addr *luns;
+	int num_lun = lun_end - lun_begin + 1;
+	int luns_left = num_lun;
+	int num_ch = num_lun / dev->geo.num_lun;
+	int num_ch_mod = num_lun % dev->geo.num_lun;
+	int bch = lun_begin / dev->geo.num_lun;
+	int blun = lun_begin % dev->geo.num_lun;
+	int lunid = 0;
+	int lun_balanced = 1;
+	int sec_per_lun, prev_num_lun;
+	int i, j;
+
+	num_ch = (num_ch_mod == 0) ? num_ch : num_ch + 1;
+
+	dev_map = kmalloc(sizeof(struct nvm_dev_map), GFP_KERNEL);
+	if (!dev_map)
+		goto err_dev;
+
+	dev_map->chnls = kcalloc(num_ch, sizeof(struct nvm_ch_map), GFP_KERNEL);
+	if (!dev_map->chnls)
+		goto err_chnls;
+
+	luns = kcalloc(num_lun, sizeof(struct ppa_addr), GFP_KERNEL);
+	if (!luns)
+		goto err_luns;
+
+	prev_num_lun = (luns_left > dev->geo.num_lun) ?
+					dev->geo.num_lun : luns_left;
+	for (i = 0; i < num_ch; i++) {
+		struct nvm_ch_map *ch_rmap = &dev_rmap->chnls[i + bch];
+		int *lun_roffs = ch_rmap->lun_offs;
+		struct nvm_ch_map *ch_map = &dev_map->chnls[i];
+		int *lun_offs;
+		int luns_in_chnl = (luns_left > dev->geo.num_lun) ?
+					dev->geo.num_lun : luns_left;
+
+		if (lun_balanced && prev_num_lun != luns_in_chnl)
+			lun_balanced = 0;
+
+		ch_map->ch_off = ch_rmap->ch_off = bch;
+		ch_map->num_lun = luns_in_chnl;
+
+		lun_offs = kcalloc(luns_in_chnl, sizeof(int), GFP_KERNEL);
+		if (!lun_offs)
+			goto err_ch;
+
+		for (j = 0; j < luns_in_chnl; j++) {
+			luns[lunid].ppa = 0;
+			luns[lunid].a.ch = i;
+			luns[lunid++].a.lun = j;
+
+			lun_offs[j] = blun;
+			lun_roffs[j + blun] = blun;
+		}
+
+		ch_map->lun_offs = lun_offs;
+
+		/* when starting a new channel, lun offset is reset */
+		blun = 0;
+		luns_left -= luns_in_chnl;
+	}
+
+	dev_map->num_ch = num_ch;
+
+	tgt_dev = kmalloc(sizeof(struct nvm_tgt_dev), GFP_KERNEL);
+	if (!tgt_dev)
+		goto err_ch;
+
+	/* Inherit device geometry from parent */
+	memcpy(&tgt_dev->geo, &dev->geo, sizeof(struct nvm_geo));
+
+	/* Target device only owns a portion of the physical device */
+	tgt_dev->geo.num_ch = num_ch;
+	tgt_dev->geo.num_lun = (lun_balanced) ? prev_num_lun : -1;
+	tgt_dev->geo.all_luns = num_lun;
+	tgt_dev->geo.all_chunks = num_lun * dev->geo.num_chk;
+
+	tgt_dev->geo.op = op;
+
+	sec_per_lun = dev->geo.clba * dev->geo.num_chk;
+	tgt_dev->geo.total_secs = num_lun * sec_per_lun;
+
+	tgt_dev->q = dev->q;
+	tgt_dev->map = dev_map;
+	tgt_dev->luns = luns;
+	tgt_dev->parent = dev;
+
+	return tgt_dev;
+err_ch:
+	while (--i >= 0)
+		kfree(dev_map->chnls[i].lun_offs);
+	kfree(luns);
+err_luns:
+	kfree(dev_map->chnls);
+err_chnls:
+	kfree(dev_map);
+err_dev:
+	return tgt_dev;
+}
+
+static const struct block_device_operations nvm_fops = {
+	.owner		= THIS_MODULE,
+};
+
+static struct nvm_tgt_type *__nvm_find_target_type(const char *name)
+{
+	struct nvm_tgt_type *tt;
+
+	list_for_each_entry(tt, &nvm_tgt_types, list)
+		if (!strcmp(name, tt->name))
+			return tt;
+
+	return NULL;
+}
+
+static struct nvm_tgt_type *nvm_find_target_type(const char *name)
+{
+	struct nvm_tgt_type *tt;
+
+	down_write(&nvm_tgtt_lock);
+	tt = __nvm_find_target_type(name);
+	up_write(&nvm_tgtt_lock);
+
+	return tt;
+}
+
+static int nvm_config_check_luns(struct nvm_geo *geo, int lun_begin,
+				 int lun_end)
+{
+	if (lun_begin > lun_end || lun_end >= geo->all_luns) {
+		pr_err("nvm: lun out of bound (%u:%u > %u)\n",
+			lun_begin, lun_end, geo->all_luns - 1);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int __nvm_config_simple(struct nvm_dev *dev,
+			       struct nvm_ioctl_create_simple *s)
+{
+	struct nvm_geo *geo = &dev->geo;
+
+	if (s->lun_begin == -1 && s->lun_end == -1) {
+		s->lun_begin = 0;
+		s->lun_end = geo->all_luns - 1;
+	}
+
+	return nvm_config_check_luns(geo, s->lun_begin, s->lun_end);
+}
+
+static int __nvm_config_extended(struct nvm_dev *dev,
+				 struct nvm_ioctl_create_extended *e)
+{
+	if (e->lun_begin == 0xFFFF && e->lun_end == 0xFFFF) {
+		e->lun_begin = 0;
+		e->lun_end = dev->geo.all_luns - 1;
+	}
+
+	/* op not set falls into target's default */
+	if (e->op == 0xFFFF) {
+		e->op = NVM_TARGET_DEFAULT_OP;
+	} else if (e->op < NVM_TARGET_MIN_OP || e->op > NVM_TARGET_MAX_OP) {
+		pr_err("nvm: invalid over provisioning value\n");
+		return -EINVAL;
+	}
+
+	return nvm_config_check_luns(&dev->geo, e->lun_begin, e->lun_end);
+}
+
+static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
+{
+	struct nvm_ioctl_create_extended e;
+	struct request_queue *tqueue;
+	struct gendisk *tdisk;
+	struct nvm_tgt_type *tt;
+	struct nvm_target *t;
+	struct nvm_tgt_dev *tgt_dev;
+	void *targetdata;
+	int ret;
+
+	switch (create->conf.type) {
+	case NVM_CONFIG_TYPE_SIMPLE:
+		ret = __nvm_config_simple(dev, &create->conf.s);
+		if (ret)
+			return ret;
+
+		e.lun_begin = create->conf.s.lun_begin;
+		e.lun_end = create->conf.s.lun_end;
+		e.op = NVM_TARGET_DEFAULT_OP;
+		break;
+	case NVM_CONFIG_TYPE_EXTENDED:
+		ret = __nvm_config_extended(dev, &create->conf.e);
+		if (ret)
+			return ret;
+
+		e = create->conf.e;
+		break;
+	default:
+		pr_err("nvm: config type not valid\n");
+		return -EINVAL;
+	}
+
+	tt = nvm_find_target_type(create->tgttype);
+	if (!tt) {
+		pr_err("nvm: target type %s not found\n", create->tgttype);
+		return -EINVAL;
+	}
+
+	if (nvm_target_exists(create->tgtname)) {
+		pr_err("nvm: target name already exists (%s)\n",
+							create->tgtname);
+		return -EINVAL;
+	}
+
+	ret = nvm_reserve_luns(dev, e.lun_begin, e.lun_end);
+	if (ret)
+		return ret;
+
+	t = kmalloc(sizeof(struct nvm_target), GFP_KERNEL);
+	if (!t) {
+		ret = -ENOMEM;
+		goto err_reserve;
+	}
+
+	tgt_dev = nvm_create_tgt_dev(dev, e.lun_begin, e.lun_end, e.op);
+	if (!tgt_dev) {
+		pr_err("nvm: could not create target device\n");
+		ret = -ENOMEM;
+		goto err_t;
+	}
+
+	tdisk = alloc_disk(0);
+	if (!tdisk) {
+		ret = -ENOMEM;
+		goto err_dev;
+	}
+
+	tqueue = blk_alloc_queue_node(GFP_KERNEL, dev->q->node, NULL);
+	if (!tqueue) {
+		ret = -ENOMEM;
+		goto err_disk;
+	}
+	blk_queue_make_request(tqueue, tt->make_rq);
+
+	strlcpy(tdisk->disk_name, create->tgtname, sizeof(tdisk->disk_name));
+	tdisk->flags = GENHD_FL_EXT_DEVT;
+	tdisk->major = 0;
+	tdisk->first_minor = 0;
+	tdisk->fops = &nvm_fops;
+	tdisk->queue = tqueue;
+
+	targetdata = tt->init(tgt_dev, tdisk, create->flags);
+	if (IS_ERR(targetdata)) {
+		ret = PTR_ERR(targetdata);
+		goto err_init;
+	}
+
+	tdisk->private_data = targetdata;
+	tqueue->queuedata = targetdata;
+
+	blk_queue_max_hw_sectors(tqueue,
+			(dev->geo.csecs >> 9) * NVM_MAX_VLBA);
+
+	set_capacity(tdisk, tt->capacity(targetdata));
+	add_disk(tdisk);
+
+	if (tt->sysfs_init && tt->sysfs_init(tdisk)) {
+		ret = -ENOMEM;
+		goto err_sysfs;
+	}
+
+	t->type = tt;
+	t->disk = tdisk;
+	t->dev = tgt_dev;
+
+	mutex_lock(&dev->mlock);
+	list_add_tail(&t->list, &dev->targets);
+	mutex_unlock(&dev->mlock);
+
+	__module_get(tt->owner);
+
+	return 0;
+err_sysfs:
+	if (tt->exit)
+		tt->exit(targetdata, true);
+err_init:
+	blk_cleanup_queue(tqueue);
+	tdisk->queue = NULL;
+err_disk:
+	put_disk(tdisk);
+err_dev:
+	nvm_remove_tgt_dev(tgt_dev, 0);
+err_t:
+	kfree(t);
+err_reserve:
+	nvm_release_luns_err(dev, e.lun_begin, e.lun_end);
+	return ret;
+}
+
+static void __nvm_remove_target(struct nvm_target *t, bool graceful)
+{
+	struct nvm_tgt_type *tt = t->type;
+	struct gendisk *tdisk = t->disk;
+	struct request_queue *q = tdisk->queue;
+
+	del_gendisk(tdisk);
+	blk_cleanup_queue(q);
+
+	if (tt->sysfs_exit)
+		tt->sysfs_exit(tdisk);
+
+	if (tt->exit)
+		tt->exit(tdisk->private_data, graceful);
+
+	nvm_remove_tgt_dev(t->dev, 1);
+	put_disk(tdisk);
+	module_put(t->type->owner);
+
+	list_del(&t->list);
+	kfree(t);
+}
+
+/**
+ * nvm_remove_tgt - Removes a target from the media manager
+ * @dev:	device
+ * @remove:	ioctl structure with target name to remove.
+ *
+ * Returns:
+ * 0: on success
+ * 1: on not found
+ * <0: on error
+ */
+static int nvm_remove_tgt(struct nvm_dev *dev, struct nvm_ioctl_remove *remove)
+{
+	struct nvm_target *t;
+
+	mutex_lock(&dev->mlock);
+	t = nvm_find_target(dev, remove->tgtname);
+	if (!t) {
+		mutex_unlock(&dev->mlock);
+		return 1;
+	}
+	__nvm_remove_target(t, true);
+	mutex_unlock(&dev->mlock);
+
+	return 0;
+}
+
+static int nvm_register_map(struct nvm_dev *dev)
+{
+	struct nvm_dev_map *rmap;
+	int i, j;
+
+	rmap = kmalloc(sizeof(struct nvm_dev_map), GFP_KERNEL);
+	if (!rmap)
+		goto err_rmap;
+
+	rmap->chnls = kcalloc(dev->geo.num_ch, sizeof(struct nvm_ch_map),
+								GFP_KERNEL);
+	if (!rmap->chnls)
+		goto err_chnls;
+
+	for (i = 0; i < dev->geo.num_ch; i++) {
+		struct nvm_ch_map *ch_rmap;
+		int *lun_roffs;
+		int luns_in_chnl = dev->geo.num_lun;
+
+		ch_rmap = &rmap->chnls[i];
+
+		ch_rmap->ch_off = -1;
+		ch_rmap->num_lun = luns_in_chnl;
+
+		lun_roffs = kcalloc(luns_in_chnl, sizeof(int), GFP_KERNEL);
+		if (!lun_roffs)
+			goto err_ch;
+
+		for (j = 0; j < luns_in_chnl; j++)
+			lun_roffs[j] = -1;
+
+		ch_rmap->lun_offs = lun_roffs;
+	}
+
+	dev->rmap = rmap;
+
+	return 0;
+err_ch:
+	while (--i >= 0)
+		kfree(rmap->chnls[i].lun_offs);
+err_chnls:
+	kfree(rmap);
+err_rmap:
+	return -ENOMEM;
+}
+
+static void nvm_unregister_map(struct nvm_dev *dev)
+{
+	struct nvm_dev_map *rmap = dev->rmap;
+	int i;
+
+	for (i = 0; i < dev->geo.num_ch; i++)
+		kfree(rmap->chnls[i].lun_offs);
+
+	kfree(rmap->chnls);
+	kfree(rmap);
+}
+
+static void nvm_map_to_dev(struct nvm_tgt_dev *tgt_dev, struct ppa_addr *p)
+{
+	struct nvm_dev_map *dev_map = tgt_dev->map;
+	struct nvm_ch_map *ch_map = &dev_map->chnls[p->a.ch];
+	int lun_off = ch_map->lun_offs[p->a.lun];
+
+	p->a.ch += ch_map->ch_off;
+	p->a.lun += lun_off;
+}
+
+static void nvm_map_to_tgt(struct nvm_tgt_dev *tgt_dev, struct ppa_addr *p)
+{
+	struct nvm_dev *dev = tgt_dev->parent;
+	struct nvm_dev_map *dev_rmap = dev->rmap;
+	struct nvm_ch_map *ch_rmap = &dev_rmap->chnls[p->a.ch];
+	int lun_roff = ch_rmap->lun_offs[p->a.lun];
+
+	p->a.ch -= ch_rmap->ch_off;
+	p->a.lun -= lun_roff;
+}
+
+static void nvm_ppa_tgt_to_dev(struct nvm_tgt_dev *tgt_dev,
+				struct ppa_addr *ppa_list, int nr_ppas)
+{
+	int i;
+
+	for (i = 0; i < nr_ppas; i++) {
+		nvm_map_to_dev(tgt_dev, &ppa_list[i]);
+		ppa_list[i] = generic_to_dev_addr(tgt_dev->parent, ppa_list[i]);
+	}
+}
+
+static void nvm_ppa_dev_to_tgt(struct nvm_tgt_dev *tgt_dev,
+				struct ppa_addr *ppa_list, int nr_ppas)
+{
+	int i;
+
+	for (i = 0; i < nr_ppas; i++) {
+		ppa_list[i] = dev_to_generic_addr(tgt_dev->parent, ppa_list[i]);
+		nvm_map_to_tgt(tgt_dev, &ppa_list[i]);
+	}
+}
+
+static void nvm_rq_tgt_to_dev(struct nvm_tgt_dev *tgt_dev, struct nvm_rq *rqd)
+{
+	if (rqd->nr_ppas == 1) {
+		nvm_ppa_tgt_to_dev(tgt_dev, &rqd->ppa_addr, 1);
+		return;
+	}
+
+	nvm_ppa_tgt_to_dev(tgt_dev, rqd->ppa_list, rqd->nr_ppas);
+}
+
+static void nvm_rq_dev_to_tgt(struct nvm_tgt_dev *tgt_dev, struct nvm_rq *rqd)
+{
+	if (rqd->nr_ppas == 1) {
+		nvm_ppa_dev_to_tgt(tgt_dev, &rqd->ppa_addr, 1);
+		return;
+	}
+
+	nvm_ppa_dev_to_tgt(tgt_dev, rqd->ppa_list, rqd->nr_ppas);
+}
+
+int nvm_register_tgt_type(struct nvm_tgt_type *tt)
+{
+	int ret = 0;
+
+	down_write(&nvm_tgtt_lock);
+	if (__nvm_find_target_type(tt->name))
+		ret = -EEXIST;
+	else
+		list_add(&tt->list, &nvm_tgt_types);
+	up_write(&nvm_tgtt_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(nvm_register_tgt_type);
+
+void nvm_unregister_tgt_type(struct nvm_tgt_type *tt)
+{
+	if (!tt)
+		return;
+
+	down_write(&nvm_tgtt_lock);
+	list_del(&tt->list);
+	up_write(&nvm_tgtt_lock);
+}
+EXPORT_SYMBOL(nvm_unregister_tgt_type);
+
+void *nvm_dev_dma_alloc(struct nvm_dev *dev, gfp_t mem_flags,
+							dma_addr_t *dma_handler)
+{
+	return dev->ops->dev_dma_alloc(dev, dev->dma_pool, mem_flags,
+								dma_handler);
+}
+EXPORT_SYMBOL(nvm_dev_dma_alloc);
+
+void nvm_dev_dma_free(struct nvm_dev *dev, void *addr, dma_addr_t dma_handler)
+{
+	dev->ops->dev_dma_free(dev->dma_pool, addr, dma_handler);
+}
+EXPORT_SYMBOL(nvm_dev_dma_free);
+
+static struct nvm_dev *nvm_find_nvm_dev(const char *name)
+{
+	struct nvm_dev *dev;
+
+	list_for_each_entry(dev, &nvm_devices, devices)
+		if (!strcmp(name, dev->name))
+			return dev;
+
+	return NULL;
+}
+
+static int nvm_set_rqd_ppalist(struct nvm_tgt_dev *tgt_dev, struct nvm_rq *rqd,
+			const struct ppa_addr *ppas, int nr_ppas)
+{
+	struct nvm_dev *dev = tgt_dev->parent;
+	struct nvm_geo *geo = &tgt_dev->geo;
+	int i, plane_cnt, pl_idx;
+	struct ppa_addr ppa;
+
+	if (geo->pln_mode == NVM_PLANE_SINGLE && nr_ppas == 1) {
+		rqd->nr_ppas = nr_ppas;
+		rqd->ppa_addr = ppas[0];
+
+		return 0;
+	}
+
+	rqd->nr_ppas = nr_ppas;
+	rqd->ppa_list = nvm_dev_dma_alloc(dev, GFP_KERNEL, &rqd->dma_ppa_list);
+	if (!rqd->ppa_list) {
+		pr_err("nvm: failed to allocate dma memory\n");
+		return -ENOMEM;
+	}
+
+	plane_cnt = geo->pln_mode;
+	rqd->nr_ppas *= plane_cnt;
+
+	for (i = 0; i < nr_ppas; i++) {
+		for (pl_idx = 0; pl_idx < plane_cnt; pl_idx++) {
+			ppa = ppas[i];
+			ppa.g.pl = pl_idx;
+			rqd->ppa_list[(pl_idx * nr_ppas) + i] = ppa;
+		}
+	}
+
+	return 0;
+}
+
+static void nvm_free_rqd_ppalist(struct nvm_tgt_dev *tgt_dev,
+			struct nvm_rq *rqd)
+{
+	if (!rqd->ppa_list)
+		return;
+
+	nvm_dev_dma_free(tgt_dev->parent, rqd->ppa_list, rqd->dma_ppa_list);
+}
+
+int nvm_get_chunk_meta(struct nvm_tgt_dev *tgt_dev, struct nvm_chk_meta *meta,
+		struct ppa_addr ppa, int nchks)
+{
+	struct nvm_dev *dev = tgt_dev->parent;
+
+	nvm_ppa_tgt_to_dev(tgt_dev, &ppa, 1);
+
+	return dev->ops->get_chk_meta(tgt_dev->parent, meta,
+						(sector_t)ppa.ppa, nchks);
+}
+EXPORT_SYMBOL(nvm_get_chunk_meta);
+
+int nvm_set_tgt_bb_tbl(struct nvm_tgt_dev *tgt_dev, struct ppa_addr *ppas,
+		       int nr_ppas, int type)
+{
+	struct nvm_dev *dev = tgt_dev->parent;
+	struct nvm_rq rqd;
+	int ret;
+
+	if (nr_ppas > NVM_MAX_VLBA) {
+		pr_err("nvm: unable to update all blocks atomically\n");
+		return -EINVAL;
+	}
+
+	memset(&rqd, 0, sizeof(struct nvm_rq));
+
+	nvm_set_rqd_ppalist(tgt_dev, &rqd, ppas, nr_ppas);
+	nvm_rq_tgt_to_dev(tgt_dev, &rqd);
+
+	ret = dev->ops->set_bb_tbl(dev, &rqd.ppa_addr, rqd.nr_ppas, type);
+	nvm_free_rqd_ppalist(tgt_dev, &rqd);
+	if (ret) {
+		pr_err("nvm: failed bb mark\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(nvm_set_tgt_bb_tbl);
+
+int nvm_submit_io(struct nvm_tgt_dev *tgt_dev, struct nvm_rq *rqd)
+{
+	struct nvm_dev *dev = tgt_dev->parent;
+	int ret;
+
+	if (!dev->ops->submit_io)
+		return -ENODEV;
+
+	nvm_rq_tgt_to_dev(tgt_dev, rqd);
+
+	rqd->dev = tgt_dev;
+
+	/* In case of error, fail with right address format */
+	ret = dev->ops->submit_io(dev, rqd);
+	if (ret)
+		nvm_rq_dev_to_tgt(tgt_dev, rqd);
+	return ret;
+}
+EXPORT_SYMBOL(nvm_submit_io);
+
+int nvm_submit_io_sync(struct nvm_tgt_dev *tgt_dev, struct nvm_rq *rqd)
+{
+	struct nvm_dev *dev = tgt_dev->parent;
+	int ret;
+
+	if (!dev->ops->submit_io_sync)
+		return -ENODEV;
+
+	nvm_rq_tgt_to_dev(tgt_dev, rqd);
+
+	rqd->dev = tgt_dev;
+
+	/* In case of error, fail with right address format */
+	ret = dev->ops->submit_io_sync(dev, rqd);
+	nvm_rq_dev_to_tgt(tgt_dev, rqd);
+
+	return ret;
+}
+EXPORT_SYMBOL(nvm_submit_io_sync);
+
+void nvm_end_io(struct nvm_rq *rqd)
+{
+	struct nvm_tgt_dev *tgt_dev = rqd->dev;
+
+	/* Convert address space */
+	if (tgt_dev)
+		nvm_rq_dev_to_tgt(tgt_dev, rqd);
+
+	if (rqd->end_io)
+		rqd->end_io(rqd);
+}
+EXPORT_SYMBOL(nvm_end_io);
+
+/*
+ * folds a bad block list from its plane representation to its virtual
+ * block representation. The fold is done in place and reduced size is
+ * returned.
+ *
+ * If any of the planes status are bad or grown bad block, the virtual block
+ * is marked bad. If not bad, the first plane state acts as the block state.
+ */
+int nvm_bb_tbl_fold(struct nvm_dev *dev, u8 *blks, int nr_blks)
+{
+	struct nvm_geo *geo = &dev->geo;
+	int blk, offset, pl, blktype;
+
+	if (nr_blks != geo->num_chk * geo->pln_mode)
+		return -EINVAL;
+
+	for (blk = 0; blk < geo->num_chk; blk++) {
+		offset = blk * geo->pln_mode;
+		blktype = blks[offset];
+
+		/* Bad blocks on any planes take precedence over other types */
+		for (pl = 0; pl < geo->pln_mode; pl++) {
+			if (blks[offset + pl] &
+					(NVM_BLK_T_BAD|NVM_BLK_T_GRWN_BAD)) {
+				blktype = blks[offset + pl];
+				break;
+			}
+		}
+
+		blks[blk] = blktype;
+	}
+
+	return geo->num_chk;
+}
+EXPORT_SYMBOL(nvm_bb_tbl_fold);
+
+int nvm_get_tgt_bb_tbl(struct nvm_tgt_dev *tgt_dev, struct ppa_addr ppa,
+		       u8 *blks)
+{
+	struct nvm_dev *dev = tgt_dev->parent;
+
+	nvm_ppa_tgt_to_dev(tgt_dev, &ppa, 1);
+
+	return dev->ops->get_bb_tbl(dev, ppa, blks);
+}
+EXPORT_SYMBOL(nvm_get_tgt_bb_tbl);
+
+static int nvm_core_init(struct nvm_dev *dev)
+{
+	struct nvm_geo *geo = &dev->geo;
+	int ret;
+
+	dev->lun_map = kcalloc(BITS_TO_LONGS(geo->all_luns),
+					sizeof(unsigned long), GFP_KERNEL);
+	if (!dev->lun_map)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&dev->area_list);
+	INIT_LIST_HEAD(&dev->targets);
+	mutex_init(&dev->mlock);
+	spin_lock_init(&dev->lock);
+
+	ret = nvm_register_map(dev);
+	if (ret)
+		goto err_fmtype;
+
+	return 0;
+err_fmtype:
+	kfree(dev->lun_map);
+	return ret;
+}
+
+static void nvm_free(struct nvm_dev *dev)
+{
+	if (!dev)
+		return;
+
+	if (dev->dma_pool)
+		dev->ops->destroy_dma_pool(dev->dma_pool);
+
+	nvm_unregister_map(dev);
+	kfree(dev->lun_map);
+	kfree(dev);
+}
+
+static int nvm_init(struct nvm_dev *dev)
+{
+	struct nvm_geo *geo = &dev->geo;
+	int ret = -EINVAL;
+
+	if (dev->ops->identity(dev)) {
+		pr_err("nvm: device could not be identified\n");
+		goto err;
+	}
+
+	pr_debug("nvm: ver:%u.%u nvm_vendor:%x\n",
+				geo->major_ver_id, geo->minor_ver_id,
+				geo->vmnt);
+
+	ret = nvm_core_init(dev);
+	if (ret) {
+		pr_err("nvm: could not initialize core structures.\n");
+		goto err;
+	}
+
+	pr_info("nvm: registered %s [%u/%u/%u/%u/%u]\n",
+			dev->name, dev->geo.ws_min, dev->geo.ws_opt,
+			dev->geo.num_chk, dev->geo.all_luns,
+			dev->geo.num_ch);
+	return 0;
+err:
+	pr_err("nvm: failed to initialize nvm\n");
+	return ret;
+}
+
+struct nvm_dev *nvm_alloc_dev(int node)
+{
+	return kzalloc_node(sizeof(struct nvm_dev), GFP_KERNEL, node);
+}
+EXPORT_SYMBOL(nvm_alloc_dev);
+
+int nvm_register(struct nvm_dev *dev)
+{
+	int ret;
+
+	if (!dev->q || !dev->ops)
+		return -EINVAL;
+
+	dev->dma_pool = dev->ops->create_dma_pool(dev, "ppalist");
+	if (!dev->dma_pool) {
+		pr_err("nvm: could not create dma pool\n");
+		return -ENOMEM;
+	}
+
+	ret = nvm_init(dev);
+	if (ret)
+		goto err_init;
+
+	/* register device with a supported media manager */
+	down_write(&nvm_lock);
+	list_add(&dev->devices, &nvm_devices);
+	up_write(&nvm_lock);
+
+	return 0;
+err_init:
+	dev->ops->destroy_dma_pool(dev->dma_pool);
+	return ret;
+}
+EXPORT_SYMBOL(nvm_register);
+
+void nvm_unregister(struct nvm_dev *dev)
+{
+	struct nvm_target *t, *tmp;
+
+	mutex_lock(&dev->mlock);
+	list_for_each_entry_safe(t, tmp, &dev->targets, list) {
+		if (t->dev->parent != dev)
+			continue;
+		__nvm_remove_target(t, false);
+	}
+	mutex_unlock(&dev->mlock);
+
+	down_write(&nvm_lock);
+	list_del(&dev->devices);
+	up_write(&nvm_lock);
+
+	nvm_free(dev);
+}
+EXPORT_SYMBOL(nvm_unregister);
+
+static int __nvm_configure_create(struct nvm_ioctl_create *create)
+{
+	struct nvm_dev *dev;
+
+	down_write(&nvm_lock);
+	dev = nvm_find_nvm_dev(create->dev);
+	up_write(&nvm_lock);
+
+	if (!dev) {
+		pr_err("nvm: device not found\n");
+		return -EINVAL;
+	}
+
+	return nvm_create_tgt(dev, create);
+}
+
+static long nvm_ioctl_info(struct file *file, void __user *arg)
+{
+	struct nvm_ioctl_info *info;
+	struct nvm_tgt_type *tt;
+	int tgt_iter = 0;
+
+	info = memdup_user(arg, sizeof(struct nvm_ioctl_info));
+	if (IS_ERR(info))
+		return -EFAULT;
+
+	info->version[0] = NVM_VERSION_MAJOR;
+	info->version[1] = NVM_VERSION_MINOR;
+	info->version[2] = NVM_VERSION_PATCH;
+
+	down_write(&nvm_tgtt_lock);
+	list_for_each_entry(tt, &nvm_tgt_types, list) {
+		struct nvm_ioctl_info_tgt *tgt = &info->tgts[tgt_iter];
+
+		tgt->version[0] = tt->version[0];
+		tgt->version[1] = tt->version[1];
+		tgt->version[2] = tt->version[2];
+		strncpy(tgt->tgtname, tt->name, NVM_TTYPE_NAME_MAX);
+
+		tgt_iter++;
+	}
+
+	info->tgtsize = tgt_iter;
+	up_write(&nvm_tgtt_lock);
+
+	if (copy_to_user(arg, info, sizeof(struct nvm_ioctl_info))) {
+		kfree(info);
+		return -EFAULT;
+	}
+
+	kfree(info);
+	return 0;
+}
+
+static long nvm_ioctl_get_devices(struct file *file, void __user *arg)
+{
+	struct nvm_ioctl_get_devices *devices;
+	struct nvm_dev *dev;
+	int i = 0;
+
+	devices = kzalloc(sizeof(struct nvm_ioctl_get_devices), GFP_KERNEL);
+	if (!devices)
+		return -ENOMEM;
+
+	down_write(&nvm_lock);
+	list_for_each_entry(dev, &nvm_devices, devices) {
+		struct nvm_ioctl_device_info *info = &devices->info[i];
+
+		strlcpy(info->devname, dev->name, sizeof(info->devname));
+
+		/* kept for compatibility */
+		info->bmversion[0] = 1;
+		info->bmversion[1] = 0;
+		info->bmversion[2] = 0;
+		strlcpy(info->bmname, "gennvm", sizeof(info->bmname));
+		i++;
+
+		if (i > 31) {
+			pr_err("nvm: max 31 devices can be reported.\n");
+			break;
+		}
+	}
+	up_write(&nvm_lock);
+
+	devices->nr_devices = i;
+
+	if (copy_to_user(arg, devices,
+			 sizeof(struct nvm_ioctl_get_devices))) {
+		kfree(devices);
+		return -EFAULT;
+	}
+
+	kfree(devices);
+	return 0;
+}
+
+static long nvm_ioctl_dev_create(struct file *file, void __user *arg)
+{
+	struct nvm_ioctl_create create;
+
+	if (copy_from_user(&create, arg, sizeof(struct nvm_ioctl_create)))
+		return -EFAULT;
+
+	if (create.conf.type == NVM_CONFIG_TYPE_EXTENDED &&
+	    create.conf.e.rsv != 0) {
+		pr_err("nvm: reserved config field in use\n");
+		return -EINVAL;
+	}
+
+	create.dev[DISK_NAME_LEN - 1] = '\0';
+	create.tgttype[NVM_TTYPE_NAME_MAX - 1] = '\0';
+	create.tgtname[DISK_NAME_LEN - 1] = '\0';
+
+	if (create.flags != 0) {
+		__u32 flags = create.flags;
+
+		/* Check for valid flags */
+		if (flags & NVM_TARGET_FACTORY)
+			flags &= ~NVM_TARGET_FACTORY;
+
+		if (flags) {
+			pr_err("nvm: flag not supported\n");
+			return -EINVAL;
+		}
+	}
+
+	return __nvm_configure_create(&create);
+}
+
+static long nvm_ioctl_dev_remove(struct file *file, void __user *arg)
+{
+	struct nvm_ioctl_remove remove;
+	struct nvm_dev *dev;
+	int ret = 0;
+
+	if (copy_from_user(&remove, arg, sizeof(struct nvm_ioctl_remove)))
+		return -EFAULT;
+
+	remove.tgtname[DISK_NAME_LEN - 1] = '\0';
+
+	if (remove.flags != 0) {
+		pr_err("nvm: no flags supported\n");
+		return -EINVAL;
+	}
+
+	list_for_each_entry(dev, &nvm_devices, devices) {
+		ret = nvm_remove_tgt(dev, &remove);
+		if (!ret)
+			break;
+	}
+
+	return ret;
+}
+
+/* kept for compatibility reasons */
+static long nvm_ioctl_dev_init(struct file *file, void __user *arg)
+{
+	struct nvm_ioctl_dev_init init;
+
+	if (copy_from_user(&init, arg, sizeof(struct nvm_ioctl_dev_init)))
+		return -EFAULT;
+
+	if (init.flags != 0) {
+		pr_err("nvm: no flags supported\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/* Kept for compatibility reasons */
+static long nvm_ioctl_dev_factory(struct file *file, void __user *arg)
+{
+	struct nvm_ioctl_dev_factory fact;
+
+	if (copy_from_user(&fact, arg, sizeof(struct nvm_ioctl_dev_factory)))
+		return -EFAULT;
+
+	fact.dev[DISK_NAME_LEN - 1] = '\0';
+
+	if (fact.flags & ~(NVM_FACTORY_NR_BITS - 1))
+		return -EINVAL;
+
+	return 0;
+}
+
+static long nvm_ctl_ioctl(struct file *file, uint cmd, unsigned long arg)
+{
+	void __user *argp = (void __user *)arg;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	switch (cmd) {
+	case NVM_INFO:
+		return nvm_ioctl_info(file, argp);
+	case NVM_GET_DEVICES:
+		return nvm_ioctl_get_devices(file, argp);
+	case NVM_DEV_CREATE:
+		return nvm_ioctl_dev_create(file, argp);
+	case NVM_DEV_REMOVE:
+		return nvm_ioctl_dev_remove(file, argp);
+	case NVM_DEV_INIT:
+		return nvm_ioctl_dev_init(file, argp);
+	case NVM_DEV_FACTORY:
+		return nvm_ioctl_dev_factory(file, argp);
+	}
+	return 0;
+}
+
+static const struct file_operations _ctl_fops = {
+	.open = nonseekable_open,
+	.unlocked_ioctl = nvm_ctl_ioctl,
+	.owner = THIS_MODULE,
+	.llseek  = noop_llseek,
+};
+
+static struct miscdevice _nvm_misc = {
+	.minor		= MISC_DYNAMIC_MINOR,
+	.name		= "lightnvm",
+	.nodename	= "lightnvm/control",
+	.fops		= &_ctl_fops,
+};
+builtin_misc_device(_nvm_misc);
diff --git a/src/kernel/linux/v4.19/drivers/lightnvm/pblk-cache.c b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-cache.c
new file mode 100644
index 0000000..f565a56
--- /dev/null
+++ b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-cache.c
@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@cnexlabs.com>
+ *                  Matias Bjorling <matias@cnexlabs.com>
+ *
+ * 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)
+{
+	struct request_queue *q = pblk->dev->q;
+	struct pblk_w_ctx w_ctx;
+	sector_t lba = pblk_get_lba(bio);
+	unsigned long start_time = jiffies;
+	unsigned int bpos, pos;
+	int nr_entries = pblk_get_secs(bio);
+	int i, ret;
+
+	generic_start_io_acct(q, REQ_OP_WRITE, bio_sectors(bio),
+			      &pblk->disk->part0);
+
+	/* 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);
+	switch (ret) {
+	case NVM_IO_REQUEUE:
+		io_schedule();
+		goto retry;
+	case NVM_IO_ERR:
+		pblk_pipeline_stop(pblk);
+		goto out;
+	}
+
+	pblk_ppa_set_empty(&w_ctx.ppa);
+	w_ctx.flags = flags;
+	if (bio->bi_opf & REQ_PREFLUSH) {
+		w_ctx.flags |= PBLK_FLUSH_ENTRY;
+		pblk_write_kick(pblk);
+	}
+
+	if (unlikely(!bio_has_data(bio)))
+		goto out;
+
+	for (i = 0; i < nr_entries; i++) {
+		void *data = bio_data(bio);
+
+		w_ctx.lba = lba + i;
+
+		pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + i);
+		pblk_rb_write_entry_user(&pblk->rwb, data, w_ctx, pos);
+
+		bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
+	}
+
+	atomic64_add(nr_entries, &pblk->user_wa);
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	atomic_long_add(nr_entries, &pblk->inflight_writes);
+	atomic_long_add(nr_entries, &pblk->req_writes);
+#endif
+
+	pblk_rl_inserted(&pblk->rl, nr_entries);
+
+out:
+	generic_end_io_acct(q, REQ_OP_WRITE, &pblk->disk->part0, start_time);
+	pblk_write_should_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, struct pblk_gc_rq *gc_rq)
+{
+	struct pblk_w_ctx w_ctx;
+	unsigned int bpos, pos;
+	void *data = gc_rq->data;
+	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, gc_rq->secs_to_gc, &bpos)) {
+		io_schedule();
+		goto retry;
+	}
+
+	w_ctx.flags = PBLK_IOTYPE_GC;
+	pblk_ppa_set_empty(&w_ctx.ppa);
+
+	for (i = 0, valid_entries = 0; i < gc_rq->nr_secs; i++) {
+		if (gc_rq->lba_list[i] == ADDR_EMPTY)
+			continue;
+
+		w_ctx.lba = gc_rq->lba_list[i];
+
+		pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + valid_entries);
+		pblk_rb_write_entry_gc(&pblk->rwb, data, w_ctx, gc_rq->line,
+						gc_rq->paddr_list[i], pos);
+
+		data += PBLK_EXPOSED_PAGE_SIZE;
+		valid_entries++;
+	}
+
+	WARN_ONCE(gc_rq->secs_to_gc != valid_entries,
+					"pblk: inconsistent GC write\n");
+
+	atomic64_add(valid_entries, &pblk->gc_wa);
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	atomic_long_add(valid_entries, &pblk->inflight_writes);
+	atomic_long_add(valid_entries, &pblk->recov_gc_writes);
+#endif
+
+	pblk_write_should_kick(pblk);
+	return NVM_IO_OK;
+}
diff --git a/src/kernel/linux/v4.19/drivers/lightnvm/pblk-core.c b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-core.c
new file mode 100644
index 0000000..8dce31d
--- /dev/null
+++ b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-core.c
@@ -0,0 +1,2095 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@cnexlabs.com>
+ *                  Matias Bjorling <matias@cnexlabs.com>
+ *
+ * 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"
+
+static 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);
+
+		pblk_err(pblk, "failed to mark bb, line:%d, pos:%d\n",
+				line->id, pos);
+	}
+
+	kfree(ppa);
+	mempool_free(line_ws, &pblk->gen_ws_pool);
+}
+
+static void pblk_mark_bb(struct pblk *pblk, struct pblk_line *line,
+			 struct ppa_addr ppa_addr)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct ppa_addr *ppa;
+	int pos = pblk_ppa_to_pos(geo, ppa_addr);
+
+	pblk_debug(pblk, "erase failed: line:%d, pos:%d\n", line->id, pos);
+	atomic_long_inc(&pblk->erase_failed);
+
+	atomic_dec(&line->blk_in_line);
+	if (test_and_set_bit(pos, line->blk_bitmap))
+		pblk_err(pblk, "attempted to erase bb: line:%d, pos:%d\n",
+							line->id, pos);
+
+	/* Not necessary to mark bad blocks on 2.0 spec. */
+	if (geo->version == NVM_OCSSD_SPEC_20)
+		return;
+
+	ppa = kmalloc(sizeof(struct ppa_addr), GFP_ATOMIC);
+	if (!ppa)
+		return;
+
+	*ppa = ppa_addr;
+	pblk_gen_run_ws(pblk, NULL, ppa, pblk_line_mark_bb,
+						GFP_ATOMIC, pblk->bb_wq);
+}
+
+static void __pblk_end_io_erase(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct nvm_chk_meta *chunk;
+	struct pblk_line *line;
+	int pos;
+
+	line = &pblk->lines[pblk_ppa_to_line(rqd->ppa_addr)];
+	pos = pblk_ppa_to_pos(geo, rqd->ppa_addr);
+	chunk = &line->chks[pos];
+
+	atomic_dec(&line->left_seblks);
+
+	if (rqd->error) {
+		chunk->state = NVM_CHK_ST_OFFLINE;
+		pblk_mark_bb(pblk, line, rqd->ppa_addr);
+	} else {
+		chunk->state = NVM_CHK_ST_FREE;
+	}
+
+	atomic_dec(&pblk->inflight_io);
+}
+
+/* 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->e_rq_pool);
+}
+
+/*
+ * Get information for all chunks from the device.
+ *
+ * The caller is responsible for freeing the returned structure
+ */
+struct nvm_chk_meta *pblk_chunk_get_info(struct pblk *pblk)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct nvm_chk_meta *meta;
+	struct ppa_addr ppa;
+	unsigned long len;
+	int ret;
+
+	ppa.ppa = 0;
+
+	len = geo->all_chunks * sizeof(*meta);
+	meta = kzalloc(len, GFP_KERNEL);
+	if (!meta)
+		return ERR_PTR(-ENOMEM);
+
+	ret = nvm_get_chunk_meta(dev, meta, ppa, geo->all_chunks);
+	if (ret) {
+		kfree(meta);
+		return ERR_PTR(-EIO);
+	}
+
+	return meta;
+}
+
+struct nvm_chk_meta *pblk_chunk_get_off(struct pblk *pblk,
+					      struct nvm_chk_meta *meta,
+					      struct ppa_addr ppa)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	int ch_off = ppa.m.grp * geo->num_chk * geo->num_lun;
+	int lun_off = ppa.m.pu * geo->num_chk;
+	int chk_off = ppa.m.chk;
+
+	return meta + ch_off + lun_off + chk_off;
+}
+
+void __pblk_map_invalidate(struct pblk *pblk, struct pblk_line *line,
+			   u64 paddr)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct list_head *move_list = NULL;
+
+	/* Lines being reclaimed (GC'ed) cannot be invalidated. Before the L2P
+	 * table is modified with reclaimed sectors, a check is done to endure
+	 * that newer updates are not overwritten.
+	 */
+	spin_lock(&line->lock);
+	WARN_ON(line->state == PBLK_LINESTATE_FREE);
+
+	if (test_and_set_bit(paddr, line->invalid_bitmap)) {
+		WARN_ONCE(1, "pblk: double invalidate\n");
+		spin_unlock(&line->lock);
+		return;
+	}
+	le32_add_cpu(line->vsc, -1);
+
+	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);
+		spin_lock(&line->lock);
+		/* Prevent moving a line that has just been chosen for GC */
+		if (line->state == PBLK_LINESTATE_GC) {
+			spin_unlock(&line->lock);
+			spin_unlock(&l_mg->gc_lock);
+			return;
+		}
+		spin_unlock(&line->lock);
+
+		list_move_tail(&line->list, move_list);
+		spin_unlock(&l_mg->gc_lock);
+	}
+}
+
+void pblk_map_invalidate(struct pblk *pblk, struct ppa_addr ppa)
+{
+	struct pblk_line *line;
+	u64 paddr;
+	int line_id;
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	/* Callers must ensure that the ppa points to a device address */
+	BUG_ON(pblk_addr_in_cache(ppa));
+	BUG_ON(pblk_ppa_empty(ppa));
+#endif
+
+	line_id = pblk_ppa_to_line(ppa);
+	line = &pblk->lines[line_id];
+	paddr = pblk_dev_ppa_to_line_addr(pblk, ppa);
+
+	__pblk_map_invalidate(pblk, line, paddr);
+}
+
+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;
+
+		ppa = pblk_trans_map_get(pblk, lba);
+
+		if (!pblk_addr_in_cache(ppa) && !pblk_ppa_empty(ppa))
+			pblk_map_invalidate(pblk, ppa);
+
+		pblk_ppa_set_empty(&ppa);
+		pblk_trans_map_set(pblk, lba, ppa);
+	}
+	spin_unlock(&pblk->trans_lock);
+}
+
+/* Caller must guarantee that the request is a valid type */
+struct nvm_rq *pblk_alloc_rqd(struct pblk *pblk, int type)
+{
+	mempool_t *pool;
+	struct nvm_rq *rqd;
+	int rq_size;
+
+	switch (type) {
+	case PBLK_WRITE:
+	case PBLK_WRITE_INT:
+		pool = &pblk->w_rq_pool;
+		rq_size = pblk_w_rq_size;
+		break;
+	case PBLK_READ:
+		pool = &pblk->r_rq_pool;
+		rq_size = pblk_g_rq_size;
+		break;
+	default:
+		pool = &pblk->e_rq_pool;
+		rq_size = pblk_g_rq_size;
+	}
+
+	rqd = mempool_alloc(pool, GFP_KERNEL);
+	memset(rqd, 0, rq_size);
+
+	return rqd;
+}
+
+/* Typically used on completion path. Cannot guarantee request consistency */
+void pblk_free_rqd(struct pblk *pblk, struct nvm_rq *rqd, int type)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	mempool_t *pool;
+
+	switch (type) {
+	case PBLK_WRITE:
+		kfree(((struct pblk_c_ctx *)nvm_rq_to_pdu(rqd))->lun_bitmap);
+		/* fall through */
+	case PBLK_WRITE_INT:
+		pool = &pblk->w_rq_pool;
+		break;
+	case PBLK_READ:
+		pool = &pblk->r_rq_pool;
+		break;
+	case PBLK_ERASE:
+		pool = &pblk->e_rq_pool;
+		break;
+	default:
+		pblk_err(pblk, "trying to free unknown rqd type\n");
+		return;
+	}
+
+	if (rqd->meta_list)
+		nvm_dev_dma_free(dev->parent, rqd->meta_list,
+				rqd->dma_meta_list);
+	mempool_free(rqd, pool);
+}
+
+void pblk_bio_free_pages(struct pblk *pblk, struct bio *bio, int off,
+			 int nr_pages)
+{
+	struct bio_vec *bv;
+	struct page *page;
+	int i, e, nbv = 0;
+
+	for (i = 0; i < bio->bi_vcnt; i++) {
+		bv = &bio->bi_io_vec[i];
+		page = bv->bv_page;
+		for (e = 0; e < bv->bv_len; e += PBLK_EXPOSED_PAGE_SIZE, nbv++)
+			if (nbv >= off)
+				mempool_free(page++, &pblk->page_bio_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_bio_pool, flags);
+
+		ret = bio_add_pc_page(q, bio, page, PBLK_EXPOSED_PAGE_SIZE, 0);
+		if (ret != PBLK_EXPOSED_PAGE_SIZE) {
+			pblk_err(pblk, "could not add page to bio\n");
+			mempool_free(page, &pblk->page_bio_pool);
+			goto err;
+		}
+	}
+
+	return 0;
+err:
+	pblk_bio_free_pages(pblk, bio, (bio->bi_vcnt - i), i);
+	return -1;
+}
+
+void pblk_write_kick(struct pblk *pblk)
+{
+	wake_up_process(pblk->writer_ts);
+	mod_timer(&pblk->wtimer, jiffies + msecs_to_jiffies(1000));
+}
+
+void pblk_write_timer_fn(struct timer_list *t)
+{
+	struct pblk *pblk = from_timer(pblk, t, wtimer);
+
+	/* kick the write thread every tick to flush outstanding data */
+	pblk_write_kick(pblk);
+}
+
+void pblk_write_should_kick(struct pblk *pblk)
+{
+	unsigned int secs_avail = pblk_rb_read_count(&pblk->rwb);
+
+	if (secs_avail >= pblk->min_write_pgs)
+		pblk_write_kick(pblk);
+}
+
+static void pblk_wait_for_meta(struct pblk *pblk)
+{
+	do {
+		if (!atomic_read(&pblk->inflight_io))
+			break;
+
+		schedule();
+	} while (1);
+}
+
+static void pblk_flush_writer(struct pblk *pblk)
+{
+	pblk_rb_flush(&pblk->rwb);
+	do {
+		if (!pblk_rb_sync_count(&pblk->rwb))
+			break;
+
+		pblk_write_kick(pblk);
+		schedule();
+	} while (1);
+}
+
+struct list_head *pblk_line_gc_list(struct pblk *pblk, struct pblk_line *line)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct list_head *move_list = NULL;
+	int vsc = le32_to_cpu(*line->vsc);
+
+	lockdep_assert_held(&line->lock);
+
+	if (line->w_err_gc->has_write_err) {
+		if (line->gc_group != PBLK_LINEGC_WERR) {
+			line->gc_group = PBLK_LINEGC_WERR;
+			move_list = &l_mg->gc_werr_list;
+			pblk_rl_werr_line_in(&pblk->rl);
+		}
+	} else if (!vsc) {
+		if (line->gc_group != PBLK_LINEGC_FULL) {
+			line->gc_group = PBLK_LINEGC_FULL;
+			move_list = &l_mg->gc_full_list;
+		}
+	} else if (vsc < lm->high_thrs) {
+		if (line->gc_group != PBLK_LINEGC_HIGH) {
+			line->gc_group = PBLK_LINEGC_HIGH;
+			move_list = &l_mg->gc_high_list;
+		}
+	} else if (vsc < lm->mid_thrs) {
+		if (line->gc_group != PBLK_LINEGC_MID) {
+			line->gc_group = PBLK_LINEGC_MID;
+			move_list = &l_mg->gc_mid_list;
+		}
+	} else if (vsc < line->sec_in_line) {
+		if (line->gc_group != PBLK_LINEGC_LOW) {
+			line->gc_group = PBLK_LINEGC_LOW;
+			move_list = &l_mg->gc_low_list;
+		}
+	} else if (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;
+		pblk_err(pblk, "corrupted vsc for line %d, vsc:%d (%d/%d/%d)\n",
+						line->id, 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);
+}
+
+void pblk_log_write_err(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	atomic_long_inc(&pblk->write_failed);
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	pblk_print_failed_rqd(pblk, rqd, rqd->error);
+#endif
+}
+
+void pblk_log_read_err(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	/* Empty page read is not necessarily an error (e.g., L2P recovery) */
+	if (rqd->error == NVM_RSP_ERR_EMPTYPAGE) {
+		atomic_long_inc(&pblk->read_empty);
+		return;
+	}
+
+	switch (rqd->error) {
+	case NVM_RSP_WARN_HIGHECC:
+		atomic_long_inc(&pblk->read_high_ecc);
+		break;
+	case NVM_RSP_ERR_FAILECC:
+	case NVM_RSP_ERR_FAILCRC:
+		atomic_long_inc(&pblk->read_failed);
+		break;
+	default:
+		pblk_err(pblk, "unknown read error:%d\n", rqd->error);
+	}
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	pblk_print_failed_rqd(pblk, rqd, rqd->error);
+#endif
+}
+
+void pblk_set_sec_per_write(struct pblk *pblk, int sec_per_write)
+{
+	pblk->sec_per_write = sec_per_write;
+}
+
+int pblk_submit_io(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+
+	atomic_inc(&pblk->inflight_io);
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	if (pblk_check_io(pblk, rqd))
+		return NVM_IO_ERR;
+#endif
+
+	return nvm_submit_io(dev, rqd);
+}
+
+int pblk_submit_io_sync(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+
+	atomic_inc(&pblk->inflight_io);
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	if (pblk_check_io(pblk, rqd))
+		return NVM_IO_ERR;
+#endif
+
+	return nvm_submit_io_sync(dev, rqd);
+}
+
+static void pblk_bio_map_addr_endio(struct bio *bio)
+{
+	bio_put(bio);
+}
+
+struct bio *pblk_bio_map_addr(struct pblk *pblk, void *data,
+			      unsigned int nr_secs, unsigned int len,
+			      int alloc_type, gfp_t gfp_mask)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	void *kaddr = data;
+	struct page *page;
+	struct bio *bio;
+	int i, ret;
+
+	if (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) {
+			pblk_err(pblk, "could not map vmalloc bio\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) {
+			pblk_err(pblk, "could not add page to bio\n");
+			bio_put(bio);
+			bio = ERR_PTR(-ENOMEM);
+			goto out;
+		}
+
+		kaddr += PAGE_SIZE;
+	}
+
+	bio->bi_end_io = pblk_bio_map_addr_endio;
+out:
+	return bio;
+}
+
+int pblk_calc_secs(struct pblk *pblk, unsigned long secs_avail,
+		   unsigned long secs_to_flush)
+{
+	int max = pblk->sec_per_write;
+	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;
+}
+
+void pblk_dealloc_page(struct pblk *pblk, struct pblk_line *line, int nr_secs)
+{
+	u64 addr;
+	int i;
+
+	spin_lock(&line->lock);
+	addr = find_next_zero_bit(line->map_bitmap,
+					pblk->lm.sec_per_line, line->cur_sec);
+	line->cur_sec = addr - nr_secs;
+
+	for (i = 0; i < nr_secs; i++, line->cur_sec--)
+		WARN_ON(!test_and_clear_bit(line->cur_sec, line->map_bitmap));
+	spin_unlock(&line->lock);
+}
+
+u64 __pblk_alloc_page(struct pblk *pblk, struct pblk_line *line, int nr_secs)
+{
+	u64 addr;
+	int i;
+
+	lockdep_assert_held(&line->lock);
+
+	/* logic error: ppa out-of-bounds. Prevent generating bad address */
+	if (line->cur_sec + nr_secs > pblk->lm.sec_per_line) {
+		WARN(1, "pblk: page allocation out of bounds\n");
+		nr_secs = pblk->lm.sec_per_line - line->cur_sec;
+	}
+
+	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;
+	WARN(line->left_msecs < 0, "pblk: page allocation out of bounds\n");
+	spin_unlock(&line->lock);
+
+	return addr;
+}
+
+u64 pblk_lookup_page(struct pblk *pblk, struct pblk_line *line)
+{
+	u64 paddr;
+
+	spin_lock(&line->lock);
+	paddr = find_next_zero_bit(line->map_bitmap,
+					pblk->lm.sec_per_line, line->cur_sec);
+	spin_unlock(&line->lock);
+
+	return paddr;
+}
+
+/*
+ * Submit emeta to one LUN in the raid line at the time to avoid a deadlock when
+ * taking the per LUN semaphore.
+ */
+static int pblk_line_submit_emeta_io(struct pblk *pblk, struct pblk_line *line,
+				     void *emeta_buf, u64 paddr, int dir)
+{
+	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;
+	void *ppa_list, *meta_list;
+	struct bio *bio;
+	struct nvm_rq rqd;
+	dma_addr_t dma_ppa_list, dma_meta_list;
+	int min = pblk->min_write_pgs;
+	int left_ppas = lm->emeta_sec[0];
+	int id = line->id;
+	int rq_ppas, rq_len;
+	int cmd_op, bio_op;
+	int i, j;
+	int ret;
+
+	if (dir == PBLK_WRITE) {
+		bio_op = REQ_OP_WRITE;
+		cmd_op = NVM_OP_PWRITE;
+	} else if (dir == PBLK_READ) {
+		bio_op = REQ_OP_READ;
+		cmd_op = NVM_OP_PREAD;
+	} else
+		return -EINVAL;
+
+	meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
+							&dma_meta_list);
+	if (!meta_list)
+		return -ENOMEM;
+
+	ppa_list = meta_list + pblk_dma_meta_size;
+	dma_ppa_list = dma_meta_list + pblk_dma_meta_size;
+
+next_rq:
+	memset(&rqd, 0, sizeof(struct nvm_rq));
+
+	rq_ppas = pblk_calc_secs(pblk, left_ppas, 0);
+	rq_len = rq_ppas * geo->csecs;
+
+	bio = pblk_bio_map_addr(pblk, emeta_buf, rq_ppas, rq_len,
+					l_mg->emeta_alloc_type, GFP_KERNEL);
+	if (IS_ERR(bio)) {
+		ret = PTR_ERR(bio);
+		goto free_rqd_dma;
+	}
+
+	bio->bi_iter.bi_sector = 0; /* internal bio */
+	bio_set_op_attrs(bio, bio_op, 0);
+
+	rqd.bio = bio;
+	rqd.meta_list = meta_list;
+	rqd.ppa_list = ppa_list;
+	rqd.dma_meta_list = dma_meta_list;
+	rqd.dma_ppa_list = dma_ppa_list;
+	rqd.opcode = cmd_op;
+	rqd.nr_ppas = rq_ppas;
+
+	if (dir == PBLK_WRITE) {
+		struct pblk_sec_meta *meta_list = rqd.meta_list;
+
+		rqd.flags = pblk_set_progr_mode(pblk, PBLK_WRITE);
+		for (i = 0; i < rqd.nr_ppas; ) {
+			spin_lock(&line->lock);
+			paddr = __pblk_alloc_page(pblk, line, min);
+			spin_unlock(&line->lock);
+			for (j = 0; j < min; j++, i++, paddr++) {
+				meta_list[i].lba = cpu_to_le64(ADDR_EMPTY);
+				rqd.ppa_list[i] =
+					addr_to_gen_ppa(pblk, paddr, id);
+			}
+		}
+	} else {
+		for (i = 0; i < rqd.nr_ppas; ) {
+			struct ppa_addr ppa = addr_to_gen_ppa(pblk, paddr, id);
+			int pos = pblk_ppa_to_pos(geo, ppa);
+			int read_type = PBLK_READ_RANDOM;
+
+			if (pblk_io_aligned(pblk, rq_ppas))
+				read_type = PBLK_READ_SEQUENTIAL;
+			rqd.flags = pblk_set_read_mode(pblk, read_type);
+
+			while (test_bit(pos, line->blk_bitmap)) {
+				paddr += min;
+				if (pblk_boundary_paddr_checks(pblk, paddr)) {
+					pblk_err(pblk, "corrupt emeta line:%d\n",
+								line->id);
+					bio_put(bio);
+					ret = -EINTR;
+					goto free_rqd_dma;
+				}
+
+				ppa = addr_to_gen_ppa(pblk, paddr, id);
+				pos = pblk_ppa_to_pos(geo, ppa);
+			}
+
+			if (pblk_boundary_paddr_checks(pblk, paddr + min)) {
+				pblk_err(pblk, "corrupt emeta line:%d\n",
+								line->id);
+				bio_put(bio);
+				ret = -EINTR;
+				goto free_rqd_dma;
+			}
+
+			for (j = 0; j < min; j++, i++, paddr++)
+				rqd.ppa_list[i] =
+					addr_to_gen_ppa(pblk, paddr, line->id);
+		}
+	}
+
+	ret = pblk_submit_io_sync(pblk, &rqd);
+	if (ret) {
+		pblk_err(pblk, "emeta I/O submission failed: %d\n", ret);
+		bio_put(bio);
+		goto free_rqd_dma;
+	}
+
+	atomic_dec(&pblk->inflight_io);
+
+	if (rqd.error) {
+		if (dir == PBLK_WRITE)
+			pblk_log_write_err(pblk, &rqd);
+		else
+			pblk_log_read_err(pblk, &rqd);
+	}
+
+	emeta_buf += rq_len;
+	left_ppas -= rq_ppas;
+	if (left_ppas)
+		goto next_rq;
+free_rqd_dma:
+	nvm_dev_dma_free(dev->parent, rqd.meta_list, rqd.dma_meta_list);
+	return ret;
+}
+
+u64 pblk_line_smeta_start(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;
+	int bit;
+
+	/* This usually only happens on bad lines */
+	bit = find_first_zero_bit(line->blk_bitmap, lm->blk_per_line);
+	if (bit >= lm->blk_per_line)
+		return -1;
+
+	return bit * geo->ws_opt;
+}
+
+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;
+	__le64 *lba_list = NULL;
+	int i, ret;
+	int cmd_op, bio_op;
+	int flags;
+
+	if (dir == PBLK_WRITE) {
+		bio_op = REQ_OP_WRITE;
+		cmd_op = NVM_OP_PWRITE;
+		flags = pblk_set_progr_mode(pblk, PBLK_WRITE);
+		lba_list = emeta_to_lbas(pblk, line->emeta->buf);
+	} else if (dir == PBLK_READ_RECOV || dir == PBLK_READ) {
+		bio_op = REQ_OP_READ;
+		cmd_op = NVM_OP_PREAD;
+		flags = pblk_set_read_mode(pblk, PBLK_READ_SEQUENTIAL);
+	} else
+		return -EINVAL;
+
+	memset(&rqd, 0, sizeof(struct nvm_rq));
+
+	rqd.meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
+							&rqd.dma_meta_list);
+	if (!rqd.meta_list)
+		return -ENOMEM;
+
+	rqd.ppa_list = rqd.meta_list + pblk_dma_meta_size;
+	rqd.dma_ppa_list = rqd.dma_meta_list + pblk_dma_meta_size;
+
+	bio = bio_map_kern(dev->q, line->smeta, lm->smeta_len, GFP_KERNEL);
+	if (IS_ERR(bio)) {
+		ret = PTR_ERR(bio);
+		goto free_ppa_list;
+	}
+
+	bio->bi_iter.bi_sector = 0; /* internal bio */
+	bio_set_op_attrs(bio, bio_op, 0);
+
+	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++) {
+		struct pblk_sec_meta *meta_list = rqd.meta_list;
+
+		rqd.ppa_list[i] = addr_to_gen_ppa(pblk, paddr, line->id);
+
+		if (dir == PBLK_WRITE) {
+			__le64 addr_empty = cpu_to_le64(ADDR_EMPTY);
+
+			meta_list[i].lba = 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_sync(pblk, &rqd);
+	if (ret) {
+		pblk_err(pblk, "smeta I/O submission failed: %d\n", ret);
+		bio_put(bio);
+		goto free_ppa_list;
+	}
+
+	atomic_dec(&pblk->inflight_io);
+
+	if (rqd.error) {
+		if (dir == PBLK_WRITE) {
+			pblk_log_write_err(pblk, &rqd);
+			ret = 1;
+		} else if (dir == PBLK_READ)
+			pblk_log_read_err(pblk, &rqd);
+	}
+
+free_ppa_list:
+	nvm_dev_dma_free(dev->parent, rqd.meta_list, rqd.dma_meta_list);
+
+	return ret;
+}
+
+int pblk_line_read_smeta(struct pblk *pblk, struct pblk_line *line)
+{
+	u64 bpaddr = pblk_line_smeta_start(pblk, line);
+
+	return pblk_line_submit_smeta_io(pblk, line, bpaddr, PBLK_READ_RECOV);
+}
+
+int pblk_line_read_emeta(struct pblk *pblk, struct pblk_line *line,
+			 void *emeta_buf)
+{
+	return pblk_line_submit_emeta_io(pblk, line, emeta_buf,
+						line->emeta_ssec, PBLK_READ);
+}
+
+static void pblk_setup_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, PBLK_ERASE);
+	rqd->bio = NULL;
+}
+
+static int pblk_blk_erase_sync(struct pblk *pblk, struct ppa_addr ppa)
+{
+	struct nvm_rq rqd = {NULL};
+	int ret;
+
+	pblk_setup_e_rq(pblk, &rqd, ppa);
+
+	/* 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_sync(pblk, &rqd);
+	rqd.private = pblk;
+	__pblk_end_io_erase(pblk, &rqd);
+
+	return ret;
+}
+
+int pblk_line_erase(struct pblk *pblk, struct pblk_line *line)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct ppa_addr ppa;
+	int ret, bit = -1;
+
+	/* Erase only good blocks, one at a time */
+	do {
+		spin_lock(&line->lock);
+		bit = find_next_zero_bit(line->erase_bitmap, lm->blk_per_line,
+								bit + 1);
+		if (bit >= lm->blk_per_line) {
+			spin_unlock(&line->lock);
+			break;
+		}
+
+		ppa = pblk->luns[bit].bppa; /* set ch and lun */
+		ppa.a.blk = line->id;
+
+		atomic_dec(&line->left_eblks);
+		WARN_ON(test_and_set_bit(bit, line->erase_bitmap));
+		spin_unlock(&line->lock);
+
+		ret = pblk_blk_erase_sync(pblk, ppa);
+		if (ret) {
+			pblk_err(pblk, "failed to erase line %d\n", line->id);
+			return ret;
+		}
+	} while (1);
+
+	return 0;
+}
+
+static void pblk_line_setup_metadata(struct pblk_line *line,
+				     struct pblk_line_mgmt *l_mg,
+				     struct pblk_line_meta *lm)
+{
+	int meta_line;
+
+	lockdep_assert_held(&l_mg->free_lock);
+
+retry_meta:
+	meta_line = find_first_zero_bit(&l_mg->meta_bitmap, PBLK_DATA_LINES);
+	if (meta_line == PBLK_DATA_LINES) {
+		spin_unlock(&l_mg->free_lock);
+		io_schedule();
+		spin_lock(&l_mg->free_lock);
+		goto retry_meta;
+	}
+
+	set_bit(meta_line, &l_mg->meta_bitmap);
+	line->meta_line = meta_line;
+
+	line->smeta = l_mg->sline_meta[meta_line];
+	line->emeta = l_mg->eline_meta[meta_line];
+
+	memset(line->smeta, 0, lm->smeta_len);
+	memset(line->emeta->buf, 0, lm->emeta_len[0]);
+
+	line->emeta->mem = 0;
+	atomic_set(&line->emeta->sync, 0);
+}
+
+/* For now lines are always assumed full lines. Thus, smeta former and current
+ * lun bitmaps are omitted.
+ */
+static int pblk_line_init_metadata(struct pblk *pblk, struct pblk_line *line,
+				  struct pblk_line *cur)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_emeta *emeta = line->emeta;
+	struct line_emeta *emeta_buf = emeta->buf;
+	struct line_smeta *smeta_buf = (struct line_smeta *)line->smeta;
+	int nr_blk_line;
+
+	/* After erasing the line, new bad blocks might appear and we risk
+	 * having an invalid line
+	 */
+	nr_blk_line = lm->blk_per_line -
+			bitmap_weight(line->blk_bitmap, lm->blk_per_line);
+	if (nr_blk_line < lm->min_blk_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);
+
+		pblk_debug(pblk, "line %d is bad\n", line->id);
+
+		return 0;
+	}
+
+	/* Run-time metadata */
+	line->lun_bitmap = ((void *)(smeta_buf)) + sizeof(struct line_smeta);
+
+	/* Mark LUNs allocated in this line (all for now) */
+	bitmap_set(line->lun_bitmap, 0, lm->lun_bitmap_len);
+
+	smeta_buf->header.identifier = cpu_to_le32(PBLK_MAGIC);
+	memcpy(smeta_buf->header.uuid, pblk->instance_uuid, 16);
+	smeta_buf->header.id = cpu_to_le32(line->id);
+	smeta_buf->header.type = cpu_to_le16(line->type);
+	smeta_buf->header.version_major = SMETA_VERSION_MAJOR;
+	smeta_buf->header.version_minor = SMETA_VERSION_MINOR;
+
+	/* Start metadata */
+	smeta_buf->seq_nr = cpu_to_le64(line->seq_nr);
+	smeta_buf->window_wr_lun = cpu_to_le32(geo->all_luns);
+
+	/* Fill metadata among lines */
+	if (cur) {
+		memcpy(line->lun_bitmap, cur->lun_bitmap, lm->lun_bitmap_len);
+		smeta_buf->prev_id = cpu_to_le32(cur->id);
+		cur->emeta->buf->next_id = cpu_to_le32(line->id);
+	} else {
+		smeta_buf->prev_id = cpu_to_le32(PBLK_LINE_EMPTY);
+	}
+
+	/* All smeta must be set at this point */
+	smeta_buf->header.crc = cpu_to_le32(
+			pblk_calc_meta_header_crc(pblk, &smeta_buf->header));
+	smeta_buf->crc = cpu_to_le32(pblk_calc_smeta_crc(pblk, smeta_buf));
+
+	/* End metadata */
+	memcpy(&emeta_buf->header, &smeta_buf->header,
+						sizeof(struct line_header));
+
+	emeta_buf->header.version_major = EMETA_VERSION_MAJOR;
+	emeta_buf->header.version_minor = EMETA_VERSION_MINOR;
+	emeta_buf->header.crc = cpu_to_le32(
+			pblk_calc_meta_header_crc(pblk, &emeta_buf->header));
+
+	emeta_buf->seq_nr = cpu_to_le64(line->seq_nr);
+	emeta_buf->nr_lbas = cpu_to_le64(line->sec_in_line);
+	emeta_buf->nr_valid_lbas = cpu_to_le64(0);
+	emeta_buf->next_id = cpu_to_le32(PBLK_LINE_EMPTY);
+	emeta_buf->crc = cpu_to_le32(0);
+	emeta_buf->prev_id = smeta_buf->prev_id;
+
+	return 1;
+}
+
+static int pblk_line_alloc_bitmaps(struct pblk *pblk, struct pblk_line *line)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+
+	line->map_bitmap = kzalloc(lm->sec_bitmap_len, GFP_KERNEL);
+	if (!line->map_bitmap)
+		return -ENOMEM;
+
+	/* will be initialized using bb info from map_bitmap */
+	line->invalid_bitmap = kmalloc(lm->sec_bitmap_len, GFP_KERNEL);
+	if (!line->invalid_bitmap) {
+		kfree(line->map_bitmap);
+		line->map_bitmap = NULL;
+		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_init_bb(struct pblk *pblk, struct pblk_line *line,
+			     int init)
+{
+	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;
+	u64 off;
+	int bit = -1;
+	int emeta_secs;
+
+	line->sec_in_line = lm->sec_per_line;
+
+	/* Capture bad block information on line mapping bitmaps */
+	while ((bit = find_next_bit(line->blk_bitmap, lm->blk_per_line,
+					bit + 1)) < lm->blk_per_line) {
+		off = bit * geo->ws_opt;
+		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->clba;
+	}
+
+	/* Mark smeta metadata sectors as bad sectors */
+	bit = find_first_zero_bit(line->blk_bitmap, lm->blk_per_line);
+	off = bit * geo->ws_opt;
+	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;
+
+	if (init && pblk_line_submit_smeta_io(pblk, line, off, PBLK_WRITE)) {
+		pblk_debug(pblk, "line smeta I/O failed. Retry\n");
+		return 0;
+	}
+
+	bitmap_copy(line->invalid_bitmap, line->map_bitmap, lm->sec_per_line);
+
+	/* Mark emeta metadata sectors as bad sectors. We need to consider bad
+	 * blocks to make sure that there are enough sectors to store emeta
+	 */
+	emeta_secs = lm->emeta_sec[0];
+	off = lm->sec_per_line;
+	while (emeta_secs) {
+		off -= geo->ws_opt;
+		if (!test_bit(off, line->invalid_bitmap)) {
+			bitmap_set(line->invalid_bitmap, off, geo->ws_opt);
+			emeta_secs -= geo->ws_opt;
+		}
+	}
+
+	line->emeta_ssec = off;
+	line->sec_in_line -= lm->emeta_sec[0];
+	line->nr_valid_lbas = 0;
+	line->left_msecs = line->sec_in_line;
+	*line->vsc = cpu_to_le32(line->sec_in_line);
+
+	if (lm->sec_per_line - line->sec_in_line !=
+		bitmap_weight(line->invalid_bitmap, lm->sec_per_line)) {
+		spin_lock(&line->lock);
+		line->state = PBLK_LINESTATE_BAD;
+		spin_unlock(&line->lock);
+
+		list_add_tail(&line->list, &l_mg->bad_list);
+		pblk_err(pblk, "unexpected line %d is bad\n", line->id);
+
+		return 0;
+	}
+
+	return 1;
+}
+
+static int pblk_prepare_new_line(struct pblk *pblk, struct pblk_line *line)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	int blk_to_erase = atomic_read(&line->blk_in_line);
+	int i;
+
+	for (i = 0; i < lm->blk_per_line; i++) {
+		struct pblk_lun *rlun = &pblk->luns[i];
+		int pos = pblk_ppa_to_pos(geo, rlun->bppa);
+		int state = line->chks[pos].state;
+
+		/* Free chunks should not be erased */
+		if (state & NVM_CHK_ST_FREE) {
+			set_bit(pblk_ppa_to_pos(geo, rlun->bppa),
+							line->erase_bitmap);
+			blk_to_erase--;
+		}
+	}
+
+	return blk_to_erase;
+}
+
+static int pblk_line_prepare(struct pblk *pblk, struct pblk_line *line)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	int blk_in_line = atomic_read(&line->blk_in_line);
+	int blk_to_erase;
+
+	/* Bad blocks do not need to be erased */
+	bitmap_copy(line->erase_bitmap, line->blk_bitmap, lm->blk_per_line);
+
+	spin_lock(&line->lock);
+
+	/* If we have not written to this line, we need to mark up free chunks
+	 * as already erased
+	 */
+	if (line->state == PBLK_LINESTATE_NEW) {
+		blk_to_erase = pblk_prepare_new_line(pblk, line);
+		line->state = PBLK_LINESTATE_FREE;
+	} else {
+		blk_to_erase = blk_in_line;
+	}
+
+	if (blk_in_line < lm->min_blk_line) {
+		spin_unlock(&line->lock);
+		return -EAGAIN;
+	}
+
+	if (line->state != PBLK_LINESTATE_FREE) {
+		WARN(1, "pblk: corrupted line %d, state %d\n",
+							line->id, line->state);
+		spin_unlock(&line->lock);
+		return -EINTR;
+	}
+
+	line->state = PBLK_LINESTATE_OPEN;
+
+	atomic_set(&line->left_eblks, blk_to_erase);
+	atomic_set(&line->left_seblks, blk_to_erase);
+
+	line->meta_distance = lm->meta_distance;
+	spin_unlock(&line->lock);
+
+	kref_init(&line->ref);
+
+	return 0;
+}
+
+int pblk_line_recov_alloc(struct pblk *pblk, struct pblk_line *line)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	int ret;
+
+	spin_lock(&l_mg->free_lock);
+	l_mg->data_line = line;
+	list_del(&line->list);
+
+	ret = pblk_line_prepare(pblk, line);
+	if (ret) {
+		list_add(&line->list, &l_mg->free_list);
+		spin_unlock(&l_mg->free_lock);
+		return ret;
+	}
+	spin_unlock(&l_mg->free_lock);
+
+	ret = pblk_line_alloc_bitmaps(pblk, line);
+	if (ret)
+		goto fail;
+
+	if (!pblk_line_init_bb(pblk, line, 0)) {
+		ret = -EINTR;
+		goto fail;
+	}
+
+	pblk_rl_free_lines_dec(&pblk->rl, line, true);
+	return 0;
+
+fail:
+	spin_lock(&l_mg->free_lock);
+	list_add(&line->list, &l_mg->free_list);
+	spin_unlock(&l_mg->free_lock);
+
+	return ret;
+}
+
+void pblk_line_recov_close(struct pblk *pblk, struct pblk_line *line)
+{
+	kfree(line->map_bitmap);
+	line->map_bitmap = NULL;
+	line->smeta = NULL;
+	line->emeta = NULL;
+}
+
+static void pblk_line_reinit(struct pblk_line *line)
+{
+	*line->vsc = cpu_to_le32(EMPTY_ENTRY);
+
+	line->map_bitmap = NULL;
+	line->invalid_bitmap = NULL;
+	line->smeta = NULL;
+	line->emeta = NULL;
+}
+
+void pblk_line_free(struct pblk_line *line)
+{
+	kfree(line->map_bitmap);
+	kfree(line->invalid_bitmap);
+
+	pblk_line_reinit(line);
+}
+
+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;
+	int ret, bit;
+
+	lockdep_assert_held(&l_mg->free_lock);
+
+retry:
+	if (list_empty(&l_mg->free_list)) {
+		pblk_err(pblk, "no free lines\n");
+		return NULL;
+	}
+
+	line = list_first_entry(&l_mg->free_list, struct pblk_line, list);
+	list_del(&line->list);
+	l_mg->nr_free_lines--;
+
+	bit = find_first_zero_bit(line->blk_bitmap, lm->blk_per_line);
+	if (unlikely(bit >= lm->blk_per_line)) {
+		spin_lock(&line->lock);
+		line->state = PBLK_LINESTATE_BAD;
+		spin_unlock(&line->lock);
+
+		list_add_tail(&line->list, &l_mg->bad_list);
+
+		pblk_debug(pblk, "line %d is bad\n", line->id);
+		goto retry;
+	}
+
+	ret = pblk_line_prepare(pblk, line);
+	if (ret) {
+		switch (ret) {
+		case -EAGAIN:
+			list_add(&line->list, &l_mg->bad_list);
+			goto retry;
+		case -EINTR:
+			list_add(&line->list, &l_mg->corrupt_list);
+			goto retry;
+		default:
+			pblk_err(pblk, "failed to prepare line %d\n", line->id);
+			list_add(&line->list, &l_mg->free_list);
+			l_mg->nr_free_lines++;
+			return NULL;
+		}
+	}
+
+	return line;
+}
+
+static struct pblk_line *pblk_line_retry(struct pblk *pblk,
+					 struct pblk_line *line)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line *retry_line;
+
+retry:
+	spin_lock(&l_mg->free_lock);
+	retry_line = pblk_line_get(pblk);
+	if (!retry_line) {
+		l_mg->data_line = NULL;
+		spin_unlock(&l_mg->free_lock);
+		return NULL;
+	}
+
+	retry_line->map_bitmap = line->map_bitmap;
+	retry_line->invalid_bitmap = line->invalid_bitmap;
+	retry_line->smeta = line->smeta;
+	retry_line->emeta = line->emeta;
+	retry_line->meta_line = line->meta_line;
+
+	pblk_line_reinit(line);
+
+	l_mg->data_line = retry_line;
+	spin_unlock(&l_mg->free_lock);
+
+	pblk_rl_free_lines_dec(&pblk->rl, line, false);
+
+	if (pblk_line_erase(pblk, retry_line))
+		goto retry;
+
+	return retry_line;
+}
+
+static void pblk_set_space_limit(struct pblk *pblk)
+{
+	struct pblk_rl *rl = &pblk->rl;
+
+	atomic_set(&rl->rb_space, 0);
+}
+
+struct pblk_line *pblk_line_get_first_data(struct pblk *pblk)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line *line;
+
+	spin_lock(&l_mg->free_lock);
+	line = pblk_line_get(pblk);
+	if (!line) {
+		spin_unlock(&l_mg->free_lock);
+		return NULL;
+	}
+
+	line->seq_nr = l_mg->d_seq_nr++;
+	line->type = PBLK_LINETYPE_DATA;
+	l_mg->data_line = line;
+
+	pblk_line_setup_metadata(line, l_mg, &pblk->lm);
+
+	/* Allocate next line for preparation */
+	l_mg->data_next = pblk_line_get(pblk);
+	if (!l_mg->data_next) {
+		/* If we cannot get a new line, we need to stop the pipeline.
+		 * Only allow as many writes in as we can store safely and then
+		 * fail gracefully
+		 */
+		pblk_set_space_limit(pblk);
+
+		l_mg->data_next = NULL;
+	} else {
+		l_mg->data_next->seq_nr = l_mg->d_seq_nr++;
+		l_mg->data_next->type = PBLK_LINETYPE_DATA;
+	}
+	spin_unlock(&l_mg->free_lock);
+
+	if (pblk_line_alloc_bitmaps(pblk, line))
+		return NULL;
+
+	if (pblk_line_erase(pblk, line)) {
+		line = pblk_line_retry(pblk, line);
+		if (!line)
+			return NULL;
+	}
+
+retry_setup:
+	if (!pblk_line_init_metadata(pblk, line, NULL)) {
+		line = pblk_line_retry(pblk, line);
+		if (!line)
+			return NULL;
+
+		goto retry_setup;
+	}
+
+	if (!pblk_line_init_bb(pblk, line, 1)) {
+		line = pblk_line_retry(pblk, line);
+		if (!line)
+			return NULL;
+
+		goto retry_setup;
+	}
+
+	pblk_rl_free_lines_dec(&pblk->rl, line, true);
+
+	return line;
+}
+
+static void pblk_stop_writes(struct pblk *pblk, struct pblk_line *line)
+{
+	lockdep_assert_held(&pblk->l_mg.free_lock);
+
+	pblk_set_space_limit(pblk);
+	pblk->state = PBLK_STATE_STOPPING;
+}
+
+static void pblk_line_close_meta_sync(struct pblk *pblk)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_line *line, *tline;
+	LIST_HEAD(list);
+
+	spin_lock(&l_mg->close_lock);
+	if (list_empty(&l_mg->emeta_list)) {
+		spin_unlock(&l_mg->close_lock);
+		return;
+	}
+
+	list_cut_position(&list, &l_mg->emeta_list, l_mg->emeta_list.prev);
+	spin_unlock(&l_mg->close_lock);
+
+	list_for_each_entry_safe(line, tline, &list, list) {
+		struct pblk_emeta *emeta = line->emeta;
+
+		while (emeta->mem < lm->emeta_len[0]) {
+			int ret;
+
+			ret = pblk_submit_meta_io(pblk, line);
+			if (ret) {
+				pblk_err(pblk, "sync meta line %d failed (%d)\n",
+							line->id, ret);
+				return;
+			}
+		}
+	}
+
+	pblk_wait_for_meta(pblk);
+	flush_workqueue(pblk->close_wq);
+}
+
+void __pblk_pipeline_flush(struct pblk *pblk)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	int ret;
+
+	spin_lock(&l_mg->free_lock);
+	if (pblk->state == PBLK_STATE_RECOVERING ||
+					pblk->state == PBLK_STATE_STOPPED) {
+		spin_unlock(&l_mg->free_lock);
+		return;
+	}
+	pblk->state = PBLK_STATE_RECOVERING;
+	spin_unlock(&l_mg->free_lock);
+
+	pblk_flush_writer(pblk);
+	pblk_wait_for_meta(pblk);
+
+	ret = pblk_recov_pad(pblk);
+	if (ret) {
+		pblk_err(pblk, "could not close data on teardown(%d)\n", ret);
+		return;
+	}
+
+	flush_workqueue(pblk->bb_wq);
+	pblk_line_close_meta_sync(pblk);
+}
+
+void __pblk_pipeline_stop(struct pblk *pblk)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+
+	spin_lock(&l_mg->free_lock);
+	pblk->state = PBLK_STATE_STOPPED;
+	l_mg->data_line = NULL;
+	l_mg->data_next = NULL;
+	spin_unlock(&l_mg->free_lock);
+}
+
+void pblk_pipeline_stop(struct pblk *pblk)
+{
+	__pblk_pipeline_flush(pblk);
+	__pblk_pipeline_stop(pblk);
+}
+
+struct pblk_line *pblk_line_replace_data(struct pblk *pblk)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line *cur, *new = NULL;
+	unsigned int left_seblks;
+
+	new = l_mg->data_next;
+	if (!new)
+		goto out;
+
+	spin_lock(&l_mg->free_lock);
+	cur = l_mg->data_line;
+	l_mg->data_line = new;
+
+	pblk_line_setup_metadata(new, l_mg, &pblk->lm);
+	spin_unlock(&l_mg->free_lock);
+
+retry_erase:
+	left_seblks = atomic_read(&new->left_seblks);
+	if (left_seblks) {
+		/* If line is not fully erased, erase it */
+		if (atomic_read(&new->left_eblks)) {
+			if (pblk_line_erase(pblk, new))
+				goto out;
+		} else {
+			io_schedule();
+		}
+		goto retry_erase;
+	}
+
+	if (pblk_line_alloc_bitmaps(pblk, new))
+		return NULL;
+
+retry_setup:
+	if (!pblk_line_init_metadata(pblk, new, cur)) {
+		new = pblk_line_retry(pblk, new);
+		if (!new)
+			goto out;
+
+		goto retry_setup;
+	}
+
+	if (!pblk_line_init_bb(pblk, new, 1)) {
+		new = pblk_line_retry(pblk, new);
+		if (!new)
+			goto out;
+
+		goto retry_setup;
+	}
+
+	pblk_rl_free_lines_dec(&pblk->rl, new, true);
+
+	/* Allocate next line for preparation */
+	spin_lock(&l_mg->free_lock);
+	l_mg->data_next = pblk_line_get(pblk);
+	if (!l_mg->data_next) {
+		/* If we cannot get a new line, we need to stop the pipeline.
+		 * Only allow as many writes in as we can store safely and then
+		 * fail gracefully
+		 */
+		pblk_stop_writes(pblk, new);
+		l_mg->data_next = NULL;
+	} else {
+		l_mg->data_next->seq_nr = l_mg->d_seq_nr++;
+		l_mg->data_next->type = PBLK_LINETYPE_DATA;
+	}
+	spin_unlock(&l_mg->free_lock);
+
+out:
+	return new;
+}
+
+static void __pblk_line_put(struct pblk *pblk, struct pblk_line *line)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_gc *gc = &pblk->gc;
+
+	spin_lock(&line->lock);
+	WARN_ON(line->state != PBLK_LINESTATE_GC);
+	line->state = PBLK_LINESTATE_FREE;
+	line->gc_group = PBLK_LINEGC_NONE;
+	pblk_line_free(line);
+
+	if (line->w_err_gc->has_write_err) {
+		pblk_rl_werr_line_out(&pblk->rl);
+		line->w_err_gc->has_write_err = 0;
+	}
+
+	spin_unlock(&line->lock);
+	atomic_dec(&gc->pipeline_gc);
+
+	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);
+}
+
+static void pblk_line_put_ws(struct work_struct *work)
+{
+	struct pblk_line_ws *line_put_ws = container_of(work,
+						struct pblk_line_ws, ws);
+	struct pblk *pblk = line_put_ws->pblk;
+	struct pblk_line *line = line_put_ws->line;
+
+	__pblk_line_put(pblk, line);
+	mempool_free(line_put_ws, &pblk->gen_ws_pool);
+}
+
+void pblk_line_put(struct kref *ref)
+{
+	struct pblk_line *line = container_of(ref, struct pblk_line, ref);
+	struct pblk *pblk = line->pblk;
+
+	__pblk_line_put(pblk, line);
+}
+
+void pblk_line_put_wq(struct kref *ref)
+{
+	struct pblk_line *line = container_of(ref, struct pblk_line, ref);
+	struct pblk *pblk = line->pblk;
+	struct pblk_line_ws *line_put_ws;
+
+	line_put_ws = mempool_alloc(&pblk->gen_ws_pool, GFP_ATOMIC);
+	if (!line_put_ws)
+		return;
+
+	line_put_ws->pblk = pblk;
+	line_put_ws->line = line;
+	line_put_ws->priv = NULL;
+
+	INIT_WORK(&line_put_ws->ws, pblk_line_put_ws);
+	queue_work(pblk->r_end_wq, &line_put_ws->ws);
+}
+
+int pblk_blk_erase_async(struct pblk *pblk, struct ppa_addr ppa)
+{
+	struct nvm_rq *rqd;
+	int err;
+
+	rqd = pblk_alloc_rqd(pblk, PBLK_ERASE);
+
+	pblk_setup_e_rq(pblk, rqd, ppa);
+
+	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;
+
+		pblk_err(pblk, "could not async erase line:%d,blk:%d\n",
+					pblk_ppa_to_line(ppa),
+					pblk_ppa_to_pos(geo, ppa));
+	}
+
+	return err;
+}
+
+struct pblk_line *pblk_line_get_data(struct pblk *pblk)
+{
+	return pblk->l_mg.data_line;
+}
+
+/* For now, always erase next line */
+struct pblk_line *pblk_line_get_erase(struct pblk *pblk)
+{
+	return pblk->l_mg.data_next;
+}
+
+int pblk_line_is_full(struct pblk_line *line)
+{
+	return (line->left_msecs == 0);
+}
+
+static void pblk_line_should_sync_meta(struct pblk *pblk)
+{
+	if (pblk_rl_is_limit(&pblk->rl))
+		pblk_line_close_meta_sync(pblk);
+}
+
+void pblk_line_close(struct pblk *pblk, struct pblk_line *line)
+{
+	struct 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 list_head *move_list;
+	int i;
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	WARN(!bitmap_full(line->map_bitmap, lm->sec_per_line),
+				"pblk: corrupt closed line %d\n", line->id);
+#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(&l_mg->gc_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);
+
+	list_add_tail(&line->list, move_list);
+
+	kfree(line->map_bitmap);
+	line->map_bitmap = NULL;
+	line->smeta = NULL;
+	line->emeta = NULL;
+
+	for (i = 0; i < lm->blk_per_line; i++) {
+		struct pblk_lun *rlun = &pblk->luns[i];
+		int pos = pblk_ppa_to_pos(geo, rlun->bppa);
+		int state = line->chks[pos].state;
+
+		if (!(state & NVM_CHK_ST_OFFLINE))
+			state = NVM_CHK_ST_CLOSED;
+	}
+
+	spin_unlock(&line->lock);
+	spin_unlock(&l_mg->gc_lock);
+}
+
+void pblk_line_close_meta(struct pblk *pblk, struct pblk_line *line)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_emeta *emeta = line->emeta;
+	struct line_emeta *emeta_buf = emeta->buf;
+	struct wa_counters *wa = emeta_to_wa(lm, emeta_buf);
+
+	/* No need for exact vsc value; avoid a big line lock and take aprox. */
+	memcpy(emeta_to_vsc(pblk, emeta_buf), l_mg->vsc_list, lm->vsc_list_len);
+	memcpy(emeta_to_bb(emeta_buf), line->blk_bitmap, lm->blk_bitmap_len);
+
+	wa->user = cpu_to_le64(atomic64_read(&pblk->user_wa));
+	wa->pad = cpu_to_le64(atomic64_read(&pblk->pad_wa));
+	wa->gc = cpu_to_le64(atomic64_read(&pblk->gc_wa));
+
+	if (le32_to_cpu(emeta_buf->header.identifier) != PBLK_MAGIC) {
+		emeta_buf->header.identifier = cpu_to_le32(PBLK_MAGIC);
+		memcpy(emeta_buf->header.uuid, pblk->instance_uuid, 16);
+		emeta_buf->header.id = cpu_to_le32(line->id);
+		emeta_buf->header.type = cpu_to_le16(line->type);
+		emeta_buf->header.version_major = EMETA_VERSION_MAJOR;
+		emeta_buf->header.version_minor = EMETA_VERSION_MINOR;
+		emeta_buf->header.crc = cpu_to_le32(
+			pblk_calc_meta_header_crc(pblk, &emeta_buf->header));
+	}
+
+	emeta_buf->nr_valid_lbas = cpu_to_le64(line->nr_valid_lbas);
+	emeta_buf->crc = cpu_to_le32(pblk_calc_emeta_crc(pblk, emeta_buf));
+
+	spin_lock(&l_mg->close_lock);
+	spin_lock(&line->lock);
+
+	/* Update the in-memory start address for emeta, in case it has
+	 * shifted due to write errors
+	 */
+	if (line->emeta_ssec != line->cur_sec)
+		line->emeta_ssec = line->cur_sec;
+
+	list_add_tail(&line->list, &l_mg->emeta_list);
+	spin_unlock(&line->lock);
+	spin_unlock(&l_mg->close_lock);
+
+	pblk_line_should_sync_meta(pblk);
+}
+
+static void pblk_save_lba_list(struct pblk *pblk, struct pblk_line *line)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	unsigned int lba_list_size = lm->emeta_len[2];
+	struct pblk_w_err_gc *w_err_gc = line->w_err_gc;
+	struct pblk_emeta *emeta = line->emeta;
+
+	w_err_gc->lba_list = pblk_malloc(lba_list_size,
+					 l_mg->emeta_alloc_type, GFP_KERNEL);
+	memcpy(w_err_gc->lba_list, emeta_to_lbas(pblk, emeta->buf),
+				lba_list_size);
+}
+
+void pblk_line_close_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->line;
+	struct pblk_w_err_gc *w_err_gc = line->w_err_gc;
+
+	/* Write errors makes the emeta start address stored in smeta invalid,
+	 * so keep a copy of the lba list until we've gc'd the line
+	 */
+	if (w_err_gc->has_write_err)
+		pblk_save_lba_list(pblk, line);
+
+	pblk_line_close(pblk, line);
+	mempool_free(line_ws, &pblk->gen_ws_pool);
+}
+
+void pblk_gen_run_ws(struct pblk *pblk, struct pblk_line *line, void *priv,
+		      void (*work)(struct work_struct *), gfp_t gfp_mask,
+		      struct workqueue_struct *wq)
+{
+	struct pblk_line_ws *line_ws;
+
+	line_ws = mempool_alloc(&pblk->gen_ws_pool, gfp_mask);
+
+	line_ws->pblk = pblk;
+	line_ws->line = line;
+	line_ws->priv = priv;
+
+	INIT_WORK(&line_ws->ws, work);
+	queue_work(wq, &line_ws->ws);
+}
+
+static void __pblk_down_page(struct pblk *pblk, struct ppa_addr *ppa_list,
+			     int nr_ppas, int pos)
+{
+	struct pblk_lun *rlun = &pblk->luns[pos];
+	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_PBLK_DEBUG
+	int i;
+
+	for (i = 1; i < nr_ppas; i++)
+		WARN_ON(ppa_list[0].a.lun != ppa_list[i].a.lun ||
+				ppa_list[0].a.ch != ppa_list[i].a.ch);
+#endif
+
+	ret = down_timeout(&rlun->wr_sem, msecs_to_jiffies(30000));
+	if (ret == -ETIME || ret == -EINTR)
+		pblk_err(pblk, "taking lun semaphore timed out: err %d\n",
+				-ret);
+}
+
+void pblk_down_page(struct pblk *pblk, struct ppa_addr *ppa_list, int nr_ppas)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	int pos = pblk_ppa_to_pos(geo, ppa_list[0]);
+
+	__pblk_down_page(pblk, ppa_list, nr_ppas, pos);
+}
+
+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;
+	int pos = pblk_ppa_to_pos(geo, ppa_list[0]);
+
+	/* If the LUN has been locked for this same request, do no attempt to
+	 * lock it again
+	 */
+	if (test_and_set_bit(pos, lun_bitmap))
+		return;
+
+	__pblk_down_page(pblk, ppa_list, nr_ppas, pos);
+}
+
+void pblk_up_page(struct pblk *pblk, struct ppa_addr *ppa_list, int nr_ppas)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_lun *rlun;
+	int pos = pblk_ppa_to_pos(geo, ppa_list[0]);
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	int i;
+
+	for (i = 1; i < nr_ppas; i++)
+		WARN_ON(ppa_list[0].a.lun != ppa_list[i].a.lun ||
+				ppa_list[0].a.ch != ppa_list[i].a.ch);
+#endif
+
+	rlun = &pblk->luns[pos];
+	up(&rlun->wr_sem);
+}
+
+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 num_lun = geo->all_luns;
+	int bit = -1;
+
+	while ((bit = find_next_bit(lun_bitmap, num_lun, bit + 1)) < num_lun) {
+		rlun = &pblk->luns[bit];
+		up(&rlun->wr_sem);
+	}
+}
+
+void pblk_update_map(struct pblk *pblk, sector_t lba, struct ppa_addr ppa)
+{
+	struct ppa_addr ppa_l2p;
+
+	/* logic error: lba out-of-bounds. Ignore update */
+	if (!(lba < pblk->rl.nr_secs)) {
+		WARN(1, "pblk: corrupted L2P map request\n");
+		return;
+	}
+
+	spin_lock(&pblk->trans_lock);
+	ppa_l2p = pblk_trans_map_get(pblk, lba);
+
+	if (!pblk_addr_in_cache(ppa_l2p) && !pblk_ppa_empty(ppa_l2p))
+		pblk_map_invalidate(pblk, ppa_l2p);
+
+	pblk_trans_map_set(pblk, lba, ppa);
+	spin_unlock(&pblk->trans_lock);
+}
+
+void pblk_update_map_cache(struct pblk *pblk, sector_t lba, struct ppa_addr ppa)
+{
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	/* Callers must ensure that the ppa points to a cache address */
+	BUG_ON(!pblk_addr_in_cache(ppa));
+	BUG_ON(pblk_rb_pos_oob(&pblk->rwb, pblk_addr_to_cacheline(ppa)));
+#endif
+
+	pblk_update_map(pblk, lba, ppa);
+}
+
+int pblk_update_map_gc(struct pblk *pblk, sector_t lba, struct ppa_addr ppa_new,
+		       struct pblk_line *gc_line, u64 paddr_gc)
+{
+	struct ppa_addr ppa_l2p, ppa_gc;
+	int ret = 1;
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	/* Callers must ensure that the ppa points to a cache address */
+	BUG_ON(!pblk_addr_in_cache(ppa_new));
+	BUG_ON(pblk_rb_pos_oob(&pblk->rwb, pblk_addr_to_cacheline(ppa_new)));
+#endif
+
+	/* logic error: lba out-of-bounds. Ignore update */
+	if (!(lba < pblk->rl.nr_secs)) {
+		WARN(1, "pblk: corrupted L2P map request\n");
+		return 0;
+	}
+
+	spin_lock(&pblk->trans_lock);
+	ppa_l2p = pblk_trans_map_get(pblk, lba);
+	ppa_gc = addr_to_gen_ppa(pblk, paddr_gc, gc_line->id);
+
+	if (!pblk_ppa_comp(ppa_l2p, ppa_gc)) {
+		spin_lock(&gc_line->lock);
+		WARN(!test_bit(paddr_gc, gc_line->invalid_bitmap),
+						"pblk: corrupted GC update");
+		spin_unlock(&gc_line->lock);
+
+		ret = 0;
+		goto out;
+	}
+
+	pblk_trans_map_set(pblk, lba, ppa_new);
+out:
+	spin_unlock(&pblk->trans_lock);
+	return ret;
+}
+
+void pblk_update_map_dev(struct pblk *pblk, sector_t lba,
+			 struct ppa_addr ppa_mapped, struct ppa_addr ppa_cache)
+{
+	struct ppa_addr ppa_l2p;
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	/* Callers must ensure that the ppa points to a device address */
+	BUG_ON(pblk_addr_in_cache(ppa_mapped));
+#endif
+	/* Invalidate and discard padded entries */
+	if (lba == ADDR_EMPTY) {
+		atomic64_inc(&pblk->pad_wa);
+#ifdef CONFIG_NVM_PBLK_DEBUG
+		atomic_long_inc(&pblk->padded_wb);
+#endif
+		if (!pblk_ppa_empty(ppa_mapped))
+			pblk_map_invalidate(pblk, ppa_mapped);
+		return;
+	}
+
+	/* logic error: lba out-of-bounds. Ignore update */
+	if (!(lba < pblk->rl.nr_secs)) {
+		WARN(1, "pblk: corrupted L2P map request\n");
+		return;
+	}
+
+	spin_lock(&pblk->trans_lock);
+	ppa_l2p = pblk_trans_map_get(pblk, lba);
+
+	/* Do not update L2P if the cacheline has been updated. In this case,
+	 * the mapped ppa must be invalidated
+	 */
+	if (!pblk_ppa_comp(ppa_l2p, ppa_cache)) {
+		if (!pblk_ppa_empty(ppa_mapped))
+			pblk_map_invalidate(pblk, ppa_mapped);
+		goto out;
+	}
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	WARN_ON(!pblk_addr_in_cache(ppa_l2p) && !pblk_ppa_empty(ppa_l2p));
+#endif
+
+	pblk_trans_map_set(pblk, lba, ppa_mapped);
+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++) {
+		struct ppa_addr ppa;
+
+		ppa = ppas[i] = pblk_trans_map_get(pblk, blba + i);
+
+		/* If the L2P entry maps to a line, the reference is valid */
+		if (!pblk_ppa_empty(ppa) && !pblk_addr_in_cache(ppa)) {
+			int line_id = pblk_ppa_to_line(ppa);
+			struct pblk_line *line = &pblk->lines[line_id];
+
+			kref_get(&line->ref);
+		}
+	}
+	spin_unlock(&pblk->trans_lock);
+}
+
+void pblk_lookup_l2p_rand(struct pblk *pblk, struct ppa_addr *ppas,
+			  u64 *lba_list, int nr_secs)
+{
+	u64 lba;
+	int i;
+
+	spin_lock(&pblk->trans_lock);
+	for (i = 0; i < nr_secs; i++) {
+		lba = lba_list[i];
+		if (lba != ADDR_EMPTY) {
+			/* logic error: lba out-of-bounds. Ignore update */
+			if (!(lba < pblk->rl.nr_secs)) {
+				WARN(1, "pblk: corrupted L2P map request\n");
+				continue;
+			}
+			ppas[i] = pblk_trans_map_get(pblk, lba);
+		}
+	}
+	spin_unlock(&pblk->trans_lock);
+}
diff --git a/src/kernel/linux/v4.19/drivers/lightnvm/pblk-gc.c b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-gc.c
new file mode 100644
index 0000000..157c256
--- /dev/null
+++ b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-gc.c
@@ -0,0 +1,705 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@cnexlabs.com>
+ *                  Matias Bjorling <matias@cnexlabs.com>
+ *
+ * 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"
+#include <linux/delay.h>
+
+static void pblk_gc_free_gc_rq(struct pblk_gc_rq *gc_rq)
+{
+	if (gc_rq->data)
+		vfree(gc_rq->data);
+	kfree(gc_rq);
+}
+
+static int pblk_gc_write(struct pblk *pblk)
+{
+	struct pblk_gc *gc = &pblk->gc;
+	struct pblk_gc_rq *gc_rq, *tgc_rq;
+	LIST_HEAD(w_list);
+
+	spin_lock(&gc->w_lock);
+	if (list_empty(&gc->w_list)) {
+		spin_unlock(&gc->w_lock);
+		return 1;
+	}
+
+	list_cut_position(&w_list, &gc->w_list, gc->w_list.prev);
+	gc->w_entries = 0;
+	spin_unlock(&gc->w_lock);
+
+	list_for_each_entry_safe(gc_rq, tgc_rq, &w_list, list) {
+		pblk_write_gc_to_cache(pblk, gc_rq);
+		list_del(&gc_rq->list);
+		kref_put(&gc_rq->line->ref, pblk_line_put);
+		pblk_gc_free_gc_rq(gc_rq);
+	}
+
+	return 0;
+}
+
+static void pblk_gc_writer_kick(struct pblk_gc *gc)
+{
+	wake_up_process(gc->gc_writer_ts);
+}
+
+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;
+
+	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 *gc_rq_ws = container_of(work,
+						struct pblk_line_ws, ws);
+	struct pblk *pblk = gc_rq_ws->pblk;
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_gc *gc = &pblk->gc;
+	struct pblk_line *line = gc_rq_ws->line;
+	struct pblk_gc_rq *gc_rq = gc_rq_ws->priv;
+	int ret;
+
+	up(&gc->gc_sem);
+
+	gc_rq->data = vmalloc(array_size(gc_rq->nr_secs, geo->csecs));
+	if (!gc_rq->data) {
+		pblk_err(pblk, "could not GC line:%d (%d/%d)\n",
+					line->id, *line->vsc, gc_rq->nr_secs);
+		goto out;
+	}
+
+	/* Read from GC victim block */
+	ret = pblk_submit_read_gc(pblk, gc_rq);
+	if (ret) {
+		pblk_err(pblk, "failed GC read in line:%d (err:%d)\n",
+								line->id, ret);
+		goto out;
+	}
+
+	if (!gc_rq->secs_to_gc)
+		goto out;
+
+retry:
+	spin_lock(&gc->w_lock);
+	if (gc->w_entries >= PBLK_GC_RQ_QD) {
+		spin_unlock(&gc->w_lock);
+		pblk_gc_writer_kick(&pblk->gc);
+		usleep_range(128, 256);
+		goto retry;
+	}
+	gc->w_entries++;
+	list_add_tail(&gc_rq->list, &gc->w_list);
+	spin_unlock(&gc->w_lock);
+
+	pblk_gc_writer_kick(&pblk->gc);
+
+	kfree(gc_rq_ws);
+	return;
+
+out:
+	pblk_gc_free_gc_rq(gc_rq);
+	kref_put(&line->ref, pblk_line_put);
+	kfree(gc_rq_ws);
+}
+
+static __le64 *get_lba_list_from_emeta(struct pblk *pblk,
+				       struct pblk_line *line)
+{
+	struct line_emeta *emeta_buf;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line_meta *lm = &pblk->lm;
+	unsigned int lba_list_size = lm->emeta_len[2];
+	__le64 *lba_list;
+	int ret;
+
+	emeta_buf = pblk_malloc(lm->emeta_len[0],
+				l_mg->emeta_alloc_type, GFP_KERNEL);
+	if (!emeta_buf)
+		return NULL;
+
+	ret = pblk_line_read_emeta(pblk, line, emeta_buf);
+	if (ret) {
+		pblk_err(pblk, "line %d read emeta failed (%d)\n",
+				line->id, ret);
+		pblk_mfree(emeta_buf, l_mg->emeta_alloc_type);
+		return NULL;
+	}
+
+	/* 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.
+	 */
+
+	ret = pblk_recov_check_emeta(pblk, emeta_buf);
+	if (ret) {
+		pblk_err(pblk, "inconsistent emeta (line %d)\n",
+				line->id);
+		pblk_mfree(emeta_buf, l_mg->emeta_alloc_type);
+		return NULL;
+	}
+
+	lba_list = pblk_malloc(lba_list_size,
+			       l_mg->emeta_alloc_type, GFP_KERNEL);
+	if (lba_list)
+		memcpy(lba_list, emeta_to_lbas(pblk, emeta_buf), lba_list_size);
+
+	pblk_mfree(emeta_buf, l_mg->emeta_alloc_type);
+
+	return lba_list;
+}
+
+static void pblk_gc_line_prepare_ws(struct work_struct *work)
+{
+	struct pblk_line_ws *line_ws = container_of(work, struct pblk_line_ws,
+									ws);
+	struct pblk *pblk = line_ws->pblk;
+	struct pblk_line *line = line_ws->line;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_gc *gc = &pblk->gc;
+	struct pblk_line_ws *gc_rq_ws;
+	struct pblk_gc_rq *gc_rq;
+	__le64 *lba_list;
+	unsigned long *invalid_bitmap;
+	int sec_left, nr_secs, bit;
+
+	invalid_bitmap = kmalloc(lm->sec_bitmap_len, GFP_KERNEL);
+	if (!invalid_bitmap)
+		goto fail_free_ws;
+
+	if (line->w_err_gc->has_write_err) {
+		lba_list = line->w_err_gc->lba_list;
+		line->w_err_gc->lba_list = NULL;
+	} else {
+		lba_list = get_lba_list_from_emeta(pblk, line);
+		if (!lba_list) {
+			pblk_err(pblk, "could not interpret emeta (line %d)\n",
+					line->id);
+			goto fail_free_invalid_bitmap;
+		}
+	}
+
+	spin_lock(&line->lock);
+	bitmap_copy(invalid_bitmap, line->invalid_bitmap, lm->sec_per_line);
+	sec_left = pblk_line_vsc(line);
+	spin_unlock(&line->lock);
+
+	if (sec_left < 0) {
+		pblk_err(pblk, "corrupted GC line (%d)\n", line->id);
+		goto fail_free_lba_list;
+	}
+
+	bit = -1;
+next_rq:
+	gc_rq = kmalloc(sizeof(struct pblk_gc_rq), GFP_KERNEL);
+	if (!gc_rq)
+		goto fail_free_lba_list;
+
+	nr_secs = 0;
+	do {
+		bit = find_next_zero_bit(invalid_bitmap, lm->sec_per_line,
+								bit + 1);
+		if (bit > line->emeta_ssec)
+			break;
+
+		gc_rq->paddr_list[nr_secs] = bit;
+		gc_rq->lba_list[nr_secs++] = le64_to_cpu(lba_list[bit]);
+	} while (nr_secs < pblk->max_write_pgs);
+
+	if (unlikely(!nr_secs)) {
+		kfree(gc_rq);
+		goto out;
+	}
+
+	gc_rq->nr_secs = nr_secs;
+	gc_rq->line = line;
+
+	gc_rq_ws = kmalloc(sizeof(struct pblk_line_ws), GFP_KERNEL);
+	if (!gc_rq_ws)
+		goto fail_free_gc_rq;
+
+	gc_rq_ws->pblk = pblk;
+	gc_rq_ws->line = line;
+	gc_rq_ws->priv = gc_rq;
+
+	/* The write GC path can be much slower than the read GC one due to
+	 * the budget imposed by the rate-limiter. Balance in case that we get
+	 * back pressure from the write GC path.
+	 */
+	while (down_timeout(&gc->gc_sem, msecs_to_jiffies(30000)))
+		io_schedule();
+
+	kref_get(&line->ref);
+
+	INIT_WORK(&gc_rq_ws->ws, pblk_gc_line_ws);
+	queue_work(gc->gc_line_reader_wq, &gc_rq_ws->ws);
+
+	sec_left -= nr_secs;
+	if (sec_left > 0)
+		goto next_rq;
+
+out:
+	pblk_mfree(lba_list, l_mg->emeta_alloc_type);
+	kfree(line_ws);
+	kfree(invalid_bitmap);
+
+	kref_put(&line->ref, pblk_line_put);
+	atomic_dec(&gc->read_inflight_gc);
+
+	return;
+
+fail_free_gc_rq:
+	kfree(gc_rq);
+fail_free_lba_list:
+	pblk_mfree(lba_list, l_mg->emeta_alloc_type);
+fail_free_invalid_bitmap:
+	kfree(invalid_bitmap);
+fail_free_ws:
+	kfree(line_ws);
+
+	pblk_put_line_back(pblk, line);
+	kref_put(&line->ref, pblk_line_put);
+	atomic_dec(&gc->read_inflight_gc);
+
+	pblk_err(pblk, "failed to GC line %d\n", line->id);
+}
+
+static int pblk_gc_line(struct pblk *pblk, struct pblk_line *line)
+{
+	struct pblk_gc *gc = &pblk->gc;
+	struct pblk_line_ws *line_ws;
+
+	pblk_debug(pblk, "line '%d' being reclaimed for GC\n", line->id);
+
+	line_ws = kmalloc(sizeof(struct pblk_line_ws), GFP_KERNEL);
+	if (!line_ws)
+		return -ENOMEM;
+
+	line_ws->pblk = pblk;
+	line_ws->line = line;
+
+	atomic_inc(&gc->pipeline_gc);
+	INIT_WORK(&line_ws->ws, pblk_gc_line_prepare_ws);
+	queue_work(gc->gc_reader_wq, &line_ws->ws);
+
+	return 0;
+}
+
+static void pblk_gc_reader_kick(struct pblk_gc *gc)
+{
+	wake_up_process(gc->gc_reader_ts);
+}
+
+static void pblk_gc_kick(struct pblk *pblk)
+{
+	struct pblk_gc *gc = &pblk->gc;
+
+	pblk_gc_writer_kick(gc);
+	pblk_gc_reader_kick(gc);
+
+	/* If we're shutting down GC, let's not start it up again */
+	if (gc->gc_enabled) {
+		wake_up_process(gc->gc_ts);
+		mod_timer(&gc->gc_timer,
+			  jiffies + msecs_to_jiffies(GC_TIME_MSECS));
+	}
+}
+
+static int pblk_gc_read(struct pblk *pblk)
+{
+	struct pblk_gc *gc = &pblk->gc;
+	struct pblk_line *line;
+
+	spin_lock(&gc->r_lock);
+	if (list_empty(&gc->r_list)) {
+		spin_unlock(&gc->r_lock);
+		return 1;
+	}
+
+	line = list_first_entry(&gc->r_list, struct pblk_line, list);
+	list_del(&line->list);
+	spin_unlock(&gc->r_lock);
+
+	pblk_gc_kick(pblk);
+
+	if (pblk_gc_line(pblk, line))
+		pblk_err(pblk, "failed to GC line %d\n", line->id);
+
+	return 0;
+}
+
+static struct pblk_line *pblk_gc_get_victim_line(struct pblk *pblk,
+						 struct list_head *group_list)
+{
+	struct pblk_line *line, *victim;
+	int line_vsc, victim_vsc;
+
+	victim = list_first_entry(group_list, struct pblk_line, list);
+	list_for_each_entry(line, group_list, list) {
+		line_vsc = le32_to_cpu(*line->vsc);
+		victim_vsc = le32_to_cpu(*victim->vsc);
+		if (line_vsc < victim_vsc)
+			victim = line;
+	}
+
+	return victim;
+}
+
+static bool pblk_gc_should_run(struct pblk_gc *gc, struct pblk_rl *rl)
+{
+	unsigned int nr_blocks_free, nr_blocks_need;
+	unsigned int werr_lines = atomic_read(&rl->werr_lines);
+
+	nr_blocks_need = pblk_rl_high_thrs(rl);
+	nr_blocks_free = pblk_rl_nr_free_blks(rl);
+
+	/* This is not critical, no need to take lock here */
+	return ((werr_lines > 0) ||
+		((gc->gc_active) && (nr_blocks_need > nr_blocks_free)));
+}
+
+void pblk_gc_free_full_lines(struct pblk *pblk)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_gc *gc = &pblk->gc;
+	struct pblk_line *line;
+
+	do {
+		spin_lock(&l_mg->gc_lock);
+		if (list_empty(&l_mg->gc_full_list)) {
+			spin_unlock(&l_mg->gc_lock);
+			return;
+		}
+
+		line = list_first_entry(&l_mg->gc_full_list,
+							struct pblk_line, list);
+
+		spin_lock(&line->lock);
+		WARN_ON(line->state != PBLK_LINESTATE_CLOSED);
+		line->state = PBLK_LINESTATE_GC;
+		spin_unlock(&line->lock);
+
+		list_del(&line->list);
+		spin_unlock(&l_mg->gc_lock);
+
+		atomic_inc(&gc->pipeline_gc);
+		kref_put(&line->ref, pblk_line_put);
+	} while (1);
+}
+
+/*
+ * Lines with no valid sectors will be returned to the free list immediately. If
+ * GC is activated - either because the free block count is under the determined
+ * threshold, or because it is being forced from user space - only lines with a
+ * high count of invalid sectors will be recycled.
+ */
+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;
+	struct list_head *group_list;
+	bool run_gc;
+	int read_inflight_gc, gc_group = 0, prev_group = 0;
+
+	pblk_gc_free_full_lines(pblk);
+
+	run_gc = pblk_gc_should_run(&pblk->gc, &pblk->rl);
+	if (!run_gc || (atomic_read(&gc->read_inflight_gc) >= PBLK_GC_L_QD))
+		return;
+
+next_gc_group:
+	group_list = l_mg->gc_lists[gc_group++];
+
+	do {
+		spin_lock(&l_mg->gc_lock);
+		if (list_empty(group_list)) {
+			spin_unlock(&l_mg->gc_lock);
+			break;
+		}
+
+		line = pblk_gc_get_victim_line(pblk, group_list);
+
+		spin_lock(&line->lock);
+		WARN_ON(line->state != PBLK_LINESTATE_CLOSED);
+		line->state = PBLK_LINESTATE_GC;
+		spin_unlock(&line->lock);
+
+		list_del(&line->list);
+		spin_unlock(&l_mg->gc_lock);
+
+		spin_lock(&gc->r_lock);
+		list_add_tail(&line->list, &gc->r_list);
+		spin_unlock(&gc->r_lock);
+
+		read_inflight_gc = atomic_inc_return(&gc->read_inflight_gc);
+		pblk_gc_reader_kick(gc);
+
+		prev_group = 1;
+
+		/* No need to queue up more GC lines than we can handle */
+		run_gc = pblk_gc_should_run(&pblk->gc, &pblk->rl);
+		if (!run_gc || read_inflight_gc >= PBLK_GC_L_QD)
+			break;
+	} while (1);
+
+	if (!prev_group && pblk->rl.rb_state > gc_group &&
+						gc_group < PBLK_GC_NR_LISTS)
+		goto next_gc_group;
+}
+
+static void pblk_gc_timer(struct timer_list *t)
+{
+	struct pblk *pblk = from_timer(pblk, t, gc.gc_timer);
+
+	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 int pblk_gc_writer_ts(void *data)
+{
+	struct pblk *pblk = data;
+
+	while (!kthread_should_stop()) {
+		if (!pblk_gc_write(pblk))
+			continue;
+		set_current_state(TASK_INTERRUPTIBLE);
+		io_schedule();
+	}
+
+	return 0;
+}
+
+static int pblk_gc_reader_ts(void *data)
+{
+	struct pblk *pblk = data;
+	struct pblk_gc *gc = &pblk->gc;
+
+	while (!kthread_should_stop()) {
+		if (!pblk_gc_read(pblk))
+			continue;
+		set_current_state(TASK_INTERRUPTIBLE);
+		io_schedule();
+	}
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	pblk_info(pblk, "flushing gc pipeline, %d lines left\n",
+		atomic_read(&gc->pipeline_gc));
+#endif
+
+	do {
+		if (!atomic_read(&gc->pipeline_gc))
+			break;
+
+		schedule();
+	} while (1);
+
+	return 0;
+}
+
+static void pblk_gc_start(struct pblk *pblk)
+{
+	pblk->gc.gc_active = 1;
+	pblk_debug(pblk, "gc start\n");
+}
+
+void pblk_gc_should_start(struct pblk *pblk)
+{
+	struct pblk_gc *gc = &pblk->gc;
+
+	if (gc->gc_enabled && !gc->gc_active) {
+		pblk_gc_start(pblk);
+		pblk_gc_kick(pblk);
+	}
+}
+
+void pblk_gc_should_stop(struct pblk *pblk)
+{
+	struct pblk_gc *gc = &pblk->gc;
+
+	if (gc->gc_active && !gc->gc_forced)
+		gc->gc_active = 0;
+}
+
+void pblk_gc_should_kick(struct pblk *pblk)
+{
+	pblk_rl_update_rates(&pblk->rl);
+}
+
+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);
+}
+
+int pblk_gc_sysfs_force(struct pblk *pblk, int force)
+{
+	struct pblk_gc *gc = &pblk->gc;
+
+	if (force < 0 || force > 1)
+		return -EINVAL;
+
+	spin_lock(&gc->lock);
+	gc->gc_forced = force;
+
+	if (force)
+		gc->gc_enabled = 1;
+	else
+		gc->gc_enabled = 0;
+	spin_unlock(&gc->lock);
+
+	pblk_gc_should_start(pblk);
+
+	return 0;
+}
+
+int pblk_gc_init(struct pblk *pblk)
+{
+	struct pblk_gc *gc = &pblk->gc;
+	int ret;
+
+	gc->gc_ts = kthread_create(pblk_gc_ts, pblk, "pblk-gc-ts");
+	if (IS_ERR(gc->gc_ts)) {
+		pblk_err(pblk, "could not allocate GC main kthread\n");
+		return PTR_ERR(gc->gc_ts);
+	}
+
+	gc->gc_writer_ts = kthread_create(pblk_gc_writer_ts, pblk,
+							"pblk-gc-writer-ts");
+	if (IS_ERR(gc->gc_writer_ts)) {
+		pblk_err(pblk, "could not allocate GC writer kthread\n");
+		ret = PTR_ERR(gc->gc_writer_ts);
+		goto fail_free_main_kthread;
+	}
+
+	gc->gc_reader_ts = kthread_create(pblk_gc_reader_ts, pblk,
+							"pblk-gc-reader-ts");
+	if (IS_ERR(gc->gc_reader_ts)) {
+		pblk_err(pblk, "could not allocate GC reader kthread\n");
+		ret = PTR_ERR(gc->gc_reader_ts);
+		goto fail_free_writer_kthread;
+	}
+
+	timer_setup(&gc->gc_timer, pblk_gc_timer, 0);
+	mod_timer(&gc->gc_timer, jiffies + msecs_to_jiffies(GC_TIME_MSECS));
+
+	gc->gc_active = 0;
+	gc->gc_forced = 0;
+	gc->gc_enabled = 1;
+	gc->w_entries = 0;
+	atomic_set(&gc->read_inflight_gc, 0);
+	atomic_set(&gc->pipeline_gc, 0);
+
+	/* Workqueue that reads valid sectors from a line and submit them to the
+	 * GC writer to be recycled.
+	 */
+	gc->gc_line_reader_wq = alloc_workqueue("pblk-gc-line-reader-wq",
+			WQ_MEM_RECLAIM | WQ_UNBOUND, PBLK_GC_MAX_READERS);
+	if (!gc->gc_line_reader_wq) {
+		pblk_err(pblk, "could not allocate GC line reader workqueue\n");
+		ret = -ENOMEM;
+		goto fail_free_reader_kthread;
+	}
+
+	/* Workqueue that prepare lines for GC */
+	gc->gc_reader_wq = alloc_workqueue("pblk-gc-line_wq",
+					WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
+	if (!gc->gc_reader_wq) {
+		pblk_err(pblk, "could not allocate GC reader workqueue\n");
+		ret = -ENOMEM;
+		goto fail_free_reader_line_wq;
+	}
+
+	spin_lock_init(&gc->lock);
+	spin_lock_init(&gc->w_lock);
+	spin_lock_init(&gc->r_lock);
+
+	sema_init(&gc->gc_sem, PBLK_GC_RQ_QD);
+
+	INIT_LIST_HEAD(&gc->w_list);
+	INIT_LIST_HEAD(&gc->r_list);
+
+	return 0;
+
+fail_free_reader_line_wq:
+	destroy_workqueue(gc->gc_line_reader_wq);
+fail_free_reader_kthread:
+	kthread_stop(gc->gc_reader_ts);
+fail_free_writer_kthread:
+	kthread_stop(gc->gc_writer_ts);
+fail_free_main_kthread:
+	kthread_stop(gc->gc_ts);
+
+	return ret;
+}
+
+void pblk_gc_exit(struct pblk *pblk, bool graceful)
+{
+	struct pblk_gc *gc = &pblk->gc;
+
+	gc->gc_enabled = 0;
+	del_timer_sync(&gc->gc_timer);
+	gc->gc_active = 0;
+
+	if (gc->gc_ts)
+		kthread_stop(gc->gc_ts);
+
+	if (gc->gc_reader_ts)
+		kthread_stop(gc->gc_reader_ts);
+
+	if (graceful) {
+		flush_workqueue(gc->gc_reader_wq);
+		flush_workqueue(gc->gc_line_reader_wq);
+	}
+
+	destroy_workqueue(gc->gc_reader_wq);
+	destroy_workqueue(gc->gc_line_reader_wq);
+
+	if (gc->gc_writer_ts)
+		kthread_stop(gc->gc_writer_ts);
+}
diff --git a/src/kernel/linux/v4.19/drivers/lightnvm/pblk-init.c b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-init.c
new file mode 100644
index 0000000..88b6327
--- /dev/null
+++ b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-init.c
@@ -0,0 +1,1366 @@
+/*
+ * Copyright (C) 2015 IT University of Copenhagen (rrpc.c)
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@cnexlabs.com>
+ *                  Matias Bjorling <matias@cnexlabs.com>
+ *
+ * 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.
+ */
+
+#include "pblk.h"
+
+static unsigned int write_buffer_size;
+
+module_param(write_buffer_size, uint, 0644);
+MODULE_PARM_DESC(write_buffer_size, "number of entries in a write buffer");
+
+static struct kmem_cache *pblk_ws_cache, *pblk_rec_cache, *pblk_g_rq_cache,
+				*pblk_w_rq_cache;
+static DECLARE_RWSEM(pblk_lock);
+struct bio_set pblk_bio_set;
+
+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);
+		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 (pblk_get_secs(bio) > pblk_rl_max_io(&pblk->rl))
+		blk_queue_split(q, &bio);
+
+	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 size_t pblk_trans_map_size(struct pblk *pblk)
+{
+	int entry_size = 8;
+
+	if (pblk->addrf_len < 32)
+		entry_size = 4;
+
+	return entry_size * pblk->rl.nr_secs;
+}
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+static u32 pblk_l2p_crc(struct pblk *pblk)
+{
+	size_t map_size;
+	u32 crc = ~(u32)0;
+
+	map_size = pblk_trans_map_size(pblk);
+	crc = crc32_le(crc, pblk->trans_map, map_size);
+	return crc;
+}
+#endif
+
+static void pblk_l2p_free(struct pblk *pblk)
+{
+	vfree(pblk->trans_map);
+}
+
+static int pblk_l2p_recover(struct pblk *pblk, bool factory_init)
+{
+	struct pblk_line *line = NULL;
+
+	if (factory_init) {
+		pblk_setup_uuid(pblk);
+	} else {
+		line = pblk_recov_l2p(pblk);
+		if (IS_ERR(line)) {
+			pblk_err(pblk, "could not recover l2p table\n");
+			return -EFAULT;
+		}
+	}
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	pblk_info(pblk, "init: L2P CRC: %x\n", pblk_l2p_crc(pblk));
+#endif
+
+	/* Free full lines directly as GC has not been started yet */
+	pblk_gc_free_full_lines(pblk);
+
+	if (!line) {
+		/* Configure next line for user data */
+		line = pblk_line_get_first_data(pblk);
+		if (!line)
+			return -EFAULT;
+	}
+
+	return 0;
+}
+
+static int pblk_l2p_init(struct pblk *pblk, bool factory_init)
+{
+	sector_t i;
+	struct ppa_addr ppa;
+	size_t map_size;
+	int ret = 0;
+
+	map_size = pblk_trans_map_size(pblk);
+	pblk->trans_map = vmalloc(map_size);
+	if (!pblk->trans_map)
+		return -ENOMEM;
+
+	pblk_ppa_set_empty(&ppa);
+
+	for (i = 0; i < pblk->rl.nr_secs; i++)
+		pblk_trans_map_set(pblk, i, ppa);
+
+	ret = pblk_l2p_recover(pblk, factory_init);
+	if (ret)
+		vfree(pblk->trans_map);
+
+	return ret;
+}
+
+static void pblk_rwb_free(struct pblk *pblk)
+{
+	if (pblk_rb_tear_down_check(&pblk->rwb))
+		pblk_err(pblk, "write buffer error on tear down\n");
+
+	pblk_rb_data_free(&pblk->rwb);
+	vfree(pblk_rb_entries_ref(&pblk->rwb));
+}
+
+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;
+	unsigned long nr_entries, buffer_size;
+	unsigned int power_size, power_seg_sz;
+	int pgs_in_buffer;
+
+	pgs_in_buffer = (max(geo->mw_cunits, geo->ws_opt) + geo->ws_opt)
+								* geo->all_luns;
+
+	if (write_buffer_size && (write_buffer_size > pgs_in_buffer))
+		buffer_size = write_buffer_size;
+	else
+		buffer_size = pgs_in_buffer;
+
+	nr_entries = pblk_rb_calculate_size(buffer_size);
+
+	entries = vzalloc(array_size(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->csecs);
+
+	return pblk_rb_init(&pblk->rwb, entries, power_size, power_seg_sz);
+}
+
+/* Minimum pages needed within a lun */
+#define ADDR_POOL_SIZE 64
+
+static int pblk_set_addrf_12(struct pblk *pblk, struct nvm_geo *geo,
+			     struct nvm_addrf_12 *dst)
+{
+	struct nvm_addrf_12 *src = (struct nvm_addrf_12 *)&geo->addrf;
+	int power_len;
+
+	/* Re-calculate channel and lun format to adapt to configuration */
+	power_len = get_count_order(geo->num_ch);
+	if (1 << power_len != geo->num_ch) {
+		pblk_err(pblk, "supports only power-of-two channel config.\n");
+		return -EINVAL;
+	}
+	dst->ch_len = power_len;
+
+	power_len = get_count_order(geo->num_lun);
+	if (1 << power_len != geo->num_lun) {
+		pblk_err(pblk, "supports only power-of-two LUN config.\n");
+		return -EINVAL;
+	}
+	dst->lun_len = power_len;
+
+	dst->blk_len = src->blk_len;
+	dst->pg_len = src->pg_len;
+	dst->pln_len = src->pln_len;
+	dst->sec_len = src->sec_len;
+
+	dst->sec_offset = 0;
+	dst->pln_offset = dst->sec_len;
+	dst->ch_offset = dst->pln_offset + dst->pln_len;
+	dst->lun_offset = dst->ch_offset + dst->ch_len;
+	dst->pg_offset = dst->lun_offset + dst->lun_len;
+	dst->blk_offset = dst->pg_offset + dst->pg_len;
+
+	dst->sec_mask = ((1ULL << dst->sec_len) - 1) << dst->sec_offset;
+	dst->pln_mask = ((1ULL << dst->pln_len) - 1) << dst->pln_offset;
+	dst->ch_mask = ((1ULL << dst->ch_len) - 1) << dst->ch_offset;
+	dst->lun_mask = ((1ULL << dst->lun_len) - 1) << dst->lun_offset;
+	dst->pg_mask = ((1ULL << dst->pg_len) - 1) << dst->pg_offset;
+	dst->blk_mask = ((1ULL << dst->blk_len) - 1) << dst->blk_offset;
+
+	return dst->blk_offset + src->blk_len;
+}
+
+static int pblk_set_addrf_20(struct nvm_geo *geo, struct nvm_addrf *adst,
+			     struct pblk_addrf *udst)
+{
+	struct nvm_addrf *src = &geo->addrf;
+
+	adst->ch_len = get_count_order(geo->num_ch);
+	adst->lun_len = get_count_order(geo->num_lun);
+	adst->chk_len = src->chk_len;
+	adst->sec_len = src->sec_len;
+
+	adst->sec_offset = 0;
+	adst->ch_offset = adst->sec_len;
+	adst->lun_offset = adst->ch_offset + adst->ch_len;
+	adst->chk_offset = adst->lun_offset + adst->lun_len;
+
+	adst->sec_mask = ((1ULL << adst->sec_len) - 1) << adst->sec_offset;
+	adst->chk_mask = ((1ULL << adst->chk_len) - 1) << adst->chk_offset;
+	adst->lun_mask = ((1ULL << adst->lun_len) - 1) << adst->lun_offset;
+	adst->ch_mask = ((1ULL << adst->ch_len) - 1) << adst->ch_offset;
+
+	udst->sec_stripe = geo->ws_opt;
+	udst->ch_stripe = geo->num_ch;
+	udst->lun_stripe = geo->num_lun;
+
+	udst->sec_lun_stripe = udst->sec_stripe * udst->ch_stripe;
+	udst->sec_ws_stripe = udst->sec_lun_stripe * udst->lun_stripe;
+
+	return adst->chk_offset + adst->chk_len;
+}
+
+static int pblk_set_addrf(struct pblk *pblk)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	int mod;
+
+	switch (geo->version) {
+	case NVM_OCSSD_SPEC_12:
+		div_u64_rem(geo->clba, pblk->min_write_pgs, &mod);
+		if (mod) {
+			pblk_err(pblk, "bad configuration of sectors/pages\n");
+			return -EINVAL;
+		}
+
+		pblk->addrf_len = pblk_set_addrf_12(pblk, geo,
+							(void *)&pblk->addrf);
+		break;
+	case NVM_OCSSD_SPEC_20:
+		pblk->addrf_len = pblk_set_addrf_20(geo, (void *)&pblk->addrf,
+							&pblk->uaddrf);
+		break;
+	default:
+		pblk_err(pblk, "OCSSD revision not supported (%d)\n",
+								geo->version);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int pblk_init_global_caches(struct pblk *pblk)
+{
+	down_write(&pblk_lock);
+	pblk_ws_cache = kmem_cache_create("pblk_blk_ws",
+				sizeof(struct pblk_line_ws), 0, 0, NULL);
+	if (!pblk_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_ws_cache);
+		up_write(&pblk_lock);
+		return -ENOMEM;
+	}
+
+	pblk_g_rq_cache = kmem_cache_create("pblk_g_rq", pblk_g_rq_size,
+				0, 0, NULL);
+	if (!pblk_g_rq_cache) {
+		kmem_cache_destroy(pblk_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_ws_cache);
+		kmem_cache_destroy(pblk_rec_cache);
+		kmem_cache_destroy(pblk_g_rq_cache);
+		up_write(&pblk_lock);
+		return -ENOMEM;
+	}
+	up_write(&pblk_lock);
+
+	return 0;
+}
+
+static void pblk_free_global_caches(struct pblk *pblk)
+{
+	kmem_cache_destroy(pblk_ws_cache);
+	kmem_cache_destroy(pblk_rec_cache);
+	kmem_cache_destroy(pblk_g_rq_cache);
+	kmem_cache_destroy(pblk_w_rq_cache);
+}
+
+static int pblk_core_init(struct pblk *pblk)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	int ret, max_write_ppas;
+
+	atomic64_set(&pblk->user_wa, 0);
+	atomic64_set(&pblk->pad_wa, 0);
+	atomic64_set(&pblk->gc_wa, 0);
+	pblk->user_rst_wa = 0;
+	pblk->pad_rst_wa = 0;
+	pblk->gc_rst_wa = 0;
+
+	atomic64_set(&pblk->nr_flush, 0);
+	pblk->nr_flush_rst = 0;
+
+	pblk->min_write_pgs = geo->ws_opt;
+	max_write_ppas = pblk->min_write_pgs * geo->all_luns;
+	pblk->max_write_pgs = min_t(int, max_write_ppas, NVM_MAX_VLBA);
+	pblk->max_write_pgs = min_t(int, pblk->max_write_pgs,
+		queue_max_hw_sectors(dev->q) / (geo->csecs >> SECTOR_SHIFT));
+	pblk_set_sec_per_write(pblk, pblk->min_write_pgs);
+
+	if (pblk->max_write_pgs > PBLK_MAX_REQ_ADDRS) {
+		pblk_err(pblk, "vector list too big(%u > %u)\n",
+				pblk->max_write_pgs, PBLK_MAX_REQ_ADDRS);
+		return -EINVAL;
+	}
+
+	pblk->pad_dist = kcalloc(pblk->min_write_pgs - 1, sizeof(atomic64_t),
+								GFP_KERNEL);
+	if (!pblk->pad_dist)
+		return -ENOMEM;
+
+	if (pblk_init_global_caches(pblk))
+		goto fail_free_pad_dist;
+
+	/* Internal bios can be at most the sectors signaled by the device. */
+	ret = mempool_init_page_pool(&pblk->page_bio_pool, NVM_MAX_VLBA, 0);
+	if (ret)
+		goto free_global_caches;
+
+	ret = mempool_init_slab_pool(&pblk->gen_ws_pool, PBLK_GEN_WS_POOL_SIZE,
+				     pblk_ws_cache);
+	if (ret)
+		goto free_page_bio_pool;
+
+	ret = mempool_init_slab_pool(&pblk->rec_pool, geo->all_luns,
+				     pblk_rec_cache);
+	if (ret)
+		goto free_gen_ws_pool;
+
+	ret = mempool_init_slab_pool(&pblk->r_rq_pool, geo->all_luns,
+				     pblk_g_rq_cache);
+	if (ret)
+		goto free_rec_pool;
+
+	ret = mempool_init_slab_pool(&pblk->e_rq_pool, geo->all_luns,
+				     pblk_g_rq_cache);
+	if (ret)
+		goto free_r_rq_pool;
+
+	ret = mempool_init_slab_pool(&pblk->w_rq_pool, geo->all_luns,
+				     pblk_w_rq_cache);
+	if (ret)
+		goto free_e_rq_pool;
+
+	pblk->close_wq = alloc_workqueue("pblk-close-wq",
+			WQ_MEM_RECLAIM | WQ_UNBOUND, PBLK_NR_CLOSE_JOBS);
+	if (!pblk->close_wq)
+		goto free_w_rq_pool;
+
+	pblk->bb_wq = alloc_workqueue("pblk-bb-wq",
+			WQ_MEM_RECLAIM | WQ_UNBOUND, 0);
+	if (!pblk->bb_wq)
+		goto free_close_wq;
+
+	pblk->r_end_wq = alloc_workqueue("pblk-read-end-wq",
+			WQ_MEM_RECLAIM | WQ_UNBOUND, 0);
+	if (!pblk->r_end_wq)
+		goto free_bb_wq;
+
+	if (pblk_set_addrf(pblk))
+		goto free_r_end_wq;
+
+	INIT_LIST_HEAD(&pblk->compl_list);
+	INIT_LIST_HEAD(&pblk->resubmit_list);
+
+	return 0;
+
+free_r_end_wq:
+	destroy_workqueue(pblk->r_end_wq);
+free_bb_wq:
+	destroy_workqueue(pblk->bb_wq);
+free_close_wq:
+	destroy_workqueue(pblk->close_wq);
+free_w_rq_pool:
+	mempool_exit(&pblk->w_rq_pool);
+free_e_rq_pool:
+	mempool_exit(&pblk->e_rq_pool);
+free_r_rq_pool:
+	mempool_exit(&pblk->r_rq_pool);
+free_rec_pool:
+	mempool_exit(&pblk->rec_pool);
+free_gen_ws_pool:
+	mempool_exit(&pblk->gen_ws_pool);
+free_page_bio_pool:
+	mempool_exit(&pblk->page_bio_pool);
+free_global_caches:
+	pblk_free_global_caches(pblk);
+fail_free_pad_dist:
+	kfree(pblk->pad_dist);
+	return -ENOMEM;
+}
+
+static void pblk_core_free(struct pblk *pblk)
+{
+	if (pblk->close_wq)
+		destroy_workqueue(pblk->close_wq);
+
+	if (pblk->r_end_wq)
+		destroy_workqueue(pblk->r_end_wq);
+
+	if (pblk->bb_wq)
+		destroy_workqueue(pblk->bb_wq);
+
+	mempool_exit(&pblk->page_bio_pool);
+	mempool_exit(&pblk->gen_ws_pool);
+	mempool_exit(&pblk->rec_pool);
+	mempool_exit(&pblk->r_rq_pool);
+	mempool_exit(&pblk->e_rq_pool);
+	mempool_exit(&pblk->w_rq_pool);
+
+	pblk_free_global_caches(pblk);
+	kfree(pblk->pad_dist);
+}
+
+static void pblk_line_mg_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);
+	kfree(l_mg->vsc_list);
+
+	for (i = 0; i < PBLK_DATA_LINES; i++) {
+		kfree(l_mg->sline_meta[i]);
+		pblk_mfree(l_mg->eline_meta[i]->buf, l_mg->emeta_alloc_type);
+		kfree(l_mg->eline_meta[i]);
+	}
+}
+
+static void pblk_line_meta_free(struct pblk_line_mgmt *l_mg,
+				struct pblk_line *line)
+{
+	struct pblk_w_err_gc *w_err_gc = line->w_err_gc;
+
+	kfree(line->blk_bitmap);
+	kfree(line->erase_bitmap);
+	kfree(line->chks);
+
+	pblk_mfree(w_err_gc->lba_list, l_mg->emeta_alloc_type);
+	kfree(w_err_gc);
+}
+
+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(line);
+		pblk_line_meta_free(l_mg, line);
+	}
+	spin_unlock(&l_mg->free_lock);
+
+	pblk_line_mg_free(pblk);
+
+	kfree(pblk->luns);
+	kfree(pblk->lines);
+}
+
+static int pblk_bb_get_tbl(struct nvm_tgt_dev *dev, struct pblk_lun *rlun,
+			   u8 *blks, int nr_blks)
+{
+	struct ppa_addr ppa;
+	int ret;
+
+	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)
+		return ret;
+
+	nr_blks = nvm_bb_tbl_fold(dev->parent, blks, nr_blks);
+	if (nr_blks < 0)
+		return -EIO;
+
+	return 0;
+}
+
+static void *pblk_bb_get_meta(struct pblk *pblk)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	u8 *meta;
+	int i, nr_blks, blk_per_lun;
+	int ret;
+
+	blk_per_lun = geo->num_chk * geo->pln_mode;
+	nr_blks = blk_per_lun * geo->all_luns;
+
+	meta = kmalloc(nr_blks, GFP_KERNEL);
+	if (!meta)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < geo->all_luns; i++) {
+		struct pblk_lun *rlun = &pblk->luns[i];
+		u8 *meta_pos = meta + i * blk_per_lun;
+
+		ret = pblk_bb_get_tbl(dev, rlun, meta_pos, blk_per_lun);
+		if (ret) {
+			kfree(meta);
+			return ERR_PTR(-EIO);
+		}
+	}
+
+	return meta;
+}
+
+static void *pblk_chunk_get_meta(struct pblk *pblk)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+
+	if (geo->version == NVM_OCSSD_SPEC_12)
+		return pblk_bb_get_meta(pblk);
+	else
+		return pblk_chunk_get_info(pblk);
+}
+
+static int pblk_luns_init(struct pblk *pblk)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_lun *rlun;
+	int i;
+
+	/* TODO: Implement unbalanced LUN support */
+	if (geo->num_lun < 0) {
+		pblk_err(pblk, "unbalanced LUN config.\n");
+		return -EINVAL;
+	}
+
+	pblk->luns = kcalloc(geo->all_luns, sizeof(struct pblk_lun),
+								GFP_KERNEL);
+	if (!pblk->luns)
+		return -ENOMEM;
+
+	for (i = 0; i < geo->all_luns; i++) {
+		/* Stripe across channels */
+		int ch = i % geo->num_ch;
+		int lun_raw = i / geo->num_ch;
+		int lunid = lun_raw + ch * geo->num_lun;
+
+		rlun = &pblk->luns[i];
+		rlun->bppa = dev->luns[lunid];
+
+		sema_init(&rlun->wr_sem, 1);
+	}
+
+	return 0;
+}
+
+/* See comment over struct line_emeta definition */
+static unsigned int calc_emeta_len(struct pblk *pblk)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+
+	/* Round to sector size so that lba_list starts on its own sector */
+	lm->emeta_sec[1] = DIV_ROUND_UP(
+			sizeof(struct line_emeta) + lm->blk_bitmap_len +
+			sizeof(struct wa_counters), geo->csecs);
+	lm->emeta_len[1] = lm->emeta_sec[1] * geo->csecs;
+
+	/* Round to sector size so that vsc_list starts on its own sector */
+	lm->dsec_per_line = lm->sec_per_line - lm->emeta_sec[0];
+	lm->emeta_sec[2] = DIV_ROUND_UP(lm->dsec_per_line * sizeof(u64),
+			geo->csecs);
+	lm->emeta_len[2] = lm->emeta_sec[2] * geo->csecs;
+
+	lm->emeta_sec[3] = DIV_ROUND_UP(l_mg->nr_lines * sizeof(u32),
+			geo->csecs);
+	lm->emeta_len[3] = lm->emeta_sec[3] * geo->csecs;
+
+	lm->vsc_list_len = l_mg->nr_lines * sizeof(u32);
+
+	return (lm->emeta_len[1] + lm->emeta_len[2] + lm->emeta_len[3]);
+}
+
+static void pblk_set_provision(struct pblk *pblk, long nr_free_blks)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct nvm_geo *geo = &dev->geo;
+	sector_t provisioned;
+	int sec_meta, blk_meta;
+
+	if (geo->op == NVM_TARGET_DEFAULT_OP)
+		pblk->op = PBLK_DEFAULT_OP;
+	else
+		pblk->op = geo->op;
+
+	provisioned = nr_free_blks;
+	provisioned *= (100 - pblk->op);
+	sector_div(provisioned, 100);
+
+	pblk->op_blks = nr_free_blks - provisioned;
+
+	/* Internally pblk manages all free blocks, but all calculations based
+	 * on user capacity consider only provisioned blocks
+	 */
+	pblk->rl.total_blocks = nr_free_blks;
+	pblk->rl.nr_secs = nr_free_blks * geo->clba;
+
+	/* Consider sectors used for metadata */
+	sec_meta = (lm->smeta_sec + lm->emeta_sec[0]) * l_mg->nr_free_lines;
+	blk_meta = DIV_ROUND_UP(sec_meta, geo->clba);
+
+	pblk->capacity = (provisioned - blk_meta) * geo->clba;
+
+	atomic_set(&pblk->rl.free_blocks, nr_free_blks);
+	atomic_set(&pblk->rl.free_user_blocks, nr_free_blks);
+}
+
+static int pblk_setup_line_meta_12(struct pblk *pblk, struct pblk_line *line,
+				   void *chunk_meta)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_line_meta *lm = &pblk->lm;
+	int i, chk_per_lun, nr_bad_chks = 0;
+
+	chk_per_lun = geo->num_chk * geo->pln_mode;
+
+	for (i = 0; i < lm->blk_per_line; i++) {
+		struct pblk_lun *rlun = &pblk->luns[i];
+		struct nvm_chk_meta *chunk;
+		int pos = pblk_ppa_to_pos(geo, rlun->bppa);
+		u8 *lun_bb_meta = chunk_meta + pos * chk_per_lun;
+
+		chunk = &line->chks[pos];
+
+		/*
+		 * In 1.2 spec. chunk state is not persisted by the device. Thus
+		 * some of the values are reset each time pblk is instantiated,
+		 * so we have to assume that the block is closed.
+		 */
+		if (lun_bb_meta[line->id] == NVM_BLK_T_FREE)
+			chunk->state =  NVM_CHK_ST_CLOSED;
+		else
+			chunk->state = NVM_CHK_ST_OFFLINE;
+
+		chunk->type = NVM_CHK_TP_W_SEQ;
+		chunk->wi = 0;
+		chunk->slba = -1;
+		chunk->cnlb = geo->clba;
+		chunk->wp = 0;
+
+		if (!(chunk->state & NVM_CHK_ST_OFFLINE))
+			continue;
+
+		set_bit(pos, line->blk_bitmap);
+		nr_bad_chks++;
+	}
+
+	return nr_bad_chks;
+}
+
+static int pblk_setup_line_meta_20(struct pblk *pblk, struct pblk_line *line,
+				   struct nvm_chk_meta *meta)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_line_meta *lm = &pblk->lm;
+	int i, nr_bad_chks = 0;
+
+	for (i = 0; i < lm->blk_per_line; i++) {
+		struct pblk_lun *rlun = &pblk->luns[i];
+		struct nvm_chk_meta *chunk;
+		struct nvm_chk_meta *chunk_meta;
+		struct ppa_addr ppa;
+		int pos;
+
+		ppa = rlun->bppa;
+		pos = pblk_ppa_to_pos(geo, ppa);
+		chunk = &line->chks[pos];
+
+		ppa.m.chk = line->id;
+		chunk_meta = pblk_chunk_get_off(pblk, meta, ppa);
+
+		chunk->state = chunk_meta->state;
+		chunk->type = chunk_meta->type;
+		chunk->wi = chunk_meta->wi;
+		chunk->slba = chunk_meta->slba;
+		chunk->cnlb = chunk_meta->cnlb;
+		chunk->wp = chunk_meta->wp;
+
+		if (chunk->type & NVM_CHK_TP_SZ_SPEC) {
+			WARN_ONCE(1, "pblk: custom-sized chunks unsupported\n");
+			continue;
+		}
+
+		if (!(chunk->state & NVM_CHK_ST_OFFLINE))
+			continue;
+
+		set_bit(pos, line->blk_bitmap);
+		nr_bad_chks++;
+	}
+
+	return nr_bad_chks;
+}
+
+static long pblk_setup_line_meta(struct pblk *pblk, struct pblk_line *line,
+				 void *chunk_meta, int line_id)
+{
+	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;
+	long nr_bad_chks, chk_in_line;
+
+	line->pblk = pblk;
+	line->id = line_id;
+	line->type = PBLK_LINETYPE_FREE;
+	line->state = PBLK_LINESTATE_NEW;
+	line->gc_group = PBLK_LINEGC_NONE;
+	line->vsc = &l_mg->vsc_list[line_id];
+	spin_lock_init(&line->lock);
+
+	if (geo->version == NVM_OCSSD_SPEC_12)
+		nr_bad_chks = pblk_setup_line_meta_12(pblk, line, chunk_meta);
+	else
+		nr_bad_chks = pblk_setup_line_meta_20(pblk, line, chunk_meta);
+
+	chk_in_line = lm->blk_per_line - nr_bad_chks;
+	if (nr_bad_chks < 0 || nr_bad_chks > lm->blk_per_line ||
+					chk_in_line < lm->min_blk_line) {
+		line->state = PBLK_LINESTATE_BAD;
+		list_add_tail(&line->list, &l_mg->bad_list);
+		return 0;
+	}
+
+	atomic_set(&line->blk_in_line, chk_in_line);
+	list_add_tail(&line->list, &l_mg->free_list);
+	l_mg->nr_free_lines++;
+
+	return chk_in_line;
+}
+
+static int pblk_alloc_line_meta(struct pblk *pblk, struct pblk_line *line)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+
+	line->blk_bitmap = kzalloc(lm->blk_bitmap_len, GFP_KERNEL);
+	if (!line->blk_bitmap)
+		return -ENOMEM;
+
+	line->erase_bitmap = kzalloc(lm->blk_bitmap_len, GFP_KERNEL);
+	if (!line->erase_bitmap)
+		goto free_blk_bitmap;
+
+
+	line->chks = kmalloc_array(lm->blk_per_line,
+				   sizeof(struct nvm_chk_meta), GFP_KERNEL);
+	if (!line->chks)
+		goto free_erase_bitmap;
+
+	line->w_err_gc = kzalloc(sizeof(struct pblk_w_err_gc), GFP_KERNEL);
+	if (!line->w_err_gc)
+		goto free_chks;
+
+	return 0;
+
+free_chks:
+	kfree(line->chks);
+free_erase_bitmap:
+	kfree(line->erase_bitmap);
+free_blk_bitmap:
+	kfree(line->blk_bitmap);
+	return -ENOMEM;
+}
+
+static int pblk_line_mg_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;
+	int i, bb_distance;
+
+	l_mg->nr_lines = geo->num_chk;
+	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);
+
+	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);
+	INIT_LIST_HEAD(&l_mg->gc_werr_list);
+
+	INIT_LIST_HEAD(&l_mg->emeta_list);
+
+	l_mg->gc_lists[0] = &l_mg->gc_werr_list;
+	l_mg->gc_lists[1] = &l_mg->gc_high_list;
+	l_mg->gc_lists[2] = &l_mg->gc_mid_list;
+	l_mg->gc_lists[3] = &l_mg->gc_low_list;
+
+	spin_lock_init(&l_mg->free_lock);
+	spin_lock_init(&l_mg->close_lock);
+	spin_lock_init(&l_mg->gc_lock);
+
+	l_mg->vsc_list = kcalloc(l_mg->nr_lines, sizeof(__le32), GFP_KERNEL);
+	if (!l_mg->vsc_list)
+		goto fail;
+
+	l_mg->bb_template = kzalloc(lm->sec_bitmap_len, GFP_KERNEL);
+	if (!l_mg->bb_template)
+		goto fail_free_vsc_list;
+
+	l_mg->bb_aux = kzalloc(lm->sec_bitmap_len, GFP_KERNEL);
+	if (!l_mg->bb_aux)
+		goto fail_free_bb_template;
+
+	/* smeta is always small enough to fit on a kmalloc memory allocation,
+	 * emeta depends on the number of LUNs allocated to the pblk instance
+	 */
+	for (i = 0; i < PBLK_DATA_LINES; i++) {
+		l_mg->sline_meta[i] = kmalloc(lm->smeta_len, GFP_KERNEL);
+		if (!l_mg->sline_meta[i])
+			goto fail_free_smeta;
+	}
+
+	/* emeta allocates three different buffers for managing metadata with
+	 * in-memory and in-media layouts
+	 */
+	for (i = 0; i < PBLK_DATA_LINES; i++) {
+		struct pblk_emeta *emeta;
+
+		emeta = kmalloc(sizeof(struct pblk_emeta), GFP_KERNEL);
+		if (!emeta)
+			goto fail_free_emeta;
+
+		if (lm->emeta_len[0] > KMALLOC_MAX_CACHE_SIZE) {
+			l_mg->emeta_alloc_type = PBLK_VMALLOC_META;
+
+			emeta->buf = vmalloc(lm->emeta_len[0]);
+			if (!emeta->buf) {
+				kfree(emeta);
+				goto fail_free_emeta;
+			}
+
+			emeta->nr_entries = lm->emeta_sec[0];
+			l_mg->eline_meta[i] = emeta;
+		} else {
+			l_mg->emeta_alloc_type = PBLK_KMALLOC_META;
+
+			emeta->buf = kmalloc(lm->emeta_len[0], GFP_KERNEL);
+			if (!emeta->buf) {
+				kfree(emeta);
+				goto fail_free_emeta;
+			}
+
+			emeta->nr_entries = lm->emeta_sec[0];
+			l_mg->eline_meta[i] = emeta;
+		}
+	}
+
+	for (i = 0; i < l_mg->nr_lines; i++)
+		l_mg->vsc_list[i] = cpu_to_le32(EMPTY_ENTRY);
+
+	bb_distance = (geo->all_luns) * geo->ws_opt;
+	for (i = 0; i < lm->sec_per_line; i += bb_distance)
+		bitmap_set(l_mg->bb_template, i, geo->ws_opt);
+
+	return 0;
+
+fail_free_emeta:
+	while (--i >= 0) {
+		if (l_mg->emeta_alloc_type == PBLK_VMALLOC_META)
+			vfree(l_mg->eline_meta[i]->buf);
+		else
+			kfree(l_mg->eline_meta[i]->buf);
+		kfree(l_mg->eline_meta[i]);
+	}
+fail_free_smeta:
+	for (i = 0; i < PBLK_DATA_LINES; i++)
+		kfree(l_mg->sline_meta[i]);
+	kfree(l_mg->bb_aux);
+fail_free_bb_template:
+	kfree(l_mg->bb_template);
+fail_free_vsc_list:
+	kfree(l_mg->vsc_list);
+fail:
+	return -ENOMEM;
+}
+
+static int pblk_line_meta_init(struct pblk *pblk)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_line_meta *lm = &pblk->lm;
+	unsigned int smeta_len, emeta_len;
+	int i;
+
+	lm->sec_per_line = geo->clba * geo->all_luns;
+	lm->blk_per_line = geo->all_luns;
+	lm->blk_bitmap_len = BITS_TO_LONGS(geo->all_luns) * sizeof(long);
+	lm->sec_bitmap_len = BITS_TO_LONGS(lm->sec_per_line) * sizeof(long);
+	lm->lun_bitmap_len = BITS_TO_LONGS(geo->all_luns) * sizeof(long);
+	lm->mid_thrs = lm->sec_per_line / 2;
+	lm->high_thrs = lm->sec_per_line / 4;
+	lm->meta_distance = (geo->all_luns / 2) * pblk->min_write_pgs;
+
+	/* Calculate necessary pages for smeta. See comment over struct
+	 * line_smeta definition
+	 */
+	i = 1;
+add_smeta_page:
+	lm->smeta_sec = i * geo->ws_opt;
+	lm->smeta_len = lm->smeta_sec * geo->csecs;
+
+	smeta_len = sizeof(struct line_smeta) + 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[0] = i * geo->ws_opt;
+	lm->emeta_len[0] = lm->emeta_sec[0] * geo->csecs;
+
+	emeta_len = calc_emeta_len(pblk);
+	if (emeta_len > lm->emeta_len[0]) {
+		i++;
+		goto add_emeta_page;
+	}
+
+	lm->emeta_bb = geo->all_luns > i ? geo->all_luns - i : 0;
+
+	lm->min_blk_line = 1;
+	if (geo->all_luns > 1)
+		lm->min_blk_line += DIV_ROUND_UP(lm->smeta_sec +
+					lm->emeta_sec[0], geo->clba);
+
+	if (lm->min_blk_line > lm->blk_per_line) {
+		pblk_err(pblk, "config. not supported. Min. LUN in line:%d\n",
+							lm->blk_per_line);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int pblk_lines_init(struct pblk *pblk)
+{
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line *line;
+	void *chunk_meta;
+	long nr_free_chks = 0;
+	int i, ret;
+
+	ret = pblk_line_meta_init(pblk);
+	if (ret)
+		return ret;
+
+	ret = pblk_line_mg_init(pblk);
+	if (ret)
+		return ret;
+
+	ret = pblk_luns_init(pblk);
+	if (ret)
+		goto fail_free_meta;
+
+	chunk_meta = pblk_chunk_get_meta(pblk);
+	if (IS_ERR(chunk_meta)) {
+		ret = PTR_ERR(chunk_meta);
+		goto fail_free_luns;
+	}
+
+	pblk->lines = kcalloc(l_mg->nr_lines, sizeof(struct pblk_line),
+								GFP_KERNEL);
+	if (!pblk->lines) {
+		ret = -ENOMEM;
+		goto fail_free_chunk_meta;
+	}
+
+	for (i = 0; i < l_mg->nr_lines; i++) {
+		line = &pblk->lines[i];
+
+		ret = pblk_alloc_line_meta(pblk, line);
+		if (ret)
+			goto fail_free_lines;
+
+		nr_free_chks += pblk_setup_line_meta(pblk, line, chunk_meta, i);
+	}
+
+	if (!nr_free_chks) {
+		pblk_err(pblk, "too many bad blocks prevent for sane instance\n");
+		ret = -EINTR;
+		goto fail_free_lines;
+	}
+
+	pblk_set_provision(pblk, nr_free_chks);
+
+	kfree(chunk_meta);
+	return 0;
+
+fail_free_lines:
+	while (--i >= 0)
+		pblk_line_meta_free(l_mg, &pblk->lines[i]);
+	kfree(pblk->lines);
+fail_free_chunk_meta:
+	kfree(chunk_meta);
+fail_free_luns:
+	kfree(pblk->luns);
+fail_free_meta:
+	pblk_line_mg_free(pblk);
+
+	return ret;
+}
+
+static int pblk_writer_init(struct pblk *pblk)
+{
+	pblk->writer_ts = kthread_create(pblk_write_ts, pblk, "pblk-writer-t");
+	if (IS_ERR(pblk->writer_ts)) {
+		int err = PTR_ERR(pblk->writer_ts);
+
+		if (err != -EINTR)
+			pblk_err(pblk, "could not allocate writer kthread (%d)\n",
+					err);
+		return err;
+	}
+
+	timer_setup(&pblk->wtimer, pblk_write_timer_fn, 0);
+	mod_timer(&pblk->wtimer, jiffies + msecs_to_jiffies(100));
+
+	return 0;
+}
+
+static void pblk_writer_stop(struct pblk *pblk)
+{
+	/* The pipeline must be stopped and the write buffer emptied before the
+	 * write thread is stopped
+	 */
+	WARN(pblk_rb_read_count(&pblk->rwb),
+			"Stopping not fully persisted write buffer\n");
+
+	WARN(pblk_rb_sync_count(&pblk->rwb),
+			"Stopping not fully synced write buffer\n");
+
+	del_timer_sync(&pblk->wtimer);
+	if (pblk->writer_ts)
+		kthread_stop(pblk->writer_ts);
+}
+
+static void pblk_free(struct pblk *pblk)
+{
+	pblk_lines_free(pblk);
+	pblk_l2p_free(pblk);
+	pblk_rwb_free(pblk);
+	pblk_core_free(pblk);
+
+	kfree(pblk);
+}
+
+static void pblk_tear_down(struct pblk *pblk, bool graceful)
+{
+	if (graceful)
+		__pblk_pipeline_flush(pblk);
+	__pblk_pipeline_stop(pblk);
+	pblk_writer_stop(pblk);
+	pblk_rb_sync_l2p(&pblk->rwb);
+	pblk_rl_free(&pblk->rl);
+
+	pblk_debug(pblk, "consistent tear down (graceful:%d)\n", graceful);
+}
+
+static void pblk_exit(void *private, bool graceful)
+{
+	struct pblk *pblk = private;
+
+	down_write(&pblk_lock);
+	pblk_gc_exit(pblk, graceful);
+	pblk_tear_down(pblk, graceful);
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	pblk_info(pblk, "exit: L2P CRC: %x\n", pblk_l2p_crc(pblk));
+#endif
+
+	pblk_free(pblk);
+	up_write(&pblk_lock);
+}
+
+static sector_t pblk_capacity(void *private)
+{
+	struct pblk *pblk = private;
+
+	return pblk->capacity * NR_PHY_IN_LOG;
+}
+
+static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
+		       int flags)
+{
+	struct nvm_geo *geo = &dev->geo;
+	struct request_queue *bqueue = dev->q;
+	struct request_queue *tqueue = tdisk->queue;
+	struct pblk *pblk;
+	int ret;
+
+	pblk = kzalloc(sizeof(struct pblk), GFP_KERNEL);
+	if (!pblk)
+		return ERR_PTR(-ENOMEM);
+
+	pblk->dev = dev;
+	pblk->disk = tdisk;
+	pblk->state = PBLK_STATE_RUNNING;
+	pblk->gc.gc_enabled = 0;
+
+	if (!(geo->version == NVM_OCSSD_SPEC_12 ||
+					geo->version == NVM_OCSSD_SPEC_20)) {
+		pblk_err(pblk, "OCSSD version not supported (%u)\n",
+							geo->version);
+		kfree(pblk);
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (geo->version == NVM_OCSSD_SPEC_12 && geo->dom & NVM_RSP_L2P) {
+		pblk_err(pblk, "host-side L2P table not supported. (%x)\n",
+							geo->dom);
+		kfree(pblk);
+		return ERR_PTR(-EINVAL);
+	}
+
+	spin_lock_init(&pblk->resubmit_lock);
+	spin_lock_init(&pblk->trans_lock);
+	spin_lock_init(&pblk->lock);
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	atomic_long_set(&pblk->inflight_writes, 0);
+	atomic_long_set(&pblk->padded_writes, 0);
+	atomic_long_set(&pblk->padded_wb, 0);
+	atomic_long_set(&pblk->req_writes, 0);
+	atomic_long_set(&pblk->sub_writes, 0);
+	atomic_long_set(&pblk->sync_writes, 0);
+	atomic_long_set(&pblk->inflight_reads, 0);
+	atomic_long_set(&pblk->cache_reads, 0);
+	atomic_long_set(&pblk->sync_reads, 0);
+	atomic_long_set(&pblk->recov_writes, 0);
+	atomic_long_set(&pblk->recov_writes, 0);
+	atomic_long_set(&pblk->recov_gc_writes, 0);
+	atomic_long_set(&pblk->recov_gc_reads, 0);
+#endif
+
+	atomic_long_set(&pblk->read_failed, 0);
+	atomic_long_set(&pblk->read_empty, 0);
+	atomic_long_set(&pblk->read_high_ecc, 0);
+	atomic_long_set(&pblk->read_failed_gc, 0);
+	atomic_long_set(&pblk->write_failed, 0);
+	atomic_long_set(&pblk->erase_failed, 0);
+
+	ret = pblk_core_init(pblk);
+	if (ret) {
+		pblk_err(pblk, "could not initialize core\n");
+		goto fail;
+	}
+
+	ret = pblk_lines_init(pblk);
+	if (ret) {
+		pblk_err(pblk, "could not initialize lines\n");
+		goto fail_free_core;
+	}
+
+	ret = pblk_rwb_init(pblk);
+	if (ret) {
+		pblk_err(pblk, "could not initialize write buffer\n");
+		goto fail_free_lines;
+	}
+
+	ret = pblk_l2p_init(pblk, flags & NVM_TARGET_FACTORY);
+	if (ret) {
+		pblk_err(pblk, "could not initialize maps\n");
+		goto fail_free_rwb;
+	}
+
+	ret = pblk_writer_init(pblk);
+	if (ret) {
+		if (ret != -EINTR)
+			pblk_err(pblk, "could not initialize write thread\n");
+		goto fail_free_l2p;
+	}
+
+	ret = pblk_gc_init(pblk);
+	if (ret) {
+		pblk_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->clba * geo->csecs;
+	tqueue->limits.discard_alignment = 0;
+	blk_queue_max_discard_sectors(tqueue, UINT_MAX >> 9);
+	blk_queue_flag_set(QUEUE_FLAG_DISCARD, tqueue);
+
+	pblk_info(pblk, "luns:%u, lines:%d, secs:%llu, buf entries:%u\n",
+			geo->all_luns, pblk->l_mg.nr_lines,
+			(unsigned long long)pblk->rl.nr_secs,
+			pblk->rwb.nr_entries);
+
+	wake_up_process(pblk->writer_ts);
+
+	/* Check if we need to start GC */
+	pblk_gc_should_kick(pblk);
+
+	return pblk;
+
+fail_stop_writer:
+	pblk_writer_stop(pblk);
+fail_free_l2p:
+	pblk_l2p_free(pblk);
+fail_free_rwb:
+	pblk_rwb_free(pblk);
+fail_free_lines:
+	pblk_lines_free(pblk);
+fail_free_core:
+	pblk_core_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,
+	.owner		= THIS_MODULE,
+};
+
+static int __init pblk_module_init(void)
+{
+	int ret;
+
+	ret = bioset_init(&pblk_bio_set, BIO_POOL_SIZE, 0, 0);
+	if (ret)
+		return ret;
+	ret = nvm_register_tgt_type(&tt_pblk);
+	if (ret)
+		bioset_exit(&pblk_bio_set);
+	return ret;
+}
+
+static void pblk_module_exit(void)
+{
+	bioset_exit(&pblk_bio_set);
+	nvm_unregister_tgt_type(&tt_pblk);
+}
+
+module_init(pblk_module_init);
+module_exit(pblk_module_exit);
+MODULE_AUTHOR("Javier Gonzalez <javier@cnexlabs.com>");
+MODULE_AUTHOR("Matias Bjorling <matias@cnexlabs.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Physical Block-Device for Open-Channel SSDs");
diff --git a/src/kernel/linux/v4.19/drivers/lightnvm/pblk-map.c b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-map.c
new file mode 100644
index 0000000..953ca31
--- /dev/null
+++ b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-map.c
@@ -0,0 +1,188 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@cnexlabs.com>
+ *                  Matias Bjorling <matias@cnexlabs.com>
+ *
+ * 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 int 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 pblk_emeta *emeta;
+	struct pblk_w_ctx *w_ctx;
+	__le64 *lba_list;
+	u64 paddr;
+	int nr_secs = pblk->min_write_pgs;
+	int i;
+
+	if (pblk_line_is_full(line)) {
+		struct pblk_line *prev_line = line;
+
+		/* If we cannot allocate a new line, make sure to store metadata
+		 * on current line and then fail
+		 */
+		line = pblk_line_replace_data(pblk);
+		pblk_line_close_meta(pblk, prev_line);
+
+		if (!line)
+			return -EINTR;
+	}
+
+	emeta = line->emeta;
+	lba_list = emeta_to_lbas(pblk, emeta->buf);
+
+	paddr = pblk_alloc_page(pblk, line, nr_secs);
+
+	for (i = 0; i < nr_secs; i++, paddr++) {
+		__le64 addr_empty = cpu_to_le64(ADDR_EMPTY);
+
+		/* ppa to be sent to the device */
+		ppa_list[i] = addr_to_gen_ppa(pblk, paddr, line->id);
+
+		/* 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) {
+			kref_get(&line->ref);
+			w_ctx = pblk_rb_w_ctx(&pblk->rwb, sentry + i);
+			w_ctx->ppa = ppa_list[i];
+			meta_list[i].lba = cpu_to_le64(w_ctx->lba);
+			lba_list[paddr] = cpu_to_le64(w_ctx->lba);
+			if (lba_list[paddr] != addr_empty)
+				line->nr_valid_lbas++;
+			else
+				atomic64_inc(&pblk->pad_wa);
+		} else {
+			lba_list[paddr] = meta_list[i].lba = addr_empty;
+			__pblk_map_invalidate(pblk, line, paddr);
+		}
+	}
+
+	pblk_down_rq(pblk, ppa_list, nr_secs, lun_bitmap);
+	return 0;
+}
+
+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;
+		if (pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
+					lun_bitmap, &meta_list[i], map_secs)) {
+			bio_put(rqd->bio);
+			pblk_free_rqd(pblk, rqd, PBLK_WRITE);
+			pblk_pipeline_stop(pblk);
+		}
+	}
+}
+
+/* only if erase_ppa is set, acquire erase semaphore */
+void 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_meta *lm = &pblk->lm;
+	struct pblk_sec_meta *meta_list = rqd->meta_list;
+	struct pblk_line *e_line, *d_line;
+	unsigned int map_secs;
+	int min = pblk->min_write_pgs;
+	int i, erase_lun;
+
+	for (i = 0; i < rqd->nr_ppas; i += min) {
+		map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
+		if (pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
+					lun_bitmap, &meta_list[i], map_secs)) {
+			bio_put(rqd->bio);
+			pblk_free_rqd(pblk, rqd, PBLK_WRITE);
+			pblk_pipeline_stop(pblk);
+		}
+
+		erase_lun = pblk_ppa_to_pos(geo, rqd->ppa_list[i]);
+
+		/* line can change after page map. We might also be writing the
+		 * last line.
+		 */
+		e_line = pblk_line_get_erase(pblk);
+		if (!e_line)
+			return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
+							valid_secs, i + min);
+
+		spin_lock(&e_line->lock);
+		if (!test_bit(erase_lun, e_line->erase_bitmap)) {
+			set_bit(erase_lun, e_line->erase_bitmap);
+			atomic_dec(&e_line->left_eblks);
+
+			*erase_ppa = rqd->ppa_list[i];
+			erase_ppa->a.blk = e_line->id;
+
+			spin_unlock(&e_line->lock);
+
+			/* Avoid evaluating e_line->left_eblks */
+			return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
+							valid_secs, i + min);
+		}
+		spin_unlock(&e_line->lock);
+	}
+
+	d_line = pblk_line_get_data(pblk);
+
+	/* line can change after page map. We might also be writing the
+	 * last line.
+	 */
+	e_line = pblk_line_get_erase(pblk);
+	if (!e_line)
+		return;
+
+	/* Erase blocks that are bad in this line but might not be in next */
+	if (unlikely(pblk_ppa_empty(*erase_ppa)) &&
+			bitmap_weight(d_line->blk_bitmap, lm->blk_per_line)) {
+		int bit = -1;
+
+retry:
+		bit = find_next_bit(d_line->blk_bitmap,
+						lm->blk_per_line, bit + 1);
+		if (bit >= lm->blk_per_line)
+			return;
+
+		spin_lock(&e_line->lock);
+		if (test_bit(bit, e_line->erase_bitmap)) {
+			spin_unlock(&e_line->lock);
+			goto retry;
+		}
+		spin_unlock(&e_line->lock);
+
+		set_bit(bit, e_line->erase_bitmap);
+		atomic_dec(&e_line->left_eblks);
+		*erase_ppa = pblk->luns[bit].bppa; /* set ch and lun */
+		erase_ppa->a.blk = e_line->id;
+	}
+}
diff --git a/src/kernel/linux/v4.19/drivers/lightnvm/pblk-rb.c b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-rb.c
new file mode 100644
index 0000000..f6eec02
--- /dev/null
+++ b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-rb.c
@@ -0,0 +1,852 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@cnexlabs.com>
+ *
+ * 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.
+ *
+ * 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/core-api/circular-buffers.rst)
+ */
+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->flush_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_addr(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_addr(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_PBLK_DEBUG
+	atomic_set(&rb->inflight_flush_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);
+
+	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;
+
+	flags = READ_ONCE(w_ctx->flags);
+	WARN_ONCE(!(flags & PBLK_SUBMITTED_ENTRY),
+			"pblk: overwriting unsubmitted data\n");
+
+	/* Release flags on context. Protect from writes and reads */
+	smp_store_release(&w_ctx->flags, PBLK_WRITABLE_ENTRY);
+	pblk_ppa_set_empty(&w_ctx->ppa);
+	w_ctx->lba = ADDR_EMPTY;
+}
+
+#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.
+ */
+static 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_sync_count(struct pblk_rb *rb)
+{
+	unsigned int mem = READ_ONCE(rb->mem);
+	unsigned int sync = READ_ONCE(rb->sync);
+
+	return pblk_rb_ring_count(mem, sync, 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 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 user_io = 0, gc_io = 0;
+	unsigned int i;
+	int flags;
+
+	for (i = 0; i < to_update; i++) {
+		entry = &rb->entries[rb->l2p_update];
+		w_ctx = &entry->w_ctx;
+
+		flags = READ_ONCE(entry->w_ctx.flags);
+		if (flags & PBLK_IOTYPE_USER)
+			user_io++;
+		else if (flags & PBLK_IOTYPE_GC)
+			gc_io++;
+		else
+			WARN(1, "pblk: unknown IO type\n");
+
+		pblk_update_map_dev(pblk, w_ctx->lba, w_ctx->ppa,
+							entry->cacheline);
+
+		line = &pblk->lines[pblk_ppa_to_line(w_ctx->ppa)];
+		kref_put(&line->ref, pblk_line_put);
+		clean_wctx(w_ctx);
+		rb->l2p_update = (rb->l2p_update + 1) & (rb->nr_entries - 1);
+	}
+
+	pblk_rl_out(&pblk->rl, user_io, gc_io);
+
+	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;
+
+	lockdep_assert_held(&rb->w_lock);
+
+	/* 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, 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, 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.
+ *
+ */
+static void __pblk_rb_write_entry(struct pblk_rb *rb, void *data,
+				  struct pblk_w_ctx w_ctx,
+				  struct pblk_rb_entry *entry)
+{
+	memcpy(entry->data, data, rb->seg_size);
+
+	entry->w_ctx.lba = w_ctx.lba;
+	entry->w_ctx.ppa = w_ctx.ppa;
+}
+
+void pblk_rb_write_entry_user(struct pblk_rb *rb, void *data,
+			      struct pblk_w_ctx w_ctx, unsigned int ring_pos)
+{
+	struct pblk *pblk = container_of(rb, struct pblk, rwb);
+	struct pblk_rb_entry *entry;
+	int flags;
+
+	entry = &rb->entries[ring_pos];
+	flags = READ_ONCE(entry->w_ctx.flags);
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	/* Caller must guarantee that the entry is free */
+	BUG_ON(!(flags & PBLK_WRITABLE_ENTRY));
+#endif
+
+	__pblk_rb_write_entry(rb, data, w_ctx, entry);
+
+	pblk_update_map_cache(pblk, w_ctx.lba, entry->cacheline);
+	flags = w_ctx.flags | PBLK_WRITTEN_DATA;
+
+	/* Release flags on write context. Protect from writes */
+	smp_store_release(&entry->w_ctx.flags, flags);
+}
+
+void pblk_rb_write_entry_gc(struct pblk_rb *rb, void *data,
+			    struct pblk_w_ctx w_ctx, struct pblk_line *line,
+			    u64 paddr, unsigned int ring_pos)
+{
+	struct pblk *pblk = container_of(rb, struct pblk, rwb);
+	struct pblk_rb_entry *entry;
+	int flags;
+
+	entry = &rb->entries[ring_pos];
+	flags = READ_ONCE(entry->w_ctx.flags);
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	/* Caller must guarantee that the entry is free */
+	BUG_ON(!(flags & PBLK_WRITABLE_ENTRY));
+#endif
+
+	__pblk_rb_write_entry(rb, data, w_ctx, entry);
+
+	if (!pblk_update_map_gc(pblk, w_ctx.lba, entry->cacheline, line, paddr))
+		entry->w_ctx.lba = ADDR_EMPTY;
+
+	flags = w_ctx.flags | PBLK_WRITTEN_DATA;
+
+	/* Release flags on write context. Protect from writes */
+	smp_store_release(&entry->w_ctx.flags, flags);
+}
+
+static int pblk_rb_flush_point_set(struct pblk_rb *rb, struct bio *bio,
+				   unsigned int pos)
+{
+	struct pblk_rb_entry *entry;
+	unsigned int sync, flush_point;
+
+	pblk_rb_sync_init(rb, NULL);
+	sync = READ_ONCE(rb->sync);
+
+	if (pos == sync) {
+		pblk_rb_sync_end(rb, NULL);
+		return 0;
+	}
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	atomic_inc(&rb->inflight_flush_point);
+#endif
+
+	flush_point = (pos == 0) ? (rb->nr_entries - 1) : (pos - 1);
+	entry = &rb->entries[flush_point];
+
+	/* Protect flush points */
+	smp_store_release(&rb->flush_point, flush_point);
+
+	if (bio)
+		bio_list_add(&entry->w_ctx.bios, bio);
+
+	pblk_rb_sync_end(rb, NULL);
+
+	return bio ? 1 : 0;
+}
+
+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;
+}
+
+void pblk_rb_flush(struct pblk_rb *rb)
+{
+	struct pblk *pblk = container_of(rb, struct pblk, rwb);
+	unsigned int mem = READ_ONCE(rb->mem);
+
+	if (pblk_rb_flush_point_set(rb, NULL, mem))
+		return;
+
+	pblk_write_kick(pblk);
+}
+
+static int pblk_rb_may_write_flush(struct pblk_rb *rb, unsigned int nr_entries,
+				   unsigned int *pos, struct bio *bio,
+				   int *io_ret)
+{
+	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);
+
+		atomic64_inc(&pblk->nr_flush);
+		if (pblk_rb_flush_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 io_ret;
+
+	spin_lock(&rb->w_lock);
+	io_ret = pblk_rl_user_may_insert(&pblk->rl, nr_entries);
+	if (io_ret) {
+		spin_unlock(&rb->w_lock);
+		return io_ret;
+	}
+
+	if (!pblk_rb_may_write_flush(rb, nr_entries, pos, bio, &io_ret)) {
+		spin_unlock(&rb->w_lock);
+		return NVM_IO_REQUEUE;
+	}
+
+	pblk_rl_user_in(&pblk->rl, nr_entries);
+	spin_unlock(&rb->w_lock);
+
+	return io_ret;
+}
+
+/*
+ * 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;
+}
+
+/*
+ * 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 nvm_rq *rqd,
+				 unsigned int pos, unsigned int nr_entries,
+				 unsigned int count)
+{
+	struct pblk *pblk = container_of(rb, struct pblk, rwb);
+	struct request_queue *q = pblk->dev->q;
+	struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
+	struct bio *bio = rqd->bio;
+	struct pblk_rb_entry *entry;
+	struct page *page;
+	unsigned int pad = 0, to_read = nr_entries;
+	unsigned int i;
+	int flags;
+
+	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)) {
+			io_schedule();
+			goto try;
+		}
+
+		page = virt_to_page(entry->data);
+		if (!page) {
+			pblk_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);
+			return NVM_IO_ERR;
+		}
+
+		if (bio_add_pc_page(q, bio, page, rb->seg_size, 0) !=
+								rb->seg_size) {
+			pblk_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);
+			return NVM_IO_ERR;
+		}
+
+		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);
+	}
+
+	if (pad) {
+		if (pblk_bio_add_pages(pblk, bio, GFP_KERNEL, pad)) {
+			pblk_err(pblk, "could not pad page in write bio\n");
+			return NVM_IO_ERR;
+		}
+
+		if (pad < pblk->min_write_pgs)
+			atomic64_inc(&pblk->pad_dist[pad - 1]);
+		else
+			pblk_warn(pblk, "padding more than min. sectors\n");
+
+		atomic64_add(pad, &pblk->pad_wa);
+	}
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	atomic_long_add(pad, &pblk->padded_writes);
+#endif
+
+	return NVM_IO_OK;
+}
+
+/*
+ * 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,
+			struct ppa_addr ppa, int bio_iter, bool advanced_bio)
+{
+	struct pblk *pblk = container_of(rb, struct pblk, rwb);
+	struct pblk_rb_entry *entry;
+	struct pblk_w_ctx *w_ctx;
+	struct ppa_addr l2p_ppa;
+	u64 pos = pblk_addr_to_cacheline(ppa);
+	void *data;
+	int flags;
+	int ret = 1;
+
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	/* Caller must ensure that the access will not cause an overflow */
+	BUG_ON(pos >= rb->nr_entries);
+#endif
+	entry = &rb->entries[pos];
+	w_ctx = &entry->w_ctx;
+	flags = READ_ONCE(w_ctx->flags);
+
+	spin_lock(&rb->w_lock);
+	spin_lock(&pblk->trans_lock);
+	l2p_ppa = pblk_trans_map_get(pblk, lba);
+	spin_unlock(&pblk->trans_lock);
+
+	/* Check if the entry has been overwritten or is scheduled to be */
+	if (!pblk_ppa_comp(l2p_ppa, ppa) || 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(!advanced_bio))
+		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)
+	__acquires(&rb->s_lock)
+{
+	if (flags)
+		spin_lock_irqsave(&rb->s_lock, *flags);
+	else
+		spin_lock_irq(&rb->s_lock);
+
+	return rb->sync;
+}
+
+void pblk_rb_sync_end(struct pblk_rb *rb, unsigned long *flags)
+	__releases(&rb->s_lock)
+{
+	lockdep_assert_held(&rb->s_lock);
+
+	if (flags)
+		spin_unlock_irqrestore(&rb->s_lock, *flags);
+	else
+		spin_unlock_irq(&rb->s_lock);
+}
+
+unsigned int pblk_rb_sync_advance(struct pblk_rb *rb, unsigned int nr_entries)
+{
+	unsigned int sync, flush_point;
+	lockdep_assert_held(&rb->s_lock);
+
+	sync = READ_ONCE(rb->sync);
+	flush_point = READ_ONCE(rb->flush_point);
+
+	if (flush_point != EMPTY_ENTRY) {
+		unsigned int secs_to_flush;
+
+		secs_to_flush = pblk_rb_ring_count(flush_point, sync,
+					rb->nr_entries);
+		if (secs_to_flush < nr_entries) {
+			/* Protect flush points */
+			smp_store_release(&rb->flush_point, EMPTY_ENTRY);
+		}
+	}
+
+	sync = (sync + nr_entries) & (rb->nr_entries - 1);
+
+	/* Protect from counts */
+	smp_store_release(&rb->sync, sync);
+
+	return sync;
+}
+
+/* Calculate how many sectors to submit up to the current flush point. */
+unsigned int pblk_rb_flush_point_count(struct pblk_rb *rb)
+{
+	unsigned int subm, sync, flush_point;
+	unsigned int submitted, to_flush;
+
+	/* Protect flush points */
+	flush_point = smp_load_acquire(&rb->flush_point);
+	if (flush_point == EMPTY_ENTRY)
+		return 0;
+
+	/* Protect syncs */
+	sync = smp_load_acquire(&rb->sync);
+
+	subm = READ_ONCE(rb->subm);
+	submitted = pblk_rb_ring_count(subm, sync, rb->nr_entries);
+
+	/* The sync point itself counts as a sector to sync */
+	to_flush = pblk_rb_ring_count(flush_point, sync, rb->nr_entries) + 1;
+
+	return (submitted < to_flush) ? (to_flush - submitted) : 0;
+}
+
+/*
+ * 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)
+{
+	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++)
+		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->flush_point == EMPTY_ENTRY)) {
+		goto out;
+	}
+
+	if (!rb->entries) {
+		ret = 1;
+		goto out;
+	}
+
+	for (i = 0; i < rb->nr_entries; i++) {
+		entry = &rb->entries[i];
+
+		if (!entry->data) {
+			ret = 1;
+			goto out;
+		}
+	}
+
+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->flush_point != EMPTY_ENTRY)
+		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_PBLK_DEBUG
+			atomic_read(&rb->inflight_flush_point),
+#else
+			0,
+#endif
+			rb->flush_point,
+			pblk_rb_read_count(rb),
+			pblk_rb_space(rb),
+			pblk_rb_flush_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_PBLK_DEBUG
+			atomic_read(&rb->inflight_flush_point),
+#else
+			0,
+#endif
+			pblk_rb_read_count(rb),
+			pblk_rb_space(rb),
+			pblk_rb_flush_point_count(rb),
+			queued_entries);
+
+	return offset;
+}
diff --git a/src/kernel/linux/v4.19/drivers/lightnvm/pblk-read.c b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-read.c
new file mode 100644
index 0000000..5a46d7f
--- /dev/null
+++ b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-read.c
@@ -0,0 +1,701 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@cnexlabs.com>
+ *                  Matias Bjorling <matias@cnexlabs.com>
+ *
+ * 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, bool advanced_bio)
+{
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	/* Callers must ensure that the ppa points to a cache address */
+	BUG_ON(pblk_ppa_empty(ppa));
+	BUG_ON(!pblk_addr_in_cache(ppa));
+#endif
+
+	return pblk_rb_copy_to_bio(&pblk->rwb, bio, lba, ppa,
+						bio_iter, advanced_bio);
+}
+
+static void pblk_read_ppalist_rq(struct pblk *pblk, struct nvm_rq *rqd,
+				 struct bio *bio, sector_t blba,
+				 unsigned long *read_bitmap)
+{
+	struct pblk_sec_meta *meta_list = rqd->meta_list;
+	struct ppa_addr ppas[PBLK_MAX_REQ_ADDRS];
+	int nr_secs = rqd->nr_ppas;
+	bool advanced_bio = false;
+	int i, j = 0;
+
+	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 (pblk_ppa_empty(p)) {
+			WARN_ON(test_and_set_bit(i, read_bitmap));
+			meta_list[i].lba = cpu_to_le64(ADDR_EMPTY);
+
+			if (unlikely(!advanced_bio)) {
+				bio_advance(bio, (i) * PBLK_EXPOSED_PAGE_SIZE);
+				advanced_bio = true;
+			}
+
+			goto next;
+		}
+
+		/* Try to read from write buffer. The address is later checked
+		 * on the write buffer to prevent retrieving overwritten data.
+		 */
+		if (pblk_addr_in_cache(p)) {
+			if (!pblk_read_from_cache(pblk, bio, lba, p, i,
+								advanced_bio)) {
+				pblk_lookup_l2p_seq(pblk, &p, lba, 1);
+				goto retry;
+			}
+			WARN_ON(test_and_set_bit(i, read_bitmap));
+			meta_list[i].lba = cpu_to_le64(lba);
+			advanced_bio = true;
+#ifdef CONFIG_NVM_PBLK_DEBUG
+			atomic_long_inc(&pblk->cache_reads);
+#endif
+		} else {
+			/* Read from media non-cached sectors */
+			rqd->ppa_list[j++] = p;
+		}
+
+next:
+		if (advanced_bio)
+			bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
+	}
+
+	if (pblk_io_aligned(pblk, nr_secs))
+		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_SEQUENTIAL);
+	else
+		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	atomic_long_add(nr_secs, &pblk->inflight_reads);
+#endif
+}
+
+
+static void pblk_read_check_seq(struct pblk *pblk, struct nvm_rq *rqd,
+				sector_t blba)
+{
+	struct pblk_sec_meta *meta_lba_list = rqd->meta_list;
+	int nr_lbas = rqd->nr_ppas;
+	int i;
+
+	for (i = 0; i < nr_lbas; i++) {
+		u64 lba = le64_to_cpu(meta_lba_list[i].lba);
+
+		if (lba == ADDR_EMPTY)
+			continue;
+
+		if (lba != blba + i) {
+#ifdef CONFIG_NVM_PBLK_DEBUG
+			struct ppa_addr *p;
+
+			p = (nr_lbas == 1) ? &rqd->ppa_list[i] : &rqd->ppa_addr;
+			print_ppa(pblk, p, "seq", i);
+#endif
+			pblk_err(pblk, "corrupted read LBA (%llu/%llu)\n",
+							lba, (u64)blba + i);
+			WARN_ON(1);
+		}
+	}
+}
+
+/*
+ * There can be holes in the lba list.
+ */
+static void pblk_read_check_rand(struct pblk *pblk, struct nvm_rq *rqd,
+				 u64 *lba_list, int nr_lbas)
+{
+	struct pblk_sec_meta *meta_lba_list = rqd->meta_list;
+	int i, j;
+
+	for (i = 0, j = 0; i < nr_lbas; i++) {
+		u64 lba = lba_list[i];
+		u64 meta_lba;
+
+		if (lba == ADDR_EMPTY)
+			continue;
+
+		meta_lba = le64_to_cpu(meta_lba_list[j].lba);
+
+		if (lba != meta_lba) {
+#ifdef CONFIG_NVM_PBLK_DEBUG
+			struct ppa_addr *p;
+			int nr_ppas = rqd->nr_ppas;
+
+			p = (nr_ppas == 1) ? &rqd->ppa_list[j] : &rqd->ppa_addr;
+			print_ppa(pblk, p, "seq", j);
+#endif
+			pblk_err(pblk, "corrupted read LBA (%llu/%llu)\n",
+								lba, meta_lba);
+			WARN_ON(1);
+		}
+
+		j++;
+	}
+
+	WARN_ONCE(j != rqd->nr_ppas, "pblk: corrupted random request\n");
+}
+
+static void pblk_read_put_rqd_kref(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	struct ppa_addr *ppa_list;
+	int i;
+
+	ppa_list = (rqd->nr_ppas > 1) ? rqd->ppa_list : &rqd->ppa_addr;
+
+	for (i = 0; i < rqd->nr_ppas; i++) {
+		struct ppa_addr ppa = ppa_list[i];
+		struct pblk_line *line;
+
+		line = &pblk->lines[pblk_ppa_to_line(ppa)];
+		kref_put(&line->ref, pblk_line_put_wq);
+	}
+}
+
+static void pblk_end_user_read(struct bio *bio)
+{
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	WARN_ONCE(bio->bi_status, "pblk: corrupted read bio\n");
+#endif
+	bio_endio(bio);
+}
+
+static void __pblk_end_io_read(struct pblk *pblk, struct nvm_rq *rqd,
+			       bool put_line)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
+	struct bio *int_bio = rqd->bio;
+	unsigned long start_time = r_ctx->start_time;
+
+	generic_end_io_acct(dev->q, REQ_OP_READ, &pblk->disk->part0, start_time);
+
+	if (rqd->error)
+		pblk_log_read_err(pblk, rqd);
+
+	pblk_read_check_seq(pblk, rqd, r_ctx->lba);
+
+	if (int_bio)
+		bio_put(int_bio);
+
+	if (put_line)
+		pblk_read_put_rqd_kref(pblk, rqd);
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	atomic_long_add(rqd->nr_ppas, &pblk->sync_reads);
+	atomic_long_sub(rqd->nr_ppas, &pblk->inflight_reads);
+#endif
+
+	pblk_free_rqd(pblk, rqd, PBLK_READ);
+	atomic_dec(&pblk->inflight_io);
+}
+
+static void pblk_end_io_read(struct nvm_rq *rqd)
+{
+	struct pblk *pblk = rqd->private;
+	struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
+	struct bio *bio = (struct bio *)r_ctx->private;
+
+	pblk_end_user_read(bio);
+	__pblk_end_io_read(pblk, rqd, true);
+}
+
+static void pblk_end_partial_read(struct nvm_rq *rqd)
+{
+	struct pblk *pblk = rqd->private;
+	struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
+	struct pblk_pr_ctx *pr_ctx = r_ctx->private;
+	struct bio *new_bio = rqd->bio;
+	struct bio *bio = pr_ctx->orig_bio;
+	struct bio_vec src_bv, dst_bv;
+	struct pblk_sec_meta *meta_list = rqd->meta_list;
+	int bio_init_idx = pr_ctx->bio_init_idx;
+	unsigned long *read_bitmap = pr_ctx->bitmap;
+	int nr_secs = pr_ctx->orig_nr_secs;
+	int nr_holes = nr_secs - bitmap_weight(read_bitmap, nr_secs);
+	__le64 *lba_list_mem, *lba_list_media;
+	void *src_p, *dst_p;
+	int hole, i;
+
+	if (unlikely(nr_holes == 1)) {
+		struct ppa_addr ppa;
+
+		ppa = rqd->ppa_addr;
+		rqd->ppa_list = pr_ctx->ppa_ptr;
+		rqd->dma_ppa_list = pr_ctx->dma_ppa_list;
+		rqd->ppa_list[0] = ppa;
+	}
+
+	/* Re-use allocated memory for intermediate lbas */
+	lba_list_mem = (((void *)rqd->ppa_list) + pblk_dma_ppa_size);
+	lba_list_media = (((void *)rqd->ppa_list) + 2 * pblk_dma_ppa_size);
+
+	for (i = 0; i < nr_secs; i++) {
+		lba_list_media[i] = meta_list[i].lba;
+		meta_list[i].lba = lba_list_mem[i];
+	}
+
+	/* Fill the holes in the original bio */
+	i = 0;
+	hole = find_first_zero_bit(read_bitmap, nr_secs);
+	do {
+		int line_id = pblk_ppa_to_line(rqd->ppa_list[i]);
+		struct pblk_line *line = &pblk->lines[line_id];
+
+		kref_put(&line->ref, pblk_line_put);
+
+		meta_list[hole].lba = lba_list_media[i];
+
+		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_bio_pool);
+
+		hole = find_next_zero_bit(read_bitmap, nr_secs, hole + 1);
+	} while (hole < nr_secs);
+
+	bio_put(new_bio);
+	kfree(pr_ctx);
+
+	/* restore original request */
+	rqd->bio = NULL;
+	rqd->nr_ppas = nr_secs;
+
+	bio_endio(bio);
+	__pblk_end_io_read(pblk, rqd, false);
+}
+
+static int pblk_setup_partial_read(struct pblk *pblk, struct nvm_rq *rqd,
+			    unsigned int bio_init_idx,
+			    unsigned long *read_bitmap,
+			    int nr_holes)
+{
+	struct pblk_sec_meta *meta_list = rqd->meta_list;
+	struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
+	struct pblk_pr_ctx *pr_ctx;
+	struct bio *new_bio, *bio = r_ctx->private;
+	__le64 *lba_list_mem;
+	int nr_secs = rqd->nr_ppas;
+	int i;
+
+	/* Re-use allocated memory for intermediate lbas */
+	lba_list_mem = (((void *)rqd->ppa_list) + pblk_dma_ppa_size);
+
+	new_bio = bio_alloc(GFP_KERNEL, nr_holes);
+
+	if (pblk_bio_add_pages(pblk, new_bio, GFP_KERNEL, nr_holes))
+		goto fail_bio_put;
+
+	if (nr_holes != new_bio->bi_vcnt) {
+		WARN_ONCE(1, "pblk: malformed bio\n");
+		goto fail_free_pages;
+	}
+
+	pr_ctx = kmalloc(sizeof(struct pblk_pr_ctx), GFP_KERNEL);
+	if (!pr_ctx)
+		goto fail_free_pages;
+
+	for (i = 0; i < nr_secs; i++)
+		lba_list_mem[i] = meta_list[i].lba;
+
+	new_bio->bi_iter.bi_sector = 0; /* internal bio */
+	bio_set_op_attrs(new_bio, REQ_OP_READ, 0);
+
+	rqd->bio = new_bio;
+	rqd->nr_ppas = nr_holes;
+	rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
+
+	pr_ctx->ppa_ptr = NULL;
+	pr_ctx->orig_bio = bio;
+	bitmap_copy(pr_ctx->bitmap, read_bitmap, NVM_MAX_VLBA);
+	pr_ctx->bio_init_idx = bio_init_idx;
+	pr_ctx->orig_nr_secs = nr_secs;
+	r_ctx->private = pr_ctx;
+
+	if (unlikely(nr_holes == 1)) {
+		pr_ctx->ppa_ptr = rqd->ppa_list;
+		pr_ctx->dma_ppa_list = rqd->dma_ppa_list;
+		rqd->ppa_addr = rqd->ppa_list[0];
+	}
+	return 0;
+
+fail_free_pages:
+	pblk_bio_free_pages(pblk, new_bio, 0, new_bio->bi_vcnt);
+fail_bio_put:
+	bio_put(new_bio);
+
+	return -ENOMEM;
+}
+
+static int pblk_partial_read_bio(struct pblk *pblk, struct nvm_rq *rqd,
+				 unsigned int bio_init_idx,
+				 unsigned long *read_bitmap, int nr_secs)
+{
+	int nr_holes;
+	int ret;
+
+	nr_holes = nr_secs - bitmap_weight(read_bitmap, nr_secs);
+
+	if (pblk_setup_partial_read(pblk, rqd, bio_init_idx, read_bitmap,
+				    nr_holes))
+		return NVM_IO_ERR;
+
+	rqd->end_io = pblk_end_partial_read;
+
+	ret = pblk_submit_io(pblk, rqd);
+	if (ret) {
+		bio_put(rqd->bio);
+		pblk_err(pblk, "partial read IO submission failed\n");
+		goto err;
+	}
+
+	return NVM_IO_OK;
+
+err:
+	pblk_err(pblk, "failed to perform partial read\n");
+
+	/* Free allocated pages in new bio */
+	pblk_bio_free_pages(pblk, rqd->bio, 0, rqd->bio->bi_vcnt);
+	__pblk_end_io_read(pblk, rqd, false);
+	return NVM_IO_ERR;
+}
+
+static void pblk_read_rq(struct pblk *pblk, struct nvm_rq *rqd, struct bio *bio,
+			 sector_t lba, unsigned long *read_bitmap)
+{
+	struct pblk_sec_meta *meta_list = rqd->meta_list;
+	struct ppa_addr ppa;
+
+	pblk_lookup_l2p_seq(pblk, &ppa, lba, 1);
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	atomic_long_inc(&pblk->inflight_reads);
+#endif
+
+retry:
+	if (pblk_ppa_empty(ppa)) {
+		WARN_ON(test_and_set_bit(0, read_bitmap));
+		meta_list[0].lba = cpu_to_le64(ADDR_EMPTY);
+		return;
+	}
+
+	/* Try to read from write buffer. The address is later checked on the
+	 * write buffer to prevent retrieving overwritten data.
+	 */
+	if (pblk_addr_in_cache(ppa)) {
+		if (!pblk_read_from_cache(pblk, bio, lba, ppa, 0, 1)) {
+			pblk_lookup_l2p_seq(pblk, &ppa, lba, 1);
+			goto retry;
+		}
+
+		WARN_ON(test_and_set_bit(0, read_bitmap));
+		meta_list[0].lba = cpu_to_le64(lba);
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+		atomic_long_inc(&pblk->cache_reads);
+#endif
+	} else {
+		rqd->ppa_addr = ppa;
+	}
+
+	rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
+}
+
+int pblk_submit_read(struct pblk *pblk, struct bio *bio)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct request_queue *q = dev->q;
+	sector_t blba = pblk_get_lba(bio);
+	unsigned int nr_secs = pblk_get_secs(bio);
+	struct pblk_g_ctx *r_ctx;
+	struct nvm_rq *rqd;
+	unsigned int bio_init_idx;
+	DECLARE_BITMAP(read_bitmap, NVM_MAX_VLBA);
+	int ret = NVM_IO_ERR;
+
+	/* logic error: lba out-of-bounds. Ignore read request */
+	if (blba >= pblk->rl.nr_secs || nr_secs > PBLK_MAX_REQ_ADDRS) {
+		WARN(1, "pblk: read lba out of bounds (lba:%llu, nr:%d)\n",
+					(unsigned long long)blba, nr_secs);
+		return NVM_IO_ERR;
+	}
+
+	generic_start_io_acct(q, REQ_OP_READ, bio_sectors(bio),
+			      &pblk->disk->part0);
+
+	bitmap_zero(read_bitmap, nr_secs);
+
+	rqd = pblk_alloc_rqd(pblk, PBLK_READ);
+
+	rqd->opcode = NVM_OP_PREAD;
+	rqd->nr_ppas = nr_secs;
+	rqd->bio = NULL; /* cloned bio if needed */
+	rqd->private = pblk;
+	rqd->end_io = pblk_end_io_read;
+
+	r_ctx = nvm_rq_to_pdu(rqd);
+	r_ctx->start_time = jiffies;
+	r_ctx->lba = blba;
+	r_ctx->private = bio; /* original bio */
+
+	/* 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);
+
+	rqd->meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
+							&rqd->dma_meta_list);
+	if (!rqd->meta_list) {
+		pblk_err(pblk, "not able to allocate ppa list\n");
+		goto fail_rqd_free;
+	}
+
+	if (nr_secs > 1) {
+		rqd->ppa_list = rqd->meta_list + pblk_dma_meta_size;
+		rqd->dma_ppa_list = rqd->dma_meta_list + pblk_dma_meta_size;
+
+		pblk_read_ppalist_rq(pblk, rqd, bio, blba, read_bitmap);
+	} else {
+		pblk_read_rq(pblk, rqd, bio, blba, read_bitmap);
+	}
+
+	if (bitmap_full(read_bitmap, nr_secs)) {
+		atomic_inc(&pblk->inflight_io);
+		__pblk_end_io_read(pblk, rqd, false);
+		return NVM_IO_DONE;
+	}
+
+	/* All sectors are to be read from the device */
+	if (bitmap_empty(read_bitmap, rqd->nr_ppas)) {
+		struct bio *int_bio = NULL;
+
+		/* Clone read bio to deal with read errors internally */
+		int_bio = bio_clone_fast(bio, GFP_KERNEL, &pblk_bio_set);
+		if (!int_bio) {
+			pblk_err(pblk, "could not clone read bio\n");
+			goto fail_end_io;
+		}
+
+		rqd->bio = int_bio;
+
+		if (pblk_submit_io(pblk, rqd)) {
+			pblk_err(pblk, "read IO submission failed\n");
+			ret = NVM_IO_ERR;
+			goto fail_end_io;
+		}
+
+		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_partial_read_bio(pblk, rqd, bio_init_idx, read_bitmap,
+				    nr_secs);
+	if (ret)
+		goto fail_meta_free;
+
+	return NVM_IO_OK;
+
+fail_meta_free:
+	nvm_dev_dma_free(dev->parent, rqd->meta_list, rqd->dma_meta_list);
+fail_rqd_free:
+	pblk_free_rqd(pblk, rqd, PBLK_READ);
+	return ret;
+fail_end_io:
+	__pblk_end_io_read(pblk, rqd, false);
+	return ret;
+}
+
+static int read_ppalist_rq_gc(struct pblk *pblk, struct nvm_rq *rqd,
+			      struct pblk_line *line, u64 *lba_list,
+			      u64 *paddr_list_gc, unsigned int nr_secs)
+{
+	struct ppa_addr ppa_list_l2p[PBLK_MAX_REQ_ADDRS];
+	struct ppa_addr ppa_gc;
+	int valid_secs = 0;
+	int i;
+
+	pblk_lookup_l2p_rand(pblk, ppa_list_l2p, lba_list, nr_secs);
+
+	for (i = 0; i < nr_secs; i++) {
+		if (lba_list[i] == ADDR_EMPTY)
+			continue;
+
+		ppa_gc = addr_to_gen_ppa(pblk, paddr_list_gc[i], line->id);
+		if (!pblk_ppa_comp(ppa_list_l2p[i], ppa_gc)) {
+			paddr_list_gc[i] = lba_list[i] = ADDR_EMPTY;
+			continue;
+		}
+
+		rqd->ppa_list[valid_secs++] = ppa_list_l2p[i];
+	}
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	atomic_long_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,
+		      u64 paddr_gc)
+{
+	struct ppa_addr ppa_l2p, ppa_gc;
+	int valid_secs = 0;
+
+	if (lba == ADDR_EMPTY)
+		goto out;
+
+	/* logic error: lba out-of-bounds */
+	if (lba >= pblk->rl.nr_secs) {
+		WARN(1, "pblk: read lba out of bounds\n");
+		goto out;
+	}
+
+	spin_lock(&pblk->trans_lock);
+	ppa_l2p = pblk_trans_map_get(pblk, lba);
+	spin_unlock(&pblk->trans_lock);
+
+	ppa_gc = addr_to_gen_ppa(pblk, paddr_gc, line->id);
+	if (!pblk_ppa_comp(ppa_l2p, ppa_gc))
+		goto out;
+
+	rqd->ppa_addr = ppa_l2p;
+	valid_secs = 1;
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	atomic_long_inc(&pblk->inflight_reads);
+#endif
+
+out:
+	return valid_secs;
+}
+
+int pblk_submit_read_gc(struct pblk *pblk, struct pblk_gc_rq *gc_rq)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct bio *bio;
+	struct nvm_rq rqd;
+	int data_len;
+	int ret = NVM_IO_OK;
+
+	memset(&rqd, 0, sizeof(struct nvm_rq));
+
+	rqd.meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
+							&rqd.dma_meta_list);
+	if (!rqd.meta_list)
+		return -ENOMEM;
+
+	if (gc_rq->nr_secs > 1) {
+		rqd.ppa_list = rqd.meta_list + pblk_dma_meta_size;
+		rqd.dma_ppa_list = rqd.dma_meta_list + pblk_dma_meta_size;
+
+		gc_rq->secs_to_gc = read_ppalist_rq_gc(pblk, &rqd, gc_rq->line,
+							gc_rq->lba_list,
+							gc_rq->paddr_list,
+							gc_rq->nr_secs);
+		if (gc_rq->secs_to_gc == 1)
+			rqd.ppa_addr = rqd.ppa_list[0];
+	} else {
+		gc_rq->secs_to_gc = read_rq_gc(pblk, &rqd, gc_rq->line,
+							gc_rq->lba_list[0],
+							gc_rq->paddr_list[0]);
+	}
+
+	if (!(gc_rq->secs_to_gc))
+		goto out;
+
+	data_len = (gc_rq->secs_to_gc) * geo->csecs;
+	bio = pblk_bio_map_addr(pblk, gc_rq->data, gc_rq->secs_to_gc, data_len,
+						PBLK_VMALLOC_META, GFP_KERNEL);
+	if (IS_ERR(bio)) {
+		pblk_err(pblk, "could not allocate GC bio (%lu)\n",
+				PTR_ERR(bio));
+		goto err_free_dma;
+	}
+
+	bio->bi_iter.bi_sector = 0; /* internal bio */
+	bio_set_op_attrs(bio, REQ_OP_READ, 0);
+
+	rqd.opcode = NVM_OP_PREAD;
+	rqd.nr_ppas = gc_rq->secs_to_gc;
+	rqd.flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
+	rqd.bio = bio;
+
+	if (pblk_submit_io_sync(pblk, &rqd)) {
+		ret = -EIO;
+		pblk_err(pblk, "GC read request failed\n");
+		goto err_free_bio;
+	}
+
+	pblk_read_check_rand(pblk, &rqd, gc_rq->lba_list, gc_rq->nr_secs);
+
+	atomic_dec(&pblk->inflight_io);
+
+	if (rqd.error) {
+		atomic_long_inc(&pblk->read_failed_gc);
+#ifdef CONFIG_NVM_PBLK_DEBUG
+		pblk_print_failed_rqd(pblk, &rqd, rqd.error);
+#endif
+	}
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	atomic_long_add(gc_rq->secs_to_gc, &pblk->sync_reads);
+	atomic_long_add(gc_rq->secs_to_gc, &pblk->recov_gc_reads);
+	atomic_long_sub(gc_rq->secs_to_gc, &pblk->inflight_reads);
+#endif
+
+out:
+	nvm_dev_dma_free(dev->parent, rqd.meta_list, rqd.dma_meta_list);
+	return ret;
+
+err_free_bio:
+	bio_put(bio);
+err_free_dma:
+	nvm_dev_dma_free(dev->parent, rqd.meta_list, rqd.dma_meta_list);
+	return ret;
+}
diff --git a/src/kernel/linux/v4.19/drivers/lightnvm/pblk-recovery.c b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-recovery.c
new file mode 100644
index 0000000..df75d9c
--- /dev/null
+++ b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-recovery.c
@@ -0,0 +1,1011 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial: Javier Gonzalez <javier@cnexlabs.com>
+ *
+ * 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"
+
+int pblk_recov_check_emeta(struct pblk *pblk, struct line_emeta *emeta_buf)
+{
+	u32 crc;
+
+	crc = pblk_calc_emeta_crc(pblk, emeta_buf);
+	if (le32_to_cpu(emeta_buf->crc) != crc)
+		return 1;
+
+	if (le32_to_cpu(emeta_buf->header.identifier) != PBLK_MAGIC)
+		return 1;
+
+	return 0;
+}
+
+static int pblk_recov_l2p_from_emeta(struct pblk *pblk, struct pblk_line *line)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_emeta *emeta = line->emeta;
+	struct line_emeta *emeta_buf = emeta->buf;
+	__le64 *lba_list;
+	u64 data_start, data_end;
+	u64 nr_valid_lbas, nr_lbas = 0;
+	u64 i;
+
+	lba_list = emeta_to_lbas(pblk, emeta_buf);
+	if (!lba_list)
+		return 1;
+
+	data_start = pblk_line_smeta_start(pblk, line) + lm->smeta_sec;
+	data_end = line->emeta_ssec;
+	nr_valid_lbas = le64_to_cpu(emeta_buf->nr_valid_lbas);
+
+	for (i = data_start; i < data_end; i++) {
+		struct ppa_addr ppa;
+		int pos;
+
+		ppa = addr_to_gen_ppa(pblk, i, line->id);
+		pos = pblk_ppa_to_pos(geo, ppa);
+
+		/* Do not update bad blocks */
+		if (test_bit(pos, line->blk_bitmap))
+			continue;
+
+		if (le64_to_cpu(lba_list[i]) == ADDR_EMPTY) {
+			spin_lock(&line->lock);
+			if (test_and_set_bit(i, line->invalid_bitmap))
+				WARN_ONCE(1, "pblk: rec. double invalidate:\n");
+			else
+				le32_add_cpu(line->vsc, -1);
+			spin_unlock(&line->lock);
+
+			continue;
+		}
+
+		pblk_update_map(pblk, le64_to_cpu(lba_list[i]), ppa);
+		nr_lbas++;
+	}
+
+	if (nr_valid_lbas != nr_lbas)
+		pblk_err(pblk, "line %d - inconsistent lba list(%llu/%llu)\n",
+				line->id, nr_valid_lbas, nr_lbas);
+
+	line->left_msecs = 0;
+
+	return 0;
+}
+
+static int pblk_calc_sec_in_line(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;
+	int nr_bb = bitmap_weight(line->blk_bitmap, lm->blk_per_line);
+
+	return lm->sec_per_line - lm->smeta_sec - lm->emeta_sec[0] -
+				nr_bb * geo->clba;
+}
+
+struct pblk_recov_alloc {
+	struct ppa_addr *ppa_list;
+	struct pblk_sec_meta *meta_list;
+	struct nvm_rq *rqd;
+	void *data;
+	dma_addr_t dma_ppa_list;
+	dma_addr_t dma_meta_list;
+};
+
+static int pblk_recov_read_oob(struct pblk *pblk, struct pblk_line *line,
+			       struct pblk_recov_alloc p, u64 r_ptr)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct ppa_addr *ppa_list;
+	struct pblk_sec_meta *meta_list;
+	struct nvm_rq *rqd;
+	struct bio *bio;
+	void *data;
+	dma_addr_t dma_ppa_list, dma_meta_list;
+	u64 r_ptr_int;
+	int left_ppas;
+	int rq_ppas, rq_len;
+	int i, j;
+	int ret = 0;
+
+	ppa_list = p.ppa_list;
+	meta_list = p.meta_list;
+	rqd = p.rqd;
+	data = p.data;
+	dma_ppa_list = p.dma_ppa_list;
+	dma_meta_list = p.dma_meta_list;
+
+	left_ppas = line->cur_sec - r_ptr;
+	if (!left_ppas)
+		return 0;
+
+	r_ptr_int = r_ptr;
+
+next_read_rq:
+	memset(rqd, 0, pblk_g_rq_size);
+
+	rq_ppas = pblk_calc_secs(pblk, left_ppas, 0);
+	if (!rq_ppas)
+		rq_ppas = pblk->min_write_pgs;
+	rq_len = rq_ppas * geo->csecs;
+
+	bio = bio_map_kern(dev->q, data, rq_len, GFP_KERNEL);
+	if (IS_ERR(bio))
+		return PTR_ERR(bio);
+
+	bio->bi_iter.bi_sector = 0; /* internal bio */
+	bio_set_op_attrs(bio, REQ_OP_READ, 0);
+
+	rqd->bio = bio;
+	rqd->opcode = NVM_OP_PREAD;
+	rqd->meta_list = meta_list;
+	rqd->nr_ppas = rq_ppas;
+	rqd->ppa_list = ppa_list;
+	rqd->dma_ppa_list = dma_ppa_list;
+	rqd->dma_meta_list = dma_meta_list;
+
+	if (pblk_io_aligned(pblk, rq_ppas))
+		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_SEQUENTIAL);
+	else
+		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
+
+	for (i = 0; i < rqd->nr_ppas; ) {
+		struct ppa_addr ppa;
+		int pos;
+
+		ppa = addr_to_gen_ppa(pblk, r_ptr_int, line->id);
+		pos = pblk_ppa_to_pos(geo, ppa);
+
+		while (test_bit(pos, line->blk_bitmap)) {
+			r_ptr_int += pblk->min_write_pgs;
+			ppa = addr_to_gen_ppa(pblk, r_ptr_int, line->id);
+			pos = pblk_ppa_to_pos(geo, ppa);
+		}
+
+		for (j = 0; j < pblk->min_write_pgs; j++, i++, r_ptr_int++)
+			rqd->ppa_list[i] =
+				addr_to_gen_ppa(pblk, r_ptr_int, line->id);
+	}
+
+	/* If read fails, more padding is needed */
+	ret = pblk_submit_io_sync(pblk, rqd);
+	if (ret) {
+		pblk_err(pblk, "I/O submission failed: %d\n", ret);
+		return ret;
+	}
+
+	atomic_dec(&pblk->inflight_io);
+
+	/* At this point, the read should not fail. If it does, it is a problem
+	 * we cannot recover from here. Need FTL log.
+	 */
+	if (rqd->error && rqd->error != NVM_RSP_WARN_HIGHECC) {
+		pblk_err(pblk, "L2P recovery failed (%d)\n", rqd->error);
+		return -EINTR;
+	}
+
+	for (i = 0; i < rqd->nr_ppas; i++) {
+		u64 lba = le64_to_cpu(meta_list[i].lba);
+
+		if (lba == ADDR_EMPTY || lba > pblk->rl.nr_secs)
+			continue;
+
+		pblk_update_map(pblk, lba, rqd->ppa_list[i]);
+	}
+
+	left_ppas -= rq_ppas;
+	if (left_ppas > 0)
+		goto next_read_rq;
+
+	return 0;
+}
+
+static void pblk_recov_complete(struct kref *ref)
+{
+	struct pblk_pad_rq *pad_rq = container_of(ref, struct pblk_pad_rq, ref);
+
+	complete(&pad_rq->wait);
+}
+
+static void pblk_end_io_recov(struct nvm_rq *rqd)
+{
+	struct pblk_pad_rq *pad_rq = rqd->private;
+	struct pblk *pblk = pad_rq->pblk;
+
+	pblk_up_page(pblk, rqd->ppa_list, rqd->nr_ppas);
+
+	pblk_free_rqd(pblk, rqd, PBLK_WRITE_INT);
+
+	atomic_dec(&pblk->inflight_io);
+	kref_put(&pad_rq->ref, pblk_recov_complete);
+}
+
+static int pblk_recov_pad_oob(struct pblk *pblk, struct pblk_line *line,
+			      int left_ppas)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct ppa_addr *ppa_list;
+	struct pblk_sec_meta *meta_list;
+	struct pblk_pad_rq *pad_rq;
+	struct nvm_rq *rqd;
+	struct bio *bio;
+	void *data;
+	dma_addr_t dma_ppa_list, dma_meta_list;
+	__le64 *lba_list = emeta_to_lbas(pblk, line->emeta->buf);
+	u64 w_ptr = line->cur_sec;
+	int left_line_ppas, rq_ppas, rq_len;
+	int i, j;
+	int ret = 0;
+
+	spin_lock(&line->lock);
+	left_line_ppas = line->left_msecs;
+	spin_unlock(&line->lock);
+
+	pad_rq = kmalloc(sizeof(struct pblk_pad_rq), GFP_KERNEL);
+	if (!pad_rq)
+		return -ENOMEM;
+
+	data = vzalloc(array_size(pblk->max_write_pgs, geo->csecs));
+	if (!data) {
+		ret = -ENOMEM;
+		goto free_rq;
+	}
+
+	pad_rq->pblk = pblk;
+	init_completion(&pad_rq->wait);
+	kref_init(&pad_rq->ref);
+
+next_pad_rq:
+	rq_ppas = pblk_calc_secs(pblk, left_ppas, 0);
+	if (rq_ppas < pblk->min_write_pgs) {
+		pblk_err(pblk, "corrupted pad line %d\n", line->id);
+		goto fail_free_pad;
+	}
+
+	rq_len = rq_ppas * geo->csecs;
+
+	meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL, &dma_meta_list);
+	if (!meta_list) {
+		ret = -ENOMEM;
+		goto fail_free_pad;
+	}
+
+	ppa_list = (void *)(meta_list) + pblk_dma_meta_size;
+	dma_ppa_list = dma_meta_list + pblk_dma_meta_size;
+
+	bio = pblk_bio_map_addr(pblk, data, rq_ppas, rq_len,
+						PBLK_VMALLOC_META, GFP_KERNEL);
+	if (IS_ERR(bio)) {
+		ret = PTR_ERR(bio);
+		goto fail_free_meta;
+	}
+
+	bio->bi_iter.bi_sector = 0; /* internal bio */
+	bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+
+	rqd = pblk_alloc_rqd(pblk, PBLK_WRITE_INT);
+
+	rqd->bio = bio;
+	rqd->opcode = NVM_OP_PWRITE;
+	rqd->flags = pblk_set_progr_mode(pblk, PBLK_WRITE);
+	rqd->meta_list = meta_list;
+	rqd->nr_ppas = rq_ppas;
+	rqd->ppa_list = ppa_list;
+	rqd->dma_ppa_list = dma_ppa_list;
+	rqd->dma_meta_list = dma_meta_list;
+	rqd->end_io = pblk_end_io_recov;
+	rqd->private = pad_rq;
+
+	for (i = 0; i < rqd->nr_ppas; ) {
+		struct ppa_addr ppa;
+		int pos;
+
+		w_ptr = pblk_alloc_page(pblk, line, pblk->min_write_pgs);
+		ppa = addr_to_gen_ppa(pblk, w_ptr, line->id);
+		pos = pblk_ppa_to_pos(geo, ppa);
+
+		while (test_bit(pos, line->blk_bitmap)) {
+			w_ptr += pblk->min_write_pgs;
+			ppa = addr_to_gen_ppa(pblk, w_ptr, line->id);
+			pos = pblk_ppa_to_pos(geo, ppa);
+		}
+
+		for (j = 0; j < pblk->min_write_pgs; j++, i++, w_ptr++) {
+			struct ppa_addr dev_ppa;
+			__le64 addr_empty = cpu_to_le64(ADDR_EMPTY);
+
+			dev_ppa = addr_to_gen_ppa(pblk, w_ptr, line->id);
+
+			pblk_map_invalidate(pblk, dev_ppa);
+			lba_list[w_ptr] = meta_list[i].lba = addr_empty;
+			rqd->ppa_list[i] = dev_ppa;
+		}
+	}
+
+	kref_get(&pad_rq->ref);
+	pblk_down_page(pblk, rqd->ppa_list, rqd->nr_ppas);
+
+	ret = pblk_submit_io(pblk, rqd);
+	if (ret) {
+		pblk_err(pblk, "I/O submission failed: %d\n", ret);
+		pblk_up_page(pblk, rqd->ppa_list, rqd->nr_ppas);
+		goto fail_free_bio;
+	}
+
+	left_line_ppas -= rq_ppas;
+	left_ppas -= rq_ppas;
+	if (left_ppas && left_line_ppas)
+		goto next_pad_rq;
+
+	kref_put(&pad_rq->ref, pblk_recov_complete);
+
+	if (!wait_for_completion_io_timeout(&pad_rq->wait,
+				msecs_to_jiffies(PBLK_COMMAND_TIMEOUT_MS))) {
+		pblk_err(pblk, "pad write timed out\n");
+		ret = -ETIME;
+	}
+
+	if (!pblk_line_is_full(line))
+		pblk_err(pblk, "corrupted padded line: %d\n", line->id);
+
+	vfree(data);
+free_rq:
+	kfree(pad_rq);
+	return ret;
+
+fail_free_bio:
+	bio_put(bio);
+fail_free_meta:
+	nvm_dev_dma_free(dev->parent, meta_list, dma_meta_list);
+fail_free_pad:
+	kfree(pad_rq);
+	vfree(data);
+	return ret;
+}
+
+/* When this function is called, it means that not all upper pages have been
+ * written in a page that contains valid data. In order to recover this data, we
+ * first find the write pointer on the device, then we pad all necessary
+ * sectors, and finally attempt to read the valid data
+ */
+static int pblk_recov_scan_all_oob(struct pblk *pblk, struct pblk_line *line,
+				   struct pblk_recov_alloc p)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct ppa_addr *ppa_list;
+	struct pblk_sec_meta *meta_list;
+	struct nvm_rq *rqd;
+	struct bio *bio;
+	void *data;
+	dma_addr_t dma_ppa_list, dma_meta_list;
+	u64 w_ptr = 0, r_ptr;
+	int rq_ppas, rq_len;
+	int i, j;
+	int ret = 0;
+	int rec_round;
+	int left_ppas = pblk_calc_sec_in_line(pblk, line) - line->cur_sec;
+
+	ppa_list = p.ppa_list;
+	meta_list = p.meta_list;
+	rqd = p.rqd;
+	data = p.data;
+	dma_ppa_list = p.dma_ppa_list;
+	dma_meta_list = p.dma_meta_list;
+
+	/* we could recover up until the line write pointer */
+	r_ptr = line->cur_sec;
+	rec_round = 0;
+
+next_rq:
+	memset(rqd, 0, pblk_g_rq_size);
+
+	rq_ppas = pblk_calc_secs(pblk, left_ppas, 0);
+	if (!rq_ppas)
+		rq_ppas = pblk->min_write_pgs;
+	rq_len = rq_ppas * geo->csecs;
+
+	bio = bio_map_kern(dev->q, data, rq_len, GFP_KERNEL);
+	if (IS_ERR(bio))
+		return PTR_ERR(bio);
+
+	bio->bi_iter.bi_sector = 0; /* internal bio */
+	bio_set_op_attrs(bio, REQ_OP_READ, 0);
+
+	rqd->bio = bio;
+	rqd->opcode = NVM_OP_PREAD;
+	rqd->meta_list = meta_list;
+	rqd->nr_ppas = rq_ppas;
+	rqd->ppa_list = ppa_list;
+	rqd->dma_ppa_list = dma_ppa_list;
+	rqd->dma_meta_list = dma_meta_list;
+
+	if (pblk_io_aligned(pblk, rq_ppas))
+		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_SEQUENTIAL);
+	else
+		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
+
+	for (i = 0; i < rqd->nr_ppas; ) {
+		struct ppa_addr ppa;
+		int pos;
+
+		w_ptr = pblk_alloc_page(pblk, line, pblk->min_write_pgs);
+		ppa = addr_to_gen_ppa(pblk, w_ptr, line->id);
+		pos = pblk_ppa_to_pos(geo, ppa);
+
+		while (test_bit(pos, line->blk_bitmap)) {
+			w_ptr += pblk->min_write_pgs;
+			ppa = addr_to_gen_ppa(pblk, w_ptr, line->id);
+			pos = pblk_ppa_to_pos(geo, ppa);
+		}
+
+		for (j = 0; j < pblk->min_write_pgs; j++, i++, w_ptr++)
+			rqd->ppa_list[i] =
+				addr_to_gen_ppa(pblk, w_ptr, line->id);
+	}
+
+	ret = pblk_submit_io_sync(pblk, rqd);
+	if (ret) {
+		pblk_err(pblk, "I/O submission failed: %d\n", ret);
+		return ret;
+	}
+
+	atomic_dec(&pblk->inflight_io);
+
+	/* This should not happen since the read failed during normal recovery,
+	 * but the media works funny sometimes...
+	 */
+	if (!rec_round++ && !rqd->error) {
+		rec_round = 0;
+		for (i = 0; i < rqd->nr_ppas; i++, r_ptr++) {
+			u64 lba = le64_to_cpu(meta_list[i].lba);
+
+			if (lba == ADDR_EMPTY || lba > pblk->rl.nr_secs)
+				continue;
+
+			pblk_update_map(pblk, lba, rqd->ppa_list[i]);
+		}
+	}
+
+	/* Reached the end of the written line */
+	if (rqd->error == NVM_RSP_ERR_EMPTYPAGE) {
+		int pad_secs, nr_error_bits, bit;
+		int ret;
+
+		bit = find_first_bit((void *)&rqd->ppa_status, rqd->nr_ppas);
+		nr_error_bits = rqd->nr_ppas - bit;
+
+		/* Roll back failed sectors */
+		line->cur_sec -= nr_error_bits;
+		line->left_msecs += nr_error_bits;
+		bitmap_clear(line->map_bitmap, line->cur_sec, nr_error_bits);
+
+		pad_secs = pblk_pad_distance(pblk);
+		if (pad_secs > line->left_msecs)
+			pad_secs = line->left_msecs;
+
+		ret = pblk_recov_pad_oob(pblk, line, pad_secs);
+		if (ret)
+			pblk_err(pblk, "OOB padding failed (err:%d)\n", ret);
+
+		ret = pblk_recov_read_oob(pblk, line, p, r_ptr);
+		if (ret)
+			pblk_err(pblk, "OOB read failed (err:%d)\n", ret);
+
+		left_ppas = 0;
+	}
+
+	left_ppas -= rq_ppas;
+	if (left_ppas > 0)
+		goto next_rq;
+
+	return ret;
+}
+
+static int pblk_recov_scan_oob(struct pblk *pblk, struct pblk_line *line,
+			       struct pblk_recov_alloc p, int *done)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct ppa_addr *ppa_list;
+	struct pblk_sec_meta *meta_list;
+	struct nvm_rq *rqd;
+	struct bio *bio;
+	void *data;
+	dma_addr_t dma_ppa_list, dma_meta_list;
+	u64 paddr;
+	int rq_ppas, rq_len;
+	int i, j;
+	int ret = 0;
+	int left_ppas = pblk_calc_sec_in_line(pblk, line);
+
+	ppa_list = p.ppa_list;
+	meta_list = p.meta_list;
+	rqd = p.rqd;
+	data = p.data;
+	dma_ppa_list = p.dma_ppa_list;
+	dma_meta_list = p.dma_meta_list;
+
+	*done = 1;
+
+next_rq:
+	memset(rqd, 0, pblk_g_rq_size);
+
+	rq_ppas = pblk_calc_secs(pblk, left_ppas, 0);
+	if (!rq_ppas)
+		rq_ppas = pblk->min_write_pgs;
+	rq_len = rq_ppas * geo->csecs;
+
+	bio = bio_map_kern(dev->q, data, rq_len, GFP_KERNEL);
+	if (IS_ERR(bio))
+		return PTR_ERR(bio);
+
+	bio->bi_iter.bi_sector = 0; /* internal bio */
+	bio_set_op_attrs(bio, REQ_OP_READ, 0);
+
+	rqd->bio = bio;
+	rqd->opcode = NVM_OP_PREAD;
+	rqd->meta_list = meta_list;
+	rqd->nr_ppas = rq_ppas;
+	rqd->ppa_list = ppa_list;
+	rqd->dma_ppa_list = dma_ppa_list;
+	rqd->dma_meta_list = dma_meta_list;
+
+	if (pblk_io_aligned(pblk, rq_ppas))
+		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_SEQUENTIAL);
+	else
+		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
+
+	for (i = 0; i < rqd->nr_ppas; ) {
+		struct ppa_addr ppa;
+		int pos;
+
+		paddr = pblk_alloc_page(pblk, line, pblk->min_write_pgs);
+		ppa = addr_to_gen_ppa(pblk, paddr, line->id);
+		pos = pblk_ppa_to_pos(geo, ppa);
+
+		while (test_bit(pos, line->blk_bitmap)) {
+			paddr += pblk->min_write_pgs;
+			ppa = addr_to_gen_ppa(pblk, paddr, line->id);
+			pos = pblk_ppa_to_pos(geo, ppa);
+		}
+
+		for (j = 0; j < pblk->min_write_pgs; j++, i++, paddr++)
+			rqd->ppa_list[i] =
+				addr_to_gen_ppa(pblk, paddr, line->id);
+	}
+
+	ret = pblk_submit_io_sync(pblk, rqd);
+	if (ret) {
+		pblk_err(pblk, "I/O submission failed: %d\n", ret);
+		bio_put(bio);
+		return ret;
+	}
+
+	atomic_dec(&pblk->inflight_io);
+
+	/* Reached the end of the written line */
+	if (rqd->error) {
+		int nr_error_bits, bit;
+
+		bit = find_first_bit((void *)&rqd->ppa_status, rqd->nr_ppas);
+		nr_error_bits = rqd->nr_ppas - bit;
+
+		/* Roll back failed sectors */
+		line->cur_sec -= nr_error_bits;
+		line->left_msecs += nr_error_bits;
+		bitmap_clear(line->map_bitmap, line->cur_sec, nr_error_bits);
+
+		left_ppas = 0;
+		rqd->nr_ppas = bit;
+
+		if (rqd->error != NVM_RSP_ERR_EMPTYPAGE)
+			*done = 0;
+	}
+
+	for (i = 0; i < rqd->nr_ppas; i++) {
+		u64 lba = le64_to_cpu(meta_list[i].lba);
+
+		if (lba == ADDR_EMPTY || lba > pblk->rl.nr_secs)
+			continue;
+
+		pblk_update_map(pblk, lba, rqd->ppa_list[i]);
+	}
+
+	left_ppas -= rq_ppas;
+	if (left_ppas > 0)
+		goto next_rq;
+
+	return ret;
+}
+
+/* Scan line for lbas on out of bound area */
+static int pblk_recov_l2p_from_oob(struct pblk *pblk, struct pblk_line *line)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct nvm_rq *rqd;
+	struct ppa_addr *ppa_list;
+	struct pblk_sec_meta *meta_list;
+	struct pblk_recov_alloc p;
+	void *data;
+	dma_addr_t dma_ppa_list, dma_meta_list;
+	int done, ret = 0;
+
+	meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL, &dma_meta_list);
+	if (!meta_list)
+		return -ENOMEM;
+
+	ppa_list = (void *)(meta_list) + pblk_dma_meta_size;
+	dma_ppa_list = dma_meta_list + pblk_dma_meta_size;
+
+	data = kcalloc(pblk->max_write_pgs, geo->csecs, GFP_KERNEL);
+	if (!data) {
+		ret = -ENOMEM;
+		goto free_meta_list;
+	}
+
+	rqd = pblk_alloc_rqd(pblk, PBLK_READ);
+
+	p.ppa_list = ppa_list;
+	p.meta_list = meta_list;
+	p.rqd = rqd;
+	p.data = data;
+	p.dma_ppa_list = dma_ppa_list;
+	p.dma_meta_list = dma_meta_list;
+
+	ret = pblk_recov_scan_oob(pblk, line, p, &done);
+	if (ret) {
+		pblk_err(pblk, "could not recover L2P from OOB\n");
+		goto out;
+	}
+
+	if (!done) {
+		ret = pblk_recov_scan_all_oob(pblk, line, p);
+		if (ret) {
+			pblk_err(pblk, "could not recover L2P from OOB\n");
+			goto out;
+		}
+	}
+
+	if (pblk_line_is_full(line))
+		pblk_line_recov_close(pblk, line);
+
+out:
+	kfree(data);
+free_meta_list:
+	nvm_dev_dma_free(dev->parent, meta_list, dma_meta_list);
+
+	return ret;
+}
+
+/* Insert lines ordered by sequence number (seq_num) on list */
+static void pblk_recov_line_add_ordered(struct list_head *head,
+					struct pblk_line *line)
+{
+	struct pblk_line *t = NULL;
+
+	list_for_each_entry(t, head, list)
+		if (t->seq_nr > line->seq_nr)
+			break;
+
+	__list_add(&line->list, t->list.prev, &t->list);
+}
+
+static u64 pblk_line_emeta_start(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;
+	unsigned int emeta_secs;
+	u64 emeta_start;
+	struct ppa_addr ppa;
+	int pos;
+
+	emeta_secs = lm->emeta_sec[0];
+	emeta_start = lm->sec_per_line;
+
+	while (emeta_secs) {
+		emeta_start--;
+		ppa = addr_to_gen_ppa(pblk, emeta_start, line->id);
+		pos = pblk_ppa_to_pos(geo, ppa);
+		if (!test_bit(pos, line->blk_bitmap))
+			emeta_secs--;
+	}
+
+	return emeta_start;
+}
+
+static int pblk_recov_check_line_version(struct pblk *pblk,
+					 struct line_emeta *emeta)
+{
+	struct line_header *header = &emeta->header;
+
+	if (header->version_major != EMETA_VERSION_MAJOR) {
+		pblk_err(pblk, "line major version mismatch: %d, expected: %d\n",
+			 header->version_major, EMETA_VERSION_MAJOR);
+		return 1;
+	}
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	if (header->version_minor > EMETA_VERSION_MINOR)
+		pblk_info(pblk, "newer line minor version found: %d\n",
+				header->version_minor);
+#endif
+
+	return 0;
+}
+
+static void pblk_recov_wa_counters(struct pblk *pblk,
+				   struct line_emeta *emeta)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct line_header *header = &emeta->header;
+	struct wa_counters *wa = emeta_to_wa(lm, emeta);
+
+	/* WA counters were introduced in emeta version 0.2 */
+	if (header->version_major > 0 || header->version_minor >= 2) {
+		u64 user = le64_to_cpu(wa->user);
+		u64 pad = le64_to_cpu(wa->pad);
+		u64 gc = le64_to_cpu(wa->gc);
+
+		atomic64_set(&pblk->user_wa, user);
+		atomic64_set(&pblk->pad_wa, pad);
+		atomic64_set(&pblk->gc_wa, gc);
+
+		pblk->user_rst_wa = user;
+		pblk->pad_rst_wa = pad;
+		pblk->gc_rst_wa = gc;
+	}
+}
+
+static int pblk_line_was_written(struct pblk_line *line,
+			    struct pblk *pblk)
+{
+
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct nvm_chk_meta *chunk;
+	struct ppa_addr bppa;
+	int smeta_blk;
+
+	if (line->state == PBLK_LINESTATE_BAD)
+		return 0;
+
+	smeta_blk = find_first_zero_bit(line->blk_bitmap, lm->blk_per_line);
+	if (smeta_blk >= lm->blk_per_line)
+		return 0;
+
+	bppa = pblk->luns[smeta_blk].bppa;
+	chunk = &line->chks[pblk_ppa_to_pos(geo, bppa)];
+
+	if (chunk->state & NVM_CHK_ST_FREE)
+		return 0;
+
+	return 1;
+}
+
+struct pblk_line *pblk_recov_l2p(struct pblk *pblk)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line *line, *tline, *data_line = NULL;
+	struct pblk_smeta *smeta;
+	struct pblk_emeta *emeta;
+	struct line_smeta *smeta_buf;
+	int found_lines = 0, recovered_lines = 0, open_lines = 0;
+	int is_next = 0;
+	int meta_line;
+	int i, valid_uuid = 0;
+	LIST_HEAD(recov_list);
+
+	/* TODO: Implement FTL snapshot */
+
+	/* Scan recovery - takes place when FTL snapshot fails */
+	spin_lock(&l_mg->free_lock);
+	meta_line = find_first_zero_bit(&l_mg->meta_bitmap, PBLK_DATA_LINES);
+	set_bit(meta_line, &l_mg->meta_bitmap);
+	smeta = l_mg->sline_meta[meta_line];
+	emeta = l_mg->eline_meta[meta_line];
+	smeta_buf = (struct line_smeta *)smeta;
+	spin_unlock(&l_mg->free_lock);
+
+	/* Order data lines using their sequence number */
+	for (i = 0; i < l_mg->nr_lines; i++) {
+		u32 crc;
+
+		line = &pblk->lines[i];
+
+		memset(smeta, 0, lm->smeta_len);
+		line->smeta = smeta;
+		line->lun_bitmap = ((void *)(smeta_buf)) +
+						sizeof(struct line_smeta);
+
+		if (!pblk_line_was_written(line, pblk))
+			continue;
+
+		/* Lines that cannot be read are assumed as not written here */
+		if (pblk_line_read_smeta(pblk, line))
+			continue;
+
+		crc = pblk_calc_smeta_crc(pblk, smeta_buf);
+		if (le32_to_cpu(smeta_buf->crc) != crc)
+			continue;
+
+		if (le32_to_cpu(smeta_buf->header.identifier) != PBLK_MAGIC)
+			continue;
+
+		if (smeta_buf->header.version_major != SMETA_VERSION_MAJOR) {
+			pblk_err(pblk, "found incompatible line version %u\n",
+					smeta_buf->header.version_major);
+			return ERR_PTR(-EINVAL);
+		}
+
+		/* The first valid instance uuid is used for initialization */
+		if (!valid_uuid) {
+			memcpy(pblk->instance_uuid, smeta_buf->header.uuid, 16);
+			valid_uuid = 1;
+		}
+
+		if (memcmp(pblk->instance_uuid, smeta_buf->header.uuid, 16)) {
+			pblk_debug(pblk, "ignore line %u due to uuid mismatch\n",
+					i);
+			continue;
+		}
+
+		/* Update line metadata */
+		spin_lock(&line->lock);
+		line->id = le32_to_cpu(smeta_buf->header.id);
+		line->type = le16_to_cpu(smeta_buf->header.type);
+		line->seq_nr = le64_to_cpu(smeta_buf->seq_nr);
+		spin_unlock(&line->lock);
+
+		/* Update general metadata */
+		spin_lock(&l_mg->free_lock);
+		if (line->seq_nr >= l_mg->d_seq_nr)
+			l_mg->d_seq_nr = line->seq_nr + 1;
+		l_mg->nr_free_lines--;
+		spin_unlock(&l_mg->free_lock);
+
+		if (pblk_line_recov_alloc(pblk, line))
+			goto out;
+
+		pblk_recov_line_add_ordered(&recov_list, line);
+		found_lines++;
+		pblk_debug(pblk, "recovering data line %d, seq:%llu\n",
+						line->id, smeta_buf->seq_nr);
+	}
+
+	if (!found_lines) {
+		pblk_setup_uuid(pblk);
+
+		spin_lock(&l_mg->free_lock);
+		WARN_ON_ONCE(!test_and_clear_bit(meta_line,
+							&l_mg->meta_bitmap));
+		spin_unlock(&l_mg->free_lock);
+
+		goto out;
+	}
+
+	/* Verify closed blocks and recover this portion of L2P table*/
+	list_for_each_entry_safe(line, tline, &recov_list, list) {
+		recovered_lines++;
+
+		line->emeta_ssec = pblk_line_emeta_start(pblk, line);
+		line->emeta = emeta;
+		memset(line->emeta->buf, 0, lm->emeta_len[0]);
+
+		if (pblk_line_read_emeta(pblk, line, line->emeta->buf)) {
+			pblk_recov_l2p_from_oob(pblk, line);
+			goto next;
+		}
+
+		if (pblk_recov_check_emeta(pblk, line->emeta->buf)) {
+			pblk_recov_l2p_from_oob(pblk, line);
+			goto next;
+		}
+
+		if (pblk_recov_check_line_version(pblk, line->emeta->buf))
+			return ERR_PTR(-EINVAL);
+
+		pblk_recov_wa_counters(pblk, line->emeta->buf);
+
+		if (pblk_recov_l2p_from_emeta(pblk, line))
+			pblk_recov_l2p_from_oob(pblk, line);
+
+next:
+		if (pblk_line_is_full(line)) {
+			struct list_head *move_list;
+
+			spin_lock(&line->lock);
+			line->state = PBLK_LINESTATE_CLOSED;
+			move_list = pblk_line_gc_list(pblk, line);
+			spin_unlock(&line->lock);
+
+			spin_lock(&l_mg->gc_lock);
+			list_move_tail(&line->list, move_list);
+			spin_unlock(&l_mg->gc_lock);
+
+			kfree(line->map_bitmap);
+			line->map_bitmap = NULL;
+			line->smeta = NULL;
+			line->emeta = NULL;
+		} else {
+			if (open_lines > 1)
+				pblk_err(pblk, "failed to recover L2P\n");
+
+			open_lines++;
+			line->meta_line = meta_line;
+			data_line = line;
+		}
+	}
+
+	if (!open_lines) {
+		spin_lock(&l_mg->free_lock);
+		WARN_ON_ONCE(!test_and_clear_bit(meta_line,
+							&l_mg->meta_bitmap));
+		spin_unlock(&l_mg->free_lock);
+		pblk_line_replace_data(pblk);
+	} else {
+		spin_lock(&l_mg->free_lock);
+		/* Allocate next line for preparation */
+		l_mg->data_next = pblk_line_get(pblk);
+		if (l_mg->data_next) {
+			l_mg->data_next->seq_nr = l_mg->d_seq_nr++;
+			l_mg->data_next->type = PBLK_LINETYPE_DATA;
+			is_next = 1;
+		}
+		spin_unlock(&l_mg->free_lock);
+	}
+
+	if (is_next)
+		pblk_line_erase(pblk, l_mg->data_next);
+
+out:
+	if (found_lines != recovered_lines)
+		pblk_err(pblk, "failed to recover all found lines %d/%d\n",
+						found_lines, recovered_lines);
+
+	return data_line;
+}
+
+/*
+ * Pad current line
+ */
+int pblk_recov_pad(struct pblk *pblk)
+{
+	struct pblk_line *line;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	int left_msecs;
+	int ret = 0;
+
+	spin_lock(&l_mg->free_lock);
+	line = l_mg->data_line;
+	left_msecs = line->left_msecs;
+	spin_unlock(&l_mg->free_lock);
+
+	ret = pblk_recov_pad_oob(pblk, line, left_msecs);
+	if (ret) {
+		pblk_err(pblk, "tear down padding failed (%d)\n", ret);
+		return ret;
+	}
+
+	pblk_line_close_meta(pblk, line);
+	return ret;
+}
diff --git a/src/kernel/linux/v4.19/drivers/lightnvm/pblk-rl.c b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-rl.c
new file mode 100644
index 0000000..6a0616a
--- /dev/null
+++ b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-rl.c
@@ -0,0 +1,250 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@cnexlabs.com>
+ *                  Matias Bjorling <matias@cnexlabs.com>
+ *
+ * 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_is_limit(struct pblk_rl *rl)
+{
+	int rb_space;
+
+	rb_space = atomic_read(&rl->rb_space);
+
+	return (rb_space == 0);
+}
+
+int pblk_rl_user_may_insert(struct pblk_rl *rl, int nr_entries)
+{
+	int rb_user_cnt = atomic_read(&rl->rb_user_cnt);
+	int rb_space = atomic_read(&rl->rb_space);
+
+	if (unlikely(rb_space >= 0) && (rb_space - nr_entries < 0))
+		return NVM_IO_ERR;
+
+	if (rb_user_cnt >= rl->rb_user_max)
+		return NVM_IO_REQUEUE;
+
+	return NVM_IO_OK;
+}
+
+void pblk_rl_inserted(struct pblk_rl *rl, int nr_entries)
+{
+	int rb_space = atomic_read(&rl->rb_space);
+
+	if (unlikely(rb_space >= 0))
+		atomic_sub(nr_entries, &rl->rb_space);
+}
+
+int pblk_rl_gc_may_insert(struct pblk_rl *rl, int nr_entries)
+{
+	int rb_gc_cnt = atomic_read(&rl->rb_gc_cnt);
+	int rb_user_active;
+
+	/* If there is no user I/O let GC take over space on the write buffer */
+	rb_user_active = READ_ONCE(rl->rb_user_active);
+	return (!(rb_gc_cnt >= rl->rb_gc_max && rb_user_active));
+}
+
+void pblk_rl_user_in(struct pblk_rl *rl, int nr_entries)
+{
+	atomic_add(nr_entries, &rl->rb_user_cnt);
+
+	/* 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_werr_line_in(struct pblk_rl *rl)
+{
+	atomic_inc(&rl->werr_lines);
+}
+
+void pblk_rl_werr_line_out(struct pblk_rl *rl)
+{
+	atomic_dec(&rl->werr_lines);
+}
+
+void pblk_rl_gc_in(struct pblk_rl *rl, int nr_entries)
+{
+	atomic_add(nr_entries, &rl->rb_gc_cnt);
+}
+
+void pblk_rl_out(struct pblk_rl *rl, int nr_user, int nr_gc)
+{
+	atomic_sub(nr_user, &rl->rb_user_cnt);
+	atomic_sub(nr_gc, &rl->rb_gc_cnt);
+}
+
+unsigned long pblk_rl_nr_free_blks(struct pblk_rl *rl)
+{
+	return atomic_read(&rl->free_blocks);
+}
+
+unsigned long pblk_rl_nr_user_free_blks(struct pblk_rl *rl)
+{
+	return atomic_read(&rl->free_user_blocks);
+}
+
+static void __pblk_rl_update_rates(struct pblk_rl *rl,
+				   unsigned long free_blocks)
+{
+	struct pblk *pblk = container_of(rl, struct pblk, rl);
+	int max = rl->rb_budget;
+	int werr_gc_needed = atomic_read(&rl->werr_lines);
+
+	if (free_blocks >= rl->high) {
+		if (werr_gc_needed) {
+			/* Allocate a small budget for recovering
+			 * lines with write errors
+			 */
+			rl->rb_gc_max = 1 << rl->rb_windows_pw;
+			rl->rb_user_max = max - rl->rb_gc_max;
+			rl->rb_state = PBLK_RL_WERR;
+		} else {
+			rl->rb_user_max = max;
+			rl->rb_gc_max = 0;
+			rl->rb_state = PBLK_RL_OFF;
+		}
+	} else if (free_blocks < rl->high) {
+		int shift = rl->high_pw - rl->rb_windows_pw;
+		int user_windows = free_blocks >> shift;
+		int user_max = user_windows << PBLK_MAX_REQ_ADDRS_PW;
+
+		rl->rb_user_max = user_max;
+		rl->rb_gc_max = max - user_max;
+
+		if (free_blocks <= rl->rsv_blocks) {
+			rl->rb_user_max = 0;
+			rl->rb_gc_max = max;
+		}
+
+		/* In the worst case, we will need to GC lines in the low list
+		 * (high valid sector count). If there are lines to GC on high
+		 * or mid lists, these will be prioritized
+		 */
+		rl->rb_state = PBLK_RL_LOW;
+	}
+
+	if (rl->rb_state != PBLK_RL_OFF)
+		pblk_gc_should_start(pblk);
+	else
+		pblk_gc_should_stop(pblk);
+}
+
+void pblk_rl_update_rates(struct pblk_rl *rl)
+{
+	__pblk_rl_update_rates(rl, pblk_rl_nr_user_free_blks(rl));
+}
+
+void pblk_rl_free_lines_inc(struct pblk_rl *rl, struct pblk_line *line)
+{
+	int blk_in_line = atomic_read(&line->blk_in_line);
+	int free_blocks;
+
+	atomic_add(blk_in_line, &rl->free_blocks);
+	free_blocks = atomic_add_return(blk_in_line, &rl->free_user_blocks);
+
+	__pblk_rl_update_rates(rl, free_blocks);
+}
+
+void pblk_rl_free_lines_dec(struct pblk_rl *rl, struct pblk_line *line,
+			    bool used)
+{
+	int blk_in_line = atomic_read(&line->blk_in_line);
+	int free_blocks;
+
+	atomic_sub(blk_in_line, &rl->free_blocks);
+
+	if (used)
+		free_blocks = atomic_sub_return(blk_in_line,
+							&rl->free_user_blocks);
+	else
+		free_blocks = atomic_read(&rl->free_user_blocks);
+
+	__pblk_rl_update_rates(rl, free_blocks);
+}
+
+int pblk_rl_high_thrs(struct pblk_rl *rl)
+{
+	return rl->high;
+}
+
+int pblk_rl_max_io(struct pblk_rl *rl)
+{
+	return rl->rb_max_io;
+}
+
+static void pblk_rl_u_timer(struct timer_list *t)
+{
+	struct pblk_rl *rl = from_timer(rl, t, u_timer);
+
+	/* 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)
+{
+	struct pblk *pblk = container_of(rl, struct pblk, rl);
+	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;
+	int min_blocks = lm->blk_per_line * PBLK_GC_RSV_LINE;
+	int sec_meta, blk_meta;
+
+	unsigned int rb_windows;
+
+	/* Consider sectors used for metadata */
+	sec_meta = (lm->smeta_sec + lm->emeta_sec[0]) * l_mg->nr_free_lines;
+	blk_meta = DIV_ROUND_UP(sec_meta, geo->clba);
+
+	rl->high = pblk->op_blks - blk_meta - lm->blk_per_line;
+	rl->high_pw = get_count_order(rl->high);
+
+	rl->rsv_blocks = min_blocks;
+
+	/* This will always be a power-of-2 */
+	rb_windows = budget / PBLK_MAX_REQ_ADDRS;
+	rl->rb_windows_pw = get_count_order(rb_windows);
+
+	/* To start with, all buffer is available to user I/O writers */
+	rl->rb_budget = budget;
+	rl->rb_user_max = budget;
+	rl->rb_max_io = budget >> 1;
+	rl->rb_gc_max = 0;
+	rl->rb_state = PBLK_RL_HIGH;
+
+	atomic_set(&rl->rb_user_cnt, 0);
+	atomic_set(&rl->rb_gc_cnt, 0);
+	atomic_set(&rl->rb_space, -1);
+	atomic_set(&rl->werr_lines, 0);
+
+	timer_setup(&rl->u_timer, pblk_rl_u_timer, 0);
+
+	rl->rb_user_active = 0;
+	rl->rb_gc_active = 0;
+}
diff --git a/src/kernel/linux/v4.19/drivers/lightnvm/pblk-sysfs.c b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-sysfs.c
new file mode 100644
index 0000000..bdc86ee
--- /dev/null
+++ b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-sysfs.c
@@ -0,0 +1,720 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@cnexlabs.com>
+ *                  Matias Bjorling <matias@cnexlabs.com>
+ *
+ * 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->all_luns; i++) {
+		int active = 1;
+
+		rlun = &pblk->luns[i];
+		if (!down_trylock(&rlun->wr_sem)) {
+			active = 0;
+			up(&rlun->wr_sem);
+		}
+		sz += snprintf(page + sz, PAGE_SIZE - sz,
+				"pblk: pos:%d, ch:%d, lun:%d - %d\n",
+					i,
+					rlun->bppa.a.ch,
+					rlun->bppa.a.lun,
+					active);
+	}
+
+	return sz;
+}
+
+static ssize_t pblk_sysfs_rate_limiter(struct pblk *pblk, char *page)
+{
+	int free_blocks, free_user_blocks, total_blocks;
+	int rb_user_max, rb_user_cnt;
+	int rb_gc_max, rb_gc_cnt, rb_budget, rb_state;
+
+	free_blocks = pblk_rl_nr_free_blks(&pblk->rl);
+	free_user_blocks = pblk_rl_nr_user_free_blks(&pblk->rl);
+	rb_user_max = pblk->rl.rb_user_max;
+	rb_user_cnt = atomic_read(&pblk->rl.rb_user_cnt);
+	rb_gc_max = pblk->rl.rb_gc_max;
+	rb_gc_cnt = atomic_read(&pblk->rl.rb_gc_cnt);
+	rb_budget = pblk->rl.rb_budget;
+	rb_state = pblk->rl.rb_state;
+
+	total_blocks = pblk->rl.total_blocks;
+
+	return snprintf(page, PAGE_SIZE,
+		"u:%u/%u,gc:%u/%u(%u)(stop:<%u,full:>%u,free:%d/%d/%d)-%d\n",
+				rb_user_cnt,
+				rb_user_max,
+				rb_gc_cnt,
+				rb_gc_max,
+				rb_state,
+				rb_budget,
+				pblk->rl.high,
+				free_blocks,
+				free_user_blocks,
+				total_blocks,
+				READ_ONCE(pblk->rl.rb_user_active));
+}
+
+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 snprintf(page, PAGE_SIZE, "gc_enabled=%d, gc_active=%d\n",
+					gc_enabled, gc_active);
+}
+
+static ssize_t pblk_sysfs_stats(struct pblk *pblk, char *page)
+{
+	ssize_t sz;
+
+	sz = snprintf(page, PAGE_SIZE,
+			"read_failed=%lu, read_high_ecc=%lu, read_empty=%lu, read_failed_gc=%lu, write_failed=%lu, erase_failed=%lu\n",
+			atomic_long_read(&pblk->read_failed),
+			atomic_long_read(&pblk->read_high_ecc),
+			atomic_long_read(&pblk->read_empty),
+			atomic_long_read(&pblk->read_failed_gc),
+			atomic_long_read(&pblk->write_failed),
+			atomic_long_read(&pblk->erase_failed));
+
+	return sz;
+}
+
+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;
+
+	if (geo->version == NVM_OCSSD_SPEC_12) {
+		struct nvm_addrf_12 *ppaf = (struct nvm_addrf_12 *)&pblk->addrf;
+		struct nvm_addrf_12 *gppaf = (struct nvm_addrf_12 *)&geo->addrf;
+
+		sz = snprintf(page, PAGE_SIZE,
+			"g:(b:%d)blk:%d/%d,pg:%d/%d,lun:%d/%d,ch:%d/%d,pl:%d/%d,sec:%d/%d\n",
+			pblk->addrf_len,
+			ppaf->blk_offset, ppaf->blk_len,
+			ppaf->pg_offset, ppaf->pg_len,
+			ppaf->lun_offset, ppaf->lun_len,
+			ppaf->ch_offset, ppaf->ch_len,
+			ppaf->pln_offset, ppaf->pln_len,
+			ppaf->sec_offset, ppaf->sec_len);
+
+		sz += snprintf(page + sz, PAGE_SIZE - sz,
+			"d:blk:%d/%d,pg:%d/%d,lun:%d/%d,ch:%d/%d,pl:%d/%d,sec:%d/%d\n",
+			gppaf->blk_offset, gppaf->blk_len,
+			gppaf->pg_offset, gppaf->pg_len,
+			gppaf->lun_offset, gppaf->lun_len,
+			gppaf->ch_offset, gppaf->ch_len,
+			gppaf->pln_offset, gppaf->pln_len,
+			gppaf->sec_offset, gppaf->sec_len);
+	} else {
+		struct nvm_addrf *ppaf = &pblk->addrf;
+		struct nvm_addrf *gppaf = &geo->addrf;
+
+		sz = snprintf(page, PAGE_SIZE,
+			"pblk:(s:%d)ch:%d/%d,lun:%d/%d,chk:%d/%d/sec:%d/%d\n",
+			pblk->addrf_len,
+			ppaf->ch_offset, ppaf->ch_len,
+			ppaf->lun_offset, ppaf->lun_len,
+			ppaf->chk_offset, ppaf->chk_len,
+			ppaf->sec_offset, ppaf->sec_len);
+
+		sz += snprintf(page + sz, PAGE_SIZE - sz,
+			"device:ch:%d/%d,lun:%d/%d,chk:%d/%d,sec:%d/%d\n",
+			gppaf->ch_offset, gppaf->ch_len,
+			gppaf->lun_offset, gppaf->lun_len,
+			gppaf->chk_offset, gppaf->chk_len,
+			gppaf->sec_offset, gppaf->sec_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, emeta_line_cnt = 0;
+	int d_line_cnt = 0, l_line_cnt = 0;
+	int gc_full = 0, gc_high = 0, gc_mid = 0, gc_low = 0, gc_empty = 0;
+	int gc_werr = 0;
+
+	int bad = 0, cor = 0;
+	int msecs = 0, cur_sec = 0, vsc = 0, sec_in_line = 0;
+	int map_weight = 0, meta_weight = 0;
+
+	spin_lock(&l_mg->free_lock);
+	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->close_lock);
+	list_for_each_entry(line, &l_mg->emeta_list, list)
+		emeta_line_cnt++;
+	spin_unlock(&l_mg->close_lock);
+
+	spin_lock(&l_mg->gc_lock);
+	list_for_each_entry(line, &l_mg->gc_full_list, list) {
+		if (line->type == PBLK_LINETYPE_DATA)
+			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->gc_werr_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_werr++;
+	}
+
+	list_for_each_entry(line, &l_mg->bad_list, list)
+		bad++;
+	list_for_each_entry(line, &l_mg->corrupt_list, list)
+		cor++;
+	spin_unlock(&l_mg->gc_lock);
+
+	spin_lock(&l_mg->free_lock);
+	if (l_mg->data_line) {
+		cur_sec = l_mg->data_line->cur_sec;
+		msecs = l_mg->data_line->left_msecs;
+		vsc = le32_to_cpu(*l_mg->data_line->vsc);
+		sec_in_line = l_mg->data_line->sec_in_line;
+		meta_weight = bitmap_weight(&l_mg->meta_bitmap,
+							PBLK_DATA_LINES);
+
+		spin_lock(&l_mg->data_line->lock);
+		if (l_mg->data_line->map_bitmap)
+			map_weight = bitmap_weight(l_mg->data_line->map_bitmap,
+							lm->sec_per_line);
+		else
+			map_weight = 0;
+		spin_unlock(&l_mg->data_line->lock);
+	}
+	spin_unlock(&l_mg->free_lock);
+
+	if (nr_free_lines != free_line_cnt)
+		pblk_err(pblk, "corrupted free line list:%d/%d\n",
+						nr_free_lines, free_line_cnt);
+
+	sz = snprintf(page, PAGE_SIZE - sz,
+		"line: nluns:%d, nblks:%d, nsecs:%d\n",
+		geo->all_luns, lm->blk_per_line, lm->sec_per_line);
+
+	sz += snprintf(page + sz, PAGE_SIZE - sz,
+		"lines:d:%d,l:%d-f:%d,m:%d/%d,c:%d,b:%d,co:%d(d:%d,l:%d)t:%d\n",
+					cur_data, cur_log,
+					nr_free_lines,
+					emeta_line_cnt, meta_weight,
+					closed_line_cnt,
+					bad, cor,
+					d_line_cnt, l_line_cnt,
+					l_mg->nr_lines);
+
+	sz += snprintf(page + sz, PAGE_SIZE - sz,
+		"GC: full:%d, high:%d, mid:%d, low:%d, empty:%d, werr: %d, queue:%d\n",
+			gc_full, gc_high, gc_mid, gc_low, gc_empty, gc_werr,
+			atomic_read(&pblk->gc.read_inflight_gc));
+
+	sz += snprintf(page + sz, PAGE_SIZE - sz,
+		"data (%d) cur:%d, left:%d, vsc:%d, s:%d, map:%d/%d (%d)\n",
+			cur_data, cur_sec, msecs, vsc, sec_in_line,
+			map_weight, lm->sec_per_line,
+			atomic_read(&pblk->inflight_io));
+
+	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 = snprintf(page, PAGE_SIZE - sz,
+				"smeta - len:%d, secs:%d\n",
+					lm->smeta_len, lm->smeta_sec);
+	sz += snprintf(page + sz, PAGE_SIZE - sz,
+				"emeta - len:%d, sec:%d, bb_start:%d\n",
+					lm->emeta_len[0], lm->emeta_sec[0],
+					lm->emeta_bb);
+	sz += snprintf(page + sz, PAGE_SIZE - sz,
+				"bitmap lengths: sec:%d, blk:%d, lun:%d\n",
+					lm->sec_bitmap_len,
+					lm->blk_bitmap_len,
+					lm->lun_bitmap_len);
+	sz += snprintf(page + sz, PAGE_SIZE - sz,
+				"blk_line:%d, sec_line:%d, sec_blk:%d\n",
+					lm->blk_per_line,
+					lm->sec_per_line,
+					geo->clba);
+
+	return sz;
+}
+
+static ssize_t pblk_sysfs_get_sec_per_write(struct pblk *pblk, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%d\n", pblk->sec_per_write);
+}
+
+static ssize_t pblk_get_write_amp(u64 user, u64 gc, u64 pad,
+				  char *page)
+{
+	int sz;
+
+	sz = snprintf(page, PAGE_SIZE,
+			"user:%lld gc:%lld pad:%lld WA:",
+			user, gc, pad);
+
+	if (!user) {
+		sz += snprintf(page + sz, PAGE_SIZE - sz, "NaN\n");
+	} else {
+		u64 wa_int;
+		u32 wa_frac;
+
+		wa_int = (user + gc + pad) * 100000;
+		wa_int = div64_u64(wa_int, user);
+		wa_int = div_u64_rem(wa_int, 100000, &wa_frac);
+
+		sz += snprintf(page + sz, PAGE_SIZE - sz, "%llu.%05u\n",
+							wa_int, wa_frac);
+	}
+
+	return sz;
+}
+
+static ssize_t pblk_sysfs_get_write_amp_mileage(struct pblk *pblk, char *page)
+{
+	return pblk_get_write_amp(atomic64_read(&pblk->user_wa),
+		atomic64_read(&pblk->gc_wa), atomic64_read(&pblk->pad_wa),
+		page);
+}
+
+static ssize_t pblk_sysfs_get_write_amp_trip(struct pblk *pblk, char *page)
+{
+	return pblk_get_write_amp(
+		atomic64_read(&pblk->user_wa) - pblk->user_rst_wa,
+		atomic64_read(&pblk->gc_wa) - pblk->gc_rst_wa,
+		atomic64_read(&pblk->pad_wa) - pblk->pad_rst_wa, page);
+}
+
+static long long bucket_percentage(unsigned long long bucket,
+				   unsigned long long total)
+{
+	int p = bucket * 100;
+
+	p = div_u64(p, total);
+
+	return p;
+}
+
+static ssize_t pblk_sysfs_get_padding_dist(struct pblk *pblk, char *page)
+{
+	int sz = 0;
+	unsigned long long total;
+	unsigned long long total_buckets = 0;
+	int buckets = pblk->min_write_pgs - 1;
+	int i;
+
+	total = atomic64_read(&pblk->nr_flush) - pblk->nr_flush_rst;
+	if (!total) {
+		for (i = 0; i < (buckets + 1); i++)
+			sz += snprintf(page + sz, PAGE_SIZE - sz,
+				"%d:0 ", i);
+		sz += snprintf(page + sz, PAGE_SIZE - sz, "\n");
+
+		return sz;
+	}
+
+	for (i = 0; i < buckets; i++)
+		total_buckets += atomic64_read(&pblk->pad_dist[i]);
+
+	sz += snprintf(page + sz, PAGE_SIZE - sz, "0:%lld%% ",
+		bucket_percentage(total - total_buckets, total));
+
+	for (i = 0; i < buckets; i++) {
+		unsigned long long p;
+
+		p = bucket_percentage(atomic64_read(&pblk->pad_dist[i]),
+					  total);
+		sz += snprintf(page + sz, PAGE_SIZE - sz, "%d:%lld%% ",
+				i + 1, p);
+	}
+	sz += snprintf(page + sz, PAGE_SIZE - sz, "\n");
+
+	return sz;
+}
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+static ssize_t pblk_sysfs_stats_debug(struct pblk *pblk, char *page)
+{
+	return snprintf(page, PAGE_SIZE,
+		"%lu\t%lu\t%ld\t%llu\t%ld\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\n",
+			atomic_long_read(&pblk->inflight_writes),
+			atomic_long_read(&pblk->inflight_reads),
+			atomic_long_read(&pblk->req_writes),
+			(u64)atomic64_read(&pblk->nr_flush),
+			atomic_long_read(&pblk->padded_writes),
+			atomic_long_read(&pblk->padded_wb),
+			atomic_long_read(&pblk->sub_writes),
+			atomic_long_read(&pblk->sync_writes),
+			atomic_long_read(&pblk->recov_writes),
+			atomic_long_read(&pblk->recov_gc_writes),
+			atomic_long_read(&pblk->recov_gc_reads),
+			atomic_long_read(&pblk->cache_reads),
+			atomic_long_read(&pblk->sync_reads));
+}
+#endif
+
+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;
+
+	pblk_gc_sysfs_force(pblk, force);
+
+	return len;
+}
+
+static ssize_t pblk_sysfs_set_sec_per_write(struct pblk *pblk,
+					     const char *page, size_t len)
+{
+	size_t c_len;
+	int sec_per_write;
+
+	c_len = strcspn(page, "\n");
+	if (c_len >= len)
+		return -EINVAL;
+
+	if (kstrtouint(page, 0, &sec_per_write))
+		return -EINVAL;
+
+	if (sec_per_write < pblk->min_write_pgs
+				|| sec_per_write > pblk->max_write_pgs
+				|| sec_per_write % pblk->min_write_pgs != 0)
+		return -EINVAL;
+
+	pblk_set_sec_per_write(pblk, sec_per_write);
+
+	return len;
+}
+
+static ssize_t pblk_sysfs_set_write_amp_trip(struct pblk *pblk,
+			const char *page, size_t len)
+{
+	size_t c_len;
+	int reset_value;
+
+	c_len = strcspn(page, "\n");
+	if (c_len >= len)
+		return -EINVAL;
+
+	if (kstrtouint(page, 0, &reset_value))
+		return -EINVAL;
+
+	if (reset_value !=  0)
+		return -EINVAL;
+
+	pblk->user_rst_wa = atomic64_read(&pblk->user_wa);
+	pblk->pad_rst_wa = atomic64_read(&pblk->pad_wa);
+	pblk->gc_rst_wa = atomic64_read(&pblk->gc_wa);
+
+	return len;
+}
+
+
+static ssize_t pblk_sysfs_set_padding_dist(struct pblk *pblk,
+			const char *page, size_t len)
+{
+	size_t c_len;
+	int reset_value;
+	int buckets = pblk->min_write_pgs - 1;
+	int i;
+
+	c_len = strcspn(page, "\n");
+	if (c_len >= len)
+		return -EINVAL;
+
+	if (kstrtouint(page, 0, &reset_value))
+		return -EINVAL;
+
+	if (reset_value !=  0)
+		return -EINVAL;
+
+	for (i = 0; i < buckets; i++)
+		atomic64_set(&pblk->pad_dist[i], 0);
+
+	pblk->nr_flush_rst = atomic64_read(&pblk->nr_flush);
+
+	return len;
+}
+
+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_max_sec_per_write = {
+	.name = "max_sec_per_write",
+	.mode = 0644,
+};
+
+static struct attribute sys_write_amp_mileage = {
+	.name = "write_amp_mileage",
+	.mode = 0444,
+};
+
+static struct attribute sys_write_amp_trip = {
+	.name = "write_amp_trip",
+	.mode = 0644,
+};
+
+static struct attribute sys_padding_dist = {
+	.name = "padding_dist",
+	.mode = 0644,
+};
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+static struct attribute sys_stats_debug_attr = {
+	.name = "stats",
+	.mode = 0444,
+};
+#endif
+
+static struct attribute *pblk_attrs[] = {
+	&sys_write_luns,
+	&sys_rate_limiter_attr,
+	&sys_errors_attr,
+	&sys_gc_state,
+	&sys_gc_force,
+	&sys_max_sec_per_write,
+	&sys_rb_attr,
+	&sys_stats_ppaf_attr,
+	&sys_lines_attr,
+	&sys_lines_info_attr,
+	&sys_write_amp_mileage,
+	&sys_write_amp_trip,
+	&sys_padding_dist,
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	&sys_stats_debug_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);
+	else if (strcmp(attr->name, "max_sec_per_write") == 0)
+		return pblk_sysfs_get_sec_per_write(pblk, buf);
+	else if (strcmp(attr->name, "write_amp_mileage") == 0)
+		return pblk_sysfs_get_write_amp_mileage(pblk, buf);
+	else if (strcmp(attr->name, "write_amp_trip") == 0)
+		return pblk_sysfs_get_write_amp_trip(pblk, buf);
+	else if (strcmp(attr->name, "padding_dist") == 0)
+		return pblk_sysfs_get_padding_dist(pblk, buf);
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	else if (strcmp(attr->name, "stats") == 0)
+		return pblk_sysfs_stats_debug(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_force") == 0)
+		return pblk_sysfs_gc_force(pblk, buf, len);
+	else if (strcmp(attr->name, "max_sec_per_write") == 0)
+		return pblk_sysfs_set_sec_per_write(pblk, buf, len);
+	else if (strcmp(attr->name, "write_amp_trip") == 0)
+		return pblk_sysfs_set_write_amp_trip(pblk, buf, len);
+	else if (strcmp(attr->name, "padding_dist") == 0)
+		return pblk_sysfs_set_padding_dist(pblk, buf, len);
+	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) {
+		pblk_err(pblk, "could not register\n");
+		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/src/kernel/linux/v4.19/drivers/lightnvm/pblk-write.c b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-write.c
new file mode 100644
index 0000000..c3e038d
--- /dev/null
+++ b/src/kernel/linux/v4.19/drivers/lightnvm/pblk-write.c
@@ -0,0 +1,673 @@
+/*
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Javier Gonzalez <javier@cnexlabs.com>
+ *                  Matias Bjorling <matias@cnexlabs.com>
+ *
+ * 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 unsigned long pblk_end_w_bio(struct pblk *pblk, struct nvm_rq *rqd,
+				    struct pblk_c_ctx *c_ctx)
+{
+	struct bio *original_bio;
+	struct pblk_rb *rwb = &pblk->rwb;
+	unsigned long ret;
+	int i;
+
+	for (i = 0; i < c_ctx->nr_valid; i++) {
+		struct pblk_w_ctx *w_ctx;
+		int pos = c_ctx->sentry + i;
+		int flags;
+
+		w_ctx = pblk_rb_w_ctx(rwb, pos);
+		flags = READ_ONCE(w_ctx->flags);
+
+		if (flags & PBLK_FLUSH_ENTRY) {
+			flags &= ~PBLK_FLUSH_ENTRY;
+			/* Release flags on context. Protect from writes */
+			smp_store_release(&w_ctx->flags, flags);
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+			atomic_dec(&rwb->inflight_flush_point);
+#endif
+		}
+
+		while ((original_bio = bio_list_pop(&w_ctx->bios)))
+			bio_endio(original_bio);
+	}
+
+	if (c_ctx->nr_padded)
+		pblk_bio_free_pages(pblk, rqd->bio, c_ctx->nr_valid,
+							c_ctx->nr_padded);
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	atomic_long_add(rqd->nr_ppas, &pblk->sync_writes);
+#endif
+
+	ret = pblk_rb_sync_advance(&pblk->rwb, c_ctx->nr_valid);
+
+	bio_put(rqd->bio);
+	pblk_free_rqd(pblk, rqd, PBLK_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_PBLK_DEBUG
+	atomic_long_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);
+}
+
+/* Map remaining sectors in chunk, starting from ppa */
+static void pblk_map_remaining(struct pblk *pblk, struct ppa_addr *ppa)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_line *line;
+	struct ppa_addr map_ppa = *ppa;
+	u64 paddr;
+	int done = 0;
+
+	line = &pblk->lines[pblk_ppa_to_line(*ppa)];
+	spin_lock(&line->lock);
+
+	while (!done)  {
+		paddr = pblk_dev_ppa_to_line_addr(pblk, map_ppa);
+
+		if (!test_and_set_bit(paddr, line->map_bitmap))
+			line->left_msecs--;
+
+		if (!test_and_set_bit(paddr, line->invalid_bitmap))
+			le32_add_cpu(line->vsc, -1);
+
+		if (geo->version == NVM_OCSSD_SPEC_12) {
+			map_ppa.ppa++;
+			if (map_ppa.g.pg == geo->num_pg)
+				done = 1;
+		} else {
+			map_ppa.m.sec++;
+			if (map_ppa.m.sec == geo->clba)
+				done = 1;
+		}
+	}
+
+	line->w_err_gc->has_write_err = 1;
+	spin_unlock(&line->lock);
+}
+
+static void pblk_prepare_resubmit(struct pblk *pblk, unsigned int sentry,
+				  unsigned int nr_entries)
+{
+	struct pblk_rb *rb = &pblk->rwb;
+	struct pblk_rb_entry *entry;
+	struct pblk_line *line;
+	struct pblk_w_ctx *w_ctx;
+	struct ppa_addr ppa_l2p;
+	int flags;
+	unsigned int pos, i;
+
+	spin_lock(&pblk->trans_lock);
+	pos = sentry;
+	for (i = 0; i < nr_entries; i++) {
+		entry = &rb->entries[pos];
+		w_ctx = &entry->w_ctx;
+
+		/* Check if the lba has been overwritten */
+		if (w_ctx->lba != ADDR_EMPTY) {
+			ppa_l2p = pblk_trans_map_get(pblk, w_ctx->lba);
+			if (!pblk_ppa_comp(ppa_l2p, entry->cacheline))
+				w_ctx->lba = ADDR_EMPTY;
+		}
+
+		/* Mark up the entry as submittable again */
+		flags = READ_ONCE(w_ctx->flags);
+		flags |= PBLK_WRITTEN_DATA;
+		/* Release flags on write context. Protect from writes */
+		smp_store_release(&w_ctx->flags, flags);
+
+		/* Decrese the reference count to the line as we will
+		 * re-map these entries
+		 */
+		line = &pblk->lines[pblk_ppa_to_line(w_ctx->ppa)];
+		kref_put(&line->ref, pblk_line_put);
+
+		pos = (pos + 1) & (rb->nr_entries - 1);
+	}
+	spin_unlock(&pblk->trans_lock);
+}
+
+static void pblk_queue_resubmit(struct pblk *pblk, struct pblk_c_ctx *c_ctx)
+{
+	struct pblk_c_ctx *r_ctx;
+
+	r_ctx = kzalloc(sizeof(struct pblk_c_ctx), GFP_KERNEL);
+	if (!r_ctx)
+		return;
+
+	r_ctx->lun_bitmap = NULL;
+	r_ctx->sentry = c_ctx->sentry;
+	r_ctx->nr_valid = c_ctx->nr_valid;
+	r_ctx->nr_padded = c_ctx->nr_padded;
+
+	spin_lock(&pblk->resubmit_lock);
+	list_add_tail(&r_ctx->list, &pblk->resubmit_list);
+	spin_unlock(&pblk->resubmit_lock);
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	atomic_long_add(c_ctx->nr_valid, &pblk->recov_writes);
+#endif
+}
+
+static 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_rq *rqd = recovery->rqd;
+	struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
+	struct ppa_addr *ppa_list;
+
+	pblk_log_write_err(pblk, rqd);
+
+	if (rqd->nr_ppas == 1)
+		ppa_list = &rqd->ppa_addr;
+	else
+		ppa_list = rqd->ppa_list;
+
+	pblk_map_remaining(pblk, ppa_list);
+	pblk_queue_resubmit(pblk, c_ctx);
+
+	pblk_up_rq(pblk, rqd->ppa_list, rqd->nr_ppas, c_ctx->lun_bitmap);
+	if (c_ctx->nr_padded)
+		pblk_bio_free_pages(pblk, rqd->bio, c_ctx->nr_valid,
+							c_ctx->nr_padded);
+	bio_put(rqd->bio);
+	pblk_free_rqd(pblk, rqd, PBLK_WRITE);
+	mempool_free(recovery, &pblk->rec_pool);
+
+	atomic_dec(&pblk->inflight_io);
+}
+
+
+static void pblk_end_w_fail(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	struct pblk_rec_ctx *recovery;
+
+	recovery = mempool_alloc(&pblk->rec_pool, GFP_ATOMIC);
+	if (!recovery) {
+		pblk_err(pblk, "could not allocate recovery work\n");
+		return;
+	}
+
+	recovery->pblk = pblk;
+	recovery->rqd = rqd;
+
+	INIT_WORK(&recovery->ws_rec, pblk_submit_rec);
+	queue_work(pblk->close_wq, &recovery->ws_rec);
+}
+
+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_end_w_fail(pblk, rqd);
+		return;
+	}
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	else
+		WARN_ONCE(rqd->bio->bi_status, "pblk: corrupted write error\n");
+#endif
+
+	pblk_complete_write(pblk, rqd, c_ctx);
+	atomic_dec(&pblk->inflight_io);
+}
+
+static void pblk_end_io_write_meta(struct nvm_rq *rqd)
+{
+	struct pblk *pblk = rqd->private;
+	struct pblk_g_ctx *m_ctx = nvm_rq_to_pdu(rqd);
+	struct pblk_line *line = m_ctx->private;
+	struct pblk_emeta *emeta = line->emeta;
+	int sync;
+
+	pblk_up_page(pblk, rqd->ppa_list, rqd->nr_ppas);
+
+	if (rqd->error) {
+		pblk_log_write_err(pblk, rqd);
+		pblk_err(pblk, "metadata I/O failed. Line %d\n", line->id);
+		line->w_err_gc->has_write_err = 1;
+	}
+
+	sync = atomic_add_return(rqd->nr_ppas, &emeta->sync);
+	if (sync == emeta->nr_entries)
+		pblk_gen_run_ws(pblk, line, NULL, pblk_line_close_ws,
+						GFP_ATOMIC, pblk->close_wq);
+
+	pblk_free_rqd(pblk, rqd, PBLK_WRITE_INT);
+
+	atomic_dec(&pblk->inflight_io);
+}
+
+static int pblk_alloc_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
+			   unsigned int nr_secs,
+			   nvm_end_io_fn(*end_io))
+{
+	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, PBLK_WRITE);
+	rqd->private = pblk;
+	rqd->end_io = end_io;
+
+	rqd->meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
+							&rqd->dma_meta_list);
+	if (!rqd->meta_list)
+		return -ENOMEM;
+
+	rqd->ppa_list = rqd->meta_list + pblk_dma_meta_size;
+	rqd->dma_ppa_list = rqd->dma_meta_list + pblk_dma_meta_size;
+
+	return 0;
+}
+
+static int pblk_setup_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
+			   struct ppa_addr *erase_ppa)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_line *e_line = pblk_line_get_erase(pblk);
+	struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
+	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;
+
+	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, nr_secs, pblk_end_io_write);
+	if (ret) {
+		kfree(lun_bitmap);
+		return ret;
+	}
+
+	if (likely(!e_line || !atomic_read(&e_line->left_eblks)))
+		pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, valid, 0);
+	else
+		pblk_map_erase_rq(pblk, rqd, c_ctx->sentry, lun_bitmap,
+							valid, erase_ppa);
+
+	return 0;
+}
+
+static int pblk_calc_secs_to_sync(struct pblk *pblk, unsigned int secs_avail,
+				  unsigned int secs_to_flush)
+{
+	int secs_to_sync;
+
+	secs_to_sync = pblk_calc_secs(pblk, secs_avail, secs_to_flush);
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	if ((!secs_to_sync && secs_to_flush)
+			|| (secs_to_sync < 0)
+			|| (secs_to_sync > secs_avail && !secs_to_flush)) {
+		pblk_err(pblk, "bad sector calculation (a:%d,s:%d,f:%d)\n",
+				secs_avail, secs_to_sync, secs_to_flush);
+	}
+#endif
+
+	return secs_to_sync;
+}
+
+int pblk_submit_meta_io(struct pblk *pblk, struct pblk_line *meta_line)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_emeta *emeta = meta_line->emeta;
+	struct pblk_g_ctx *m_ctx;
+	struct bio *bio;
+	struct nvm_rq *rqd;
+	void *data;
+	u64 paddr;
+	int rq_ppas = pblk->min_write_pgs;
+	int id = meta_line->id;
+	int rq_len;
+	int i, j;
+	int ret;
+
+	rqd = pblk_alloc_rqd(pblk, PBLK_WRITE_INT);
+
+	m_ctx = nvm_rq_to_pdu(rqd);
+	m_ctx->private = meta_line;
+
+	rq_len = rq_ppas * geo->csecs;
+	data = ((void *)emeta->buf) + emeta->mem;
+
+	bio = pblk_bio_map_addr(pblk, data, rq_ppas, rq_len,
+					l_mg->emeta_alloc_type, GFP_KERNEL);
+	if (IS_ERR(bio)) {
+		pblk_err(pblk, "failed to map emeta io");
+		ret = PTR_ERR(bio);
+		goto fail_free_rqd;
+	}
+	bio->bi_iter.bi_sector = 0; /* internal bio */
+	bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+	rqd->bio = bio;
+
+	ret = pblk_alloc_w_rq(pblk, rqd, rq_ppas, pblk_end_io_write_meta);
+	if (ret)
+		goto fail_free_bio;
+
+	for (i = 0; i < rqd->nr_ppas; ) {
+		spin_lock(&meta_line->lock);
+		paddr = __pblk_alloc_page(pblk, meta_line, rq_ppas);
+		spin_unlock(&meta_line->lock);
+		for (j = 0; j < rq_ppas; j++, i++, paddr++)
+			rqd->ppa_list[i] = addr_to_gen_ppa(pblk, paddr, id);
+	}
+
+	spin_lock(&l_mg->close_lock);
+	emeta->mem += rq_len;
+	if (emeta->mem >= lm->emeta_len[0])
+		list_del(&meta_line->list);
+	spin_unlock(&l_mg->close_lock);
+
+	pblk_down_page(pblk, rqd->ppa_list, rqd->nr_ppas);
+
+	ret = pblk_submit_io(pblk, rqd);
+	if (ret) {
+		pblk_err(pblk, "emeta I/O submission failed: %d\n", ret);
+		goto fail_rollback;
+	}
+
+	return NVM_IO_OK;
+
+fail_rollback:
+	pblk_up_page(pblk, rqd->ppa_list, rqd->nr_ppas);
+	spin_lock(&l_mg->close_lock);
+	pblk_dealloc_page(pblk, meta_line, rq_ppas);
+	list_add(&meta_line->list, &meta_line->list);
+	spin_unlock(&l_mg->close_lock);
+fail_free_bio:
+	bio_put(bio);
+fail_free_rqd:
+	pblk_free_rqd(pblk, rqd, PBLK_WRITE_INT);
+	return ret;
+}
+
+static inline bool pblk_valid_meta_ppa(struct pblk *pblk,
+				       struct pblk_line *meta_line,
+				       struct nvm_rq *data_rqd)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct pblk_c_ctx *data_c_ctx = nvm_rq_to_pdu(data_rqd);
+	struct pblk_line *data_line = pblk_line_get_data(pblk);
+	struct ppa_addr ppa, ppa_opt;
+	u64 paddr;
+	int pos_opt;
+
+	/* Schedule a metadata I/O that is half the distance from the data I/O
+	 * with regards to the number of LUNs forming the pblk instance. This
+	 * balances LUN conflicts across every I/O.
+	 *
+	 * When the LUN configuration changes (e.g., due to GC), this distance
+	 * can align, which would result on metadata and data I/Os colliding. In
+	 * this case, modify the distance to not be optimal, but move the
+	 * optimal in the right direction.
+	 */
+	paddr = pblk_lookup_page(pblk, meta_line);
+	ppa = addr_to_gen_ppa(pblk, paddr, 0);
+	ppa_opt = addr_to_gen_ppa(pblk, paddr + data_line->meta_distance, 0);
+	pos_opt = pblk_ppa_to_pos(geo, ppa_opt);
+
+	if (test_bit(pos_opt, data_c_ctx->lun_bitmap) ||
+				test_bit(pos_opt, data_line->blk_bitmap))
+		return true;
+
+	if (unlikely(pblk_ppa_comp(ppa_opt, ppa)))
+		data_line->meta_distance--;
+
+	return false;
+}
+
+static struct pblk_line *pblk_should_submit_meta_io(struct pblk *pblk,
+						    struct nvm_rq *data_rqd)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
+	struct pblk_line *meta_line;
+
+	spin_lock(&l_mg->close_lock);
+	if (list_empty(&l_mg->emeta_list)) {
+		spin_unlock(&l_mg->close_lock);
+		return NULL;
+	}
+	meta_line = list_first_entry(&l_mg->emeta_list, struct pblk_line, list);
+	if (meta_line->emeta->mem >= lm->emeta_len[0]) {
+		spin_unlock(&l_mg->close_lock);
+		return NULL;
+	}
+	spin_unlock(&l_mg->close_lock);
+
+	if (!pblk_valid_meta_ppa(pblk, meta_line, data_rqd))
+		return NULL;
+
+	return meta_line;
+}
+
+static int pblk_submit_io_set(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	struct ppa_addr erase_ppa;
+	struct pblk_line *meta_line;
+	int err;
+
+	pblk_ppa_set_empty(&erase_ppa);
+
+	/* Assign lbas to ppas and populate request structure */
+	err = pblk_setup_w_rq(pblk, rqd, &erase_ppa);
+	if (err) {
+		pblk_err(pblk, "could not setup write request: %d\n", err);
+		return NVM_IO_ERR;
+	}
+
+	meta_line = pblk_should_submit_meta_io(pblk, rqd);
+
+	/* Submit data write for current data line */
+	err = pblk_submit_io(pblk, rqd);
+	if (err) {
+		pblk_err(pblk, "data I/O submission failed: %d\n", err);
+		return NVM_IO_ERR;
+	}
+
+	if (!pblk_ppa_empty(erase_ppa)) {
+		/* Submit erase for next data line */
+		if (pblk_blk_erase_async(pblk, erase_ppa)) {
+			struct pblk_line *e_line = pblk_line_get_erase(pblk);
+			struct nvm_tgt_dev *dev = pblk->dev;
+			struct nvm_geo *geo = &dev->geo;
+			int bit;
+
+			atomic_inc(&e_line->left_eblks);
+			bit = pblk_ppa_to_pos(geo, erase_ppa);
+			WARN_ON(!test_and_clear_bit(bit, e_line->erase_bitmap));
+		}
+	}
+
+	if (meta_line) {
+		/* Submit metadata write for previous data line */
+		err = pblk_submit_meta_io(pblk, meta_line);
+		if (err) {
+			pblk_err(pblk, "metadata I/O submission failed: %d",
+					err);
+			return NVM_IO_ERR;
+		}
+	}
+
+	return NVM_IO_OK;
+}
+
+static void pblk_free_write_rqd(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
+	struct bio *bio = rqd->bio;
+
+	if (c_ctx->nr_padded)
+		pblk_bio_free_pages(pblk, bio, c_ctx->nr_valid,
+							c_ctx->nr_padded);
+}
+
+static int pblk_submit_write(struct pblk *pblk)
+{
+	struct bio *bio;
+	struct nvm_rq *rqd;
+	unsigned int secs_avail, secs_to_sync, secs_to_com;
+	unsigned int secs_to_flush;
+	unsigned long pos;
+	unsigned int resubmit;
+
+	spin_lock(&pblk->resubmit_lock);
+	resubmit = !list_empty(&pblk->resubmit_list);
+	spin_unlock(&pblk->resubmit_lock);
+
+	/* Resubmit failed writes first */
+	if (resubmit) {
+		struct pblk_c_ctx *r_ctx;
+
+		spin_lock(&pblk->resubmit_lock);
+		r_ctx = list_first_entry(&pblk->resubmit_list,
+					struct pblk_c_ctx, list);
+		list_del(&r_ctx->list);
+		spin_unlock(&pblk->resubmit_lock);
+
+		secs_avail = r_ctx->nr_valid;
+		pos = r_ctx->sentry;
+
+		pblk_prepare_resubmit(pblk, pos, secs_avail);
+		secs_to_sync = pblk_calc_secs_to_sync(pblk, secs_avail,
+				secs_avail);
+
+		kfree(r_ctx);
+	} else {
+		/* 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_flush_point_count(&pblk->rwb);
+		if (!secs_to_flush && secs_avail < pblk->min_write_pgs)
+			return 1;
+
+		secs_to_sync = pblk_calc_secs_to_sync(pblk, secs_avail,
+					secs_to_flush);
+		if (secs_to_sync > pblk->max_write_pgs) {
+			pblk_err(pblk, "bad buffer sync calculation\n");
+			return 1;
+		}
+
+		secs_to_com = (secs_to_sync > secs_avail) ?
+			secs_avail : secs_to_sync;
+		pos = pblk_rb_read_commit(&pblk->rwb, secs_to_com);
+	}
+
+	bio = bio_alloc(GFP_KERNEL, secs_to_sync);
+
+	bio->bi_iter.bi_sector = 0; /* internal bio */
+	bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+
+	rqd = pblk_alloc_rqd(pblk, PBLK_WRITE);
+	rqd->bio = bio;
+
+	if (pblk_rb_read_to_bio(&pblk->rwb, rqd, pos, secs_to_sync,
+								secs_avail)) {
+		pblk_err(pblk, "corrupted write bio\n");
+		goto fail_put_bio;
+	}
+
+	if (pblk_submit_io_set(pblk, rqd))
+		goto fail_free_bio;
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	atomic_long_add(secs_to_sync, &pblk->sub_writes);
+#endif
+
+	return 0;
+
+fail_free_bio:
+	pblk_free_write_rqd(pblk, rqd);
+fail_put_bio:
+	bio_put(bio);
+	pblk_free_rqd(pblk, rqd, PBLK_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/src/kernel/linux/v4.19/drivers/lightnvm/pblk.h b/src/kernel/linux/v4.19/drivers/lightnvm/pblk.h
new file mode 100644
index 0000000..4760af7
--- /dev/null
+++ b/src/kernel/linux/v4.19/drivers/lightnvm/pblk.h
@@ -0,0 +1,1444 @@
+/*
+ * Copyright (C) 2015 IT University of Copenhagen (rrpc.h)
+ * Copyright (C) 2016 CNEX Labs
+ * Initial release: Matias Bjorling <matias@cnexlabs.com>
+ * Write buffering: Javier Gonzalez <javier@cnexlabs.com>
+ *
+ * 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.
+ *
+ */
+
+#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/uuid.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)
+
+#define PBLK_NR_CLOSE_JOBS (4)
+
+#define PBLK_CACHE_NAME_LEN (DISK_NAME_LEN + 16)
+
+#define PBLK_COMMAND_TIMEOUT_MS 30000
+
+/* Max 512 LUNs per device */
+#define PBLK_MAX_LUNS_BITMAP (4)
+
+#define NR_PHY_IN_LOG (PBLK_EXPOSED_PAGE_SIZE / PBLK_SECTOR)
+
+/* Static pool sizes */
+#define PBLK_GEN_WS_POOL_SIZE (2)
+
+#define PBLK_DEFAULT_OP (11)
+
+enum {
+	PBLK_READ		= READ,
+	PBLK_WRITE		= WRITE,/* Write from write buffer */
+	PBLK_WRITE_INT,			/* Internal write - no write buffer */
+	PBLK_READ_RECOV,		/* Recovery read - errors allowed */
+	PBLK_ERASE,
+};
+
+enum {
+	/* IO Types */
+	PBLK_IOTYPE_USER	= 1 << 0,
+	PBLK_IOTYPE_GC		= 1 << 1,
+
+	/* Write buffer flags */
+	PBLK_FLUSH_ENTRY	= 1 << 2,
+	PBLK_WRITTEN_DATA	= 1 << 3,
+	PBLK_SUBMITTED_ENTRY	= 1 << 4,
+	PBLK_WRITABLE_ENTRY	= 1 << 5,
+};
+
+enum {
+	PBLK_BLK_ST_OPEN =	0x1,
+	PBLK_BLK_ST_CLOSED =	0x2,
+};
+
+struct pblk_sec_meta {
+	u64 reserved;
+	__le64 lba;
+};
+
+/* The number of GC lists and the rate-limiter states go together. This way the
+ * rate-limiter can dictate how much GC is needed based on resource utilization.
+ */
+#define PBLK_GC_NR_LISTS 4
+
+enum {
+	PBLK_RL_OFF = 0,
+	PBLK_RL_WERR = 1,
+	PBLK_RL_HIGH = 2,
+	PBLK_RL_MID = 3,
+	PBLK_RL_LOW = 4
+};
+
+#define pblk_dma_meta_size (sizeof(struct pblk_sec_meta) * PBLK_MAX_REQ_ADDRS)
+#define pblk_dma_ppa_size (sizeof(u64) * PBLK_MAX_REQ_ADDRS)
+
+/* write buffer 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_g_ctx {
+	void *private;
+	unsigned long start_time;
+	u64 lba;
+};
+
+/* partial read context */
+struct pblk_pr_ctx {
+	struct bio *orig_bio;
+	DECLARE_BITMAP(bitmap, NVM_MAX_VLBA);
+	unsigned int orig_nr_secs;
+	unsigned int bio_init_idx;
+	void *ppa_ptr;
+	dma_addr_t dma_ppa_list;
+};
+
+/* Pad context */
+struct pblk_pad_rq {
+	struct pblk *pblk;
+	struct completion wait;
+	struct kref ref;
+};
+
+/* Recovery context */
+struct pblk_rec_ctx {
+	struct pblk *pblk;
+	struct nvm_rq *rqd;
+	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
+					 */
+	u64 lba;			/* Logic addr. associated with entry */
+	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 flush_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_PBLK_DEBUG
+	atomic_t inflight_flush_point;	/* Not served REQ_FLUSH | REQ_FUA */
+#endif
+};
+
+#define PBLK_RECOVERY_SECTORS 16
+
+struct pblk_lun {
+	struct ppa_addr bppa;
+	struct semaphore wr_sem;
+};
+
+struct pblk_gc_rq {
+	struct pblk_line *line;
+	void *data;
+	u64 paddr_list[PBLK_MAX_REQ_ADDRS];
+	u64 lba_list[PBLK_MAX_REQ_ADDRS];
+	int nr_secs;
+	int secs_to_gc;
+	struct list_head list;
+};
+
+struct pblk_gc {
+	/* These states are not protected by a lock since (i) they are in the
+	 * fast path, and (ii) they are not critical.
+	 */
+	int gc_active;
+	int gc_enabled;
+	int gc_forced;
+
+	struct task_struct *gc_ts;
+	struct task_struct *gc_writer_ts;
+	struct task_struct *gc_reader_ts;
+
+	struct workqueue_struct *gc_line_reader_wq;
+	struct workqueue_struct *gc_reader_wq;
+
+	struct timer_list gc_timer;
+
+	struct semaphore gc_sem;
+	atomic_t read_inflight_gc; /* Number of lines with inflight GC reads */
+	atomic_t pipeline_gc;	   /* Number of lines in the GC pipeline -
+				    * started reads to finished writes
+				    */
+	int w_entries;
+
+	struct list_head w_list;
+	struct list_head r_list;
+
+	spinlock_t lock;
+	spinlock_t w_lock;
+	spinlock_t r_lock;
+};
+
+struct pblk_rl {
+	unsigned int high;	/* Upper threshold for rate limiter (free run -
+				 * user I/O rate limiter
+				 */
+	unsigned int high_pw;	/* High rounded up as a power of 2 */
+
+#define PBLK_USER_HIGH_THRS 8	/* Begin write limit at 12% available blks */
+#define PBLK_USER_LOW_THRS 10	/* Aggressive GC at 10% available blocks */
+
+	int rb_windows_pw;	/* Number of rate windows in the write buffer
+				 * given as a power-of-2. This guarantees that
+				 * 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_gc_max;		/* Max buffer entries available for GC I/O */
+	int rb_gc_rsv;		/* Reserved buffer entries for GC I/O */
+	int rb_state;		/* Rate-limiter current state */
+	int rb_max_io;		/* Maximum size for an I/O giving the config */
+
+	atomic_t rb_user_cnt;	/* User I/O buffer counter */
+	atomic_t rb_gc_cnt;	/* GC I/O buffer counter */
+	atomic_t rb_space;	/* Space limit in case of reaching capacity */
+
+	int rsv_blocks;		/* Reserved blocks for GC */
+
+	int rb_user_active;
+	int rb_gc_active;
+
+	atomic_t werr_lines;	/* Number of write error lines that needs gc */
+
+	struct timer_list u_timer;
+
+	unsigned long long nr_secs;
+	unsigned long total_blocks;
+
+	atomic_t free_blocks;		/* Total number of free blocks (+ OP) */
+	atomic_t free_user_blocks;	/* Number of user free blocks (no OP) */
+};
+
+#define PBLK_LINE_EMPTY (~0U)
+
+enum {
+	/* Line Types */
+	PBLK_LINETYPE_FREE = 0,
+	PBLK_LINETYPE_LOG = 1,
+	PBLK_LINETYPE_DATA = 2,
+
+	/* Line state */
+	PBLK_LINESTATE_NEW = 9,
+	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,
+	PBLK_LINEGC_WERR = 26
+};
+
+#define PBLK_MAGIC 0x70626c6b /*pblk*/
+
+/* emeta/smeta persistent storage format versions:
+ * Changes in major version requires offline migration.
+ * Changes in minor version are handled automatically during
+ * recovery.
+ */
+
+#define SMETA_VERSION_MAJOR (0)
+#define SMETA_VERSION_MINOR (1)
+
+#define EMETA_VERSION_MAJOR (0)
+#define EMETA_VERSION_MINOR (2)
+
+struct line_header {
+	__le32 crc;
+	__le32 identifier;	/* pblk identifier */
+	__u8 uuid[16];		/* instance uuid */
+	__le16 type;		/* line type */
+	__u8 version_major;	/* version major */
+	__u8 version_minor;	/* version minor */
+	__le32 id;		/* line id for current line */
+};
+
+struct line_smeta {
+	struct line_header header;
+
+	__le32 crc;		/* Full structure including struct crc */
+	/* Previous line metadata */
+	__le32 prev_id;		/* Line id for previous line */
+
+	/* Current line metadata */
+	__le64 seq_nr;		/* Sequence number for current line */
+
+	/* Active writers */
+	__le32 window_wr_lun;	/* Number of parallel LUNs to write */
+
+	__le32 rsvd[2];
+
+	__le64 lun_bitmap[];
+};
+
+
+/*
+ * Metadata layout in media:
+ *	First sector:
+ *		1. struct line_emeta
+ *		2. bad block bitmap (u64 * window_wr_lun)
+ *		3. write amplification counters
+ *	Mid sectors (start at lbas_sector):
+ *		3. nr_lbas (u64) forming lba list
+ *	Last sectors (start at vsc_sector):
+ *		4. u32 valid sector count (vsc) for all lines (~0U: free line)
+ */
+struct line_emeta {
+	struct line_header header;
+
+	__le32 crc;		/* Full structure including struct crc */
+
+	/* Previous line metadata */
+	__le32 prev_id;		/* Line id for prev line */
+
+	/* Current line metadata */
+	__le64 seq_nr;		/* Sequence number for current line */
+
+	/* Active writers */
+	__le32 window_wr_lun;	/* Number of parallel LUNs to write */
+
+	/* Bookkeeping for recovery */
+	__le32 next_id;		/* Line id for next line */
+	__le64 nr_lbas;		/* Number of lbas mapped in line */
+	__le64 nr_valid_lbas;	/* Number of valid lbas mapped in line */
+	__le64 bb_bitmap[];     /* Updated bad block bitmap for line */
+};
+
+
+/* Write amplification counters stored on media */
+struct wa_counters {
+	__le64 user;		/* Number of user written sectors */
+	__le64 gc;		/* Number of sectors written by GC*/
+	__le64 pad;		/* Number of padded sectors */
+};
+
+struct pblk_emeta {
+	struct line_emeta *buf;		/* emeta buffer in media format */
+	int mem;			/* Write offset - points to next
+					 * writable entry in memory
+					 */
+	atomic_t sync;			/* Synced - backpointer that signals the
+					 * last entry that has been successfully
+					 * persisted to media
+					 */
+	unsigned int nr_entries;	/* Number of emeta entries */
+};
+
+struct pblk_smeta {
+	struct line_smeta *buf;		/* smeta buffer in persistent format */
+};
+
+struct pblk_w_err_gc {
+	int has_write_err;
+	__le64 *lba_list;
+};
+
+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 nvm_chk_meta *chks;	/* Chunks forming line */
+
+	struct pblk_smeta *smeta;	/* Start metadata */
+	struct pblk_emeta *emeta;	/* End medatada */
+
+	int meta_line;			/* Metadata line id */
+	int meta_distance;		/* Distance between data and metadata */
+
+	u64 smeta_ssec;			/* Sector where smeta starts */
+	u64 emeta_ssec;			/* Sector where emeta starts */
+
+	unsigned int sec_in_line;	/* Number of usable secs in line */
+
+	atomic_t 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 */
+
+	atomic_t left_eblks;		/* Blocks left for erasing */
+	atomic_t left_seblks;		/* Blocks left for sync erasing */
+
+	int left_msecs;			/* Sectors left for mapping */
+	unsigned int cur_sec;		/* Sector map pointer */
+	unsigned int nr_valid_lbas;	/* Number of valid lbas in line */
+
+	__le32 *vsc;			/* Valid sector count in line */
+
+	struct kref ref;		/* Write buffer L2P references */
+
+	struct pblk_w_err_gc *w_err_gc;	/* Write error gc recovery metadata */
+
+	spinlock_t lock;		/* Necessary for invalid_bitmap only */
+};
+
+#define PBLK_DATA_LINES 4
+
+enum {
+	PBLK_KMALLOC_META = 1,
+	PBLK_VMALLOC_META = 2,
+};
+
+enum {
+	PBLK_EMETA_TYPE_HEADER = 1,	/* struct line_emeta first sector */
+	PBLK_EMETA_TYPE_LLBA = 2,	/* lba list - type: __le64 */
+	PBLK_EMETA_TYPE_VSC = 3,	/* vsc list - type: __le32 */
+};
+
+struct pblk_line_mgmt {
+	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_GC_NR_LISTS];
+	struct list_head gc_high_list;	/* Full lines ready to GC, high isc */
+	struct list_head gc_mid_list;	/* Full lines ready to GC, mid isc */
+	struct list_head gc_low_list;	/* Full lines ready to GC, low isc */
+
+	struct list_head gc_werr_list;  /* Write err recovery list */
+
+	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 */
+
+	struct list_head emeta_list;	/* Lines queued to schedule emeta */
+
+	__le32 *vsc_list;		/* Valid sector counts for all lines */
+
+	/* Metadata allocation type: VMALLOC | KMALLOC */
+	int emeta_alloc_type;
+
+	/* Pre-allocated metadata for data lines */
+	struct pblk_smeta *sline_meta[PBLK_DATA_LINES];
+	struct pblk_emeta *eline_meta[PBLK_DATA_LINES];
+	unsigned long meta_bitmap;
+
+	/* Helpers for fast bitmap calculations */
+	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 close_lock;
+	spinlock_t gc_lock;
+};
+
+struct pblk_line_meta {
+	unsigned int smeta_len;		/* Total length for smeta */
+	unsigned int smeta_sec;		/* Sectors needed for smeta */
+
+	unsigned int emeta_len[4];	/* Lengths for emeta:
+					 *  [0]: Total
+					 *  [1]: struct line_emeta +
+					 *       bb_bitmap + struct wa_counters
+					 *  [2]: L2P portion
+					 *  [3]: vsc
+					 */
+	unsigned int emeta_sec[4];	/* Sectors needed for emeta. Same layout
+					 * as emeta_len
+					 */
+
+	unsigned int emeta_bb;		/* Boundary for bb that affects emeta */
+
+	unsigned int vsc_list_len;	/* Length for vsc list */
+	unsigned int sec_bitmap_len;	/* Length for sector bitmap in line */
+	unsigned int blk_bitmap_len;	/* Length for block bitmap in line */
+	unsigned int lun_bitmap_len;	/* Length for lun bitmap in line */
+
+	unsigned int blk_per_line;	/* Number of blocks in a full line */
+	unsigned int sec_per_line;	/* Number of sectors in a line */
+	unsigned int dsec_per_line;	/* Number of data sectors in a line */
+	unsigned int min_blk_line;	/* Min. number of good blocks in line */
+
+	unsigned int mid_thrs;		/* Threshold for GC mid list */
+	unsigned int high_thrs;		/* Threshold for GC high list */
+
+	unsigned int meta_distance;	/* Distance between data and metadata */
+};
+
+enum {
+	PBLK_STATE_RUNNING = 0,
+	PBLK_STATE_STOPPING = 1,
+	PBLK_STATE_RECOVERING = 2,
+	PBLK_STATE_STOPPED = 3,
+};
+
+/* Internal format to support not power-of-2 device formats */
+struct pblk_addrf {
+	/* gen to dev */
+	int sec_stripe;
+	int ch_stripe;
+	int lun_stripe;
+
+	/* dev to gen */
+	int sec_lun_stripe;
+	int sec_ws_stripe;
+};
+
+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 nvm_addrf addrf;		/* Aligned address format */
+	struct pblk_addrf uaddrf;	/* Unaligned address format */
+	int addrf_len;
+
+	struct pblk_rb rwb;
+
+	int state;			/* pblk line state */
+
+	int min_write_pgs; /* Minimum amount of pages required by controller */
+	int max_write_pgs; /* Maximum amount of pages supported by controller */
+
+	sector_t capacity; /* Device capacity when bad blocks are subtracted */
+
+	int op;      /* Percentage of device used for over-provisioning */
+	int op_blks; /* Number of blocks used for over-provisioning */
+
+	/* pblk provisioning values. Used by rate limiter */
+	struct pblk_rl rl;
+
+	int sec_per_write;
+
+	unsigned char instance_uuid[16];
+
+	/* Persistent write amplification counters, 4kb sector I/Os */
+	atomic64_t user_wa;		/* Sectors written by user */
+	atomic64_t gc_wa;		/* Sectors written by GC */
+	atomic64_t pad_wa;		/* Padded sectors written */
+
+	/* Reset values for delta write amplification measurements */
+	u64 user_rst_wa;
+	u64 gc_rst_wa;
+	u64 pad_rst_wa;
+
+	/* Counters used for calculating padding distribution */
+	atomic64_t *pad_dist;		/* Padding distribution buckets */
+	u64 nr_flush_rst;		/* Flushes reset value for pad dist.*/
+	atomic64_t nr_flush;		/* Number of flush/fua I/O */
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	/* Non-persistent debug counters, 4kb sector I/Os */
+	atomic_long_t inflight_writes;	/* Inflight writes (user and gc) */
+	atomic_long_t padded_writes;	/* Sectors padded due to flush/fua */
+	atomic_long_t padded_wb;	/* Sectors padded in write buffer */
+	atomic_long_t req_writes;	/* Sectors stored on write buffer */
+	atomic_long_t sub_writes;	/* Sectors submitted from buffer */
+	atomic_long_t sync_writes;	/* Sectors synced to media */
+	atomic_long_t inflight_reads;	/* Inflight sector read requests */
+	atomic_long_t cache_reads;	/* Read requests that hit the cache */
+	atomic_long_t sync_reads;	/* Completed sector read requests */
+	atomic_long_t recov_writes;	/* Sectors submitted from recovery */
+	atomic_long_t recov_gc_writes;	/* Sectors submitted from write GC */
+	atomic_long_t recov_gc_reads;	/* Sectors submitted from read GC */
+#endif
+
+	spinlock_t lock;
+
+	atomic_long_t read_failed;
+	atomic_long_t read_empty;
+	atomic_long_t read_high_ecc;
+	atomic_long_t read_failed_gc;
+	atomic_long_t write_failed;
+	atomic_long_t erase_failed;
+
+	atomic_t inflight_io;		/* General inflight I/O counter */
+
+	struct task_struct *writer_ts;
+
+	/* Simple translation map of logical addresses to physical addresses.
+	 * The logical addresses is known by the host system, while the physical
+	 * addresses are used when writing to the disk block device.
+	 */
+	unsigned char *trans_map;
+	spinlock_t trans_lock;
+
+	struct list_head compl_list;
+
+	spinlock_t resubmit_lock;	 /* Resubmit list lock */
+	struct list_head resubmit_list; /* Resubmit list for failed writes*/
+
+	mempool_t page_bio_pool;
+	mempool_t gen_ws_pool;
+	mempool_t rec_pool;
+	mempool_t r_rq_pool;
+	mempool_t w_rq_pool;
+	mempool_t e_rq_pool;
+
+	struct workqueue_struct *close_wq;
+	struct workqueue_struct *bb_wq;
+	struct workqueue_struct *r_end_wq;
+
+	struct timer_list wtimer;
+
+	struct pblk_gc gc;
+};
+
+struct pblk_line_ws {
+	struct pblk *pblk;
+	struct pblk_line *line;
+	void *priv;
+	struct work_struct ws;
+};
+
+#define pblk_g_rq_size (sizeof(struct nvm_rq) + sizeof(struct pblk_g_ctx))
+#define pblk_w_rq_size (sizeof(struct nvm_rq) + sizeof(struct pblk_c_ctx))
+
+#define pblk_err(pblk, fmt, ...)			\
+	pr_err("pblk %s: " fmt, pblk->disk->disk_name, ##__VA_ARGS__)
+#define pblk_info(pblk, fmt, ...)			\
+	pr_info("pblk %s: " fmt, pblk->disk->disk_name, ##__VA_ARGS__)
+#define pblk_warn(pblk, fmt, ...)			\
+	pr_warn("pblk %s: " fmt, pblk->disk->disk_name, ##__VA_ARGS__)
+#define pblk_debug(pblk, fmt, ...)			\
+	pr_debug("pblk %s: " fmt, pblk->disk->disk_name, ##__VA_ARGS__)
+
+/*
+ * 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);
+void pblk_rb_write_entry_user(struct pblk_rb *rb, void *data,
+			      struct pblk_w_ctx w_ctx, unsigned int pos);
+void pblk_rb_write_entry_gc(struct pblk_rb *rb, void *data,
+			    struct pblk_w_ctx w_ctx, struct pblk_line *line,
+			    u64 paddr, unsigned int pos);
+struct pblk_w_ctx *pblk_rb_w_ctx(struct pblk_rb *rb, unsigned int pos);
+void pblk_rb_flush(struct pblk_rb *rb);
+
+void pblk_rb_sync_l2p(struct pblk_rb *rb);
+unsigned int pblk_rb_read_to_bio(struct pblk_rb *rb, struct nvm_rq *rqd,
+				 unsigned int pos, unsigned int nr_entries,
+				 unsigned int count);
+int pblk_rb_copy_to_bio(struct pblk_rb *rb, struct bio *bio, sector_t lba,
+			struct ppa_addr ppa, int bio_iter, bool advanced_bio);
+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_flush_point_count(struct pblk_rb *rb);
+
+unsigned int pblk_rb_read_count(struct pblk_rb *rb);
+unsigned int pblk_rb_sync_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);
+
+/*
+ * pblk core
+ */
+struct nvm_rq *pblk_alloc_rqd(struct pblk *pblk, int type);
+void pblk_free_rqd(struct pblk *pblk, struct nvm_rq *rqd, int type);
+void pblk_set_sec_per_write(struct pblk *pblk, int sec_per_write);
+int pblk_setup_w_rec_rq(struct pblk *pblk, struct nvm_rq *rqd,
+			struct pblk_c_ctx *c_ctx);
+void pblk_discard(struct pblk *pblk, struct bio *bio);
+struct nvm_chk_meta *pblk_chunk_get_info(struct pblk *pblk);
+struct nvm_chk_meta *pblk_chunk_get_off(struct pblk *pblk,
+					      struct nvm_chk_meta *lp,
+					      struct ppa_addr ppa);
+void pblk_log_write_err(struct pblk *pblk, struct nvm_rq *rqd);
+void pblk_log_read_err(struct pblk *pblk, struct nvm_rq *rqd);
+int pblk_submit_io(struct pblk *pblk, struct nvm_rq *rqd);
+int pblk_submit_io_sync(struct pblk *pblk, struct nvm_rq *rqd);
+int pblk_submit_meta_io(struct pblk *pblk, struct pblk_line *meta_line);
+struct bio *pblk_bio_map_addr(struct pblk *pblk, void *data,
+			      unsigned int nr_secs, unsigned int len,
+			      int alloc_type, gfp_t gfp_mask);
+struct pblk_line *pblk_line_get(struct pblk *pblk);
+struct pblk_line *pblk_line_get_first_data(struct pblk *pblk);
+struct pblk_line *pblk_line_replace_data(struct pblk *pblk);
+int pblk_line_recov_alloc(struct pblk *pblk, struct pblk_line *line);
+void pblk_line_recov_close(struct pblk *pblk, struct pblk_line *line);
+struct pblk_line *pblk_line_get_data(struct pblk *pblk);
+struct pblk_line *pblk_line_get_erase(struct pblk *pblk);
+int pblk_line_erase(struct pblk *pblk, struct pblk_line *line);
+int pblk_line_is_full(struct pblk_line *line);
+void pblk_line_free(struct pblk_line *line);
+void pblk_line_close_meta(struct pblk *pblk, struct pblk_line *line);
+void pblk_line_close(struct pblk *pblk, struct pblk_line *line);
+void pblk_line_close_ws(struct work_struct *work);
+void pblk_pipeline_stop(struct pblk *pblk);
+void __pblk_pipeline_stop(struct pblk *pblk);
+void __pblk_pipeline_flush(struct pblk *pblk);
+void pblk_gen_run_ws(struct pblk *pblk, struct pblk_line *line, void *priv,
+		     void (*work)(struct work_struct *), gfp_t gfp_mask,
+		     struct workqueue_struct *wq);
+u64 pblk_line_smeta_start(struct pblk *pblk, struct pblk_line *line);
+int pblk_line_read_smeta(struct pblk *pblk, struct pblk_line *line);
+int pblk_line_read_emeta(struct pblk *pblk, struct pblk_line *line,
+			 void *emeta_buf);
+int pblk_blk_erase_async(struct pblk *pblk, struct ppa_addr erase_ppa);
+void pblk_line_put(struct kref *ref);
+void pblk_line_put_wq(struct kref *ref);
+struct list_head *pblk_line_gc_list(struct pblk *pblk, struct pblk_line *line);
+u64 pblk_lookup_page(struct pblk *pblk, struct pblk_line *line);
+void pblk_dealloc_page(struct pblk *pblk, struct pblk_line *line, int nr_secs);
+u64 pblk_alloc_page(struct pblk *pblk, struct pblk_line *line, int nr_secs);
+u64 __pblk_alloc_page(struct pblk *pblk, struct pblk_line *line, int nr_secs);
+int pblk_calc_secs(struct pblk *pblk, unsigned long secs_avail,
+		   unsigned long secs_to_flush);
+void pblk_up_page(struct pblk *pblk, struct ppa_addr *ppa_list, int nr_ppas);
+void pblk_down_rq(struct pblk *pblk, struct ppa_addr *ppa_list, int nr_ppas,
+		  unsigned long *lun_bitmap);
+void pblk_down_page(struct pblk *pblk, struct ppa_addr *ppa_list, int nr_ppas);
+void pblk_up_rq(struct pblk *pblk, struct ppa_addr *ppa_list, int nr_ppas,
+		unsigned long *lun_bitmap);
+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_map_invalidate(struct pblk *pblk, struct ppa_addr ppa);
+void __pblk_map_invalidate(struct pblk *pblk, struct pblk_line *line,
+			   u64 paddr);
+void pblk_update_map(struct pblk *pblk, sector_t lba, struct ppa_addr ppa);
+void pblk_update_map_cache(struct pblk *pblk, sector_t lba,
+			   struct ppa_addr ppa);
+void pblk_update_map_dev(struct pblk *pblk, sector_t lba,
+			 struct ppa_addr ppa, struct ppa_addr entry_line);
+int pblk_update_map_gc(struct pblk *pblk, sector_t lba, struct ppa_addr ppa,
+		       struct pblk_line *gc_line, u64 paddr);
+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);
+
+/*
+ * 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, struct pblk_gc_rq *gc_rq);
+
+/*
+ * pblk map
+ */
+void 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(struct timer_list *t);
+void pblk_write_should_kick(struct pblk *pblk);
+void pblk_write_kick(struct pblk *pblk);
+
+/*
+ * pblk read path
+ */
+extern struct bio_set pblk_bio_set;
+int pblk_submit_read(struct pblk *pblk, struct bio *bio);
+int pblk_submit_read_gc(struct pblk *pblk, struct pblk_gc_rq *gc_rq);
+/*
+ * pblk recovery
+ */
+struct pblk_line *pblk_recov_l2p(struct pblk *pblk);
+int pblk_recov_pad(struct pblk *pblk);
+int pblk_recov_check_emeta(struct pblk *pblk, struct line_emeta *emeta);
+
+/*
+ * pblk gc
+ */
+#define PBLK_GC_MAX_READERS 8	/* Max number of outstanding GC reader jobs */
+#define PBLK_GC_RQ_QD 128	/* Queue depth for inflight GC requests */
+#define PBLK_GC_L_QD 4		/* Queue depth for inflight GC lines */
+#define PBLK_GC_RSV_LINE 1	/* Reserved lines for GC */
+
+int pblk_gc_init(struct pblk *pblk);
+void pblk_gc_exit(struct pblk *pblk, bool graceful);
+void pblk_gc_should_start(struct pblk *pblk);
+void pblk_gc_should_stop(struct pblk *pblk);
+void pblk_gc_should_kick(struct pblk *pblk);
+void pblk_gc_free_full_lines(struct pblk *pblk);
+void pblk_gc_sysfs_state_show(struct pblk *pblk, int *gc_enabled,
+			      int *gc_active);
+int pblk_gc_sysfs_force(struct pblk *pblk, int force);
+
+/*
+ * pblk rate limiter
+ */
+void pblk_rl_init(struct pblk_rl *rl, int budget);
+void pblk_rl_free(struct pblk_rl *rl);
+void pblk_rl_update_rates(struct pblk_rl *rl);
+int pblk_rl_high_thrs(struct pblk_rl *rl);
+unsigned long pblk_rl_nr_free_blks(struct pblk_rl *rl);
+unsigned long pblk_rl_nr_user_free_blks(struct pblk_rl *rl);
+int pblk_rl_user_may_insert(struct pblk_rl *rl, int nr_entries);
+void pblk_rl_inserted(struct pblk_rl *rl, int nr_entries);
+void pblk_rl_user_in(struct pblk_rl *rl, int nr_entries);
+int pblk_rl_gc_may_insert(struct pblk_rl *rl, int nr_entries);
+void pblk_rl_gc_in(struct pblk_rl *rl, int nr_entries);
+void pblk_rl_out(struct pblk_rl *rl, int nr_user, int nr_gc);
+int pblk_rl_max_io(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,
+			    bool used);
+int pblk_rl_is_limit(struct pblk_rl *rl);
+
+void pblk_rl_werr_line_in(struct pblk_rl *rl);
+void pblk_rl_werr_line_out(struct pblk_rl *rl);
+
+/*
+ * 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 *emeta_to_bb(struct line_emeta *emeta)
+{
+	return emeta->bb_bitmap;
+}
+
+static inline void *emeta_to_wa(struct pblk_line_meta *lm,
+				struct line_emeta *emeta)
+{
+	return emeta->bb_bitmap + lm->blk_bitmap_len;
+}
+
+static inline void *emeta_to_lbas(struct pblk *pblk, struct line_emeta *emeta)
+{
+	return ((void *)emeta + pblk->lm.emeta_len[1]);
+}
+
+static inline void *emeta_to_vsc(struct pblk *pblk, struct line_emeta *emeta)
+{
+	return (emeta_to_lbas(pblk, emeta) + pblk->lm.emeta_len[2]);
+}
+
+static inline int pblk_line_vsc(struct pblk_line *line)
+{
+	return le32_to_cpu(*line->vsc);
+}
+
+static inline int pblk_pad_distance(struct pblk *pblk)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+
+	return geo->mw_cunits * geo->all_luns * geo->ws_opt;
+}
+
+static inline int pblk_ppa_to_line(struct ppa_addr p)
+{
+	return p.a.blk;
+}
+
+static inline int pblk_ppa_to_pos(struct nvm_geo *geo, struct ppa_addr p)
+{
+	return p.a.lun * geo->num_ch + p.a.ch;
+}
+
+static inline struct ppa_addr addr_to_gen_ppa(struct pblk *pblk, u64 paddr,
+					      u64 line_id)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	struct ppa_addr ppa;
+
+	if (geo->version == NVM_OCSSD_SPEC_12) {
+		struct nvm_addrf_12 *ppaf = (struct nvm_addrf_12 *)&pblk->addrf;
+
+		ppa.ppa = 0;
+		ppa.g.blk = line_id;
+		ppa.g.pg = (paddr & ppaf->pg_mask) >> ppaf->pg_offset;
+		ppa.g.lun = (paddr & ppaf->lun_mask) >> ppaf->lun_offset;
+		ppa.g.ch = (paddr & ppaf->ch_mask) >> ppaf->ch_offset;
+		ppa.g.pl = (paddr & ppaf->pln_mask) >> ppaf->pln_offset;
+		ppa.g.sec = (paddr & ppaf->sec_mask) >> ppaf->sec_offset;
+	} else {
+		struct pblk_addrf *uaddrf = &pblk->uaddrf;
+		int secs, chnls, luns;
+
+		ppa.ppa = 0;
+
+		ppa.m.chk = line_id;
+
+		paddr = div_u64_rem(paddr, uaddrf->sec_stripe, &secs);
+		ppa.m.sec = secs;
+
+		paddr = div_u64_rem(paddr, uaddrf->ch_stripe, &chnls);
+		ppa.m.grp = chnls;
+
+		paddr = div_u64_rem(paddr, uaddrf->lun_stripe, &luns);
+		ppa.m.pu = luns;
+
+		ppa.m.sec += uaddrf->sec_stripe * paddr;
+	}
+
+	return ppa;
+}
+
+static inline u64 pblk_dev_ppa_to_line_addr(struct pblk *pblk,
+							struct ppa_addr p)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	u64 paddr;
+
+	if (geo->version == NVM_OCSSD_SPEC_12) {
+		struct nvm_addrf_12 *ppaf = (struct nvm_addrf_12 *)&pblk->addrf;
+
+		paddr = (u64)p.g.ch << ppaf->ch_offset;
+		paddr |= (u64)p.g.lun << ppaf->lun_offset;
+		paddr |= (u64)p.g.pg << ppaf->pg_offset;
+		paddr |= (u64)p.g.pl << ppaf->pln_offset;
+		paddr |= (u64)p.g.sec << ppaf->sec_offset;
+	} else {
+		struct pblk_addrf *uaddrf = &pblk->uaddrf;
+		u64 secs = p.m.sec;
+		int sec_stripe;
+
+		paddr = (u64)p.m.grp * uaddrf->sec_stripe;
+		paddr += (u64)p.m.pu * uaddrf->sec_lun_stripe;
+
+		secs = div_u64_rem(secs, uaddrf->sec_stripe, &sec_stripe);
+		paddr += secs * uaddrf->sec_ws_stripe;
+		paddr += sec_stripe;
+	}
+
+	return paddr;
+}
+
+static inline struct ppa_addr pblk_ppa32_to_ppa64(struct pblk *pblk, u32 ppa32)
+{
+	struct ppa_addr ppa64;
+
+	ppa64.ppa = 0;
+
+	if (ppa32 == -1) {
+		ppa64.ppa = ADDR_EMPTY;
+	} else if (ppa32 & (1U << 31)) {
+		ppa64.c.line = ppa32 & ((~0U) >> 1);
+		ppa64.c.is_cached = 1;
+	} else {
+		struct nvm_tgt_dev *dev = pblk->dev;
+		struct nvm_geo *geo = &dev->geo;
+
+		if (geo->version == NVM_OCSSD_SPEC_12) {
+			struct nvm_addrf_12 *ppaf =
+					(struct nvm_addrf_12 *)&pblk->addrf;
+
+			ppa64.g.ch = (ppa32 & ppaf->ch_mask) >>
+							ppaf->ch_offset;
+			ppa64.g.lun = (ppa32 & ppaf->lun_mask) >>
+							ppaf->lun_offset;
+			ppa64.g.blk = (ppa32 & ppaf->blk_mask) >>
+							ppaf->blk_offset;
+			ppa64.g.pg = (ppa32 & ppaf->pg_mask) >>
+							ppaf->pg_offset;
+			ppa64.g.pl = (ppa32 & ppaf->pln_mask) >>
+							ppaf->pln_offset;
+			ppa64.g.sec = (ppa32 & ppaf->sec_mask) >>
+							ppaf->sec_offset;
+		} else {
+			struct nvm_addrf *lbaf = &pblk->addrf;
+
+			ppa64.m.grp = (ppa32 & lbaf->ch_mask) >>
+							lbaf->ch_offset;
+			ppa64.m.pu = (ppa32 & lbaf->lun_mask) >>
+							lbaf->lun_offset;
+			ppa64.m.chk = (ppa32 & lbaf->chk_mask) >>
+							lbaf->chk_offset;
+			ppa64.m.sec = (ppa32 & lbaf->sec_mask) >>
+							lbaf->sec_offset;
+		}
+	}
+
+	return ppa64;
+}
+
+static inline u32 pblk_ppa64_to_ppa32(struct pblk *pblk, struct ppa_addr ppa64)
+{
+	u32 ppa32 = 0;
+
+	if (ppa64.ppa == ADDR_EMPTY) {
+		ppa32 = ~0U;
+	} else if (ppa64.c.is_cached) {
+		ppa32 |= ppa64.c.line;
+		ppa32 |= 1U << 31;
+	} else {
+		struct nvm_tgt_dev *dev = pblk->dev;
+		struct nvm_geo *geo = &dev->geo;
+
+		if (geo->version == NVM_OCSSD_SPEC_12) {
+			struct nvm_addrf_12 *ppaf =
+					(struct nvm_addrf_12 *)&pblk->addrf;
+
+			ppa32 |= ppa64.g.ch << ppaf->ch_offset;
+			ppa32 |= ppa64.g.lun << ppaf->lun_offset;
+			ppa32 |= ppa64.g.blk << ppaf->blk_offset;
+			ppa32 |= ppa64.g.pg << ppaf->pg_offset;
+			ppa32 |= ppa64.g.pl << ppaf->pln_offset;
+			ppa32 |= ppa64.g.sec << ppaf->sec_offset;
+		} else {
+			struct nvm_addrf *lbaf = &pblk->addrf;
+
+			ppa32 |= ppa64.m.grp << lbaf->ch_offset;
+			ppa32 |= ppa64.m.pu << lbaf->lun_offset;
+			ppa32 |= ppa64.m.chk << lbaf->chk_offset;
+			ppa32 |= ppa64.m.sec << lbaf->sec_offset;
+		}
+	}
+
+	return ppa32;
+}
+
+static inline struct ppa_addr pblk_trans_map_get(struct pblk *pblk,
+								sector_t lba)
+{
+	struct ppa_addr ppa;
+
+	if (pblk->addrf_len < 32) {
+		u32 *map = (u32 *)pblk->trans_map;
+
+		ppa = pblk_ppa32_to_ppa64(pblk, map[lba]);
+	} else {
+		struct ppa_addr *map = (struct ppa_addr *)pblk->trans_map;
+
+		ppa = map[lba];
+	}
+
+	return ppa;
+}
+
+static inline void pblk_trans_map_set(struct pblk *pblk, sector_t lba,
+						struct ppa_addr ppa)
+{
+	if (pblk->addrf_len < 32) {
+		u32 *map = (u32 *)pblk->trans_map;
+
+		map[lba] = pblk_ppa64_to_ppa32(pblk, ppa);
+	} else {
+		u64 *map = (u64 *)pblk->trans_map;
+
+		map[lba] = ppa.ppa;
+	}
+}
+
+static inline int pblk_ppa_empty(struct ppa_addr ppa_addr)
+{
+	return (ppa_addr.ppa == ADDR_EMPTY);
+}
+
+static inline void pblk_ppa_set_empty(struct ppa_addr *ppa_addr)
+{
+	ppa_addr->ppa = ADDR_EMPTY;
+}
+
+static inline bool pblk_ppa_comp(struct ppa_addr lppa, struct ppa_addr rppa)
+{
+	return (lppa.ppa == rppa.ppa);
+}
+
+static inline int pblk_addr_in_cache(struct ppa_addr ppa)
+{
+	return (ppa.ppa != ADDR_EMPTY && ppa.c.is_cached);
+}
+
+static inline int pblk_addr_to_cacheline(struct ppa_addr ppa)
+{
+	return ppa.c.line;
+}
+
+static inline struct ppa_addr pblk_cacheline_to_addr(int addr)
+{
+	struct ppa_addr p;
+
+	p.c.line = addr;
+	p.c.is_cached = 1;
+
+	return p;
+}
+
+static inline u32 pblk_calc_meta_header_crc(struct pblk *pblk,
+					    struct line_header *header)
+{
+	u32 crc = ~(u32)0;
+
+	crc = crc32_le(crc, (unsigned char *)header + sizeof(crc),
+				sizeof(struct line_header) - sizeof(crc));
+
+	return crc;
+}
+
+static inline u32 pblk_calc_smeta_crc(struct pblk *pblk,
+				      struct line_smeta *smeta)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	u32 crc = ~(u32)0;
+
+	crc = crc32_le(crc, (unsigned char *)smeta +
+				sizeof(struct line_header) + sizeof(crc),
+				lm->smeta_len -
+				sizeof(struct line_header) - sizeof(crc));
+
+	return crc;
+}
+
+static inline u32 pblk_calc_emeta_crc(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(struct line_header) + sizeof(crc),
+				lm->emeta_len[0] -
+				sizeof(struct line_header) - sizeof(crc));
+
+	return crc;
+}
+
+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;
+
+	if (geo->version == NVM_OCSSD_SPEC_20)
+		return 0;
+
+	flags = geo->pln_mode >> 1;
+
+	if (type == PBLK_WRITE)
+		flags |= NVM_IO_SCRAMBLE_ENABLE;
+
+	return flags;
+}
+
+enum {
+	PBLK_READ_RANDOM	= 0,
+	PBLK_READ_SEQUENTIAL	= 1,
+};
+
+static inline int pblk_set_read_mode(struct pblk *pblk, int type)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	int flags;
+
+	if (geo->version == NVM_OCSSD_SPEC_20)
+		return 0;
+
+	flags = NVM_IO_SUSPEND | NVM_IO_SCRAMBLE_ENABLE;
+	if (type == PBLK_READ_SEQUENTIAL)
+		flags |= geo->pln_mode >> 1;
+
+	return flags;
+}
+
+static inline int pblk_io_aligned(struct pblk *pblk, int nr_secs)
+{
+	return !(nr_secs % pblk->min_write_pgs);
+}
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+static inline void print_ppa(struct pblk *pblk, struct ppa_addr *p,
+			     char *msg, int error)
+{
+	struct nvm_geo *geo = &pblk->dev->geo;
+
+	if (p->c.is_cached) {
+		pblk_err(pblk, "ppa: (%s: %x) cache line: %llu\n",
+				msg, error, (u64)p->c.line);
+	} else if (geo->version == NVM_OCSSD_SPEC_12) {
+		pblk_err(pblk, "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);
+	} else {
+		pblk_err(pblk, "ppa: (%s: %x):ch:%d,lun:%d,chk:%d,sec:%d\n",
+			msg, error,
+			p->m.grp, p->m.pu, p->m.chk, p->m.sec);
+	}
+}
+
+static inline void pblk_print_failed_rqd(struct pblk *pblk, struct nvm_rq *rqd,
+					 int error)
+{
+	int bit = -1;
+
+	if (rqd->nr_ppas ==  1) {
+		print_ppa(pblk, &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(pblk, &rqd->ppa_list[bit], "rqd", error);
+	}
+
+	pblk_err(pblk, "error:%d, ppa_status:%llx\n", error, rqd->ppa_status);
+}
+
+static inline int pblk_boundary_ppa_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 (geo->version == NVM_OCSSD_SPEC_12) {
+			if (!ppa->c.is_cached &&
+					ppa->g.ch < geo->num_ch &&
+					ppa->g.lun < geo->num_lun &&
+					ppa->g.pl < geo->num_pln &&
+					ppa->g.blk < geo->num_chk &&
+					ppa->g.pg < geo->num_pg &&
+					ppa->g.sec < geo->ws_min)
+				continue;
+		} else {
+			if (!ppa->c.is_cached &&
+					ppa->m.grp < geo->num_ch &&
+					ppa->m.pu < geo->num_lun &&
+					ppa->m.chk < geo->num_chk &&
+					ppa->m.sec < geo->clba)
+				continue;
+		}
+
+		print_ppa(tgt_dev->q->queuedata, ppa, "boundary", i);
+
+		return 1;
+	}
+	return 0;
+}
+
+static inline int pblk_check_io(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct ppa_addr *ppa_list;
+
+	ppa_list = (rqd->nr_ppas > 1) ? rqd->ppa_list : &rqd->ppa_addr;
+
+	if (pblk_boundary_ppa_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) {
+				pblk_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);
+		}
+	}
+
+	return 0;
+}
+#endif
+
+static inline int pblk_boundary_paddr_checks(struct pblk *pblk, u64 paddr)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+
+	if (paddr > lm->sec_per_line)
+		return 1;
+
+	return 0;
+}
+
+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 void pblk_setup_uuid(struct pblk *pblk)
+{
+	uuid_le uuid;
+
+	uuid_le_gen(&uuid);
+	memcpy(pblk->instance_uuid, uuid.b, 16);
+}
+#endif /* PBLK_H_ */