Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1324 insertions, 0 deletions

diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
new file mode 100644
index 000000000..b6246f738
--- /dev/null
+++ b/drivers/lightnvm/pblk-init.c
@@ -0,0 +1,1324 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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"
+#include "pblk-trace.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");
+
+struct pblk_global_caches {
+	struct kmem_cache	*ws;
+	struct kmem_cache	*rec;
+	struct kmem_cache	*g_rq;
+	struct kmem_cache	*w_rq;
+
+	struct kref		kref;
+
+	struct mutex		mutex; /* Ensures consistency between
+					* caches and kref
+					*/
+};
+
+static struct pblk_global_caches pblk_caches = {
+	.mutex = __MUTEX_INITIALIZER(pblk_caches.mutex),
+	.kref = KREF_INIT(0),
+};
+
+struct bio_set pblk_bio_set;
+
+static blk_qc_t pblk_submit_bio(struct bio *bio)
+{
+	struct pblk *pblk = bio->bi_disk->queue->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;
+		}
+	}
+
+	/* 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(&bio);
+		pblk_submit_read(pblk, bio);
+	} else {
+		/* 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(&bio);
+
+		pblk_write_to_cache(pblk, bio, PBLK_IOTYPE_USER);
+	}
+
+	return BLK_QC_T_NONE;
+}
+
+static const struct block_device_operations pblk_bops = {
+	.owner		= THIS_MODULE,
+	.submit_bio	= pblk_submit_bio,
+};
+
+
+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->capacity;
+}
+
+#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) {
+		guid_gen(&pblk->instance_uuid);
+	} 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, GFP_KERNEL | __GFP_NOWARN |
+				    __GFP_RETRY_MAYFAIL | __GFP_HIGHMEM);
+	if (!pblk->trans_map) {
+		pblk_err(pblk, "failed to allocate L2P (need %zu of memory)\n",
+				map_size);
+		return -ENOMEM;
+	}
+
+	pblk_ppa_set_empty(&ppa);
+
+	for (i = 0; i < pblk->capacity; 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_free(&pblk->rwb);
+}
+
+static int pblk_rwb_init(struct pblk *pblk)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct nvm_geo *geo = &dev->geo;
+	unsigned long buffer_size;
+	int pgs_in_buffer, threshold;
+
+	threshold = geo->mw_cunits * geo->all_luns;
+	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;
+
+	return pblk_rb_init(&pblk->rwb, buffer_size, threshold, geo->csecs);
+}
+
+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_create_global_caches(void)
+{
+
+	pblk_caches.ws = kmem_cache_create("pblk_blk_ws",
+				sizeof(struct pblk_line_ws), 0, 0, NULL);
+	if (!pblk_caches.ws)
+		return -ENOMEM;
+
+	pblk_caches.rec = kmem_cache_create("pblk_rec",
+				sizeof(struct pblk_rec_ctx), 0, 0, NULL);
+	if (!pblk_caches.rec)
+		goto fail_destroy_ws;
+
+	pblk_caches.g_rq = kmem_cache_create("pblk_g_rq", pblk_g_rq_size,
+				0, 0, NULL);
+	if (!pblk_caches.g_rq)
+		goto fail_destroy_rec;
+
+	pblk_caches.w_rq = kmem_cache_create("pblk_w_rq", pblk_w_rq_size,
+				0, 0, NULL);
+	if (!pblk_caches.w_rq)
+		goto fail_destroy_g_rq;
+
+	return 0;
+
+fail_destroy_g_rq:
+	kmem_cache_destroy(pblk_caches.g_rq);
+fail_destroy_rec:
+	kmem_cache_destroy(pblk_caches.rec);
+fail_destroy_ws:
+	kmem_cache_destroy(pblk_caches.ws);
+
+	return -ENOMEM;
+}
+
+static int pblk_get_global_caches(void)
+{
+	int ret = 0;
+
+	mutex_lock(&pblk_caches.mutex);
+
+	if (kref_get_unless_zero(&pblk_caches.kref))
+		goto out;
+
+	ret = pblk_create_global_caches();
+	if (!ret)
+		kref_init(&pblk_caches.kref);
+
+out:
+	mutex_unlock(&pblk_caches.mutex);
+	return ret;
+}
+
+static void pblk_destroy_global_caches(struct kref *ref)
+{
+	struct pblk_global_caches *c;
+
+	c = container_of(ref, struct pblk_global_caches, kref);
+
+	kmem_cache_destroy(c->ws);
+	kmem_cache_destroy(c->rec);
+	kmem_cache_destroy(c->g_rq);
+	kmem_cache_destroy(c->w_rq);
+}
+
+static void pblk_put_global_caches(void)
+{
+	mutex_lock(&pblk_caches.mutex);
+	kref_put(&pblk_caches.kref, pblk_destroy_global_caches);
+	mutex_unlock(&pblk_caches.mutex);
+}
+
+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;
+	pblk->min_write_pgs_data = pblk->min_write_pgs;
+	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);
+
+	pblk->oob_meta_size = geo->sos;
+	if (!pblk_is_oob_meta_supported(pblk)) {
+		/* For drives which does not have OOB metadata feature
+		 * in order to support recovery feature we need to use
+		 * so called packed metadata. Packed metada will store
+		 * the same information as OOB metadata (l2p table mapping,
+		 * but in the form of the single page at the end of
+		 * every write request.
+		 */
+		if (pblk->min_write_pgs
+			* sizeof(struct pblk_sec_meta) > PAGE_SIZE) {
+			/* We want to keep all the packed metadata on single
+			 * page per write requests. So we need to ensure that
+			 * it will fit.
+			 *
+			 * This is more like sanity check, since there is
+			 * no device with such a big minimal write size
+			 * (above 1 metabytes).
+			 */
+			pblk_err(pblk, "Not supported min write size\n");
+			return -EINVAL;
+		}
+		/* For packed meta approach we do some simplification.
+		 * On read path we always issue requests which size
+		 * equal to max_write_pgs, with all pages filled with
+		 * user payload except of last one page which will be
+		 * filled with packed metadata.
+		 */
+		pblk->max_write_pgs = pblk->min_write_pgs;
+		pblk->min_write_pgs_data = pblk->min_write_pgs - 1;
+	}
+
+	pblk->pad_dist = kcalloc(pblk->min_write_pgs - 1, sizeof(atomic64_t),
+								GFP_KERNEL);
+	if (!pblk->pad_dist)
+		return -ENOMEM;
+
+	if (pblk_get_global_caches())
+		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_caches.ws);
+	if (ret)
+		goto free_page_bio_pool;
+
+	ret = mempool_init_slab_pool(&pblk->rec_pool, geo->all_luns,
+				     pblk_caches.rec);
+	if (ret)
+		goto free_gen_ws_pool;
+
+	ret = mempool_init_slab_pool(&pblk->r_rq_pool, geo->all_luns,
+				     pblk_caches.g_rq);
+	if (ret)
+		goto free_rec_pool;
+
+	ret = mempool_init_slab_pool(&pblk->e_rq_pool, geo->all_luns,
+				     pblk_caches.g_rq);
+	if (ret)
+		goto free_r_rq_pool;
+
+	ret = mempool_init_slab_pool(&pblk->w_rq_pool, geo->all_luns,
+				     pblk_caches.w_rq);
+	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_put_global_caches();
+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_put_global_caches();
+	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]);
+		kvfree(l_mg->eline_meta[i]->buf);
+		kfree(l_mg->eline_meta[i]);
+	}
+
+	mempool_destroy(l_mg->bitmap_pool);
+	kmem_cache_destroy(l_mg->bitmap_cache);
+}
+
+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);
+
+	kvfree(w_err_gc->lba_list);
+	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;
+
+	for (i = 0; i < l_mg->nr_lines; i++) {
+		line = &pblk->lines[i];
+
+		pblk_line_free(line);
+		pblk_line_meta_free(l_mg, line);
+	}
+
+	pblk_line_mg_free(pblk);
+
+	kfree(pblk->luns);
+	kfree(pblk->lines);
+}
+
+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 int pblk_set_provision(struct pblk *pblk, int nr_free_chks)
+{
+	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, clba;
+	int minimum;
+
+	if (geo->op == NVM_TARGET_DEFAULT_OP)
+		pblk->op = PBLK_DEFAULT_OP;
+	else
+		pblk->op = geo->op;
+
+	minimum = pblk_get_min_chks(pblk);
+	provisioned = nr_free_chks;
+	provisioned *= (100 - pblk->op);
+	sector_div(provisioned, 100);
+
+	if ((nr_free_chks - provisioned) < minimum) {
+		if (geo->op != NVM_TARGET_DEFAULT_OP) {
+			pblk_err(pblk, "OP too small to create a sane instance\n");
+			return -EINTR;
+		}
+
+		/* If the user did not specify an OP value, and PBLK_DEFAULT_OP
+		 * is not enough, calculate and set sane value
+		 */
+
+		provisioned = nr_free_chks - minimum;
+		pblk->op =  (100 * minimum) / nr_free_chks;
+		pblk_info(pblk, "Default OP insufficient, adjusting OP to %d\n",
+				pblk->op);
+	}
+
+	pblk->op_blks = nr_free_chks - provisioned;
+
+	/* Internally pblk manages all free blocks, but all calculations based
+	 * on user capacity consider only provisioned blocks
+	 */
+	pblk->rl.total_blocks = nr_free_chks;
+
+	/* 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);
+
+	clba = (geo->clba / pblk->min_write_pgs) * pblk->min_write_pgs_data;
+	pblk->capacity = (provisioned - blk_meta) * clba;
+
+	atomic_set(&pblk->rl.free_blocks, nr_free_chks);
+	atomic_set(&pblk->rl.free_user_blocks, nr_free_chks);
+
+	return 0;
+}
+
+static int pblk_setup_line_meta_chk(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;
+
+		trace_pblk_chunk_state(pblk_disk_name(pblk), &ppa,
+					chunk->state);
+
+		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 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);
+
+	nr_bad_chks = pblk_setup_line_meta_chk(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;
+	}
+
+	l_mg->bitmap_cache = kmem_cache_create("pblk_lm_bitmap",
+			lm->sec_bitmap_len, 0, 0, NULL);
+	if (!l_mg->bitmap_cache)
+		goto fail_free_smeta;
+
+	/* the bitmap pool is used for both valid and map bitmaps */
+	l_mg->bitmap_pool = mempool_create_slab_pool(PBLK_DATA_LINES * 2,
+				l_mg->bitmap_cache);
+	if (!l_mg->bitmap_pool)
+		goto fail_destroy_bitmap_cache;
+
+	/* 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;
+
+		emeta->buf = kvmalloc(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) {
+		kvfree(l_mg->eline_meta[i]->buf);
+		kfree(l_mg->eline_meta[i]);
+	}
+
+	mempool_destroy(l_mg->bitmap_pool);
+fail_destroy_bitmap_cache:
+	kmem_cache_destroy(l_mg->bitmap_cache);
+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;
+	int 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_get_chunk_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);
+
+		trace_pblk_line_state(pblk_disk_name(pblk), line->id,
+								line->state);
+	}
+
+	if (!nr_free_chks) {
+		pblk_err(pblk, "too many bad blocks prevent for sane instance\n");
+		ret = -EINTR;
+		goto fail_free_lines;
+	}
+
+	ret = pblk_set_provision(pblk, nr_free_chks);
+	if (ret)
+		goto fail_free_lines;
+
+	vfree(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:
+	vfree(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;
+
+	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);
+}
+
+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;
+	trace_pblk_state(pblk_disk_name(pblk), pblk->state);
+	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->ext) {
+		pblk_err(pblk, "extended metadata not supported\n");
+		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->capacity,
+			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},
+
+	.bops		= &pblk_bops,
+	.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");