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Subject: Re: [PATCH] lightnvm: pblk: refactor init/exit sequences
To:     =?UTF-8?Q?Javier_Gonz=c3=a1lez?= <javier@javigon.com>
Cc:     linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        dan.carpenter@oracle.com,
        =?UTF-8?Q?Javier_Gonz=c3=a1lez?= <javier@cnexlabs.com>
References: <1519919998-20829-1-git-send-email-javier@cnexlabs.com>
 <1519919998-20829-2-git-send-email-javier@cnexlabs.com>
From:   =?UTF-8?Q?Matias_Bj=c3=b8rling?= <mb@lightnvm.io>
Message-ID: <8586a9e4-c76f-e38a-edcf-201cc7e2ddfb@lightnvm.io>
Date:   Thu, 1 Mar 2018 19:49:44 +0100
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On 03/01/2018 04:59 PM, Javier González wrote:
> Refactor init and exit sequences to eliminate dependencies among init
> modules and improve readability.
> 
> Signed-off-by: Javier González <javier@cnexlabs.com>
> ---
>   drivers/lightnvm/pblk-init.c | 415 +++++++++++++++++++++----------------------
>   1 file changed, 206 insertions(+), 209 deletions(-)
> 
> diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
> index 25fc70ca07f7..87c390667dd6 100644
> --- a/drivers/lightnvm/pblk-init.c
> +++ b/drivers/lightnvm/pblk-init.c
> @@ -103,7 +103,40 @@ static void pblk_l2p_free(struct pblk *pblk)
>   	vfree(pblk->trans_map);
>   }
>   
> -static int pblk_l2p_init(struct pblk *pblk)
> +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)) {
> +			pr_err("pblk: could not recover l2p table\n");
> +			return -EFAULT;
> +		}
> +	}
> +
> +#ifdef CONFIG_NVM_DEBUG
> +	pr_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) {
> +			pr_err("pblk: line list corrupted\n");
> +			return -EFAULT;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static int pblk_l2p_init(struct pblk *pblk, bool factory_init)
>   {
>   	sector_t i;
>   	struct ppa_addr ppa;
> @@ -119,7 +152,7 @@ static int pblk_l2p_init(struct pblk *pblk)
>   	for (i = 0; i < pblk->rl.nr_secs; i++)
>   		pblk_trans_map_set(pblk, i, ppa);
>   
> -	return 0;
> +	return pblk_l2p_recover(pblk, factory_init);
>   }
>   
>   static void pblk_rwb_free(struct pblk *pblk)
> @@ -159,7 +192,13 @@ static int pblk_set_ppaf(struct pblk *pblk)
>   	struct nvm_tgt_dev *dev = pblk->dev;
>   	struct nvm_geo *geo = &dev->geo;
>   	struct nvm_addr_format ppaf = geo->ppaf;
> -	int power_len;
> +	int mod, power_len;
> +
> +	div_u64_rem(geo->sec_per_chk, pblk->min_write_pgs, &mod);
> +	if (mod) {
> +		pr_err("pblk: bad configuration of sectors/pages\n");
> +		return -EINVAL;
> +	}
>   
>   	/* Re-calculate channel and lun format to adapt to configuration */
>   	power_len = get_count_order(geo->nr_chnls);
> @@ -252,12 +291,39 @@ static int pblk_core_init(struct pblk *pblk)
>   {
>   	struct nvm_tgt_dev *dev = pblk->dev;
>   	struct nvm_geo *geo = &dev->geo;
> +	int max_write_ppas;
> +
> +	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->pgs_in_buffer = NVM_MEM_PAGE_WRITE * geo->sec_per_pg *
>   						geo->nr_planes * geo->all_luns;
>   
> +	pblk->min_write_pgs = geo->sec_per_pl * (geo->sec_size / PAGE_SIZE);
> +	max_write_ppas = pblk->min_write_pgs * geo->all_luns;
> +	pblk->max_write_pgs = min_t(int, max_write_ppas, NVM_MAX_VLBA);
> +	pblk_set_sec_per_write(pblk, pblk->min_write_pgs);
> +
> +	if (pblk->max_write_pgs > PBLK_MAX_REQ_ADDRS) {
> +		pr_err("pblk: vector list too big(%u > %u)\n",
> +				pblk->max_write_pgs, PBLK_MAX_REQ_ADDRS);
> +		return -EINVAL;
> +	}
> +
> +	pblk->pad_dist = kzalloc((pblk->min_write_pgs - 1) * sizeof(atomic64_t),
> +								GFP_KERNEL);
> +	if (!pblk->pad_dist)
> +		return -ENOMEM;
> +
>   	if (pblk_init_global_caches(pblk))
> -		return -ENOMEM;
> +		goto fail_free_pad_dist;
>   
>   	/* Internal bios can be at most the sectors signaled by the device. */
>   	pblk->page_bio_pool = mempool_create_page_pool(NVM_MAX_VLBA, 0);
> @@ -307,10 +373,8 @@ static int pblk_core_init(struct pblk *pblk)
>   	if (pblk_set_ppaf(pblk))
>   		goto free_r_end_wq;
>   
> -	if (pblk_rwb_init(pblk))
> -		goto free_r_end_wq;
> -
>   	INIT_LIST_HEAD(&pblk->compl_list);
> +
>   	return 0;
>   
>   free_r_end_wq:
> @@ -333,6 +397,8 @@ static int pblk_core_init(struct pblk *pblk)
>   	mempool_destroy(pblk->page_bio_pool);
>   free_global_caches:
>   	pblk_free_global_caches(pblk);
> +fail_free_pad_dist:
> +	kfree(pblk->pad_dist);
>   	return -ENOMEM;
>   }
>   
> @@ -354,14 +420,8 @@ static void pblk_core_free(struct pblk *pblk)
>   	mempool_destroy(pblk->e_rq_pool);
>   	mempool_destroy(pblk->w_rq_pool);
>   
> -	pblk_rwb_free(pblk);
> -
>   	pblk_free_global_caches(pblk);
> -}
> -
> -static void pblk_luns_free(struct pblk *pblk)
> -{
> -	kfree(pblk->luns);
> +	kfree(pblk->pad_dist);
>   }
>   
>   static void pblk_line_mg_free(struct pblk *pblk)
> @@ -378,8 +438,6 @@ static void pblk_line_mg_free(struct pblk *pblk)
>   		pblk_mfree(l_mg->eline_meta[i]->buf, l_mg->emeta_alloc_type);
>   		kfree(l_mg->eline_meta[i]);
>   	}
> -
> -	kfree(pblk->lines);
>   }
>   
>   static void pblk_line_meta_free(struct pblk_line *line)
> @@ -402,6 +460,11 @@ static void pblk_lines_free(struct pblk *pblk)
>   		pblk_line_meta_free(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,
> @@ -476,7 +539,7 @@ static int pblk_bb_line(struct pblk *pblk, struct pblk_line *line,
>   	return bb_cnt;
>   }
>   
> -static int pblk_luns_init(struct pblk *pblk, struct ppa_addr *luns)
> +static int pblk_luns_init(struct pblk *pblk)
>   {
>   	struct nvm_tgt_dev *dev = pblk->dev;
>   	struct nvm_geo *geo = &dev->geo;
> @@ -501,7 +564,7 @@ static int pblk_luns_init(struct pblk *pblk, struct ppa_addr *luns)
>   		int lunid = lun_raw + ch * geo->nr_luns;
>   
>   		rlun = &pblk->luns[i];
> -		rlun->bppa = luns[lunid];
> +		rlun->bppa = dev->luns[lunid];
>   
>   		sema_init(&rlun->wr_sem, 1);
>   	}
> @@ -509,38 +572,6 @@ static int pblk_luns_init(struct pblk *pblk, struct ppa_addr *luns)
>   	return 0;
>   }
>   
> -static int pblk_lines_configure(struct pblk *pblk, int flags)
> -{
> -	struct pblk_line *line = NULL;
> -	int ret = 0;
> -
> -	if (!(flags & NVM_TARGET_FACTORY)) {
> -		line = pblk_recov_l2p(pblk);
> -		if (IS_ERR(line)) {
> -			pr_err("pblk: could not recover l2p table\n");
> -			ret = -EFAULT;
> -		}
> -	}
> -
> -#ifdef CONFIG_NVM_DEBUG
> -	pr_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) {
> -			pr_err("pblk: line list corrupted\n");
> -			ret = -EFAULT;
> -		}
> -	}
> -
> -	return ret;
> -}
> -
>   /* See comment over struct line_emeta definition */
>   static unsigned int calc_emeta_len(struct pblk *pblk)
>   {
> @@ -606,11 +637,70 @@ static void pblk_set_provision(struct pblk *pblk, long nr_free_blks)
>   	atomic_set(&pblk->rl.free_user_blocks, nr_free_blks);
>   }
>   
> -static int pblk_lines_alloc_metadata(struct pblk *pblk)
> +static int pblk_setup_line_meta(struct pblk *pblk, struct pblk_line *line,
> +				void *chunk_log, long *nr_bad_blks)
>   {
> +	struct pblk_line_meta *lm = &pblk->lm;
> +
> +	line->blk_bitmap = kzalloc(lm->blk_bitmap_len, GFP_KERNEL);
> +	if (!line->blk_bitmap)
> +		return -ENOMEM;
> +
> +	line->erase_bitmap = kzalloc(lm->blk_bitmap_len, GFP_KERNEL);
> +	if (!line->erase_bitmap) {
> +		kfree(line->blk_bitmap);
> +		return -ENOMEM;
> +	}
> +
> +	*nr_bad_blks = pblk_bb_line(pblk, line, chunk_log, lm->blk_per_line);
> +
> +	return 0;
> +}
> +
> +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;
> +	int i, bb_distance;
> +
> +	l_mg->nr_lines = geo->nr_chks;
> +	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->emeta_list);
> +
> +	l_mg->gc_lists[0] = &l_mg->gc_high_list;
> +	l_mg->gc_lists[1] = &l_mg->gc_mid_list;
> +	l_mg->gc_lists[2] = &l_mg->gc_low_list;
> +
> +	spin_lock_init(&l_mg->free_lock);
> +	spin_lock_init(&l_mg->close_lock);
> +	spin_lock_init(&l_mg->gc_lock);
> +
> +	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
> @@ -656,13 +746,13 @@ static int pblk_lines_alloc_metadata(struct pblk *pblk)
>   		}
>   	}
>   
> -	l_mg->vsc_list = kcalloc(l_mg->nr_lines, sizeof(__le32), GFP_KERNEL);
> -	if (!l_mg->vsc_list)
> -		goto fail_free_emeta;
> -
>   	for (i = 0; i < l_mg->nr_lines; i++)
>   		l_mg->vsc_list[i] = cpu_to_le32(EMPTY_ENTRY);
>   
> +	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:
> @@ -673,69 +763,25 @@ static int pblk_lines_alloc_metadata(struct pblk *pblk)
>   			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_setup_line_meta(struct pblk *pblk, struct pblk_line *line,
> -				void *chunk_log, long *nr_bad_blks)
> -{
> -	struct pblk_line_meta *lm = &pblk->lm;
> -
> -	line->blk_bitmap = kzalloc(lm->blk_bitmap_len, GFP_KERNEL);
> -	if (!line->blk_bitmap)
> -		return -ENOMEM;
> -
> -	line->erase_bitmap = kzalloc(lm->blk_bitmap_len, GFP_KERNEL);
> -	if (!line->erase_bitmap) {
> -		kfree(line->blk_bitmap);
> -		return -ENOMEM;
> -	}
> -
> -	*nr_bad_blks = pblk_bb_line(pblk, line, chunk_log, lm->blk_per_line);
> -
> -	return 0;
> -}
> -
> -static int pblk_lines_init(struct pblk *pblk)
> +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_mgmt *l_mg = &pblk->l_mg;
>   	struct pblk_line_meta *lm = &pblk->lm;
> -	struct pblk_line *line;
> -	void *chunk_log;
>   	unsigned int smeta_len, emeta_len;
> -	long nr_bad_blks = 0, nr_free_blks = 0;
> -	int bb_distance, max_write_ppas, mod;
> -	int i, ret;
> -
> -	pblk->min_write_pgs = geo->sec_per_pl * (geo->sec_size / PAGE_SIZE);
> -	max_write_ppas = pblk->min_write_pgs * geo->all_luns;
> -	pblk->max_write_pgs = min_t(int, max_write_ppas, NVM_MAX_VLBA);
> -	pblk_set_sec_per_write(pblk, pblk->min_write_pgs);
> -
> -	if (pblk->max_write_pgs > PBLK_MAX_REQ_ADDRS) {
> -		pr_err("pblk: vector list too big(%u > %u)\n",
> -				pblk->max_write_pgs, PBLK_MAX_REQ_ADDRS);
> -		return -EINVAL;
> -	}
> -
> -	div_u64_rem(geo->sec_per_chk, pblk->min_write_pgs, &mod);
> -	if (mod) {
> -		pr_err("pblk: bad configuration of sectors/pages\n");
> -		return -EINVAL;
> -	}
> -
> -	l_mg->nr_lines = geo->nr_chks;
> -	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);
> +	int i;
>   
>   	lm->sec_per_line = geo->sec_per_chk * geo->all_luns;
>   	lm->blk_per_line = geo->all_luns;
> @@ -787,58 +833,43 @@ static int pblk_lines_init(struct pblk *pblk)
>   		return -EINVAL;
>   	}
>   
> -	ret = pblk_lines_alloc_metadata(pblk);
> +	return 0;
> +}
> +
> +static int pblk_lines_init(struct pblk *pblk)
> +{
> +	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
> +	struct pblk_line_meta *lm = &pblk->lm;
> +	struct pblk_line *line;
> +	void *chunk_log;
> +	long nr_bad_blks = 0, nr_free_blks = 0;
> +	int i, ret;
> +
> +	ret = pblk_line_meta_init(pblk);
> +	if (ret)
> +		return ret;
> +
> +	ret = pblk_line_mg_init(pblk);
>   	if (ret)
>   		return ret;
>   
> -	l_mg->bb_template = kzalloc(lm->sec_bitmap_len, GFP_KERNEL);
> -	if (!l_mg->bb_template) {
> -		ret = -ENOMEM;
> +	ret = pblk_luns_init(pblk);
> +	if (ret)
>   		goto fail_free_meta;
> -	}
> -
> -	l_mg->bb_aux = kzalloc(lm->sec_bitmap_len, GFP_KERNEL);
> -	if (!l_mg->bb_aux) {
> -		ret = -ENOMEM;
> -		goto fail_free_bb_template;
> -	}
> -
> -	bb_distance = (geo->all_luns) * geo->sec_per_pl;
> -	for (i = 0; i < lm->sec_per_line; i += bb_distance)
> -		bitmap_set(l_mg->bb_template, i, geo->sec_per_pl);
> -
> -	INIT_LIST_HEAD(&l_mg->free_list);
> -	INIT_LIST_HEAD(&l_mg->corrupt_list);
> -	INIT_LIST_HEAD(&l_mg->bad_list);
> -	INIT_LIST_HEAD(&l_mg->gc_full_list);
> -	INIT_LIST_HEAD(&l_mg->gc_high_list);
> -	INIT_LIST_HEAD(&l_mg->gc_mid_list);
> -	INIT_LIST_HEAD(&l_mg->gc_low_list);
> -	INIT_LIST_HEAD(&l_mg->gc_empty_list);
> -
> -	INIT_LIST_HEAD(&l_mg->emeta_list);
> -
> -	l_mg->gc_lists[0] = &l_mg->gc_high_list;
> -	l_mg->gc_lists[1] = &l_mg->gc_mid_list;
> -	l_mg->gc_lists[2] = &l_mg->gc_low_list;
> -
> -	spin_lock_init(&l_mg->free_lock);
> -	spin_lock_init(&l_mg->close_lock);
> -	spin_lock_init(&l_mg->gc_lock);
> -
> -	pblk->lines = kcalloc(l_mg->nr_lines, sizeof(struct pblk_line),
> -								GFP_KERNEL);
> -	if (!pblk->lines) {
> -		ret = -ENOMEM;
> -		goto fail_free_bb_aux;
> -	}
>   
>   	chunk_log = pblk_bb_get_log(pblk);
>   	if (IS_ERR(chunk_log)) {
>   		pr_err("pblk: could not get bad block log (%lu)\n",
>   							PTR_ERR(chunk_log));
>   		ret = PTR_ERR(chunk_log);
> -		goto fail_free_lines;
> +		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_log;
>   	}
>   
>   	for (i = 0; i < l_mg->nr_lines; i++) {
> @@ -856,7 +887,7 @@ static int pblk_lines_init(struct pblk *pblk)
>   
>   		ret = pblk_setup_line_meta(pblk, line, chunk_log, &nr_bad_blks);
>   		if (ret)
> -			goto fail_free_chunk_log;
> +			goto fail_free_lines;
>   
>   		chk_in_line = lm->blk_per_line - nr_bad_blks;
>   		if (nr_bad_blks < 0 || nr_bad_blks > lm->blk_per_line ||
> @@ -878,16 +909,14 @@ static int pblk_lines_init(struct pblk *pblk)
>   	kfree(chunk_log);
>   	return 0;
>   
> -fail_free_chunk_log:
> -	kfree(chunk_log);
> +fail_free_lines:
>   	while (--i >= 0)
>   		pblk_line_meta_free(&pblk->lines[i]);
> -fail_free_lines:
>   	kfree(pblk->lines);
> -fail_free_bb_aux:
> -	kfree(l_mg->bb_aux);
> -fail_free_bb_template:
> -	kfree(l_mg->bb_template);
> +fail_free_chunk_log:
> +	kfree(chunk_log);
> +fail_free_luns:
> +	kfree(pblk->luns);
>   fail_free_meta:
>   	pblk_line_mg_free(pblk);
>   
> @@ -930,12 +959,10 @@ static void pblk_writer_stop(struct pblk *pblk)
>   
>   static void pblk_free(struct pblk *pblk)
>   {
> -	pblk_luns_free(pblk);
>   	pblk_lines_free(pblk);
> -	kfree(pblk->pad_dist);
> -	pblk_line_mg_free(pblk);
> -	pblk_core_free(pblk);
>   	pblk_l2p_free(pblk);
> +	pblk_rwb_free(pblk);
> +	pblk_core_free(pblk);
>   
>   	kfree(pblk);
>   }
> @@ -1000,19 +1027,6 @@ static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
>   	spin_lock_init(&pblk->trans_lock);
>   	spin_lock_init(&pblk->lock);
>   
> -	if (flags & NVM_TARGET_FACTORY)
> -		pblk_setup_uuid(pblk);
> -
> -	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;
> -
>   #ifdef CONFIG_NVM_DEBUG
>   	atomic_long_set(&pblk->inflight_writes, 0);
>   	atomic_long_set(&pblk->padded_writes, 0);
> @@ -1036,48 +1050,35 @@ static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
>   	atomic_long_set(&pblk->write_failed, 0);
>   	atomic_long_set(&pblk->erase_failed, 0);
>   
> -	ret = pblk_luns_init(pblk, dev->luns);
> -	if (ret) {
> -		pr_err("pblk: could not initialize luns\n");
> -		goto fail;
> -	}
> -
> -	ret = pblk_lines_init(pblk);
> -	if (ret) {
> -		pr_err("pblk: could not initialize lines\n");
> -		goto fail_free_luns;
> -	}
> -
> -	pblk->pad_dist = kzalloc((pblk->min_write_pgs - 1) * sizeof(atomic64_t),
> -				 GFP_KERNEL);
> -	if (!pblk->pad_dist) {
> -		ret = -ENOMEM;
> -		goto fail_free_line_meta;
> -	}
> -
>   	ret = pblk_core_init(pblk);
>   	if (ret) {
>   		pr_err("pblk: could not initialize core\n");
> -		goto fail_free_pad_dist;
> +		goto fail;
>   	}
>   
> -	ret = pblk_l2p_init(pblk);
> +	ret = pblk_lines_init(pblk);
>   	if (ret) {
> -		pr_err("pblk: could not initialize maps\n");
> +		pr_err("pblk: could not initialize lines\n");
>   		goto fail_free_core;
>   	}
>   
> -	ret = pblk_lines_configure(pblk, flags);
> +	ret = pblk_rwb_init(pblk);
>   	if (ret) {
> -		pr_err("pblk: could not configure lines\n");
> -		goto fail_free_l2p;
> +		pr_err("pblk: could not initialize write buffer\n");
> +		goto fail_free_lines;
> +	}
> +
> +	ret = pblk_l2p_init(pblk, flags & NVM_TARGET_FACTORY);
> +	if (ret) {
> +		pr_err("pblk: could not initialize maps\n");
> +		goto fail_free_rwb;
>   	}
>   
>   	ret = pblk_writer_init(pblk);
>   	if (ret) {
>   		if (ret != -EINTR)
>   			pr_err("pblk: could not initialize write thread\n");
> -		goto fail_free_lines;
> +		goto fail_free_l2p;
>   	}
>   
>   	ret = pblk_gc_init(pblk);
> @@ -1112,18 +1113,14 @@ static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
>   
>   fail_stop_writer:
>   	pblk_writer_stop(pblk);
> -fail_free_lines:
> -	pblk_lines_free(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_free_pad_dist:
> -	kfree(pblk->pad_dist);
> -fail_free_line_meta:
> -	pblk_line_mg_free(pblk);
> -fail_free_luns:
> -	pblk_luns_free(pblk);
>   fail:
>   	kfree(pblk);
>   	return ERR_PTR(ret);
> 

Thanks. I'm not able to squash it without conflict. Is it based on 
for-4.17/core?