[PATCH 1/3] lightnvm: submit erases using the I/O path

[PATCH 1/3] lightnvm: submit erases using the I/O path

[Javier González]

Until now erases has been submitted as synchronous commands through a
dedicated erase function. In order to allow targets implementing
asynchronous erases, refactor the erase path so that it uses the normal
async I/O submission path. If a target requires sync I/O, it can
implement it internally. Also, adapt rrpc to use the new erase path.

Signed-off-by: Javier González <javier@cnexlabs.com>
---
 drivers/lightnvm/core.c      | 29 --------------------
 drivers/lightnvm/rrpc.c      | 64 ++++++++++++++++++++++++++++++++++++++++++--
 drivers/nvme/host/lightnvm.c | 32 +++++++---------------
 include/linux/lightnvm.h     |  6 ++---
 4 files changed, 75 insertions(+), 56 deletions(-)

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index 4f4db99..3a3e91d 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -617,35 +617,6 @@ int nvm_submit_io(struct nvm_tgt_dev *tgt_dev, struct nvm_rq *rqd)
 }
 EXPORT_SYMBOL(nvm_submit_io);
 
-int nvm_erase_blk(struct nvm_tgt_dev *tgt_dev, struct ppa_addr *ppas, int flags)
-{
-	struct nvm_dev *dev = tgt_dev->parent;
-	struct nvm_rq rqd;
-	int ret;
-
-	if (!dev->ops->erase_block)
-		return 0;
-
-	nvm_map_to_dev(tgt_dev, ppas);
-
-	memset(&rqd, 0, sizeof(struct nvm_rq));
-
-	ret = nvm_set_rqd_ppalist(dev, &rqd, ppas, 1, 1);
-	if (ret)
-		return ret;
-
-	nvm_rq_tgt_to_dev(tgt_dev, &rqd);
-
-	rqd.flags = flags;
-
-	ret = dev->ops->erase_block(dev, &rqd);
-
-	nvm_free_rqd_ppalist(dev, &rqd);
-
-	return ret;
-}
-EXPORT_SYMBOL(nvm_erase_blk);
-
 int nvm_get_l2p_tbl(struct nvm_tgt_dev *tgt_dev, u64 slba, u32 nlb,
 		    nvm_l2p_update_fn *update_l2p, void *priv)
 {
diff --git a/drivers/lightnvm/rrpc.c b/drivers/lightnvm/rrpc.c
index e00b1d7..bec8a9f 100644
--- a/drivers/lightnvm/rrpc.c
+++ b/drivers/lightnvm/rrpc.c
@@ -407,6 +407,67 @@ static int rrpc_move_valid_pages(struct rrpc *rrpc, struct rrpc_block *rblk)
 	return 0;
 }
 
+static void rrpc_end_io_sync(struct nvm_rq *rqd)
+{
+	struct completion *waiting = rqd->private;
+
+	complete(waiting);
+}
+
+static int pblk_erase_blk(struct rrpc *rrpc, struct ppa_addr ppa)
+{
+	struct nvm_tgt_dev *dev = rrpc->dev;
+	struct nvm_geo *geo = &dev->geo;
+	int nr_secs = geo->plane_mode;
+	struct nvm_rq *rqd;
+	int ret;
+	int i;
+	DECLARE_COMPLETION_ONSTACK(wait);
+
+	rqd = mempool_alloc(rrpc->rq_pool, GFP_KERNEL);
+	if (!rqd)
+		return -ENOMEM;
+	memset(rqd, 0, sizeof(struct nvm_rq));
+
+	rqd->opcode = NVM_OP_ERASE;
+	rqd->nr_ppas = nr_secs;
+	rqd->bio = NULL;
+	rqd->end_io = rrpc_end_io_sync;
+	rqd->private = &wait;
+
+	if (nr_secs > 1) {
+		rqd->ppa_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
+							&rqd->dma_ppa_list);
+		if (!rqd->ppa_list) {
+			pr_err("rrpc: not able to allocate ppa list\n");
+			ret = -ENOMEM;
+			goto free_rqd;
+		}
+
+		for (i = 0; i < nr_secs; i++) {
+			ppa.g.pl = i;
+			rqd->ppa_list[i] = ppa;
+		}
+	} else {
+		rqd->ppa_addr = ppa;
+		rqd->ppa_addr.g.pl = 0;
+	}
+
+	ret = nvm_submit_io(dev, rqd);
+	if (ret) {
+		pr_err("rrpr: erase I/O submission falied: %d\n", ret);
+		goto free_ppa_list;
+	}
+	wait_for_completion_io(&wait);
+
+free_ppa_list:
+	if (nr_secs > 1)
+		nvm_dev_dma_free(dev->parent, rqd->ppa_list, rqd->dma_ppa_list);
+free_rqd:
+	mempool_free(rqd, rrpc->rq_pool);
+	return 0;
+}
+
 static void rrpc_block_gc(struct work_struct *work)
 {
 	struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
@@ -414,7 +475,6 @@ static void rrpc_block_gc(struct work_struct *work)
 	struct rrpc *rrpc = gcb->rrpc;
 	struct rrpc_block *rblk = gcb->rblk;
 	struct rrpc_lun *rlun = rblk->rlun;
-	struct nvm_tgt_dev *dev = rrpc->dev;
 	struct ppa_addr ppa;
 
 	mempool_free(gcb, rrpc->gcb_pool);
@@ -430,7 +490,7 @@ static void rrpc_block_gc(struct work_struct *work)
 	ppa.g.lun = rlun->bppa.g.lun;
 	ppa.g.blk = rblk->id;
 
-	if (nvm_erase_blk(dev, &ppa, 0))
+	if (pblk_erase_blk(rrpc, ppa))
 		goto put_back;
 
 	rrpc_put_blk(rrpc, rblk);
diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index 21cac85..3c897ab 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -510,12 +510,16 @@ static int nvme_nvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
 	}
 	rq->cmd_flags &= ~REQ_FAILFAST_DRIVER;
 
-	rq->ioprio = bio_prio(bio);
-	if (bio_has_data(bio))
-		rq->nr_phys_segments = bio_phys_segments(q, bio);
-
-	rq->__data_len = bio->bi_iter.bi_size;
-	rq->bio = rq->biotail = bio;
+	if (bio) {
+		rq->ioprio = bio_prio(bio);
+		rq->__data_len = bio->bi_iter.bi_size;
+		rq->bio = rq->biotail = bio;
+		if (bio_has_data(bio))
+			rq->nr_phys_segments = bio_phys_segments(q, bio);
+	} else {
+		rq->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_NORM);
+		rq->__data_len = 0;
+	}
 
 	nvme_nvm_rqtocmd(rq, rqd, ns, cmd);
 
@@ -526,21 +530,6 @@ static int nvme_nvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
 	return 0;
 }
 
-static int nvme_nvm_erase_block(struct nvm_dev *dev, struct nvm_rq *rqd)
-{
-	struct request_queue *q = dev->q;
-	struct nvme_ns *ns = q->queuedata;
-	struct nvme_nvm_command c = {};
-
-	c.erase.opcode = NVM_OP_ERASE;
-	c.erase.nsid = cpu_to_le32(ns->ns_id);
-	c.erase.spba = cpu_to_le64(rqd->ppa_addr.ppa);
-	c.erase.length = cpu_to_le16(rqd->nr_ppas - 1);
-	c.erase.control = cpu_to_le16(rqd->flags);
-
-	return nvme_submit_sync_cmd(q, (struct nvme_command *)&c, NULL, 0);
-}
-
 static void *nvme_nvm_create_dma_pool(struct nvm_dev *nvmdev, char *name)
 {
 	struct nvme_ns *ns = nvmdev->q->queuedata;
@@ -576,7 +565,6 @@ static struct nvm_dev_ops nvme_nvm_dev_ops = {
 	.set_bb_tbl		= nvme_nvm_set_bb_tbl,
 
 	.submit_io		= nvme_nvm_submit_io,
-	.erase_block		= nvme_nvm_erase_block,
 
 	.create_dma_pool	= nvme_nvm_create_dma_pool,
 	.destroy_dma_pool	= nvme_nvm_destroy_dma_pool,
diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
index 17cd454..a75d8c0 100644
--- a/include/linux/lightnvm.h
+++ b/include/linux/lightnvm.h
@@ -13,6 +13,9 @@ enum {
 
 	NVM_IOTYPE_NONE = 0,
 	NVM_IOTYPE_GC = 1,
+
+	NVM_COMMAND_SYNC = 0,
+	NVM_COMMAND_ASYNC = 1,
 };
 
 #define NVM_BLK_BITS (16)
@@ -56,7 +59,6 @@ typedef int (nvm_get_l2p_tbl_fn)(struct nvm_dev *, u64, u32,
 typedef int (nvm_op_bb_tbl_fn)(struct nvm_dev *, struct ppa_addr, u8 *);
 typedef int (nvm_op_set_bb_fn)(struct nvm_dev *, struct ppa_addr *, int, int);
 typedef int (nvm_submit_io_fn)(struct nvm_dev *, struct nvm_rq *);
-typedef int (nvm_erase_blk_fn)(struct nvm_dev *, struct nvm_rq *);
 typedef void *(nvm_create_dma_pool_fn)(struct nvm_dev *, char *);
 typedef void (nvm_destroy_dma_pool_fn)(void *);
 typedef void *(nvm_dev_dma_alloc_fn)(struct nvm_dev *, void *, gfp_t,
@@ -70,7 +72,6 @@ struct nvm_dev_ops {
 	nvm_op_set_bb_fn	*set_bb_tbl;
 
 	nvm_submit_io_fn	*submit_io;
-	nvm_erase_blk_fn	*erase_block;
 
 	nvm_create_dma_pool_fn	*create_dma_pool;
 	nvm_destroy_dma_pool_fn	*destroy_dma_pool;
@@ -475,7 +476,6 @@ extern int nvm_submit_io(struct nvm_tgt_dev *, struct nvm_rq *);
 extern int nvm_set_rqd_ppalist(struct nvm_dev *, struct nvm_rq *,
 					const struct ppa_addr *, int, int);
 extern void nvm_free_rqd_ppalist(struct nvm_dev *, struct nvm_rq *);
-extern int nvm_erase_blk(struct nvm_tgt_dev *, struct ppa_addr *, int);
 extern int nvm_get_l2p_tbl(struct nvm_tgt_dev *, u64, u32, nvm_l2p_update_fn *,
 			   void *);
 extern int nvm_get_area(struct nvm_tgt_dev *, sector_t *, sector_t);
-- 
2.7.4

[PATCH 2/3] lightnvm: allow targets to use sysfs

[Javier González]

In order to register through the sysfs interface, a driver needs to know
its kobject. On a disk structure, this happens when the partition
information is added (device_add_disk), which for lightnvm takes place
after the target has been initialized. This means that on target
initialization, the kboject has not been created yet.

This patch adds a target function to let targets initialize their own
kboject as a child of the disk kobject.

Signed-off-by: Javier González <javier@cnexlabs.com>
---
 drivers/lightnvm/core.c  | 9 +++++++++
 include/linux/lightnvm.h | 5 +++++
 2 files changed, 14 insertions(+)

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index 3a3e91d..8baae61 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -289,6 +289,9 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
 	set_capacity(tdisk, tt->capacity(targetdata));
 	add_disk(tdisk);
 
+	if (tt->sysfs_init && tt->sysfs_init(tdisk))
+		goto err_sysfs;
+
 	t->type = tt;
 	t->disk = tdisk;
 	t->dev = tgt_dev;
@@ -298,6 +301,9 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
 	mutex_unlock(&dev->mlock);
 
 	return 0;
+err_sysfs:
+	if (tt->exit)
+		tt->exit(targetdata);
 err_init:
 	put_disk(tdisk);
 err_queue:
@@ -320,6 +326,9 @@ static void __nvm_remove_target(struct nvm_target *t)
 	del_gendisk(tdisk);
 	blk_cleanup_queue(q);
 
+	if (tt->sysfs_exit)
+		tt->sysfs_exit(tdisk->private_data);
+
 	if (tt->exit)
 		tt->exit(tdisk->private_data);
 
diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
index a75d8c0..11c318e 100644
--- a/include/linux/lightnvm.h
+++ b/include/linux/lightnvm.h
@@ -440,6 +440,7 @@ typedef blk_qc_t (nvm_tgt_make_rq_fn)(struct request_queue *, struct bio *);
 typedef sector_t (nvm_tgt_capacity_fn)(void *);
 typedef void *(nvm_tgt_init_fn)(struct nvm_tgt_dev *, struct gendisk *);
 typedef void (nvm_tgt_exit_fn)(void *);
+typedef int (nvm_tgt_sysfs_init_fn)(struct gendisk *);
 
 struct nvm_tgt_type {
 	const char *name;
@@ -453,6 +454,10 @@ struct nvm_tgt_type {
 	nvm_tgt_init_fn *init;
 	nvm_tgt_exit_fn *exit;
 
+	/* sysfs */
+	nvm_tgt_sysfs_init_fn *sysfs_init;
+	nvm_tgt_exit_fn *sysfs_exit;
+
 	/* For internal use */
 	struct list_head list;
 };
-- 
2.7.4

[PATCH 3/3] lightnvm: Add CRC read error

[Javier González]

Let the host differentiate between a read error and a CRC check error on
the device side.

Signed-off-by: Javier González <javier@cnexlabs.com>
---
 include/linux/lightnvm.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
index 11c318e..51cda67 100644
--- a/include/linux/lightnvm.h
+++ b/include/linux/lightnvm.h
@@ -108,6 +108,7 @@ enum {
 	NVM_RSP_ERR_FAILWRITE	= 0x40ff,
 	NVM_RSP_ERR_EMPTYPAGE	= 0x42ff,
 	NVM_RSP_ERR_FAILECC	= 0x4281,
+	NVM_RSP_ERR_FAILCRC	= 0x4004,
 	NVM_RSP_WARN_HIGHECC	= 0x4700,
 
 	/* Device opcodes */
-- 
2.7.4

Re: [PATCH 3/3] lightnvm: Add CRC read error

[Matias Bjørling]

On 01/26/2017 12:47 PM, Javier González wrote:
> Let the host differentiate between a read error and a CRC check error on
> the device side.
> 
> Signed-off-by: Javier González <javier@cnexlabs.com>
> ---
>  include/linux/lightnvm.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
> index 11c318e..51cda67 100644
> --- a/include/linux/lightnvm.h
> +++ b/include/linux/lightnvm.h
> @@ -108,6 +108,7 @@ enum {
>  	NVM_RSP_ERR_FAILWRITE	= 0x40ff,
>  	NVM_RSP_ERR_EMPTYPAGE	= 0x42ff,
>  	NVM_RSP_ERR_FAILECC	= 0x4281,
> +	NVM_RSP_ERR_FAILCRC	= 0x4004,
>  	NVM_RSP_WARN_HIGHECC	= 0x4700,
>  
>  	/* Device opcodes */
> 

Thanks. Applied.

Re: [PATCH 2/3] lightnvm: allow targets to use sysfs

[Matias Bjørling]

On 01/26/2017 12:47 PM, Javier González wrote:
> In order to register through the sysfs interface, a driver needs to know
> its kobject. On a disk structure, this happens when the partition
> information is added (device_add_disk), which for lightnvm takes place
> after the target has been initialized. This means that on target
> initialization, the kboject has not been created yet.
> 
> This patch adds a target function to let targets initialize their own
> kboject as a child of the disk kobject.
> 
> Signed-off-by: Javier González <javier@cnexlabs.com>
> ---
>  drivers/lightnvm/core.c  | 9 +++++++++
>  include/linux/lightnvm.h | 5 +++++
>  2 files changed, 14 insertions(+)
> 
> diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
> index 3a3e91d..8baae61 100644
> --- a/drivers/lightnvm/core.c
> +++ b/drivers/lightnvm/core.c
> @@ -289,6 +289,9 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
>  	set_capacity(tdisk, tt->capacity(targetdata));
>  	add_disk(tdisk);
>  
> +	if (tt->sysfs_init && tt->sysfs_init(tdisk))
> +		goto err_sysfs;
> +
>  	t->type = tt;
>  	t->disk = tdisk;
>  	t->dev = tgt_dev;
> @@ -298,6 +301,9 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
>  	mutex_unlock(&dev->mlock);
>  
>  	return 0;
> +err_sysfs:
> +	if (tt->exit)
> +		tt->exit(targetdata);
>  err_init:
>  	put_disk(tdisk);
>  err_queue:
> @@ -320,6 +326,9 @@ static void __nvm_remove_target(struct nvm_target *t)
>  	del_gendisk(tdisk);
>  	blk_cleanup_queue(q);
>  
> +	if (tt->sysfs_exit)
> +		tt->sysfs_exit(tdisk->private_data);

Lets pass gendisk here.

> +
>  	if (tt->exit)
>  		tt->exit(tdisk->private_data);
>  
> diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
> index a75d8c0..11c318e 100644
> --- a/include/linux/lightnvm.h
> +++ b/include/linux/lightnvm.h
> @@ -440,6 +440,7 @@ typedef blk_qc_t (nvm_tgt_make_rq_fn)(struct request_queue *, struct bio *);
>  typedef sector_t (nvm_tgt_capacity_fn)(void *);
>  typedef void *(nvm_tgt_init_fn)(struct nvm_tgt_dev *, struct gendisk *);
>  typedef void (nvm_tgt_exit_fn)(void *);
> +typedef int (nvm_tgt_sysfs_init_fn)(struct gendisk *);
>  
>  struct nvm_tgt_type {
>  	const char *name;
> @@ -453,6 +454,10 @@ struct nvm_tgt_type {
>  	nvm_tgt_init_fn *init;
>  	nvm_tgt_exit_fn *exit;
>  
> +	/* sysfs */
> +	nvm_tgt_sysfs_init_fn *sysfs_init;
> +	nvm_tgt_exit_fn *sysfs_exit;

Might as well typedef an exit for synergy.

> +
>  	/* For internal use */
>  	struct list_head list;
>  };
> 

Thanks. Applied. I have made the above modifications.

Re: [PATCH 1/3] lightnvm: submit erases using the I/O path

[Matias Bjørling]

On 01/26/2017 12:47 PM, Javier González wrote:
> Until now erases has been submitted as synchronous commands through a
> dedicated erase function. In order to allow targets implementing
> asynchronous erases, refactor the erase path so that it uses the normal
> async I/O submission path. If a target requires sync I/O, it can
> implement it internally. Also, adapt rrpc to use the new erase path.
> 
> Signed-off-by: Javier González <javier@cnexlabs.com>
> ---
>  drivers/lightnvm/core.c      | 29 --------------------
>  drivers/lightnvm/rrpc.c      | 64 ++++++++++++++++++++++++++++++++++++++++++--
>  drivers/nvme/host/lightnvm.c | 32 +++++++---------------
>  include/linux/lightnvm.h     |  6 ++---
>  4 files changed, 75 insertions(+), 56 deletions(-)
> 
> diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
> index 4f4db99..3a3e91d 100644
> --- a/drivers/lightnvm/core.c
> +++ b/drivers/lightnvm/core.c
> @@ -617,35 +617,6 @@ int nvm_submit_io(struct nvm_tgt_dev *tgt_dev, struct nvm_rq *rqd)
>  }
>  EXPORT_SYMBOL(nvm_submit_io);
>  
> -int nvm_erase_blk(struct nvm_tgt_dev *tgt_dev, struct ppa_addr *ppas, int flags)
> -{
> -	struct nvm_dev *dev = tgt_dev->parent;
> -	struct nvm_rq rqd;
> -	int ret;
> -
> -	if (!dev->ops->erase_block)
> -		return 0;
> -
> -	nvm_map_to_dev(tgt_dev, ppas);
> -
> -	memset(&rqd, 0, sizeof(struct nvm_rq));
> -
> -	ret = nvm_set_rqd_ppalist(dev, &rqd, ppas, 1, 1);
> -	if (ret)
> -		return ret;
> -
> -	nvm_rq_tgt_to_dev(tgt_dev, &rqd);
> -
> -	rqd.flags = flags;
> -
> -	ret = dev->ops->erase_block(dev, &rqd);
> -
> -	nvm_free_rqd_ppalist(dev, &rqd);
> -
> -	return ret;
> -}
> -EXPORT_SYMBOL(nvm_erase_blk);
> -
>  int nvm_get_l2p_tbl(struct nvm_tgt_dev *tgt_dev, u64 slba, u32 nlb,
>  		    nvm_l2p_update_fn *update_l2p, void *priv)
>  {
> diff --git a/drivers/lightnvm/rrpc.c b/drivers/lightnvm/rrpc.c
> index e00b1d7..bec8a9f 100644
> --- a/drivers/lightnvm/rrpc.c
> +++ b/drivers/lightnvm/rrpc.c
> @@ -407,6 +407,67 @@ static int rrpc_move_valid_pages(struct rrpc *rrpc, struct rrpc_block *rblk)
>  	return 0;
>  }
>  
> +static void rrpc_end_io_sync(struct nvm_rq *rqd)
> +{
> +	struct completion *waiting = rqd->private;
> +
> +	complete(waiting);
> +}
> +
> +static int pblk_erase_blk(struct rrpc *rrpc, struct ppa_addr ppa)

Extend the interface to take a list of PPAs.

> +{
> +	struct nvm_tgt_dev *dev = rrpc->dev;
> +	struct nvm_geo *geo = &dev->geo;
> +	int nr_secs = geo->plane_mode;
> +	struct nvm_rq *rqd;
> +	int ret;
> +	int i;
> +	DECLARE_COMPLETION_ONSTACK(wait);
> +
> +	rqd = mempool_alloc(rrpc->rq_pool, GFP_KERNEL);
> +	if (!rqd)
> +		return -ENOMEM;
> +	memset(rqd, 0, sizeof(struct nvm_rq));
> +
> +	rqd->opcode = NVM_OP_ERASE;
> +	rqd->nr_ppas = nr_secs;
> +	rqd->bio = NULL;
> +	rqd->end_io = rrpc_end_io_sync;
> +	rqd->private = &wait;
> +
> +	if (nr_secs > 1) {
> +		rqd->ppa_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
> +							&rqd->dma_ppa_list);
> +		if (!rqd->ppa_list) {
> +			pr_err("rrpc: not able to allocate ppa list\n");
> +			ret = -ENOMEM;
> +			goto free_rqd;
> +		}
> +
> +		for (i = 0; i < nr_secs; i++) {
> +			ppa.g.pl = i;
> +			rqd->ppa_list[i] = ppa;
> +		}
> +	} else {
> +		rqd->ppa_addr = ppa;
> +		rqd->ppa_addr.g.pl = 0;
> +	}
> +

nvm_set_rqd_ppalist() can be used instead of the above. Also, this code
should properly not be in this patch, but part of pblk.

> +	ret = nvm_submit_io(dev, rqd);
> +	if (ret) {
> +		pr_err("rrpr: erase I/O submission falied: %d\n", ret);
> +		goto free_ppa_list;
> +	}
> +	wait_for_completion_io(&wait);
> +
> +free_ppa_list:
> +	if (nr_secs > 1)
> +		nvm_dev_dma_free(dev->parent, rqd->ppa_list, rqd->dma_ppa_list);
> +free_rqd:
> +	mempool_free(rqd, rrpc->rq_pool);
> +	return 0;
> +}
> +
>  static void rrpc_block_gc(struct work_struct *work)
>  {
>  	struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
> @@ -414,7 +475,6 @@ static void rrpc_block_gc(struct work_struct *work)
>  	struct rrpc *rrpc = gcb->rrpc;
>  	struct rrpc_block *rblk = gcb->rblk;
>  	struct rrpc_lun *rlun = rblk->rlun;
> -	struct nvm_tgt_dev *dev = rrpc->dev;
>  	struct ppa_addr ppa;
>  
>  	mempool_free(gcb, rrpc->gcb_pool);
> @@ -430,7 +490,7 @@ static void rrpc_block_gc(struct work_struct *work)
>  	ppa.g.lun = rlun->bppa.g.lun;
>  	ppa.g.blk = rblk->id;
>  
> -	if (nvm_erase_blk(dev, &ppa, 0))
> +	if (pblk_erase_blk(rrpc, ppa))
>  		goto put_back;
>  
>  	rrpc_put_blk(rrpc, rblk);
> diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
> index 21cac85..3c897ab 100644
> --- a/drivers/nvme/host/lightnvm.c
> +++ b/drivers/nvme/host/lightnvm.c
> @@ -510,12 +510,16 @@ static int nvme_nvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
>  	}
>  	rq->cmd_flags &= ~REQ_FAILFAST_DRIVER;
>  
> -	rq->ioprio = bio_prio(bio);
> -	if (bio_has_data(bio))
> -		rq->nr_phys_segments = bio_phys_segments(q, bio);
> -
> -	rq->__data_len = bio->bi_iter.bi_size;
> -	rq->bio = rq->biotail = bio;
> +	if (bio) {
> +		rq->ioprio = bio_prio(bio);
> +		rq->__data_len = bio->bi_iter.bi_size;
> +		rq->bio = rq->biotail = bio;
> +		if (bio_has_data(bio))
> +			rq->nr_phys_segments = bio_phys_segments(q, bio);
> +	} else {
> +		rq->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_NORM);
> +		rq->__data_len = 0;
> +	}
>  
>  	nvme_nvm_rqtocmd(rq, rqd, ns, cmd);
>  
> @@ -526,21 +530,6 @@ static int nvme_nvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
>  	return 0;
>  }
>  
> -static int nvme_nvm_erase_block(struct nvm_dev *dev, struct nvm_rq *rqd)
> -{
> -	struct request_queue *q = dev->q;
> -	struct nvme_ns *ns = q->queuedata;
> -	struct nvme_nvm_command c = {};
> -
> -	c.erase.opcode = NVM_OP_ERASE;
> -	c.erase.nsid = cpu_to_le32(ns->ns_id);
> -	c.erase.spba = cpu_to_le64(rqd->ppa_addr.ppa);
> -	c.erase.length = cpu_to_le16(rqd->nr_ppas - 1);
> -	c.erase.control = cpu_to_le16(rqd->flags);
> -
> -	return nvme_submit_sync_cmd(q, (struct nvme_command *)&c, NULL, 0);
> -}
> -
>  static void *nvme_nvm_create_dma_pool(struct nvm_dev *nvmdev, char *name)
>  {
>  	struct nvme_ns *ns = nvmdev->q->queuedata;
> @@ -576,7 +565,6 @@ static struct nvm_dev_ops nvme_nvm_dev_ops = {
>  	.set_bb_tbl		= nvme_nvm_set_bb_tbl,
>  
>  	.submit_io		= nvme_nvm_submit_io,
> -	.erase_block		= nvme_nvm_erase_block,
>  
>  	.create_dma_pool	= nvme_nvm_create_dma_pool,
>  	.destroy_dma_pool	= nvme_nvm_destroy_dma_pool,
> diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
> index 17cd454..a75d8c0 100644
> --- a/include/linux/lightnvm.h
> +++ b/include/linux/lightnvm.h
> @@ -13,6 +13,9 @@ enum {
>  
>  	NVM_IOTYPE_NONE = 0,
>  	NVM_IOTYPE_GC = 1,
> +
> +	NVM_COMMAND_SYNC = 0,
> +	NVM_COMMAND_ASYNC = 1,

We may just use the values (i.e., pass "sync" variable".)

>  };
>  
>  #define NVM_BLK_BITS (16)
> @@ -56,7 +59,6 @@ typedef int (nvm_get_l2p_tbl_fn)(struct nvm_dev *, u64, u32,
>  typedef int (nvm_op_bb_tbl_fn)(struct nvm_dev *, struct ppa_addr, u8 *);
>  typedef int (nvm_op_set_bb_fn)(struct nvm_dev *, struct ppa_addr *, int, int);
>  typedef int (nvm_submit_io_fn)(struct nvm_dev *, struct nvm_rq *);
> -typedef int (nvm_erase_blk_fn)(struct nvm_dev *, struct nvm_rq *);
>  typedef void *(nvm_create_dma_pool_fn)(struct nvm_dev *, char *);
>  typedef void (nvm_destroy_dma_pool_fn)(void *);
>  typedef void *(nvm_dev_dma_alloc_fn)(struct nvm_dev *, void *, gfp_t,
> @@ -70,7 +72,6 @@ struct nvm_dev_ops {
>  	nvm_op_set_bb_fn	*set_bb_tbl;
>  
>  	nvm_submit_io_fn	*submit_io;
> -	nvm_erase_blk_fn	*erase_block;
>  
>  	nvm_create_dma_pool_fn	*create_dma_pool;
>  	nvm_destroy_dma_pool_fn	*destroy_dma_pool;
> @@ -475,7 +476,6 @@ extern int nvm_submit_io(struct nvm_tgt_dev *, struct nvm_rq *);
>  extern int nvm_set_rqd_ppalist(struct nvm_dev *, struct nvm_rq *,
>  					const struct ppa_addr *, int, int);
>  extern void nvm_free_rqd_ppalist(struct nvm_dev *, struct nvm_rq *);
> -extern int nvm_erase_blk(struct nvm_tgt_dev *, struct ppa_addr *, int);
>  extern int nvm_get_l2p_tbl(struct nvm_tgt_dev *, u64, u32, nvm_l2p_update_fn *,
>  			   void *);
>  extern int nvm_get_area(struct nvm_tgt_dev *, sector_t *, sector_t);
>