Date:	Fri, 5 Feb 2016 12:58:45 +0100
From:	Matias Bjørling <mb@...htnvm.io>
To:	Wenwei Tao <ww.tao0320@...il.com>
Cc:	linux-kernel@...r.kernel.org, linux-block@...r.kernel.org
Subject: Re: [PATCH v3 1/3] lightnvm: specify target's logical address area

On 02/04/2016 12:34 PM, Wenwei Tao wrote:
> We can create more than one target on a lightnvm
> device by specifying its begin lun and end lun.
> 
> But only specify the physical address area is not
> enough, we need to get the corresponding non-
> intersection logical address area division from
> the backend device's logcial address space.
> Otherwise the targets on the device might use
> the same logical addresses cause incorrect
> information in the device's l2p table.
> 
> Signed-off-by: Wenwei Tao <ww.tao0320@...il.com>
> ---
> Changes since v2:
> -rebase on for-next branch
> -make the list increase by area->begin
> 
> Changes since v1:
> -rename some variables
> -add parentheses for clarify
> -make gennvm_get_area return int, and add one more sector_t* parameter
> to pass the begin sector of the corresponding target
> -rebase to v4.5-rc1
> 
>  drivers/lightnvm/core.c   |  1 +
>  drivers/lightnvm/gennvm.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++
>  drivers/lightnvm/gennvm.h |  6 +++++
>  drivers/lightnvm/rrpc.c   | 36 +++++++++++++++++++++++---
>  drivers/lightnvm/rrpc.h   |  1 +
>  include/linux/lightnvm.h  |  8 ++++++
>  6 files changed, 114 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
> index 5471cc5..93c035b 100644
> --- a/drivers/lightnvm/core.c
> +++ b/drivers/lightnvm/core.c
> @@ -466,6 +466,7 @@ static int nvm_core_init(struct nvm_dev *dev)
>  	dev->total_secs = dev->nr_luns * dev->sec_per_lun;
>  	INIT_LIST_HEAD(&dev->online_targets);
>  	mutex_init(&dev->mlock);
> +	spin_lock_init(&dev->lock);
>  
>  	return 0;
>  }
> diff --git a/drivers/lightnvm/gennvm.c b/drivers/lightnvm/gennvm.c
> index d65ec36..fba3fbd 100644
> --- a/drivers/lightnvm/gennvm.c
> +++ b/drivers/lightnvm/gennvm.c
> @@ -20,6 +20,66 @@
>  
>  #include "gennvm.h"
>  
> +static int gennvm_get_area(struct nvm_dev *dev, sector_t *begin_sect,
> +							sector_t size)
> +{
> +	struct gen_nvm *gn = dev->mp;
> +	struct gennvm_area *area, *prev, *next;
> +	sector_t begin = 0;
> +	sector_t max_sectors = (dev->sec_size * dev->total_secs) >> 9;
> +
> +	if (size > max_sectors)
> +		return -EINVAL;
> +	area = kmalloc(sizeof(struct gennvm_area), GFP_KERNEL);
> +	if (!area)
> +		return -ENOMEM;
> +
> +	prev = NULL;
> +
> +	spin_lock(&dev->lock);
> +	list_for_each_entry(next, &gn->area_list, list) {
> +		if (begin + size > next->begin) {
> +			begin = next->end;
> +			prev = next;
> +			continue;
> +		}
> +		break;
> +	}
> +
> +	if ((begin + size) > max_sectors) {
> +		spin_unlock(&dev->lock);
> +		kfree(area);
> +		return -EINVAL;
> +	}
> +
> +	area->begin = *begin_sect =  begin;
> +	area->end = begin + size;
> +	if (prev)
> +		list_add(&area->list, &prev->list);
> +	else
> +		list_add(&area->list, &gn->area_list);
> +	spin_unlock(&dev->lock);
> +	return 0;
> +}
> +
> +static void gennvm_put_area(struct nvm_dev *dev, sector_t begin)
> +{
> +	struct gen_nvm *gn = dev->mp;
> +	struct gennvm_area *area;
> +
> +	spin_lock(&dev->lock);
> +	list_for_each_entry(area, &gn->area_list, list) {
> +		if (area->begin != begin)
> +			continue;
> +
> +		list_del(&area->list);
> +		spin_unlock(&dev->lock);
> +		kfree(area);
> +		return;
> +	}
> +	spin_unlock(&dev->lock);
> +}
> +
>  static void gennvm_blocks_free(struct nvm_dev *dev)
>  {
>  	struct gen_nvm *gn = dev->mp;
> @@ -229,6 +289,7 @@ static int gennvm_register(struct nvm_dev *dev)
>  
>  	gn->dev = dev;
>  	gn->nr_luns = dev->nr_luns;
> +	INIT_LIST_HEAD(&gn->area_list);
>  	dev->mp = gn;
>  
>  	ret = gennvm_luns_init(dev, gn);
> @@ -465,6 +526,10 @@ static struct nvmm_type gennvm = {
>  
>  	.get_lun		= gennvm_get_lun,
>  	.lun_info_print		= gennvm_lun_info_print,
> +
> +	.get_area		= gennvm_get_area,
> +	.put_area		= gennvm_put_area,
> +
>  };
>  
>  static int __init gennvm_module_init(void)
> diff --git a/drivers/lightnvm/gennvm.h b/drivers/lightnvm/gennvm.h
> index 9c24b5b..04d7c23 100644
> --- a/drivers/lightnvm/gennvm.h
> +++ b/drivers/lightnvm/gennvm.h
> @@ -39,8 +39,14 @@ struct gen_nvm {
>  
>  	int nr_luns;
>  	struct gen_lun *luns;
> +	struct list_head area_list;
>  };
>  
> +struct gennvm_area {
> +	struct list_head list;
> +	sector_t begin;
> +	sector_t end;	/* end is excluded */
> +};
>  #define gennvm_for_each_lun(bm, lun, i) \
>  		for ((i) = 0, lun = &(bm)->luns[0]; \
>  			(i) < (bm)->nr_luns; (i)++, lun = &(bm)->luns[(i)])
> diff --git a/drivers/lightnvm/rrpc.c b/drivers/lightnvm/rrpc.c
> index c4d0b04..6ce5f73 100644
> --- a/drivers/lightnvm/rrpc.c
> +++ b/drivers/lightnvm/rrpc.c
> @@ -1038,8 +1038,11 @@ static int rrpc_map_init(struct rrpc *rrpc)
>  {
>  	struct nvm_dev *dev = rrpc->dev;
>  	sector_t i;
> +	u64 slba;
>  	int ret;
>  
> +	slba = rrpc->soffset >> (ilog2(dev->sec_size) - 9);
> +
>  	rrpc->trans_map = vzalloc(sizeof(struct rrpc_addr) * rrpc->nr_sects);
>  	if (!rrpc->trans_map)
>  		return -ENOMEM;
> @@ -1061,8 +1064,8 @@ static int rrpc_map_init(struct rrpc *rrpc)
>  		return 0;
>  
>  	/* Bring up the mapping table from device */
> -	ret = dev->ops->get_l2p_tbl(dev, 0, dev->total_secs, rrpc_l2p_update,
> -									rrpc);
> +	ret = dev->ops->get_l2p_tbl(dev, slba, rrpc->nr_sects,
> +			rrpc_l2p_update, rrpc);
>  	if (ret) {
>  		pr_err("nvm: rrpc: could not read L2P table.\n");
>  		return -EINVAL;
> @@ -1071,7 +1074,6 @@ static int rrpc_map_init(struct rrpc *rrpc)
>  	return 0;
>  }
>  
> -
>  /* Minimum pages needed within a lun */
>  #define PAGE_POOL_SIZE 16
>  #define ADDR_POOL_SIZE 64
> @@ -1185,12 +1187,32 @@ err:
>  	return -ENOMEM;
>  }
>  
> +/* returns 0 on success and stores the beginning address in *begin */
> +static int rrpc_area_init(struct rrpc *rrpc, sector_t *begin)
> +{
> +	struct nvm_dev *dev = rrpc->dev;
> +	struct nvmm_type *mt = dev->mt;
> +	sector_t size = rrpc->nr_sects * dev->sec_size;
> +
> +	size >>= 9;
> +	return mt->get_area(dev, begin, size);
> +}
> +
> +static void rrpc_area_free(struct rrpc *rrpc)
> +{
> +	struct nvm_dev *dev = rrpc->dev;
> +	struct nvmm_type *mt = dev->mt;
> +
> +	mt->put_area(dev, rrpc->soffset);
> +}
> +
>  static void rrpc_free(struct rrpc *rrpc)
>  {
>  	rrpc_gc_free(rrpc);
>  	rrpc_map_free(rrpc);
>  	rrpc_core_free(rrpc);
>  	rrpc_luns_free(rrpc);
> +	rrpc_area_free(rrpc);
>  
>  	kfree(rrpc);
>  }
> @@ -1311,6 +1333,7 @@ static void *rrpc_init(struct nvm_dev *dev, struct gendisk *tdisk,
>  	struct request_queue *bqueue = dev->q;
>  	struct request_queue *tqueue = tdisk->queue;
>  	struct rrpc *rrpc;
> +	sector_t soffset;
>  	int ret;
>  
>  	if (!(dev->identity.dom & NVM_RSP_L2P)) {
> @@ -1336,6 +1359,13 @@ static void *rrpc_init(struct nvm_dev *dev, struct gendisk *tdisk,
>  	/* simple round-robin strategy */
>  	atomic_set(&rrpc->next_lun, -1);
>  
> +	ret = rrpc_area_init(rrpc, &soffset);
> +	if (ret < 0) {
> +		pr_err("nvm: rrpc: could not initialize area\n");
> +		return ERR_PTR(ret);
> +	}
> +	rrpc->soffset = soffset;
> +
>  	ret = rrpc_luns_init(rrpc, lun_begin, lun_end);
>  	if (ret) {
>  		pr_err("nvm: rrpc: could not initialize luns\n");
> diff --git a/drivers/lightnvm/rrpc.h b/drivers/lightnvm/rrpc.h
> index dfca5c4..6148b14 100644
> --- a/drivers/lightnvm/rrpc.h
> +++ b/drivers/lightnvm/rrpc.h
> @@ -97,6 +97,7 @@ struct rrpc {
>  	struct nvm_dev *dev;
>  	struct gendisk *disk;
>  
> +	sector_t soffset; /* logical sector offset */
>  	u64 poffset; /* physical page offset */
>  	int lun_offset;
>  
> diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
> index b94f2d5..ce58ad5 100644
> --- a/include/linux/lightnvm.h
> +++ b/include/linux/lightnvm.h
> @@ -351,6 +351,7 @@ struct nvm_dev {
>  	char name[DISK_NAME_LEN];
>  
>  	struct mutex mlock;
> +	spinlock_t lock;
>  };
>  
>  static inline struct ppa_addr generic_to_dev_addr(struct nvm_dev *dev,
> @@ -463,6 +464,9 @@ typedef int (nvmm_erase_blk_fn)(struct nvm_dev *, struct nvm_block *,
>  typedef struct nvm_lun *(nvmm_get_lun_fn)(struct nvm_dev *, int);
>  typedef void (nvmm_lun_info_print_fn)(struct nvm_dev *);
>  
> +typedef int (nvmm_get_area_fn)(struct nvm_dev *, sector_t *, sector_t);
> +typedef void (nvmm_put_area_fn)(struct nvm_dev *, sector_t);
> +
>  struct nvmm_type {
>  	const char *name;
>  	unsigned int version[3];
> @@ -487,6 +491,10 @@ struct nvmm_type {
>  
>  	/* Statistics */
>  	nvmm_lun_info_print_fn *lun_info_print;
> +
> +	nvmm_get_area_fn *get_area;
> +	nvmm_put_area_fn *put_area;
> +
>  	struct list_head list;
>  };
>  
> 

Thanks, applied for 4.6. I made some small style changes.

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