Re: [PATCH v2 1/2] lightnvm: specify target's logical address area

["Matias Bjørling" <mb@lightnvm.io>]

On 01/26/2016 01:33 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@gmail.com>
> ---
> Changes since v1:
> - rename some variables
> - add parentheses for clarity
> - 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 | 59 +++++++++++++++++++++++++++++++++++++++++++++++
>  drivers/lightnvm/gennvm.h |  6 +++++
>  drivers/lightnvm/rrpc.c   | 45 +++++++++++++++++++++++++++++++++---
>  drivers/lightnvm/rrpc.h   |  1 +
>  include/linux/lightnvm.h  |  8 +++++++
>  6 files changed, 117 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
> index 33224cb..27a59e8 100644
> --- a/drivers/lightnvm/core.c
> +++ b/drivers/lightnvm/core.c
> @@ -470,6 +470,7 @@ static int nvm_core_init(struct nvm_dev *dev)
>  	dev->total_pages = dev->total_blocks * dev->pgs_per_blk;
>  	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 7fb725b..34ea4ff 100644
> --- a/drivers/lightnvm/gennvm.c
> +++ b/drivers/lightnvm/gennvm.c
> @@ -20,6 +20,60 @@
>  
>  #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;
> +	sector_t begin = 0;
> +	int page_size = dev->sec_size * dev->sec_per_pg;
> +	sector_t max_sectors = (page_size * dev->total_pages) >> 9;
> +
> +	if (size > max_sectors)
> +		return -EINVAL;
> +	area = kmalloc(sizeof(struct gennvm_area), GFP_KERNEL);
> +	if (!area)
> +		return -ENOMEM;
> +
> +	spin_lock(&dev->lock);
> +	list_for_each_entry(prev, &gn->area_list, list) {
> +		if (begin + size > prev->begin) {
> +			begin = prev->end;
> +			continue;
> +		}
> +		break;
> +	}
> +
> +	if ((begin + size) > max_sectors) {
> +		spin_unlock(&dev->lock);
> +		kfree(area);
> +		return -EINVAL;
> +	}
> +
> +	area->begin = *begin_sect =  begin;
> +	area->end = begin + size;
> +	list_add(&area->list, &prev->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) {
> +			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;
> @@ -230,6 +284,7 @@ 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);
> @@ -466,6 +521,10 @@ 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 d8c7595..c8c27f9 100644
> --- a/drivers/lightnvm/rrpc.c
> +++ b/drivers/lightnvm/rrpc.c
> @@ -1042,7 +1042,18 @@ static int rrpc_map_init(struct rrpc *rrpc)
>  {
>  	struct nvm_dev *dev = rrpc->dev;
>  	sector_t i;
> -	int ret;
> +	u64 slba;
> +	int ret, page_size;
> +	int page_shfit, nr_pages;

Did you mean page_shift here?