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

Wenwei Tao
2016-01-27T12:47:29Z

2016-01-27 17:36 GMT+08:00 Matias Bjørling <mb@lightnvm.io>:
> On 01/27/2016 07:06 AM, Wenwei Tao wrote:
>> Thanks.
>>
>> 2016-01-27 13:52 GMT+08:00 Matias Bjørling <mb@lightnvm.io>:
>>> On 01/27/2016 03:21 AM, Wenwei Tao wrote:
>>>>
>>>> Yes, It's a spelling mistake, will correct it in next version.
>>>
>>>
>>> I can fix it in the version I apply. No problem.
>
> Hi Wenwei,
>
> I've changed it to this. Clean up the variables a bit. Is that ok with you?
>
> Thanks
>
> 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..6e2685d 100644
> --- a/drivers/lightnvm/gennvm.c
> +++ b/drivers/lightnvm/gennvm.c
> @@ -20,6 +20,63 @@
>
> #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;
> + int page_size = dev->sec_size * dev->sec_per_pg;
> + sector_t begin = 0;
> + 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);

I think I have made a mistake here. Insert the new area after prev
will not make the list increase by area->begin. And prev is not
trustable
when out of the loop, it may point to list_entry((head)->next,
typeof(*pos), member). Below is changed code:

+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;
+ 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;
+
+ 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;
+}

> + 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;
> @@ -230,6 +287,7 @@ 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 +524,10 @@ 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 e2710da..20afe1c 100644
> --- a/drivers/lightnvm/rrpc.c
> +++ b/drivers/lightnvm/rrpc.c
> @@ -1039,7 +1039,11 @@ 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;
> +
> + page_size = dev->sec_per_pg * dev->sec_size;
> + slba = rrpc->soffset >> (ilog2(page_size) - 9);
>
> rrpc->trans_map = vzalloc(sizeof(struct rrpc_addr) * rrpc->nr_pages);
> if (!rrpc->trans_map)
> @@ -1062,8 +1066,8 @@ 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_pages,
> - rrpc_l2p_update, rrpc);
> + ret = dev->ops->get_l2p_tbl(dev, slba, rrpc->nr_pages, rrpc_l2p_update,
> + rrpc);

In rrpc_luns_init, rrpc->nr_pages seems to be the target's sector
number and previously dev->total_pages is used, dev->total_pages is
the nvm device page number, so I am a little confusing here.

> if (ret) {
> pr_err("nvm: rrpc: could not read L2P table.\n");
> return -EINVAL;
> @@ -1072,7 +1076,6 @@ 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
> @@ -1186,12 +1189,32 @@ 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_luns * dev->sec_per_lun * 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);
> }
> @@ -1312,6 +1335,7 @@ 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)) {
> @@ -1337,6 +1361,13 @@ 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 ef13ac7..9380c68 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 d675011..18f1bb0 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;
> };
>
>
>
>