On 3/17/21 11:10 PM, Qiaowei Ren wrote:
> From: Jianpeng Ma <jianpeng.ma@xxxxxxxxx>
>
> This patch implements the bch_nvm_alloc_pages() of the buddy.
We need more informative commit log here. E.g. what is the difference
between nvm-pages buddy allocator and current pages buddy allocator.
Thanks.
Coly Li
>
> Signed-off-by: Jianpeng Ma <jianpeng.ma@xxxxxxxxx>
> Co-authored-by: Qiaowei Ren <qiaowei.ren@xxxxxxxxx>
> ---
> drivers/md/bcache/nvm-pages.c | 156 ++++++++++++++++++++++++++++++++++
> drivers/md/bcache/nvm-pages.h | 6 ++
> 2 files changed, 162 insertions(+)
>
> diff --git a/drivers/md/bcache/nvm-pages.c b/drivers/md/bcache/nvm-pages.c
> index 1f99965920a1..c1fefcd27363 100644
> --- a/drivers/md/bcache/nvm-pages.c
> +++ b/drivers/md/bcache/nvm-pages.c
> @@ -75,6 +75,162 @@ static inline void remove_owner_space(struct bch_nvm_namespace *ns,
> bitmap_set(ns->pages_bitmap, pgoff, nr);
> }
>
> +/* If not found, it will create if create == true */
> +static struct bch_nvm_pages_owner_head *find_owner_head(const char *owner_uuid, bool create)
> +{
> + struct bch_owner_list_head *owner_list_head = only_set->owner_list_head;
> + int i;
> +
> + for (i = 0; i < only_set->owner_list_used; i++) {
> + if (!memcmp(owner_uuid, owner_list_head->heads[i].uuid, 16))
> + return &(owner_list_head->heads[i]);
> + }
> +
> + if (create) {
> + int used = only_set->owner_list_used;
> +
> + BUG_ON(only_set->owner_list_size == used);
> + memcpy(owner_list_head->heads[used].uuid, owner_uuid, 16);
> + only_set->owner_list_used++;
> +
> + owner_list_head->used++;
> + return &(owner_list_head->heads[used]);
> + } else
> + return NULL;
> +}
> +
> +static struct bch_nvm_pgalloc_recs *find_empty_pgalloc_recs(void)
> +{
> + unsigned int start;
> + struct bch_nvm_namespace *ns = only_set->nss[0];
> + struct bch_nvm_pgalloc_recs *recs;
> +
> + start = bitmap_find_next_zero_area(ns->pgalloc_recs_bitmap, BCH_MAX_PGALLOC_RECS, 0, 1, 0);
> + if (start > BCH_MAX_PGALLOC_RECS) {
> + pr_info("no free struct bch_nvm_pgalloc_recs\n");
> + return NULL;
> + }
> +
> + bitmap_set(ns->pgalloc_recs_bitmap, start, 1);
> + recs = (struct bch_nvm_pgalloc_recs *)(ns->kaddr + BCH_NVM_PAGES_SYS_RECS_HEAD_OFFSET)
> + + start;
> + return recs;
> +}
> +
> +static struct bch_nvm_pgalloc_recs *find_nvm_pgalloc_recs(struct bch_nvm_namespace *ns,
> + struct bch_nvm_pages_owner_head *owner_head, bool create)
> +{
> + int ns_nr = ns->sb->this_namespace_nr;
> + struct bch_nvm_pgalloc_recs *prev_recs = NULL, *recs = owner_head->recs[ns_nr];
> +
> + // If create=false, we return recs[nr]
> + if (!create)
> + return recs;
> +
> + // If create=true, it mean we need a empty struct bch_pgalloc_rec
> + // So we should find non-empty struct bch_nvm_pgalloc_recs or alloc
> + // new struct bch_nvm_pgalloc_recs. And return this bch_nvm_pgalloc_recs
> + while (recs && (recs->used == recs->size)) {
> + prev_recs = recs;
> + recs = recs->next;
> + }
> +
> + // Found empty struct bch_nvm_pgalloc_recs
> + if (recs)
> + return recs;
> + // Need alloc new struct bch_nvm_galloc_recs
> + recs = find_empty_pgalloc_recs();
> + if (recs) {
> + recs->next = NULL;
> + recs->owner = owner_head;
> + strncpy(recs->magic, bch_nvm_pages_pgalloc_magic, 16);
> + strncpy(recs->owner_uuid, owner_head->uuid, 16);
> + recs->size = BCH_MAX_REC;
> + recs->used = 0;
> +
> + if (prev_recs)
> + prev_recs->next = recs;
> + else
> + owner_head->recs[ns_nr] = recs;
> + }
> +
> + return recs;
> +}
> +
> +static void add_pgalloc_rec(struct bch_nvm_pgalloc_recs *recs, void *kaddr, int order)
> +{
> + int i;
> +
> + for (i = 0; i < recs->size; i++) {
> + if (recs->recs[i].pgoff == 0) {
> + recs->recs[i].pgoff = (unsigned long)kaddr >> PAGE_SHIFT;
> + recs->recs[i].order = order;
> + recs->used++;
> + break;
> + }
> + }
> + BUG_ON(i == recs->size);
> +}
> +
> +void *bch_nvm_alloc_pages(int order, const char *owner_uuid)
> +{
> + void *kaddr = NULL;
> + struct bch_nvm_pgalloc_recs *pgalloc_recs;
> + struct bch_nvm_pages_owner_head *owner_head;
> + int i, j;
> +
> + mutex_lock(&only_set->lock);
> + owner_head = find_owner_head(owner_uuid, true);
> +
> + for (j = 0; j < only_set->total_namespaces_nr; j++) {
> + struct bch_nvm_namespace *ns = only_set->nss[j];
> +
> + if (!ns || (ns->free < (1 << order)))
> + continue;
> +
> + for (i = order; i < BCH_MAX_ORDER; i++) {
> + struct list_head *list;
> + struct page *page, *buddy_page;
> +
> + if (list_empty(&ns->free_area[i]))
> + continue;
> +
> + list = ns->free_area[i].next;
> + page = container_of((void *)list, struct page, zone_device_data);
> +
> + list_del(list);
> +
> + while (i != order) {
> + buddy_page = nvm_vaddr_to_page(ns,
> + nvm_pgoff_to_vaddr(ns, page->index + (1 << (i - 1))));
> + set_page_private(buddy_page, i - 1);
> + buddy_page->index = page->index + (1 << (i - 1));
> + __SetPageBuddy(buddy_page);
> + list_add((struct list_head *)&buddy_page->zone_device_data,
> + &ns->free_area[i - 1]);
> + i--;
> + }
> +
> + set_page_private(page, order);
> + __ClearPageBuddy(page);
> + ns->free -= 1 << order;
> + kaddr = nvm_pgoff_to_vaddr(ns, page->index);
> + break;
> + }
> +
> + if (i != BCH_MAX_ORDER) {
> + pgalloc_recs = find_nvm_pgalloc_recs(ns, owner_head, true);
> + // ToDo: handle pgalloc_recs==NULL
> + add_pgalloc_rec(pgalloc_recs, kaddr, order);
> + break;
> + }
> + }
> +
> + mutex_unlock(&only_set->lock);
> + return kaddr;
> +}
> +EXPORT_SYMBOL_GPL(bch_nvm_alloc_pages);
> +
> static int init_owner_info(struct bch_nvm_namespace *ns)
> {
> struct bch_owner_list_head *owner_list_head = ns->sb->owner_list_head;
> diff --git a/drivers/md/bcache/nvm-pages.h b/drivers/md/bcache/nvm-pages.h
> index c158033e24f0..b2c0e0cfac20 100644
> --- a/drivers/md/bcache/nvm-pages.h
> +++ b/drivers/md/bcache/nvm-pages.h
> @@ -60,6 +60,7 @@ extern struct bch_nvm_set *only_set;
> struct bch_nvm_namespace *bch_register_namespace(const char *dev_path);
> int bch_nvm_init(void);
> void bch_nvm_exit(void);
> +void *bch_nvm_alloc_pages(int order, const char *owner_uuid);
>
> #else
>
> @@ -72,6 +73,11 @@ static inline int bch_nvm_init(void)
> }
> static inline void bch_nvm_exit(void) { }
>
> +static inline void *bch_nvm_alloc_pages(int order, const char *owner_uuid)
> +{
> + return NULL;
> +}
> +
> #endif /* CONFIG_BCACHE_NVM_PAGES */
>
> #endif /* _BCACHE_NVM_PAGES_H */
>
