[PATCH v13 04/12] bcache: bch_nvmpg_alloc_pages() of the buddy

Coly Li
2021-12-12T17:06:25Z

From: Jianpeng Ma <jianpeng.ma@intel.com>

This patch implements the bch_nvmpg_alloc_pages() of the nvm pages buddy
allocator. In terms of function, this func is like current
page-buddy-alloc. But the differences are:
a: it need owner_uuid as parameter which record owner info. And it
make those info persistence.
b: it don't need flags like GFP_*. All allocs are the equal.
c: it don't trigger other ops etc swap/recycle.

Signed-off-by: Jianpeng Ma <jianpeng.ma@intel.com>
Co-developed-by: Qiaowei Ren <qiaowei.ren@intel.com>
Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
---
drivers/md/bcache/nvmpg.c | 221 ++++++++++++++++++++++++++++++++++++++
drivers/md/bcache/nvmpg.h | 9 ++
2 files changed, 230 insertions(+)

diff --git a/drivers/md/bcache/nvmpg.c b/drivers/md/bcache/nvmpg.c
index 2b70ee4a6028..a920779eb548 100644
--- a/drivers/md/bcache/nvmpg.c
+++ b/drivers/md/bcache/nvmpg.c
@@ -42,6 +42,11 @@ void *bch_nvmpg_offset_to_ptr(unsigned long offset)
return NULL;
}

+static unsigned long bch_nvmpg_offset_to_pgoff(unsigned long nvmpg_offset)
+{
+ return BCH_NVMPG_GET_OFFSET(nvmpg_offset) >> PAGE_SHIFT;
+}
+
unsigned long bch_nvmpg_ptr_to_offset(struct bch_nvmpg_ns *ns, void *ptr)
{
int ns_id = ns->ns_id;
@@ -60,6 +65,15 @@ static void *bch_nvmpg_pgoff_to_ptr(struct bch_nvmpg_ns *ns, pgoff_t pgoff)
return ns->base_addr + (pgoff << PAGE_SHIFT);
}

+static unsigned long bch_nvmpg_pgoff_to_offset(struct bch_nvmpg_ns *ns,
+ pgoff_t pgoff)
+{
+ int ns_id = ns->ns_id;
+ unsigned long offset = pgoff << PAGE_SHIFT;
+
+ return BCH_NVMPG_OFFSET(ns_id, offset);
+}
+
static void *bch_nvmpg_rec_to_ptr(struct bch_nvmpg_rec *r)
{
struct bch_nvmpg_ns *ns = global_nvmpg_set->ns_tbl[r->ns_id];
@@ -269,6 +283,213 @@ static void bch_nvmpg_init_free_space(struct bch_nvmpg_ns *ns)
}
}

+
+/* If not found, it will create if create == true */
+static struct bch_nvmpg_head *find_nvmpg_head(const char *uuid, bool create)
+{
+ struct bch_nvmpg_set_header *set_header = global_nvmpg_set->set_header;
+ struct bch_nvmpg_head *head = NULL;
+ int i;
+
+ if (set_header == NULL)
+ goto out;
+
+ for (i = 0; i < set_header->size; i++) {
+ struct bch_nvmpg_head *h = &set_header->heads[i];
+
+ if (h->state != BCH_NVMPG_HD_STAT_ALLOC)
+ continue;
+
+ if (!memcmp(uuid, h->uuid, 16)) {
+ head = h;
+ break;
+ }
+ }
+
+ if (!head && create) {
+ u32 used = set_header->used;
+
+ if (set_header->size > used) {
+ head = &set_header->heads[used];
+ memset(head, 0, sizeof(struct bch_nvmpg_head));
+ head->state = BCH_NVMPG_HD_STAT_ALLOC;
+ memcpy(head->uuid, uuid, 16);
+ global_nvmpg_set->heads_used++;
+ set_header->used++;
+ } else
+ pr_info("No free bch_nvmpg_head\n");
+ }
+
+out:
+ return head;
+}
+
+static struct bch_nvmpg_recs *find_empty_nvmpg_recs(void)
+{
+ unsigned int start;
+ struct bch_nvmpg_ns *ns = global_nvmpg_set->ns_tbl[0];
+ struct bch_nvmpg_recs *recs;
+
+ start = bitmap_find_next_zero_area(ns->recs_bitmap,
+ BCH_MAX_PGALLOC_RECS, 0, 1, 0);
+ if (start > BCH_MAX_PGALLOC_RECS) {
+ pr_info("No free struct bch_nvmpg_recs\n");
+ return NULL;
+ }
+
+ bitmap_set(ns->recs_bitmap, start, 1);
+ recs = (struct bch_nvmpg_recs *)
+ bch_nvmpg_offset_to_ptr(BCH_NVMPG_SYSRECS_OFFSET)
+ + start;
+
+ memset(recs, 0, sizeof(struct bch_nvmpg_recs));
+ return recs;
+}
+
+
+static struct bch_nvmpg_recs *find_nvmpg_recs(struct bch_nvmpg_ns *ns,
+ struct bch_nvmpg_head *head,
+ bool create)
+{
+ int ns_id = ns->sb->this_ns;
+ struct bch_nvmpg_recs *prev_recs = NULL, *recs = NULL;
+
+ recs = bch_nvmpg_offset_to_ptr(head->recs_offset[ns_id]);
+
+ /* If create=false, we return recs[nr] */
+ if (!create)
+ return recs;
+
+ /*
+ * If create=true, it mean we need a empty struct bch_nvmpg_rec
+ * So we should find non-empty struct bch_nvmpg_recs or alloc
+ * new struct bch_nvmpg_recs. And return this bch_nvmpg_recs
+ */
+ while (recs && (recs->used == recs->size)) {
+ prev_recs = recs;
+ recs = bch_nvmpg_offset_to_ptr(recs->next_offset);
+ }
+
+ /* Found empty struct bch_nvmpg_recs */
+ if (recs)
+ return recs;
+
+ /* Need alloc new struct bch_nvmpg_recs */
+ recs = find_empty_nvmpg_recs();
+ if (recs) {
+ unsigned long offset;
+
+ recs->next_offset = 0;
+ recs->head_offset = bch_nvmpg_ptr_to_offset(ns, head);
+ memcpy(recs->magic, bch_nvmpg_recs_magic, 16);
+ memcpy(recs->uuid, head->uuid, 16);
+ recs->size = BCH_NVMPG_MAX_RECS;
+ recs->used = 0;
+
+ offset = bch_nvmpg_ptr_to_offset(ns, recs);
+ if (prev_recs)
+ prev_recs->next_offset = offset;
+ else
+ head->recs_offset[ns_id] = offset;
+ }
+
+ return recs;
+}
+
+static void add_nvmpg_rec(struct bch_nvmpg_ns *ns,
+ struct bch_nvmpg_recs *recs,
+ unsigned long nvmpg_offset,
+ int order)
+{
+ int i, ns_id;
+ unsigned long pgoff;
+
+ pgoff = bch_nvmpg_offset_to_pgoff(nvmpg_offset);
+ ns_id = ns->sb->this_ns;
+
+ for (i = 0; i < recs->size; i++) {
+ if (recs->recs[i].pgoff == 0) {
+ recs->recs[i].pgoff = pgoff;
+ recs->recs[i].order = order;
+ recs->recs[i].ns_id = ns_id;
+ recs->used++;
+ break;
+ }
+ }
+ BUG_ON(i == recs->size);
+}
+
+
+unsigned long bch_nvmpg_alloc_pages(int order, const char *uuid)
+{
+ unsigned long nvmpg_offset = 0;
+ struct bch_nvmpg_head *head;
+ int n, o;
+
+ mutex_lock(&global_nvmpg_set->lock);
+ head = find_nvmpg_head(uuid, true);
+
+ if (!head) {
+ pr_err("Cannot find bch_nvmpg_recs by uuid.\n");
+ goto unlock;
+ }
+
+ for (n = 0; n < global_nvmpg_set->total_ns; n++) {
+ struct bch_nvmpg_ns *ns = global_nvmpg_set->ns_tbl[n];
+
+ if (!ns || (ns->free < (1L << order)))
+ continue;
+
+ for (o = order; o < BCH_MAX_ORDER; o++) {
+ struct list_head *list;
+ struct page *page, *buddy_page;
+
+ if (list_empty(&ns->free_area[o]))
+ continue;
+
+ list = ns->free_area[o].next;
+ page = container_of((void *)list, struct page,
+ zone_device_data);
+
+ list_del(list);
+
+ while (o != order) {
+ void *addr;
+ pgoff_t pgoff;
+
+ pgoff = page->index + (1L << (o - 1));
+ addr = bch_nvmpg_pgoff_to_ptr(ns, pgoff);
+ buddy_page = bch_nvmpg_va_to_pg(addr);
+ set_page_private(buddy_page, o - 1);
+ buddy_page->index = pgoff;
+ __SetPageBuddy(buddy_page);
+ list_add((struct list_head *)&buddy_page->zone_device_data,
+ &ns->free_area[o - 1]);
+ o--;
+ }
+
+ set_page_private(page, order);
+ __ClearPageBuddy(page);
+ ns->free -= 1L << order;
+ nvmpg_offset = bch_nvmpg_pgoff_to_offset(ns, page->index);
+ break;
+ }
+
+ if (o < BCH_MAX_ORDER) {
+ struct bch_nvmpg_recs *recs;
+
+ recs = find_nvmpg_recs(ns, head, true);
+ /* ToDo: handle pgalloc_recs==NULL */
+ add_nvmpg_rec(ns, recs, nvmpg_offset, order);
+ break;
+ }
+ }
+
+unlock:
+ mutex_unlock(&global_nvmpg_set->lock);
+ return nvmpg_offset;
+}
+
static int attach_nvmpg_set(struct bch_nvmpg_ns *ns)
{
struct bch_nvmpg_sb *sb = ns->sb;
diff --git a/drivers/md/bcache/nvmpg.h b/drivers/md/bcache/nvmpg.h
index 55778d4db7da..d03f3241b45a 100644
--- a/drivers/md/bcache/nvmpg.h
+++ b/drivers/md/bcache/nvmpg.h
@@ -76,6 +76,9 @@ struct bch_nvmpg_set {
/* Indicate which field in bch_nvmpg_sb to be updated */
#define BCH_NVMPG_TOTAL_NS 0 /* total_ns */

+#define BCH_PGOFF_TO_KVADDR(pgoff) \
+ ((void *)((unsigned long)(pgoff) << PAGE_SHIFT))
+
#define BCH_MAX_PGALLOC_RECS \
(min_t(unsigned int, 64, \
(BCH_NVMPG_START - BCH_NVMPG_SYSRECS_OFFSET) / \
@@ -89,6 +92,7 @@ unsigned long bch_nvmpg_ptr_to_offset(struct bch_nvmpg_ns *ns, void *ptr);
struct bch_nvmpg_ns *bch_register_namespace(const char *dev_path);
int bch_nvmpg_init(void);
void bch_nvmpg_exit(void);
+unsigned long bch_nvmpg_alloc_pages(int order, const char *uuid);

#else

@@ -104,6 +108,11 @@ static inline int bch_nvmpg_init(void)

static inline void bch_nvmpg_exit(void) { }

+static inline unsigned long bch_nvmpg_alloc_pages(int order, const char *uuid)
+{
+ return 0;
+}
+
#endif /* CONFIG_BCACHE_NVM_PAGES */

#endif /* _BCACHE_NVM_PAGES_H */
--
2.31.1