On 12/13/21 4:16 AM, Jens Axboe wrote:
On 12/12/21 10:05 AM, Coly Li wrote:
diff --git a/drivers/md/bcache/nvmpg.c b/drivers/md/bcache/nvmpg.c
index a920779eb548..8ce0c4389b42 100644
--- a/drivers/md/bcache/nvmpg.c
+++ b/drivers/md/bcache/nvmpg.c
@@ -248,6 +248,57 @@ static int init_nvmpg_set_header(struct bch_nvmpg_ns *ns)
return rc;
}
+static void __free_space(struct bch_nvmpg_ns *ns, unsigned long nvmpg_offset,
+ int order)
+{
+ unsigned long add_pages = (1L << order);
+ pgoff_t pgoff;
+ struct page *page;
+ void *va;
+
+ if (nvmpg_offset == 0) {
+ pr_err("free pages on offset 0\n");
+ return;
+ }
+
+ page = bch_nvmpg_va_to_pg(bch_nvmpg_offset_to_ptr(nvmpg_offset));
+ WARN_ON((!page) || (page->private != order));
+ pgoff = page->index;
+
+ while (order < BCH_MAX_ORDER - 1) {
+ struct page *buddy_page;
+
+ pgoff_t buddy_pgoff = pgoff ^ (1L << order);
+ pgoff_t parent_pgoff = pgoff & ~(1L << order);
+
+ if ((parent_pgoff + (1L << (order + 1)) > ns->pages_total))
+ break;
+
+ va = bch_nvmpg_pgoff_to_ptr(ns, buddy_pgoff);
+ buddy_page = bch_nvmpg_va_to_pg(va);
+ WARN_ON(!buddy_page);
+
+ if (PageBuddy(buddy_page) && (buddy_page->private == order)) {
+ list_del((struct list_head *)&buddy_page->zone_device_data);
+ __ClearPageBuddy(buddy_page);
+ pgoff = parent_pgoff;
+ order++;
+ continue;
+ }
+ break;
+ }
+
+ va = bch_nvmpg_pgoff_to_ptr(ns, pgoff);
+ page = bch_nvmpg_va_to_pg(va);
+ WARN_ON(!page);
+ list_add((struct list_head *)&page->zone_device_data,
+ &ns->free_area[order]);
+ page->index = pgoff;
+ set_page_private(page, order);
+ __SetPageBuddy(page);
+ ns->free += add_pages;
+}
There are 3 WARN_ON's in here. If you absolutely must use a WARN_ON,
then make them WARN_ON_ONCE(). Ditto in other spots in this patch.
+void bch_nvmpg_free_pages(unsigned long nvmpg_offset, int order,
+ const char *uuid)
+{
+ struct bch_nvmpg_ns *ns;
+ struct bch_nvmpg_head *head;
+ struct bch_nvmpg_recs *recs;
+ int r;
+
+ mutex_lock(&global_nvmpg_set->lock);
+
+ ns = global_nvmpg_set->ns_tbl[BCH_NVMPG_GET_NS_ID(nvmpg_offset)];
+ if (!ns) {
+ pr_err("can't find namespace by given kaddr from namespace\n");
+ goto unlock;
+ }
+
+ head = find_nvmpg_head(uuid, false);
+ if (!head) {
+ pr_err("can't found bch_nvmpg_head by uuid\n");
+ goto unlock;
+ }
+
+ recs = find_nvmpg_recs(ns, head, false);
+ if (!recs) {
+ pr_err("can't find bch_nvmpg_recs by uuid\n");
+ goto unlock;
+ }
+
+ r = remove_nvmpg_rec(recs, ns->sb->this_ns, nvmpg_offset, order);
+ if (r < 0) {
+ pr_err("can't find bch_nvmpg_rec\n");
+ goto unlock;
+ }
+
+ __free_space(ns, nvmpg_offset, order);
+
+unlock:
+ mutex_unlock(&global_nvmpg_set->lock);
+}
Again tons of useless error prints. Make them return a proper error
instad of just making things void...
Copied. It will be improved as you suggested.
@@ -686,6 +835,7 @@ struct bch_nvmpg_ns *bch_register_namespace(const char *dev_path)
ns->pages_offset = sb->pages_offset;
ns->pages_total = sb->pages_total;
ns->sb = sb;
+ /* increase by __free_space() */
ns->free = 0;
ns->bdev = bdev;
ns->set = global_nvmpg_set;
Does that hunk belong in here?
Could you please give me more detailed explanation of the above
question? Do you mention the bch_register_namespace() function, or the
code block which initializes members of ns?
Thank you.
Coly Li
