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... > @@ -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? -- Jens Axboe