diff options
Diffstat (limited to 'mm/util.c')
| -rw-r--r-- | mm/util.c | 30 |
1 files changed, 18 insertions, 12 deletions
diff --git a/mm/util.c b/mm/util.c index bacabe446906..6c1fe9bee30a 100644 --- a/mm/util.c +++ b/mm/util.c @@ -705,30 +705,36 @@ struct anon_vma *page_anon_vma(struct page *page) return __page_rmapping(page); } -struct address_space *page_mapping(struct page *page) +/** + * folio_mapping - Find the mapping where this folio is stored. + * @folio: The folio. + * + * For folios which are in the page cache, return the mapping that this + * page belongs to. Folios in the swap cache return the swap mapping + * this page is stored in (which is different from the mapping for the + * swap file or swap device where the data is stored). + * + * You can call this for folios which aren't in the swap cache or page + * cache and it will return NULL. + */ +struct address_space *folio_mapping(struct folio *folio) { struct address_space *mapping; - page = compound_head(page); - /* This happens if someone calls flush_dcache_page on slab page */ - if (unlikely(PageSlab(page))) + if (unlikely(folio_test_slab(folio))) return NULL; - if (unlikely(PageSwapCache(page))) { - swp_entry_t entry; - - entry.val = page_private(page); - return swap_address_space(entry); - } + if (unlikely(folio_test_swapcache(folio))) + return swap_address_space(folio_swap_entry(folio)); - mapping = page->mapping; + mapping = folio->mapping; if ((unsigned long)mapping & PAGE_MAPPING_ANON) return NULL; return (void *)((unsigned long)mapping & ~PAGE_MAPPING_FLAGS); } -EXPORT_SYMBOL(page_mapping); +EXPORT_SYMBOL(folio_mapping); /* Slow path of page_mapcount() for compound pages */ int __page_mapcount(struct page *page) |