diff options
Diffstat (limited to 'include/linux/page-flags.h')
| -rw-r--r-- | include/linux/page-flags.h | 71 |
1 files changed, 57 insertions, 14 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 36d283552f80..e6a21b62dcce 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -226,11 +226,48 @@ static __always_inline const struct page *page_fixed_fake_head(const struct page } return page; } + +static __always_inline bool page_count_writable(const struct page *page, int u) +{ + if (!static_branch_unlikely(&hugetlb_optimize_vmemmap_key)) + return true; + + /* + * The refcount check is ordered before the fake-head check to prevent + * the following race: + * CPU 1 (HVO) CPU 2 (speculative PFN walker) + * + * page_ref_freeze() + * synchronize_rcu() + * rcu_read_lock() + * page_is_fake_head() is false + * vmemmap_remap_pte() + * XXX: struct page[] becomes r/o + * + * page_ref_unfreeze() + * page_ref_count() is not zero + * + * atomic_add_unless(&page->_refcount) + * XXX: try to modify r/o struct page[] + * + * The refcount check also prevents modification attempts to other (r/o) + * tail pages that are not fake heads. + */ + if (atomic_read_acquire(&page->_refcount) == u) + return false; + + return page_fixed_fake_head(page) == page; +} #else static inline const struct page *page_fixed_fake_head(const struct page *page) { return page; } + +static inline bool page_count_writable(const struct page *page, int u) +{ + return true; +} #endif static __always_inline int page_is_fake_head(const struct page *page) @@ -673,12 +710,6 @@ PAGEFLAG_FALSE(VmemmapSelfHosted, vmemmap_self_hosted) #define PAGE_MAPPING_KSM (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) #define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) -/* - * Different with flags above, this flag is used only for fsdax mode. It - * indicates that this page->mapping is now under reflink case. - */ -#define PAGE_MAPPING_DAX_SHARED ((void *)0x1) - static __always_inline bool folio_mapping_flags(const struct folio *folio) { return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) != 0; @@ -925,14 +956,15 @@ FOLIO_FLAG_FALSE(has_hwpoisoned) enum pagetype { /* 0x00-0x7f are positive numbers, ie mapcount */ /* Reserve 0x80-0xef for mapcount overflow. */ - PGTY_buddy = 0xf0, - PGTY_offline = 0xf1, - PGTY_table = 0xf2, - PGTY_guard = 0xf3, - PGTY_hugetlb = 0xf4, - PGTY_slab = 0xf5, - PGTY_zsmalloc = 0xf6, - PGTY_unaccepted = 0xf7, + PGTY_buddy = 0xf0, + PGTY_offline = 0xf1, + PGTY_table = 0xf2, + PGTY_guard = 0xf3, + PGTY_hugetlb = 0xf4, + PGTY_slab = 0xf5, + PGTY_zsmalloc = 0xf6, + PGTY_unaccepted = 0xf7, + PGTY_large_kmalloc = 0xf8, PGTY_mapcount_underflow = 0xff }; @@ -1075,6 +1107,7 @@ PAGE_TYPE_OPS(Zsmalloc, zsmalloc, zsmalloc) * Serialized with zone lock. */ PAGE_TYPE_OPS(Unaccepted, unaccepted, unaccepted) +FOLIO_TYPE_OPS(large_kmalloc, large_kmalloc) /** * PageHuge - Determine if the page belongs to hugetlbfs @@ -1104,6 +1137,12 @@ static inline bool is_page_hwpoison(const struct page *page) return folio_test_hugetlb(folio) && PageHWPoison(&folio->page); } +static inline bool folio_contain_hwpoisoned_page(struct folio *folio) +{ + return folio_test_hwpoison(folio) || + (folio_test_large(folio) && folio_test_has_hwpoisoned(folio)); +} + bool is_free_buddy_page(const struct page *page); PAGEFLAG(Isolated, isolated, PF_ANY); @@ -1191,6 +1230,10 @@ static inline int folio_has_private(const struct folio *folio) return !!(folio->flags & PAGE_FLAGS_PRIVATE); } +static inline bool folio_test_large_maybe_mapped_shared(const struct folio *folio) +{ + return test_bit(FOLIO_MM_IDS_SHARED_BITNUM, &folio->_mm_ids); +} #undef PF_ANY #undef PF_HEAD #undef PF_NO_TAIL |