When !CONFIG_TRANSPARENT_HUGEPAGE, a non-folio compound page can appear in a userspace mapping via either vm_insert_*() functions or vm_operatios_struct->fault(). They are not folios, thus should not be considered for folio operations like split. Change memory_failure() and soft_offline_page() to reject these non-folio compound pages as EOPNOTSUPP. Add PageNonFolioCompound() helper function. This function is functionally equivalent to folio_test_large() && !folio_test_large_rmappable(), but it is supposed to be used on struct page. So open code it instead. Fixes: 689b8986776c ("mm/memory-failure: improve large block size folio handling") Reported-by: 是参差 Closes: https://lore.kernel.org/all/PS1PPF7E1D7501F1E4F4441E7ECD056DEADAB98A@PS1PPF7E1D7501F.apcprd02.prod.outlook.com/ Signed-off-by: Zi Yan --- include/linux/page-flags.h | 16 ++++++++++++++++ mm/memory-failure.c | 9 ++++++--- 2 files changed, 22 insertions(+), 3 deletions(-) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index f7a0e4af0c73..2fe8047f42a3 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -1102,6 +1102,22 @@ static inline bool folio_contain_hwpoisoned_page(struct folio *folio) bool is_free_buddy_page(const struct page *page); +static inline bool PageNonFolioCompound(const struct page *page) +{ + if (PageCompound(page)) { + const struct page *head = compound_head(page); + + /* + * Without CONFIG_TRANSPARENT_HUGEPAGE, PG_large_rmappable + * should not be set/used. + */ + return !IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) || + !test_bit(PG_large_rmappable, &head[1].flags.f); + } + + return false; +} + #ifdef CONFIG_MIGRATION /* * This page is migratable through movable_ops (for selected typed pages diff --git a/mm/memory-failure.c b/mm/memory-failure.c index cf0d526e6d41..8b6b5950bb66 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -2440,9 +2440,12 @@ int memory_failure(unsigned long pfn, int flags) folio = page_folio(p); - /* filter pages that are protected from hwpoison test by users */ + /* + * filter pages that are protected from hwpoison test by users or + * unsupported non folio compound ones + */ folio_lock(folio); - if (hwpoison_filter(p)) { + if (hwpoison_filter(p) || PageNonFolioCompound(p)) { ClearPageHWPoison(p); folio_unlock(folio); folio_put(folio); @@ -2945,7 +2948,7 @@ int soft_offline_page(unsigned long pfn, int flags) ret = get_hwpoison_page(page, flags | MF_SOFT_OFFLINE); put_online_mems(); - if (hwpoison_filter(page)) { + if (hwpoison_filter(page) || PageNonFolioCompound(page)) { if (ret > 0) put_page(page); -- 2.51.0