From bf6445bc8f778590ac754b06a8fe82ce5a9f818a Mon Sep 17 00:00:00 2001 From: Miaohe Lin Date: Tue, 22 Mar 2022 14:44:50 -0700 Subject: mm/memory-failure.c: make non-LRU movable pages unhandlable We can not really handle non-LRU movable pages in memory failure. Typically they are balloon, zsmalloc, etc. Assuming we run into a base (4K) non-LRU movable page, we could reach as far as identify_page_state(), it should not fall into any category except me_unknown. For the non-LRU compound movable pages, they could be taken for transhuge pages but it's unexpected to split non-LRU movable pages using split_huge_page_to_list in memory_failure. So we could just simply make non-LRU movable pages unhandlable to avoid these possible nasty cases. Link: https://lkml.kernel.org/r/20220312074613.4798-4-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Suggested-by: Yang Shi Reviewed-by: Yang Shi Acked-by: Naoya Horiguchi Cc: Borislav Petkov Cc: Mike Kravetz Cc: Tony Luck Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory-failure.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) (limited to 'mm') diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 47be518f075e..1434e0608d5a 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1176,12 +1176,18 @@ void ClearPageHWPoisonTakenOff(struct page *page) * does not return true for hugetlb or device memory pages, so it's assumed * to be called only in the context where we never have such pages. */ -static inline bool HWPoisonHandlable(struct page *page) +static inline bool HWPoisonHandlable(struct page *page, unsigned long flags) { - return PageLRU(page) || __PageMovable(page) || is_free_buddy_page(page); + bool movable = false; + + /* Soft offline could mirgate non-LRU movable pages */ + if ((flags & MF_SOFT_OFFLINE) && __PageMovable(page)) + movable = true; + + return movable || PageLRU(page) || is_free_buddy_page(page); } -static int __get_hwpoison_page(struct page *page) +static int __get_hwpoison_page(struct page *page, unsigned long flags) { struct page *head = compound_head(page); int ret = 0; @@ -1196,7 +1202,7 @@ static int __get_hwpoison_page(struct page *page) * for any unsupported type of page in order to reduce the risk of * unexpected races caused by taking a page refcount. */ - if (!HWPoisonHandlable(head)) + if (!HWPoisonHandlable(head, flags)) return -EBUSY; if (get_page_unless_zero(head)) { @@ -1221,7 +1227,7 @@ static int get_any_page(struct page *p, unsigned long flags) try_again: if (!count_increased) { - ret = __get_hwpoison_page(p); + ret = __get_hwpoison_page(p, flags); if (!ret) { if (page_count(p)) { /* We raced with an allocation, retry. */ @@ -1249,7 +1255,7 @@ try_again: } } - if (PageHuge(p) || HWPoisonHandlable(p)) { + if (PageHuge(p) || HWPoisonHandlable(p, flags)) { ret = 1; } else { /* @@ -2302,7 +2308,7 @@ int soft_offline_page(unsigned long pfn, int flags) retry: get_online_mems(); - ret = get_hwpoison_page(page, flags); + ret = get_hwpoison_page(page, flags | MF_SOFT_OFFLINE); put_online_mems(); if (ret > 0) { -- cgit v1.2.3