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 <linmiaohe@huawei.com>
Suggested-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 47be518..1434e06 100644 (file)
--- 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) {