thp: fix interrupt unsafe locking in split_huge_page()

[linux.git] / mm / huge_memory.c

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index b1cf73bc3b12969f00740031ac60f28840ac212d..8ad580273521046904ec13478e7b897839d955d7 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -3357,6 +3357,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
        struct anon_vma *anon_vma;
        int count, mapcount, ret;
        bool mlocked;
+       unsigned long flags;
 
        VM_BUG_ON_PAGE(is_huge_zero_page(page), page);
        VM_BUG_ON_PAGE(!PageAnon(page), page);
@@ -3396,7 +3397,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
                lru_add_drain();
 
        /* Prevent deferred_split_scan() touching ->_count */
-       spin_lock(&split_queue_lock);
+       spin_lock_irqsave(&split_queue_lock, flags);
        count = page_count(head);
        mapcount = total_mapcount(head);
        if (!mapcount && count == 1) {
@@ -3404,11 +3405,11 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
                        split_queue_len--;
                        list_del(page_deferred_list(head));
                }
-               spin_unlock(&split_queue_lock);
+               spin_unlock_irqrestore(&split_queue_lock, flags);
                __split_huge_page(page, list);
                ret = 0;
        } else if (IS_ENABLED(CONFIG_DEBUG_VM) && mapcount) {
-               spin_unlock(&split_queue_lock);
+               spin_unlock_irqrestore(&split_queue_lock, flags);
                pr_alert("total_mapcount: %u, page_count(): %u\n",
                                mapcount, count);
                if (PageTail(page))
@@ -3416,7 +3417,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
                dump_page(page, "total_mapcount(head) > 0");
                BUG();
        } else {
-               spin_unlock(&split_queue_lock);
+               spin_unlock_irqrestore(&split_queue_lock, flags);
                unfreeze_page(anon_vma, head);
                ret = -EBUSY;
        }