diff options
| -rw-r--r-- | mm/swap_state.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/mm/swap_state.c b/mm/swap_state.c index 71ce2d1ccbf7..ed91091d1e68 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -242,6 +242,17 @@ int add_to_swap(struct page *page) * clear SWAP_HAS_CACHE flag. */ goto fail; + /* + * Normally the page will be dirtied in unmap because its pte should be + * dirty. A special case is MADV_FREE page. The page'e pte could have + * dirty bit cleared but the page's SwapBacked bit is still set because + * clearing the dirty bit and SwapBacked bit has no lock protected. For + * such page, unmap will not set dirty bit for it, so page reclaim will + * not write the page out. This can cause data corruption when the page + * is swap in later. Always setting the dirty bit for the page solves + * the problem. + */ + set_page_dirty(page); return 1; |