diff options
| -rw-r--r-- | mm/swapfile.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index f4360182760..9ce7f81c8ab 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -889,7 +889,16 @@ static int try_to_unuse(unsigned int type) lock_page(page); wait_on_page_writeback(page); } - if (PageSwapCache(page)) + + /* + * It is conceivable that a racing task removed this page from + * swap cache just before we acquired the page lock at the top, + * or while we dropped it in unuse_mm(). The page might even + * be back in swap cache on another swap area: that we must not + * delete, since it may not have been written out to swap yet. + */ + if (PageSwapCache(page) && + likely(page_private(page) == entry.val)) delete_from_swap_cache(page); /* |