diff --git a/[refs] b/[refs]
index ac599497f91c..145ad814d60e 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 910321ea817a202ff70fac666e37e2c8e2f88823
+refs/heads/master: b73d7fcecd93dc15eaa3c45c8c587b613f6673c4
diff --git a/trunk/mm/swapfile.c b/trunk/mm/swapfile.c
index f08d165871b3..ed5151079f59 100644
--- a/trunk/mm/swapfile.c
+++ b/trunk/mm/swapfile.c
@@ -318,10 +318,8 @@ static inline unsigned long scan_swap_map(struct swap_info_struct *si,
 	if (offset > si->highest_bit)
 		scan_base = offset = si->lowest_bit;
 
-	/* reuse swap entry of cache-only swap if not hibernation. */
-	if (vm_swap_full()
-		&& usage == SWAP_HAS_CACHE
-		&& si->swap_map[offset] == SWAP_HAS_CACHE) {
+	/* reuse swap entry of cache-only swap if not busy. */
+	if (vm_swap_full() && si->swap_map[offset] == SWAP_HAS_CACHE) {
 		int swap_was_freed;
 		spin_unlock(&swap_lock);
 		swap_was_freed = __try_to_reclaim_swap(si, offset);
@@ -688,6 +686,24 @@ int try_to_free_swap(struct page *page)
 	if (page_swapcount(page))
 		return 0;
 
+	/*
+	 * Once hibernation has begun to create its image of memory,
+	 * there's a danger that one of the calls to try_to_free_swap()
+	 * - most probably a call from __try_to_reclaim_swap() while
+	 * hibernation is allocating its own swap pages for the image,
+	 * but conceivably even a call from memory reclaim - will free
+	 * the swap from a page which has already been recorded in the
+	 * image as a clean swapcache page, and then reuse its swap for
+	 * another page of the image.  On waking from hibernation, the
+	 * original page might be freed under memory pressure, then
+	 * later read back in from swap, now with the wrong data.
+	 *
+	 * Hibernation clears bits from gfp_allowed_mask to prevent
+	 * memory reclaim from writing to disk, so check that here.
+	 */
+	if (!(gfp_allowed_mask & __GFP_IO))
+		return 0;
+
 	delete_from_swap_cache(page);
 	SetPageDirty(page);
 	return 1;