diff --git a/include/linux/swap_slots.h b/include/linux/swap_slots.h
index ba5623b..6ef92d1 100644
--- a/include/linux/swap_slots.h
+++ b/include/linux/swap_slots.h
@@ -25,4 +25,6 @@ void reenable_swap_slots_cache_unlock(void);
 int enable_swap_slots_cache(void);
 int free_swap_slot(swp_entry_t entry);
 
+extern bool swap_slot_cache_enabled;
+
 #endif /* _LINUX_SWAP_SLOTS_H */
diff --git a/mm/swap_slots.c b/mm/swap_slots.c
index ebf4f1c..9b5bc86 100644
--- a/mm/swap_slots.c
+++ b/mm/swap_slots.c
@@ -36,7 +36,7 @@
 
 static DEFINE_PER_CPU(struct swap_slots_cache, swp_slots);
 static bool	swap_slot_cache_active;
-static bool	swap_slot_cache_enabled;
+bool	swap_slot_cache_enabled;
 static bool	swap_slot_cache_initialized;
 DEFINE_MUTEX(swap_slots_cache_mutex);
 /* Serialize swap slots cache enable/disable operations */
diff --git a/mm/swap_state.c b/mm/swap_state.c
index e1f07ca..473b71e 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -324,9 +324,16 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
 		if (found_page)
 			break;
 
-		/* Just skip read ahead for unused swap slot */
-		if (!__swp_swapcount(entry))
-			return NULL;
+		/*
+		 * Just skip read ahead for unused swap slot.
+		 * During swap_off when swap_slot_cache is disabled,
+		 * we have to handle the race between putting
+		 * swap entry in swap cache and marking swap slot
+		 * as SWAP_HAS_CACHE.  That's done in later part of code or
+		 * else swap_off will be aborted if we return NULL.
+		 */
+		if (!__swp_swapcount(entry) && swap_slot_cache_enabled)
+			break;
 
 		/*
 		 * Get a new page to read into from swap.