diff --git a/[refs] b/[refs]
index 7669b996bc93..6bcb300e74c0 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 8f2ae0faa3a119158c4dcfe89926d6fad5f5332c
+refs/heads/master: 3399446632739fcd05fd8b272b476a69c6e6d14a
diff --git a/trunk/include/linux/swap.h b/trunk/include/linux/swap.h
index bf4eb62506db..7cdd63366f88 100644
--- a/trunk/include/linux/swap.h
+++ b/trunk/include/linux/swap.h
@@ -19,6 +19,7 @@ struct bio;
 #define SWAP_FLAG_PREFER	0x8000	/* set if swap priority specified */
 #define SWAP_FLAG_PRIO_MASK	0x7fff
 #define SWAP_FLAG_PRIO_SHIFT	0
+#define SWAP_FLAG_DISCARD	0x10000 /* discard swap cluster after use */
 
 static inline int current_is_kswapd(void)
 {
@@ -142,7 +143,7 @@ struct swap_extent {
 enum {
 	SWP_USED	= (1 << 0),	/* is slot in swap_info[] used? */
 	SWP_WRITEOK	= (1 << 1),	/* ok to write to this swap?	*/
-	SWP_DISCARDABLE = (1 << 2),	/* blkdev supports discard */
+	SWP_DISCARDABLE = (1 << 2),	/* swapon+blkdev support discard */
 	SWP_DISCARDING	= (1 << 3),	/* now discarding a free cluster */
 	SWP_SOLIDSTATE	= (1 << 4),	/* blkdev seeks are cheap */
 	SWP_CONTINUED	= (1 << 5),	/* swap_map has count continuation */
diff --git a/trunk/mm/swapfile.c b/trunk/mm/swapfile.c
index 1894dead0b58..7c703ff2f36f 100644
--- a/trunk/mm/swapfile.c
+++ b/trunk/mm/swapfile.c
@@ -2047,7 +2047,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 			p->flags |= SWP_SOLIDSTATE;
 			p->cluster_next = 1 + (random32() % p->highest_bit);
 		}
-		if (discard_swap(p) == 0)
+		if (discard_swap(p) == 0 && (swap_flags & SWAP_FLAG_DISCARD))
 			p->flags |= SWP_DISCARDABLE;
 	}