net: Add FLOWI_FLAG_CAN_SLEEP.

And set is in contexts where the route resolution can sleep.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/flow.h b/include/net/flow.h
index f2080e6..fd04138 100644
--- a/include/net/flow.h
+++ b/include/net/flow.h
@@ -50,6 +50,7 @@
 	__u8	flags;
 #define FLOWI_FLAG_ANYSRC		0x01
 #define FLOWI_FLAG_PRECOW_METRICS	0x02
+#define FLOWI_FLAG_CAN_SLEEP		0x04
 	union {
 		struct {
 			__be16	sport;