Signed-off-by: Shaohua Li <shaohua.li@intel.com>

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 52b39f3..07a930d 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1424,6 +1424,13 @@ static int dm_make_request(struct request_queue *q, struct bio *bio)
 {
 	struct mapped_device *md = q->queuedata;
 
+	if (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) {
+		if (bio->bi_rw & REQ_FLUSH)
+			bio->bi_rw |= REQ_CLONED_FLUSH;
+		if (bio->bi_rw & REQ_FUA)
+			bio->bi_rw |= REQ_CLONED_FUA;
+		bio->bi_rw &= ~(REQ_FLUSH|REQ_FUA);
+	}
 	return md->saved_make_request_fn(q, bio); /* call __make_request() */
 }
 
@@ -1547,6 +1554,14 @@ static int dm_prep_fn(struct request_queue *q, struct request *rq)
 	if (!clone)
 		return BLKPREP_DEFER;
 
+	if (rq->cmd_flags & REQ_CLONED_FLUSH)
+		clone->cmd_flags |= REQ_FLUSH;
+	if (rq->cmd_flags & REQ_CLONED_FUA)
+		clone->cmd_flags |= REQ_FUA;
+
+	rq->cmd_flags &=  ~(REQ_FLUSH|REQ_FUA);
+	clone->cmd_flags &=  ~(REQ_FLUSH|REQ_FUA);
+
 	rq->special = clone;
 	rq->cmd_flags |= REQ_DONTPREP;
 
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 71fc53b..6ef5dc3 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -153,6 +153,8 @@ enum rq_flag_bits {
 	__REQ_FLUSH_SEQ,	/* request for flush sequence */
 	__REQ_IO_STAT,		/* account I/O stat */
 	__REQ_MIXED_MERGE,	/* merge of different types, fail separately */
+	__REQ_CLONED_FLUSH,
+	__REQ_CLONED_FUA,
 	__REQ_NR_BITS,		/* stops here */
 };
 
@@ -170,7 +172,7 @@ enum rq_flag_bits {
 	(REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
 #define REQ_COMMON_MASK \
 	(REQ_WRITE | REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_PRIO | \
-	 REQ_DISCARD | REQ_NOIDLE | REQ_FLUSH | REQ_FUA | REQ_SECURE)
+	 REQ_DISCARD | REQ_NOIDLE | REQ_FLUSH | REQ_FUA | REQ_SECURE | REQ_CLONED_FLUSH | REQ_CLONED_FUA)
 #define REQ_CLONE_MASK		REQ_COMMON_MASK
 
 #define REQ_RAHEAD		(1 << __REQ_RAHEAD)
@@ -194,5 +196,7 @@ enum rq_flag_bits {
 #define REQ_IO_STAT		(1 << __REQ_IO_STAT)
 #define REQ_MIXED_MERGE		(1 << __REQ_MIXED_MERGE)
 #define REQ_SECURE		(1 << __REQ_SECURE)
+#define REQ_CLONED_FLUSH	(1 << __REQ_CLONED_FLUSH)
+#define REQ_CLONED_FUA		(1 << __REQ_CLONED_FUA)
 
 #endif /* __LINUX_BLK_TYPES_H */