diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index ed9c86cd053e81f32b5c6551d3246461c00d5d30..4789c42d9a3ac503d53ba6ea77fe7fadbee21682 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -353,7 +353,7 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions,
 {
 	struct io io;
 
-	if (num_regions > 1 && rw != WRITE) {
+	if (num_regions > 1 && (rw & RW_MASK) != WRITE) {
 		WARN_ON(1);
 		return -EIO;
 	}
@@ -390,7 +390,7 @@ static int async_io(struct dm_io_client *client, unsigned int num_regions,
 {
 	struct io *io;
 
-	if (num_regions > 1 && rw != WRITE) {
+	if (num_regions > 1 && (rw & RW_MASK) != WRITE) {
 		WARN_ON(1);
 		fn(1, context);
 		return -EIO;
@@ -436,7 +436,12 @@ static int dp_init(struct dm_io_request *io_req, struct dpages *dp)
 }
 
 /*
- * New collapsed (a)synchronous interface
+ * New collapsed (a)synchronous interface.
+ *
+ * If the IO is asynchronous (i.e. it has notify.fn), you must either unplug
+ * the queue with blk_unplug() some time later or set the BIO_RW_SYNC bit in
+ * io_req->bi_rw. If you fail to do one of these, the IO will be submitted to
+ * the disk after q->unplug_delay, which defaults to 3ms in blk-settings.c.
  */
 int dm_io(struct dm_io_request *io_req, unsigned num_regions,
 	  struct dm_io_region *where, unsigned long *sync_error_bits)
diff --git a/drivers/md/dm-kcopyd.c b/drivers/md/dm-kcopyd.c
index ee9583bee04d549cad92a7a809c220d6071f89bd..996802b8a4522e50126365d070f21458f9b68be2 100644
--- a/drivers/md/dm-kcopyd.c
+++ b/drivers/md/dm-kcopyd.c
@@ -332,7 +332,7 @@ static int run_io_job(struct kcopyd_job *job)
 {
 	int r;
 	struct dm_io_request io_req = {
-		.bi_rw = job->rw,
+		.bi_rw = job->rw | (1 << BIO_RW_SYNC),
 		.mem.type = DM_IO_PAGE_LIST,
 		.mem.ptr.pl = job->pages,
 		.mem.offset = job->offset,
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 3b9532fc294c9952fc80cb31fd028f82e25040f5..ff05fe89308313ab5792a6b3dc9146db3e585c6a 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -1297,6 +1297,8 @@ static void do_mirror(struct work_struct *work)
 	do_reads(ms, &reads);
 	do_writes(ms, &writes);
 	do_failures(ms, &failures);
+
+	dm_table_unplug_all(ms->ti->table);
 }