From: Mikulas Patocka <mpatocka@redhat.com>

Set the bit that prevents queue plugging --- so that the request goes
immediately to the device.

This makes dm-delay more precise, without the patch, there could be additional
3ms delay.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

---
 drivers/md/dm-delay.c |    1 +
 1 file changed, 1 insertion(+)

Index: linux-2.6.30-rc8-fast/drivers/md/dm-delay.c
===================================================================
--- linux-2.6.30-rc8-fast.orig/drivers/md/dm-delay.c	2009-06-09 01:31:37.000000000 +0200
+++ linux-2.6.30-rc8-fast/drivers/md/dm-delay.c	2009-06-09 04:01:46.000000000 +0200
@@ -72,6 +72,7 @@ static void flush_bios(struct bio *bio)
 	while (bio) {
 		n = bio->bi_next;
 		bio->bi_next = NULL;
+		bio->bi_flags |= (1 << BIO_RW_UNPLUG);
 		generic_make_request(bio);
 		bio = n;
 	}