dm-crypt: don't use write queue

Don't use write queue and allocate write data directly from the request routine.
There is no need to bounce requests through a queue.

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

---
 drivers/md/dm-crypt.c |   11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

Index: linux-3.2-fast/drivers/md/dm-crypt.c
===================================================================
--- linux-3.2-fast.orig/drivers/md/dm-crypt.c	2012-02-18 17:05:49.000000000 +0100
+++ linux-3.2-fast/drivers/md/dm-crypt.c	2012-02-18 17:11:10.000000000 +0100
@@ -1280,10 +1280,8 @@ static void kcryptd_crypt(struct work_st
 {
 	struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
 
-	if (bio_data_dir(io->base_bio) == READ)
-		kcryptd_crypt_read_convert(io);
-	else
-		kcryptd_crypt_write_convert(io);
+	BUG_ON(bio_data_dir(io->base_bio) != READ);
+	kcryptd_crypt_read_convert(io);
 }
 
 static void kcryptd_queue_crypt(struct dm_crypt_io *io)
@@ -1855,8 +1853,9 @@ static int crypt_map(struct dm_target *t
 	if (bio_data_dir(io->base_bio) == READ) {
 		if (kcryptd_io_read(io, GFP_NOWAIT))
 			kcryptd_queue_io(io);
-	} else
-		kcryptd_queue_crypt(io);
+	} else {
+		kcryptd_crypt_write_convert(io);
+	}
 
 	return DM_MAPIO_SUBMITTED;
 }