[PATCH] md 2 of 22 - Make device plugging work for md/raid5

We embed a request_queue_t in the mddev structure and so
have a separate one for each mddev.
This is used for plugging (in raid5).

Given this embeded request_queue_t, md_make_request no-longer
needs to make from device number to mddev, but can map from
the queue to the mddev instead.

2 files changed, 3 insertions, 4 deletions

diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h
index 7b270a50487e..94ed760bd221 100644
--- a/include/linux/raid/md_k.h
+++ b/include/linux/raid/md_k.h
@@ -214,6 +214,8 @@ struct mddev_s
 	atomic_t			recovery_active; /* blocks scheduled, but not written */
 	wait_queue_head_t		recovery_wait;
 
+	request_queue_t			queue;	/* for plugging ... */
+
 	struct list_head		all_mddevs;
 };
 
diff --git a/include/linux/raid/raid5.h b/include/linux/raid/raid5.h
index 5c25120581a7..661783287da5 100644
--- a/include/linux/raid/raid5.h
+++ b/include/linux/raid/raid5.h
@@ -176,7 +176,7 @@ struct stripe_head {
  * is put on a "delayed" queue until there are no stripes currently
  * in a pre-read phase.  Further, if the "delayed" queue is empty when
  * a stripe is put on it then we "plug" the queue and do not process it
- * until an unplg call is made. (the tq_disk list is run).
+ * until an unplug call is made. (blk_run_queues is run).
  *
  * When preread is initiated on a stripe, we set PREREAD_ACTIVE and add
  * it to the count of prereading stripes.
@@ -228,9 +228,6 @@ struct raid5_private_data {
 							 * waiting for 25% to be free
 							 */        
 	spinlock_t		device_lock;
-
-	int			plugged;
-	struct tq_struct	plug_tq;
 };
 
 typedef struct raid5_private_data raid5_conf_t;