===== drivers/block/ll_rw_blk.c 1.288 vs edited =====
Index: linux-2.6.11-ck7/drivers/block/ll_rw_blk.c
===================================================================
--- linux-2.6.11-ck7.orig/drivers/block/ll_rw_blk.c	2005-05-01 10:36:07.000000000 +1000
+++ linux-2.6.11-ck7/drivers/block/ll_rw_blk.c	2005-05-01 10:36:07.000000000 +1000
@@ -1509,6 +1509,15 @@ request_queue_t *blk_init_queue(request_
 	if (blk_init_free_list(q))
 		goto out_init;
 
+	/*
+	 * if caller didn't supply a lock, they get per-queue locking with
+	 * our embedded lock
+	 */
+	if (!lock) {
+		spin_lock_init(&q->__queue_lock);
+		lock = &q->__queue_lock;
+	}
+
 	q->request_fn		= rfn;
 	q->back_merge_fn       	= ll_back_merge_fn;
 	q->front_merge_fn      	= ll_front_merge_fn;
Index: linux-2.6.11-ck7/drivers/scsi/scsi_lib.c
===================================================================
--- linux-2.6.11-ck7.orig/drivers/scsi/scsi_lib.c	2005-05-01 10:36:07.000000000 +1000
+++ linux-2.6.11-ck7/drivers/scsi/scsi_lib.c	2005-05-01 10:36:07.000000000 +1000
@@ -349,9 +349,9 @@ void scsi_device_unbusy(struct scsi_devi
 		     shost->host_failed))
 		scsi_eh_wakeup(shost);
 	spin_unlock(shost->host_lock);
-	spin_lock(&sdev->sdev_lock);
+	spin_lock(sdev->request_queue->queue_lock);
 	sdev->device_busy--;
-	spin_unlock_irqrestore(&sdev->sdev_lock, flags);
+	spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
 }
 
 /*
@@ -1353,7 +1353,7 @@ struct request_queue *scsi_alloc_queue(s
 	struct Scsi_Host *shost = sdev->host;
 	struct request_queue *q;
 
-	q = blk_init_queue(scsi_request_fn, &sdev->sdev_lock);
+	q = blk_init_queue(scsi_request_fn, NULL);
 	if (!q)
 		return NULL;
 
Index: linux-2.6.11-ck7/drivers/scsi/scsi_scan.c
===================================================================
--- linux-2.6.11-ck7.orig/drivers/scsi/scsi_scan.c	2005-05-01 10:36:07.000000000 +1000
+++ linux-2.6.11-ck7/drivers/scsi/scsi_scan.c	2005-05-01 10:36:07.000000000 +1000
@@ -246,7 +246,6 @@ static struct scsi_device *scsi_alloc_sd
 	 */
 	sdev->borken = 1;
 
-	spin_lock_init(&sdev->sdev_lock);
 	sdev->request_queue = scsi_alloc_queue(sdev);
 	if (!sdev->request_queue)
 		goto out_free_dev;
Index: linux-2.6.11-ck7/include/linux/blkdev.h
===================================================================
--- linux-2.6.11-ck7.orig/include/linux/blkdev.h	2005-05-01 10:36:07.000000000 +1000
+++ linux-2.6.11-ck7/include/linux/blkdev.h	2005-05-01 10:36:07.000000000 +1000
@@ -352,8 +352,11 @@ struct request_queue
 	unsigned long		queue_flags;
 
 	/*
-	 * protects queue structures from reentrancy
+	 * protects queue structures from reentrancy. ->__queue_lock should
+	 * _never_ be used directly, it is queue private. always use
+	 * ->queue_lock.
 	 */
+	spinlock_t		__queue_lock;
 	spinlock_t		*queue_lock;
 
 	/*
Index: linux-2.6.11-ck7/include/scsi/scsi_device.h
===================================================================
--- linux-2.6.11-ck7.orig/include/scsi/scsi_device.h	2005-05-01 10:36:07.000000000 +1000
+++ linux-2.6.11-ck7/include/scsi/scsi_device.h	2005-05-01 10:36:07.000000000 +1000
@@ -44,7 +44,6 @@ struct scsi_device {
 	struct list_head    same_target_siblings; /* just the devices sharing same target id */
 
 	volatile unsigned short device_busy;	/* commands actually active on low-level */
-	spinlock_t sdev_lock;           /* also the request queue_lock */
 	spinlock_t list_lock;
 	struct list_head cmd_list;	/* queue of in use SCSI Command structures */
 	struct list_head starved_entry;