Signed-off-by: Brian King <brking@us.ibm.com>
---

 linux-2.6.8-rc2-bjking1/drivers/block/ll_rw_blk.c |   47 +++++++++++++++++-----
 linux-2.6.8-rc2-bjking1/include/scsi/scsi_tcq.h   |    8 +++
 2 files changed, 46 insertions(+), 9 deletions(-)

diff -puN drivers/block/ll_rw_blk.c~blk_queue_free_tags_bug2 drivers/block/ll_rw_blk.c
--- linux-2.6.8-rc2/drivers/block/ll_rw_blk.c~blk_queue_free_tags_bug2	2004-08-02 17:02:43.000000000 -0500
+++ linux-2.6.8-rc2-bjking1/drivers/block/ll_rw_blk.c	2004-08-03 10:45:14.000000000 -0500
@@ -482,15 +482,14 @@ struct request *blk_queue_find_tag(reque
 EXPORT_SYMBOL(blk_queue_find_tag);
 
 /**
- * blk_queue_free_tags - release tag maintenance info
+ * _blk_queue_free_tags - release tag maintenance info
  * @q:  the request queue for the device
  *
  *  Notes:
  *    blk_cleanup_queue() will take care of calling this function, if tagging
- *    has been used. So there's usually no need to call this directly, unless
- *    tagging is just being disabled but the queue remains in function.
+ *    has been used.
  **/
-void blk_queue_free_tags(request_queue_t *q)
+static void _blk_queue_free_tags(request_queue_t *q)
 {
 	struct blk_queue_tag *bqt = q->queue_tags;
 
@@ -511,7 +510,21 @@ void blk_queue_free_tags(request_queue_t
 	}
 
 	q->queue_tags = NULL;
-	q->queue_flags &= ~(1 << QUEUE_FLAG_QUEUED);
+	clear_bit(QUEUE_FLAG_QUEUED, &q->queue_flags);
+}
+
+/**
+ * blk_queue_free_tags - release tag maintenance info
+ * @q:  the request queue for the device
+ *
+ *  Notes:
+ *    blk_cleanup_queue() will take care of calling this function, if tagging
+ *    has been used. So there's usually no need to call this directly, unless
+ *    tagging is just being disabled but the queue remains in function.
+ **/
+void blk_queue_free_tags(request_queue_t *q)
+{
+	clear_bit(QUEUE_FLAG_QUEUED, &q->queue_flags);
 }
 
 EXPORT_SYMBOL(blk_queue_free_tags);
@@ -564,13 +577,22 @@ fail:
 int blk_queue_init_tags(request_queue_t *q, int depth,
 			struct blk_queue_tag *tags)
 {
-	if (!tags) {
+	int rc;
+
+	BUG_ON(tags && q->queue_tags && tags != q->queue_tags);
+
+	if (!tags && !q->queue_tags) {
 		tags = kmalloc(sizeof(struct blk_queue_tag), GFP_ATOMIC);
 		if (!tags)
 			goto fail;
 
 		if (init_tag_map(q, tags, depth))
 			goto fail;
+	} else if (q->queue_tags) {
+		if ((rc = blk_queue_resize_tags(q, depth)))
+			return rc;
+		set_bit(QUEUE_FLAG_QUEUED, &q->queue_flags);
+		return 0;
 	} else
 		atomic_inc(&tags->refcnt);
 
@@ -578,7 +600,7 @@ int blk_queue_init_tags(request_queue_t 
 	 * assign it, all done
 	 */
 	q->queue_tags = tags;
-	q->queue_flags |= (1 << QUEUE_FLAG_QUEUED);
+	set_bit(QUEUE_FLAG_QUEUED, &q->queue_flags);
 	return 0;
 fail:
 	kfree(tags);
@@ -1333,8 +1355,8 @@ void blk_cleanup_queue(request_queue_t *
 	if (rl->rq_pool)
 		mempool_destroy(rl->rq_pool);
 
-	if (blk_queue_tagged(q))
-		blk_queue_free_tags(q);
+	if (q->queue_tags)
+		_blk_queue_free_tags(q);
 
 	kmem_cache_free(requestq_cachep, q);
 }
@@ -2034,6 +2056,13 @@ void __blk_put_request(request_queue_t *
 
 		elv_completed_request(q, req);
 
+		if (!list_empty(&req->queuelist)) {
+			if (req->flags & REQ_QUEUED)
+				printk(KERN_ERR "REQ_QUEUED still set in __blk_put_request\n");
+			printk(KERN_ERR "req: %p, q: %p, req_flags: %lx, q_flags: %lx\n",
+			       req, q, req->flags, q->queue_flags);
+		}
+
 		BUG_ON(!list_empty(&req->queuelist));
 
 		blk_free_request(q, req);
diff -puN include/scsi/scsi_tcq.h~blk_queue_free_tags_bug2 include/scsi/scsi_tcq.h
--- linux-2.6.8-rc2/include/scsi/scsi_tcq.h~blk_queue_free_tags_bug2	2004-08-02 17:02:43.000000000 -0500
+++ linux-2.6.8-rc2-bjking1/include/scsi/scsi_tcq.h	2004-08-02 17:02:43.000000000 -0500
@@ -25,9 +25,13 @@
  **/
 static inline void scsi_activate_tcq(struct scsi_device *sdev, int depth)
 {
+        unsigned long flags;
+
         if (sdev->tagged_supported) {
+		spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
 		if (!blk_queue_tagged(sdev->request_queue))
 			blk_queue_init_tags(sdev->request_queue, depth, NULL);
+		spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
 		scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth);
         }
 }
@@ -38,8 +42,12 @@ static inline void scsi_activate_tcq(str
  **/
 static inline void scsi_deactivate_tcq(struct scsi_device *sdev, int depth)
 {
+	unsigned long flags;
+
+	spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
 	if (blk_queue_tagged(sdev->request_queue))
 		blk_queue_free_tags(sdev->request_queue);
+	spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
 	scsi_adjust_queue_depth(sdev, 0, depth);
 }
 
_