Re: blk request timeout handler against 2.6.26

[malahal@us.ibm.com]

Add missing queue lock in blk_complete_request(). Ran disktest for few
hours and it works fine with this patch.

Signed-off-by: Malahal Naineni <malahal@us.ibm.com>

diff -r c06b3eb1f516 block/blk-core.c
--- a/block/blk-core.c	Wed May 07 20:07:12 2008 -0700
+++ b/block/blk-core.c	Wed May 07 20:17:03 2008 -0700
@@ -1856,6 +1856,10 @@
  */
 void blk_complete_request(struct request *req)
 {
+	unsigned long flags;
+	struct request_queue *q = req->q;
+	int rc;
+
 	/*
 	 * We don't have to worry about this one timing out any more.
 	 * If we are unable to remove the timer, then the command
@@ -1864,7 +1868,10 @@
 	 * that function could really be.  It might be on another processor,
 	 * etc, etc.
 	 */
-	if (!blk_delete_timer(req))
+	spin_lock_irqsave(q->queue_lock, flags);
+	rc = blk_delete_timer(req);
+	spin_unlock_irqrestore(q->queue_lock, flags);
+	if (!rc)
 		return;
 
 	__blk_complete_request(req);