[PATCH 6/8] blktrans: flush all requests before we remove the device

[Maxim Levitsky]

>From 6d5a70a18bea40bfc354e73d7fde5042465fc534 Mon Sep 17 00:00:00 2001
From: Maxim Levitsky <maximlevitsky at gmail.com>
Date: Sat, 23 Jan 2010 02:09:11 +0200
Subject: [PATCH 6/8] blktrans: flush all requests before we remove the device

Flush all requests, so we can be sure we don't deadlock the system later
when we remove the disk queue.

Signed-off-by: Maxim Levitsky <maximlevitsky at gmail.com>
---
 drivers/mtd/mtd_blkdevs.c |   14 +++++++++++++-
 1 files changed, 13 insertions(+), 1 deletions(-)

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index f165115..33bdef1 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -115,7 +115,13 @@ static int mtd_blktrans_thread(void *arg)
 static void mtd_blktrans_request(struct request_queue *rq)
 {
 	struct mtd_blktrans_dev *dev = rq->queuedata;
-	wake_up_process(dev->thread);
+	struct request *req = NULL;
+
+	if (dev->deleted)
+		while ((req = blk_fetch_request(rq)) != NULL)
+			__blk_end_request_all(req, -ENODEV);
+	else
+		wake_up_process(dev->thread);
 }
 

@@ -359,6 +365,8 @@ error1:
 
 int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
 {
+	unsigned long flags;
+
 	if (mutex_trylock(&mtd_table_mutex)) {
 		mutex_unlock(&mtd_table_mutex);
 		BUG();
@@ -369,7 +377,11 @@ int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
 	/* stop new requests to arrive */
 	del_gendisk(old->disk);
 
+	/* flush current requests */
+	spin_lock_irqsave(&old->queue_lock, flags);
 	old->deleted = 1;
+	blk_start_queue(old->rq);
+	spin_unlock_irqrestore(&old->queue_lock, flags);
 
 	/* Stop the thread */
 	kthread_stop(old->thread);
-- 
1.6.3.3