mmc_block: fix queue cleanup

The main bug was that 'blk_cleanup_queue()' was called while the block
device could still be in use, for example, because the card was removed
while files were still open.

In addition, to be sure that 'mmc_request()' will get called for all new
requests (so it can error them out), the queue is emptied during cleanup.
This is done after the worker thread is stopped to avoid racing with it.

Finally, it is not a device error for this to be happening, so quiet the
(sometimes very many) error messages.
Signed-off-by: NAdrian Hunter <adrian.hunter@nokia.com>
Cc: <linux-mmc@vger.kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/mmc/card/block.c

@@ -91,6 +91,8 @@ static void mmc_blk_put(struct mmc_blk_data *md)
 		if (!devmaj)
 			devidx = md->disk->first_minor >> MMC_SHIFT;
 
+		blk_cleanup_queue(md->queue.queue);
+
 		__clear_bit(devidx, dev_use);
 
 		put_disk(md->disk);

drivers/mmc/card/queue.c

@@ -90,9 +90,10 @@ static void mmc_request(struct request_queue *q)
 	struct request *req;
 
 	if (!mq) {
-		printk(KERN_ERR "MMC: killing requests for dead queue\n");
-		while ((req = blk_fetch_request(q)) != NULL)
+		while ((req = blk_fetch_request(q)) != NULL) {
+			req->cmd_flags |= REQ_QUIET;
 			__blk_end_request_all(req, -EIO);
+		}
 		return;
 	}
 
@@ -223,17 +224,18 @@ void mmc_cleanup_queue(struct mmc_queue *mq)
 	struct request_queue *q = mq->queue;
 	unsigned long flags;
 
-	/* Mark that we should start throwing out stragglers */
-	spin_lock_irqsave(q->queue_lock, flags);
-	q->queuedata = NULL;
-	spin_unlock_irqrestore(q->queue_lock, flags);
-
 	/* Make sure the queue isn't suspended, as that will deadlock */
 	mmc_queue_resume(mq);
 
 	/* Then terminate our worker thread */
 	kthread_stop(mq->thread);
 
+	/* Empty the queue */
+	spin_lock_irqsave(q->queue_lock, flags);
+	q->queuedata = NULL;
+	blk_start_queue(q);
+	spin_unlock_irqrestore(q->queue_lock, flags);
+
  	if (mq->bounce_sg)
  		kfree(mq->bounce_sg);
  	mq->bounce_sg = NULL;
@@ -245,8 +247,6 @@ void mmc_cleanup_queue(struct mmc_queue *mq)
 		kfree(mq->bounce_buf);
 	mq->bounce_buf = NULL;
 
-	blk_cleanup_queue(mq->queue);
-
 	mq->card = NULL;
 }
 EXPORT_SYMBOL(mmc_cleanup_queue);