1 files changed, 63 insertions, 37 deletions

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 6a41dfa3c36b..b0d44f9214b0 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -27,6 +27,7 @@
 #include <linux/mtd/blktrans.h>
 #include <linux/mtd/mtd.h>
 #include <linux/blkdev.h>
+#include <linux/blk-mq.h>
 #include <linux/blkpg.h>
 #include <linux/spinlock.h>
 #include <linux/hdreg.h>
@@ -45,6 +46,8 @@ static void blktrans_dev_release(struct kref *kref)
 
 	dev->disk->private_data = NULL;
 	blk_cleanup_queue(dev->rq);
+	blk_mq_free_tag_set(dev->tag_set);
+	kfree(dev->tag_set);
 	put_disk(dev->disk);
 	list_del(&dev->list);
 	kfree(dev);
@@ -134,28 +137,39 @@ int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev)
 }
 EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background);
 
-static void mtd_blktrans_work(struct work_struct *work)
+static struct request *mtd_next_request(struct mtd_blktrans_dev *dev)
+{
+	struct request *rq;
+
+	rq = list_first_entry_or_null(&dev->rq_list, struct request, queuelist);
+	if (rq) {
+		list_del_init(&rq->queuelist);
+		blk_mq_start_request(rq);
+		return rq;
+	}
+
+	return NULL;
+}
+
+static void mtd_blktrans_work(struct mtd_blktrans_dev *dev)
+	__releases(&dev->queue_lock)
+	__acquires(&dev->queue_lock)
 {
-	struct mtd_blktrans_dev *dev =
-		container_of(work, struct mtd_blktrans_dev, work);
 	struct mtd_blktrans_ops *tr = dev->tr;
-	struct request_queue *rq = dev->rq;
 	struct request *req = NULL;
 	int background_done = 0;
 
-	spin_lock_irq(rq->queue_lock);
-
 	while (1) {
 		blk_status_t res;
 
 		dev->bg_stop = false;
-		if (!req && !(req = blk_fetch_request(rq))) {
+		if (!req && !(req = mtd_next_request(dev))) {
 			if (tr->background && !background_done) {
-				spin_unlock_irq(rq->queue_lock);
+				spin_unlock_irq(&dev->queue_lock);
 				mutex_lock(&dev->lock);
 				tr->background(dev);
 				mutex_unlock(&dev->lock);
-				spin_lock_irq(rq->queue_lock);
+				spin_lock_irq(&dev->queue_lock);
 				/*
 				 * Do background processing just once per idle
 				 * period.
@@ -166,35 +180,39 @@ static void mtd_blktrans_work(struct work_struct *work)
 			break;
 		}
 
-		spin_unlock_irq(rq->queue_lock);
+		spin_unlock_irq(&dev->queue_lock);
 
 		mutex_lock(&dev->lock);
 		res = do_blktrans_request(dev->tr, dev, req);
 		mutex_unlock(&dev->lock);
 
-		spin_lock_irq(rq->queue_lock);
-
-		if (!__blk_end_request_cur(req, res))
+		if (!blk_update_request(req, res, blk_rq_cur_bytes(req))) {
+			__blk_mq_end_request(req, res);
 			req = NULL;
+		}
 
 		background_done = 0;
+		spin_lock_irq(&dev->queue_lock);
 	}
-
-	spin_unlock_irq(rq->queue_lock);
 }
 
-static void mtd_blktrans_request(struct request_queue *rq)
+static blk_status_t mtd_queue_rq(struct blk_mq_hw_ctx *hctx,
+				 const struct blk_mq_queue_data *bd)
 {
 	struct mtd_blktrans_dev *dev;
-	struct request *req = NULL;
 
-	dev = rq->queuedata;
+	dev = hctx->queue->queuedata;
+	if (!dev) {
+		blk_mq_start_request(bd->rq);
+		return BLK_STS_IOERR;
+	}
+
+	spin_lock_irq(&dev->queue_lock);
+	list_add_tail(&bd->rq->queuelist, &dev->rq_list);
+	mtd_blktrans_work(dev);
+	spin_unlock_irq(&dev->queue_lock);
 
-	if (!dev)
-		while ((req = blk_fetch_request(rq)) != NULL)
-			__blk_end_request_all(req, BLK_STS_IOERR);
-	else
-		queue_work(dev->wq, &dev->work);
+	return BLK_STS_OK;
 }
 
 static int blktrans_open(struct block_device *bdev, fmode_t mode)
@@ -329,6 +347,10 @@ static const struct block_device_operations mtd_block_ops = {
 	.getgeo		= blktrans_getgeo,
 };
 
+static const struct blk_mq_ops mtd_mq_ops = {
+	.queue_rq	= mtd_queue_rq,
+};
+
 int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
 {
 	struct mtd_blktrans_ops *tr = new->tr;
@@ -416,11 +438,20 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
 
 	/* Create the request queue */
 	spin_lock_init(&new->queue_lock);
-	new->rq = blk_init_queue(mtd_blktrans_request, &new->queue_lock);
+	INIT_LIST_HEAD(&new->rq_list);
 
-	if (!new->rq)
+	new->tag_set = kzalloc(sizeof(*new->tag_set), GFP_KERNEL);
+	if (!new->tag_set)
 		goto error3;
 
+	new->rq = blk_mq_init_sq_queue(new->tag_set, &mtd_mq_ops, 2,
+				BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_BLOCKING);
+	if (IS_ERR(new->rq)) {
+		ret = PTR_ERR(new->rq);
+		new->rq = NULL;
+		goto error4;
+	}
+
 	if (tr->flush)
 		blk_queue_write_cache(new->rq, true, false);
 
@@ -437,13 +468,6 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
 
 	gd->queue = new->rq;
 
-	/* Create processing workqueue */
-	new->wq = alloc_workqueue("%s%d", 0, 0,
-				  tr->name, new->mtd->index);
-	if (!new->wq)
-		goto error4;
-	INIT_WORK(&new->work, mtd_blktrans_work);
-
 	if (new->readonly)
 		set_disk_ro(gd, 1);
 
@@ -456,7 +480,7 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
 	}
 	return 0;
 error4:
-	blk_cleanup_queue(new->rq);
+	kfree(new->tag_set);
 error3:
 	put_disk(new->disk);
 error2:
@@ -481,15 +505,17 @@ int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
 	/* Stop new requests to arrive */
 	del_gendisk(old->disk);
 
-	/* Stop workqueue. This will perform any pending request. */
-	destroy_workqueue(old->wq);
-
 	/* Kill current requests */
 	spin_lock_irqsave(&old->queue_lock, flags);
 	old->rq->queuedata = NULL;
-	blk_start_queue(old->rq);
 	spin_unlock_irqrestore(&old->queue_lock, flags);
 
+	/* freeze+quiesce queue to ensure all requests are flushed */
+	blk_mq_freeze_queue(old->rq);
+	blk_mq_quiesce_queue(old->rq);
+	blk_mq_unquiesce_queue(old->rq);
+	blk_mq_unfreeze_queue(old->rq);
+
 	/* If the device is currently open, tell trans driver to close it,
 		then put mtd device, and don't touch it again */
 	mutex_lock(&old->lock);