X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=drivers%2Fmtd%2Fmtd_blkdevs.c;h=ca385697446ece7ebfe387a4cd99b41cbca9ebbc;hb=29a6ccca3869bbe33879dae0cd7df2a1559eff54;hp=e0a2373bf0e2fe5ad6fc9423d5db19f96e25de5a;hpb=0acd2201920d0968919f4f5797d63f7b6f2b19d4;p=firefly-linux-kernel-4.4.55.git

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index e0a2373bf0e2..ca385697446e 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -40,7 +40,7 @@
 static LIST_HEAD(blktrans_majors);
 static DEFINE_MUTEX(blktrans_ref_mutex);
 
-void blktrans_dev_release(struct kref *kref)
+static void blktrans_dev_release(struct kref *kref)
 {
 	struct mtd_blktrans_dev *dev =
 		container_of(kref, struct mtd_blktrans_dev, ref);
@@ -67,7 +67,7 @@ unlock:
 	return dev;
 }
 
-void blktrans_dev_put(struct mtd_blktrans_dev *dev)
+static void blktrans_dev_put(struct mtd_blktrans_dev *dev)
 {
 	mutex_lock(&blktrans_ref_mutex);
 	kref_put(&dev->ref, blktrans_dev_release);
@@ -119,18 +119,43 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr,
 	}
 }
 
+int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev)
+{
+	if (kthread_should_stop())
+		return 1;
+
+	return dev->bg_stop;
+}
+EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background);
+
 static int mtd_blktrans_thread(void *arg)
 {
 	struct mtd_blktrans_dev *dev = arg;
+	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 (!kthread_should_stop()) {
 		int res;
 
+		dev->bg_stop = false;
 		if (!req && !(req = blk_fetch_request(rq))) {
+			if (tr->background && !background_done) {
+				spin_unlock_irq(rq->queue_lock);
+				mutex_lock(&dev->lock);
+				tr->background(dev);
+				mutex_unlock(&dev->lock);
+				spin_lock_irq(rq->queue_lock);
+				/*
+				 * Do background processing just once per idle
+				 * period.
+				 */
+				background_done = !dev->bg_stop;
+				continue;
+			}
 			set_current_state(TASK_INTERRUPTIBLE);
 
 			if (kthread_should_stop())
@@ -152,6 +177,8 @@ static int mtd_blktrans_thread(void *arg)
 
 		if (!__blk_end_request_cur(req, res))
 			req = NULL;
+
+		background_done = 0;
 	}
 
 	if (req)
@@ -172,8 +199,10 @@ static void mtd_blktrans_request(struct request_queue *rq)
 	if (!dev)
 		while ((req = blk_fetch_request(rq)) != NULL)
 			__blk_end_request_all(req, -ENODEV);
-	else
+	else {
+		dev->bg_stop = true;
 		wake_up_process(dev->thread);
+	}
 }
 
 static int blktrans_open(struct block_device *bdev, fmode_t mode)
@@ -192,15 +221,33 @@ static int blktrans_open(struct block_device *bdev, fmode_t mode)
 	kref_get(&dev->ref);
 	__module_get(dev->tr->owner);
 
-	if (dev->mtd) {
-		ret = dev->tr->open ? dev->tr->open(dev) : 0;
-		__get_mtd_device(dev->mtd);
+	if (!dev->mtd)
+		goto unlock;
+
+	if (dev->tr->open) {
+		ret = dev->tr->open(dev);
+		if (ret)
+			goto error_put;
 	}
 
+	ret = __get_mtd_device(dev->mtd);
+	if (ret)
+		goto error_release;
+
 unlock:
 	mutex_unlock(&dev->lock);
 	blktrans_dev_put(dev);
 	return ret;
+
+error_release:
+	if (dev->tr->release)
+		dev->tr->release(dev);
+error_put:
+	module_put(dev->tr->owner);
+	kref_put(&dev->ref, blktrans_dev_release);
+	mutex_unlock(&dev->lock);
+	blktrans_dev_put(dev);
+	return ret;
 }
 
 static int blktrans_release(struct gendisk *disk, fmode_t mode)
@@ -379,9 +426,10 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
 	new->rq->queuedata = new;
 	blk_queue_logical_block_size(new->rq, tr->blksize);
 
-	if (tr->discard)
-		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
-					new->rq);
+	if (tr->discard) {
+		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, new->rq);
+		new->rq->limits.max_discard_sectors = UINT_MAX;
+	}
 
 	gd->queue = new->rq;