1 files changed, 36 insertions, 6 deletions

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index e0a2373bf0e2..a534e1f0c348 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)
@@ -379,9 +408,10 @@ 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;