1 files changed, 26 insertions, 24 deletions

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 839eed84..681d5ac 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -1,6 +1,4 @@
 /*
- * $Id: mtd_blkdevs.c,v 1.27 2005/11/07 11:14:20 gleixner Exp $
- *
  * (C) 2003 David Woodhouse <dwmw2@infradead.org>
  *
  * Interface to Linux 2.5 block layer for MTD 'translation layers'.
@@ -34,6 +32,14 @@ struct mtd_blkcore_priv {
 	spinlock_t queue_lock;
 };
 
+static int blktrans_discard_request(struct request_queue *q,
+				    struct request *req)
+{
+	req->cmd_type = REQ_TYPE_LINUX_BLOCK;
+	req->cmd[0] = REQ_LB_OP_DISCARD;
+	return 0;
+}
+
 static int do_blktrans_request(struct mtd_blktrans_ops *tr,
 			       struct mtd_blktrans_dev *dev,
 			       struct request *req)
@@ -46,6 +52,10 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr,
 
 	buf = req->buffer;
 
+	if (req->cmd_type == REQ_TYPE_LINUX_BLOCK &&
+	    req->cmd[0] == REQ_LB_OP_DISCARD)
+		return !tr->discard(dev, block, nsect);
+
 	if (!blk_fs_request(req))
 		return 0;
 
@@ -212,7 +222,7 @@ static struct block_device_operations mtd_blktrans_ops = {
 int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
 {
 	struct mtd_blktrans_ops *tr = new->tr;
-	struct list_head *this;
+	struct mtd_blktrans_dev *d;
 	int last_devnum = -1;
 	struct gendisk *gd;
 
@@ -221,8 +231,7 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
 		BUG();
 	}
 
-	list_for_each(this, &tr->devs) {
-		struct mtd_blktrans_dev *d = list_entry(this, struct mtd_blktrans_dev, list);
+	list_for_each_entry(d, &tr->devs, list) {
 		if (new->devnum == -1) {
 			/* Use first free number */
 			if (d->devnum != last_devnum+1) {
@@ -309,33 +318,24 @@ int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
 
 static void blktrans_notify_remove(struct mtd_info *mtd)
 {
-	struct list_head *this, *this2, *next;
-
-	list_for_each(this, &blktrans_majors) {
-		struct mtd_blktrans_ops *tr = list_entry(this, struct mtd_blktrans_ops, list);
-
-		list_for_each_safe(this2, next, &tr->devs) {
-			struct mtd_blktrans_dev *dev = list_entry(this2, struct mtd_blktrans_dev, list);
+	struct mtd_blktrans_ops *tr;
+	struct mtd_blktrans_dev *dev, *next;
 
+	list_for_each_entry(tr, &blktrans_majors, list)
+		list_for_each_entry_safe(dev, next, &tr->devs, list)
 			if (dev->mtd == mtd)
 				tr->remove_dev(dev);
-		}
-	}
 }
 
 static void blktrans_notify_add(struct mtd_info *mtd)
 {
-	struct list_head *this;
+	struct mtd_blktrans_ops *tr;
 
 	if (mtd->type == MTD_ABSENT)
 		return;
 
-	list_for_each(this, &blktrans_majors) {
-		struct mtd_blktrans_ops *tr = list_entry(this, struct mtd_blktrans_ops, list);
-
+	list_for_each_entry(tr, &blktrans_majors, list)
 		tr->add_mtd(tr, mtd);
-	}
-
 }
 
 static struct mtd_notifier blktrans_notifier = {
@@ -379,6 +379,10 @@ int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
 
 	tr->blkcore_priv->rq->queuedata = tr;
 	blk_queue_hardsect_size(tr->blkcore_priv->rq, tr->blksize);
+	if (tr->discard)
+		blk_queue_set_discard(tr->blkcore_priv->rq,
+				      blktrans_discard_request);
+
 	tr->blkshift = ffs(tr->blksize) - 1;
 
 	tr->blkcore_priv->thread = kthread_run(mtd_blktrans_thread, tr,
@@ -406,7 +410,7 @@ int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
 
 int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
 {
-	struct list_head *this, *next;
+	struct mtd_blktrans_dev *dev, *next;
 
 	mutex_lock(&mtd_table_mutex);
 
@@ -416,10 +420,8 @@ int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
 	/* Remove it from the list of active majors */
 	list_del(&tr->list);
 
-	list_for_each_safe(this, next, &tr->devs) {
-		struct mtd_blktrans_dev *dev = list_entry(this, struct mtd_blktrans_dev, list);
+	list_for_each_entry_safe(dev, next, &tr->devs, list)
 		tr->remove_dev(dev);
-	}
 
 	blk_cleanup_queue(tr->blkcore_priv->rq);
 	unregister_blkdev(tr->major, tr->name);