[PATCH 3/5] [MTD] Support 'discard sectors' operation in translation layer support core

[David Woodhouse <dwmw2@infradead.org>]

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
---
 drivers/mtd/mtd_blkdevs.c    |   13 +++++++++++++
 include/linux/mtd/blktrans.h |    2 ++
 2 files changed, 15 insertions(+), 0 deletions(-)

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 9ff007c..0ef1d4b 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -32,6 +32,13 @@ 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_DISCARD;
+	return 0;
+}
+
 static int do_blktrans_request(struct mtd_blktrans_ops *tr,
 			       struct mtd_blktrans_dev *dev,
 			       struct request *req)
@@ -44,6 +51,9 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr,
 
 	buf = req->buffer;
 
+	if (req->cmd_type == REQ_TYPE_DISCARD)
+		return !tr->discard(dev, block, nsect);
+
 	if (!blk_fs_request(req))
 		return 0;
 
@@ -367,6 +377,9 @@ 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_discard(tr->blkcore_priv->rq, blktrans_discard_request);
+
 	tr->blkshift = ffs(tr->blksize) - 1;
 
 	tr->blkcore_priv->thread = kthread_run(mtd_blktrans_thread, tr,
diff --git a/include/linux/mtd/blktrans.h b/include/linux/mtd/blktrans.h
index 310e616..8b4aa05 100644
--- a/include/linux/mtd/blktrans.h
+++ b/include/linux/mtd/blktrans.h
@@ -41,6 +41,8 @@ struct mtd_blktrans_ops {
 		    unsigned long block, char *buffer);
 	int (*writesect)(struct mtd_blktrans_dev *dev,
 		     unsigned long block, char *buffer);
+	int (*discard)(struct mtd_blktrans_dev *dev,
+		       unsigned long block, unsigned nr_blocks);
 
 	/* Block layer ioctls */
 	int (*getgeo)(struct mtd_blktrans_dev *dev, struct hd_geometry *geo);
-- 
1.5.5.1


-- 
David Woodhouse                            Open Source Technology Centre
David.Woodhouse@intel.com                              Intel Corporation