From eae9acd13a8d14b50c00a961fa959606f34bbd92 Mon Sep 17 00:00:00 2001
From: David Woodhouse <David.Woodhouse@intel.com>
Date: Tue, 5 Aug 2008 18:08:25 +0100
Subject: [PATCH] Support 'discard sectors' operation in translation layer
support core
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---
drivers/mtd/mtd_blkdevs.c | 16 ++++++++++++++++
include/linux/blkdev.h | 1 +
include/linux/mtd/blktrans.h | 2 ++
3 files changed, 19 insertions(+)
diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 9ff007c4962c..681d5aca2af4 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -32,6 +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)
@@ -44,6 +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;
@@ -367,6 +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,
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 26ececbbebe2..727886d25c4e 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -81,6 +81,7 @@ enum {
*/
REQ_LB_OP_EJECT = 0x40, /* eject request */
REQ_LB_OP_FLUSH = 0x41, /* flush device */
+ REQ_LB_OP_DISCARD = 0x42, /* discard sectors */
};
/*
diff --git a/include/linux/mtd/blktrans.h b/include/linux/mtd/blktrans.h
index 310e61606415..8b4aa0523db7 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);
--
2.20.1